Curative role of lactulose, L-carnitine, alpha-lipoic acid and combination of L-carnitine and alpha-lipoic acid in a rat model of acute hepatic encephalopathy: Biochemical observations

Purpose: To determine whether a combination L-carnitine and a-lipoic acid (ALA) can alleviate the toxic effects of thioacetamide (TAA) via their potent antioxidant and free radical-scavenging activities. Methods: Rats were injected with TAA for 3 days to induce acute hepatic failure. TAA induced rats were treated with each of lactulose, L-carnitine and ALA alone and a combination of L-carnitine and ALA for 3 months. Thereafter, biochemical indices, ammonia levels, oxidative stress markers, and the levels of inflammatory markers were assessed in serum, liver and brain. Results: A significant improvement was observed after 3 months of antioxidants treatment. Lactulose, L-carnitine and ALA significantly decreased serum concentrations of alanine transaminase (ALT), aspartate aminotransaminase (AST) and level of total bilirubin while both levels of total protein (TP) and albumin (ALB) were significantly increased (p < 0.05) compared to TAA group. In addition, each of antioxidants alone significantly decreased ammonia (NH3) concentrations of serum, liver and brain in TAA-induced rats. Treatment with antioxidants for 3 months significantly (p < 0.05) decreased Malondialdehyde (MDA) and nitric oxide (NO) while antioxidant enzyme activities of glutathione peroxidase (GPX) and superoxide dismutase (SOD) were significantly increased (p < 0.05) in liver and brain tissues. The expressions of serum tumor necrosis factor-alpha (TNF-alpha) and soluble protein (S100-beta) were significantly (p < 0.05) down-regulated in TAA-induced rats. Conclusion: L-carnitine in combination with ALA can mitigate HE induced experimentally in rats. The protective efficacy of L-carnitine in combination with ALA in HE can be attributed to suppression of oxidative stress, ammonia concentration and the levels of inflammatory markers. Thus, it may have the potential to be used to treat liver cirrhosis in clinical settings.