Abstract: ［Abstract］〓Objective〖HTSS〗〓To explore the mechanism of Xuebijing in the treatment of acute paraquat poisoning by studying the effects of Xuebijing on the activity of superoxide dismutase(SOD) and glutathione peroxidase(GSHPX), the content of malonaldehyde(MDA) and the expression of tumor necrosis factorα(TNFα)， interleukin10(IL10) in acute paraquat lung tissue.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓On the base of random number table,108 Wister rats were divided into control group(36 rats), poisoned group(36 rats), treatment group(36 rats). On 1 st, 3 rd, 7 th, 14 th, 21 st and 28 th day，six rats from each group were anaesthetized by intraperitoneal injection of chloral hydrate. Open chest under ether anesthesia and leave the right lower lung tissue specimens to measure the activity of SOD and GSHPX and the content of MDA. The expression levels of TNFα,  IL10 in lung tissue were detected by immunohistochemical staining.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓The activity of SOD in the poisoned and treatment group increased gradually along the length of time(P＜005). The activity of SOD in each time point of the poisoned group was lower than that of the control group(P＜005). The activity of SOD in the treatment group was higher than that of the infected group, but it was still lower than that of the control group(P＜005). The activity of GSHPX increased gradually along with the time in the poisoned and the treatment group(P＜005).The GSHPX activity in the poisoned and the treatment group was lower than that in the control group at all time points, and the GSHPX activity at each time point in the treatment group was higher than that in the poisoned group(P＜005). The MDA activity in the poisoned and the treatment group gradually was decreased along with the time length(P＜005). The MDA activity in the posioned and the treatment group at each time point was higher than that in the control group, and the MDA activity at each time point in the treatment group was lower than that in the posioned group(P＜005). The expression of TNFα protein and the content of IL10 in the lung tissue of the poisoned and the treatment group increased first and then decreased. The expression level of TNFα, IL10 protein in lung tissue of the poisoned and the treatment group was higher than that of the control group(P＜005). The expression level of TNFα, IL10 in lung tissue at each time point in the treatment group were lower than those in the exposure group(P＜005).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓Oxygen free radicals and cytokine TNFα, IL10 play an important role in lung injury induced by paraquat in rats. Xuebijing can reduce the injury of lung tissue in paraquatpoisoning rats.

Key words: poisoning； paraquat； Xuebijing, rats