Flavonoid constituents and protective efficacy of Citrus reticulate (Blanco) leaves ethanolic extract on thioacetamide-induced liver injury rats

Abstract

Context: Oxidative stress leads to deleterious processes in the liver that resulted in liver diseases. Objective: To evaluate antioxidant activity and hepatoprotective potential of ethanolic leaves extract of Citrus reticulate against hepatic dysfunction induced by thioacetamide (TAA). Materials and Methods: Flavonoid constituents were isolated from the ethanol extract by chromatographic techniques and identified by the spectroscopic analyses. Antioxidant activity was determined using DPPH assay. Hepatotoxicity was induced in rats via intraperitoneal injection of TAA and the ethanol extract was orally administrated at a dose of 100 mg/kg/day for four weeks. Serum biomarkers, hepatic antioxidant enzymes, tumour necrosis factor-alpha (TNF-α), hepatic hydroxyproline levels, and histopathology were examined. Results: Ten known flavonoids were identified, among of them, 6,3`-dimethoxyluteolin and 8,3`-dimethoxyluteolin possessed the highest antioxidant activity. The substantially elevated serum enzymatic levels of ALT, ALP, and bilirubin were found to be restored towards normalisation significantly by the plant extract. Furthermore, the markers including MDA, GSH, SOD, NO, and protein carbonyl which were close to oxidative damage, were restored. Meanwhile, the extract treatment decreased TNF-α level and also was able to reverse the induced fibrosis by significantly reducing the hydroxyproline content. Moreover, histopathological studies further substantiate the protective effect of the extract. Conclusion: C. reticulate leaves extract is a rich source of phytochemicals with in vitro and in vivo protective effects.