Lingonberry anthocyanins protect cardiac cells from oxidative-stress-induced apoptosis

Lingonberry grown in northern Manitoba, Canada, contains exceptionally high levels of anthocyanins and other polyphenols. Previous studies from our lab have shown that lingonberry anthocyanins can protect H9c2 cells from ischemia-reperfusion injury and anthocyanin-rich diets have been shown to be associated with decreased cardiovascular disease and mortality. Oxidative stress can impair function and trigger apoptosis in cardiomyocytes. This study investigated the protective effects of physiologically relevant doses of lingonberry extracts and pure anthocyanins against hydrogen-peroxide-induced cell death. Apoptosis and necrosis were detected in H9c2 cells after hydrogen peroxide treatment via flow cytometry using FLICA 660 caspase 3/7 combined with YO-PRO-1 and then confirmed with Hoechst staining and fluorescence microscopy. Each of the 3 major anthocyanins found in lingonberry (cyanidin-3-galactoside, cyanidin-3-glucoside, and cyanidin-3-arabinoside) was protective against hydrogen-peroxide-induced apoptosis in H9c2 cells at 10 ng·mL^-1 (20 nmol·L^-1) and restored the number of viable cells to match the control group. A combination of the 3 anthocyanins was also protective and a lingonberry extract tested at 3 concentrations produced a dose-dependent protective effect. Lingonberry anthocyanins protected cardiac cells from oxidative-stress-induced apoptosis and may have cardioprotective effects as a dietary modification.