Protective effect and mechanism of Jinshuibao Tablets on lung injury induced by PM2.5 in rats / 中草药

ABSTRACT

Objective: To observe the protective effect of Jinshuibao Tablets on lung injury of rats induced by particulate matter (PM2.5), and investigate its mechanism. Methods: A total of 60 healthy adult male SD rats were randomly divided into five groups, the control group, the model group and Jinshuibao Tablets (low, moderate and high-dose) groups that were administered with drug through gavage at the doses of 0.225, 0.450, and 0.900 g/kg body weight (BW), with twelve rats in each group. The blank group was treated with normal saline by intratracheal instillation, the other groups were exposed by intratracheal instillation of PM2.5 saline suspension with the dose of 10 mg/kg BW, repeated three times per week for four weeks. At the end of the exposure, the rats in each group except control and model groups were given Jinshuibao Tablets suspension with the doses of 0.225, 0.450, and 0.900 g/kg BW, repeated once a day for 14 d. The peak expiratory flow (PEF), forced vital capacity (FVC) and volume expired in first 30 ms of fast expiration (FEV0.3) were measured, and the ratio of FEV0.3/FVC was calculated. The collected bronchoalveolar lavage fluid (BALF) was analyzed for the levels of interleukin-6 (IL-6), necrosis factor alpha (TNF-α), and eosinophils (EOS). The level of transforming growth factor-β1 (TGF-β1) was analyzed in lung homogenate. The histological changes of lung were observed. The protein kinase B (Akt), phosphorylation-protein kinase B (p-Akt), α smooth muscle actin (α-SMA) and matrix metallopeptidase 9 (MMP-9) of lung were assayed by western blotting. Results: Compared to the model group, the PEF, FVC, FEV0.3 and FEV0.3/FVC of the moderate and high-dose groups were significantly increased (P < 0.01), the levels of IL-6, TNF-α, EOS, TGF-β1 in moderate and high-dose groups were significantly decreased (P < 0.05, P < 0.01). The pathological changes of the lungs in moderate and high-dose groups treated with Jinshuibao Tablets were obviously relieved. The expression of p-Akt, α-SMA, and MMP-9 in the moderate and high-dose groups were obviously reduced (P < 0.05, P < 0.01). Conclusion: Jinshuibao Tablets has obvious antagonistic effect on PM2.5-induced damage of rat respiratory system, and its regulation mechanism may be related to the reduction of inflammatory reactions and the delay of fibrosis progression through the PI3K/Akt signaling pathway.