Study On The Protection Mechanism Of Xuebijing Injection To Lung Injury Of Paraquat Poisoning In Rats

IntroductionParaquat is bipyridine herbicides. Because LD50 of paraquat is small and Paraquat is toxic to all organs of the body, so the smaller dose poisoning can cause delayed lung fibrosis. High-dose poisoning can cause multiple organ failure and rapid death. It's mortality rate remains at high level. Currently There is no effective antidote for PQ poisoning. The effect of conventional treatment is poor. Xue bi-jing injection is intravenous formulations, which developed under the guidance of the theory of"bacteria, poison, inflammation". In recent years, some people used Xue bi-jing injection for the treatment of PQP, and it showed some preliminary effects, but its mechanism is still in the exploration.ObjectiveTo investigate the role of the inflammatory response in the pathogenesis of acute lung injury caused by PQP, and to investigate the impact of Xue bi-jing injection on proinflammatory mediators and anti-inflammatory mediators of PQP rats and lung injury protection mechanisms.MethodsWistar rats were randomly divided into three groups, normal control group (control group)was given 1 ml normal saline one-time gavage; exposure + saline treatment group (exposed group), 20% PQ was diluted by normal saline to 1 ml at 50mg / kg one time gavage, then exposed group was given intraperitoneally saline 4 ml / kg one time everyday, and continuous administration 7days or untill to be executed For exposure + Xue bi-jing treatment group (treated group ), the treated group was treated by the same process of poisoning , then Xue bi-jing injection was given intraperitoneally at 4 ml / kg one time everyday, and continuous administration to 7days or untill to be executed. Serum and lung tissue specimen of the three groups was collected to detect the level of TNF-αand IL-10, and to ohserve the ratio continuous changes of TNF-α/ IL-10. At the same time, the pathological changes of the lung tissue were observed under light microscope.ResultsThe levels of serum TNF-α, IL-10 of the latter two groups had significantly increased comparing to the control group. ater being poisoned, the serum levels of TNF-α, IL-10 in exposed group increased significantly, whiched reach to peak at 3 d and still not back to normal levels at 14 d. The ratio of TNF-α/ IL-10 significantly increased in 7 d; at each time point, serum levels of TNF-α, IL-10 of the treatment group were higher than the control group, but its elevated level is lower than the exposed group. TNF-α/ IL-10 ratio reached to the lowest level in the first 3 d after poisoning, and the differences were statistically significant. The signs of lung tissue damage were observed in both groups. The control group detected the signs of pulmonary fibrosis at 14 d; the inflammatory response of treated group was lighter than the control group, and the treated group had no signs of pulmonary fibrosis.DiscussionThe characteristic changes of PQ poisoning is lung injury, which is also the main reason of death of PQ poisoning patients. At present, the mechanism of lung injury caused by PQ mainly involves a large number of oxygen free radicals, which causes inbalance of lipid peroxidation and the damage of alveolar typeⅠandⅡepithelial cell; imbalance of intracellular calcium homeostasis damages the membrane destruction of the cytoskeleton, which causes the cell membrane permeability. Increased and pulmonary interstitial changes. the changes of enzyme cause alveolar epithelial apoptosis. Over expression and secretion of endothelin cause contraction of tracheobronchial muscle and vascular smooth muscle in pulmonary, which leads to microcirculation, ischemia, hypoxia, and accelerate the lipid peroxidation damage of lung, and so on.In recent years, the research on cytokines in the pathogenesis of lung injury has aroused people's attetion. People made concept of lung cell and cytokines network. It is considered that the delicate balance between inflammatory response and anti-inflammatory response plays an important role in the process of the complex pathophysiological mechanism of the lung injury. The body is in a non-physiological stress when PQP, meantime for PQP often followed with hypoxic, tissue damage which can induce SIRS, so the inflammatory response involved in the pathogenesis of lung injury triggered by PQP.TNF-α, as a primary cytokines, plays an important part in a series of pathological changes cansed by synthesis and release of inflammatory mediators, neutrophil accumulation in the lungs, complement activation and oxygen free radical formation, and TNF-αcan induce pathological injury in its Ligher concentration Our study confirmed: serum levels of TNF-αincreased in both treatedt group and control group, reaching to the peak in 3 d, remaining at a relatively high level in 7 d, and the serum levels of TNF-αwas higher than the control group in 14 d, which suggested that TNF-αinvolved in the pathogenesis of PQP and played an important role in the later process of lung injury caused by PQP.IL-10 is anti-inflammatory cytokines in the inflammatory response, which has dual attributes of anti-inflammatory and suppressing the body's immune. On the early stage anti-inflammatory media (IL-10) can inhibit the release of inflammatory mediators appropriately and the acute lung injury caused by inflammation. However, the over-strong anti-inflammatory response may lead to immunosuppress and enhanced susceptibility to sepsis, which may trigger further induce or aggravate ALI / ARDS. This study suggested: levels of serum IL-10 of exposure group and the treatment group were higher than those in the control group, which reached a peak in 3 d, and remained relatively high level in 7 d, and serum IL-10 levels of exposure group were still higher that that of control group in 14 d which suggested that in the course of PQP anti-inflammatory response existed, and IL-10 also involved in the pathogenesis of PQP.This study observed the continuous change of the TNF-α/ IL-10 ratio. The results showed that there was no significant difference between serum TNF-α/ IL-10 ratio levels in the exposed group and the control group, but tle serum ratio significantly increased in 7d after poisoning, then decreased, and had not reduced to normal level untill 14d; serum of TNF-α/ IL-10 of the treatment group rats decreased when compared with the control group in 1d after poisoning, but the difference was not obvious, and the ratio reached to the lowest level in 3d after poisoning and then gradually rised. Experiment shows that: the pro-inflammatory response / anti-inflammatory response imbalance exists in the PQP course and TNF-α/ IL-10 ratio reflects the direction of the body inflammatory response, which can be the important reference reflecting balance of SIRS / CARS.Injection of Xue bi-jing has the major components of safflower, Chuanxiong, TPG, Salvia, such as Angelica. Study found that blood would have the function of reducing pro-inflammatory cytokines, blocking excessive inflammatory response; promoting immune function and improving the immune imbalance; inhibiting lipid peroxidation; protecting endothelial cells, which play a protection role of lung injury caused by PQP.This paper has focused on the influence of Xue bi-jing injection on the level of serum TNF-αand IL-10, demonstrates that the Xue bi-jing injection will lower both serum levels of TNF-αand IL-10 and maintain TNF-α/ IL-10 ratio closed to a normal level, thereby regulate SIRS / CARS balance, and slow the progress of organ damage.ConclusionWhen PQP, levels of pro-inflammatory serum medium (TNF-α) and anti-inflammatory media (IL-10) were significantly higher indicating that the inflammatory response involved in the pathological process of the PQP, which was one of the important mechanisms of lung injury PQP caused; serum levels of TNF-α/ IL-10 ratio reflecting the immune status which can be used as the important reference of SIRS / CARS balance; inflammatory mediators (TNF-α) and anti-inflammatory media (IL-10) levels will be reduced by Xue bi-jing injection of serum, thus conducive to the prevention of the body's excessive inflammatory response; Xue bi-jing injection can lower levels of TNF-αand IL-10, maintain the balance of pro-inflammatory / anti-inflammatory, thus play the protection role of rats lung injury caused by PQP.