Caracterização química e atividade antibacteriana de óleos essenciais de plantas condimentares e medicinais contra Staphylococcus aureus e Escherichia coli

Abstract

INTRODUÇÃOOs óleos essenciais (OEs) são definidos como substâncias complexas voláteis, lipofílicas, geralmente odoríferas e líquidas, oriundas do metabolismo secundário de vegetais. Estes podem ser aplicados em vários segmentos, como antibacterianos, antivirais, antifúngicos, inseticidas e contra o ataque de herbívoros, bem como nos setores de higiene pessoal, perfumaria, cosmética, com um mercado mundial girando em torno de US$ 1,8 bilhão. A participação do Brasil corresponde a apenas 0,1% deste valor sendo 80% referente ao comércio de óleo de laranja (Simões & Spitzer, 2004;Costa, 2008).As propriedades antimicrobianas dos OEs de plantas condimentares e medicinais têm despertado interesse pela perspectiva de constituírem alternativa frente à utilização de aditivos químicos em alimentos. Nos últimos anos tem sido relatado que alguns OEs são capazes de inibir bactérias de origem alimentar e prolongar a vida de prateleira de alimentos processados (Kim et al., 1995; Smith-Palmer et al., 1998 Palavras-chave: antimicrobianos naturais, bactérias, óleos essenciais ABSTRACT: Chemical characterization and antibacterial activity of essential oils from medicinal and condiment plants against Staphylococcus aureus and Escherichia coli.Essential oils are plant secondary metabolites with different biological properties, such as activity against microorganisms, being of major interest to the food industry. The minimal inhibitory concentrations (MIC) of these oils for various bacteria should be determined. The MICvaries according to the oil used by the major compounds and phenotypic and genotypic characteristics of the bacteria. In this research, the essential oils of the plants Satureja montana L., Cymbopogon nardus L. and Citrus limonia Osbeck were chemically characterized and the MIC of the bacteria Staphylococcus aureusATCC 2592 and Escherichia coli ATCC 25922, determined. The MICfor all oils against E. coli was 1.5%, and S. aureus was sensitive to the concentration of 5.0% of S. montanaoil and tothe concentration of 1.5% of the essential oils of the other plants.Chemically, the major components ofthe S. montana, C. nardus and C.limonia Osbeck oils were respectively thymol, citronellal and limonene.

Antimicrobial Susceptibility ofEscherichia coliStrains Isolated fromAlouattaspp. Feces to Essential Oils

“…Our results differed from those found by other researchers, who observed antimicrobial activity in these oils against Gram-positive and Gram-negative bacteria [10, 13, 14, 16]. Studies indicate that how essential oils are obtained, the season, and geographic distribution are factors that can change the composition of these oils and alter their antimicrobial properties [28, 29], thus explaining the different results obtained in a number of studies on plant essential oils.…”

“…These compounds have shown antimicrobial activity against some bacteria, especially E. coli strains [8, 10, 17, 27]. Although the chemical compounds from the EOs used in our study were not analyzed, it could be suggested that o -cymene, γ -terpinene, thymol, and carvacrol were responsible for the antimicrobial effect against E. coli strains isolated from Howler monkeys, since those EOs were already evaluated in a previous study of our group [19].…”

“…Oregano, rosemary, eucalyptus, citronella, lemongrass, and thyme essential oils were purchased from Essential 7 (Roswell, New Mexico, USA), and all of them came in sealed amber glass bottles. EOs selection was based on previous studies from our laboratory and other studies [10–12, 19, 24, 25]. …”

Orange essential oil as antimicrobial additives in poly(vinyl chloride) films

“…Diameters of the inhibition halos shown in Figures 6a and 6b were 21,6 mm and 38,5 mm, respectively. The antimicrobial activity of orange essential oil has also been observed by other authors [48,49] . Table 2 shows the results of tensile tests for mechanical properties, using Young's modulus, percentage elongation at break and tensile strength of PVC films, PVC/2%OEO, PVC/10%OEO and PVC/30%OEO.…”

Chemical composition and antibacterial activity of essential oils from Citrus aurantifolia leaves and fruit peel against oral pathogenic bacteria

“…Promising anticariogenic activity shown by essential oils from C. aurantifolia may be justified by their major constituents, i.e., limonene, linalool, citronellal and citronellol, whose antibacterial potential has already been reported by the literature (Valeriano et al 2012, Millezi et al 2014. In addition, Bezerra et al (2013) stated that bacterial strains of S. mutans, S. oralis and S. salivarius were susceptible to the activity of phytoconstituents linalool, citronellol and limonene.…”