Analgesic and anti-inflammatory studies on crude ethanol extract of <i>Cadaba farinosa</i> Forssk leaf in mice and rats

Abstract

The plant Cadaba farinosa Forssk. is used in the treatment of pains, dysentery, rheumatism, cough, and fever. Phytoconstituents include alkaloids, anthraquinones, cardiac glycosides, flavonoids, saponins and tannins. The intraperitoneal LD₅₀ of the crude ethanol leaf extract (CEE) was found to be 2154.1 mg/kg body weight in mice. The analgesic activity was investigated using acetic acid-induced writhing and hot plate tests in mice while Antiinflammation potential was investigated using carrageenan-induced hind paw oedema in rats. The extract at all the doses tested and piroxicam produced significant decrease in number of writhes at p ≤ 0.05 for extract and piroxicam compared to normal saline group. There was a significant increase (p≤ 0.01) in the pain-reaction time for thermally induced pain at 30 min of both 300 mg/kg CEE and 20 mg/kg pentazocine (standard drug). At 60 min, the significant increase (p≤ 0.05) was at 75 mg/kg CEE and 20 mg/kg pentazocine when compared to the control. The highest significant increase in mean pain reaction time for 75, 150 mg/kg CEE and pentazocine was observed at 90 min compared to the normal saline group. There was no significant difference in the mean pain latency time for thermally-induced pain between CEE and pentazocine for doses tested at 30, 60 and 120 min except for pentazocine with significant increase of p≤ 0.05 compared to the control group. There was generally a significant reduction (p ≤ 0.01) in mean paw diameter for both the extract and piroxicam treated groups compared to control group throughout the study.

Keywords: Analgesic activity, Cadaba farinosa, acetic acid, carrageenan, pain, writhes, hot plate, paw oedema