Description
In previous in vitro study, we reported potential mechanism of cholesterol-lowering effect of Lactobacillus brevis119-2 (119-2) isolated from turnip Tsuda kabu is due to incorporation of cholesterol into 119-2 cell. In this study, we analyzed serum cholesterol and hepatic gene expression of Sprague-Dawley (SD) rat fed diet containing cholesterol with or without 119-2 for 2 weeks, to evaluate the cholesterol-lowering effect of 119-2 in vivo. Serum cholesterol of SD rat fed diet with 119-2 significantly decreased compared to SD rat fed diet without 119-2, and both viable and dead 119-2 indicated the effect. The result of hepatic gene analysis using DNA microarray suggested that potential mechanism of the cholesterol-lowering effect of 119-2 in vivo is inhibiting the activity of 3-hydroxy-3-methylglutaryl-CoA reductase by Insig (insulin induced gene) that is endoplasmic reticulum membrane protein, and catabolizing cholesterol to bile acid by Cyp7a1 (cytochrome P450 a1) that is the rate-limiting enzyme in the synthesis of bile acid from cholesterol. In addition, we concluded feeding 119-2 decreased serum low density lipoprotein (LDL) cholesterol by overexpression of Ldlr (LDL receptor gene). On the other hand, feeding Lactobacillus acidophilus ATCC43121 (ATCC) increased high density lipoprotein (HDL) cholesterol by over expression of Abca1 (ATP binding cassette sub-family A member 1 gene) and Angplt3 (Angiopoietin-like 3). These results suggested that 119-2 decrease the risk of atherosclerosis by serum cholesterol-lowering effect and improving effect of fatty liver and the LH (LDL cholesterol / HDL cholesterol) ratio.