INSILICO EVALUATION OF NIGELLA SATIVA PHYTOCHEMICALS AS INHIBITORS OF ANOPHELES GAMBIAE ODORANT-BINDING PROTEIN (3L47)

Malaria remains one of the most severe infectious diseases in sub-Saharan Africa, with Anopheles gambiae serving as the primary vector of Plasmodium falciparum. The mosquito’s remarkable ability to detect human hosts is largely mediated by odorant-binding proteins (OBPs), which transport volatile odour molecules to olfactory receptors. Disrupting this sensory mechanism represents a promising strategy for vector control. Nigella sativa (black seed) is a medicinal plant traditionally used in African and Asian communities, known to contain bioactive phytochemicals such as thymoquinone, carvacrol, α-hederin, and nigellidine, with reported antimicrobial, antioxidant, and insecticidal activities. This study employed an in silico approach to evaluate selected N. sativa phytochemicals as potential inhibitors of Anopheles gambiae OBP (Protein Data Bank ID: 3L47). The 3D structures of phytochemicals were retrieved from PubChem, while the protein was obtained from the RCSB PDB database. Molecular docking was performed using AutoDock to assess binding affinities and interaction profiles, while pharmacokinetic and drug-likeness properties were analyzed using SwissADME and admetSAR. The results revealed that several phytochemicals displayed favourable binding energies and strong hydrogen-bond interactions with the active site residues of OBP 3L47, comparable to or exceeding those of standard control ligands. ADMET predictions indicated good oral bioavailability, low toxicity, and drug-likeness for the leading compounds. These findings suggest that N. sativa phytochemicals, particularly thymoquinone and α-hederin, hold potential as natural inhibitors of mosquito OBPs, thereby reducing host- seeking behavior and contributing to malaria vector control. The study highlights the utility of computational screening in accelerating natural product-based repellent discovery and provides a foundation for future experimental validation.