ACTIVE ACH-INHIBITORY FRACTIONS FROM WALTHERIA INDICA L. (STERCULIACEAE) METHANOL LEAF EXTRACT
BUNIYAMIN ADESINA AYINDE1,*, JOSEPHINE OMON OWOLABI 2 AND IFEYINWA SUZZY UTI1
1. Department of Pharmacognosy, Faculty of Pharmacy, University of Benin, Benin City, Nigeria.
2. Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Benin, Benin City, Nigeria.
Afr. J Pharm Res Dev; Volume 13(1): 026-033 (2021)
ABSTRACT
Waltheria indica is used in many medicinal preparations in ethnomedical practice in Nigeria. Its use in treating diarrhea has been scientifically validated and reported. The present work examined the probable intestinal relaxant effects of organic solvent fractions obtained from the methanol extract of the leaves. The methanol extract (90 g) was suspended in water and partitioned repeatedly with chloroform (200 mL x 5) in a separating funnel. The aqueous and the chloroform fractions were concentrated under pressure and separately evaluated for relaxant effects on 80μg Ach-induced ileum contractility at concentrations of 20, 40 and 80 mg. The aqueous fraction was further subjected to vacuum liquid chromatography (vlc) using dichloromethane with increasing concentrations of ethyl acetate and later methanol. Seven fractions obtained were tested for effects on Ach-induced ileum contractions at concentrations of 10, 20 and 40mg and compared with atropine 20 μg. Both the aqueous and dichloromethane fractions significantly (p<0.0.5) inhibited the contractile effect of Ach on the isolated ileum. However, the inhibitory effect of the aqueous fraction was more pronounced particularly at 80mg as the Cmax of Ach was reduced to 11.23 ± 1.00 % in contrast to 58.37 ± 3.16% produced by the chloroform fraction. The vlc fractions (fraction 2 and to some extent fraction 4) obtained from the aqueous fraction produced remarkable relaxant effects on the ileum particularly fraction 2 which at 20mg, completely abolished the contraction produced by the Ach, similar to the effect of Atropine (20 μg). The extract of W. indica especially the aqueous fraction contains bioactive constituents that can be separated and purified for improved relaxant effects on the intestine. The results further provide evidence for the ethno-medical use of the plant in treating diarrhea.
Email of correspondence: baayinde@uniben.edu
KEYWORDS: Waltheria indica; Aqueous fraction; Ileum contraction.