Phytochemical Screening and Antioxidant Properties of Morinda lucida Leaf Extracts in Edo State, South South Nigeria

Morinda lucida, locally called brimstone tree or Oruwo in Edo State, South South Nigeria, is used by traditional healers across the Benin Kingdom for treating fever, jaundice, and oxidative stress-related disorders. Despite widespread use, scientific evaluation of its antioxidant properties remains limited in this sub-region. This study screens the phytochemical composition of aqueous and methanol leaf extracts of Morinda lucida and evaluates their in vitro antioxidant activity. Leaf samples were collected from Orhionmwon and Uhunmwode local government areas, shade-dried, and extracted by cold maceration. Standard phytochemical screening methods identified the presence of alkaloids, flavonoids, tannins, anthraquinones, and phenolic acids. Antioxidant activity was assessed using DPPH and ABTS radical scavenging assays, FRAP, and total phenolic content quantification by the Folin-Ciocalteu method. The methanol extract demonstrated superior radical scavenging activity with IC50 values of 14.3 ug/mL and 11.7 ug/mL for DPPH and ABTS respectively, compared to ascorbic acid references. Total phenolic content was significantly higher in the methanol extract than the aqueous fraction. The antioxidant performance correlated positively with phenolic and flavonoid content. These findings provide pharmacological validation for the ethnomedicinal application of Morinda lucida in the management of oxidative stress-linked conditions in Edo State. Keywords: Morinda lucida, antioxidant, DPPH, phenolics, Edo State