Effect of tea polyphenol on cytokine gene expression in rats with alcoholic liver disease

Oxidative stress plays a pathogenetic role in initiation and progression of hepatic damage caused by alcohol. Recently, antioxidants have received considerable attention. Green tea polyphenols have both antioxidant and antiinflammatory properties. This study was designed to evaluate the effect of tea polyphenol (TP) on alcohol-induced liver injury in rats.

The rats were divided randomly into 3 groups: group A gastrically infused with alcohol for 12 weeks, group B fed with alcohol plus TP (250 mg/kg.d) simultaneously, and group C (control group) gastrically infused with normal saline. At the end of 12 weeks, the rats were sacrificed. The liver specimen of each rat was taken for histological examination. All data were statistically analyzed in quantum and semi-quantum. Gene expression of cytokines of each group was determined.

At the end of 12 weeks, hepatic injury of different degrees developed in group A and group B compared to group C. The degree of hepatic injury was attenuated in group B, with slight steatosis, liver cellular swelling in small areas; less spot and focal necrosis, no bridging necrosis, less mega-bubble steatosis and less collagen deposition in contrast to group A. Gene expressions of IL-3, IL-4, IL-1R2, IL-6R, IL-7R2 were up-regulated in group B compared with group A, but those of IL-3Ra, IL-1R1 were down-regulated. Gene expressions of IL-13, IL-1R1, IL-7R2, EPO-R, LIFR were up-regulated in group A compared with group C, but those of IL-1R2, IL-5R2, CSF1, CD27, IL-6R were down-regulated.

TP is able to attenuate alcoholic liver damage. Cytokine may contribute to alcoholic liver disease.