Antinociception Induced by Moringa Stenopetela (Baker f.) Cufod. Leaves Extract and Possible Mechanisms of Action

Moringa stenopetala (Baker f.) Cufod., is an endemic species growing in the south of Ethiopia. M. stenopetala is often consumed as food and used in traditional medicine and it has also been traditionally used for relieving of pain in Ethiopia. This study aimed to investigate the antinociceptive effect and mechanisms of action of M. stenopetala leaves methanol extract in mice. The per-oral doses of 50, 100, and 200 mg/kg of M. stenopetala extract were tested for antinociceptive action by using hot-plate, tail-immersion, and writhing tests. The possible mechanisms of in the antinociceptive action were investigated by pre-treatment with 5 mg/kg naloxone (non-selective opioid antagonist), 1 mg/kg ketanserin (5-HT2A/2C receptor antagonist), and 1 mg/kg yohimbine (alpha(2) adrenoceptor antagonist). The methanol extract of M. stenopetala showed antinociceptive effect in all tests. The significant involvement of 5-HT2A/2C receptors and alpha(2) adrenoceptors in antinociception induced by M. stenopetala extract in the hot-plate and tail-immersion tests, as well as significant contribution of opioid receptors and alpha(2) adrenoceptors in writhing test, were identified. In conclusion, these findings demonstrate that the methanol extract of M. stenopetala has potential in pain management. This study will contribute to new therapeutic approaches and provide guidance for new drug development studies.