Investigation Into In-Vitro Radical Scavenging And In-Vivo Anti-Inflammatory Potential Of <i>Tridax procumbens</i>

Abstract

Tridax procumbens, is a common annual weed in the West African sub-region and other tropical zones of the world and is known as “coat buttons”. Traditional medical practitioners (TMPs) and the native peoples of these areas use the leaves of the plant as a remedy against several ailments ranging from conjunctivitis, diarrhoea, and dysentery to wound healing and related inflammatory conditions. Preliminary radical scavenging screenings proved positive and prompted further investigations into its anti-oxidant and anti-inflammatory activities. This, then necessitated the use of DPPH (2,2-diphenyl-1-picrylhydrazyl hydrate) and HET-CAM (Hen\'s egg chorioallanthoic membrane) assays to investigate the radical scavenging and anti-inflammatory potentials of the plant. The results indicated that the chloroform (CHL) and the aqueous (AQU) fractions had the highest and the lowest 50 % inhibitory concentration of free radical oxidative species (FROS) at 1.92 and 4.22μg/mL in the DPPH assay. The HET-CAM (Hen\'s eggs test on chorioallanthoic membrane) assay, a novel assay for anti-inflammatory evaluation revealed the ethylacetate (ETA) fraction as the most active: 96%: “very strong effect” in terms of restoration of an induced inflammatory condition, while the ethanol extract (ETH) showed 92%: “strong effect”. The aqueous (AQU), the Hexane (HEX) and the chloroform (CHL) fractions displayed a below 25 % inhibition. Serial dilutions of the most active fraction: the ethylacetate fraction (ETA) revealed a dose dependent trend. Chemical analysis of the whole plant showed the presence of flavonoids and alkaloids in the chloroform (CHL) and ethylacetate (ETA) fractions. Interestingly, these classes of natural products have been implicated in radical scavenging and inflammation activities in other studies and it is therefore probable that, they may be playing similar functions in Tridax procumbens and consequently would have justified its uses in traditional medical practices.

Key words: Anti-oxidant, anti-inflammatory, HET-CAM, DPPH assay, Asteraceae, Tridax procumbens.

Nigerian Journal of Physiological Sciences Vol.18(1-2) 2003: 39-43