Melatonin Ameliorates Apoptosis of A549 Cells Exposed to Chicken House PM 2.5 : A Novel Insight in Poultry Production.

The particulate matter 2.5 (PM 2.5 ) from the chicken production system can cause lung injury and reduce productivity through prolonged breath as it attaches large amounts of harmful substances and microbes. Melatonin has acted to regulate physiological and metabolic disorders and improve growth performance during poultry production. This research would investigate the apoptosis caused by chicken house PM 2.5 on lung pulmonary epithelial cells and the protective action of melatonin. Here, the basal epithelial cells of human lung adenocarcinoma (A549 cells) were subjected to PM 2.5 from the broiler breeding house to investigate the apoptosis induced by PM 2.5 as well as the alleviation of melatonin. The apoptosis was aggravated by PM 2.5 (12.5 and 25 μg/mL) substantially, and the expression of Bcl-2 , Bad , Bax , PERK , and CHOP increased dramatically after PM 2.5 treatment. Additionally, the up-regulation of cleaved caspase-9 and cleaved caspase-3 as well as endoplasmic reticulum stress (ERS)-related proteins, including ATF6 and CHOP, was observed due to PM 2.5 exposure. It is worth noting that melatonin could support A549 cells' survival, in which reduced expression of Bax , Bad , cleaved caspase-3, and cleaved caspase-9 appeared. Concurrently, the level of malondialdehyde (MDA) was down-regulated and enhanced the intracellular content of total superoxide dismutase (T-SOD) and catalase (CAT) after treatment by PM 2.5 together with melatonin. Collectively, our study underlined that melatonin exerted an anti-apoptotic action on A549 cells by strengthening their antioxidant capacity.