Blueberry treatment attenuates D-galactose-induced oxidative stress and tissue damage in rat liver

d-galactose (GAL) causes aging-related changes and oxidative stress in the organism. We investigated the effect of whole fresh blueberry (BB; Vaccinium corymbosum L.) treatment on oxidative stress in age-related liver injury model.

Rats received GAL (300 mg/kg, s.c.; 5 days per week) alone or together with 5% (BB1) and 10% (BB2) BB-containing chow for 2 months. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and hepatic malondialdehyde (MDA), protein carbonyl (PC) and glutathione (GSH) levels, and CuZn-superoxide dismutase (SOD1), glutathione peroxidase (GPx1) and glutathione transferase (GST) activities together with mRNA expressions of SOD1, GPx1, MnSOD (SOD2) and phospholipid hydroperoxide glutathione peroxidase (GPx4) were determined in GAL-treated rats.

MDA and PC levels increased, but GSH levels, SOD1 and GPx1 activities decreased together with histopathological structural damage in the liver in GAL-treated rats. There was no change in hepatic mRNA expressions of SOD2 and GPx1, but SOD1 and GPx4 expressions decreased. BB1 and BB2 caused significant decreases in serum ALT and AST activities together with the amelioration in histopathological findings in GAL-treated rats. Both BB1 and BB2 reduced MDA and PC levels, and elevated GSH levels, and SOD1 and GPx1 activities. However, hepatic mRNA expressions of SOD1, SOD2, GPx1 and GPx4 remained unchanged in GAL-treated rats.

These results show that BB restored liver pro-oxidant status together with histopathological amelioration by acting as an anti-oxidant (radical scavenger) itself without affecting mRNA expressions of anti-oxidant enzymes in GAL-treated rats.