Life Extension Magazine®
Which is the optimal antihypertensive combination in different diseases, a renin- angiotensin-aldosterone system inhibitor with a diuretic or with a calcium channel blocker?
Successful treatment of hypertension often requires the association of drugs from different classes. Combination therapy takes advantage of complementary mechanisms of action, in order to reach target blood pressure (BP) earlier and to minimize the side effects of medications. In the last decade, several randomized trials have demonstrated the efficacy of combining a renin-angiotensin-aldosterone system (RAAS) inhibitor with a calcium channel blocker (CCB) or with a diuretic in different populations. The ACCOMPLISH trial was the only large clinical trial that directly compared the two combination strategies. In hypertensive individuals at high cardiovascular risk, benazepril plus amlodipine was superior to benazepril plus hydrochlorothiazide in reducing the primary composite endpoint of cardiovascular events plus death from cardiovascular causes. Small randomized trials have evaluated the two combination therapies in surrogate endpoints, such as microalbuminuria, with contrasting results. Current European and American guidelines recommend combination therapy as first-line when BP is at least 20/10 mmHg above treatment goals. However, the choice of the best combination therapy is still debated: the National Institute for Health and Clinical Excellence guidelines recommend a RAAS inhibitor plus a CCB, while the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure guidelines underline the pivotal role of thiazide diuretics. The combination of a RAAS inhibitor with a CCB demonstrated the best efficacy in reducing cardiovascular endpoint. However, the combination of a RAAS inhibitor with a diuretic has shown beneficial results in particular subgroup of patients, such as patients with heart failure or with African American origin. This review will focus on the rationale and current evidences about combination therapy in the management of arterial hypertension.
Curr Pharm Des . 2013;19(21):3753-65.
Incidence of discontinuation of angiotensin-converting enzyme inhibitors due to cough, in a primary healthcare center in Singapore.
INTRODUCTION: The inci-dence of cough induced by angiotensin-converting enzyme (ACE) inhibitors has been reported to be 5%-20%, with less than half of affected patients requiring discontinuation due to persistent cough. However, the incidence in the local Asian population has not been studied. This study aimed to objectively evaluate the incidence of discontinuation of ACE inhibitors due to cough, in a primary healthcare center in Singapore. METHODS: We retrospectively reviewed the medical records, both electronic and written, of patients who attended Tampines Polyclinic to identify those who were newly prescribed ACE inhibitors. The written medical records were analyzed to identify patients who discontinued the use of ACE inhibitors and to find out the reasons for discontinuation. RESULTS: A total of 424 patients were identified during the study period. Out of the 424 patients, 129 (30.4%) discontinued the use of ACE inhibitors due to cough. Overall, 90 (21.2%) patients who were initially started on ACE inhibitors were eventually switched to angiotensin receptor blockers (ARBs). CONCLUSION: In our cohort, the incidence of discontinuation of ACE inhibitors due to cough is higher than most other studies. The relationship between ethnicity and tolerance of medications should not be underestimated. As there is a high incidence of discontinuation of ACE inhibitors due to cough in the local population, ARBs may be a reasonable substitute as a first-line medication, if clinically indicated.
Singapore Med J . 2014 Mar;55(3):146-9.
Comparative effectiveness of renin-angiotensin system blockers and other antihypertensive drugs in patients with diabetes: systematic review and Bayesian network meta-analysis.
OBJECTIVE: To assess the effects of different classes of antihypertensive treatments, including monotherapy and combination therapy, on survival and major renal outcomes in patients with diabetes. DESIGN: Systematic review and Bayesian network meta-analysis of randomized clinical trials. DATA SOURCES: Electronic literature search of PubMed, Medline, Scopus, and the Cochrane Library for studies published up to December 2011. STUDY SELECTION: Randomized clinical trials of antihypertensive therapy (angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), a blockers, b blockers, calcium channel blockers, diuretics, and their combinations) in patients with diabetes with a follow-up of at least 12 months, reporting all cause mortality, requirement for dialysis, or doubling of serum creatinine levels. DATA EXTRACTION: Bayesian network meta-analysis combined direct and indirect evidence to estimate the relative effects between treatments as well as the probabilities of ranking for treatments based on their protective effects. RESULTS: 63 trials with 36,917 participants were identified, including 2,400 deaths, 766 patients who required dialysis, and 1,099 patients whose serum creatinine level had doubled. Compared with placebo, only ACE inhibitors significantly reduced the doubling of serum creatinine levels (odds ratio 0.58, 95% credible interval 0.32 to 0.90), and only b blockers showed a significant difference in mortality (odds ratio 7.13, 95% credible interval 1.37 to 41.39).Comparisons among all treatments showed no statistical significance in the outcome of dialysis. Although the beneficial effects of ACE inhibitors compared with ARBs did not reach statistical significance, ACE inhibitors consistently showed higher probabilities of being in the superior ranking positions among all three outcomes. Although the protective effect of an ACE inhibitor plus calcium channel blocker compared with placebo was not statistically significant, the treatment ranking identified this combination therapy to have the greatest probability (73.9%) for being the best treatment on reducing mortality, followed by ACE inhibitor plus diuretic (12.5%), ACE inhibitors (2.0%), calcium channel blockers (1.2%), and ARBs (0.4%). CONCLUSIONS: Our analyses show the renoprotective effects and superiority of using ACE inhibitors in patients with diabetes, and available evidence is not able to show a better effect for ARBs compared with ACE inhibitors. Considering the cost of drugs, our findings support the use of ACE inhibitors as the first line antihypertensive agent in patients with diabetes. Calcium channel blockers might be the preferred treatment in combination with ACE inhibitors if adequate blood pressure control cannot be achieved by ACE inhibitors alone.
BMJ . 2013 Oct 24;347:f6008.
Olive (Olea europaea L.) leaf polyphenols improve insulin sensitivity in middle-aged overweight men: a randomized, placebo-controlled, crossover trial.
BACKGROUND: Olive plant leaves (Olea europaea L.) have been used for centuries in folk medicine to treat diabetes, but there are very limited data examining the effects of olive polyphenols on glucose homeostasis in humans. OBJECTIVE: To assess the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein, 9.7 mg hydroxytyrosol per day) on insulin action and cardiovascular risk factors in middle-aged overweight men. DESIGN: Randomized, double-blinded, placebo-controlled, crossover trial in New Zealand. 46 participants (aged 46.4 ± 5.5 years and BMI 28.0 ± 2.0 kg/m(2)) were randomized to receive capsules with olive leaf extract (OLE) or placebo for 12 weeks, crossing over to other treatment after a 6-week washout. Primary outcome was insulin sensitivity (Matsuda method). Secondary outcomes included glucose and insulin profiles, cytokines, lipid profile, body composition, 24-hour ambulatory blood pressure, and carotid intima-media thickness. RESULTS: Treatment evaluations were based on the intention-to-treat principle. All participants took >96% of prescribed capsules. OLE supplementation was associated with a 15% improvement in insulin sensitivity (p = 0.024) compared to placebo. There was also a 28% improvement in pancreatic b-cell responsiveness (p = 0.013). OLE supplementation also led to increased fasting interleukin-6 (p = 0.014), IGFBP-1 (p = 0.024), and IGFBP-2 (p = 0.015) concentrations. There were however, no effects on interleukin-8, TNF-a, ultra-sensitive CRP, lipid profile, ambulatory blood pressure, body composition, carotid intima-media thickness, or liver function. CONCLUSIONS: Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic b-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome.
PLoS One . 2013;8(3):e57622.
Vasorelaxant activity of extracts obtained from Apium graveolens: possible source for vasorelaxant molecules isolation with potential antihypertensive effect.
