BOTANICAL CHARACTERIZATION AND PHOTOACTIVITY DIFFERENCES BETWEEN BIDENS SUBALTERNANS VAR. SUBALTERNANS AND BIDENS SUBALTERNANS VAR. SIMULANS AGAINST SPECIES OF GENUS CANDIDA

PASCUALI M.; MARIA VIRGINIA PRINCIPE; ELISA PETENATTI; GETTE M.; SORTINO M.; CARDOSO SCHIAVI P.; FUNES M.

San Luis

Congreso; XXXVII Reunión científica anual. Sociedad de Biología de Cuyo; 2020

Sociedad de Biología de Cuyo

The finding of new antimicrobial agents has become the main objective of health sciences. Because of this, search for a new therapeutic alternative for the inactivation of pathogenic microorganisms resistant to traditional chemical agents is imperative. Plants are an important source of chemical diversity providing unlimited opportunities for isolating new compounds or generating photoactive extracts with high antimicrobial potential. Although medicine has contributed to the survival of immunosuppressed patients, a high percentage died due to microbial infections. Drugs available for the treatment of superficial or systemic mycosis often show high toxicity, produce recurrence or develop resistance by pathogens. New techniques developed from photodynamic therapy could be considered according to their ability to decrease the microbial load using plant extracts already used in popular medicine. Therefore, the main objective of this work was to characterize the species Bidens subalternans var. simulans and B. subalternans var. subalternans and establish the high potential for photodynamic inactivation against yeasts. For this purpose, aerial and subterranean parts were collected and characterized. The characterization of the species allowed us to identify parameters macroand micrographics, both quali- and quantitative, applying macro-/micromorphological and taxonomic study methods to provide characters for effective quality control of raw drugs and herbal medicines containing them. The dry and ground vegetal material was extracted successively with solvents of different polarities; then the effectiveness of the extracts to inactivate yeasts of the genus Candida was observed using a microdilution assay recommended by Clinical and Laboratory Standards Institute under UVA light irradiation. It was possible to determine the high and different photoinactivation potential of extracts of B. subalternans var. simulans and B. subalternans var. subalternans. The test was performed in triplicate and the minimum concentration without microbial growth was determined visually as spectrophotometrically. Minimum inhibitory concentration (CIM100) with 100% inhibition was determined in the range of 400?1000 µg/mL for B. Subalternans var. subalternans and between 15?30 µg/mL for B. Subalternans var. simulans against different yeasts of the genus Candida. In addition, from chromatographic and spectrophotometric determinations, we have presumed that photoactive metabolites as thiophenes and polyacetylenes are present in the extracts, whose phototoxicity also appears to be related to the synergy between these components.