Piper tuberculatum Jacq. essential oil and its impact on the control of Candida spp. and Pichia kudriavzevii: increased efficacy of fluconazole and inhibition of virulence.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper tuberculatum is a plant traditionally used in the treatment of dermatological diseases. Fungi of the genus Candida and Pichia, considered fungal pathogens with increasing resistance, are associated with cutaneous and mucocutaneous infections.

AIM OF THE STUDY: This study aimed to evaluate the essential oil extracted from P. tuberculatum fresh fruits regarding their chemical composition, antifungal and antioxidant activity, as well as their effect on the virulence and biofilm of Candida albicans, Candida tropicalis, and Pichia kudriavzevii.

MATERIALS AND

METHODS

The oil was extracted by hydrodistillation and analyzed by GC/MS. Microdilution assays determined the mean inhibitory concentration (IC50) and minimum fungicidal concentration (MFC) of the oil, fluconazole, and their combination. Morphological transition, biofilm eradication, and antioxidant activity by DPPH sequestration tests were also performed.

RESULTS

Chemically, the monoterpenes α-pinene, β-pinene, β-ocimene, nerol, and β-caryophyllene predominated. Although the oil did not present relevant clinical activity in isolation, it significantly potentiated the action of fluconazole at subinhibitory concentrations, reversing the resistance of P. kudriavzevii and other species tested. The combination showed a fungicidal effect against C. albicans and P. kudriavzevii. The oil was also effective in inhibiting virulence factors, such as the morphological transition to invasive forms and biofilm formation, reducing biomass and metabolism, mainly in C. tropicalis and P. kudriavzevii. However, it demonstrated weak antioxidant activity, with low DPPH radical scavenging.

CONCLUSIONS

Although its antioxidant potential is limited, the results corroborate the traditional use of P. tuberculatum in skin conditions and indicate its potential as an adjuvant in topical antifungal therapies, especially against resistant strains.