The antimicrobial activity of a regular and decaffeinated Arabica coffee extract was evaluated against
three different Gram-positive bacteria and two Gram-negatives, including pathogenic Staphylococci
strains. The antimicrobial activity was shown to be independent from caffeine content and was more
pronounced against the Gram-positive strains. The regular coffee extract exhibited a significant bacteriostatic
effect against Staphylococcus aureus and Staphylococcus epidermidis at short exposure times and
became bactericidal after prolonged exposure. The potential cytotoxicity of the regular coffee extract was
also evaluated towards breast adenocarcinoma MCF7 cells, showing to become significant only after 24 h
exposure and at a higher concentration than that producing the antibacterial effect. These results
highlight the potential of coffee extracts as a naturally active and non-toxic antibacterial compound
suitable for biomedical applications.