Abstract

Context:Ocimum basilicum L. (Lamiaceae) has been used in folk medicine to treat headaches, kidney disorders, and intestinal worms.

Objective: This study evaluates the anti-cryptococcal activity of ethanol crude extract and hexane fraction obtained from O. basilicum var. Maria Bonita leaves.

Materials and methods: The MIC values for Cryptococcus sp. were obtained according to Clinical and Laboratory Standards Institute in a range of 0.3–2500 μg/mL. The checkerboard assay evaluated the association of the substances tested (in a range of 0.099–2500 μg/mL) with amphotericin B and O. basilicum essential oil for 48 h. The ethanol extract, hexane fraction and associations in a range of 0.3–2500 μg/mL were tested for pigmentation inhibition after 7 days of treatment. The inhibition of ergosterol synthesis and reduction of capsule size were evaluated after the treatment with ethanol extract (312 μg/mL), hexane fraction (78 μg/mL) and the combinations of essential oil + ethanol extract (78 μg/mL + 19.5 μg/mL, respectively) and essential oil + hexane fraction (39.36 μg/mL + 10 μg/mL, respectively) for 24 and 48 h, respectively.

Results: The hexane fraction presented better results than the ethanol extract, with a low MIC (156 μg/mL against C. neoformans T444 and 312 μg/mL against C. neoformans H99 serotype A and C. gattii WM779 serotype C). The combination of the ethanol extract and hexane fraction with amphotericin B and essential oil enhanced their antifungal activity, reducing the concentration of each substance needed to kill 100% of the inoculum. The substances tested were able to reduce the pigmentation, capsule size and ergosterol synthesis, which suggest they have important mechanisms of action.

Conclusions: These results provide further support for the use of ethanol extracts of O. basilicum as a potential source of antifungal agents.

Details

Title
Anti-cryptococcal activity of ethanol crude extract and hexane fraction from Ocimum basilicum var. Maria bonita: mechanisms of action and synergism with amphotericin B and Ocimum basilicum essential oil
Author
Cardoso, Nathalia N R 1   VIAFID ORCID Logo  ; Alviano, Celuta S 1 ; Blank, Arie F 2 ; Maria de Fátima Arrigoni-Blank 2 ; Romanos, Maria Teresa V 3 ; Cunha, Marcel M L 3 ; Antonio Jorge R da Silva 4 ; Alviano, Daniela S 3 

1  Department of General Microbiology, Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil;; Postgraduate Program in Plant Biotechnology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 
2  Department of Agronomy, Federal University of Sergipe, São Cristóvão, Brazil; 
3  Department of General Microbiology, Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 
4  Research Institute of Natural Products, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil 
Pages
1380-1388
Publication year
2017
Publication date
Dec 2017
Publisher
Taylor & Francis Ltd.
ISSN
13880209
e-ISSN
17445116
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1080/13880209.2017.1302483
ProQuest document ID
2195294184
Copyright
© 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This work is licensed under the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.