NITRIC OXIDE INHIBITORY ACTIVITY OF STRYCHNOS SPINOSA (LOGANIACEAE) LEAF EXTRACTS AND FRACTIONS

BACKGROUND: The study was aimed at determining the anti-inflammatory activity of fractions and extracts obtained from Strychnos spinosa leaves on a mediator of inflammation nitric oxide (NO). MATERIALS AND METHODS: Leaves were extracted with acetone and separated into fractions with different polarities by solvent-solvent fractionation. The Griess assay was used to determine the nitric oxide (NO) inhibitory activity. Cellular toxicity was determined by “using the MTT reduction assay”. RESULTS: With the exception of the ethyl acetate fraction which had an IC(50) >750 μg/mL, all extracts and fractions had significant nitric oxide-inhibitory activity. The most active being the water fraction, chloroform fraction and the dichloromethane/methanol extracts with IC(50) values of 88.43 μg/mL, 96.72 μg/mL and 115.62 μg/mL, respectively. The extracts and fractions had low cytotoxicity on macrophage U937 cell lines. CONCLUSION: Extracts and fractions of Strychnos spinosa leaves may be promising sources of natural anti-inflammatory agents. Findings obtained from this study showed that Strychnos spinosa leaves possess promising anti-inflammatory action and could be used in the treatment of inflammation-related conditions.