Evaluation of antinociceptive effect of methanolic leaf and root extracts of Clitoria ternatea Linn. in rats

AIM: Clitoria ternatea Linn. (C. ternatea) is an Ayurvedic herb traditionally used as medicine to relieve inflammatory, rheumatism, ear diseases, fever, arthritis, eye ailments, sore throat and body ache. This study aims to evaluate and elucidate the possible mechanism underlying the antinociceptive action of methanolic extracts of C. ternatea leaf and root using several antinociception models. MATERIALS AND METHODS: The different antinociception models such as hot plate, tail-flick and formalin tests were used along with naloxone (a non-selective opioid antagonist) to establish the antinociceptive activity of both leaf and root extracts. RESULTS: Both C. ternatea leaf and root extracts markedly demonstrated antinociceptive action in experimental animals. Results of formalin test showed that the antinociceptive activity of the extracts may be mediated at both central and peripheral level. Moreover, the results of hot plate and tail-flick tests further implies that C. ternatea root extract mediates antinociceptive activity centrally at supraspinal and spinal levels whereas, the C. ternatea leaf extract's antinociceptive activity is mediated centrally at supraspinal level only. It is believed that the opioid receptors are probably involved in antinociceptive activity of both C. ternatea root extract. CONCLUSIONS: Our studies support the traditional use of C. ternatea leaf and root against pain. The extracts can also be utilised as a new source of central analgesics in treatment of pain.