Premium
Antimicrobial activity and mechanism of action of a thionin‐like peptide from Capsicum annuum fruits and combinatorial treatment with fluconazole against Fusarium solani
Author(s) -
Taveira Gabriel B.,
Mello Érica O.,
Carvalho André O.,
Regente Mariana,
Pinedo Marcela,
de La Canal Laura,
Rodrigues Rosana,
Gomes Valdirene M.
Publication year - 2017
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.23008
Subject(s) - fusarium solani , intracellular , mechanism of action , chemistry , growth inhibition , peptide , antimicrobial , programmed cell death , biochemistry , antimicrobial peptides , caspase , mode of action , apoptosis , microbiology and biotechnology , biology , in vitro
Many Fusarium species are able to cause severe infections in plants as well as in animals and humans. Therefore, the discovery of new antifungal agents is of paramount importance. Ca Thi belongs to the thionins, which are cationic peptides with low molecular weights (∼5 kDa) that have toxic effects against various microorganisms. Herein, we study the mechanism of action of Ca Thi and its combinatory effect with fluconazole (FLC) against Fusarium solani . The mechanism of action of Ca Thi was studied by growth inhibition, viability, plasma membrane permeabilization, ROS induction, caspase activation, localization, and DNA binding capability, as assessed with Sytox green, DAB, FITC‐VAD‐FMK, Ca Thi‐FITC, and gel shift assays. The combinatory effect of Ca Thi and FLC was assessed using a growth inhibition assay. Our results demonstrated that Ca Thi present a dose dependent activity and at the higher used concentration (50 µg mL −1 ) inhibits 83% of F. solani growth, prevents the formation of hyphae, permeabilizes membranes, induces endogenous H 2 O 2 , activates caspases, and localizes intracellularly. Ca Thi combined with FLC, at concentrations that alone do not inhibit F. solani , result in 100% death of F. solani when combined. The data presented in this study demonstrate that Ca Thi causes death of F. solani via apoptosis; an intracellular target may also be involved. Combined treatment using Ca Thi and FLC is a strong candidate for studies aimed at improved targeting of F. solani . This strategy is of particular interest because it minimizes selection of resistant microorganisms.