Evaluation of the antidiarrhoeal activity of the hydroethanolic leaf extract of Pupalia lappacea Linn. Juss. (Amaranthaceae)

Abstract

Ethnopharmacological RelevancePupalia lappacea is a medicinal plant found in savannah and woodland localities and forest path sides from Senegal to Southern Nigeria. It has been used in the management of diarrhoea in Nigerian traditional medicine. This study was designed to evaluate the antidiarrhoeal activity of the hydroethanolic leaf extract of Pupalia lappacea (PL). Materials and methodsThe antidiarrhoeal activity of PL was evaluated using the normal and castor oil-induced intestinal transit, castor oil-induced diarrhoea, gastric emptying and intestinal fluid accumulation tests in rodents. ResultsPL (100–400mg/kg, p.o.) produced a significant dose-dependent decrease in normal and castor oil-induced intestinal transit compared with the control group (distilled water 10ml/kg, p.o.). This effect was significantly (P<0.05) inhibited by pilocarpine (1mg/kg, s.c.) but not by yohimbine (10mg/kg, s.c.), prazosin (1mg/kg, s.c.), or propranolol (1mg/kg, i.p.). The extract produced a dose-dependent and significant increase in the onset of diarrhoea. PL (100–400mg/kg) also reduced the diarrhoea score, number and weight of wet stools. The in-vivo antidiarrhoeal index (ADIin vivo) of 56.95% produced by the extract at the dose of 400mg/kg was lower compared to that produced by loperamide 5mg/kg (77.75%). However, PL (400mg/kg) significantly increased gastric emptying in rats but significantly reduced the volume of intestinal content in the intestinal fluid accumulation test. Phytochemical analysis of the extract revealed the presence of alkaloids, saponins, and fixed oils and fats. The acute toxicity studies revealed that the extract is relatively safe when given orally; no death was recorded at a dose of 10g/kg. ConclusionResults showed that the hydroethanolic leaf extract of Pupalia lappacea possesses antidiarrhoeal activity possibly mediated by antimuscarinic receptor activity.