Antidiarrheal and Antimotility Activities of Stem Bark Extracts of Annona reticulata Linn. in Mice Model

Abstract

The study was aimed to evaluate the phytochemical screening, in vivo evaluation of antidiarrheal activity, and GI motility of methanolic extract as well as different organic solvent soluble fractions of bark of Annona reticulata Linn. The powdered bark of the plant was extracted with methanol using cold extraction method and fractionated with solvent-solvent partitioning using organic solvents including n-hexane, chloroform and ethyl acetate. Phytochemical screening revealed the presence of alkaloids, flavonoids, phenolic compounds, diterpenes, carbohydrate, saponins, phenols, tannins and glycosides. The different organic solvent soluble fractions of bark were evaluated at a concentration of 200 mg/kgbw in castor oil induced diarrheal mice model. The aqueous soluble fractions of bark Annona reticulata showed highest percentage of inhibition of diarrhea (64.91 ± 1.37%), whereas methanol, n-hexane, chloroform and ethyl acetate soluble fraction showed 26.99 ± 1.79%, 34.85 ± 1.66%, 52.71 ± 1.42% and 45.45 ± 1.54% of diarrheal inhibition, respectively. At the same time, the reference standard Loperamide (5 mg/kg) exhibited 73.21 ± 2.06% inhibition of diarrhea. In GI motility test by charcoal plug method, the 200 mg/kgbw of aqueous soluble fraction showed highest antimotility activity (68.71 ± 3.98%), whereas methanol, n-hexane, chloroform               and ethyl acetate soluble fractions showed 66.84 ± 3.38%, 52.01 ± 1.25%, 59.75 ± 3.56%                       and 54.70 ± 2.12% antimotility activity, respectively. The standard Loperamide (5 mg/kg) revealed 72.41 ± 1.33% inhibition of GI motility, whereas distilled water as control demonstrated 34.06 ± 1.09% of inhibition. This result  indicates that the plant extracts have a  significant inhibition of GI motility.