Abstract

Neoboutonia velutina. Prain is a plant used in Cameroonian ethnomedicine for the treatment of digestive disorders such as constipation. This study was conducted to evaluate the laxative properties of aqueous and methanolic extracts of N. velutina in rats. The laxative properties as mentioned by the consulted traditional healer were firstly determined, through an evaluation of fecal emission outset, number of wet defecations, water content of faeces, ions secretion, gastrointestinal motility and intestinal fluid accumulation in an acute loperamide induced-constipation and secondly by evaluating the defecation outset, defecation frequency and water content of faeces in a pre-sub-chronic treatment. The results show that the two extracts after 08 h of observation, significantly reduced the fecal emission outset at 125 mg/kg and increased the number of wet defecations except 250 mg/kg of the aqueous extract. The methanolic extract significantly increased the fecal water content compared to the control groups. Both extracts stimulated the secretion of water and ions such as K⁺, Na⁺ and Cl^-, leading to intraluminal retention of water and an accumulation of intestinal fluid. Finally, the pre-sub-chronic treatment of constipated animals led to significant increase of fecal water content and defecations. These extracts could have laxative properties resulting from the presence of some phytoconstituents that could stimulate the increase in the fecal water content and the number of defecation. These results therefore support the traditional use of the plant in the treatment of constipation.

Key words: Neoboutonia velutina, mature stem bark, laxative properties, rats.