title: Inhibition of chemically induced inflammation and pain by orally and topically administered leaf extract of Manihot esculenta Crantz in rodents.
abstract: The aqueous leaf extract of Manihot esculenta Crantz (MELE) is being used orally and topically in traditional African medicine for the treatment of inflammation and pain, and claimed to be safe. The anti-inflammatory effects of MELE (100-400 mg/kg, p.o. or 1-4%, w/w in petroleum jelly, topically) were tested against carrageenan-induced paw oedema in rats as well as against xylene-induced ear oedema in mice. The analgesic effect of MELE (100-400 mg/kg, p.o. or 1-4%, w/w in petroleum jelly, topically) was tested against acetic acid-induced (20 microl, 0.6%, v/v in normal saline, i.p.) and acetylcholine-induced (8.3 mg/kg, i.p.) mouse writhing models. At 100-400 mg/kg, p.o. and 1-4% (w/w), topically, MELE produced significant inhibitions of carrageenan-induced rat paw oedema and xylene-induced ear swelling in mice. Effects produced by MELE were significantly higher than those produced by indomethacin (10 mg/kg, s.c. or 1%, w/w in petroleum jelly) in the anti-inflammatory models. For the analgesic effect, MELE (100-400 mg/kg, orally) and (1-4%, w/w, topically), like aspirin (100 mg/kg, i.p.) exhibited significant (P<0.05) inhibition of acetic acid- and acetylcholine-induced mouse writhing tests, compared to untreated control. Effects produced by MELE were significantly lower than those produced by aspirin (100 mg/kg, i.p.) in the analgesic models, except for the topically administered extract on acetylcholine-induced pain. Acute oral administration up to 10 g/kg did not cause death within 14 days, but mortalities were produced in i.p. administered extract with LD(50) of 2.5+/-0.3 g/kg. Based on these, the extract may contain orally safe, topically and orally effective anti-inflammatory and analgesic principles, which justify its use in traditional African medicine.
authors.affiliation: Department of Pharmacology, College of Medicine of the University of Lagos, Idi-Araba, P.M.B. 12003 Lagos, Lagos, Nigeria. ooadey@yahoo.com
authors.forename: Olufunmilayo O
authors.initials: OO
authors.lastname: Adeyemi
authors.forename: Omoniyi K
authors.initials: OK
authors.lastname: Yemitan
authors.forename: Lateef
authors.initials: L
authors.lastname: Afolabi
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000700:Analgesics / Q000008:administration & dosage* / Q000302:isolation & purification / Q000633:toxicity; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000302:isolation & purification / Q000633:toxicity; D001241:Aspirin / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D007249:Inflammation / Q000188:drug therapy; D007928:Lethal Dose 50; D008297:Male; D002365:Manihot / Q000737:chemistry*; D016488:Medicine, African Traditional; D051379:Mice; D010146:Pain / Q000188:drug therapy; D010147:Pain Measurement; D010936:Plant Extracts / Q000008:administration & dosage* / Q000633:toxicity; D018515:Plant Leaves; D051381:Rats; D017207:Rats, Sprague-Dawley; D023382:Toxicity Tests, Acute
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents; D010936:Plant Extracts; D001241:Aspirin