Effect of Supplementing Qi and Activating Blood Circulation Herbs on Inflammatory Factors and Toll-like Receptor 4 mRNA Expression in Rats with Acute Lung Injury
Objective:To observe and investigate the effects of supplementing Qi and activating blood circulation herbs on inflammatory factors in bronchoalveolar lavage fluid (BALF) and Toll-like receptor 4 mRNA expression in lung tissues of rats with acute lung injury (ALI) induced by lipopolysaccharide (LPS).Method:Seventy-two healthy male SD rats were randomly divided into normal group,model group,dexamethasone group and supplementing Qi and activating blood circulationherbs group,n =18 in each group.ALI models were established by intratracheal instillation of LPS (5 mg·kg-1),while normal group received normal saline.Three days before and after making the models,the corresponding drugs or normal saline were given in each group by gavage.Six rats in each group were put to death at the end of the 8,24,72 h after modeling.Then the pathological changes of lung tissues were observed under light microscope;the concentrations of tumor necrosis factor-α (TNF-α),interleukin 1β (IL-1β),and interleukin 6 (IL-6) in rat bronchoalveolar lavage fluid (BALF) were measured by enzymelinked immune sorbent assay (ELISA),and the TLR-4 mRNA expression levelsin lung tissues were determined by real-time polymerase chain reaction (Real-time PCR).Result:For the pathological score of lung tissues,as compared with normal group,LPS in other groups exhibited a higher level (P < 0.01);as compared with model group,dexamethasone group and Chinese herbs group exhibited a lower level (P < 0.05,P < 0.01) and the level was lowest in 72 h.For the contents of TNF-α,IL-1β and IL-10 in BALF,LPS in other groups displayed an obvious increase as compared with normal group,but the levels in dexamethasone group and herbs group were decreased as compared with model group (P < 0.01);the level in model group was increased gradually over time in model group and the levels indrug intervention groups were decreased over time (P < 0.05,P < 0.01).For the TLR4 mRNA expression level in lung tissues,as compared with normal group,LPS in other groups exhibited a higher level (P <0.01) and the level was highest in model group at 8 h;as compared with the model group,the expression levels in herbs group were decreased at various time points (P < 0.05,P < 0.01).Conclusion:Supplementing Qi and activating blood circulation herbs could decrease the levels of TNF-α,IL-1β and IL-10 in BALF in rats with ALI induced by LPS,improve the pathological changes in lung tissues,and the prevention and treatment mechanism for ALI may be associated withinhibiting the TLR4 mRNA expression.