Antibiofilm Activity and Mechanism of Action of the Disinfectant Chloramine T on Candida spp., and Its Toxicity against Human Cells.

We evaluated the antifungal and anti-biofilm activity, mechanism of action and cytotoxicity of chloramine T trihydrate (CAT) against Candida spp. The Minimum Inhibitory and Fungicidal Concentrations (MIC/MFC) of CAT were determined. Changes in CAT-treated C. albicans growth kinetics and micromorphology were evaluated, as well as the mechanism of action, and its effects on biofilm. Cytotoxicity was assessed by the hemolysis method. The data were analyzed by inferential statistics (p ≤ 0.05). CAT showed antifungal activity against all strains, with MIC values ranging between 1.38 and 5.54 mmol/L (MIC75%: 2.77 mmol/L). CAT demonstrated an immediate and sustained action on C. albicans growth kinetics, particularly at 2 × MIC. This compound likely acts on the cell wall and membrane permeability simultaneously and was found to cause changes in C. albicans micromorphology. Tha antibiofilm activity of CAT was similar to that of sodium hypochlorite (p > 0.05) against mature biofilms. CAT was more effective than NaOCl in reducing mature biofilm upon 1-min exposure at 2 × MIC (24 h) and 4 × MIC (48 h) (p < 0.05). Toxicological analysis revealed that CAT had hemolytic activity between 61 and 67.7% as compared to 100% by NaOCl. CAT has antifungal and anti-biofilm properties, probably acting on both cell wall and membrane permeability, and showed low toxicity in vitro.

Study of the antifungal potential of (r)-(+)-citronellal and its association with therapeutic agents used in the treatment of vulvovaginal candidiasis / Estudo do potencial antifúngico do (r)-(+)-citronelal e sua associação com agentes terapêuticos utilizados no tratamento da candidíase vulvovaginal

Vulvovaginal candidiasis (VVC) is a common fungal infection that affects healthy women of all ages. At least 75% of women will develop one or more infections once during their lifetime, with 6 to 9% of those individuals developing recurrent infections. In view of this context, this study sought to evaluate the antifungal potential of the isolated (R)-(+)-citronellal [(R)-(+)-CT] and associated to therapeutic agents of clinical importance. The enantiomer was solubilized in tween 80 and dimethylsulfoxide (DMSO). Posteriorly diluted in sterile distilled water up to the concentration of 2048µg/mL. The minimum inhibitory concentration (MIC) of the product was determined by microdilution in RPMI-1640 obtaining dilutions of 1024-4µg/mL. The minimum fungicidal concentration (MFC) was determined by the Sabouraud dextrose agar (SDA) depletion technique from aliquots of 1µL of the MIC, MIC × 2 and MIC × 4. The MIC and the MFC values of (R)-(+)-CT for 90% of the C. albicans strains were 16 and 32µg/mL respectively. In the susceptibility test, C. albicans presented a high resistance to fluconazole and to itraconazole, 12 (92.30%) of the strains. However, for ketoconazole and miconazole the resistance was of 4 (30.76%) and 3 (23.07%) of the strains respectively. In the combination testing of the (R)-(+)-CT with ketoconazole and miconazole, the resistance was completely reverted. For fluconazole and itraconazole, the resistance was reverted in 9 (75%) and 7 (58.33%) of the strains respectively. The (R)-(+)-CT presented fungicide activity with MFC of MIC × 2. When in combination with ketoconazole, fluconazole, itraconazole and miconazole increased the inhibition zones of these antifungal drugs, reducing the resistance against C. albicans.