OBJECTIVE: To investigate vasorelaxant effect of organic extracts from Apium graveolens (A. graveolens) which is a part of a group of plants subjected to pharmacological and phytochemical study with the purpose of offering it as an ideal source for obtaining lead compounds for designing new therapeutic agents with potential vasorelaxant and antihypertensive effects. METHODS: An ex vivo method was employed to assess the vasorelaxant activity. This consisted of using rat aortic rings with and without endothelium precontracted with norepinephrine. RESULTS: All extracts caused concentration-dependent relaxation in precontracted aortic rings with and without endothelium; the most active extracts were Dichloromethane and Ethyl Acetate extracts from A. graveolens. These results suggested that secondary metabolites responsible for the vasorelaxant activity belong to a group of compounds of medium polarity. Also, our evidence showed that effect induced by dichloromethane and ethyl acetate extracts from A. graveolens is mediated probably by calcium antagonism. CONCLUSIONS: A. graveolens represents an ideal source for obtaining lead compounds for designing new therapeutic agents with potential vasorelaxant and antihypertensive effects.
Asian Pac J Trop Biomed . 2013 Oct;3(10):776-9.
Antihypertensive effect of celery seed on rat blood pressure in chronic administration.
This study investigated the effects of different celery (Apium graveolens) seed extracts on blood pressure (BP) in normotensive and deoxycorticosterone acetate-induced hypertensive rats. The hexanic, methanolic, and aqueous-ethanolic extracts were administered intraperitoneally and their effects on BP and heart rate (HR) were evaluated in comparison with spirnolactone as a diuretic and positive control. Also, the amount of n-butylphthalide (NBP), as an antihypertensive constituent, in each extract was determined by HPLC. The results indicated that all extracts decreased BP and increased the HR in hypertensive rats, but had no effect on normotensive rats. The data showed that administration of 300 mg/kg of hexanic, methanolic, and aqueous-ethanolic (20/80, v/v) extracts of the celery seed caused 38, 24, and 23 mmHg reduction in BP and 60, 25, and 27 beats per minute increase in the HR, respectively. Also, the HPLC analysis data revealed that the content of NBP in the hexanic extract was 3.7 and 4 times greater than methanolic and aqueous-ethanolic extracts. It can be concluded that celery seed extracts have antihypertensive properties, which appears to be attributable to the actions of its active hydrophobic constitutes such as NBP and can be considered as an antihypertensive agent in chronic treatment of elevated BP.
J Med Food . 2013 Jun;16(6):558-63.
A Pilot Study to Evaluate the Antihypertensive Effect of a Celery Extract in Mild to Moderate Hypertensive Patients
Objective: To evaluate the efficacy of a standardized extract of celery seed, 150 mg/d, supplying 85% 3-n-butylphthalide (3nB) in mild to moderate hypertensive patients. Study Design: A single-arm study of 30 mild to moderate hypertensive patients given the test medication following a 7-day wash out period. The primary clinical assessment was the effect on blood pressure at week 3 and week 6. Secondary measures were fasting blood levels of total cholesterol, LDL cholesterol, HDL cholesterol, VLDL cholesterol, free fatty acids, and serum electrolytes (i.e., sodium, potassium, calcium). Results: There was statistically significant decrease in both systolic blood pressure (SBP) and diastolic blood pressure (DBP) at week 3 and week 6 compared to baseline. The change at week 6 for the SBP was 8.2 mmHg (SD=3.6, P<0.005) and for the DBP was 8.5 mmHG (SD=2.9, P<0.005). Conclusions: The results from this pilot study suggest that celery seed extract may have clinically relevant blood pressure–lowering effects, indicating that additional clinical research is warranted.
Natural Medicine Journal. 2013;4(4):1-3.
Prevalence of hypertension and circadian blood pressure variations in patients with obstructive sleep apnea-hypopnea syndrome.
OBJECTIVE: To investigate the prevalence of hypertension and circadian blood pressure (BP) variations in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: Patients referred to a sleep clinic underwent polysomnography with measurement of BP at four time points. They were classified into four groups (control, and mild, moderate or severe sleep apnea) using the apnea-hypopnea index (AHI). Circadian variation was assessed using night-time to daytime mean BP (R N/D) and morning to evening mean BP (R M/E) ratios. RESULTS: Hypertension was significantly more common in patients with OSAHS (50.5%) than in controls (30.4%). AHI was positively correlated with hypertension after controlling for related confounders. Mean BP values at all four time points rose with increasing AHI. The increase in night-time and morning values was more pronounced than the increase in daytime and evening values in patients with OSAHS, resulting in loss of the normal BP diurnal rhythm. The R N/D and R M/E ratios increased with increasing AHI. Daytime BP was significantly correlated with AHI and the lowest oxygen saturation value. CONCLUSION: OSAHS was shown to be an independent risk factor for hypertension. It was also associated with loss of the normal BP diurnal rhythm.
J Int Med Res . 2014 Mar 20;42(3):773-780.
Olive (Olea europaea) leaf extract effective in patients with stage-1 hypertension: comparison with Captopril.
A double-blind, randomized, parallel and active-controlled clinical study was conducted to evaluate the anti-hypertensive effect as well as the tolerability of Olive leaf extract in comparison with Captopril in patients with stage-1 hypertension. Additionally, this study also investigated the hypolipidemic effects of Olive leaf extract in such patients. It consisted of a run-in period of 4 weeks continued subsequently by an 8-week treatment period. Olive (Olea europaea L.) leaf extract (EFLA(®)943) was given orally at the dose of 500 mg twice daily in a flat-dose manner throughout the 8 weeks. Captopril was given at the dosage regimen of 12.5 mg twice daily at start. After 2 weeks, if necessary, the dose of Captopril would be titrated to 25 mg twice daily, based on subject’s response to treatment. The primary efficacy endpoint was reduction in systolic blood pressure (SBP) from baseline to week-8 of treatment. The secondary efficacy endpoints were SBP as well as diastolic blood pressure (DBP) changes at every time-point evaluation and lipid profile improvement. Evaluation of BP was performed every week for 8 weeks of treatment; while of lipid profile at a 4-week interval. Mean SBP at baseline was 149.3±5.58 mmHg in Olive group and 148.4±5.56 mmHg in Captopril group; and mean DBPs were 93.9±4.51 and 93.8±4.88 mmHg, respectively. After 8 weeks of treatment, both groups experienced a significant reduction of SBP as well as DBP from baseline; while such reductions were not significantly different between groups. Means of SBP reduction from baseline to the end of study were -11.5±8.5 and -13.7±7.6 mmHg in Olive and Captopril groups, respectively; and those of DBP were -4.8±5.5 and -6.4±5.2 mmHg, respectively. A significant reduction of triglyceride level was observed in Olive group, but not in Captopril group. In conclusion, Olive (Olea europaea) leaf extract, at the dosage regimen of 500 mg twice daily, was similarly effective in lowering systolic and diastolic blood pressures in subjects with stage-1 hypertension as Captopril, given at its effective dose of 12.5-25 mg twice daily.
Phytomedicine . 2011 Feb 15;18(4):251-8.
Food supplementation with an olive (Olea europaea L.) leaf extract reduces blood pressure in borderline hypertensive monozygotic twins.
Hypertension is a harmful disease factor that develops unnoticed over time. The treatment of hypertension is aimed at an early diagnosis followed by adequate lifestyle changes rather than pharmacological treatment. The olive leaf extract EFLA943, having antihypertensive actions in rats, was tested as a food supplement in an open study including 40 borderline hypertensive monozygotic twins. Twins of each pair were assigned to different groups receiving 500 or 1,000 mg/day EFLA943 for 8 weeks, or advice on a favourable lifestyle. Body weight, heart rate, blood pressure, glucose and lipids were measured fortnightly. Blood pressure changed significantly within pairs, depending on the dose, with mean systolic differences of < or =6 mmHg (500 mg vs control) and < or =13 mmHg (1000 vs 500 mg), and diastolic differences of < or =5 mmHg. After 8 weeks, mean blood pressure remained unchanged from baseline in controls (systolic/diastolic: 133 +/- 5/77 +/- 6 vs 135 +/- 11/80 +/- 7 mmHg) and the low-dose group (136 +/- 7/77 +/- 7 vs 133 +/- 10/76 +/- 7), but had significantly decreased for the high dose group (137 +/- 10/80 +/- 10 vs 126 +/- 9/76 +/- 6). Cholesterol levels decreased for all treatments with significant dose-dependent within-pair differences for LDL-cholesterol. None of the other parameters showed significant changes or consistent trends. Concluding, the study confirmed the antihypertensive and cholesterol-lowering action of EFLA943 in humans.
