Banca de DEFESA: ALEXANDRE ABDON LEITE DANTAS

Antifungal activity and in vitro antibiofilm potential of Cannabis sativa L. against yeasts of the genus Candida

Cannabis sativa; Cannabidiol; Cannabigerol; Candida albicans; Biofilm; Antifungals.

Infections caused by yeasts of the genus Candida represent a relevant challenge in Dentistry due to the ability of these microorganisms to form biofilms, promoting infection persistence and reducing the effectiveness of conventional antifungal agents. In this context, non-psychoactive cannabinoids from Cannabis sativa L., such as cannabidiol (CBD) and cannabigerol (CBG), have attracted interest due to their antimicrobial potential and ability to modulate biofilm formation. Therefore, this study aimed to evaluate, in vitro, the antifungal and antibiofilm activities of full spectrum extracts rich in CBD and CBG, used individually and in combination, against Candida spp. strains. The strains Candida albicans (ATCC 90028), Candida tropicalis (ATCC 750), and Candida glabrata (ATCC 90030) were evaluated. The Minimum Inhibitory Concentration (MIC) was determined by the broth microdilution method using resazurin as an indicator of metabolic viability. The Minimum Fungicidal Concentration (MFC) was assessed by subculturing on solid medium, while the antibiofilm activity was analyzed using the Crystal Violet staining assay, followed by spectrophotometric absorbance reading to quantify biofilm biomass. The extracts containing CBD, CBG, and the CBD+CBG combination did not exhibit fungistatic or fungicidal activity at the evaluated concentrations, maintaining the viability of the tested strains and preventing the determination of the MFC. In contrast, nystatin demonstrated an inhibitory effect against all evaluated strains. The absence of antifungal activity may be associated with the chemical complexity of full spectrum extracts, which may interfere with the availability of free cannabinoids and, consequently, with their biological activity. Future studies involving purified cannabinoids, higher concentrations, and therapeutic combinations are needed to better elucidate the potential of these compounds.