INVESTIGATION OF ANALGESIC ACTIVITY OF AMARANTHUS SPINOSUS LINN. (LEAVES) FROM BANGLADESH IN SWISS ALBINO MICE

The current study was aimed to investigate the analgesic activity of the methanolic extract of Amaranthus spinosus leaf (Family: Amaranthaceae). The analgesic activity was assessed with this extract for their peripheral and central anti-nociceptive potentials using three standard test methods, for instance, acetic acid induced writhing, hot plate and tail immersion methods in Swiss albino mice, at the doses of 200 and 400 mg/kg body weight. In acetic acid induced writhing method, methanolic extract of Amaranthus spinosus leaf (200 and 400 mg/kg) showed significant peripheral analgesic activity with writhing inhibition of 58.02% and 63.2% respectively whereas the standard drug diclofenac-Na (25 mg/kg) showed 73.88% writhing inhibition. In the hot plate test,  methanolic extract of the leaf (200 and 400 mg/kg body weight) showed 55.09%, and 66.22% central nociception inhibition of thermal stimulus respectively, where the standard drug morphine (5 mg/kg) displayed 50.35% nociception inhibition. In the tail immersion test, maximum 68.19% and 73.91% nociception inhibition of thermal stimulus was exhibited with methanol extract of the leaf (200 and 400 mg/kg, b.w. respectively). The methanolic extract of Amaranthus spinosus at higher dose showed more prominent central and peripheral analgesic activity. However, further investigation can also assist in inventing unexplored pharmacological activities of this plant as well as to familiarize the plant as a new source of medicine.