Astaxanthin alleviates PM2.5-induced cardiomyocyte injury via inhibiting ferroptosis

Background: Long-term exposure of humans to air pollution is associated with an increasing risk of cardiovascular diseases (CVDs). Astaxanthin (AST), a naturally occurring red carotenoid pigment, was proved to have multiple health benefits. However, whether or not AST also exerts a protective effect on fine particulate matter (PM_2.5)-induced cardiomyocyte damage and its underlying mechanisms remain unclear.

Methods: In vitro experiments, the H9C2 cells were subjected to pretreatment with varying concentrations of AST, and then cardiomyocyte injury model induced by PM_2.5 was established. The cell viability and the ferroptosis-related proteins expression were measured in different groups. In vivo experiments, the rats were pretreated with different concentrations of AST for 21 days. Subsequently, a rat model of myocardial PM_2.5 injury was established by intratracheal instillation every other day for 1 week. The effects of AST on myocardial tissue injury caused by PM_2.5 indicating by histological, serum, and protein analyses were examined.

Results: AST significantly ameliorated PM_2.5-induced myocardial tissue injury, inflammatory cell infiltration, the release of inflammatory factors, and cardiomyocyte H9C2 cell damage. Mechanistically, AST pretreatment increased the expression of SLC7A11, GPX4 and down-regulated the expression of TfR1, FTL and FTH1 in vitro and in vivo.

Conclusions: Our study suggest that Ferroptosis plays a significant role in the pathogenesis of cardiomyocyte injury induced by PM_2.5. AST may serve as a potential therapeutic agent for mitigating cardiomyocyte injury caused by PM_2.5 through the inhibition of Ferroptosis.

Astaxanthin; Cardiomyocyte injury; Cardiovascular diseases; Ferroptosis; PM2.5.