AQUEOUS ROOT BARK EXTRACT OF NAUCLEA LATIFOLIA PREVENTS INFLAMMATION AND REDUCES PAIN IN MICE

Etti, Imaobong Christopher*, Akpan, Mary Richard and Akwaowo Mfonobong

ABSTRACT

Nauclea latifolia Smith is a valuable medicinal plant used in the traditional medicine and reported to possess a wide spectrum of medicinal properties. The focus of this study was to evaluate the anti-nociceptive and anti-inflammatory properties of the aqueous root bark extract of Nauclea latifolia, in mice after determining its median lethal dose. The anti-inflammatory activity was investigated using a phlogistic agent (egg albumin) and xylene-induced ear edema, while the anti-nociceptive activity was evaluated using the acetic acid induced mouse writhing and the hot-plate test. These activities were compared to those of a standard, acetylsalicylic acid (100 mg/kg). Nauclea latifolia root bark extract (150, 299 & 449 mg/kg) inhibited xylene-induced ear edema in mice (inhibition ratio: 3.5 %, 27.6 %, and 69.0 %, respectively) and dose dependently decreased the hind paw edema with a percentage inhibition of 10 %, 63 % and 90 % respectively. There was a significant amelioration of acetic acid increased vascular permeability in mice (inhibition ratio: 47.9 %, and 72.0 %) pretreated with 299 & 449 mg/kg of the aqueous root back extract respectively. A significant increase in pain reaction time (17.5s, 44.2s) was observed in animals treated with 299 mg/kg and 449 mg/kg of the extract in the hot-plate test when compared to the control group treated with distilled water whose pain threshold was seen within 7.7 seconds. In each of the different models used, the 449 mg/kg dose of the extract showed a greater anti-inflammatory as well as anti-nociceptive effect than 100 mg/kg of acetylsalicylic acid. The Nauclea latifolia root bark extract if exploited may be a better alternative for the management of pain and inflammation.

Keywords: Nauclea latifolia, phlogistic agent.