Antifungal Activity of Black Tea Polyphenols (Catechins and Theaflavins) against Candida Species

ArticleinChemotherapy 55(3):189-96 · May 2009with448 Reads
DOI: 10.1159/000216836 · Source: PubMed
The polyphenols catechins and theaflavins in black tea have been shown to possess many medicinal properties, including anticancer activity and some antifungal characteristics, but there have been few studies of their anti-Candida activity. In this paper we report the results of our study of the anti-Candida activity of tea polyphenols. The effects of 4 different concentrations of catechins and theaflavins were evaluated on 5 isolates each of 5 Candida species employing an agar diffusion growth inhibition assay. The minimum inhibitory concentration (MIC) of the polyphenols against C. albicans was determined. The post-antifungal effect (PAFE) of the polyphenols for C. albicans was investigated. C. albicans cells exposed to polyphenols were studied using a scanning electron microscope (SEM). Both polyphenols showed anti-Candida activity against all tested Candida species and demonstrated a MIC of 6.25 mg/ml for C. albicans. C. glabrata was found to be the most sensitive species followed by C. parapsilosis, C. albicans, C. krusei and C. tropicalis (p < 0.05 for all). Significant intraspecies variations in sensitivity were noted among C. parapsilosis and C. tropicalis (p < 0.001) for both polyphenols. Theaflavins displayed standard PAFE while catechins showed a paradoxical PAFE with all isolates of C. albicans. SEM revealed considerable cell wall damage of C. albicans cells exposed to the polyphenols. The study reveals for the first time the anti-Candida properties of black tea polyphenols that may find therapeutic applications in future.
    • "Alves et al. [33] previously reported antifungal activity against species Candida of cathechin derivatives extracted from flowers of Castanea sativa, Filipendula ulmaria, Rosa micrantha and Cytius multiflorus, and from fresh leaves of Cistus ladanifer. The polyphenols (catechins and theaflavins) present in black tea also showed antifungal activity against species of Candida [34]. "
    [Show abstract] [Hide abstract] ABSTRACT: Background Medicinal plants have traditionally been used in many parts of the world as alternative medicine. Many extracts and essential oils isolated from plants have disclosed biological activity, justifying the investigation of their potential antimicrobial activity. In this study, the in vitro antifungal activity of six Brazilian Cerrado medicinal plant species were evaluated against clinically relevant Candida species. Methods The crude extract plants were evaluated against American Type Culture Collection (ATCC) standard strains of Candida spp. using disk diffusion method and determining the minimum inhibitory concentration (MIC). The chemical study results were confirmed by HPLC method. Results All six plant species showed antifungal activity. Among the species studied, Eugenia dysenterica and Pouteria ramiflora showed significant inhibitory activity against C. tropicalis at lowest MIC value of 125 and 500 μg/disc, respectively. The Eugenia dysenterica also disclosed MIC value of 125 μg/disc against C. famata, 250 μg/disc against C. krusei and 500 μg/disc against C. guilliermondii and C. parapsilosis. Pouteria torta, Bauhinia rufa, Erythroxylum daphnites and Erythroxylum subrotundum showed activity against the yeast strains with MIC value of 1000 μg/disc. The chemical study of the most bioactive extracts of Eugenia dysenterica and Pouteria ramiflora revealed catechin derivatives and flavonoids as main components. Conclusions All six evaluated plant species showed good antifungal potential against several Candida strains. However, E .dysenterica and P. ramiflora showed the higher inhibitory effect against the non-albicans Candida species. Our results may contribute to the continuing search of new natural occurring products with antifungal activity.
