Sesamin Ameliorates Fine Particulate Matter (PM2.5)-Induced Lung Injury via Suppression of Apoptosis and Autophagy in Rats

Lung damage can be caused by fine particulate matter (PM2.5). Thus, effective prevention strategies for PM2.5-induced lung injury are urgently required. Sesamin (Ses) is a natural polyphenolic compound that has attracted considerable attention of researchers because of its wide range of pharmacological activities. The present study aims to elucidate whether Ses pretreatment could alleviate PM2.5-induced lung damage and identify its possible mechanisms. Sprague-Dawley rats were orally dosed with 0.5% carboxymethylcellulose (CMC) and different concentrations of Ses once a day for 21 days. Then, the rats of the PM2.5 exposure group and Ses-treated group were exposed to PM2.5 by intratracheal instillation every 2 days for 1 week. Biomarkers associated with lung injury were detected in bronchoalveolar lavage fluid (BALF). Lung tissue was collected for histology, inflammation, oxidative stress, immunohistochemistry, and Western blot. Our results showed that PM2.5 exposure could cause pathological changes in lung tissue and increase levels of TP, AKP, and ALB in BALF. Meanwhile, exposure to PM2.5 can cause oxidative stress and inflammation in the lungs. In addition, Ses pretreatment could ameliorate histopathological injury, oxidative stress, and inflammation caused by PM2.5 exposure. It could also inhibit PM2.5-induced apoptosis and upregulation of autophagy-associated proteins. Collectively, our study indicated that Ses pretreatment could ameliorate PM2.5-induced lung damage via inhibiting apoptosis and autophagy in rats.