Introduction: The antimicrobial activity of essential oils (EOs) has been known for ages; in particular, the EOs of Melaleuca alternifolia, Thymus vulgaris, Mentha piperita, and Rosmarinus officinalis have been used for the treatment of fungal and bacterial infections.
Methodology: This study focused on the in vitro cytotoxicity to normal human conjunctiva cells and antimicrobial activity of 20 EOs.
Results: The oils tested showed no cytotoxic effect at very low concentrations. Rosmarinus officinalis, Melaleuca alternifolia, and Thymus vulgaris L. red thyme geraniol sel oils had good antimicrobial activity against Gram-positive and Gram-negative strains.
Conclusions: The results of this study are of great interest and may have a major impact on public health, providing useful tips to optimize the therapeutic use of some natural drugs.