Phytother Res. 2008 Sep;22(9):1239-42.
Risk of Breast Cancer Recurrence Associated with Carbohydrate Intake and Tissue Expression of IGFI Receptor.
BACKGROUND: The insulin-like growth factor-I (IGFI) receptor is a potential target for breast cancer treatment and may be influenced by dietary intake. METHODS: Nested, case-control study of 265 postmenopausal breast cancer survivors; primary breast cancer tissue was stained to determine IGFI receptor status. Change in carbohydrate intake from baseline to year 1 of study was estimated from 24-hour dietary recalls. Breast cancer recurrence cases (91) were matched to two controls (n = 174) on disease and study characteristics and counter matched on change in carbohydrate intake. Weighted conditional logistic regression models fit the risk of recurrence on IGFI receptor status and dietary change. RESULTS: Half of the tumors were IGFI receptor positive. Increased risk of recurrence was associated with IGFI receptor-positive status [HR 1.7; 95% confidence interval (CI), 1.2-2.5] and, separately, with a stable/increased intake of carbohydrates (HR 2.0; 95% CI, 1.3-5.0). There was a borderline significant interaction between those two variables (P = 0.11). Specifically, carbohydrate intake had no significant impact on risk of recurrence among women who were receptor negative, yet increased the risk of recurrence by more than 5-fold among women who were receptor positive (HR 5.5; 95% CI, 1.8-16.3). CONCLUSIONS: Among women whose tumor tissue is positive for the IGFI receptor, reducing carbohydrate intake after diagnosis could reduce the risk of breast cancer recurrence. These findings need replication in a larger sample. IMPACT: This is the first study to suggest that it may be possible to personalize dietary recommendations for breast cancer survivors based on molecular characteristics of their primary tumor tissue.
Cancer Epidemiol Biomarkers Prev . 2014 Jul;23(7):1273-9.
Dietary glycemic index and glycemic load and breast cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC).
BACKGROUND: The glycemic potential of a diet is associated with chronically elevated insulin concentrations, which may augment breast cancer (BC) risk by stimulating insulin receptor or by affecting insulin-like growth factor I (IGF-I)-mediated mitogenesis. It is unclear whether this effect differs by BC phenotype. OBJECTIVE: The objective was to investigate the relation between glycemic index (GI), glycemic load (GL), and total carbohydrate intake with BC by using data from the European Prospective Investigation into Cancer and Nutrition (EPIC). DESIGN: We identified 11,576 women with invasive BC among 334,849 EPIC women aged 34-66 y (5th to 95th percentiles) at baseline over a median follow-up of 11.5 y. Dietary GI and GL were calculated from country-specific dietary questionnaires. We used multivariable Cox proportional hazards models to quantify the association between GI, GL, and carbohydrate intake and BC risk. BC tumors were classified by receptor status. RESULTS: Overall GI, GL, and carbohydrates were not related to BC. Among postmenopausal women, GL and carbohydrate intake were significantly associated with an increased risk of estrogen receptor-negative (ER(-)) BC when extreme quintiles (Q) were compared [multivariable HR(Q5-Q1) (95% CI) = 1.36 (1.02, 1.82; P-trend = 0.010) and HR(Q5-Q1) = 1.41 (1.05, 1.89; P-trend = 0.009), respectively]. Further stratification by progesterone receptor (PR) status showed slightly stronger associations with ER(-)/PR(-) BC [HR(Q5-Q1) (95% CI) = 1.48 (1.07, 2.05; P-trend = 0.010) for GL and HR(Q5-Q1) = 1.62 (1.15, 2.30; P-trend = 0.005) for carbohydrates]. No significant association with ER-positive BC was observed. CONCLUSION: Our results indicate that a diet with a high GL and carbohydrate intake is positively associated with an increased risk of developing ER(-) and ER(-)/PR(-) BC among postmenopausal women.
Am J Clin Nutr . 2012 Aug;96(2):345-55.
Insulin-like growth factor I and risk of breast cancer by age and hormone receptor status-A prospective study within the EPIC cohort.
Experimental evidence shows cross-talk in mammary cells between estrogen, insulin-like growth factor
I (IGF-I) and their respective receptors and possible synergistic effects of estrogen receptor (ER) activation and increased IGF-I signaling with regard to
breast tumor development, and epidemiological evidence suggests that circulating IGF-I levels may be related more to the risk of ER-positive than
ER-negative breast cancer. Using a case-control study nested within the prospective European EPIC cohort (938 breast cancer cases and 1,394 matched control
subjects), we analyzed the relationships of prediagnostic serum IGF-I levels with the risk of estrogen and progesterone receptor-positive and -negative
breast tumors. IGF-I levels were positively associated with the risk of ER+ breast tumors overall (pre- and postmenopausal women combined, odds ratio
(OR)Q4-Q1 = 1.41 [95% confidence interval (CI) 1.01-1.98] for the highest vs. lowest quartile; OR = 1.17 [95% CI 1.04-1.33] per 1-standard deviation (SD)
increase in IGF-I, p trend = 0.01) and among women who were diagnosed with breast cancer at 50 years or older (ORQ3-Q1 = 1.38 [95% CI 1.01-1.89]; OR = 1.19
[95% CI 1.04-1.36] per 1-SD increase in IGF-I, p trend = 0.01) but not with receptor-positive disease diagnosed at an earlier age. No statistically
significant associations were observed for ER- breast tumors overall and by age at diagnosis. Tests for heterogeneity by receptor status of the tumor were
not statistically significant, except for women diagnosed with breast cancer at 50 years or older (p het = 0.03 for ER+/PR+ vs. ER-/PR- disease). Our data
add to a global body of evidence indicating that higher circulating IGF-I levels may increase risk specifically of receptor-positive, but not
receptor-negative, breast cancer diagnosed at 50 years or older.
Int J Cancer . 2014 Jun 1;134(11):2683-90.
Over-stimulation of insulin/IGF-1 signaling by western diet may promote diseases of civilization: lessons learnt from laron syndrome.
The insulin/insulin-like growth factor-1 (IGF-1) pathway drives an evolutionarily conserved network that regulates life span and longevity. Individuals with Laron syndrome who carry mutations in the growth hormone receptor (GHR) gene that lead to severe congenital IGF-1 deficiency with decreased insulin/IGF-1 signaling (IIS) exhibit reduced prevalence rates of acne, diabetes and cancer. Western diet with high intake of hyperglycemic carbohydrates and insulinotropic dairy over-stimulates IIS. The reduction of IIS in Laron subjects unmasks the potential role of persistent hyperactive IIS mediated by Western diet in the development of diseases of civilization and offers a rational perspective for dietary adjustments with less insulinotropic diets like the Paleolithic diet.
Nutr Metab (Lond) . 2011 Jun 24;8:41.
IGF-I retards proper development of acinar structures formed by bovine mammary epithelial cells via sustained activation of Akt kinase.
Insulin-like growth factor-I is involved in mammary gland development, promoting proli-feration and inhibiting apoptosis of mammary epithelial cells (MECs). Mitogenic actions of IGF-I are mainly mediated by the phosphatidylinositol-3 kinase (PI3K)/Akt signaling pathway. We have found that in the presence of IGF-I bovine BME-UV1 MECs cultured on reconstituted basement membrane form large spheroids with disrupted polarity and no cavity in the center. These cells showed enhanced phosphorylation of Akt, decreased level of cleaved caspase-3, and sustained proliferative activity throughout the 16-d period of 3-dimensional culture. Inhibition of the PI3K/Akt pathway by a specific inhibitor of PI3K, LY294002, resulted in the restoration of the normal acinar phenotype. However, this effect was noted only when LY294002 was added in the second week of 3-dimensional culture, which corresponded with the time of cell cycle arrest and polarity formation under control conditions. Normal development of acini was also obtained when BME-UV1 cells were treated simultaneously with IGF-I and 17b-estradiol. The addition of 17b-estradiol regulated Akt activation, enabling the subsequent initiation of polarization processes. 17b-Estradiol also increased the level of IGFBP-3 protein in MECs cultured on Matrigel in the presence of IGF-I. The presented results indicate important interactions between signaling pathways activated by estrogen and IGF-I, which regulate alveologenesis in bovine mammary gland.