Candidíase vulvovaginal (CVV) é uma infecção fúngica comum que afeta mulheres saudáveis de todas as idades. Pelo menos 75% das mulheres irão desenvolver uma ou mais infecções uma vez durante a vida, com 6 a 9% dos indivíduos desenvolvendo infecções recorrentes. Diante deste contexto, buscou-se avaliar neste estudo o potencial antifúngico do (R)-(+)-citronelal [(R)-(+)-CT] isolado e associado a agentes terapêuticos de importância clínica. O enantiômero foi solubilizado em tween 80 e dimetilsulfóxido (DMSO). Posteriormente diluiu-se em água destilada estéril até a concentração de 2048µg/mL. A concentração inibitória mínima (CIM) do produto foi determinada por microdiluição em meio RPMI-1640 obtendo diluições de 4-1024µg/mL. A concentração fungicida mínima (CFM) foi determinada pela técnica de esgotamento em agar Sabouraud dextrose (ASD) a partir de alíquotas de 1mL da CIM, CIM × 2 e CIM × 4. A CIM e a CFM do (R)-(+)-CT para 90% das cepas de C. albicans foram 16 e 32µg/mL respectivamente. No ensaio de suscetibilidade, C. albicans apresentou alta resistência ao fluconazol e ao itraconazol, 12 (92.30%) das cepas. No em tanto, para o cetoconazol e o miconazol a resistência foi de 4 (30.76%) e 3 (23.07%) das cepas respectivamente. No ensaio de combinação do (R)-(+)-CT com cetoconazol e miconazol, a resistência foi completamente revertida. Para o fluconazol e o itraconazol, a resistências foi revertida em 9 (75%) e 7 (58.33%) das cepas respectivamente. O (R)-(+)-CT apresentou atividade fungicida com CFM igual à CIM × 2. Quando em combinação com cetoconazol, fluconazol, itraconazol e miconazol ampliou as zonas de inibição desses antifúngicos, diminuindo a resistência contra C. albicans.

Does scientific evidence for the use of natural products in the treatment of oral candidiasis exist? A systematic review.

In view of the limitations of antifungal agents used in the treatment of oral candidiasis and the wide variety of natural products that have been studied as treatment of this disease, this systematic literature review proposed to evaluate whether scientific evidence attesting to the efficacy of natural products in the treatment of this disease exists. A systematic search in PubMed, MEDLINE, SciELO, Lilacs, and Cochrane Library databases was accomplished using the associations among the keywords Candida albicans, phytotherapy, biological products, denture stomatitis, and oral candidiasis in both English and Portuguese. Four independent observers evaluated the methodological quality of the resulting articles. Three studies were included for detailed analysis and evaluated according to the analysis protocol based on the CONSORT (Consolidated Standards of Reporting Trials) 2010 statement. The tested products were different in all studies. Two studies mentioned random samples, but no study described the sample allocation. No study mentioned sample calculations, a prior pilot study, or examiner calibration, and only one trial reported sample losses. Differences between the tested products and the methodological designs among these studies did not allow the existence of scientific evidence related to the effectiveness of these products for the proposed subjects to be confirmed.

Antifungal activity of plant-based tinctures on Candidas

Objective: To evaluate through determination of minimum inhibitory concentration (MIC) the antifungal activity of Salvia officinalis (sage), Anacardium occidentale (cashew) and Malva sylvestris (mallow) tinctures on Candida albicans (ATCC 40227), C. tropicalis (ATCC 13803) and C. krusei (ATCC 40147). Material and methods: In 96-well microplates, 100 μl of Sabouraud-Dextrose broth doubly concentrated, 100 μl of the tested tinctures and 10 μl of fungal inoculums (1.5 x 106 organisms/ml) were inserted. The products were diluted from initial concentration of 100 mg/ml until 0.78 mg/ml. MIC corresponded to the lowest dilution at which there was no visible fungal growth. Nystatin (100,000 UI/ml) was used as control. Statistical analysis was performed by Kruskal-Wallis and Dunn tests (p < 0.05). Results: S. officinalis tincture did not inhibit the growth of C. albicans and C. tropicalis; MIC was 100 mg/ml for C. krusei. For A. occidentale, MIC was 100 mg/ml for C. albicans and C. krusei, and for C. tropicalis, there was no fungal inhibition. M. sylvestris tincture presented MIC at 25 mg/ml for C. krusei and 100 mg/ml for C. albicans and C. tropicalis. The best antifungal activity was showed by M. sylvestris tincture (p < 0.05). Conclusion: M. sylvestris tincture exhibited antifungal activity against all the tested strains at lower concentrations. S. officinalis tincture inhibited the action of C. krusei and A. occidentale tincture showed activity against C. albicans and C. tropicalis.

