Abstract

Background and Objective: Many synthetic antioxidants are very effective but they possess some side effects and toxic properties in human health, thus warranting the increasing interest in natural antioxidants, e.g., polyphenols, present in medicinal and dietary plants. This study aimed at fractionation, determination of antioxidant properties and phytochemicals of Nauclea latifolia stem bark. Materials and Methods: Extraction was carried out using absolute ethanol in the ratio 1:5 w/v for exactly 48 hrs and elution was done with solvent combinations in order of increasing polarity, beginning from chloroform, ethyl acetate, methanol and finally water. While GC-MS analysis was carried out using a Perkin Elmer Turbo Mass Spectrophotometer (Norwalk CTO6859). The in vitro antioxidant activity, total flavonoid and total phenolic contents of seven fractions of the ethanol extract of Nauclea latifolia stem bark was determined. Results: Antioxidant activity in mg mL–1 was within the range of 50±2.52 to 95±1.16 mg mL–1. The total flavonoid concentrations varied from 100±2.00 to 190±2.65 mg mL–1 of quercetin equivalent (QE). The total phenolic content ranged from 154±2.65 to 330±3.61 mg mL–1 of gallic acid equivalents (GAE). Nauclea latifolia water fraction showed the highest antioxidant activity and total flavonoid content while the chloroform fraction has the highest total polyphenolic content. The extract of N. latifolia stem bark exhibited a strong positive correlation between the total antioxidant capacity, total flavonoids and total phenolic content (especially the methanol:water fraction). The GC-MS analysis revealed the presence of lipids, their esters and phenolic compounds. Conclusion: Hence, the plant has potential for both pharmaceutical and industrial applications. The methanol:water fraction was found to be of outstanding potential, hence, can be processed further for drug development.