Optimum synthesis of CuO nanoparticles with the highest antifungal activity against oral pathogen Candida albicans

This research was aimed to optimize the synthesis of copper oxide (CuO) nanoparticles with the highest antifungalproperties against Candida albicans as an oral fungal pathogen. To this end, nine experiments involving differentsynthesis conditions were designed using the Taguchi method and the copper oxide nanoparticles synthesized bycoprecipitation method. The antifungal activity of synthesized nanoparticles against C. albicans was evaluatedusing the colony forming unit and disk diffusion methods. According to the results, the synthesized copper oxidenanoparticles under the five experimental conditions (CuCl2 0.1 M, NaOH 0.1 M, and a 75 minutes stirring time)showed the highest antifungal activity against C. albicans (71.72%). The optimization results demonstrated thatall three studied factors were effective in improving the antifungal activity of copper oxide nanoparticles and theantifungal activity in the proposed conditions can be improved by 77.85%. The synthesis of nanoparticles in optimalconditions confirmed the improved antifungal activity of the nanoparticles. The results of this study proved that CuOnanoparticles have a potential ability as an antifungal agent against oral fungal pathogens of C. albicans.

Efecto antimicrobiano del aceite esencial de Citrus reticulata sobre Fusobacterium nucleatum asociada a enfermedad periodontal / Antimicrobial effect of essential oil of Citrus reticulata on Fusobacterium nucleatum associated with periodontal disease

Resumen La clorhexidina como tratamiento de la enfermedad periodontal ha logrado efectos bactericidas sobre periodontopatógenos y biopelícula oral. Su uso genera efectos adversos, por lo tanto se presentan alternativas naturales con efecto antimicrobiano similar. Los aceites esenciales han demostrado efectividad en el control de la placa dental, sin los efectos adversos de la clorhexidina. El objetivo de este estudio fue determinar el efecto bacteriostático y bactericida del aceite esencial de mandarina contra Fusobacterium nucleatum. Se realizó extracción por expresión del aceite esencial de cáscaras de mandarina (variedades Arrayana y Oneco). Se evaluaron concentraciones al 20%, 40%, 60%, 80% y 100% del aceite esencial diluido en Tween al 0,02%. El efecto bacteriostático y bactericida se determinó por pruebas de sensibilidad antimicrobiana por difusión en disco. Como control positivo se utilizó Clorhexidina 0,2% y agua como control negativo. Se midió halo de inhibición (mm) y se determinó ausencia o presencia de crecimiento bacteriano a partir de unidades formadoras de colonias. Para comparación de proporciones de la actividad bacteriostática y bactericida, se realizó prueba de Fisher y T student (IC 95% p = 0,05). El halo de inhibición a una concentración del 100% mostró comportamiento similar a clorhexidina (p<0,05). Concentraciones al 100% y 80% fueron bactericidas, al 60%, 40% y 20% presentaron comportamiento bacteriostático. No se encontraron diferencias significativas en las proporciones de inhibición entre las dos variedades de mandarina (p>0,05). El uso de aceites esenciales de mandarina podría ser una alternativa complementaria al tratamiento de la enfermedad periodontal.

Abstract Chlorhexidine as a treatment of periodontal disease has achieved bactericidal effects over periodontopathogens and oral biofilm. Its use generates adverse effects; therefore natural alternatives are presented with a similar antimicrobial effect. Essential oils have proved effective in controlling dental plaque without the adverse effects of chlorhexidine. The aim of this study was to determine the bacteriostatic and bactericidal effect of essential oil of tangerine against Fusobacterium nucleatum. The extraction of the essential oil was performed by expression of tangerine peels (Arrayana and Oneco varieties). Concentrations at 20%, 40%, 60%, 80% and 100% of the essential oil diluted in 0,02% Tween were evaluated. The bacteriostatic and bactericidal effect was determined by antimicrobial susceptibility testing by disk diffusion. As a positive control 0,2% chlorhexidine and water as negative control were used. Inhibition zone (mm) was measured and presence or absence of bacterial growth was determined from colony forming units. To compare proportions of bacteriostatic and bactericidal activity, Fisher and T student test (95% CI p = 0,05) were performed. The 100% concentration zone of inhibition showed a similar behavior as chlorhexidine (p <0,05). 100% and 80% concentrations were bactericides, 60%, 40% and 20% showed bacteriostatic behavior. No significant differences between the proportions of inhibition of the two varieties of tangerine (p> 0,05). The use of essential oils of tangerine could be a complementary alternative to treatment of periodontal disease.

Two new limonoids isolated from the fuits of Melia toosendan / 中国天然药物

In the present study, two new limonoids, 1α, 7α-dihydroxyl-3α-acetoxyl-12α-ethoxylnimbolinin (1) and 1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12β-ethoxylnimbolinin (2), together with other four known limonoids (3-6), were isolated from the fruits of Melia toosendan. Their structures were elucidated by means of extensive spectroscopic analyses (NMR and ESI-MS) and comparisons with the data reported in the literature. The isolated compounds were evaluated for their antibacterial activities. Compound 4 exhibited significant antibacterial activity against an oral pathogen, Porphyromonas gingivalis ATCC 33277, with an MIC value of 15.2 μg·mL(-1). Compound 2 was also active against P. gingivalis ATCC 33277, with an MIC value of 31.25 μg·mL(-1). In conlcusion, our resutls indicate that these compounds may provide a basis for future development of novel antibiotics.

The antibacterial activity of various saturated and unsaturated fatty acids against several oral pathogens.

The antibacterial activity of various saturated fatty acids (SFA) and unsaturated fatty acids (USFA) against different oral pathogens which are implicated in the cause of dental caries, stomatitis, gingivitis, and periodontitis was examined. The saturated fatty acids Pa, StA and ArA, and the unsaturated w-7 fatty acids PLA and w-9 fatty acids OA showed either none to low antimicrobial activity against all of the 12 oral pathogenic strains used in this study. In contrast, the w-3 PUFAs, ALA, SDA, EPA and DHA, and the w-6 PUFAs, LA, GLA, and AA showed considerable antimicrobial activity against 8, 7, 6 and 5 strains, and 6, 10 and 5 strains, respectively. In particular, the w-3 and w-6 PUFAs showed strong antimicrobial activity against Porphyromonas gingivalis KCTC 381, the cause of periodontitis, and against Aggregatibacter segnis KCTC 5968, Fusobacterium nucleatum subsp. Polymorphum KCTC 5172 and Prevotella intermedia KCTC 25611, all organisms implicated in the cause of gingivitis. To date, no bacterial resistance to free fatty acids has been encountered and no resistance phenotype has emerged. Therefore, these results suggest that PUFAs may be useful in the development of therapeutic agents for oral diseases, and in particular, in the development of agents that have minimal side effects and against which there is no bacterial resistance.