Experimental and Docking Evidence for Black Seed Oil Nanoemulsion as a Natural Antimicrobial Material

Abstract

As more people use chemical preservatives and antibiotics, there is a growing need for safe, natural alternatives. It was posited that black seed oil (Nigella sativa) (BSO) and its nanoemulsion (BSO-NE) might exhibit significant antibacterial efficacy against clinically pertinent pathogens. To verify this, BSO-NE was synthesized utilizing the emulsion inversion point (EIP) technique, yielding stable nanoscale oil-in-water droplets, which were validated by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The antimicrobial activities of BSO and BSO-NE were tested against a group of Gram-positive and Gram-negative bacteria using CFU-reduction assays and agar well diffusion. BSO strongly inhibited the growth of Staphylococcus epidermidis (96.6% CFU reduction), while BSO-NE showed varying but still significant activity against the strains that were tested. To investigate the mechanism, molecular docking of thymoquinone and thymohydroquinone with ATPase demonstrated greater binding affinities compared to the reference ligand, corroborating the experimental results. These results show that BSO could be a natural antimicrobial agent and that improving NE formulations could make them work even better. The research highlights the potential of essential-oil-based nanostructures as scalable options for pharmaceutical, biomedical, and food preservation applications.