Research Journal of Pharmacy and Technology

Objectives of this study were to determine the antimotility and antispasmodic effects of both methanolic and aqueous extracts of Nephelium lappaceum on contractile response induced by acetylcholine and histamine and on isolated chicken ileum. Methanolic and aqueous extracts of N. lappaceum were prepared by using maceration technique. Graded doses of acetylcholine and histamine were used to trigger the contractile response. Atropine, mepyramine and N. lappaceum extracts were used as the antagonists to reduce the intestinal contractions. Concentration response curves in the absence and in the presence of both extracts were plotted separately. Half maximal effective concentration (EC₅₀) in the presence of extracts were higher than EC₅₀ in the absence of extracts. EC₅₀ of acetylcholine in the presence of 4mg/mL and 8 mg/mL methanolic extracts were 1.59μg/mL and 1.71μg/mL respectively whereas EC50 of acetylcholine alone is 1.38μg/mL. In the presence of 2mg/mL and 4mg/mL of aqueous extracts, EC₅₀ of acetylcholine also increased to 1.98 and 2.58μg/mL respectively. EC50 of acetylcholine in the presence of 2μg/mL atropine was the lowest which was 9.84μg/mL. EC50 of histamine alone is 0.93μg/mL. After addition of 1 mg/mL and 2mg/mL methanolic extracts as well as 2mg/mL and 4 mg/mL aqueous extracts, EC50 increased to 1.08, 1.24, 1.03 and 1.09μg/mL respectively. In the presence of 2 μg/mL mepyramine, EC50 of histamine is 1.55μg/mL. In conclusion, both methanolic and aqueous extracts showed antimotility and antispasmodic properties by blocking acetylcholine and histamine.