Antifungal activity of toothpastes against oral Candida isolates

Candida albicans and NCAC species: acidogenic and fluoride-resistant oral inhabitants

Objective

Although Candida species are thought to contribute to dental caries, their acid production under anaerobic conditions and susceptibility to fluoride have not been thoroughly studied. We therefore investigated the growth, acid production, and effect of fluoride on Candida species.

Methods

Aerobic growth, acid production from glucose and its end-products under aerobic and anaerobic conditions, and enolase activity were measured in C. albicans and non-Candida-albicans-Candida (NCAC) species (C. tropicalis, C. parapsilosis, C. maltosa, and C. glabrata), and the effect of fluoride on these abilities was evaluated.

Results

All Candida species produced acids under aerobic and anaerobic conditions, and acetate and TCA cycle metabolites were detected. However, these organic acids only accounted for 1.9-57.6% of the acids produced. Up to 80 mM fluoride hardly inhibited growth and did not inhibit acid production except for C. glabrata, despite the low 50% inhibitory fluoride concentration of 0.19-0.34 mM for enolase.

Conclusion

Candida species produced acids under aerobic and anaerobic conditions, indicating their significant cariogenicity. Their growth and acid production were highly fluoride-resistant, whereas their enolase was fluoride-sensitive, suggesting mechanisms for maintaining low intracellular fluoride. The mechanisms underlying the fluoride resistance remain underexplored. Approaches other than fluoride may be needed to control Candida-associated caries.

Antifungal Activity of Ocimum tenuiflorum and Ocimum gratissimum Herbal Formulation-Based Oral Rinse Against Candida albicans

Background Candida albicans is a common fungal pathogen responsible for oral infections, posing significant health challenges. Traditional antifungal treatments often come with side effects and resistance issues, highlighting the need for effective natural alternatives. O. tenuiflorum and Ocimum gratissimum are known for their medicinal properties, including antifungal activity. Objective This study aimed to evaluate the antifungal effectiveness of an O. tenuiflorum and O. gratissimum herbal formulation-based oral rinse against C. albicans. Methods Antifungal activity was measured using agar well diffusion, time-kill curve assays, and analyses of cytoplasmic and protein leakage. The herbal rinse was tested at concentrations of 25 µg/mL, 50 µg/mL, and 100 µg/mL, and compared to a commercial oral rinse. Results The herbal rinse demonstrated strong antifungal effects that increased with concentration. At 100 µg/mL, it produced a 13 mm zone of inhibition, outperforming the commercial rinse's 11 mm. The time-kill assay revealed that the 100 µg/mL concentration reduced fungal counts to 103 CFU/mL within 5 hours, on par with the commercial rinse. Cytoplasmic leakage analysis showed an optical density of 0.42 at 100 µg/mL, close to the commercial rinse's 0.45. Protein leakage analysis indicated an optical density of 0.52 at 100 µg/mL, slightly higher than the commercial rinse's 0.51. Conclusion The O. tenuiflorum and O. gratissimum herbal formulation-based oral rinse exhibit potent antifungal activity against C. albicans, rivaling and even surpassing commercial rinses at higher concentrations. This study underscores the potential of this natural oral rinse as a powerful alternative for managing oral fungal infections, meriting further research and clinical trials to confirm its long-term safety and efficacy.

Role of clove oil in solvent exchange-induced doxycycline hyclate-loaded Eudragit RS in situ forming gel

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Role of clove oil (CO) in doxycycline hyclate (DH)-loaded Eudragit RS (ERS) in situ forming gel (ISG) was investigated.

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CO could solubilize ERS and increase the viscosity of ISG and also minimize DH burst release with sustainable DH release.

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ISGs comprising CO could expel through the 27-gauge needle and transform into matrix depot in simulated crevicular fluid.

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Antimicrobial activities against all test bacterias were increased when increasing CO and N-methyl pyrrolidone (NMP) ratio.

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DH-loaded ERS ISG comprising CO could be used as a local drug delivery system for periodontitis treatment.

Solvent exchange induced in situ forming gel (ISG) is the promising drug delivery system for periodontitis treatment owing to the prospect of maintaining an effective high drug level in the gingival crevicular fluid. In the present study, the influence of clove oil (CO) on the characteristics of doxycycline hyclate (DH)-loaded ISG comprising Eudragit RS (ERS) was investigated including viscosity/rheology, syringeability, in vitro gel formation/drug release, matrix formation/solvent diffusion and antimicrobial activities. CO could dissolve ERS and increase the viscosity of ISG and its hydrophobicity could also retard the diffusion of solvent and hinder the drug diffusion; thus, the minimization of burst effect and sustained drug release were achieved effectively. All the prepared ISGs comprising CO could expel through the 27-gauge needle for administration by injection and transform into matrix depot after exposure to the simulated gingival crevicular fluid. The antimicrobial activities against Staphylococcus aureus, Escherichia coli, Streptococcus mutans and Porphyromonas gingivalis were increased when the ratio of CO and N-methyl pyrrolidone (NMP) was decreased from 1:1 to 1:10 owing to higher diffusion of DH except that for C. albicans was increased as CO amount was higher. Therefore, CO could minimize the burst while prolonging the drug release of DH-loaded ERS ISG for use as a local drug delivery system for periodontitis treatment.

