Effects of Hibiscus Sabdariffa Calyx Extracts on 2,4-Dinitrophenylhydrazine-Induced Changes in the Activities of Antioxidant Enzymes in Rabbits

The effects of aqueous extract and anthocyanin-rich extract of the calyces of Hibiscus sabdariffa Linn 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. 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 while the level of reduced glutathione (GSH) was significantly reduced following DNPH treatment when compared to control. However, pre-treatment with (100 mg/kg body weight) whole aqueous extract of H. sabdariffa (HS) and calyx anthocyanins separately provided varying degrees of protection against DNPH-induced biochemical changes. Relative to the controls, the extracts treatments significantly (P<0.05) decreased the activities of the antioxidant enzymes. Examined separately and compared, both extracts appeared to have offered effective protection against DNPH-induced oxidative damage, though the anthocyanin isolate appeared to be more effective in this capacity. So H. sabdariffa calyx possesses potent antioxidant principles which are likely to be anthocyanins.