Effects of aloperine on acute and inflammatory pain models in mice

Abstract

Background and objectivesAloperine (ALO) is an alkaloid compound and presents in several medicinal plants. This study was undertaken to investigate the anti-nociceptive and anti-inflammatory activities of ALO on various chemical- and thermal-induced hypersensitivity models in mice. MethodsThe anti-nociceptive effect of ALO was evaluated using acetic acid-induced writhing test, hot plate test, tail flick test, formalin test, ear swelling test, locomotor activity test, rota-rod test and carrageenan-induced paw edema test in mice. Inflammatory cytokines including interleukin-10 (IL-10), tumor necrosis factor α (TNF-α), interleukin-1 beta (IL-1β) and prostaglandin E2 (PGE2) expression were examined in ALO- and vehicle-treated mice. ResultsThe results showed that ALO significantly attenuated acetic acid-induced writhing numbers in mice in a dose-dependent manner. ALO showed no effect on prolonging latency in the hot plate test and the tail-flick test. ALO showed analgesic activity in the inflammatory phase of formalin-induced pain. Its anti-inflammatory effect was also confirmed in the ear-swelling test. In the carrageenan-induced paw edema model, ALO significantly and dose-dependently reduced the carrageenan-induced paw edema, decreased the contents of TNF-α, IL-1β and PGE2, but increased the IL-10 production. On the other hand, ALO showed no influence on the rota-rod performance time or on spontaneous locomotor activity. ConclusionIt is concluded that ALO has both anti-inflammatory and analgesic effects, especially in the field of inflammation pain. ImplicationsOur findings support the hypothesis that ALO ameliorates inflammatory pain induced by chemical and thermal stimuli and provides a scientific basis for the resource development and clinical use of aloperine.