Hydrogen peroxide-induced modulation of intracellular oxidized states in cultured macrophage J774A.1 and neuroactive PC-12 cells, and protection by a novel grape seed proanthocyanidin extract

Abstract

We have previously compared selected antioxidants including vitamins C and E, β-carotene and a novel IH636 grape seed proanthocyanidin extract (GSPE) with respect to their scavenging abilities against biochemically generated free radicals in both in vitro and in vivo models. The results demonstrated that GSPE is a significantly more potent oxygen free radical scavenger compared with vitamins C and E and β-carotene. GSPE has been reported to exhibit a wide range of biological and pharmacological activities including free radical scavenging, antibacterial, antiviral, antiinflammatory, antiallergic and vasodilator actions. In this study hydrogen peroxide-induced oxidative damage was assessed in macrophage J774A.1 and neuroactive adrenal pheochromocytoma PC-12 cells, and the concentration-dependent ability of GSPE to protect these cells. Laser scanning confocal microscopy was used to determine intracellular oxidized states. Approximately 5.8- and 4.5-fold increases in fluorescence intensity were observed following incubation of macrophage J774A.1 and PC-12 cells with 0.50 mM H2O2 for 24 h, respectively. Pretreatment of the J774A.1 cells with 50 mg/L and 100 mg/L GSPE decreased H2O2-induced fluorescence intensity by 36% and 70%, respectively, while under these same conditions approximately 50% and 70% decreases in fluorescence intensities were observed in PC-12 cells. The results indicate that hydrogen peroxide significantly increases oxidative stress in these cells as demonstrated by the increase in intracellular oxidized states. Furthermore, GSPE can significantly protect against hydrogen peroxide-induced oxidative stress in cultured J774A.1 macrophage and neuronal PC-12 cells. Copyright © 1998 John Wiley & Sons, Ltd.