Atividade antibacteriana e caracterização físico-química de óleos essenciais extraídos das plantas medicinais comumente utilizadas pela população de São Luís do Maranhão
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Data
2017-04-28
Autores
Pereira, Alvaro Itauna Schalcher [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os óleos essenciais obtidos de plantas medicinais vêm sendo ressaltados ao longo das décadas e sua eficácia tem sido evidenciada por pesquisadores de todo mundo, devido ao seu efeito antibacteriano. Objetivou-se avaliar a atividade antibacteriana de óleos essenciais extraídos por hidrodestilação e determinar a composição química por cromatografia gasosa acoplada à espectrometria de massas (CG/EM) de cinco plantas medicinais dentre elas alecrim (Rosmarinus officinalis L.), capim-limão (Cymbopogon citratus (D. C.) Stapf), cravo-da-índia (Caryophyllus aromaticus L.), eucalipto (Eucalyptus citriodora H.) e manjericão (Ocimum basilicum L.), selecionadas em mercados e/ou feiras livres de São Luís – MA. Para tanto, os testes microbiológicos foram utilizados seis cepas bacterianas da American (ATCC): Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 10876) e Enterococcus faecalis (ATCC 29212) Gram-positivas além de Escherichia coli (ATCC 25922), Salmonella enterica sorotipo Choleraesuis (ATCC 12011) e Pseudomonas aeruginosa (ATCC 9027) Gram-negativas e comparados com antimicrobiano padrão. As Concentrações Mínimas Inibidoras (MIC) utilizadas foram 25, 50, 75 e 100µɡ/mL. Os resultados da atividade antibacteriana in vitro com os halos de inibição das espécies bacterianas selecionadas, foram analisadas sobre teste de ANOVA, utilizando-se o Delineamento em Blocos ao Acaso, contendo cinco tratamentos, em dois blocos sendo possível constatar a não existência de diferença estatística em variáveis (p≤0,05). Para o óleo essencial do capim-limão, em especial para Staphylococcus aureus e Bacillus cereus com concentração de 75µɡ/mL. O óleo essencial do cravo-da-índia, atingiu um resultado frente à bactéria Staphylococcus aureus com uma concentração de 25µɡ/mL e as demais bactérias Bacillus cereus, Escherichia coli e Salmonella enterica sorotipo Choleraesuis com 50µɡ/mL, sendo Pseudomonas aeruginosa na concentração de 100µɡ/mL. O óleo essencial de Eucalipto conseguiu obter um resultado parcialmente ativo para as bactérias gram-negativas Escherichia coli e Salmonella enterica sorotipo Choleraesuis com concentração a partir de 50µɡ/mL e ativo para uma concentração de 75µɡ/mL para a bactéria gram-positiva Staphylococcus aureus. Por fim, o óleo essencial do manjericão na concentração de 25µɡ/mL sendo ativo perante a bactéria Staphylococcus aureus, aumentou-se a concentração para 50mg/mL na Gram-positiva Bacillus cereus e nas duas Gram-negativas Escherichia coli e Salmonella enterica sorotipo Choleraesuis, ambas sofreram a ação bactericida do óleo essencial. A bactéria Enterococcus faecalis apesar de ter sido classificada pelo halo de inibição ativa precisou de concentração mínima do estudo. Os óleos essenciais foram analisados por cromatografia de gases e espectrometria de massas – CG/EM e determinados os parâmetros físico-químicos: densidade, índice de refração, solubilidade em álcool (70%), odor, cor, aparência. Posteriormente, os picos cromatográficos (fingerprints) dos componentes minoritários e majoritários presentes nas diferentes frações dos cincos óleos essenciais foram identificados e quantificados. Para tanto, os compostos identificados pela análise química de CG/EM constataram a presença de monoterpenos e sesquiterpenos hidrocarbonados (não oxigenados) e oxigenados, além de três fenilopropanoides com diversidade de estruturas químicas de baixo peso molecular. Assim sendo, estudos futuros, visando à aplicabilidade destes óleos como aditivos naturais, devem ser realizados na tentativa de aumentar a vida de prateleira de alimentos, bem como melhorar as características físico-químicas e alcançar a segurança alimentar desejada.
