黄芩素有效抑制小鼠肺炎球菌性肺炎感染引起的炎症

Baicalein Effectively Inhibits Inflammation in Mice Caused by Pneumococcal Pneumonia Infection

为了探讨黄芩素对肺炎球菌性肺炎小鼠炎症反应的影响,采用肺炎链球菌滴鼻感染小鼠肺炎模型,黄芩素低、中、高剂量组(100,200和400 mg/kg)分别灌胃给药,阳性药青霉素(PEN,0.6 mg/kg)尾静脉注射给药,1次/d,共7 d,观察药物的抗炎作用及机制。结果显示:黄芩素减少感染小鼠支气管肺泡灌洗液(BALF)中蛋白总量和细胞渗出,降低淋巴细胞和中性粒细胞比例,减少血清肿瘤坏死因子(TNF-α)、白细胞介素8(IL-8)和白细胞介素6(IL-6)含量,下调小鼠肺组织核因子-κB(NF-κB)和有丝分裂原激活蛋白激酶(p38 MAPK)mRNA的表达水平,最终提高动物存活率,减轻肺炎链球菌感染引起的肺损伤和肺水肿。黄芩素具有明显缓解炎性细胞浸润和降低炎性细胞因子水平的作用,对肺炎球菌性肺炎小鼠具有良好的保护作用,其与下调NF-κB和p38 MAPK表达水平有关。

Pneumococcal pneumonia is a major threat to global health,causing thousands of deaths every year.To investigate the effects of baicalein on inflammation in mice caused by pneumococcal pneumoniaand explore the feasibility of baicalein against pneumococcal pneumonia.Mice were nasal infected with Streptococcus pneumoniae.The low,medium and high doses of baicalein groups were administered of 100,200,and 400 mg/kg baicalein by intragastric administration respectively,and the positive drug penicillin(PEN,0.6 mg/kg)was given to the tail veininjection,1 time/d,7 days in total.The survival rates of infected mice were observed every day.The concentration of inflammatory factors from serum and the proportion of inflammatory cells in bronchoalveolar lavage fluid(BALF)was measured.The ratio of lung dry to wet weight was used to evaluate the pulmonary edema,and the lung injury was evaluated by HE staining.The expression of NF-κB and p38 MAPK mRNA level was studied by qPCR.Thre results showed Baicalein reduced the total protein and cell exudation in BALF,decreased the ratio of lymphocytes and neutrophils,reduced the serumcontents of tumor necrosis factor(TNF-α),interleukin 8(IL-8)and interleukin 6(IL-6).Although baicalein could not eliminate the number of Streptococcus pneumoniae in the lungs,HE staining and pulmonary edema assessment showed that baicalein could effectively reduce lung injury and pulmonary edema.In addition,baicalein also down-regulated the expression of nuclear factor-κB(NF-κB)and mitogen-activated protein kinase(p38 MAPK)in mouse lung tissue.Finally,the survival rates of mice treated with baicalein were significantly improved.Baicalein had potent anti-inflammatory effects on mice with pneumococcal pneumonia by decreasing inflammatory cell infiltration and inflammatory cytokine levels,which was related to the inhibited expression of NF-κB and p38 MAPK.Therefore,baicalein can be a potential candidate drug for pneumococcal pneumonia infection caused by Streptococcus pneumoniae.