Halicin: A New Approach to Antibacterial Therapy, a Promising Avenue for the Post-Antibiotic Era

Background: The global spread of antibiotic-resistant bacteria presents a major public health challenge and necessitates the development of innovative antimicrobial agents. Artificial intelligence (AI)-driven drug discovery has recently enabled the repurposing of existing compounds with novel therapeutic potential. Halicin, originally developed as an anti-diabetic molecule, has been identified through AI screening as a promising antibiotic candidate due to its broad-spectrum activity, including efficacy against multidrug-resistant pathogens. Methods: In this study, the antibacterial activity of halicin was evaluated against a range of clinically relevant multidrug-resistant bacterial strains. Bacterial isolates were first characterized using the agar disk diffusion method with a panel of 22 conventional antibiotics to confirm resistance profiles. The minimum inhibitory concentration (MIC) of halicin was then determined for selected isolates, including Escherichia coli ATCC^® 25922™ and Staphylococcus aureus ATCC^® 29213™, using broth microdilution according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Halicin demonstrated notable antibacterial activity, with MIC values of 16 μg/mL and 32 μg/mL against E. coli ATCC^® 25922™ and S. aureus ATCC^® 29213™, respectively. A dose-dependent inhibition of bacterial growth was observed for the majority of tested isolates, except for Pseudomonas aeruginosa, which exhibited intrinsic resistance. This lack of susceptibility is likely related to reduced outer membrane permeability, limiting the intracellular accumulation of halicin. Conclusions: Our findings support the potential of halicin as a novel antimicrobial agent for the treatment of infections caused by antibiotic-resistant bacteria. However, further investigations, including pharmacokinetic, pharmacodynamic, and toxicity studies, are essential to assess its clinical safety and therapeutic applicability.