Antioxidant potentials of various solvent extracts from stem bark of Enantia chlorantha

The stem bark of Enantia chlorantha is commonly used for the treatment of malaria and other ailments of the human body such as cough and wound. The plant had been intensely studied for its antimicrobial activities and antipyretic properties. However, the efficacy and mechanisms of action of the plant remain unclear. Therefore, the objective of the present study was to determine the in vitro antioxidant activity of the various solvent extracts from stem bark of Enantia chlorantha. In vitro antioxidant activity of certain extracts of stem bark of Enantia chlorantha such as methanol extract (ME), n-hexane, chloroform, ethylacetate, and aqueous fractions (HF, CF, EF and AF respectively) was evaluated using models of DPPH radical scavenging activity, ferric reducing property (FRAP), nitric oxide scavenging activity, hydroxyl radical scavenging activity. The inhibition of lipid oxidation, total flavonoids and phenolic contents of the extracts were also determined using spectrophotometric methods. The result revealed the highest phenolic and flavonoid contents in the methanol extract followed by AF, EF and CF while HF contained the least concentration. Free radical scavenging potentials of the extracts were found to be proportional to their respective phenolic and flavonoid contents. Our results suggest that part of the mechanisms through which the plant is used in folk medicine for the treatment of stress related diseases such as malaria, and cough and wound may be through its antioxidant activity, DPPH, nitric oxide , hydroxyl radical scavenging abilities and reducing power.