The natural plant compound carvacrol as an antimicrobial and anti-biofilm agent: mechanisms, synergies and bio-inspired anti-infective materials

Carvacrol (5-isopropyl-2-methyl phenol) is a natural compound that occurs in the leaves of a number of plants and herbs including wild bergamot, thyme and pepperwort, but which is most abundant in oregano. The aim of this review is to analyse the scientific data from the last five years (2012-2017) on the antimicrobial and anti-biofilm activities of carvacrol, targeting different bacteria and fungi responsible for human infectious diseases. The antimicrobial and anti-biofilm mechanisms of carvacrol and its synergies with antibiotics are illustrated. The potential of carvacrol-loaded anti-infective nanomaterials is underlined. Carvacrol shows excellent antimicrobial and anti-biofilm activities, and is a very interesting bioactive compound against fungi and a wide range of Gram-positive and Gram-negative bacteria, and being active against both planktonic and sessile human pathogens. Moreover, carvacrol lends itself to being combined with nanomaterials, thus providing an opportunity for preventing biofilm-associated infections by new bio-inspired, anti-infective materials.