title: Psidium guajava L. and Psidium brownianum Mart ex DC.: Chemical composition and anti - Candida effect in association with fluconazole.
abstract: The therapeutic combinations have been increasingly used against fungal resistance. Natural products have been evaluated in combination with pharmaceutical drugs in the search for new components able to work together in order to neutralize the multiple resistance mechanisms found in yeasts from the genus Candida. The aqueous and hydroethanolic extracts from Psidium brownianum Mart ex DC. and Psidium guajava L. species were evaluated for their potential to change the effect of commercial pharmaceutical drugs against Candida albicans and Candida tropicalis strains. The tests were performed according to the broth microdilution method. Plate readings were carried out by spectrophotometry, and the data generated the cell viability curve and IC50 of the extracts against the yeasts. A chemical analysis of all the extracts was performed for detection and characterization of the secondary metabolites. The total phenols were quantified in gallic acid eq/g of extract (GAE/g) and the phenolic composition of the extracts was determined by HPLC. Fluconazole and all extracts presented high Minimum Inhibitories Concentrations (MICs). However, when associated with the extracts at sub-inhibitory concentrations (MIC/16), fluconazole had its effect potentiated. A synergistic effect was observed in the combination of fluconazole with Psidium brownianum extracts against all Candida strains. However, for Psidium guajava extracts the synergistic effect was produced mainly against the Candida albicans LM77 and Candida tropicalis INCQS 400042 strains. The IC50 values of fluconazole ranged from 19.22 to 68.1 μg/mL when it was used alone, but from 2.2 to 45.4 μg/mL in the presence of the extracts. The qualitative chemical characterization demonstrated the presence of phenols, flavonoids and tannins among the secondary metabolites. The concentration of total phenols ranged from 49.25 to 80.77 GAE/g in the P. brownianum extracts and from 68.06 to 82.18 GAE/g in the P. guajava extracts. Our results indicated that both P. brownianum and P. guajava extracts are effective on potentiating the effect of fluconazole, and therefore, these plants have the potential for development of new effective drugs for treating fungal infections.
authors.affiliation: Department of Biological Sciences, Regional University of Cariri, Crato, Ceará, Brazil. Electronic address: flavianamoraisb@yahoo.com.br.
authors.forename: Maria Flaviana B
authors.initials: MFB
authors.lastname: Morais-Braga
authors.affiliation: Department of Biological Chemistry, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Débora L
authors.initials: DL
authors.lastname: Sales
authors.affiliation: Department of Biological Sciences, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Joara Nalyda P
authors.initials: JNP
authors.lastname: Carneiro
authors.affiliation: Department of Biological Sciences, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Antonio Júdson T
authors.initials: AJT
authors.lastname: Machado
authors.affiliation: Department of Biological Sciences, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Antonia Thassya L
authors.initials: ATL
authors.lastname: Dos Santos
authors.affiliation: Department of Biological Chemistry, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Maria Audilene
authors.initials: MA
authors.lastname: de Freitas
authors.affiliation: Department of Biological Chemistry, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Gioconda Morais de A Bezerra
authors.initials: GMAB
authors.lastname: Martins
authors.affiliation: Department of Biological Sciences, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Nadghia Figueiredo
authors.initials: NF
authors.lastname: Leite
authors.affiliation: Department of Biological Sciences, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Yedda Maria L S
authors.initials: YMLS
authors.lastname: de Matos
authors.affiliation: Department of Biological Sciences, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Saulo R
authors.initials: SR
authors.lastname: Tintino
authors.affiliation: Federal University of the Semi Arid, Mossoró, Rio Grande do Norte, Brazil.
authors.forename: Djair S L
authors.initials: DSL
authors.lastname: Souza
authors.affiliation: Department of Biological Chemistry, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Irwin R A
authors.initials: IRA
authors.lastname: Menezes
authors.affiliation: Leão Sampaio College, Juazeiro do Norte, Ceará, Brazil.
authors.forename: Jaime
authors.initials: J
authors.lastname: Ribeiro-Filho
authors.affiliation: Department of Biological Chemistry, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: José G M
authors.initials: JGM
authors.lastname: Costa
authors.affiliation: Department of Biological Chemistry, Regional University of Cariri, Crato, Ceará, Brazil.
authors.forename: Henrique D M
authors.initials: HDM
authors.lastname: Coutinho
mesh_terms: D000935:Antifungal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects*; D041022:Candida tropicalis / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D004357:Drug Synergism; D015725:Fluconazole / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests; D064209:Phytochemicals / Q000032:analysis; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D031647:Psidium / Q000737:chemistry*; D013053:Spectrophotometry
chemical_list: D000935:Antifungal Agents; D064209:Phytochemicals; D010936:Plant Extracts; D015725:Fluconazole
keywords: Antifungal effect modulation; Phytochemical characterization; Psidium species; Yeasts