Background: cholestasis is a prevalent health problem associated with liver oxidative stress, inflammation, and fibrosis. Quercetin has been shown to afford a beneficial effect in a variety of liver diseases. This study was designed to investigate the potential protective effect of quercetin on liver cholestasis and the possible underlying mechanisms in a rat model of bile duct ligation (BDL). Methods: This study was carried out on adult male rats which were randomly divided into: Sham-operated, BDL and BDL-quercetin treated (BDL-Q) groups. Quercetin was given by gavage in a dose of 50 mg/kg/day. Results: Bile duct ligation resulted in a significant increase in serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and liver levels of myeloperoxidase (MPO), tumor necrosis factor alpha (TNF-α),and transforming growth factor beta 1(TGF-β1), along with a significant decrease in serum levels of total proteins (TPs) and liver glutathione peroxidase(GPX) in BDL group versus sham-operated controls. Quercetin treatment significantly lowered serum levels of AST, ALT, ALP, and MPO, TNF-α, and TGF-β1 in liver tissues associated with a significant increase in serum TPs and liver GPX in BDL-Q group versus BDL rats. Histological studies revealed enhancement of inflammation and a significant increase in the percentage area of collagen deposition in BDL versus sham-operated group. These changes were attenuated in BDL-Q group compared to BDL rats. Conclusions: Quercetin alleviated cholestasis induced liver injury and improved liver function possibly via attenuating liver oxidative stress, inflammation and fibrosis.

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Background: Oxidative stress and inflammation are primarily implicated in the development and progression of liver injury during cholestasis. Selenium, a known essential antioxidant trace element, was found to provide a remarkable antioxidant and anti-inflammatory effects on various diseases. Aim: This study was planned to evaluate the possible protective effect of selenium supplementation in a rat model of chronic cholestasis. Design: Experimental study. Methods: This study was carried out on adult male rats allocated randomly into sham, 4 weeks bile duct ligated (BDL), and BDLselenium treated (BDL-Se) groups. Sodium selenite was given by gavage daily, in a dose of 100 µg/kg for 6 weeks, starting 2 weeks before the BDL. Results: BDL group presented a significant increase in serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and liver levels of malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), and transforming growth factor beta 1(TGF-β1), associated with a significant decrease in serum levels of total proteins (TP) compared to sham group . Selenium supplementation significantly lowered serum levels of AST, ALT, ALP, and liver levels of MDA, TNF-α, and TGF-β1, along with a significant increase in serum TP in BDL-Se group versus BDL rats. Histological analysis of liver showed a significant attenuation of the inflammatory score and a significant decrease in the percentage area of collagen deposition in BDL-Se group versus BDL rats. Conclusion: Selenium supplementation reduces liver injury and improves liver functions in experimental cholestasis probably by its antioxidant and antiinflammatory activities, which further alleviate the liver fibrosis.