Effects of probiotic Lactobacillus paracasei TD3 on moderation of cholesterol biosynthesis pathway in rats

Prevalence of high-fat food consumption, such as fast foods is one of the major causes of hypercholesterolemia, which can lead to cardiovascular diseases. 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) and cytochrome P450 7A1 (CYP7A1) are two key genes in cholesterol metabolism. Use of probiotics in the diet is a promising approach for modulation of serum lipid. To confirm the modulation of serum lipids by probiotics, in this study, we have examined the efficacy of Lactobacillus paracasei TD3 in improving blood cholesterol levels. 21 male Wistar rats were divided into three groups randomly (n=7). G1: negative control with normal diet, G2: positive control with high-fat diet, G3T: test group with high-fat diet plus supplementation with L. paracasei TD3 (1010 CFU). In the 21st day, the rats were anesthetized using chloroform and then sacrificed. Blood samples were collected to analyze lipid panel parameters and hepatic enzymes by the auto-analyzer system. Adipose tissue samples were analyzed using real-time PCR for HMGCR and CYP7A1 genes expression. Consumption of L. paracasei TD3 could reduce serum cholesterol levels significantly (P<0.05); whereas, there was no significant difference between experimental groups for triglycerides, LDL, and HDL levels. Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) enzymes were significantly decreased in the probiotic group. Furthermore, expression of HMGCR and CYP7A1 genes was dramatically declined in the probiotic group. There was no significant change in either uric acid or urea between the control and treated groups. Introduction of L. paracasei TD3 in rat’s diet can modulate serum cholesterol levels.