Domest Anim Endocrinol . 2013 Oct;45(3):111-21.
Ganitumab with either exemestane or fulvestrant for postmenopausal women with advanced, hormone-receptor-positive breast cancer: a randomised, controlled, double-blind, phase 2 trial.
BACKGROUND: Insulin-like growth factors (IGF-1 and IGF-2) bind to the IGF-1 receptor (IGF-1R), increasing cell proliferation and survival. Ganitumab is a monoclonal IgG1 antibody that blocks IGF-1R. We tested the efficacy and safety of adding ganitumab to endocrine treatment for patients with hormone-receptor-positive breast cancer. METHODS: We did this phase 2 trial in outpatient clinics and hospitals. We enrolled postmenopausal women with hormone-receptor-positive, locally advanced or metastatic breast cancer previously treated with endocrine treatment. They were randomly assigned (2:1) with a central randomisation schedule to receive intravenous ganitumab 12 mg per kg bodyweight or placebo in combination with open-label intramuscular fulvestrant (500 mg on day 1, then 250 mg on days 15, 29, and every 28 days) or oral exemestane (25 mg once daily) on a 28-day cycle. Patients, investigators, study monitors, and the sponsor staff were masked to treatment allocation. Response was assessed every 8 weeks. The primary endpoint was median progression-free survival in the intention-to-treat population. We analysed overall survival as one of our secondary endpoints. The study is registered at ClinicalTrials.gov, number NCT00626106. FINDINGS: We screened 189 patients and enrolled 156 (106 in the ganitumab group and 50 in the placebo group). Median progression-free survival did not differ significantly between the ganitumab and placebo groups (3·9 months, 80% CI 3·6-5·3 vs 5·7 months, 4·4-7·4; hazard ratio [HR] 1·17, 80% CI 0·91-1·50; p=0·44). However, overall survival was worse in the the ganitumab group than in the placebo group (HR 1·78, 80% CI 1·27-2·50; p=0·025). With the exception of hyperglycaemia, adverse events were generally similar between groups. The most common grade 3 or higher adverse event was neutropenia-reported by six of 106 (6%) patients in the ganitumab group and one of 49 (2%) in the placebo group. Hyperglycaemia was reported by 12 of 106 (11%) patients in the ganitumab group (with six patients having grade 3 or 4 hyperglycaemia) and none of 49 in the placebo group. Serious adverse events were reported by 27 of 106 (25%) patients in the ganitumab group and nine of 49 (18%) patients in the placebo group. INTERPRETATION: Addition of ganitumab to endocrine treatment in women with previously treated hormone-receptor-positive locally advanced or metastatic breast cancer did not improve outcomes. Our results do not support further study of ganitumab in this subgroup of patients.
Lancet Oncol . 2013 Mar;14(3):228-35.
Effects of Calorie Restriction and IGF-1 Receptor Blockade on the Progression of 22Rv1 Prostate Cancer Xenografts.
Calorie restriction (CR) inhibits prostate cancer progression, partially through modulation of the IGF axis. IGF-1 receptor (IGF-1R) blockade reduces prostate cancer xenograft growth. We hypothesized that combining calorie restriction with IGF-1R blockade would have an additive effect on prostate cancer growth. Severe combined immunodeficient mice were subcutaneously injected with 22Rv1 cells and randomized to: (1) Ad libitum feeding/intraperitoneal saline (Ad-lib); (2) Ad-lib/20 mg/kg twice weekly, intraperitoneal ganitumab [anti-IGF-1R antibody (Ad-lib/Ab)]; (3) 40% calorie restriction/intraperitoneal saline (CR); (4) CR/ intraperitoneal ganitumab, (CR/Ab). CR and ganitumab treatment were initiated one week after tumor injection. Euthanasia occurred 19 days post treatment. Results showed that CR alone decreased final tumor weight, plasma insulin and IGF-1 levels, and increased apoptosis. Ganitumab therapy alone reduced tumor growth but had no effect on final tumor weight. The combination therapy (CR/Ab) further decreased final tumor weight and proliferation, increased apoptosis in comparison to the Ad-lib group, and lowered plasma insulin levels relative to the Ad-lib and Ad-lib/Ab groups. Tumor AKT activation directly correlated with plasma IGF-1 levels. In conclusion, whereas ganitumab therapy modestly affected 22Rv1 tumor growth, combining IGF-1R blockade with calorie restriction resulted in a significant decrease in final tumor weight and improved metabolic profile.
Int J Mol Sci . 2013 Jul 3;14(7):13782-95.
Metformin-mediated growth inhibition involves suppression of the IGF-I receptor signalling pathway in human pancreatic cancer cells.
BACKGROUND: Epidemiol-ogical studies have shown direct associations between type 2 diabetes and obesity, both conditions associated with hyperglycaemia and hyperinsulinemia, and the risk of pancreatic cancer. Up to 80% of pancreatic cancer patients present with either new-onset type 2 diabetes or impaired glucose tolerance at the time of diagnosis. Recent population studies indicate that the incidence of pancreatic cancer is reduced among diabetics taking metformin. In this study, the effects of exposure of pancreatic cancer cells to high glucose levels on their growth and response to metformin were investigated. METHODS: The human pancreatic cancer cell lines AsPC-1, BxPC-3, PANC-1 and MIAPaCa-2 were grown in normal (5 mM) or high (25 mM) glucose conditions, with or without metformin. The influence by metformin on proliferation, apoptosis and the AMPK and IGF-IR signalling pathways were evaluated in vitro. RESULTS: Metformin significantly reduced the proliferation of pancreatic cancer cells under normal glucose conditions. Hyperglycaemia however, protected against the metformin-induced growth inhibition. The anti-proliferative actions of metformin were associated with an activation of AMP-activated protein kinase AMPKThr172 together with an inhibition of the insulin/insulin-like growth factor-I (IGF-I) receptor activation and downstream signalling mediators IRS-1 and phosphorylated Akt. Furthermore, exposure to metformin during normal glucose conditions led to increased apoptosis as measured by poly(ADP-ribose) polymerase (PARP) cleavage. In contrast, exposure to high glucose levels promoted a more robust IGF-I response and Akt activation which correlated to stimulated AMPKSer485 phosphorylation and impaired AMPKThr172 phosphorylation, resulting in reduced anti-proliferative and apoptotic effects by metformin. CONCLUSION: Our results indicate that metformin has direct anti-tumour activities in pancreatic cancer cells involving AMPKThr172 activation and suppression of the insulin/IGF signalling pathways. However, hyperglycaemic conditions enhance the insulin/IGF-I responses resulting in an altered AMPK activation profile and prevent metformin from fully switching off the growth promoting signals in pancreatic cancer cells.
BMC Cancer . 2013 May 10;13:235.
A phase I trial of the IGF-1R antibody Cixutumumab in combination with temsirolimus in patients with metastatic breast cancer.
The mammalian target of rapamycin (mTOR) plays a critical role in promoting tumor cell growth and is frequently activated in breast cancer. In preclinical studies, the antitumor activity of mTOR inhibitors is attenuated by feedback up-regulation of AKT mediated in part by Insulin-like growth factor type 1 receptor (IGF-1R). We designed a phase I trial to determine the maximum-tolerated dose (MTD) and pharmacodynamic effects of the IGF-1R antibody Cixutumumab in combination with temsirolimus in patients with metastatic breast cancer refractory to standard therapies. A 3 + 3 Phase I design was chosen. Temsirolimus and Cixutumumab were administered intravenously on days 1, 8, 15, and 22 of a 4-week cycle. Of the 26 patients enrolled, four did not complete cycle 1 because of disease progression (n = 3) or comorbid condition (n = 1) and were replaced. The MTD was determined from the remaining 22 patients, aged 34-72 (median 48) years. Most patients (86%) had estrogen receptor positive cancer. The median number of prior chemotherapy regimens for metastatic disease was 3. The MTD was determined to be Cixutumumab 4 mg/kg and temsirolimus 15 mg weekly. Dose-limiting toxicities (DLTs) included mucositis, neutropenia, and thrombocytopenia. Other adverse events included grade 1/2 fatigue, anemia, and hyperglycemia. No objective responses were observed, but four patients experienced stable disease that lasted for at least 4 months. Compared with baseline, there was a significant increase in the serum levels of IGF-1 (p < 0.001) and IGFBP-3 (p = 0.019) on day 2. Compared with day 2, there were significant increases in the serum levels of IGF-1 (p < 0.001), IGF-2 (p = 0.001), and IGFBP-3 (p = 0.019) on day 8. A phase II study in women with metastatic breast cancer is ongoing.
