Coumaric acid analogues inhibit growth and melanin biosynthesis in Cryptococcus neoformans and potentialize amphotericin B antifungal activity

Copyright © 2020 Elsevier B.V. All rights reserved..

Fungal infections are on the rise, since the imunocompromised population is increasing due to AIDS/HIV, organ transplant and chemotherapy. Many environmental and pathogenic fungi are able to accomplish melanin biosynthesis as a virulence factor to promote host invasion. Melanized cells are more resistant to radiation, oxidative and osmotic stresses; also melanin confers an advantage in vivo, since melanized cells are more resistant to phagocytic engulfment and oxidative stress caused by the host defense cells and by some antifungal drugs, such as fluconazole (FCZ) and amphotericin B (AmB). Brown, red or black melanin pigments can be produced by the polyketide pathway (DHN-melanin) or from dihydroxyphenols, such as L-DOPA (L-3,4-dihydroxyphenylalanine) and L-tyrosine by polyphenoloxidases. Among several pathogenic fungi, Cryptococcus neoformans is a melanized yeast that causes pneumonia and meningoencephalitis in immunocompromised patients. The knockout of the laccase genes or other interruptions on melanin biosynthetic pathway generates cryptococcal strains with attenuated virulence in an animal model. In this study 16 analogues of coumaric and cinnamic acid were evaluated as possible tyrosinase inhibitors. We have identified some valuable inhibitors of C. neoformans growth and melanin biosynthesis disruption agents. The results showed that coumaric acid derivatives (1a-c), the ketones (3a-b) and 2-allylphenol (7c) are significant inhibitors of tyrosinase and melanization of the fungus. Two analogues (1b and 3b) were selected as promising antimelanogenic agents to be combined with AmB, showing to promote 16-fold reduction in the AmB fungicidal concentration with no appreciable cytotoxicity to mammalian cells. The data suggest that inhibition of the melanin biosynthesis by these compounds may increase the susceptibility of the cells to the oxidative stress generated by AmB. In summary, our data show that C. neoformans can be a suitable model system to test novel inhibitors that target melanin biosynthesis, and novel compounds for adjunct therapy against C. neoformans were identified.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:153

Enthalten in:

European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences - 153(2020) vom: 01. Okt., Seite 105473

Sprache:

Englisch

Beteiligte Personen:

Oliveira, Lidiane [VerfasserIn]
Ferrarini, Márcio [VerfasserIn]
Dos Santos, Alexandre Paes [VerfasserIn]
Varela, Marina Themoteo [VerfasserIn]
Corrêa, Isabela Teresa Santos [VerfasserIn]
Tempone, André Gustavo [VerfasserIn]
Melhem, Marcia S C [VerfasserIn]
Vallim, Marcelo A [VerfasserIn]
Fernandes, João Paulo S [VerfasserIn]
Pascon, Renata C [VerfasserIn]

Links:

Volltext

Themen:

7XU7A7DROE
Amphotericin B
Antifungal Agents
Antifungal agent
Coumaric Acids
Coumaric acid analogues
Cryptococcosis
Journal Article
Melanin
Melanins
Tyrosinase inhibitor

Anmerkungen:

Date Completed 21.06.2021

Date Revised 21.06.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.ejps.2020.105473

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM312692374