Comprehensive Profiling of Antioxidant, Antidiabetic, and Cytotoxic Compounds from Morinda lucida Benth Using 1H-NMR- and UHPLC-Q Exactive Orbitrap MS-Based Metabolomics Combined with Molecular Networking and Molecular Docking.

Background/Objectives: Morinda lucida Benth is widely distributed throughout Central and West Africa. It has traditionally been used to treat and manage various diseases. However, scientific research on its phytochemical and pharmacological properties remains scarce. This study investigated the phytochemical profiles, antioxidant activities, α-glucosidase inhibitors, and cytotoxic effects of compounds derived from various parts of M. lucida. Methods: Seventy-seven natural compounds were putatively annotated using 1H-NMR, UHPLC-Q Exactive Orbitrap MS, and molecular networking techniques. The antioxidant activities of the crude extracts were assessed in vitro using DPPH free radical scavenging and reducing power assays, whereas the in vitro α-glucosidase inhibition activity and toxicity of the crude extracts were evaluated using the α-glucosidase inhibition and MTT assays. Molecular docking was used to assess the interactions between the identified glycosides and the α-glucosidase protein. Results: The root extract exhibited the highest DPPH free radical scavenging (IC50 = 7.7550 ± 6.9142 μg/mL) and reducing power capacity (IC0.5 = 0.0052 ± 0.0025 μg/mL). In contrast, the stem bark extract demonstrated significant inhibition of alpha-glucosidase (IC50 = 79.9 ± 16.1 µg/mL). Sophoricoside, formononetin 7-O-glucoside, and epicatechin identified in the stem bark extract showed notable in silico interactions with the α-glucosidase protein. The stem bark and leaf extracts were more toxic than the root extract at different concentrations. Conclusions: The results of this study demonstrate the therapeutic potential of M. lucida and provide information on its phytochemical composition and pharmacological properties.