Effect of Gallic Acid on Regression of Murine CCL4-Induced Hepatic Cirrhosis

Abstract

Hepatic cirrhosis can be induced by chronic exposure to reactive oxygen species (ROS). However, phenolic compounds, such as gallic acid (GA), appear to inhibit ROS-induced oxidative stress. We aimed to investigate the effects of GA on murine hepatic fibrogenesis. The effects of GA were evaluated on the regression of liver cirrhosis that was induced by chronic intraperitoneal CCl4 administration (20% v/v) in C57 mice for a period of 10 weeks. The animals were treated intraperitoneally and distributed in three groups, as follows: SHAM group – 8 weeks with Olive oil (CCL4 solution vehicle); C group – 8 weeks with CCL4 solution, and then 2 more weeks with deionized water (Gallic Acid solution vehicle); and C + GA group – 8 weeks with CCL4 solution, and then 2 more weeks with Gallic Acid solution (100 mg/Kg/day) on alternated days. The cirrhosis and inflammation-related factors were estimated using histological, western blotting and PCR-RT analysis. There was a significant decrease in the collagen deposition, as indicated by Sirius red staining, in the C + GA group compared to the C group (p<0.05). This improvement was accompanied by a reduction in the number of α-SMA-positive cells observed in these animals (p<0.05). The expression of the Procollagen α1(I), TGFβ1 and TIMP1 genes was also diminished by GA administration compared to the control (p<0.001). Additionally, proteomic studies revealed reduced p65 NFκB and p38 MAPK protein levels in the C + GA group. These findings reveal the effect of GA on the regression of cirrhosis. The mechanisms of this process might involve the anti-inflammatory activity of GA, which represses the TGFβ1, p65 NFκB, and p38 MAPK-mediated signaling pathways.