Comparative anti-inflammatory and analgesic effects of fractions of Allium cepa l. bulb red cultivar extracts in rats and mice

Abstract

Pain and inflammation are amongst the most classical clinical signs of acute and chronic common diseases in humans and animals. Globally, these had led to losses of human and financial resources. This was designed to compare the anti-inflammatory and analgesic effects of four fractions of serially produced extracts of red cultivar Allium cepa L. bulbs in laboratory rats and mice. Extracts of red cultivar Allium cepa L. bulbs were serially extracted by macerating oven-dried onion bulbs in four (4) solvents (N-Hexane, Ethyl acetate, Chloroform and methanol). The anti-inflammatory and analgesic tests were carried out using Carrageenan induced paw oedema in rats and acetic acid induced abdominal writhe in mice respectively. The results revealed that while the extracts of solvents on either extremes of the polarity index (n-Hexane and methanol) were very mild in their anti-inflammatory effects, the effects of chloroform and ethyl acetate were 74.36% and 78.85% inhibition, respectively. However, the analgesic effects of all the extracts were generally low. The 50 mg/kg methanol fraction of the red cultivar A. cepa was significantly better than all the other fractions with 35% abdominal writhe inhibition in mice. This research shows that ethyl acetate fraction of the red cultivar Allium cepa extracts performed excellently as an anti-inflammatory while none of the extracts exhibited appreciable analgesic effect.