An ethanol-extract of Ampelopsis brevipedunculata (Vitaceae) berries decreases ferrous iron-stimulated hepatocyte injury in culture

Abstract

We characterized the effects of an ethanol-extract of the berries of Ampelopsis brevipedunculata (Maxim.) Trautv. (Vitaceae), a plant used in folk medicine to treat liver disease, on rat hepatocyte injury occurring spontaneously, stimulated with ferrous iron and with xanthine oxidase in combination with hypoxanthine or stimulated with ethanol in serum-free culture. Total intracellular and extracellular activities of lactate dehydrogenase (LDH) accumulating during incubation and the percentage of intracellular LDH activity released into culture medium were routinely measured, to evaluate the degree of the injury. The extract decreased a high level of LDH release spontaneously occurring and an elevated level of LDH release stimulated with ferrous iron to approximately the level caused by antioxidants, such as superoxide dismutase, pyruvate and dimethyl sulfoxide. Xanthine oxidase-stimulated LDH release was not decreased by the extract. Ethanol-stimulated LDH release was decreased by the extract when the spontaneous release level was comparatively high. These results indicate that the extract inhibits intact hepatocytes from degrading, by the toxic effect of iron released from primary injured hepatocytes through the generation of reactive oxygen species. The major antitoxic activity of the extract was found in an undialyzable fraction. Sugars were necessary to exert the activity as estimated by periodate oxidation of the extract.