Verification of the folkloric diuretic claim of Hibiscus sabdariffa L. petal extract

The folklorically acclaimed diuretic activity of the petal extract of Hibiscus sabdariffa was verified in saline-loaded albino rats (80 – 220 g; n=5) according to the method of De la Peurta Vazquez et al, 1989. A methanolic extract of the dried petals was prepared, and, upon lethal toxicity testing, was found to be very safe – LD50 >5,000 mg/kg, i.p. A metabolic assay was conducted using graded doses (5 mg/kg – 160 mg/kg) The urine produced over a period of six hours was collected per animal and its volume, density, pH, and electrolyte concentrations (Na+, K+ and C-) were determined using standard techniques. The effect of the most active dose level was compared to those of frusemide 3 mg/kg, mannitol 200 mg/kg, hydrochlorothiazide 10 mg/kg, and spironolactone 3 mg/kg. The extract was found to cause a dose-dependent increase in urine mobilization, which peaked at a dose of 40 mg/kg. At this dose level, .the extract showed a significant (