Acute Injury Effects Of Paraquat On Pulmonary Vascular Endothelial Cells And Protective Effects Of Xuebijing Injection

ObjectiveParaquat(PQ), a world-widely used as a contact defoliant and herbicide, appropriately applies to eliminate weeds in rural areas. However, there are numerous fatalities each year, mainly caused by accidental or voluntary ingestion etc. The main molecular mechanism of its toxicity is based on increase of oxygen free radical PQ-induced, derease of super oxide dismutase(SOD) activity and content of sulfhydryl compound etc, and thus result in lipid peroxidation and inflammatory reaction and so on. This further results in organ dysfunction like lung, liver, kidney etc. PQ accumulates in the lung especially, and thus causes lung more serious injury than others. PQ poisoning is an extremely frustrating condition to manage clinically, due to the elevated morbidity and mortality observed so far and due to the lack of effective treatments to be used in humans. Xuebijing injection, a traditional Chinese drug preparation, are extracted from red peony root, chuanxiong, danshen root, safflower and angelica, have effects of antagonism to endotoxin,eliminating oxygen free radical, protecting vascular endothelial cell, anti-inflammatory etc. Aim of this topic is to investigate acute injury effects of PQ on pulmonary vascular endothelial cells(PVEC) and protective effects of Xuebijing injection on them by both animal experiment and cell culture. Further to offer theoretical and experimental supports to clinical application of Xuebijing injection to PQ poisoning.MethodsMethod one: 100 SD rats were randomly divided into five groups with 20 rats each group: control group, PQ group, and low, middle, high concentration Xuebijing groups. Rats in PQ group, low, middle and high concentration Xuebijing groups received 18mg/kg of PQ by intraperitoneal injection, and rats in control group received equal of normal saline. After 2 hours low, middle and high concentration Xuebijing groups were treated with 1.25, 2.5, 3.75mg/kg of Xuebijing injection respectively by intraperitoneal injection ,once a day. Animals were sacrificed at an interval of 1, 2, 3 and 4days respectively (n=5) after administration of the above agents. The total activity of SOD, the content of malondialdehyde (MDA) and inducible nitric oxide synthase (iNOS) in lung homogenate were measured by spectrophotometry. Pathological changes were observed.Method two: the primary passage cells of PMVECs cultured were divided into five groups: control group, PQ group and low, middle, high concentrations Xuebijing groups. PQ group, low, middle and high concentrations Xuebijing groups were treated with 0.1mmol/L of PQ, and Control group with equal of culture fluid. After 30 mintes Xuebijing whose concentrations in culturemedium were 10, 20, 50mg/mL respectively were added into low, middle and high concentrations Xuebijing groups. The total activity of SOD, the content of MDA in supernatant were measured by spectrophotometry at an interval of 3, 12, 24, 48 hours, and vWF, ET by ELISA.ResultsResult one: There are significant differences in the total activity of SOD and the contents of MDA, iNOS compared with blank control group(P<0.01). Xuebijing injection can concentration-dependently inhibit decreasing of the total activity of SOD, increasing of the content of MDA, iNOS accordingly. High concentrations Xuebijing group are the most significant compared with PQ group Except for iNOS in the first day(P<0.01 or 0.05). Meanwhile, the total activity of SOD, the contents of MDA, iNOS time-dependently present different changes in Xuebijing groups of different concentrations. In the first two days, increases of the total activity of SOD, decreases of the contents of MDA, iNOS are dramatic, and following two days their changes are slow. Pathological changes also are significant in PQ group.Result two: There are significant differences in the total activity of SOD and the contents of MDA, vWF and ET compared with blank control group(P<0.01). Xuebijing can concentration-dependently inhibit decreasing of the total activity of SOD, increasing of the content of MDA, vWF and ET accordingly. And high concentrations were most significan(tP<0.01or 0.05). Meanwhile, the total activity of SOD time-dependently presents reduction to a certain extent in Xuebijing groups of different concentrations, while the contents of MDA, vWF and ET present increasing trend. But the speeds of their changes are relatively slow compared with PQ group.ConclusionsReactive oxygen generated by PQ poisoning can directly or indirectly injury PVEC, inhibit the total activity of SOD, increase contents of MDA, iNOS, vWF, ET, and result in acute lung injury(ALI). Xuebijing injection can protect PVEC from PQ-induced injury, raisie the total activity of SOD, reduce the contents of MDA, iNOS, vWF and ET, and thus alleviate ALI.