Green Tea Catechins Effectively Altered Hepatic Fibrogenesis in Rats by Inhibiting ERK and Smad1/2 Phosphorylation.

Polyphenols derived from green tea have been reported to have a wide range of profound functions. Tea catechins, including epicatechin (EC), epigallocatechin (EGC), epicatechin-3-O-gallate (ECG) and epigallocatechin-3-O-gallate (EGCG), are considered as the major bioactive polyphenols in tea. The present study was designed to elucidate the potential antifibrogenic role of three abundant tea catechins (ECG, EGC, EGCG) in CCl4-induced fibrotic rat and its underlying molecular mechanisms. Tea catechins, especially groups of ECG, EGC and EGCG, effectively induced several beneficial alterations of liver injury markers, oxidative status and liver histology. Furthermore, catechins ameliorated liver fibrosis as evidenced by the reduced expression of desmin, α-smooth muscle actin (α-SMA), transforming growth factor-β (TGF-β), and downstream ERK1/2 and Smad1/2 phosphorylation. The most significant inhibitory effect on those proteins was observed in ECG (300 mg/kg) and EGCG (300 mg/kg) groups. In addition, catechins conferred their protective role by down-regulating the proinflammation cytokines TGF-β, TNF-α and IL-17. It is postulated that tea catechins, particularly ECG and EGCG, are potential therapeutic candidates in antifibrotic therapy.