Atividade Antifúngica de Extratos Vegetais Brasileiros sobre Cepas de Candida / Antifungal Activity of Brazilian Plant Extracts Against Candida Strains

Avaliar a atividade antifúngica de extratos vegetaisbrasileiros sobre os microrganismos Candida albicans(ATCC289065) – C1, C. tropicalis (ATCC40042) – C2 e C.krusei (ATCC40147) – C3. Material e Métodos: Os extratosvegetais avaliados foram representados pelos óleos essenciaisde Citrus aurantium (laranja), Citrus limmom (limão siciliano),Citrus reticulata (tangerina), Xylopia brasiliensis (pindaíba),Campomanesia xanthocarpa (guabiroba), Ocimum basilicum(manjericão) e Cymbopogon martinii (palmarosa). A atividadeantifúngica dos óleos essenciais foi verificada pela técnica dedifusão em Ágar. Suspensões fúngicas (1,5x106 microrganismos/mL) foram semeadas em placas de Agar Sabouraud-Dextrose,sobre as quais foram distribuídos discos de papel estéreis. Osespécimes foram inundados com 20μL das soluções testadas edo controle, em formulação pura. Os testes foram realizadosem duplicata e a Clorexidina 0,12% serviu de controle. Oshalos de inibição do crescimento fúngico, em milímetros, forammensurados e analisados descritivamente. Resultados: ParaC. aurantium, C. limmom, C. reticulata, X. brasiliensis, C.xanthocarpa, O. basilicum, C. martinii e Clorexidina, a médiados halos de inibição do crescimento foram, respectivamente:14,5; 9,0; 11,5; 11,5; 20,0; 30,0; 40,0; 22,0 (C1); 16,5; 8,0;10,5; 9,0; 36,0; 44,0; 36,0; 26,0 (C2); e 40,0; 8,0; 10,0; 9,5;18,0; 34,0; 36,0; 22,0 (C3). Conclusão: Todos os produtostestados apresentaram atividade antifúngica, sendo as maioresmedidas de halos de inibição apresentadas pelos óleosessenciais de C. xanthocarpa, O. basilicum e C. martinii...

To evaluate the antifungal activity of Brazilian plantextracts against strains of Candida albicans (ATCC289065) –C1, C. tropicalis (ATCC40042) – C2 and C. krusei (ATCC40147)– C3. Methods: The evaluated Brazilian plat extracts wererepresented by essential oils from Citrus aurantium (orange),Citrus limmom (lemon), Citrus reticulata (mandarin), Xylopiabrasiliensis (pindaiba), Campomanesia xanthocarpa(guabiroba), Ocimum basilicum (basil) and Cymbopogon martinii(palmarosa). The antifungal activity of essential oils wasdetermined by agar diffusion technique. Fungal suspensions(1.5 x 106 organisms/mL) were sowed in Sabouraud DextroseAgar, over which were distributed discs of sterile paper. Thespecimens were inundated with 20ìL of tested solutions andcontrol in pure formulation. The tests were performed induplicate and Chlorhexidine Digluconate (0.12%) served ascontrol. The inhibition areas of fungal growth, in millimeters,were measured and analyzed descriptively. Results: For C.aurantium, C. limmom, C. reticulata, X. brasiliensis, C.xanthocarpa, O. basilicum, C. martinii and Chlorhexidine theaverage of the inhibition zones of growth were, respectively:14.5, 9.0, 11.5, 11.5, 20.0, 30.0, 40.0, 22.0 (C1), 16.5, 8.0,10.5, 9.0, 36.0, 44.0, 36.0, 26,0 (C2), and 40.0, 8.0, 10.0, 9.5,18.0, 34.0, 36.0, 22.0 (C3). Conclusions: All products testedpresented antifungal activity, highlighting the essential oilsfrom C. xanthocarpa, O. basilicum and C. martinii, with greatestinhibition zones of fungal growth...