Breast Cancer Res Treat . 2013 May;139(1):145-53.
A randomized controlled trial of diet and physical activity in BRCA mutation carriers.
High serum levels of insulin-like growth factor I (IGF-I) are associated with an increased risk of sporadic breast cancer (BC). Furthermore, insulin and markers of insulin resistance, such as abdominal obesity, high blood glucose, high serum testosterone and metabolic syndrome, may affect both BC incidence and prognosis. We hypothesized that all these factors might be relevant also for hereditary BC, due to a deleterious mutation of BRCA genes. Epidemiological observation suggested that weight, energy intake (usually associated with higher bio-availability of growth factors) and physical activity may be relevant in BRCA mutation carriers. Mechanistic studies hypothesized a functional interaction between BRCA genes and the IGF-I system. We have provided some evidence that high serum levels of IGF-I are associated with a significantly increased penetrance. We are recruiting a larger cohort of BRCA mutation carriers in order to test potential modulators of penetrance and prognosis. Within this cohort, we have planned a randomized controlled trial to test whether moderate calorie and protein restriction, together with physical activity, decrease IGF-I. Eligible study subjects are women with or without BC, aged 18-70, with a proven deleterious BRCA mutation, and without metastases. All the women will receive recommendations for the dietary prevention of cancer. The women will be then randomized into an active life-style intervention group and into a control group that will receive only the baseline recommendations. We expect to significantly reduce IGF-I in the intervention group. This trial and the subsequent cohort follow-up might open up primary prevention options for genetic BC.
Fam Cancer . 2014 Jun;13(2):181-7.
Elevated galectin-3 precedes the development of CKD.
Galectin-3, a profibrotic mediator, is linked to the development of renal fibrosis in animal models and inversely correlates with GFR in humans, but whether galectin-3 predicts incident kidney disease is unknown. Here, we assessed renal outcomes for 2450 Framingham Offspring participants who attended examination 6 (1995-1998) and had follow-up data at examination 8 (2005-2008). Renal outcomes of interest included rapid decline in renal function (≥3 ml/min per 1.73 m(2) per year decline in estimated GFR [eGFR]), CKD (eGFR < 60 ml/min per 1.73 m(2)), and albuminuria (albumin-to-creatinine ratio ≥17 mg/g in men or ≥25 mg/g in women). We used multivariable logistic regression models to evaluate associations between galectin-3 with incident renal outcomes at examination 8. During a mean follow-up of 10.1 years, GFR declined rapidly in 241 (9.2%) participants, incident CKD developed in 277 (11.3%), and albuminuria developed in 194 (10.1%). Higher plasma levels of galectin-3 were associated with rapid decline in eGFR (per 1-SD log-galectin-3; adjusted odds ratio [OR], 1.49; 95% confidence interval [CI], 1.28 to 1.73]) and a higher risk of incident CKD (OR, 1.47; 95% CI, 1.27 to 1.71), but not with the risk of incident albuminuria. The addition of galectin-3 to clinical predictors improved the C-statistic (0.837-0.845; P=0.02) but did not reach predefined thresholds for clinically significant improvements to risk prediction based on reclassification indices. In conclusion, elevated levels of plasma galectin-3 are associated with increased risks of rapid GFR decline and of incident CKD in the community, which calls for further study in higher-risk groups.
J Am Soc Nephrol . 2013 Sep;24(9):1470-7.
Galectin-3: a modifiable risk factor in heart failure.
Myocardial galectin-3 is upregulated upon cardiac stressors such as angiotensin II and pressure overload leading to cardiac remodeling and heart failure. The expression level of galectin-3 mirrors the progression and severity of heart failure and therefore, galectin-3 is being used as a biomarker for heart failure. However, as galectin-3 is causally involved in pathological myocardial fibrosis it has been suggested that galectin-3 also actively contributes to heart failure development. In this review we discuss how galectin-3 could be a target for therapy in heart failure. Currently, attempts are being made to target or inhibit galectin-3 using natural or pharmaceutical inhibitors with the aim to ameliorate heart failure. Available experimental evidence suggests that galectin-3 inhibition indeed may represent a novel tool to treat heart failure. A strong interaction with aldosterone, another strong pro-fibrotic factor, has been described. Clinical studies are needed to prove if galectin-3 may be used to install specific treatment regimens.
Cardiovasc Drugs Ther . 2014 Jun;28(3):237-46.
Galectin-3 mediates aldosterone-induced vascular fibrosis.
OBJECTIVE: Aldosterone (Aldo) is involved in arterial stiffness and heart failure, but the mechanisms have remained unclear. Galectin-3 (Gal-3), a b-galactoside-binding lectin, plays an important role in inflammation, fibrosis, and heart failure. We investigated here whether Gal-3 is involved in Aldo-induced vascular fibrosis. METHODS AND RESULTS: In rat vascular smooth muscle cells Gal-3 overexpression enhanced specifically collagen type I synthesis. Moreover Gal-3 inhibition by modified citrus pectin or small interfering RNA blocked Aldo-induced collagen type I synthesis. Rats were treated with Aldo-salt combined with spironolactone or modified citrus pectin for 3 weeks. Hypertensive Aldo-treated rats presented vascular hypertrophy, inflammation, fibrosis, and increased aortic Gal-3 expression. Spironolactone or modified citrus pectin treatment reversed all the above effects. Wild-type and Gal-3 knock-out mice were treated with Aldo for 6 hours or 3 weeks. Aldo increased aortic Gal-3 expression, inflammation, and collagen type I in wild-type mice at both the short- and the long-term, whereas no changes occurred in Gal-3 knock-out mice. CONCLUSIONS: Our data indicate that Gal-3 is required for inflammatory and fibrotic responses to Aldo in vascular smooth muscle cells in vitro and in vivo, suggesting a key role for Gal-3 in vascular fibrosis.
Arterioscler Thromb Vasc Biol . 2013 Jan;33(1):67-75.
Age-specific cancer incidence rates increase through the oldest age groups.
BACKGROUND: In the United States, from 2005 to 2009, nearly 8% of all cancers diagnosed and 15% of cancer deaths occurred in individuals aged 85 years and older (85+ age group). With the aging of the U.S. population, an analysis of incidence of cancer in the elderly population may provide information for clinical care and resource allocation. MATERIALS AND METHODS: Previously reported data were retrieved from the Surveillance Epidemiology and End Results (SEER) 18 Registry for years 2000 to 2010 and Central Brain Tumor Registry of the United States (CBTRUS) for years 2004 to 2008. Cancers included invasive cases only, except for nonmalignant meningiomas, and rates were per 100,000. RESULTS: The age-specific cancer incidence rate (IR) increases with age until a decrease in the 85+ age group. IR for all cancers combined for this age group was 2,317 per 100,000. Statistically, males had significantly higher IR compared with females (3,194 versus 1,911 [P ≤ 0.0001]). Blacks had an IR similar to whites (2,255 versus 2,340 [P = 0.12]). Despite a drop in the overall IR in this oldest age group, IR for certain cancers continued to increase. Among these cancers, gastrointestinal cancers like colorectal, pancreatic and stomach had the highest incidence and mortality rates. CONCLUSIONS: This study contributes to measuring cancer burden in the oldest old population. In certain cancers, including meningiomas, the IR continues to rise with advancing age. Management of cancer in elderly is challenging and screening persons in the 85+ age group for frailty very thoroughly may help guide decisions of palliative versus aggressive therapies.
