Therapeutic effect of tetrandrine combined with dexamethasone on acute paraquat poisoning in rats

Objective To explore the antagonistic effects of combined use of tetrandrine(TET) and dexamethasone(DEX) on lung injury induced by acute paraquat poisoning in rats.Methods 104 Wistar rats were randomly divided into experimental group(96 rats) and control group(8 rats),the experimental group was subdivided into 4 groups,non-treatment group,TET treatment group,DEX treatment group and combined treatment group,24 rats in each group.Rats in experimental groups were intraperitoneally given 20 mg/kg paraquat per day for 1,3 or 7 days,respectively;the control rats were only injected intraperitoneally with same volume of saline solution.Six hours later,the rats in TET treatment group were orally given 30 mg/kg of TET per day,also for 1,2 or 7 days,respectively;while the rats in DEX group were given 3 mg/kg DEX intraperitoneally at 1,12,24,48 and 72 h after exposure of paraquat,the rats in TET plus DEX group were received both therapies mentioned above.Then,eight rats from each group were sacrificed at 1,3 or 7 days after experiment,and the levels of malondialdehyde(MDA),activities of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) in plasma of rats were determined,the histological changes in lungs were also observed at the same time.Results(1) The plasma levels of MDA at 1d and 3d after experiment were significantly higher,and the plasma activities of GSH-Px and SOD at 1d after experiment were significantly lower in rats of non-treatment group than those of control group(P 0.05);however,compared with those of DEX treatment group,the plasma activity of GSH-Px was significantly lowered(P 0.05),but plasma level of MDA and activity of SOD in both DEX and TET treatment group and the plasma activity of GSH-Px in the TET treatment group were failed to show any significant difference;while the MDA level,and SOD and GSH-Px activities at 1d after experiment showed significant differences between combined treatment group and non-treatment group(P 0.05).(2)Compared with rats in non-treatment group,the alleviated toxic manifestations as well as higher survival rates were found in DEX treatment group and combined treatment group.(3) The integralscores of pulmonary fibrosis in treatment groups were significantly lower than those in non-treatment group.Conclusions Combined use of TET and DEX showed stronger antagonistic effects on lung injury caused by acute paraquat poisoning.