An experimental study on dexamethasone combined with puerarin in treatment of acute paraquat-poisoned rats / 中国中西医结合急救杂志

ABSTRACT

ObjectiveTo explore the therapeutic effect and mechanism of dexamethasone combined with puerarin for treatment of paraquat (PQ) poisoned rats.Methods Thirty Sprague Dawley (SD) rats were divided by random number table into 5 groups control, model, dexamethasone, puerarin and combined groups, 6 rats in each group. The PQ poisoned rat model was established by intraperitoneal injection of PQ 25 mg/kg (1 mL), while in the rat of the control group, the same volume of normal saline was injected intraperitoneally. After 2 hours, in the rat of dexamethasone group, 20 mg/kg dexamethasone in 1.5 mL was injected intraperitoneally, and in the rat of puerarin group, 100 mg/kg puerarin in 1.5 mL was injected intraperitoneally. In the rat of combined group, 20 mg/kg dexamethasone combined with 100 mg/kg puerarin in a total amount of 1.5 mL was injected intraperitoneally. In the control group and model group, 1.5 mL of normal saline was injected intraperitoneally. The above mentioned treatments were repeated once more 26 hours later. In 26-50 hours after modeling, urine was collected, and urine N-acetyl-beta-D-amino glycosidase enzymes (NAG) was tested; at the 50th, abdominal aortic blood was collected to test oxygen partial pressure (PaO2). The lung index, kidney index, and the levels of malonaldehyde (MDA), superoxide dismutase (SOD) and myeloperoxidase (MPO) were measured in the left lung and kidney tissue homogenates separately; the right lung and kidney were harvested to observe pathological changes under light microscope. Another 30 SD rats were treated the same as above measures but no sacrifice to observe 30-day survival rate in each group.Results The lung index, kidney index, NAG in urine, MDA and MPO levels in lung and kidney tissue homogenates in model group were significantly higher than those in the control group [lung index 9.80±1.83 vs. 4.97±1.14, kidney index 9.40±1.32 vs. 7.01±0.32, NAG (U·kg-1·day-1) 1.93±0.18 vs. 0.41±0.03, MDA of lung (nmol/mg) 1.04±0.15 vs. 0.28±0.10, MDA of kidney (nmol/mg) 1.39±0.16 vs. 0.66±0.13, MPO of lung (U/g) 1.14±0.08 vs. 0.81±0.06, MPO of kidney (U/g) 0.88±0.08 vs. 0.52±0.12]; while PaO2 [mmHg (1 mmHg = 0.133 kPa) 59.83±4.40 vs. 97.00±2.83] and SOD (U/mg) lung was 27.38±3.48 vs. 86.88±5.88; kidney was 24.18±3.74 vs. 57.86±6.14) were obviously lower than those in control group (allP 0.05).Conclusions Dexamethasone can improve the prognosis of rats with acute paraquat intoxication, it can provide lung protection markedly, but cannot provide significant protective effect on kidney; puerarin has therapeutic effect on rats with acute PQ poisoning, it can provide not only lung protection but also kidney protection. The effect of treatment with dexamethasone combined with puerarin is not superior to that by using dexamethasone or puerarin alone.