Effects of Lianhua Qingwen on Pulmonary Oxidative Lesions Induced by Fine Particulates (PM2.5) in Rats

Objective To investigate the antagonistic effects of different doses of Lianhua Qingwen on pulmonaryinjury induced by fine particulates PM2.5 in rats.Methods Fine particulates suspended in the environment were collected. Forty-eight healthy adultwistar rats were randomly divided into 6 groups with 8 rats in each group. Four groups of rats were exposedto PM2.5 by intratracheally dripping suspensions of fine particulates PM2.5 (7.5 mg/kg) as dust-exposedmodel rats. Among them 24 rats in three groups received Lianhua Qingwen treatment (crude drug) at a doseof 2 g/kg, 4 g/kg, 8 g/kg per day for 3 days before dust exposure and were defined as low-dose, middle-doseand high-dose Lianhua Qingwen treatment groups respectively. The other dust-exposed model rats withouttreatment were assigned as PM2.5 control group. The un-exposed rats were set as saline control group (1.5ml/kg saline) and blank control group. All rats were killed after 24 hours of the exposure. Lung tissue, serumand bronchoalveolar lavage fluid (BALF) were collected. The levels of malonaldehyde (MDA), lactatedehydrogenase (LDH), and glutathione peroxidase (GSH-PX) in blood serum and BALF, and superoxidedismutase (SOD) in blood surum were measured using fluorescent quantitation PCR; Expression ofNF-E2-related factor 2(NRF-2), heme oxygenase 1 (HO-1) and quinone oxidoreductase 1 (NQO1) in lungtissues were measured using Western blot. Pathological changes of lung tissues in each group were alsoexamined.