Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Nov 25;28(23):7775.
doi: 10.3390/molecules28237775.

Azorean Black Tea (Camellia sinensis) Antidermatophytic and Fungicidal Properties

Chantal Fernandes  1   2 , José Sousa-Baptista  1   2   3 , Ana Filipa Lenha-Silva  1   2 , Daniela Calheiros  1   2   3 , Edmilson Correia  1   2 , Artur Figueirinha  4   5 , Lígia Salgueiro  4   6 , Teresa Gonçalves  1   2   3
Affiliations

Azorean Black Tea (Camellia sinensis) Antidermatophytic and Fungicidal Properties

Chantal Fernandes et al. Molecules. .

Abstract

The treatment of dermatophytoses, the most common human fungal infections, requires new alternatives. The aim of this study was to determine the antidermatophytic activity of the aqueous Azorean Black Tea extract (ABT), together with an approach to the mechanisms of action. The phytochemical analysis of ABT extract was performed by HPLC. The dermatophytes susceptibility was assessed using a broth microdilution assay; potential synergies with terbinafine and griseofulvin were evaluated by the checkerboard assay. The mechanism of action was appraised by the quantification of the fungal cell wall chitin and β-1,3-glucan, and by membrane ergosterol. The presence of ultrastructural modifications was studied by Transmission Electron Microscopy (TEM). The ABT extract contained organic and phenolic acids, flavonoids, theaflavins and alkaloids. It showed an antidermatophytic effect, with MIC values of 250 µg/mL for Trichophyton mentagrophytes, 125 µg/mL for Trichophyton rubrum and 500 µg/mL for Microsporum canis; at these concentrations, the extract was fungicidal. An additive effect of ABT in association to terbinafine on these three dermatophytes was observed. The ABT extract caused a significant reduction in β-1,3-glucan content, indicating the synthesis of this cell wall component as a possible target. The present study identifies the antidermatophytic activity of the ABT and highlights its potential to improve the effectiveness of conventional topical treatment currently used for the management of skin or mucosal fungal infections.

Keywords: Azorean Black Tea; Camellia sinensis; antidermatophytic; antifungal; cell wall; chitin; dermatophytes; ergosterol; glucan.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Effect of ABT on the cell wall β-1,3-glucan contents of T. mentagrophytes, T. rubrum and M. canis. The results, expressed in percentage in relation to control, are the means ± SEMs from three independent experiments performed in triplicates. **, p < 0.05. Data were normalized to control values.
Figure 2
Figure 2
Effect of ABT on the cell wall chitin contents of T. mentagrophytes, T. rubrum and M. canis. The results, expressed in percentage in relation to control, are the means ± SEMs from three independent experiments performed in triplicates. ***, p < 0.001. Data were normalized to control values.
Figure 3
Figure 3
Effect of ABT on the cell wall ergosterol contents of T. mentagrophytes, T. rubrum and M. canis. The results, expressed in percentage in relation to control, are the means ± SEMs from three independent experiments performed in triplicates. Data were normalized to control values.
Figure 4
Figure 4
Transmission electron microscopic observations of the hyphae morphology of T. rubrum following exposure to Azorean Black Tea. (A,B) Growth control and (C–G) with 125 μg/mL ABT. Black arrow indicates an autophagy-like vacuole.
Figure 5
Figure 5
Transmission electron microscopic (TEM) observations of the morphology of M. canis hyphae following exposure to ABT. (A) Control, in the absence of ABT and (B) with 500 μg/mL ABT. Open arrow indicates electrodense material at the cell wall surface and black arrows indicate vacuoles with debris.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Moskaluk A.E., VandeWoude S. Current Topics in Dermatophyte Classification and Clinical Diagnosis. Pathogens. 2022;11:957. doi: 10.3390/pathogens11090957. - DOI - PMC - PubMed
    1. Weitzman I., Summerbell R.C. The dermatophytes. Clin. Microbiol. Rev. 1995;8:240–259. doi: 10.1128/CMR.8.2.240. - DOI - PMC - PubMed
    1. Lipner S.R., Scher R.K. Onychomycosis: Clinical Overview and Diagnosis. J. Am. Acad. Dermatol. 2019;80:835–851. doi: 10.1016/j.jaad.2018.03.062. - DOI - PubMed
    1. Reich A., Szepietowski J.C. Healh-related quality of life in patients with nail disorders. Am. J. Clin. Dermatol. 2011;12:313–320. doi: 10.2165/11592120-000000000-00000. - DOI - PubMed
    1. Whittam L.R., Hay R.J. The impact of onychomycosis on quality of life. Clin. Exp. Dermatol. 1997;22:87–89. doi: 10.1111/j.1365-2230.1997.tb02626.x. - DOI - PubMed