Black tea prevents high fat diet-induced non-alcoholic steatohepatitis

The chemoprotective actions of aqueous black tea extract (BTE) against high-fat diet (HFD) (60%)-induced non-alcoholic steatohepatitis (NASH) were examined in Wistar rats of both sexes. The results indicated that the HFD rats had higher concentrations of serum glucose, cholesterol, triglycerides, low-density lipoprotein, very low-density lipoprotein, high-density lipoprotein and bilirubin than the corresponding control rats. The enzymes serum aspartate aminotransferase and alanine aminotransferase, which are indicators of liver function, also exhibited higher levels of activity in HFD rats. BTE extract supplementation was found to correct such steatohepatitis-linked biochemical changes. HFD-induced steatohepatitis was associated with substantial pro-oxidant conditions in rat liver, as evidenced by the higher content of malondialdehyde, nitric oxide production and glutathione depletion, with a concomitant decrease in liver antioxidant status caused by reducing superoxide dismutase and catalase activity. In addition, rats with steatohepatitis showed a significantly higher expression of inducible nitric oxide synthase, caspase-3 activity and DNA fragmentation. BTE reversed the changes in the pro-oxidant and antioxidant status of the liver, and protected against apoptotic, cytogenetic and hepatocellular damage. In summary, these data suggest that nutritional support with antioxidants may be useful in preventing oxidative damage and the progression of NASH.