ABSTRACT
Objective To observe the lung injury of rats caused by PM2.5 and the intervention effect of Platycodonis Radix total saponins (PGS); To discuss the repair mechanism of PGS for lung injury caused by PM2.5. Methods The model of lung injury caused by PM2.5 was induced by tracheal instillation. The rats were randomly divided into blank group, model group and PGS high-, medium- and low-dose groups, with 10 rats in each group. After medication for 14 d, BALF and left lung and right lung tissue of rats were collected. HE staining was used to observe the pathological changes of lung tissue. The contents of TNF-α, IL-6, IL-10 and IL-13 in BALF were detected by ELISA. RT-PCR was used to detect the expression of TGF-β mRNA in lung tissues. The expression of TGF-β protein in lung tissue was detected by Western blot. Results Compared with model group, TNF-α and IL-6 decreased significantly while IL-10 and IL-13 increased significantly in BALF in high- and medium-dose group of PGS. Degree of pulmonary interstitial edema and fibroplasia alleviated in PGS groups. Expressions of TGF-βmRNA and protein in lung tissue was reduced in PGS groups. Conclusion PGS can alleviate inflammatory injury caused by PM2.5 via regulating the balance of cytokine and down-regulating the expression of TGF-β and inhibiting the development of fibrosis, which results in the protection and repair on the lung injury of rats caused by PM2.5.