Abstract
This study was designed to assess the effect of green tea, an aqueous extract of
Camellia sinensis, on the oxidative stress, antioxidant defense system and liver pathology of
Schistosoma mansoni-infected mice. Green tea at concentration of 3% (w/v) was given orally to treated mice as sole source of drinking water from the end of the 4th week to the end of 10th week post-infection; untreated mice were allowed to drink normal water. The data of the studied
S. mansoni-infected mice exhibited a suppression of hepatic total antioxidant capacity, superoxide dismutase (SOD), catalase (CAT) activity and glutathione content. The liver lipid peroxidation was deleteriously elevated in
S. mansoni-infected mice. The hepatic total protein content, AST and ALT activities were profoundly decreased in the
S. mansoni-infected mice. Most hepatocytes were damaged and showed abnormal microscopic appearance with aggressive necrosis. Both total protein and glycogen levels have been greatly reduced as indicated by histochemical examination. The treatment of
S. mansoni-infected mice with green tea succeeded to suppress oxidative stress by decreasing the lipid peroxides but failed to significantly enhance the antioxidant defense system and deteriorated changes owing to liver damage and necrosis. In consistence with biochemical data, histopathological and histochemical data indicated that treatment of
S. mansoni-infected mice with green tea could ameliorate hepatocytes thus reduce cellular necrosis and partially restore both total protein and glycogen levels. Thus, the study concluded that the green tea suppresses the oxidative stress through its constituent with free radicals scavenging properties rather than through the endogenous antioxidant defense system.