Polyphenol-rich extract from loquat fruit peel prevents hyperlipidemia and hepato-nephrotoxicity in mice: in vivo study and in silico prediction of possible mechanisms involving identified polyphenols and/or their circulating metabolites

Hyperlipidemia is the most well-known cause of metabolic complications and tissue toxicity such as liver steatosis, atherosclerosis and obesity. This study aims to evaluate the preventive effect of loquat fruit peel extract (PE) against tyloxapol-induced hyperlipidemia and related tissue lipotoxicity in mice. The in vivo study was conducted on mice injected daily with tyloxapol at 100 mg per kg B.W. and treated simultaneously with the PE at concentrations of 100 and 200 mg kg-1 or fenofibrate for 28 days. Plasma and tissue lipid biochemical analyses were undertaken using enzymatic methods. The antioxidative stress was revealed by measuring the malondialdehyde content and activities of superoxide dismutase and catalase as well as the scavenging activity against lipoperoxyl radicals. The PE significantly prevented oxidative stress and restored lipid metabolism, plasma glucose, body weight, organ relative mass and biomarkers of hepato-nephrotoxicity as well as the histological structure of the liver and kidneys. It contains five major polyphenols, namely, ferulic acid, caffeic acid, neochlorogenic acid, chlorogenic acid and quercetin. According to molecular docking analysis, these compounds and their circulating metabolites could interact with major proteins implicated in lipid metabolism and oxidative stress. Overall, the study suggests that PE could prevent hyperlipidemia and related toxic tissue complications.