Analgesic and free radical scavenging activities of hydromethanolic extract of Crateva adansonii stem bark

BACKGROUND Crateva adansonii is a moderately sized deciduous tree found throughout the tropics especially along the river banks. This study was aimed at the evaluation of the analgesic and antioxidant activities of the methanolic extract of C. adansonii stem-bark. METHODS The analgesic activity of Crateva extract was investigated using both chemical and thermal models of nociception in rodents while the antioxidant activity was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) photometric model. RESULTS The extract produced a minute concentration-dependent increase in free radical scavenging activities. The extract (100, 200, and 400 mg/kg) caused a significant (P < 0.05) dose-dependent reduction in the number of writhing in treated rats when compared to the negative control. The extract at 100, 200, 400 mg/kg, and pentazocine (3 mg/kg) increased the pain reaction time in the treated rats by 58.05%, 66.67%, 94.76%, and 79.40%, respectively, when compared to the negative control. CONCLUSION The C. adansonii stem bark possesses analgesic activity against peripheral and central mediated pain sensation and also antioxidant properties. This study justifies the ethnomedical use of C. adansonii in pain treatment.