The antioxidant effect of green tea catechin ameliorates experimental liver injury

Abstract Purpose Several studies have reported green tea catechin to have both antifibrotic and anti-oxidative effects. The goal of this study was to evaluate the effect of green tea cathechin therapy in hepatic tissue injury using cholestatic rats with bile duct ligation. Materials and methods We performed bile duct ligation on cholestatic seven-week-old male Wistar rats and classified them into three groups according to the method of treatment. The groups comprised the SHAM group, the NT-group (no-treatment-group), and the T-group (treatment-group). The rats were orally administered green tea catechin at a dose of 50 mg/kg/day and were sacrificed on the 17th postoperative day. We subsequently investigated the levels of fibrosis and antioxidant activity associated with various clinical markers. We evaluated the serum AST and ALT levels and performed immunohistochemical analyses for 4-hydroxynonenal (4-HNE), 8-oxo-2′deoxyguanosine (8-OHdG) and transforming growth factor-β1 (TGF-β1). We also evaluated the levels of activator protein-1 m-RNA (AP-1 m-RNA) and tissue inhibitor metalloproteinase-1 m-RNA (TIMP-1 m-RNA) by Real Time PCR. Finally, we performed Azan staining and immunohistochemical staining of α-smooth muscle actin (α‐SMA) to evaluate the degree of fibrosis. Results The values of serum AST, serum ALT, AP-1 m-RNA, α‐SMA, TGF-β1, 4-HNE, and 8-OHdG in the T-Group were significantly lower than those in NT-Group. Therefore, the administration of green tea catechin might have suppressed the oxidative stress, controlled the stellate cell activation and consequently reduced the fibrosis. Conclusion Green tea catechin may reduce hepatic fibrosis by suppressing oxidative stress and controlling the transcription factor expression involved in stellate cell activation.