Effects of Niupo Zhibao pellet on helper T cell expression in rats with endotoxin-induced acute pulmonary fibrosis / 中国中西医结合急救杂志

ABSTRACT

Objective To observe the effects of Niupo Zhibao pellet, a compound traditional Chinese herbal medicine,on helper T cell(Th cell)expression in rats with endotoxin-induced rapid pulmonary fibrosis (RPF). Methods Two hundred and twenty-four Wistar rats were randomly divided into four groupsnormal control,model,dexamethasone(DXM)and Niupo Zhibao pellet(NW)groups(each n=56). By using endotoxin three-hit regimen,the RPF model was established. Three days before and 7 days after the establishment of models in NW group,they were administered with the pellet by intragastric feeding,50 mg/100 g of distilled water twice a day,a total of 10 days medication. Rats in DXM group received DXM intraperitoneal injection,3.0 mg/kg once a day for consecutive 7 days. Rats in normal control group were administered with the same volume of distilled water by intragastric administration. On 1,3,7,9,14,21,28 days after the administration,blood and bronchoalveolar lavage fluid(BALF)specimens were collected. The contents of γ-interferon(IFN-γ)and interleukin-4(IL-4) in the serum and BALF were investigated by enzyme-linked immunosorbent assays(ELISA). The lung tissue was stained by hematoxylin-eosin(HE)and Van Gieson respectively. Morphological changes in lung tissue were observed under light microscope. Results HE staining showed that the pulmonary interstitial tissues of rats in model group were thickened,there was a large amount of inflammatory exudates,and micro thrombi were seem in alveolar space. The pulmonary interstitial tissues in rats of DXM group were thickened too,but the inflammatory exudate in alveolar space was much less. Compared to rats in DXM group,the rats in NW group had slightly more inflammatory exudate and their pulmonary interstitial tissues were basically normal. Van Gieson staining showed that the expression of collagen fiber in model group was obvious,that of DXM group less than the former one but not significant,while that in the NW group was reduced markedly. ELISA assays demonstrated that the levels of IFN-γin BALF and serum in model group were increased significantly,those in DXM group were lowered to the minimum on the 7th day,raised to the levels before treatment on the 14th day,and gradually declined on the 21st day. In the NW group,the IFN-γwas consistently at a high level,and then gradually declined at a slow rate. After 7 days of drug administration,the IFN-γ levels in BALF and serum at various time points in NW group were obviously higher than those in model and DXM groups〔BALF(ng/L)140.47±4.22 vs. 149.23±8.35,90.67±6.65;serum(ng/L)140.47±4.15 vs. 100.43±11.05,99.35±7.85,P<0.05 or P<0.01〕. The levels of IL-4 in BALF and serum in each group increased significantly,reached to their maximum on the 7th day,and then gradually decreased. After the drug administration for 28 days,those levels in NW group were obviously lower than those in model and DXM group〔BALF(ng/L)6.60±1.05 vs. 7.20±1.25,8.55±1.05,serum(ng/L)6.75±1.05 vs. 7.21±1.25,8.25±1.15,P<0.05 or P<0.01〕. Conclusion Niupo Zhibao pellet can suppress inflammation,ameliorate injury of lungs and inhibit lung fibrosis by promoting IFN-γsecretion,restraining IL-4 secretion and adjusting the imbalance of Th cells.