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.
MATERIALS AND METHODS: This cross-sectional study included 150 subjects aged 30 years and above who attended a health screening in a Malaysian tertiary institution. Sociodemographics, clinical characteristics and laboratory parameters (lipids, glucose, and sdLDL) were obtained. Lipoprotein subfraction was analysed using the polyacrylamide gel electrophoresis method.
RESULTS: Malays and females made up the majority of subjects and the median age was 37 years. Normolipidaemic Pattern B was significantly higher in women (p=0.008). Significant independent predictors of Pattern B were gender (p=0.02), race (p=0.01), body mass index (BMI) [p=0.02] and lipid status (p=0.01). Triglyceride was the only independent predictor of sdLDL (p=0.001).
CONCLUSION: The prevalence of Pattern B of 33% in this study was comparatively high, of which 6.7% were normolipidaemic. Chinese males with dyslipidaemia and increased BMI independently predicted Pattern B. Differences in triglyceride levels alone among these ethnic groups do not fully explain the differences in the prevalence of Pattern B although it was the only lipid parameter to independently predict sdLDL. Individuals with atherogenic normolipidaemia are at greater risk for a CVD event as they are not included in the protective measures of primary CVD prevention.
METHODS: HepG2 cells were treated with different concentrations of KMF and 0.5 mM palmitate (PA) for 24 h. The mRNA and protein levels of genes involved in lipid metabolism were evaluated using real-time PCR and western blot. The expression of Nrf2 was silenced using siRNA.
RESULTS: Data indicated that KMF (20 μM) reversed PA-induced increased triglyceride (TG) levels and total lipid content. These effects were accompanied by down-regulation of the mRNA and protein levels of lipogenic genes (FAS, ACC and SREBP1), and up-regulation of genes related to fatty acid oxidation (CPT-1, HADHα and PPARα). Kaempferol significantly decreased the levels of the oxidative stress markers (ROS and MDA) and enhanced the activities of antioxidant enzymes SOD and GPx in PA-challenged cells. Luciferase analysis showed that KMF increased the transactivation of Nrf2 in hepatocytes. The results also revealed that KMF-mediated activation of Nrf2 target genes was suppressed by Nrf2 siRNA. Furthermore, Nrf2 siRNA abolished the KMF-induced reduction in ROS and MDA levels in PA treated cells. In addition, the inhibitory effect of KMF on TG levels and the mRNA and protein levels of FAS, ACC and SREPB-1 were significantly abolished by Nrf2 inhibition. Nrf2 inhibition also suppressed the KMF-induced activation of genes involved in β oxidation (CPT-1 and PPAR-α).
CONCLUSION: The results suggest that KMF protects HepG2 cells from PA-induced lipid accumulation via activation of the Nrf2 signaling pathway.