This study was performed to evaluate the influence of simultaneous administration of aqueous
green tea extract (1.5 %) with methotrexate (0.5 mg /kg) on the status of glutathione (GSH) in liver
tissue, with measuring the activity of serum liver enzymes [alanine aminotransferase (ALT), aspartate
aminotransferase (AST)] and serum bilirubin levels. Administrations of aqueous green tea extract alone
resulted in a significant increase in liver tissue GSH level and when it was used with MTX it
ameliorated MTX-induced changes in level of this parameter. Regarding enzymes activities,
administration of aqueous green tea extract resulted in an alleviating effect on MTX-induced elevation
in serum ALT activity with a non-significant reduction in serum AST activity; it also significantly
reduced MTX-induced elevation in total serum bilirubin level, these effects may be related to direct or
indirect antioxidant property of green tea extract .