Antidiarrhoeal activity of Geranium incanum Burm. f. (Geraniaceae) leaf aqueous extract in mice

Abstract

Ethnopharmacological relevance Geranium incanum Burm. f. (Geraniaceae) is used in South Africa especially in rural communities by traditional medicine practitioners to treat diarrhoea. However, scientific evidence does not exist in any literature to corroborate the claim of therapeutic success of the plant species in diarrhoea. Aim of study The study intended to investigate the antidiarrhoeal activity of the leaf aqueous extract of Geranium incanum in mice. Materials and Methods Castor oil induced diarrhoeal test was used to assess the antidiarrhoeal activity of Geranium incanum. Gastrointestinal tract transit of charcoal meal test was used to assess the antipropulsive activity of the plant extract while the acute toxicity study and phytochemical analysis were carried out using well established protocols and methods. Results The antidiarrhoeal activity of Geranium incanum was investigated by studying the effect of leaf aqueous extract of the plant species on castor oil-induced diarrhoea in mice. The leaf aqueous extract of Geranium incanum significantly reduced faecal output in castor oil -induced diarrhoea and also significantly reduced the number of diarrhoeal episodes. Geranium incanum significantly delayed the onset of diarrhoea induced by castor oil and significantly reduced the number of animals exhibiting diarrhoea. Loperamide, a standard antidiarrhoeal drug, produced similar effects to the leaf aqueous extract of Geranium incanum on castor oil-induced diarrhoea. Both Geranium incanum and loperamide significantly reduced the intestinal propulsion of charcoal meal in mice. The phytochemical analysis of the leaves revealed the presence of tannins, saponins particularly steroidal saponin, and flavonoids. The LD 50 of the plant species obtained was greater than 4000 mg/kg (p.o.). Conclusion The data obtained indicate that the leaf aqueous extract of Geranium incanum has both antidiarrhoeal and antipropulsive activities The data also show that the plant material given orally may be safe and/or non toxic in mice. However, further investigation on the acute toxicity and on the mechanism of the antidiarrhoeal effect of the plant species needs to be carried out.