Effects of aqueous extracts of petals of red and green Hibiscus sabdariffa on plasma lipid and hematological variables in rats

Abstract

The effects of administrating aqueous extracts of the petals of red and green Hibiscus sabdariffa (1.0 and 1.5 mg/kg body weight) on hematological and plasma lipid variables were examined in rats. Animals were randomly divided into group A (control), groups B and C (treated with 1.0 and 1.5 mg/kg body weight, respectively, of the extract of petals of red Hibiscus sabdariffa), and groups D and E (treated with 1.0 and 1.5 mg/kg body weight, respectively, of the extract of petals of green Hibiscus sabdariffa). The chronic administration of both extracts for 28 days resulted in significant decreases in the plasma total cholesterol levels at 1.5 mg/kg body weight (p < 0.05) while the extracts led to significant decreases in LDL-cholesterol levels at both 1.0 and 1.5 mg/kg body weight only (p < 0.05). In contrast, the administration of the extracts did not have any significant effect on HDL-cholesterol, triglycerides, hematocrit, hemoglobin, red blood cell count, white blood cell count, and platelet count values when compared with the controls (p > 0.05). These results indicate that the lowered plasma total cholesterol concentrations induced by aqueous extracts of either red or green Hibiscus sabdariffa petals is strongly associated with decreased LDL-cholesterol concentrations. Thus, both extracts could exert similar cardiovascular protective effects. © 2005 Taylor & Francis Ltd.