Evaluation of the analgesic activity of the ethanol extract of sungkai (Paronema canescens Jack) leaves in the albino rat

Abstract

Paronema canescens also known as sungkai, has been traditionally used for its medicinal properties, including its analgesic effects.This study aimed to determine the analgesic effect of the ethanol extract of P. canescens leaves in rats. The analgesic effect was tested with the hot plate test. The muscarinic, dopamine and opiate receptors were investigated to examine the underlying mechanism. The rats were assigned to five groups: negative control, positive control, and treatment groups 100, 200, and 400 mg/kgbody weight (BW).The mechanism of the analgesic action for each receptor (muscarinic, dopamine, and opiate) was tested with 12 rats using the dose with the highest analgesic effect as determined by the hot plate test that had been performed before. The comparison between the 100 mg/kg BW group and the positive control showed no significant differences (p > 0.05), while the 200 and 400 mg/kg BW groups were significantly different (p < 0.05). The 200 and 400 mg/kg BW groups revealed also no significant difference (p > 0.05). The ethanol extract of P. canescens leaves had the highest analgesic activity at the dose of 400 mg/kg BW with an analgesic effect of 40.26%of the pain threshold. The antinociceptive mechanism of the extract through muscarinic receptors shows an increase in latency time, while dopamine and opiate receptors show a decreased latency time. It was concluded that P. canescens leaves could contribute in the future as one of the herbal medicines to analgesics.