The protective effects of selenium supplementation on ambient PM_2.5-induced cardiovascular injury in rats

Substantial epidemiological and experimental studies have shown that ambient fine particulate matter (PM_2.5) exposure can lead to myocardial damage in human and animal through the mechanism of inflammation and oxidative stress. The purpose of the current study was to investigate whether selenium yeast (SeY) supplementation could prevent cardiovascular injury caused by PM_2.5 in rats. Fifty-six Sprague-Dawley rats were randomly divided into seven groups: saline control group; solvent control group, low-, middle-, and high-dose Se pretreatment groups, PM_2.5 exposure group, and high-dose Se control group. The rats were pretreated with different concentration of dietary SeY for 28 days, then were exposed to PM₂.₅ by intratracheal instillation every other day, a total of three times. The levels of inflammatory markers (tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), soluble intercellular adhesion molecule-1 (sICAM-1), and oxidative responses-related indicators total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) were measured in blood and myocardium of the left ventricle. The results showed that although PM_2.5 caused a decrease of T-AOC, T-AOD, and GSH-Px and increase of MDA and sICM-1, pretreatment with SeY induced a dose-dependent increase in these anti-oxidative indicators and a decrease in oxidative indicators. In addition, the levels of TNF-α and IL-1β in Se pretreatment groups were significantly lower than that in PM_2.5 exposure group. The results indicated that Se supplementation could effectively prevent cardiovascular inflammation and oxidative stress induced by PM_2.5. The results also indicated that the nutritional supplementation might be an effective way to protecting people's health from air pollution.