Am J Med Sci . 2014 Jul;348(1):65-70.
Galectin-3: a possible complementary marker to the PSA blood test.
The prostate-specific antigen (PSA) test has served as a blood marker of prostate cancer (PCa), and for monitoring recurrence/metastasis in patients after therapeutic intervention. However, the applicability/reliability of the PSA test was recently questioned as it is not without challenges, in particular in men who have PCa without an elevated PSA (false negative), or in men who are disease-free with elevated levels of PSA (false positive). Galectin-3 is a tumor-associated protein; present in the seminal fluid and is a substrate for the PSA enzyme e.g., a chymotrypsin-like serine protease. We hypothesized that the cleavage status and level of galectin-3 in the prostate tissue and sera are associated with PCa. Thus, we compared galectin-3 levels obtained from sera of non-cancer urology patients to those of metastatic PCa patients. The data were confirmed by analyzing PCa tissue arrays. Here, we report that galectin-3 levels in the sera of patients with metastatic PCa were uniformly higher as compared to the non-cancer patient controls. The data suggest that galectin-3 serum level may be a useful serum complementary marker to the PSA blood test to be used for initial and follow-up PSA complimentary diagnostic/prognostic tool for recurrence in PCa patients.
Oncotarget . 2013 Apr;4(4):542-9.
Inhibition of prostate cancer bone metastasis by synthetic TF antigen mimic/galectin-3 inhibitor lactulose-L-leucine.
Currently incurable, prostate cancer metastasis has a remarkable ability to spread to the skeleton. Previous studies demonstrated that interactions mediated by the cancer-associated Thomsen-Friedenreich glycoantigen (TF-Ag) and the carbohydrate-binding protein galectin-3 play an important role in several rate-limiting steps of cancer metastasis such as metastatic cell adhesion to bone marrow endothelium, homotypic tumor cell aggregation, and clonogenic survival and growth. This study investigated the ability of a synthetic small-molecular-weight nontoxic carbohydrate-based TF-Ag mimic lactulose-L-leucine (Lac-L-Leu) to inhibit these processes in vitro and, ultimately, prostate cancer bone metastasis in vivo. Using an in vivo mouse model, based on intracardiac injection of human PC-3 prostate carcinoma cells stably expressing luciferase, we investigated the ability of Lac-L-Leu to impede the establishment and growth of bone metastasis. Parallel-flow chamber assay, homotypic aggregation assay, modified Boyden chamber assay, and clonogenic growth assay were used to assess the effects of Lac-L-Leu on tumor cell adhesion to the endothelium, homotypic tumor cell aggregation, transendothelial migration, and clonogenic survival and growth, respectively. We report that daily intraperitoneal administration of Lac-L-Leu resulted in a three-fold (P < .05) decrease in metastatic tumor burden compared with the untreated control. Mechanistically, the effect of Lac-L-Leu, which binds and inhibits galectins by mimicking essential structural features of the TF-Ag, was associated with a dose-dependent inhibition of prostate cancer cell adhesion to bone marrow endothelium, homotypic aggregation, trans-endothelial migration, and clonogenic growth. We conclude that small-molecular-weight carbohydrate-based compounds targeting b-galactoside-mediated interactions could provide valuable means for controlling and preventing metastatic prostate cancer spread to the skeleton.
Neoplasia . 2012 Jan;14(1):65-73.
Combination effect of PectaSol and Doxorubicin on viability, cell cycle arrest and apoptosis in DU-145 and LNCaP prostate cancer cell lines.
The effect of PectaSol on Dox (Doxorubicin) cytotoxicity in terms of apoptosis and cell cycle changes in PCa (prostate cancer) cell lines (DU-145 and LNCaP) has been investigated. Combination of PectaSol and Dox resulted in a viability of 29.4 and 32.6% (P<0.001) in DU-145 and LNCaP cells. The IC values decreased 1.5-fold and 1.3-fold in the DU-145 and LNCaP cells respectively. In the DU-145 cells, combination of PectaSol and Dox resulted in a reduction in p27 gene and protein expression (P<0.001). In LNCaP cells, this combination increased p53, p27 and Bcl-2 expression. Treatment with both drugs in DU-145 cells led to an increase in sub-G1 arrest (54.6% compared with 12.2% in Dox). In LNCaP cells, combination of the drugs led to an increased in G₂/M arrest (61.7% compared with 53.6% in Dox). Based on these findings, progressive cytotoxicity effect of Doxand PectaSol together rapidly induce cell death in DU-145 through apoptosis and in LNCaP cells through cell cycle arrest (G₂/M arrest).
Cell Biol Int. 2012 Jul;36(7):601-10.
Synergistic and additive effects of modified citrus pectin with two polybotanical compounds, in the suppression of invasive behavior of human breast and prostate cancer cells.
AIM: The objective of this study was to evaluate the combined effect of a known galectin-3 inhibitor, PectaSol-C modified citrus pectin (MCP), and 2 novel integrative polybotanical compounds for breast and prostate health, BreastDefend (BD) and ProstaCaid (PC), on invasive behavior in human breast and prostate cancer cells in vitro, respectively. METHODS: The effect of MCP and BD and of MCP and PC on invasiveness was assessed by cell adhesion, cell migration, and cell invasion assays. Secretion of urokinase plasminogen activator (uPA) was determined by Western blot analysis. RESULTS: Although low concentrations of MCP (0.25-1.0 mg/mL) do not suppress cell adhesion of breast or prostate cancer cells, the combination of MCP with BD or PC synergistically inhibits adhesion of these cells. Dose-dependent inhibition of breast and prostate cancer cell migration by MCP (0.25-1.0 mg/mL) is synergistically enhanced by BD (20 µg/mL) and PC (10 µg/mL), respectively. BD or PC did not further inhibit the invasion of breast and prostate cancer cells by MCP; however, the combination of MCP with BD or PC suppressed secretion of uPA from breast and prostate cancer cells, respectively. CONCLUSION: The combination of MCP with BD and of MCP with PC synergistically inhibits the metastatic phenotypes of human breast and prostate cancer cells, respectively. Further studies confirming these observations in animal models of breast and prostate cancer metastasis are warranted.
Integr Cancer Ther. 2013 Mar;12(2):145-52.
Genetic and pharmacological inhibition of galectin-3 prevents cardiac remodeling by interfering with myocardial fibrogenesis.
BACKGROUND: Galectin-3 has been implicated in the development of organ fibrosis. It is unknown whether it is a relevant therapeutic target in cardiac remodeling and heart failure.METHODS AND RESULTS: Galectin-3 knock-out and wild-type mice were subjected to angiotensin II infusion (2.5 µg/kg for 14 days) or transverse aortic constriction for 28 days to provoke cardiac remodeling. The efficacy of the galectin-3 inhibitor N-acetyllactosamine was evaluated in TGR (mREN2)27 (REN2) rats and in wild-type mice with the aim of reversing established cardiac remodeling after transverse aortic constriction. In wild-type mice, angiotensin II and transverse aortic constriction perturbations caused left-ventricular (LV) hypertrophy, decreased fractional shortening, and increased LV end-diastolic pressure and fibrosis (P<0.05 versus control wild type). Galectin-3 knock-out mice also developed LV hypertrophy but without LV dysfunction and fibrosis (P=NS). In REN2 rats, pharmacological inhibition of galectin-3 attenuated LV dysfunction and fibrosis. To elucidate the beneficial effects of galectin-3 inhibition on myocardial fibrogenesis, cultured fibroblasts were treated with galectin-3 in the absence or presence of galectin-3 inhibitor. Inhibition of galectin-3 was associated with a downregulation in collagen production (collagen I and III), collagen processing, cleavage, cross-linking, and deposition. Similar results were observed in REN2 rats. Inhibition of galectin-3 also attenuated the progression of cardiac remodeling in a long-term transverse aortic constriction mouse model. CONCLUSIONS: Genetic disru-ption and pharmacological inhibition of galectin-3 attenuates cardiac fibrosis, LV dysfunction, and subsequent heart failure development. Drugs binding to galectin-3 may be potential therapeutic candidates for the prevention or reversal of heart failure with extensive fibrosis.
