Effects of water extract of Hibiscus sabdariffa, Linn (Malvaceae) 'Roselle' on excretion of a diclofenac formulation

The effect of beverages prepared from the dried calyx of the flowers of Hibiscus sabdariffa on the excretion of diclofenac was investigated using a controlled study in healthy human volunteers. A high pressure liquid chromatographic method was used to analyse the 8 h urine samples collected after the administration of diclofenac with 300 mL (equivalent to 8.18 mg anthocyanins) of the beverage administered daily for 3 days. An unpaired two-tailed t-test was used to analyse for significant difference observed in the amount of diclofenac excreted before and after administration of the beverage. There was a reduction in the amount of diclofenac excreted and the wide variability observed in the control with the water beverage of Hibiscus sabdariffa (p < 0.05). There is an increasing need to counsel patients against the use of plant beverages with drugs.