Ethanol-Induced Hepatotoxicity and Alcohol Metabolism Regulation by GABA-Enriched Fermented Smilax china Root Extract in Rats

Abstract

Chronic alcohol consumption can cause hepatic injury and alcohol-induced toxicities. Extracts from Smilax china root have been widely used in traditional medicine and for their potential pharmacological benefits. We aimed to determine if fermented Smilax china extract (FSC) regulates alcoholic fatty liver and liver injury using two in vivo experiments. Sprague-Dawley rats were administered ethanol (3 g/kg b.w.; po) with or without FSC pretreatment to induce an acute hangover. In another experiment, rats were fed either a normal or Lieber-DeCarli ethanol (6.7%) diet with or without FSC pretreatment (125, 250, and 500 mg/kg b.w.; po) for 28 days. Serum biomarkers, liver histopathology, and the mRNA levels of anti-inflammatory, antioxidant, lipogenic, and lipolytic genes were analyzed. FSC pretreatment significantly reduced blood alcohol and acetaldehyde concentrations, upregulated the mRNA expression of alcohol dehydrogenase, aldehyde dehydrogenase, and superoxide dismutase, and decreased the activities of liver enzymes in a dose-dependent manner. It also downregulated SERBP-1c and upregulated PPAR-α and reduced the gene expression of the anti-inflammatory cytokine IL-6 in the liver. The final extract after fermentation had increased GABA content. Furthermore, FSC was found to be safe with no acute oral toxicity in female rats. Thus, FSC increases alcohol metabolism and exhibits antioxidant and anti-inflammatory effects to induce hepatoprotection against alcohol-induced damage. It may be used as a functional food ingredient after excess alcohol consumption.