Antinociceptive and Anti-Inflammatory Activities of Ethanolic Stem Bark Extract of Smilax zeylanica Linn. in Wistar Rats

Abstract

Background: Smilax zeylanica Linn (Smilaceae) is a woody climbing shrub native to Asia's tropical and subtropical highlands. Traditionally, this plant has been widely used to cure a variety of ailments. Smilax zeylanica stem bark was extracted with ethanol to test its antinociceptive and anti-inflammatory properties. Objective: To study the antinociceptive and anti-inflammatory activities of ethanolic stem bark extract of Smilax zeylanica Linn. in Wistar rats. Methods: The antinociceptive activity has been assessed in mice by formalin-induced paw licking, Eddy’s hot-plate, and acetic-acid induced abdominal stretching models. Carrageenan-induced paw oedema in rats has been conducted to explore the anti-inflammatory activity. Tween 80 (10ml/kg, p.o) was given to the control group, test drug group received ethanol extract of Smilax zeylanica (EESZ) orally at doses of 200 and 400 mg/kg, and standard drugs morphine (5 mg/kg, s.c), diclofenac sodium (10 mg/kg, i.p) were injected to the standard drug group. Results: Oral administration of ethanolic extract of Smilax zeylanica (EESZ) at test doses (200 and 400 mg/kg), produced a significant decrease of the paw licking time for 2 phases (neurogenic and inflammatory) in the formalin test, upsurge of the reaction time in Eddy’s hot plate test, and significantly decreased the abdominal stretching in the acetic acid-induced  writhes test. Ethanol extract of Smilax zeylanica significantly decreased the carrageenan-induced paw oedema. Conclusion: The ethanol extract of Smilax zeylanica possesses antinociceptive, anti-inflammatory activity, probably involving central and peripheral pathways