Evaluation of the antidiarrhoeal effect of Sanseviera liberica Gerome & Labroy (Agavaceae) root extract

Abstract

Ethnopharmacological relevance The aqueous root extract of Sanseviera liberica (Agavaceae), SL, is used in Traditional African Medicine (TAM) for the treatment of diarrhoea. However, the scientific basis for this usage has not been established. Aim of the study To evaluate the antidiarrhoeal activity of SL using various pharmacological models. Materials and methods The intestinal transit, castor oil induced diarrhoea, enteropooling, and gastric emptying methods were used in this study. Results SL (25–400 mg/kg, p.o.) produced significant ( P < 0.05) dose dependent reduction in propulsive movement in both the normal and castor oil induced intestinal transit tests in mice. Peak effect was elicited at 200 mg/kg but this effect was lower than that produced by morphine (10 mg/kg, s.c.). The effect of SL on castor oil induced intestinal transit was antagonized by isosorbide dinitrate, IDN (150 mg/kg, p.o.) but not by yohimbine (1 mg/kg, s.c.). In the castor oil induced diarrhoea test, SL significantly delayed the onset and decreased the frequency and severity of diarrhoea. The effect at 200 mg/kg was comparable to that of morphine and was reversed by IDN. SL at the dose of 200 mg/kg significantly reduced the volume of intestinal secretion induced by castor oil but produced no effect on gastric emptying. The extract was practically nontoxic administered p.o. The LD 50 was 631 mg/kg given i.p. Phytochemical analysis revealed the presence of oils, reducing sugars, alkaloids, saponins, anthraquinones, and tannins in the extract. Conclusion The results obtained in this study suggest that the aqueous root extract of Sanseviera liberica possesses antidiarrhoeal property due to inhibition of gastrointestinal propulsion and fluid secretion, possibly mediated through inhibition of the nitric oxide pathway. This justifies the use of the plant extract in TAM for the treatment of diarrhoea.