ADME/Tox Study, Phytochemical Analysis and In Vitro Antifungal Activity of Essential Oil from Varronia curassavica Jacq. (Boraginaceae)

Abstract

Varronia curassavica Jacq. is an aromatic species appertaining to the Boraginaceae family and has been mentioned for its numerous traditional uses and pharmacological properties, especially its antimicrobial and anti-inflammatory effects. The aim of the present study was to investigate the phytochemical profile and antifungal activities of the essential oils of V. curassavica, in addition to analyzing the ADMET properties of the majority components. The GC-MS analysis of V. curassavica essential oil (EOVC) comprised 97.36% of total composition, with α-pinene, β-caryophyllene, and bicyclogermacrene (44.46%, 22.87%, and 13.05%, respectively) as the main constituents among other minor/trace constituents. The antifungal activity of EOVC was evaluated against three Candida species and was observed with IC50 > 200 μg/mL. Remarkably, the combination of EOVC with fluconazole significantly reduced the IC50 required for the drug to inhibit C. tropicalis (0.003 μg/mL), C. albicans (0.7996 μg/mL), and C. krusei (17.73 μg/mL). In addition, ADME/Tox studies using α-pinene revealed that the compound poses no toxicity threats but requires caution due to its high permeability to the blood–brain barrier (BBB). Overall, the obtained results suggest that Varronia curassavica essential oil is a potentially good antifungal agent for combating fungal resistance.