Conservação de formulação tópica utilizando micocinas produzidas por Wickerhamomyces anomalus

Abstract

After reports of adverse reactions and endocrine disruption caused by some preservatives such as parabens, widely used in topical formulations and medicines, the cosmetic and pharmaceutical industry faces a considerable lack of additives with less toxicity, triggering interest in the search for the development of new preservative systems safe and effective. Natural substances with a broad spectrum of antimicrobial activity and low toxicity are interesting alternatives for the research of new preservatives. Mycocins are natural substances produced by killer yeasts. They have the potential to inhibit bacteria, filamentous fungi and yeast with a broad spectrum of action, low toxicity and low probability of inducing microbial resistance. Wickerhamomyces anomalus is a mycocin-producing yeast with vast potential for industrial application. This study aimed to verify the preservative activity of mycocins produced by W. anomalus when incorporated into dermatological gels, stability of mycocins in the formulation and membrane irritation potential. β-glucanases determination assays , β-glucanase assay, microdilution, Challenge Test to evaluate the effectiveness of preservative action against standard microorganisms: Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Staphylococcus aureus (ATCC 6538), Candida albicans (ATCC 10231) and Aspergillus niger (ATCC 16404), stability tests: preliminary, accelerated, normal and shelf life and membrane irritability assay in organotypic model. The WA92 supernatant showed β- glucanase activity of 3.80 U/mg. In the microdilution assay, all standard microorganisms tested were sensitive to WA92 mycocins at their maximum concentration of 3.80 U/mg. E. coli and A. niger were totally inhibited at the concentration of 1.90 U/mg, P. aeruginosa 0.95 U/mg, S. aureus 0.48 U/mg and C. albicans 0.24 U/mg. In the Challenge Test, the preservative efficacy criteria were met for bacteria, filamentous fungus and yeast. The formulations incorporated with mycocins were stable under the different storage conditions to which they were submitted. Thus, the results described in this work indicate that the mycocins produced by W. anomalus WA92 are a promising and safe antimicrobial substance for the development of news preservative systems in formulations.