Abstract

Several researches have established the antioxidant, antibacterial and anti-inflammatory activities of the seeds and stem bark of Monodora myristica while scientific data on the pharmacological activities of the roots is sparse. Hence, this work evaluated the effects of methanol extract of the root bark of M. myristica on acute and chronic inflammation. The root bark was extracted by cold maceration in methanol to yield methanol crude extract (MME). MME was subjected to phytochemical screening and acute toxicity test. The effects of MME on acute inflammation were evaluated using carrageenan induced rat paw edema and xylene induced topical ear edema in mice. While formaldehyde induced arthritis and cotton pellet induced granuloma in rats were used to investigate its effects on chronic inflammation. The MME was found to be relatively safe (LD50 >5000 mg/kg). Phytochemical screening revealed the presence of glycosides, carbohydrates, reducing sugars, resins, terpenoids, steroid and proteins in MME. The MME elicited 58.1% inhibition of xylene induced topical ear edema and dose-dependent reduction of carrageenan induced rat paw edema with 800 mg/kg causing 60.9% inhibition after 1 to 2 h. However, there was no activity against chronic inflammation. Results demonstrate the ability of root bark of M. myristica to ameliorate acute inflammation thus justifies the ethnomedicinal use of the plant to manage inflammation. There is therefore the need for further studies on the root bark of M. myristica so as to maximize its medicinal potential.

Key words: Monodora myristica, carrageenan induced pedal edema, formaldehyde induced arthritis, cotton pellet induced granuloma, xylene induced topical ear edema, acute inflammation, chronic inflammation.