Geraniol presents many pharmacological properties including antifungal and antibacterial activity. The objective of this study was to conduct a review of the literature concerning in vitro antimicrobial activity, anti-biofilm action, and association studies with drugs and geraniol. The study was based on a literature search from 2007 to 2019, in the databases Lilacs, Scielo, Science Direct, and PubMed. The results of 21 articles 8were selected where the most studied genera were Candida and Staphylococcus. Broth microdilution methods were the most frequently used and generally presented MIC values of ≤600 µg/mL. In the association studies, the most used technique was Checkerboard, where combinations of geraniol and standard antimicrobials were found to be synergic for most strains. Geraniol also showed antibiotic activity against the genus Staphylococcus. From our review results, it is clear that the phytoconstituent geraniol presents antimicrobial action against various species.

Mucormycoses are emerging infections that have high rates of morbidity and mortality. They show high resistance to antifungal agents, and there is a limited therapeutic arsenal currently available, therefore, there is a great need to give priority to testing therapeutic agents for the treatment of mucormycosis. Along this line, the use of essential oils and phytoconstituents has been emphasized as a new therapeutic approach. The objective of this work was to investigate the antifungal activity of the essential oil (EO) of Thymus vulgaris, and its constituents thymol and p-cymene against Rhizopus oryzae, through microbiological screening, determination of minimal inhibitory concentration (MICs) and minimal fungicidal concentration (MFCs), effects on mycelial growth and germination of sporangiospores and interaction with ergosterol. The MIC of EO and thymol varied 128–512 µg/mL, but the MFC of EO and thymol varied 512–1024 µg/mL and 128–1024 µg/mL, respectively. The results also showed that EO and thymol significantly inhibited mycelial development and germination of sporangiospores. Investigation of the mechanism of antifungal action showed that EO and thymol interact with ergosterol. These data indicate that EO of T. vulgaris and thymol possess strong antifungal activity, which can be related to their interaction with ergosterol, supporting the possible use of these products in the treatment of mucormycosis.

(2015). Antifungal activity of geraniol and citronellol, two monoterpenes alcohols, against Trichophyton rubrum involves inhibition of ergosterol biosynthesis. Pharmaceutical Biology: Vol. 53, No. 2, pp. 228-234.

Trichophyton rubrum is a worldwide agent responsible for chronic cases of dermatophytosis which have high rates of resistance to antifungal drugs. At

In this study, the minimal inhibitory concentration (MIC), minimal fungicidal concentration (MFC) and mode of action of carvacrol were determined. MIC was determined according to the standard broth microdilution method, and MFC was taken as the lowest concentration in culture plates with Sabouraud dextrose agar, at which growth was less than 3 CFU. The effect of ergosterol or sorbitol on carvacrol was investigated using the broth microdilution method. MIC was 256 μg/mL and MFC was 512 μg/mL. This phytoconstituent acts by binding to sterols in the fungal membrane and does not act by modifying the fungal cell wall. This study is important because it shows the mode of action of carvacrol. However, more studies are necessary to define the exact mechanism of action.