Effect of intratracheal instillation of PM2.5 suspensionon pulmonary fibrosis in mice and the intervention of neotuberostemonine / 中国药科大学学报

ABSTRACT

@#To investigate the effects of intratracheal instillation of PM2.5 suspension on bleomycin (BLM)-induced pulmonary fibrosis in mice and the intervention of neotuberostemonine (NTS), the BLM dose (1.5 or 3.0 U/kg) and PM2.5 frequency (1 or 2 times per week) were studied by factorial experiment design. After intratracheal instillation of BLM (1.5 or 3.0 U/kg) on day 0, PM2.5 (5 mg/kg) was intratracheally injected to mice once or twice a week from day 1 to day 21, and the mice in the treatment group were given 30 mg/kg NTS by gavage once a day from day 8 to day 21. The degree of pulmonary fibrosis was evaluated by lung coefficient, hydroxyproline (HYP) content, HE staining and Masson staining lung sections as well as their semi-quantitative index (HE inflammatory score and collagen volume fraction, CVF). The results showed that the HE scores increased significantly in mice singly given PM2.5 once a week, the HYP content and HE score increased in mice singly given PM2.5 twice a week, but their CVF values did not significantly increase. However, the CVF values increased significantly in mice treated with PM2.5 and BLM co-infusion. These results suggested that PM2.5 (administered singly) could significantly increase BLM-induced collagen deposition and greatly aggravate pulmonary fibrosis although it mainly caused pulmonary inflammation rather than pulmonary fibrosis. NTS could significantly reduce the CVF value and α-SMA protein level of the model mice. It can be concluded that PM2.5 has great influence on patients with respiratory diseases, while NTS can improve pulmonary fibrosis induced by the combination of PM2.5 and BLM.