Análise da contaminação microbiológica de diferentes dentifrícios

Resumo Introdução A avaliação microbiológica em produtos de higiene pessoal constitui uma etapa importante no que se refere à segurança do usuário e à qualidade do produto, visto que a carga microbiana elevada pode acarretar problemas de saúde, especialmente em pessoas imunocomprometidas. Objetivo Verificar o cumprimento das exigências acerca da qualidade microbiológica de cremes e géis dentais adquiridos comercialmente. Material e método Realizou-se a contagem de bactérias e fungos viáveis totais e pesquisa dos patógenos E. coli, Salmonella sp., S. aureus e P. aeruginosa em 21 amostras. Resultado Das amostras analisadas, 52,0% apresentaram crescimento microbiano e 28,6% e 0,21% apresentaram contaminação fúngica e bacteriana, respectivamente, acima dos limites descritos na Farmacopeia Brasileira para preparações de uso tópico (máximo permitido 2 × 102 UFC/g de bactérias e 2 × 101 UFC/g de fungos). Nenhuma amostra apresentou os patógenos pesquisados E. coli, Salmonella sp., S. aureus e P. aeruginosa. Conclusão Estes resultados indicam que muitos produtos disponíveis no mercado apresentam qualidade inadequada, demonstrando falhas no controle de qualidade. Para prevenir esta situação, faz-se necessária fiscalização rigorosa e adoção de medidas regulamentadoras e educacionais aliadas ao seguimento das Boas Práticas de Fabricação pelas indústrias fabricantes.

Assessment of antifungal activity of herbal and conventional toothpastes against clinical isolates of Candida albicans

OBJECTIVE

To detect the anticandidal activity of nine toothpastes containing sodium fluoride, sodium monofluorophosphate and herbal extracts as an active ingredients against 45 oral and non oral Candida albicans (C. albicans) isolates.

METHODS

The antifungal activity of these toothpaste formulations was determined using a standard agar well diffusion method. Statistical analysis was performed using a statistical package, SPSS windows version 15, by applying mean values using one-way ANOVA with post-hoc least square differences (LSD) method. A P value of less than 0.05 was considered significant.

RESULTS

All toothpastes studied in our experiments were effective in inhibiting the growth of all C. albicans isolates. The highest anticandidal activity was obtained from toothpaste that containing both herbal extracts and sodium fluoride as active ingredients, while the lowest activity was obtained from toothpaste containing sodium monofluorophosphate as an active ingredient. Antifungal activity of Parodontax toothpaste showed a significant difference (P< 0.001) against C. albicans isolates compared to toothpastes containing sodium fluoride or herbal products.

CONCLUSIONS

In the present study, it has been demonstrated that toothpaste containing both herbal extracts and sodium fluoride as active ingredients are more effective in control of C. albicans, while toothpaste that containing monofluorophosphate as an active ingredient is less effective against C. albicans. Some herbal toothpaste formulations studied in our experiments, appear to be equally effective as the fluoride dental formulations and it can be used as an alternative to conventional formulations for individuals who have an interest in naturally-based products. Our results may provide invaluable information for dental professionals.

Assessment of dentifrices against Candida biofilm

The invasion of opportunistic pleiomorphic Candida albicans into oral cavity environment leads to development and progression of its resistance to both naturally occurring antifungal peptides in human saliva as well as commercially available antifungal therapies. As a result of this, the usage and popularity of natural medicine and dentifrices had increased significantly in the last decade. In the present investigation, we have assessed the action of locally available dentifrices against C. albicans biofilm. Disk diffusion test showed maximum zone of inhibition (20 mm) by herbal dentifrice (D-5) as compared to other dentifrices when incubated at 37 °C and 48 h. Assessment of dentifrice D-5 for its effectiveness against C. albicans was further shown in MIC(90) (3.12 mg mL(-1)) and SMIC(90) (6.2 mg mL(-1)) values for planktonic and sessile cells (biofilm forming), respectively. Our data depicted 80% reduction in the cell surface hydrophobicity when 6.2 mg mL(-1) of herbal dentifrice D-5 was used against 48-h grown Candida biofilm at 37 °C. Visualization of herbal dentifrice D-5-treated C. albicans biofilm under SEM revealed drastic reduction in the dense network of yeast, hyphae, and pseudohyphae enclosed in its ECM as compared to its control biofilm. The data were further supported by CLSM analysis which depicted C. albicans architecture disruption by herbal dentifrices. From the above data, it is inferred that these studies would provide researchers and medical practitioners with better insight into the antifungal effect of natural herbal dentifrices.

A comparison of the antifungal activity of herbal toothpastes against other brands of toothpastes on clinical isolates of Candida albicans and Candida dubliniensis

OBJECTIVES

To evaluate the anti-Candida activity on Candida albicans and Candida dubliniensis species of 2 herbal and 7 other brands of toothpastes commonly used in Kuwait.

MATERIALS AND METHODS

Antifungal activity was determined by agar diffusion test on 65 isolates of C. albicans and 21 isolates of C. dubliniensis for each toothpaste. A uniform quantity of toothpaste was filled into wells punched into Sabouraud dextrose agar medium plates inoculated with the test isolates, incubated at 37°C; inhibition zone diameters were read after 24 h.

RESULTS

The mean inhibition zone diameters ranged between 12 and 23 mm for C. albicans and between 12 and 27 mm for C. dubliniensis. A herbal toothpaste brand manufactured in the Middle Eastern region (United Arab Emirates) consisting of many herbal ingredients compared to other brands was found to be the most active (p < 0.001) against both Candida species tested, which also demonstrated higher inhibitory activity against C. dubliniensis isolates compared to C. albicans.

CONCLUSIONS

The herbal toothpaste brand presented significant anticandidal activity over conventional toothpastes and may be useful in reducing the pathogenic potential of Candida species.