Essential oils obtained from medicinal plants have been highlighted over the decades and their efficacy has been evidenced by researchers around the world due to their antibacterial effect. The objective of this study was to evaluate the antibacterial activity of essential oils extracted by hydrodistillation and to determine the chemical composition by gas chromatography coupled to mass spectrometry (CG/MS) of five medicinal plants such as rosemary (Rosmarinus officinalis L.), lemon grass (Cymbopogon citratus (DC) Stapf), clove (Caryophyllus aromaticus L.), eucalyptus (Eucalyptus citriodora H.) and basil (Ocimum basilicum L.), Selected in markets and/or free fairs of São Luís - MA. For this purpose, six bacterial strains of Gram-positive American Type Culture Colletion (ATCC): Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 10876) and Enterococcus faecalis (ATCC 29212) were used in addition to Escherichia coli (ATCC 25922), Salmonella enterica serotype Choleraesuis (ATCC 12011) and Pseudomonas aeruginosa (ATCC 9027) Gram-negative and compared with standard antimicrobial. The Minimum Inhibitory Concentrations (MIC) used were 25, 50, 75 and 100μɡ/mL. The results of the in vitro antibacterial activity with the inhibition halos of the selected bacterial species were analyzed on the ANOVA test, using the randomized block design, containing five treatments, in two blocks and it was possible to verify the existence of statistical difference In variables (p≤0,05). For lemongrass essential oil, especially for Staphylococcus aureus and Bacillus cereus with a concentration of 75μɡ/mL. The essential oil of the clove reached a result against Staphylococcus aureus with a concentration of 25μɡ/mL and the other bacteria Bacillus cereus, Escherichia coli and Salmonella enterica serotype Choleraesuis with 50μɡ/mL, being Pseudomonas aeruginosa at the concentration of 100μɡ/mL. Finally, the essential oil of basil at a concentration of 25μɡ/mL being active against the bacterium Staphylococcus aureus, the concentration was increased to 50mg / mL in Gram-positive Bacillus cereus and in the two Gram-negative Escherichia coli and Salmonella enterica serotype Choleraesuis, Both underwent the bactericidal action of the essential oil. The bacterium Enterococcus faecalis, despite being classified by the active inhibition halo, required a minimum concentration of the study. The essential oils were analyzed by gas chromatography and GC/MS mass spectrometry and the physicochemical parameters were determined: density, refractive index, alcohol solubility (70%), odor, color, appearance. Subsequently, the fingerprints of the minority and major components present in the different fractions of the five essential oils were identified and quantified. For this, the compounds identified by the GC/MS chemical analysis showed the presence of monoterpenes and hydrocarbon (non-oxygenated) and oxygenated sesquiterpenes, in addition to three phenylpropanoids with a diversity of low molecular weight chemical structures. Therefore, future studies aiming at the applicability of these oils as natural additives should be carried out in an attempt to increase the shelf life of foods, as well as to improve the physico-chemical characteristics and achieve the desired food safety.
Essential oils obtained from medicinal plants have been highlighted over the decades and their efficacy has been evidenced by researchers around the world due to their antibacterial effect. The objective of this study was to evaluate the antibacterial activity of essential oils extracted by hydrodistillation and to determine the chemical composition by gas chromatography coupled to mass spectrometry (CG/MS) of five medicinal plants such as rosemary (Rosmarinus officinalis L.), lemon grass (Cymbopogon citratus (DC) Stapf), clove (Caryophyllus aromaticus L.), eucalyptus (Eucalyptus citriodora H.) and basil (Ocimum basilicum L.), Selected in markets and/or free fairs of São Luís - MA. For this purpose, six bacterial strains of Gram-positive American Type Culture Colletion (ATCC): Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 10876) and Enterococcus faecalis (ATCC 29212) were used in addition to Escherichia coli (ATCC 25922), Salmonella enterica serotype Choleraesuis (ATCC 12011) and Pseudomonas aeruginosa (ATCC 9027) Gram-negative and compared with standard antimicrobial. The Minimum Inhibitory Concentrations (MIC) used were 25, 50, 75 and 100μɡ/mL. The results of the in vitro antibacterial activity with the inhibition halos of the selected bacterial species were analyzed on the ANOVA test, using the randomized block design, containing five treatments, in two blocks and it was possible to verify the existence of statistical difference In variables (p≤0,05). For lemongrass essential oil, especially for Staphylococcus aureus and Bacillus cereus with a concentration of 75μɡ/mL. The essential oil of the clove reached a result against Staphylococcus aureus with a concentration of 25μɡ/mL and the other bacteria Bacillus cereus, Escherichia coli and Salmonella enterica serotype Choleraesuis with 50μɡ/mL, being Pseudomonas aeruginosa at the concentration of 100μɡ/mL. Finally, the essential oil of basil at a concentration of 25μɡ/mL being active against the bacterium Staphylococcus aureus, the concentration was increased to 50mg / mL in Gram-positive Bacillus cereus and in the two Gram-negative Escherichia coli and Salmonella enterica serotype Choleraesuis, Both underwent the bactericidal action of the essential oil. The bacterium Enterococcus faecalis, despite being classified by the active inhibition halo, required a minimum concentration of the study. The essential oils were analyzed by gas chromatography and GC/MS mass spectrometry and the physicochemical parameters were determined: density, refractive index, alcohol solubility (70%), odor, color, appearance. Subsequently, the fingerprints of the minority and major components present in the different fractions of the five essential oils were identified and quantified. For this, the compounds identified by the GC/MS chemical analysis showed the presence of monoterpenes and hydrocarbon (non-oxygenated) and oxygenated sesquiterpenes, in addition to three phenylpropanoids with a diversity of low molecular weight chemical structures. Therefore, future studies aiming at the applicability of these oils as natural additives should be carried out in an attempt to increase the shelf life of foods, as well as to improve the physico-chemical characteristics and achieve the desired food safety.
Descrição
Palavras-chave
Bactérias, CGEM, Disco-difusão, Efeito antibacteriano, MIC