Circ Heart Fail . 2013 Jan;6(1):107-17.
Inhibition of galectin-3 reduces atherosclerosis in apolipoprotein E-deficient mice.
Atherosclerosis is a major risk factor for cardiovascular disease (CVD) and stroke. Galectin-3 is a carbohydrate-binding lectin implicated in the pathophysiology of CVD and is highly expressed within atherosclerotic lesions in mice and humans. The object of this present study was to use genetic deletion and pharmacological inhibition in a well-characterized mouse model of atherosclerosis to determine the role of galectin-3 in plaque development. Apolipoprotein-E/galectin-3 knockout mice were generated and fed a high-cholesterol “western” diet. Galectin-3 deletion had no consistent effect on the serum lipid profile but halved atherosclerotic lesion formation in the thoracic aorta (57% reduction), the aortic arch (50% reduction) and the brachiocephalic arteries. The aortic plaques were smaller, with reduced lipid core and less collagen. In apolipoprotein E-deficient (ApoE(-/-)) mice, there was a switch from high inducible nitric oxide expression in early lesions (6 weeks) to arginase-1 expression in later lesions (20 weeks), which was reversed in ApoE(-/-)/gal-3(-/-) mice. Administration of modified citrus pectin, an inhibitor of galectin-3, during the latter stage of the disease reduced plaque volume. We conclude that inhibiting galectin-3 causes decreased atherosclerosis. Strategies to inhibit galectin-3 function may reduce plaque progression and potentially represent a novel therapeutic strategy in the treatment of atherosclerotic disease.
Glycobiology . 2013 Jun;23(6):654-63.
‘The way to a man’s heart is through his gut microbiota’--dietary pro- and prebiotics for the management of cardiovascular risk. The human gut microbiota has been identified as a possible novel CVD risk factor. This review aims to summarise recent insights connecting human gut microbiome activities with CVD and how such activities may be modulated by diet. Aberrant gut microbiota profiles have been associated with obesity, type 1 and type 2 diabetes and non-alcoholic fatty liver disease. Transfer of microbiota from obese animals induces metabolic disease and obesity in germ-free animals. Conversely, transfer of pathogen-free microbiota from lean healthy human donors to patients with metabolic disease can increase insulin sensitivity. Not only are aberrant microbiota profiles associated with metabolic disease, but the flux of metabolites derived from gut microbial metabolism of choline, phosphatidylcholine and l-carnitine has been shown to contribute directly to CVD pathology, providing one explanation for increased disease risk of eating too much red meat. Diet, especially high intake of fermentable fibres and plant polyphenols, appears to regulate microbial activities within the gut, supporting regulatory guidelines encouraging increased consumption of whole-plant foods (fruit, vegetables and whole-grain cereals), and providing the scientific rationale for the design of efficacious prebiotics. Similarly, recent human studies with carefully selected probiotic strains show that ingestion of viable microorganisms with the ability to hydrolyse bile salts can lower blood cholesterol, a recognised risk factor in CVD. Taken together such observations raise the intriguing possibility that gut microbiome modulation by whole-plant foods, probiotics and prebiotics may be at the base of healthy eating pyramids advised by regulatory agencies across the globe. In conclusion, dietary strategies which modulate the gut microbiota or their metabolic activities are emerging as efficacious tools for reducing CVD risk and indicate that indeed, the way to a healthy heart may be through a healthy gut microbiota.
Proc Nutr Soc . 2014 May;73(2):172-85.
Alteration of the intestinal microbiome: fecal microbiota transplant and probiotics for Clostridium difficile and beyond.
Clostridium difficile infection is increasingly common with a high risk of recurrence despite antibiotic treatment. In cases of recurrent C. difficile infection, fecal microbiota transplant (FMT) is a highly effective treatment option promoting the restoration of normal gut microbiota. Furthermore, preliminary uncontrolled evidence demonstrates possible benefit of FMT in the management of some cases of inflammatory bowel disease and chronic constipation. In addition to presenting an overview of FMT, we discuss the role of probiotics, a more common approach to modifying the intestinal microbiome. Probiotics have been utilized broadly for many disease processes, including gastrointestinal, cardiovascular and allergic disease settings, although with limited and inconsistent results. Multiple potential areas for research are also identified.
Expert Rev Gastroenterol Hepatol . 2013 Sep;7(7):615-28.
Cholesterol-lowering efficacy of a microencapsulated bile salt hydrolase-active Lactobacillus reuteri NCIMB 30242 yoghurt formulation in hypercholesterolaemic adults.
Several studies have reported limited or no reduction in serum cholesterol in response to probiotic formulations. Recently, probiotics have shown promise in treating metabolic disease due to improved strain selection and delivery technologies. The aim of the present study was to evaluate the cholesterol-lowering efficacy of a yoghurt formulation containing microencapsulated bile salt hydrolase (BSH)-active Lactobacillus reuteri NCIMB 30242, taken twice per d over 6 weeks, in hypercholesterolaemic adults. A total of 114 subjects completed this double-blind, placebo-controlled, randomised, parallel-arm, multi-centre study. This interventional study included a 2-weekwashout, 2-week run-in and 6-week treatment period. Subjects were randomised toconsume either yoghurts containing microencapsulated L. reuteri NCIMB 30242 or placebo yoghurts. Over the intervention period, subjects consuming yoghurts containing microencapsulated L. reuteri NCIMB 30242 attained significant reductions in LDL-cholesterol (LDL-C) of 8·92 % (P = 0·016), total cholesterol (TC) of 4·81 % (P = 0·031) and non-HDL-cholesterol (HDL-C) of 6·01 % (P = 0·029) over placebo, and a significant absolute change in apoB-100 of - 0·19 mmol/l (P = 0·049). Serum concentrations of TAG and HDL-C were unchanged over the course of the study. Present results show that consumption of microencapsulated BSH-active L. reuteri NCIMB 30242 yoghurt is efficacious and safe for lowering LDL-C, TC, apoB-100 and non-HDL-C in hypercholesterolaemic subjects. The efficacy of microencapsulated BSH-active L. reuteri NCIMB 30242 yoghurts appears to be superior to traditional probiotic therapy and akin to that of other cholesterol-lowering ingredients.
Br J Nutr . 2012 May;107(10):1505-13.
Effect of probiotics on biomarkers of cardiovascular disease: implications for heart-healthy diets.
The objectives of this article are to review clinical trials that have examined the effects of probiotics on low-density lipoprotein cholesterol (LDL-C) and to assess the potential of probiotic intake as a therapeutic lifestyle change (TLC) dietary option. Twenty-six clinical studies and two meta-analyses are reviewed. Significant LDL-C reductions were observed for four probiotic strains: Lactobacillus reuteri NCIMB 30242, Enterococcus faecium, and the combination of Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12. Two synbiotics, L. acidophilus CHO-220 plus inulin and L. acidophilus plus fructo-oligosaccharides, also decreased LDL-C. Of the probiotics examined, L. reuteri NCIMB 30242 was found to best meet TLC dietary requirements by 1) significantly reducing LDL-C and total cholesterol, with robustness similar to that of existing TLC dietary options, 2) improving other coronary heart disease risk factors, such as inflammatory biomarkers, and 3) having “generally recognized as safe” (GRAS) status. Based on these results, the probiotic L. reuteri NCIMB 30242 is a viable candidate both for future TLC dietary studies and as a potential option for inclusion in TLC dietary recommendations.
Nutr Rev . 2014 Jan;72(1):18-29.
