Proteomic and metabolomic analyses reveal the antibacterial mechanism of Cannabidiol against gram-positive bacteria

Cannabidiol (CBD), the primary non-psychoactive cannabinoid isolated from cannabis, exhibits promising antibacterial effects. However, the antibacterial mechanism of CBD remains poorly understood. In this study, the mechanism was investigated using bacterial inhibition assays, label-free proteomics, and untargeted metabolomics, with Bacillus licheniformis (B. licheniformis), Staphylococcus aureus (S. aureus), and Enterococcus faecium (E. faecium) selected as representative Gram-positive bacteria. The results revealed that CBD caused significant damage to bacterial cell walls and membranes, leading to notable changes in proteomic and metabolic profiles. Specifically, 437, 120, and 195 proteins, as well as 52, 153, and 94 metabolites, were differentially expressed in B. licheniformis, S. aureus, and E. faecium, respectively. The antimicrobial mechanism of CBD shares similarities with previously known antibacterial agents, such as penicillin and cephalosporins, particularly in affecting the bacterial cell wall, but differs in its detailed mode of action. CBD disrupted the biosynthesis of primary and secondary metabolites and altered bacterial metabolism, contributing to its antibacterial activity. This study provides valuable insights into the antibacterial mechanism of CBD, supporting its potential development as an antibiotic alternative and its application in food safety. Significance: It is crucial to find alternatives to antibiotics to mitigate the impact of pathogenic bacteria on food safety and reduce the use of antibiotics. CBD is the primary non-psychoactive cannabinoid derived from cannabis, and it has shown promising antibacterial effects. However, the antimicrobial mechanisms of CBD have not been well elucidated. This study provides a deep understanding of the antibacterial mechanism from the cellular to molecular level, which will contribute to the development of CBD as a novel antibacterial agent.