Antinociceptive effect of Melastoma malabathricum ethanolic extract in mice

The antinociceptive effect of the ethanolic extract of Melastoma malabathricum (NME) was investigated using acetic acid-induced abdominal writhing test and hot-plate test in mice. It was demonstrated that the extract (30-300 mg/kg, i.p.) strongly and dose-dependently inhibited the acetic acid-induced writhing with an ED50 of 100 (78-160) mg/kg i.p. It also significantly increased the response latency period to thermal stimuli. Furthermore, the nonselective opioid receptor antagonist, naloxone blocked the antinociceptive effect of the extract in both tests, suggesting that M malabathricum may act both at peripheral and central levels. (C) 2004 Elsevier B.V. All rights reserved.