The Effect of Black Raspberry Extracts on MnSOD Activity in Protection Against Concanavalin A Induced Liver Injury

Abstract

Inflammation and oxidative stress are the key events in carcinogenetic transformation. Black raspberries (BRB) have been demonstrated to have antioxidant, antiinflammatory and anticancer bioactivities. In this study, a concanavalin A induced hepatitis mouse model is used to examine the effect of BRB extract on hepatic injury. Three BRB extracts, including ethanol/H₂O extracts (both anthocyanin-contained fraction and nonanthocyanin-contained fraction) and hexane extract were used. The alterations in hepatic histology, apoptosis, and oxidative stress were observed in the animals pretreated with BRB extracts and then challenged by concanavalin A. Results indicate that ethanol/H₂O extracts can inhibit Con A induced liver injury. The hepatic protection by the ethanol/H₂O BRB extracts is associated with decreases of lipid peroxidation and NDA oxidative damage. Importantly, the BRB extracts increase manganese superoxide dismutase (MnSOD) activity but not the CuZnSOD. The preservation of MnSOD by BRB extracts is associated with the protective action in the liver challenged by Con A. Ethanol/H₂O BRB extracts function as antioxidants, thus demonstrating the critical role of oxidative stress in the Con A induced liver injury, and providing evidence that the protective effects of ethanol/H₂O BRB extracts result, at least in part, from their antioxidant action.