ABSTRACT
Antioxidant and antihyperlipidemic activities of the extracts of leaves and calyces of Hibiscus sabdariffa were investigated by studying their in vitro inhibitory activity on lipid peroxidation and in vivo effects on cholesterol induced hyperlipidemia. Highest antioxidant activity was exhibited by ethanolic extract of calyces followed by ethanolic extract of leaves followed by aqueous extract of leaves of H. sabdariffa. In cholesterol induced hyperlipidemic model, groups of rats treated with extracts of calyces and leaves of H. sabdariffa showed a significant decrease in the serum TC, LDL-C, VLDL-C, TAG values alongwith an increase in serum HDL-C levels. The treated groups also showed significant decrease in the atherogenic index, LDL-C: HDL-C risk ratios, and in the levels of SGOT, SGPT and ALP activities compared to cholesterol induced hyperlipidemic control group. Significant antihyperlipidemic activity was shown by ethanolic extract of calyces, followed by ethanolic extract of leaves. It was observed from the histopathological findings that rats fed with H. sabdariffa extracts showed decrease in granular degeneration caused by cholesterol feedings. Results suggest that the ethanolic extracts of calyces and leaves of H. sabdarifa containing polyphenols and flavanols possess significant antioxidant and antihyperlipidemic activities.