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.
