(–)-Epicatechin Improves Vasoreactivity and Mitochondrial Respiration in Thermoneutral-Housed Wistar Rat Vasculature

Cardiovascular disease (CVD) is a global health concern. Vascular dysfunction is an aspect of CVD, and novel treatments targeting vascular physiology are necessary. In the endothelium, eNOS regulates vasodilation and mitochondrial function; both are disrupted in CVD. (–)-Epicatechin, a botanical compound known for its vasodilatory, eNOS, and mitochondrial-stimulating properties, is a potential therapy in those with CVD. We hypothesized that (–)-epicatechin would support eNOS activity and mitochondrial respiration, leading to improved vasoreactivity in a thermoneutral-derived rat model of vascular dysfunction. We housed Wistar rats at room temperature or in thermoneutral conditions for a total of 16 week and treated them with 1mg/kg body weight (–)-epicatechin for 15 day. Vasoreactivity, eNOS activity, and mitochondrial respiration were measured, in addition to the protein expression of upstream cellular signaling molecules including AMPK and CaMKII. We observed a significant improvement of vasodilation in those housed in thermoneutrality and treated with (–)-epicatechin (p < 0.05), as well as dampened mitochondrial respiration (p < 0.05). AMPK and CaMKIIα and β expression were lessened with (–)-epicatechin treatment in those housed at thermoneutrality (p < 0.05). The opposite was observed with animals housed at room temperature supplemented with (–)-epicatechin. These data illustrate a context-dependent vascular response to (–)-epicatechin, a candidate for CVD therapeutic development.