Photodynamic activity of Tagetes minuta extracts against superficial fungal infections

GIACONE, LUCÍA; CORDISCO, ESTEFANÍA; GARRIDO, MARÍA CLARA; PETENATTI, ELISA; SORTINO, MAXIMILIANO

MEDICAL MYCOLOGY

TAYLOR & FRANCIS LTD

Año: 2020 vol. 58 p. 797 - 809

1369-3786

Candida and dermatophyte species are the most common causes of superficial mycoses because their treatment can be difficult due to limitations of current antifungal drugs in terms of toxicity, bioavailability, interactions, narrow-spectrum activity, and development of resistance. Photodynamic therapy (PDT) involvesthe topical administration of a photosensitizer in combination with light of an appropriate wavelength andmolecular oxygen that produces reactive oxygen species (ROS), which promote damage to several vitalcomponents of the microorganism. Tagetes species are known as a source of thiophenes, biologically activecompounds whose antifungal activity is enhanced by irradiation with UVA. The present investigation evaluated Tagetes minuta extracts as a photosensitizer on growth of Candida and dermatophytes and their effecton Candida virulence factors. T. minuta root hexane and dichloromethane extracts demonstrated high photodynamic antifungal activity. Bioautographic assays and chromatographic analysis revealed the presenceof five thiophenes with reported photodynamic antifungal activities under UVA. Analysis of ROS production indicated that both type I and II reactions were involved in the activity of the extracts. In addition, theextracts inhibited virulence factors of Candida, such as adherence to epithelial surfaces and germ tube formation and showed efficacy against different Candida morphologies: budding cells, cells with germ tubeand biofilms. Results suggested that PDT with T. minuta extracts might become a valuable alternative to thealready established antifungal drugs for the treatment of superficial fungal infections.