Polyphenolic burden and in vitro antioxidant properties of Moringa oleifera root extracts

Introduction: Moringa oleifera is a small tree with very significant nutritional but also pharmacological properties and various preparations from almost all parts of the plant (leaves, fruit, stems, bark, roots) are used in folk medicine for treating several ailments. This study aimed to investigating the polyphenolic burden and in vitro antioxidant properties of M. oleifera root extracts, obtained with solvents covering a range of polarities. Methods: Lyophilised Moringa oleifera roots were extracted with solvents of increasing polarity, including ethyl acetate, butanol, methanol and water. The generated extracts were screened for polyphenolic load and antioxidant activities, by determining the total polyphenol, total flavonoid, total flavanol, antiradical activity and reducing power. Liquid chromatography-mass spectrometry was also employed to obtain some evidence regarding the nature of the main constituents. Results: The results indicated that both aqueous and methanolic extracts were the richest in total polyphenols, but the aqueous extract also exhibited high reducing power. The liquid chromatography-diode array-mass spectrometry analysis also revealed that the major substances occurring in the aqueous extract were relatively polar molecules, but the mass spectral data were ambiguous to assign tentative structures. Conclusion: Polar solvents, such as water, may be effectively used to recover high amounts of M. oleifera root phenolics, which possess important antioxidant properties