Bioactivity assays, chemical characterization, ADMET predictions and network analysis of Khaya senegalensis A. Juss (Meliaceae) extracts

Khaya senegalensis A. Juss (Meliaceae) is a popular medicinal plant, widely used in the management of various ailments in the African traditional medicine. This study attempts to investigate into the different extraction methods (homogenizer-assisted extraction (HAE), maceration (MAC), infusion and Soxhlet (SE) extraction) on the pharmacological properties and chemical profiles of K. senegalensis. Antioxidant properties and inhibitory potential against key enzymes were assessed and bioinformatics analysis was conducted on selected limonoids to predict putative pharmacokinetics and protein targets underlying the pharmacological effects. Overall, the leaf extracts showed notable flavonoid (20.59–104.43 mg RE/g) content and the stem barks extracts displayed the highest total phenolic (87.69–46.28 mg GAE/g), phenolic acid (62.96–107.22 mg CE/g), flavanol (3.60–135.40 mg CAE/g) contents. All extracts showed remarkable antioxidant activities, with the MAC-Water leaf extract being most active in all the assays. Regarding stem bark, the MAC-MeOH extract exerted the highest free radical scavenging abilities, while HAE and MAC extracts were better sources of reducing agent and metal chelators. The HAE-MeOH, MAC-Water, and SE extracts showed noteworthy inhibitory activity against AChE, BChE (only stem barks), tyrosinase and α-glucosidase (only stem barks). All extracts displayed moderate inhibitory activities against α-amylase. The bioinformatics approach showed that khayanoside A and C interacted with multiple isoforms of metalloproteinase, while humilin B and khayanone interacted with opioid receptors. To sum up, the chemical profiles and biological activities of K. senegalensis were closely dependent on the extraction methods. Results amassed from this study showed that K. senegalensis is a potent source of bioactive compounds which could be explored as a functional food.