Evaluation of Analgesic Activity of the Methanol Extract from the Leaves of Arum palaestinum in Mice and Rats

Arum palaestinum has a wide use in traditional medicine. It used in folk medicine as a remedy for treatment of post-delivery pain, inflammation, and internal infections. The analgesic activity of the methanolic extract of Arum palaestinum was evaluated using various experimental models in mice and rats. Antinociceptive effect of methanolic extract of Arum palaestinum was carried out both peripheral and central models. The possible role of opioid receptors in analgesic activity of methanolic extract of Arum palaestinum was also examined in hot plate test using naloxone. Methanolic extract of Arum palaestinum at all three test doses (5, 10 and 20 mg/kg body weight) significantly (p < 0.05) decreased the pain response in all nociceptive models in dose-dependent fashion. Pretreatment with naloxone (2 mg/kg) caused significant (P < 0.05) change in the analgesic activity of 20 mg of methanolic extract of Arum palaestinum. In conclusion, the antinociceptive effect of methanolic extract of Arum palaestinum involves activation of peripheral (partly related to lipoxygenases and/ or cyclo-oxygenases) and central mechanism (partly, via activation of opioid receptors).