Efeito inibitório de óleos essenciais sobre microrganismos do canal radicular / Inhibitory effect of essential oils against organisms from root canal

Introdução: os óleos essenciais apresentam propriedades biológicas, as quais devem ser estudadas de modo a investigar novas possibilidades de constituição de soluções irrigadoras. Objetivo: avaliar o efeito inibitóriode óleos essenciais extraídos de plantas sobre a atividade de microrganismos envolvidos na infecção do canal radicular. Material e método: foram selecionados os óleos essenciais de Melaleuca alternifolia (melaleuca), Cymbopogon winterianus (citronela), Thymus vulgaris (tomilho), Ocimum basilicum (manjericão), Cymbopogon martinii (palmarosa) e Cinnamomum cassia (canela-da-china). A atividade antimicrobiana sobre Candida albicans (ATCC 289065) e Enterococcus faecalis (ATCC 29212) foi avaliada por meio da triagem da atividade antimicrobiana e da determinação da Concentração Inibitória Mínima (CIM). As soluções de Digluconato de Clorexidina (0,12%) e Hipoclorito de Sódio (1%) serviram de controle. Resultado: os halos de inibição docrescimento para E. faecalis variaram entre 8,00 e 26,00 mm, enquanto que a variação para C. albicans foi entre 26,67 e > 35,00 mm. Os óleos essenciais de T. vulgaris, C. martinii e C. cassia apresentaram CIM na concentração 0,56 mg.mL­1 frente às cepas testadas. Menor atividade foi demonstrada por O. basilicum, que apresentou CIM nas concentrações 72,00 e 1,12 mg.mL­1 contra E. faecalis e C. albicans, respectivamente. Conclusão: os produtos testados apresentaram efeito inibitório satisfatório sobre E. faecalis e C. albicans, destacando-se os óleos essenciais de T. vulgaris, C. martinii e C. cassia.

Introduction: essential oils have biological properties that should be studied in order to investigate new possibilities for formulating irrigating solutions. Objective: the aim was to evaluate the inhibitory effect of essential oils extracted from plants on the activity of organisms involved in root canal infection. Material and method: the essential oils from Melaleuca alternifolia (tea tree), Cymbopogon winterianus (citronella), Thymus vulgaris (thyme), Ocimum basilicum (basil), Cymbopogon martinii (palmarosa) and Cinnamomum cassia (cinnamon) were selected.The antimicrobial activity against Candida albicans (ATCC 289065) and Enterococcus faecalis (ATCC 29212) was evaluated by screening for antimicrobial activity and determination of Minimum Inhibitory Concentration (MIC). The Chlorhexidine Digluconate (0.12%) and 1% Sodium Hypochlorite solutions served as control. Result: the zones of growth inhibition for E. faecalis varied between 8.00 and 26.00 mm, while the zones of inhibition for C. albicans ranged between 26.67 and > 35.00 mm. The essential oils from T. vulgaris, C. martinii and C. cassia showedMIC at concentration of 0.56 mg.mL­1 against the tested strains. Minor activity was demonstrated by the essential oil from O. basilicum, which presented MIC at concentrations of 72.00 and 1.12 mg.mL­1, against E. faecalis and C. albicans, respectively. Conclusion: the tested products presented satisfactory inhibitory effect against E. faecalisand C. albicans, with highlight to the essential oils from T. vulgaris, C. martinii and C. cassia.

