Abstract

The effects of aqueous extracts of Hibiscus sabdariffa l. calyces of var. ruber and var. intermedius on intestinal transit were determined in experimental rats. The dried calyces of H. sabdariffa l. were pulverized and 10% extracts of both var. ruber and var. intermedius were made and administered orally at varying doses. Test rats were given the 10% extracts of both the species of H. sabdariffa at 0.5 ml/100 g,1 ml/100 g and 2 ml/100 g body weight, while control rats received normal saline. After 30 min, each animal was then given 1.5 ml of the dye solution orally. About 1 h after administering the dye, each rat was sacrificed and the intestine carefully dissected out. The length of the intestine and the transit point of the orally administered dye were then measured. The transit point was calculated as a percentage of the total length of the intestine. The extracts of both var. ruber and var. intermedius of H. sabdariffa l. caused a reduction in transit points of the dye. The extract of var. intermediuswas more effective than var. ruber. The reduction in transit point and the increase in transit time by both extracts indicates that the plant possess astringent effect and could be used at appropriate dose as constipating agent or for stabilizing diarrhea. The acute toxicity study ofH. sabdariffa l. in rats was found to be above 5,000 mg kg^-1.

Key words: Astringent, aqueous extract, Hibiscus sabdariffa, intestinal transit, var. ruber, var. intermedius.