Prokinetic and laxative effects of the crude methanolic extract of Viola betonicifolia whole plant in rodents
1 Department of Pharmacy, University of Peshawar, Peshawar, 25120, Pakistan
2 Natural Product Research Unit, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi, 74800, Pakistan
3 Gandhara College of Pharmacy, Gandhara University, Peshawar, Pakistan
4 College of Health Sciences, Mekelle University, Mekelle, Ethiopia
BMC Complementary and Alternative Medicine 2013, 13:70 doi:10.1186/1472-6882-13-70Published: 27 March 2013
The present study was aimed to provide ethnopharmacological basis for the medicinal use of Viola betonicifolia whole plant in indigestion and constipation.
Mice were used in in-vivo prokinetic and laxative studies while in-vitro experiments were conducted on isolated tissues of rabbit and guinea-pig gut preparations suspended in a tissue bath to measure isotonic contractions.
The crude methanolic extract of Viola betonicifolia (VBME) showed partially atropine-sensitive prokinetic (50 and 100 mg/kg) and laxative (30 and 100 mg/kg) activities in mice. When tested in isolated rabbit jejunum and guinea-pig ileum, VBME caused dose-dependent contractions at 0.01-0.3 mg/mL and 0.03-5 mg/mL, respectively. The spasmogenic effect was partially sensitive to atropine, while the presence of pyrilamine, SB203186 or hexamethonium had no effect in both gut preparations. VBME partially inhibited acetylcholinesterase enzyme (19%) in the in-vitro assay. The spasmodic effect of VBME was more efficacious in guinea-pig ileum than rabbit jejunum preparation. The phytochemical analysis of the crude methanolic extract for total alkaloids and saponins revealed that the VBME is a rich source of alkaloids and saponins.
This study showed the prokinetic and laxative effects of Viola betonicifolia in mice, partially mediated through cholinergic action. The in-vitro spasmodic effect of the plant extract was also partially sensitive to atropine indicating more than one mechanisms in the gut stimulant effect. This study provides a rationale for the medicinal use of Viola betonicifolia in indigestion and constipation.