Ethanolic extract of Piper betle Linn. leaves reduces nociception via modulation of arachidonic acid pathway

OBJECTIVES: The objective of this study was to evaluate the peripheral analgesic effect of Piper betle leaf extract (PBE) along with establishing its putative mechanism of action. MATERIALS AND METHODS: Male Swiss albino mice after pre-treatment (1 h) with different doses of PBE were injected 0.8% (v/v) acetic acid i.p.; the onset and number of writhes were noted up to 15 min. To evaluate the mechanism of action, the murine peritoneal exudate was incubated with PBE for 1 h, followed by exposure to arachidonic acid (AA) and generation of reactive oxygen species (ROS) was measured by flow cytometry using 2’,7’-dichlorodihydrofluorescein diacetate. RESULTS: PBE in a dose dependent manner significantly reduced acetic acid induced writhing response in mice (P < 0.001). In peritoneal exudates, PBE significantly inhibited AA induced generation of ROS, P < 0.01. CONCLUSIONS: The present study indicates that PBE has promising analgesic activity, worthy of future pharmacological consideration.