Atividade Antifúngica de Antissépticos Bucais sobre candida spp / Antifungal Activity of Mouthwashes on Candida spp

Verificar a atividade antifúngica in vitro dosantissépticos bucais Malvatricim® (P1), Colgate Plax® (P2),Oral B® (P3), Colgate Periogard® (P4) sobre Candidaalbicans (ATCC 40277), Candida albicans (ATCC 289065),Candida krusei (ATCC 40147), Candida tropicalis (ATCC13803) e Candida tropicalis (ATCC 40042). Material eMétodo: Foram confeccionadas suspensões fúngicas(concentração de 106 microrganismos/mL), as quais foramsemeadas em placas com Ágar Sabouraund Dextrose 4%.Realizou-se o teste de difusão em ágar, utilizando-se ametodologia dos poços, nos quais foram inseridos 50μL dosprodutos em sua formulação comercial. Como controlepositivo, utilizou-se a Nistatina 1:100.000 UI (P5). As placasforam incubadas em estufa bacteriológica a 37ºC por 48h.Os testes foram realizados em triplicata e comparados aocontrole positivo. O diâmetro médio dos halos de inibição docrescimento (DMIC) produzidos pelas substâncias foicalculado e representou a ação antimicrobiana. Resultado:Frente a C. albicans (ATCC-289065), C. krusei (ATCC-40147), C. tropicalis (ATCC-40042), e C. tropicalis (ATCC-13803) o P4 teve melhor atuação com DMIC de 15,0mm;15,0mm, 18,0mm e 14,3mm, respectivamente. A cepa de C.albicans (ATCC-40277) foi a única susceptível a P1(DMIC=25,3mm) e resistente a P5. Os colutórios P2, P3 e P4apresentaram atividade antimicrobiana sobre todas as cepastestadas. Conclusão: Concluiu-se que os produtos testados,a exceção do Malvatricim®, apresentaram atividade inibitóriasobre todas as cepas analisadas. O Colgate Periogard®apresentou melhor atividade diante das cepas investigadas,seguido por Colgate Plax®, Oral B® e Malvatricim®...

To verify the in vitro antifungal activity of themouthwashes Malvatricim® (P1), Colgate Plax® (P2), Oral B®(P3) and Colgate Periogard® (P4) on Candida albicans (ATCC40277), Candida albicans (ATCC 289065), Candida krusei(ATCC 40147), Candida tropicalis (ATCC 13803) and Candidatropicalis (ATCC 40042). Material and Methods: Fungalsuspensions were prepared (106 microrganisms / mL) andseeded on Petri dishes containing Sabouraud Dextrose Agar4%. It was followed the agar diffusion method by means ofthe Wells technique. Into each well were inserted 50 μL ofthe products as in their commercial formulation. Nystatin1:100.000 IU (P5) was used as positive control. The plateswere incubated in bacteriological incubator at 37ºC for 48h.Tests were performed in triplicate and compared to positivecontrol. The mean diameter of growth inhibition halos (MDGI)promoted by the substances was calculated and representedthe antimicrobial activity. Results: P4 has showed the mostpotent activity against C. albicans (ATCC-289065), C. krusei(ATCC-40147), C. tropicalis (ATCC-40042), and C. tropicalis(ATCC-13803), with MDGI of 15.0mm; 15.0mm; 18.0mm and14.3mm, respectively. C. albicans strain (ATCC-40277) wasthe only one susceptible to P1 (MDGI=25.3mm) and resistantto P5. The mouthwashes P2, P3 and P4 have presentedantimicrobial activity against all strains assessed. Conclusion:It is concluded that the products under study, exceptingMalvatricim®, have showed inhibitory activity on all strainsassayed. Colgate Periogard® has presented the best activityon the strains investigated, followed by Colgate Plax®, OralB® and Malvatricim®...