Pharmacological investigation of Thespesea populnea bark extract for analgesic activity

Abstract

Background: Pain is an unpleasant and distressing common problem with profound impact on individuals and society. Existing treatment modalities used for pain management are either less effective or exhibits several side effects. The aim of current study is to investigate the analgesic activity of stem bark extract of Thespesea populnea for pain management.Methods: Thirty Swiss albino were divided into five groups including control, standard and three tests groups (different doses of Thespesea populnea bark extract). Groups were investigated for analgesic activity using hot plate induced paw withdrawal, acetic acid induced writhing and formalin induced paw licking models.Results: Findings of hot plate model revealed that, percent increase in reflex latency of paw licking response in mice for test drug (10 mg/kg), attained peak effect of 136% at 180 minutes, whereas for standard pentazocine peak effect of 125% was attained at 180 minutes. In acetic acid model, the maximum percent inhibition in number of writhings for the test drug (30 mg/kg) was 68% and for standard diclofenac, it was 80%. In formalin model, percent inhibition in licking response in early and late phases for test drug (30 mg/kg) were 81% and 91% and for standard diclofenac it was 56% and 94% respectively. It was thus depicted that analgesic activity of test drug was significantly more than the standard in early phase and equivalent to standard in late phase.Conclusions: It was concluded that Thespesea populnea bark extract at a dose of 10 mg/kg showed potential peripheral and central analgesic activity.