To Evaluate and Compare the Analgesic Activity of Piperine and Extracts of Piper Nigrum L. Fruit

Narcotics (e.g., opioids) or non-narcotics (e.g., salicylates and corticosteroids) are used in the management of pain and inflammation, both of which have side effects, thereby emphasizing the search for natural substances. Piperine found naturally in plants of the Piperaceae family has shown inhibitory activity against 5-lipoxygenase and cycloxygenase-1 in in vitro studies. The present study was aimed to evaluate and compare the analgesic activity of pure compound, piperine along with hexane and ethanol extracts of Piper nigrum L. fruit in mice. The analgesic activity was determined by hot plate, tail immersion method and acetic acid induced writhing test in mice. The piperine showed great pain-relieving impact at a portion of 5 and 10 mg/kg when contrasted with control and standard. Greatest pain-relieving impact was noted at a portion of 10 mg/kg after 120 min. The hexane and ethanol remove demonstrated helpless pain-relieving impact at all dosages (5, 10 and 20 mg/kg) by hot plate method. However, with tail immersion method, piperine at a dose of 5mg/kg and ethanol extract at a dose of 20mg/kg after 120 min and hexane extract at a dose of 10mg/kg after 60min exhibited significant analgesic activity. In writhing test ethanol extract significantly stopped the number of writhes at dose of 20mg/kg while piperine at dose of 20mg/kg completely terminated the writhes in mice. It is concluded from the present study that Piper nigrum L. possesses potent analgesic activity in mice. Keywords: Piper nigrum, Piperaceae, Piperine, Hot plate, Tail immersion method, Acetic acid induced writhing test