RESUMO
OBJECTIVE: To study the effect of N-acetylcysteine (NAC) on the egg granuloma in hepatic tissue of mice infected with Schistosoma japonicum. METHODS: 36 mice were randomly divided into normal group, infected group and NAC group, each with 12 mice. The mice in the latter two groups were each infected with 25+/-2 cercariae of S. japonicum through the skin of abdomen. NAC solution was orally given to the mice of NAC group, 200 mg/kg, 2 times/d from the day of infection through to the 42nd day. Mice in the other 2 groups were given 2 ml normal saline daily. The mice were all sacrificed at the end of the 42nd day and their livers were collected for pathologic observation. Area of the egg granuloma was measured with computer image analysis software. Concentration of nitric oxide (NO) and reduced glutathione hormone (GSH), and the activity of glutathione peroxidase (GSH-PX) in serum and hepatic tissue, and the activity of inducible nitric oxide synthase (iNOS) in the hepatic tissue were all detected. RESULTS: Number of the single egg granuloma of "+,++,+++" grade were 1.80+/-0.25, 1.37+/-0.23 and 0.53+/-0.15 respectively in NAC treated group, which were less than those of infected group (3.70+/-0.28, 2.77+/-0.25 and 2.00+/-0.14 respectively) (P<0.05). The serum NO and GSH concentration was 0.53+/-0.17 and 229.66+/-9.47 respectively in NAC group, lower than those of infected group (2.64+/-0.31 and 312.47+/-18.55 respectively) (P<0.05), but its GSH-PX activity was 1101.99+/-140.81, higher than that of infected group (663.66+/-25.59) (P<0.05). The concentration of NO and GSH, and the activity of iNOS and GSH-PX in hepatic tissue of NAC group were 6.85+/-0.30, 13.44+/-0.40, 358.40+/-19.15 and 110.84+/-10.93 respectively, lower than those in infected group (8.26+/-1.69, 28.40+/-0.56, 1132.44+/-52.82 and 226.26+/-16.25 respectively) (P<0.05). CONCLUSION: NAC may have the effect of retarding pathological change of the liver, which may associate with the decrease of NO and GSH in serum and hepatic tissue and iNOS activity in the tissue.
