Mangaba (hancornia speciosa): exploring potent antifungal and antioxidant properties in lyophilised fruit pulp extract through in vitro analysis.

Mangaba is a fruit native to Brazil, rich in bioactive compounds. To evaluate physicochemical composition, bioactive compounds, antioxidant and antifungal activity of mangaba fruit pulp. Moisture, ash, protein, lipid, energy values and phenolic compounds were determined. Antioxidant activity was determined by capture of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Evaluation of antifungal activity was performed by Minimum Inhibitory Concentration, according to protocols M07-A9 and M27-S3, and minimum fungicidal concentration. Freeze-dried mangaba pulp presented high levels of carbohydrates, low levels of lipids, and high energy density. Phenolic analysis demonstrated that chlorogenic acid was found in the highest concentration, followed by p-coumaric acid and ferulic acid. Mangaba extract showed antioxidant activity like BHT. Mangaba extract inhibited the growth of Candida albicans (ATCC 90028), Cryptococcus gattii (AFLP4), Candida guilliermondii (ATCC 6260) and Candida albicans (MYA 2876). Freeze-dried mangaba inhibited fungal activity associated with antioxidant effect due to presence of phenolic compounds.

Evaluation of efficacy of new chalcone-based endodontic irrigant against dual biofilm Enterococcus faecalis and Candida albicans: a study in vitro.

The aim of this research was to develop a chalcone-based endodontic irrigant for cleaning and disinfecting the root canal. Minimal inhibitory concentration (MIC) experiments in C. albicans and E. faecalis strains with different aminochalcones (AM) were carried out, and the compound that presented the best activity against both pathogens was chosen. The formulation of an endodontic irrigant was elaborated, tested in mono and dual specie biofilms. Disks were sterilized and then incubated with E. faecalis, C. albicans and E. faecalis and C. albicans mixed for 72 h for biofilm maturation. After contamination, samples were divided in 4 experimental groups and 2 positive control group as follows: Group1: Irrigant; Group2: Irrigant + AM-38; Group3: Chlorhexidine 2% (positive control) and, Group 4: 1.0% sodium hypochlorite (positive control). The samples were analyzed by CFU/ml count. The sample was taken to sonicador to remove the cells and then plated. The toxicity was determined in vitro with human gingival fibroblast cells (HGF) and in vivo using the Galleria mellonella model. Formulation showed antimicrobial activity, with MIC on C. albicans 15.6 and E. faecalis 7.8 µg/ml. Treatment with formulation in concentration 156 µg/ml significantly reduced mono or dual species biofilm formation and viability (p < 0.05). The results were significant against C. albicans and E. faecalis and did not show toxicity in cells and G. mellonella. In general, the formulation showed effective antibiofilm activity, significantly reducing microorganisms, opening paths in search of new endodontic irrigants.

Prevention of hospital pathogen biofilm formation by antimicrobial peptide KWI18.

This study investigated the antimicrobial and antibiofilm activity of KWI18, a new synthetic peptide. KWI18 was tested against planktonic cells and Pseudomonas aeruginosa and Candida parapsilosis biofilms. Time-kill and synergism assays were performed. Sorbitol, ergosterol, lipid peroxidation, and protein oxidation assays were used to gain insight into the mechanism of action of the peptide. Toxicity was evaluated against erythrocytes and Galleria mellonella. KWI18 showed antimicrobial activity, with minimum inhibitory concentration (MIC) values ranging from 0.5 to 10 µM. KWI18 at 10 × MIC reduced P. aeruginosa and C. parapsilosis biofilm formation and cell viability. Time-kill assays revealed that KWI18 inhibited the growth of P. aeruginosa in 4 h and that of C. parapsilosis in 6 h. The mechanism of action was related to ergosterol as well as induction of oxidative damage in cells and biofilms. Furthermore, KWI18 demonstrated low toxicity to erythrocytes and G. mellonella. KWI18 proved to be an effective antibiofilm agent, opening opportunities for the development of new antimicrobials.

Atividade antifúngica do a-terpinen sobre Candida albicans / Antifungal activity of a-terpinen on Candida albicans

Objetivo: avaliar a atividade antifúngica do a- terpinen sobre culturas planctonicas e biofilme de Candida albicans. Material e Métodos: Primeiramente, foi determinada a Concentração Inibitória Mínima (CIM) e a Concentração Fungicida Mínima (CFM) do a-terpinen sobre microrganismos planctônicos. A Nistatina foi utilizada como controle positivo. Biofilme de Candida albicans foi desenvolvido e, após o tratamento com diferentes concentrações de α-terpinen, foi quantificado em UFC/mL, além da atividade metabólica das células ser avaliada por XTT. Resultados: a menor concentração capaz de inibir o crescimento (CIM) foi 0,2 % para o a-terpinen e 4 µg/mL para a Nistatina. Na CIM, os resultados mostraram que a partir da concentração 0,05 % de α-terpinen e 2 µg/mL de Nistatina houve diminuição de C.albicans quando comparado ao controle. A CFM foi para a-terpinen 0,2 % e Nistatina 8 µg/mL. Na quantificação as concentrações eficazes foram de α-terpinen (0,1%) e Nistatina (128µg/mL), e no teste do XTT, observou-se que α -terpinen (0,1%) e Nistatina (256µg/mL) diminuem a viabilidade quando comparado com o controle. Conclusão: Assim, pode-se afirmar que α -terpineol pode ser uma alternativa para tratamento de infecções fúngicas.

Objective: to evaluate the antifungal activity of a-terpinen on planktonic cultures and biofilm of Candida albicans. Material and Methods: first, Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (CFM) of a-terpinen were determined. Nystatin was used as a positive control. Biofilm of Candida albicans was developed and, after treatment with different concentrations of a-terpinen, was quantified in CFU/mL, in addition to metabolic activity of the cells being evaluated by XTT. Results: the lowest concentration able to inhibit the growth (MIC) was 0.2% for a-terpinen and 4 µg / mL for Nystatin. Results showed that from the concentration 0.05% of α -terpinen and 2 µg / mL of Nystatin, there was a decrease of Candida albicans when compared to the control, in planktonic culture. CFM was 0.2% for α -terpinen and 8 µg / mL for Nystatin. Regarding the quantification, effective concentrations were α-terpinen (0.1%) and Nystatin (128 µg/mL), and in the XTT test, α-terpinen (0.1%) and Nystatin (256 µg/mL) decreased metabolic activity when compared to control. Conclusion: Thus, it can be stated that a-terpineol may be an alternative for the treatment of fungal infections.