Phytochemical Screening and Antioxidant Activity of Moringa oleifera Leaf Extracts from Kano State

Moringa oleifera is widely cultivated across northern Nigeria and its leaves have been used in traditional medicine for generations, yet systematic phytochemical characterization of locally sourced material remains incomplete. This study investigates the phytochemical constituents and antioxidant capacity of leaf extracts obtained from Moringa oleifera plants grown in Kano State. Fresh leaves were collected from three communities in Kano Municipal LGA, shade-dried, and extracted sequentially using n-hexane, ethyl acetate, and methanol. Standard qualitative phytochemical screening procedures were applied to detect alkaloids, flavonoids, tannins, saponins, terpenoids, phenols, and cardiac glycosides. Quantitative determination of total phenolic content and total flavonoid content was performed using Folin-Ciocalteu and aluminium chloride colorimetric methods respectively. Antioxidant activity was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and the ferric reducing antioxidant power (FRAP) assay. Phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, saponins, and terpenoids in all three extracts, with the methanol fraction yielding the richest phenolic and flavonoid content. The methanolic extract demonstrated the highest DPPH scavenging activity with an IC50 value of 28.4 micrograms per millilitre, comparable to the ascorbic acid reference standard. These findings confirm the antioxidant potential of locally grown Moringa oleifera and support its continued use in nutritional supplementation programmes in northern Nigeria. Further toxicological and clinical studies are recommended to establish safety and efficacy profiles. Keywords: Moringa oleifera, phytochemicals, antioxidant, DPPH, Kano State.