Abstract Pain is the most common reason for physician consultation in most developed countries but treatment is becoming complex because of the side effects of analgesic pharmaceutical drugs. This has lead to an increase in the used of medicinal plants for pain and pain related conditions. Previous studies have demonstrated that Crateva adansonii stem-bark produced analgesic and anti-inflammatory effect but no data are available concerning the antinociceptive effect on the leaves. This study was aimed at investigating the antinociceptive effect of the methanolic leaves extract of C. adansonii using tail-flick and acetic acid-induced writhing methods in albino rat. The results showed that the pain reaction time (tail withdrawal) following administration of C. adansonii leaves was significantly increased (p<0.05) in a dose-dependent manner compared to the control. Also the extract at all doses caused a significant (p<0.05) dose-dependent reduction in the number of writhing when compared to the control. However, rats receiving 400mg/kg leaves extract showed no significant (p>0.05) difference in the pain reaction time and number of writhing respectively compared to the standard drug aspirin treated rats. In conclusion, C. adansonii leaves exhibited antinociceptive activity against central and peripheral mediated pain sensation. This further justifies the folkloric claim of this plant in pain treatment.
Keywords Pain, Acetic acid, antinociceptive, Aspirin, Crateva adansonii, Tail flick.