Evaluation of in-vivo antidiarrheal activities of 80% methanol extract and solvent fractions of the leaves of Myrtus communis Linn (Myrtaceae) in mice
Creators: name: Sisay, Mekonnen
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: Evaluation of in-vivo antidiarrheal activities of 80% methanol extract and solvent fractions of the leaves of Myrtus communis Linn (Myrtaceae) in mice Mekonnen Sisay Addis Ababa University, 2015 Myrtus communis L. has a folkloric repute for the management of diarrhea and dysentery in different parts of the world including Ethiopia. However, it has not been scientifically validated yet regarding its safety and efficacy. The aim of this study was to investigate the antidiarrheal effects of both 80% methanol extract (80ME) and solvent fractions of the leaves of Myrtus communis L in mice models of diarrhea. The 80ME was obtained using maceration technique. Besides, the fractions were prepared from the leaf powder by successive soxhlet extraction with solvents of increasing polarity (chloroform followed by methanol) and then maceration of the marc of the methanol fraction with distilled water. The antidiarrheal activities of the 80ME as well as solvent fractions were evaluated using castor oil induced diarrhea, intestinal transit and enteropooling models in mice. For the 80ME, Group I served as negative control and received 10 ml/kg of distilled water orally; Group II served as a positive control and given a standard drug (3 mg/kg loperamide orally); Group III-V were test groups and received 100, 200 and 400 mg/kg of the extract respectively. A similar grouping was used for the fractions, except for the aqueous group , where they received 200, 300, 400 mg/kg with an additional dose of 800 mg/kg. In the castor oil induced diarrheal model, the 80ME significantly delayed the diarrheal onset at 200 mg/kg (p&lt;0.05) &amp; 400 mg/kg (p&lt;0.01) and inhibited the number and weight of fecal output at all tested doses. The chloroform and methanol fractions significantly delayed onset of diarrhea at 400 mg/kg (p&lt;0.05) and decreased the frequency and iv weight of fecal output (at both 300 &amp; 400 mg/kg). The aqueous fraction demonstrated modest antidiarrheal effect at 800 mg/kg (p&lt;0.05). Results from the charcoal meal test revealed that the 80ME at all doses (p&lt;0.001) as well as the chloroform and methanol fractions at 300 mg/kg (p&lt;0.05) &amp; 400 mg/kg (p&lt;0.01; p&lt;0.001) produced a significant anti-motility effect. By contrast, the aqueous fraction revealed significant antimotility effect (p&lt;0.01) at its maximum dose. Similarly, in entero-pooling test, the 80ME (at all tested doses, p&lt;0.01) as well as the chloroform and methanol fractions (at 300 &amp; 400 mg/kg, p&lt;0.05) produced a significant decline in the weight and volume of intestinal contents, whereas the aqueous fraction revealed appreciable effect (p&lt;0.05) at 800 mg/kg only. Generally, the present study demonstrated that the 80ME, chloroform and methanol fractions produced promising antidiarrheal activities due to dual inhibitory effect on castor oil induced intestinal motility and fluid secretion. Therefore, this finding provides a scientific support for acclaimed traditional use of Myrtus communis L for treatment of diarrheal diseases. Key terms: Myrtus communis, castor oil, antidiarrheal activity, antimotility, antientero-pooling, 80% methanol extract, solvent fractions