Determination of Phenolic Content and Antioxidant Activities of Moringa oleifera Extracts

Moringa oleifera leaves, seeds, pods, flowers, and roots have been utilized in traditional medicine and various cultural practices for centuries. In this study five different Moringa oleifera leaf extracts hexane, ethyl acetate, ethanol, methanol, and water were obtained from plant material collected in Muğla, Türkiye, in 2022. Except for the hexane extract, all samples were analyzed for their phenolic profile using HPLC-DAD. This analysis allowed for both qualitative and quantitative identification of phenolic compounds. The antioxidant activities of the extracts were evaluated by determining their IC50 values using three different in vitro assays. Based on the data obtained, the extracts demonstrated moderate antioxidant activity compared to standard reference antioxidants BHA and α-tocopherol, which served as controls with known polarities. Among the identified phenolic compounds, rutin was found to be a common constituent in all extracts. Notably, the methanol (MO4) and water (MO5) extracts exhibited a richer phenolic profile, as they contained a higher number of phenolic compounds based on the screening of 41 phenolic standards employed in the HPLC-DAD method. These findings indicate that the variation in extract polarity significantly influences both the phenolic composition and antioxidant activity of Moringa oleifera leaves. Overall, the results suggest that Moringa oleifera may serve as a potential source of natural antioxidants, with methanol and water being the most effective solvents for extracting bioactive phenolic profile.