Arabica coffee extract shows antibacterial activity against Staphylococcus epidermidis and Enterococcus faecalis and low toxicity towards a human cell line

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 24h 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.