Low concentration of anthocyanin enriched extracts from chokeberry attenuate lipid oxidation of isolated porcine coronary arteries in vitro.

Abstract

We have reported previously that impaired endothelium‐dependent, NO mediated relaxation of porcine coronary arteries, resulting from either external or internal superoxide exposure, is prevented by simultaneous exposure of the arteries to chokeberry extract ( 0.05mg total anthocyanin/L). We examined whether this concentration of extract could attenuate generalized oxidation of arterial lipids in vitro. Female porcine coronary artery rings were incubated for 1–2 days in plates of sterile tissue culture media in an O2/CO2 incubator at 37Co. Exposure of rings to exogenous superoxide by pyrogallol or endogenous superoxide by inhibition of Mg/Cu SOD, at levels shown to impair NO mediated coronary relaxation, did not result in detectable accumulation of oxidized tissue lipids as assessed by TBARS formation. Following 2 days incubation of rings in tissue culture media, oxidant stress of rings from a 2hr exposure to 250uM FeSO4+15uM ascorbic acid, shown previously to produce 40% cell toxicity, produced significant formation of arterial TBARS (0.133±0.022 vs. 0.075±0.006, mean/SEM, nmol TBARS/mg prot., n = 4, p<0.05). However, TBARS formation was reduced by 27% in rings exposed to chokeberry (0.05 mgTa/L) for 4 hrs on day 1 of incubation followed by 6 hrs on day 2. We conclude that low concentration of anthocyanin enriched chokeberry extracts, previously shown to protect arterial relaxation from oxidant impairment, also protects coronary arteries from generalized oxidation of membrane lipids. Our results suggest that such extracts may provide protection of coronary arteries from oxidant injury commonly associated with cardiovascular disease.