Full Length Research Paper

Nitric oxide scavenging ability of ethyl acetate fraction of methanolic leaf extracts of Chromolaena odorata (Linn.)

Alisi, C. S and Onyeze, G. O. C

Department of Biochemistry, Federal University of Technology, Owerri, Nigeria.

*Corresponding author: E-mail: silverpresh@yahoo.com.

Accepted  22   May, 2008

   Abstract

The nitric oxide (NO^.) scavenging activities of Chromolaena odorata (Linn) King and Robinson, was investigated and compared with standard Plant Phenolic antioxidant Quercetin. Disodium pentacyanonitrosyl ferrate (2- ) dihydrate (sodium nitroprusside) was used as a nitric oxide donor. On disintegration at a physiological pH (7.2), 5 mmol/l of sodium nitroprusside generated a time dependent nitric oxide concentration which was scavenged in vitro by the extract. Inhibition of nitrite formation by Ethyl Acetate Fraction of Methanolic Extract of C. odorata (EAFCO), showed a dose-dependent response. Ability of EAFCO to scavenge nitric oxide radicals in vitro was compared to a standard Plant phenolic compound (Quercetin). Quercetin and EAFCO had IC₅₀ = 50 and 380 µg/ml respectively and an IC₁₀₀ of 2000 and 2800 µg/ml respectively. The overall result showed that the plant C. odorata is a good nitric oxide radical scavenger. The preliminary phytochemical analysis of chromolaena odorata extracts revealed the presence of alkaloids, glycosides, flavonoids, saponins and tannins. Quantitative determination of total phenolic content shows that the EAFCO contains an appreciable amount of phenolic compounds and may be responsible for the observed potential.

Key words:  Chromolaena odorata, nitric oxide scavenger, ethyl acetate fraction.