Effects of Astragalus on the balance of Th1/Th2 cytokines and free radical metabolism in rat model of pulmonary fibrosis

Objective To observe the effects of Astragalus decoction and Astragalus saponin on the balance of T helper1/T helper2 (Th1/Th2) cytokines,nitric oxide (NO),superoxide dismutase (SOD),malondialdehyde (MDA),and the pathomorphological features in bleomycin (BLM)-induced pulmonary fibrosis rats,and to explore the underlying mechanism. Methods Total of 60 Wister rats were evenly randomized into control,BLM model,Dexamethasone,Astragalus decoction,and Astragalus saponin groups. Pulmonary fibrosis model was established by injection of BLM via trachea (5 mg/kg). After 24 h,rats in the five groups were given corresponding drugs by intragastric administration once daily. At the 14 d and 28 d,6 rats from each group were sacrificed for detecting the levels of Interleukin-4 (IL-4),interferon gamma (IFN-γ),and NO in the serum,as well as the changes of SOD,MDA,and pathomorphological feature in the lung tissue. Results In comparison with blank control group,the levels of IFN-γ and SOD,as well as the ratio of IFN-γ/IL-4 were significantly lower,while IL-4,NO,MDA considerably and the degree of fibrosis were higher in BLM model group (P0.05); whereas compared with model group,the IFN-γ level,the SOD level,and the ratio of IFN-γ/IL-4 were significantly higher (P0.05),the levels IL-4,NO,and MDA were significantly lower,as well as the fibrosis degree was more mitigative in Astragalus decoction and Astragalus saponin groups (P0.05). No significant differences of these indexes were found between Astragalus decoction group,Astragalus saponin group,and Dexamethasone group (P0.05). Conclusion Astragalus decoction and Astragalus saponin have the inhibitory effects on the process of pulmonary fibrosis,whose mechanisms maybe relate to balancing cytokine,regulating the metabolism of nitric oxide oxidative free radical.