Abstrakt

Effects of Hibiscus sabdariffa calyx anthocyanins and ascorbate on 2, 4- dinitrophenylhydrazine-induced changes in the activities of antioxidant enzymes in rabbits

Augustine O Olusola

The effects of anthocyanin-rich extract of the calyces of Hibiscus sabdariffa (HS) Linn and ascorbate on the 2, 4- dinitrophenylhydrazine (DNPH)-induced changes in the levels of antioxidant enzymes of rabbits were evaluated in this study. The organs examined were the blood, brain and liver. Thirty male adult rabbits used for the study were divided into six groups. Group 1, the control took only water while animals in groups 2,3,5 and 6 received 100 mg/kg body weight of the extracts once daily for 28 days. After 22nd day of treatment, the rabbits in groups 4, 5 and 6 received 28 mg/kg body weight of DNPH for the remaining 5 days of treatment, after which the animals were sacrificed. Exposure of rabbits to DNPH (28 mg/kg body weight) caused significant (P<0.05) increase in catalase and superoxide dismutase activities relative to the DNPH-free group. The activity of glucose-6-phosphate dehydrogenase was also significantly (p<0.05) elevated in the serum following DNPH treatment when compared to control. However, pre-treatment with (100 mg/kg body weight) HS anthocyanins and ascorbate separately provided varying degrees of protection against DNPH-induced biochemical changes. Relative to the controls, the extract and ascorbate treatments significantly (P<0.05) decreased the activities of the antioxidant enzymes. Examined separately and compared, both treatments appeared to have offered effective protection against DNPH-induced oxidative damage, though the anthocyanin isolate appeared to be more effective in this capacity. Our findings show that Hibiscus sabdariffa anthocyanins are probably more potent antioxidants than ascorbate.