The novel antioxidant ergothioneine found in dietary mushrooms inhibits monocyte binding to human aortic endothelial cells

Abstract

Cardiovascular disease (CVD) is a leading cause of mortality in the United States. An accumulating body of evidence suggests that dietary consumption of fruits and vegetables can reduce CVD risk via a plethora of bioactive agents functioning, in part, as antioxidants since oxidative stress is considered an early feature of atherogenesis. In this study, we focused on the naturally occurring metabolite ergothioneine (ERT) found in dietary mushrooms because of its demonstrated antioxidant capacity in mammalian cells. ERT is present in edible mushrooms and is not synthesized, but is accumulated, by humans through diet. In this study, human aortic endothelial cells (HAEC) were incubated overnight (20 h) with increasing concentrations of ERT (0.01–10.0 mM) followed by incubation, after washing, with medium alone or with the pro‐inflammatory cytokine IL‐1beta (5 ng/mL) for 6 h. ERT at concentrations of 0.1–0.3 mM significantly (p < 0.05) reduced VCAM‐1, ICAM‐1, and E‐selectin adhesion molecule (AM) expression maximally by 41%. Binding of U937 human monocytes to HAEC was significantly reduced both in unstimulated monolayers and by 12‐27% in IL‐1beta‐stimulated HAEC pre‐incubated with 1 and 3 mM ERT, respectively. Viability was not different between treatments. These data provide evidence that ERT found in dietary mushrooms can protect against atherogenesis by reducing AM expression and subsequent monocyte binding.