METHODOLOGY/PRINCIPAL FINDINGS: The in vitro study demonstrated that T. indica fruit pulp had significant amount of phenolic (244.9 ± 10.1 mg GAE/extract) and flavonoid (93.9 ± 2.6 mg RE/g extract) content and possessed antioxidant activities. In the in vivo study, hamsters fed with high-cholesterol diet for ten weeks showed elevated serum triglyceride, total cholesterol, HDL-C and LDL-C levels. Administration of T. indica fruit pulp to hypercholesterolaemic hamsters significantly lowered serum triglyceride, total cholesterol and LDL-C levels but had no effect on the HDL-C level. The lipid-lowering effect was accompanied with significant increase in the expression of Apo A1, Abcg5 and LDL receptor genes and significant decrease in the expression of HMG-CoA reductase and Mtp genes. Administration of T. indica fruit pulp to hypercholesterolaemic hamsters also protected against oxidative damage by increasing hepatic antioxidant enzymes, antioxidant activities and preventing hepatic lipid peroxidation.
CONCLUSION/SIGNIFICANCE: It is postulated that tamarind fruit pulp exerts its hypocholesterolaemic effect by increasing cholesterol efflux, enhancing LDL-C uptake and clearance, suppressing triglyceride accumulation and inhibiting cholesterol biosynthesis. T. indica fruit pulp has potential antioxidative effects and is potentially protective against diet-induced hypercholesterolaemia.
METHODS AND RESULTS: Lactic acid bacteria strains were isolated and examined for acid tolerance, bile salt resistance and hypocholesterolemic properties. Among the isolates, Lactobacillus plantarum TAR4 showed the highest cholesterol reduction ability (48·01%). The focus in the in vivo trial was to elucidate the cholesterol balance from findings pertaining to serum cholesterol reduction in rat model fed with high fat diet via oral administration. Rats fed with high-cholesterol diet supplemented with Lact. plantarum TAR4 showed significant reduction in serum total cholesterol (29·55%), serum triglyceride (45·31%) and liver triglyceride (23·44%) as compared to high-cholesterol diet (HCD) group. There was a significant increment in faecal triglyceride (45·83%) and faecal total bile acid (384·95%) as compared to HCD group.
CONCLUSIONS: The findings showed that probiotic Lact. plantarum TAR4 supplementation reduced the absorption of bile acids for enterohepatic recycling and increased the catabolism of cholesterol to bile acids and not by suppressing the rate of cholesterol synthesis.
SIGNIFICANCE AND IMPACT OF STUDY: Probiotic supplements could provide a new nonpharmacological alternative to reduce cardiovascular risk factors.