Propriedades físico-químicas e atividades biológicas de óleos essenciais de Mentha pulegium L., Corymbia citriodora e Cymbopogon citratus, incorporados em géis antissépticos

Abstract

The essential oils constitute an important phytochemical group composed of secondary metabolites used in the industries with emphasis in the alimentary, cosmetic and pharmaceutical areas. The aromatic attributes and the biological activities of these substances put them today in a prominent position. The objectives of this work were to chemical characterize the essential oils of Mentha pulegium L., Corymbia citriodora e Cymbopogon citratus, develop topical antiseptic formulations in the form of gel with the addition of the essential oils incorporated into the hydroxyethylcellulose and carboxypolymethylene bases, as well as the evaluation of physicochemical, antibacterial, phospholipase activities and effects on human erythrocytes. The essential oils were obtained from the fresh leaves of Mentha pulegium L., Corymbia citriodora e Cymbopogon citratus and extracted by hydrodistillation using the modified Clevenger apparatus. They were characterized and quantified by CG / MS and CG / DIC, respectively. The physico-chemical evaluations were performed by evaluating the pH, release tests, spreadability, centrifugal stability and density; in addition to studying the antibacterial activities (Escherichia coli and Staphylococcus aureus), skin irritation, sun protection factor, phospholipase, effect on erythrocytes and evaluation of microbiological activity (contamination of gels). The essential oil of M. pulegium presented as main constituents pulegone, menthol and menthone and the essential oils of C. citridora and C. citratus presented geranial and general. The results showed that carboxypolymethylene gels incorporated with essential oils had lower variations in physico-chemical behavior. Comparing the effect of the incorporation of the essential oils to the gels, it was possible to observe that the gels without the addition of oils maintained for longer the characteristic referring to the pH. In the release test, dialysis showed that the M. pulegium hydroxyethylcellulose gel presented more expressive results, followed by gel C. citriodora-carboxypolymethylene and C. citratus-carboxypolymethylene. The viscosity of the gels up to 30 days showed a decrease reducing the spreadability, however from 60 days all became more viscous. The pH presented reduction for all formulations tested, also showing loss of stability of the gels. Before the biological tests it was possible to observe that, compared to the commercial antiseptic,gel alcohol, the formulations presented irritation to a lesser degree and by the hemolysis and phospholipase tests, no toxicity of the products was verified. The gels did not present a sun protection factor and the antibacterial activity against S. aureus and E. coli was significant and superior than that of alcohol in gel, besides these parameters, the gels did not present contamination. The essential oils gels of M. pulegium, C. citriodora and C. citratus presented characteristics of interest for the production of new products with antiseptic potential.