Dexamethasone Combined With Puerarin In Treatment Of Acute Paraquat-Poisoned Rats

Objective: To explore an effective and feasible treatment for acute paraquat poisoning, a study was designed to compare therapeutic effect of dexamethasone, puerarin and dexamethasone combined with puerarin for paraquat- poisoned rats.Method: Thirty clean Sprague Dawley rats were randomly assigned to five groups:control group(same volume saline i.p),model group(PQ 25mg/kg i.p), dexamethasone group(DEX 20mg/kg i.p after PQ 25mg/kg given two hours), puerarin group(PU 100mg/kg i.p after PQ 25mg/kg given two hours) and combined group(DEX 20mg/kg i.p and PU 100mg/kg i.p after PQ 25mg/kg given two hours). Above-mentioned treatments were repeated 26 hours later. 26 th ~50th h urine was collected for analysis of urinary N-acetyl-beta-D-amino glycosidase enzymes(NAG). At 50 th h, abdominal aortic blood was collected for PO2 test after anesthesia. Lung and kidney tissues were harvested for lung index, kidney index, histopathology(blinded), and analyses of malonaldehyde(MDA), superoxide dismutase(SOD) and myeloperoxidase(MPO). At the second stage, another 30 SD rats were treated as above but not sacrificed to observe the condition of rats and note survival situation. Statistical analyses were performed using SPSS19.0. All variable data was presented as group means±SEM. Statistical significance of differences between groups was determined using one-way ANOVA followed by SNK test for multiple comparisons when equal variances assumed, while using Games-Howell test when equal variances not assumed. Survival data were analyzed by survival analysis. Significance was declared for P values<0.05.Results: Lung index,kidney index(not in the PU group), NAG, MDA and MPO level in lung and kidney tissue homogenate of each group were higher than that of the control group; while PO2 and SOD were extremely lower(P<0.05). We found that only in the puerarin group, the lung index, NAG and MDA, MPO level in lung and kidney tissue homogenate were lower than that of the model group, while PO2, SOD were higher(P<0.05). Improvement was not obvious in the dexamethasone group and the combined group not only the indicator of kidney injury but also pathologic change. The cum survival in thirty days of the control group 、 model group 、dexamethasone group、puerarin group、combined group was 100%, 0, 16.7%, 50%, 33.3%, respectively.Conclusion: Dexamethasone can improve the prognosis of acute paraquat poisoning rats, it can provide lung protection, but can not provide significant protective effect on kidney; Puerarin has therapeutic effect on acute PQ poisoning, it can provide not only lung protection but also kidney protection; The effect of treatment with dexamethasone combined puerarin is not better than with single one, probably because the stability of puerarin solution is poor, the drug reaction between the two drugs weakened its therapeutic effect when injected by intraperitoneal.