Cholesterol lowering with bile salt hydrolase-active probiotic bacteria, mechanism of action, clinical evidence, and future direction for heart health applications
Introduction: Cardio-vascular diseases (CVD) are the leading cause of global mortality and morbidity. Current CVD treatment methods include dietary intervention, statins, fibrates, niacin, cholesterol absorption inhibitors, and bile acid sequestrants. These formulations have limitations and, thus, additional treatment modalities are needed. Probiotic bacteria, especially bile salt hydrolase (BSH)-active probiotic bacteria, have demonstrated cholesterol-lowering efficacy in randomized controlled trials. Areas covered: This review describes the current treatments for CVD and the need for additional therapeutics. Gut microbiota etiology of CVD, cholesterol metabolism, and the role of probiotic formulations as therapeutics for the treatment and prevention of CVD are described. Specifically, we review studies using BSH-active bacteria as cholesterol-lowering agents with emphasis on their cholesterol-lowering mechanisms of action. Potential limitations and future directions are also highlighted. Expert opinion: Numerous clinical studies have concluded that BSH-active probiotic bacteria, or products containing them, are efficient in lowering total and low-density lipoprotein cholesterol. However, the mechanisms of action of BSH-active probiotic bacteria need to be further supported. There is also the need for a meta-analysis to provide better information regarding the therapeutic use of BSH-active probiotic bacteria. The future of BSH-active probiotic bacteria most likely lies as a combination therapy with already existing treatment options.
Expert Opinion on Biological Therapy . 2013 May;13(5):631-42.
Gut microbiota regulates bile acid metabolism by reducing the levels of tauro-beta-muricholic acid, a naturally occurring FXR antagonist.
Bile acids are synthesized from cholesterol in the liver and further metabolized by the gut microbiota into secondary bile acids. Bile acid synthesis is under negative feedback control through activation of the nuclear receptor farnesoid X receptor (FXR) in the ileum and liver. Here we profiled the bile acid composition throughout the enterohepatic system in germ-free (GF) and conventionally raised (CONV-R) mice. We confirmed a dramatic reduction in muricholic acid, but not cholic acid, levels in CONV-R mice. Rederivation of Fxr-deficient mice as GF demonstrated that the gut microbiota regulated expression of fibroblast growth factor 15 in the ileum and cholesterol 7a-hydroxylase (CYP7A1) in the liver by FXR-dependent mechanisms. Importantly, we identified tauro-conjugated beta- and alpha-muricholic acids as FXR antagonists. These studies suggest that the gut microbiota not only regulates secondary bile acid metabolism but also inhibits bile acid synthesis in the liver by alleviating FXR inhibition in the ileum.
Cell Metab . 2013 Feb 5;17(2):225-35.
Efflux of bile acids in Lactobacillus reuteri is mediated by ATP.
PURPOSE OF WORK: To study whether an active bile acid (BA) efflux occurs in Lactobacillus reuteri CRL 1098 as well as the nature (ATP or proton motive force [PMF] mediated primary transport) of the BA extrusion mechanism. BAs are powerful detergents which disorganize the lipid bilayer structure of cellular membranes. Specific bile resistance mechanisms (bile efflux, bile salt hydrolysis, and intrinsic architecture and composition of cell membrane the most prevalent) have been described in intestinal bacteria. L. reuteri, showed a significant degree of resistance to the toxic action of BA and the presence of an active efflux ATP-dependent of conjugated (taurocholic [TCA]) and free (cholic [CA]) BA in the CRL 1098 strain is now reported. However, due the high pKa (5.5) of cholic acid (CA) compared with the conjugated species, a significant fraction (between 35 and 50% at pH 6.5 and 5.2, respectively) of free BA also diffused passively, even in the absence of ATP. To our knowledge, our results represent the first evidence of ATP as the energy source involved in the BA extrusion in L. reuteri.
Biotechnol Lett . 2011 Nov;33(11):2265-9.
Improvement of gastrointestinal health status in subjects consuming Lactobacillus reuteri NCIMB 30242 capsules: a post-hoc analysis of a randomized controlled trial
Objective: Gastrointestinal (GI) symptoms are conditions that are frequently observed in clinical practice. A post-hoc analysis has been undertaken to evaluate the effect of bile salt hydrolase-active L. reuteri NCIMB 30242 on GI health status based on Rome III questionnaire response in otherwise healthy hypercholesterolemic subjects. Research design/Methods: A total of 127 subjects received either L. reuteri NCIMB 30242 or placebo capsules over a 9-week intervention in a randomized, double-blind, placebo-controlled, parallel-arm, multicenter study. Subjects were asked to complete the Rome III diagnostic GI questionnaire prior to the baseline and end point visits of the clinical study. Main outcome measure: GI health status was evaluated, per questionnaire, by assessing all questions with 5- or 7-point response scales for symptoms of the stomach and intestines. Results: Subjects receiving L. reuteri NCIMB 30242 reported significant improvements in general GI health status (p = 0.029) and in symptoms related to diarrhea (p = 0.018) as compared to placebo over the intervention period. Further, a greater proportion of L. reuteri-treated subjects showed improved general GI health status (p = 0.042) and improved diarrhea symptoms (p = 0.03). Conclusions: L. reuteri NCIMB 30242 capsules appear to be well tolerated and potentially beneficial for GI health status. Further clinical investigation is warranted for the treatment of functional GI disorders.
Expert Opinion on Biological Therapy . 2013 Dec;13(12):1643-51.
Evaluation of clinical safety and tolerance of a Lactobacillus reuteri NCIMB 30242 supplement capsule: a randomized control trial.
A significant number of human clinical trials have reported no adverse effects associated with consumption of Lactobacillus reuteri (L. reuteri). In the present study, the clinical safety and toxicology of oral ingestion of supplement capsules containing L. reuteri NCIMB 30242 was investigated. A randomized group of 131 subjects received a dose of 2.9×10⁹ CFU L. reuteri NCIMB 30242 capsules (n=67) or placebo capsules (n=64) twice daily for 9 weeks. Clinical chemistry and hematological parameters of safety were analyzed. The frequency, duration and intensity of adverse events (AE)s and clinical significance of safety parameters were recorded for both groups. No clinically significant differences between the probiotic capsule and placebo capsule treated groups were detected in either the blood clinical chemistry or hematology results. The frequency and intensity of AEs was similar in the two groups. These results demonstrate that administration of a twice daily dose of 2.9×10⁹ CFU was safe and well tolerated in the population evaluated over 9 weeks.
Regul Toxicol Pharmacol . 2012 Jul;63(2):313-20.
Oral supplementation with probiotic L. reuteri NCIMB 30242 increases mean circulating 25-hydroxyvitamin D: a post hoc analysis of a randomized controlled trial.
CONTEXT: Low serum 25-hydroxyvitamin D is a risk factor for osteoporosis, cardiovascular disease, diabetes, and cancer. Disruption of noncholesterol sterol absorption due to cholesterol-lowering therapies may result in reduced fat-soluble vitamin absorption. OBJECTIVE: We have previously reported on the cholesterol-lowering efficacy and reduced sterol absorption of probiotic bile salt hydrolase active Lactobacillus reuteri NCIMB 30242; however, the effects on fat-soluble vitamins was previously unknown and the objective of the present study. DESIGN, SETTINGS, PATIENTS, AND, INTERVENTION: The study was double-blind, placebo-controlled, randomized, parallel-arm, multicenter lasting 13 weeks. A total of 127 otherwise healthy hypercholesterolemic adults with low-density lipoprotein-cholesterol >3.4 mmol/L, triglycerides <4.0 mmol/L, and body mass index of 22 to 32 kg/m² were included. Subjects were recruited from 6 private practices in Prague, Czech Republic, and randomized to consume L. reuteri NCIMB 30242 or placebo capsules over a 9-week intervention period. OUTCOME MEASURES: The primary outcome measure was the change in serum low-density lipoprotein-cholesterol over the 9-week intervention. Analysis of fat-soluble vitamins at weeks 0 and 9 were performed post hoc. RESULTS: There were no significant differences between L. reuteri NCIMB 30242 and placebo capsule groups in serum vitamin A, vitamin E, or b-carotene or dietary intake over the intervention period (P > .05). L. reuteri NCIMB 30242 increased serum 25-hydroxyvitamin D by 14.9 nmol/L, or 25.5%, over the intervention period, which was a significant mean change relative to placebo of 17.1 nmol/L, or 22.4%, respectively (P = .003). CONCLUSIONS: To our knowledge, this is the first report of increased circulating 25-hydroxyvitamin D in response to oral probiotic supplementation.
J Clin Endocrinol Metab . 2013 Jul;98(7):2944-51.