Synergistic Hepatorenal Antioxidant Effects of Combined Aqueous Extracts of Hibiscus sabdariffa and Zingiber officinale in Streptozotocin-Administered Rats

Abstract

Streptozotocin administration causes hyperglycaemia and oxidative stress in the form of reactive oxygen species, which causes oxidative damage to hepatorenal tissues. In this study, the in vivo antioxidant potentials of combined Hibiscus sabdariffa and Zingiber officinale aqueous extracts were assessed. Lyophilized extracts were reconstituted and orally administered (400 mg/kg) at ratios of 95:5, 90:10, and 80:20 for 14 days following STZ induction (60 mg/kg). Metformin served as the reference. The results showed that superoxide dismutase activity was significantly (p < 0.05) restored from the diabetic control (liver: 0.90±0.05; kidney: 1.18±0.03) to 2.23±0.08 and 2.28±0.14 in the 80% HS + 20% ZO group. Catalase levels were markedly elevated from the diabetic baseline (liver: 4.41±0.16; kidney: 8.55±0.32) to 8.07±0.56 and 15.63±0.82 in the 80:20 treated group. Glutathione peroxidase activity improved from the untreated state (liver: 1.28±0.04; kidney: 1.30±0.05) to 2.34±0.04 and 2.50±0.10 respectively. Specific activity of Glutathione-s-peroxidase was successfully replenished from the diabetic control (liver: 0.23±0.01; kidney: 0.31±0.01) to 0.50±0.02 and 0.41±0.01 in the 80:20 group. Reduced glutathione concentrations were significantly increased (p < 0.05) over the diabetic control (liver: 62.25±0.43; kidney: 38.25±0.85) to 90.25±6.55 and 53.50±6.02. Finally, malondialdehyde levels were significantly reduced from the diabetic state (liver: 7.88±0.38; kidney: 3.55±0.15) to 2.70±0.24 and 2.52±0.30 in the 80:20 group. The findings indicate that the combined extracts exert strong hepatorenal antioxidant effects, likely mediated by synergistic phytochemicals. Assessment of liver and kidney function test are recommended to explore the hepatoprotective and nephroprotective potentials of these combined extracts.