    Full-text · Article · Dec 2016
    • "Black tea extracts have been previously shown to be effective against S. aureus and B. cereus [3, 4, 40]. Both theaflavins and catechins have been shown to have antifungal activity against C. albicans [41] . However , the extracts tested in this study did not have an effect on C. albicans, which might be due to the phenolic content of the extracts. "
    [Show abstract] [Hide abstract] ABSTRACT: The objective of this study was to evaluate the value-added potential of black tea processing waste (BTPW) as a source of antioxidant and antimicrobial phenolic compounds. The effects of extraction solvent (water, 50 % ethanol and 80 % ethanol) and sample [different BTPW streams and black tea (BT)] and their interaction on the yield of phenolics (catechins, theaflavins and gallic acid), antioxidant and antimicrobial activity of the extracts were investigated. Total catechin (EC, EGCG, ECG) and theaflavin contents of BTPW samples were in the range of 5.2–6.0 and 11.5–16.0 mg/g DW, respectively. While catechins and theaflavins were recovered quantitatively using aqueous ethanol solvents, only 25–28 % of catechins and 6–7 % of theaflavins could be recovered in water extracts. Antioxidant activities of BTPW extracts, which were in the range of 2.23–3.59 (for DPPH), 0.59–0.92 (for FRAP) and 1.59–2.43 µmol TE/mg extract (for ABTS assay), were comparable to those of BT extracts. BTPW and BT extracts exhibited antimicrobial activity against S. aureus (1.26–3.65 mm), S. flexneri (1.33–3.89 mm) and B. cereus (1.87–3.90 mm); however, inhibition of C. albicans was not observed. BTPW can be used as a raw material for the development of value-added products with antioxidant and antimicrobial properties for applications in food, pharmaceutical, cosmetic and agricultural sectors. Aqueous ethanol solvents offer low-cost, non-toxic, green alternatives for the recovery of antioxidant and antibacterial phenolics from BTPW.
    Full-text · Article · Feb 2016
    • "The present work is the first report of the activity of proanthocyanidins polymeric tannins against fungal biofilms. However, other reports have demonstrated the antifungal the activity of flavonoid molecules against planktonic cells of yeast [32,33] and filamentous fungi [34]. Recently, Shahzad et al. [35] described the inhibitory activity of some monomeric polyphenols, including flavonoids, on planktonic cells of C. albicans and on C. albicans biofilms (at concentrations 78.12 ->1,000 μg/mL and 39.06 ->5,000 μg/mL, respectively). "
    [Show abstract] [Hide abstract] ABSTRACT: Biofilm formation is important in Candida albicans pathogenesis and constitutes a mechanism of antifungal resistance. Thus, we evaluated the effect of proanthocyanidins polymer-rich fractions from Stryphnodendron adstringens (fraction F2 and subfraction F2.4) against C. albicans biofilms. Firstly, the antifungal activity of F2 and F2.4 against planktonic cells of Candida albicans (ATCC 10231) was determined using broth microdilution method. Anti-biofilm effect of F2 and F2.4 was evaluated during biofilm formation or on mature biofilm of C. albicans and compared with standard antifungals amphotericin B and fluconazole. Metabolic activity of sessile and dispersion cells from biofilms after antifungal treatments were measured using a tetrazolium reduction assay and the biofilm total biomass was quantified by crystal violet-based assay. Morphological alterations after treatments were observed using scanning electron microscopy. The anti-biofilm effect of F2 and F2.4 were comparable to standard antifungals (amphotericin B and fluconazole). F2 and F2.4 treatments reduced biofilm metabolic activity (in sessile and in dispersion cells) during biofilm formation, and in mature biofilms, unlike fluconazole, which only prevents the biofilm formation. Treatments with F2, F2.4 or fluconazole reduced biofilm biomass during biofilm formation, but not in mature biofilm. Amphotericin B presented higher inhibitory effect on biofilm formation and on mature biofilm of C. albicans. F2 and F2.4 treatments led to the appearance of dumbbell-shaped blastoconidia and of blastoconidia clusters in biofilms. Proanthocyanidins polymer-rich fractions from S. adstringens successfully inhibited C. albicans planktonic growth and biofilm development, and they represent a potential new agent for the treatment of biofilm-associated candidiasis.
    Full-text · Article · Mar 2015
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