Protective effects of monoammonium glycyrrhizinate on fatty deposit degeneration induced in primary calf hepatocytes by sodium oleate administration in vitro

Abstract

In this study we investigated the effect of MAG on fatty deposit-induced degeneration of primary calf hepatocytes induced by sodium oleate. Primary hepatocytes were isolated from dairy calves and cultured before allocation to the following treatment groups: control (untreated), model (starved for 12 h before treatment with 0.25 mM sodium oleate to induce steatosis-like changes, and the MAG group pretreated with MAG (0.1, 0.25, 0.5, and 1.5 mM) for 12 h before sodium oleate treatment (0.25 mM) for 12 h). To evaluate the effect of MAG on fat-induced degradation of primary hepatocytes, we evaluated lipid deposition, cell viability, apoptosis rate, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity in the culture supernatant, and expression of oxidant and antioxidant enzymes (LDH, MDA, GSH, and CAT), as well as the expression of lipid metabolism-related genes (PPARα, SREBP-1c, ChREBP, CPT1, CPT2, and MTP) and apoptosis-related genes (Cyt-c, Caspase 9, Caspase 8, Caspase 3, Bax, and Bcl-2). MAG significantly reduced lipid accumulation in hepatocytes induced by sodium oleate (P < 0.05), increased cell viability, decreased the apoptosis rate (P < 0.05), and significantly decreased ALT and AST activity in the culture supernatant (P < 0.05). MAG significantly decreased MDA levels in cells and LDH levels in the culture supernatant, while GSH and CAT levels were increased (P < 0.05). MAG significantly increased the expression of the lipid transport- and metabolism-related genes MTP, PPARα, CPT1 and CPT2, and decreased ChREBP expression (P < 0.05). At concentrations higher than 0.25 mM, MAG significantly decreased SREBP-1c expression (P < 0.05). MAG significantly decreased the expression of the apoptosis-related genes Cyt-c, Caspase 9, Caspase 8, Caspase3 and Bax, while Bcl-2 expression was increased (P < 0.05). These findings demonstrate that MAG improves the antioxidant capacity of hepatocytes and effectively reduces lipid deposition by inhibiting the expression of lipid metabolism- and apoptosis-related genes.