无花果叶提取物对重症肺炎大鼠的保护作用及机制的初步探讨

Protective effect of fig leaf extract on severe pneumonia rats and its mechanism

目的观察无花果叶提取物对重症肺炎(SP)大鼠肺组织的影响,并初步探讨其分子机制。方法对50只SD大鼠建立SP模型,将建模成功的45只大鼠随机分为模型组、低剂量无花果叶提取物组、高剂量无花果叶提取物组,另取15只未经处理的大鼠为对照组。低、高剂量无花果叶提取物组大鼠造模后,分别给予50 mg/(kg·d)、100 mg/(kg·d)无花果叶提取物灌胃,对照组和模型组大鼠以等量蒸馏水灌胃,连续8周。酶联免疫吸附法(ELISA)检测血清中白细胞介素(IL-4、IL-6、IL-10)与肿瘤坏死因子-α(TNF-α)水平;苏木素-伊红(HE)染色检测肺组织病理变化;免疫组化染色检测肺组织中细胞间黏附分子-1(ICAM-1)和巨噬细胞炎性蛋白2(MIP-2)表达;实时荧光定量PCR(qRT-PCR)检测肺组织中ICAM-1、MIP-2 mRNA表达;蛋白质免疫印迹(Western blot)检测ICAM-1、MIP-2以及核因子κB(NF-κB)信号通路相关蛋白水平。结果与模型组比较,经过低、高剂量无花果叶提取物治疗的大鼠,血清中IL-6、IL-10、TNF-α的含量均显著下降(P<0.05),而IL-4的含量显著增加(P<0.05),大鼠肺组织损伤减轻,ICAM-1和MIP-2表达受到抑制,同时,肺组织中NF-κB p65、p-IκBα蛋白相对表达量显著下降(P<0.05)。结论无花果叶提取物可改善SP大鼠肺组织损伤,减轻炎症反应,这可能与抑制ICAM-1、MIP-2表达及NF-κB信号通路有关。

Objective To observe the effect of fig leaf extract on lung tissue of severe pneumonia(SP)rats,and discuss the molecular mechanism.Methods Fifty SD rats were selected to establish SP models,and 45 rats successfully modeled were randomly divided into model group,low-dose fig leaf extract group,and high-dose fig leaf extract group,and 15 untreated rats we included as the control group.Low-dose and high-dose fig leaf extract groups were given 50 mg/(kg·d)and 100 mg/(kg·d)of fig leaf extract for gavage.The rats in control group and model group were given the same amount of distilled water for gavage for 8 consecutive weeks.Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of interleukin(IL-4,IL-6,IL-10)and tumor necrosis factor-α(TNF-α)in serum.Hematoxylin-eosin(HE)staining was used to detect the pathological changes of lung tissue.Immunohistochemical staining was used to detect the expression of intercellular adhesion molecule-1(ICAM-1)and macrophage inflammatory protein 2(MIP-2)in lung tissue.Real-time fluorescent quantitative PCR(qRT-PCR)was used to detect the expression of ICAM-1 and MIP-2 mRNA in lung tissue.protein levels of ICAM-1,MIP-2 and NF-κB signaling pathways were determined by Western blot.Results Compared with the model group,the levels of IL-6,IL-10 and TNF-αin the serum of rats treated with low and high doses of fig leaf extract significantly decreased(P<0.05),while the content of IL-4 significantly increased(P<0.05),the lung tissue damage of rats was reduced,the expression of ICAM-1 and MIP-2 was inhibited,and at the same time,the relative expression of NF-κB p65 and p-IκBαprotein in the lung tissue decreased significantly(P<0.05).Conclusion Fig leaf extract can improve lung tissue injury and reduce inflammation in SP rats,which may be related to inhibition of ICAM-1 and MIP-2 expression and NF-κB signaling pathway.