Antiinflammatory activity of the aqueous leaf extract of Manihot esculenta Crantz

The aqueous leaf extract of Manihot esculenta Crantz (MELE) has been used in traditional African medicine for the treatment of inflammation. The anti-inflammatory effects of MELE given through oral and topical routes, were tested in rodents. MELE (100–400mg/kg, p.o) was given to rats and 30min. later, 0.9% carrageenan was injected into the right hind paw [1]. In another set, MELE (1–4% w/w in petroleum jelly) was applied topically to either the paws or to shaved back portion of rats before carrageenan. Paw diameter was measured between 0–24h post- carrageenan injection. In another experiment, MELE (100–400mg/kg, p.o.) or (1–4% applied to mouse abdomen) was administered and 30min. later, 0.03 mL of xylene was applied to the right ear of mice; then sections of ear removed and weighed for oedema [2]. MELE (100–400mg/kg, p.o) produced significant (P <0.001) inhibition of carrageenan and xylene-induced oedema in rats and mice respectively. The percentage inhibition at 4% w/w in petroleum jelly (52.3±2.0%) is comparable to those produced by acetylsalicylic acid (50.0±2.6%). At 1–4% w/w, topically, MELE produced significant (P <0.01) inhibition of carrageenan- induced rat paw oedema (68.0±2.1%) and xylene-induced ear swelling in mice (76.6±2.2%). Effects are significantly higher than those produced by indomethacin (74.0±3.1%, 47.0±2.1%, respectively). Based on the results, the extract may contain orally safe, anti-inflammatory principles, justifying its use in folklore medicine.

References: 1. Winter, C.A. et al. (1962), Proc. Soc. Exp. Biol. 11: 533–547. 2. Tang, Xi Can, et al. (1984), Acta Pharmacol. Sinica 5: 85–89.