Evaluation of basil extract ( Ocimum basilicum L. ) on oxidative, anti-genotoxic and anti-inflammatory effects in human leukocytes cell cultures exposed to challenging agents

ABSTRACT Ocimum is one of the most important genera of the Lamiaceae family. Several studies about basil and its popular use reveal many characteristics of the herb, including its use as antioxidant, anti-aging, anti-inflammatory, anti-carcinogenic, anti-microbial, and cardiovascular agents, among others. In this paper, we evaluated genotoxic, oxidative, and anti-inflammatory parameters from the extract of Ocimum basilicum in different concentrations, using human leukocytes cultures exposed to challenging agents. Our results confirm that the O. basilicum extract acts as an antioxidant and effectively reverts or subjugates the effects of high oxidizing agents such as hydrogen peroxide. These actions are attributed to its composition, which is rich in polyphenols and flavonoids as well as compounds such as rosmarinic acid, all of which have well-known antioxidant activity. We also show that our basil extract presents anti-inflammatory properties, the mechanism of which is a composed interaction between the inhibition of pro-inflammatory mediator and the stimulation of anti-inflammatory cytokines. Although pharmacodynamics studies are necessary to evaluate the activities in vivo, our results demonstrated that basil could act as an antioxidant and anti-inflammatory and a possible alternative for medicinal treatment.

Atividade antibacteriana de Óleos Essenciais sobre Streptococcus mutans e Staphylococcus aureus / Antibacterial Activity of Essential Oils against Strains of Streptococcus and Staphylococcus

Este trabalho objetivou avaliar a ação antimicrobiana in vitro dos óleos essenciais de Ocimum basilicum (Manjericão Exótico), Thymus vulgaris (Tomilho Branco), e de Cinnamomum cassia (Canela da China) sobre cepas bacterianas de Streptococcus mutans (ATCC 25175) e Staphylococcus aureus (ATCC 25923). A atividade antibacteriana dos óleos essenciais foi determinada pela Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) através da técnica de microdiluição e do esgotamento. Para a CIM, foram utilizadas placas de 96 poços e inseriu-se 100µL de caldo BHI, 100µL da diluição dos óleos essenciais no primeiro poço e 10µL da suspensão bacteriana (1,5x10(6) microrganismos/mL). Realizou-se a diluição seriada partindo-se da concentração inicial de 8% até 0,0625%. A CIM correspondeu à última diluição na qual não foi verificada a presença de bactérias. Para obter a CBM, realizou-se a semeadura em Ágar Miller-Hinton das diluições correspondentes a CIM, 2CIM e 4CIM. As placas foram incubadas a 37º C em estufa bacteriológica por 24 horas. Os testes foram realizados em triplicata tendo a clorexidina como controle positivo. Para S. aureus (ATCC 25923) a CIM e CBM dos óleos essenciais de C. cassia, O. basilicum e T. vulgaris foram 0,0625%, 4% e 0,0625%, respectivamente. Para S. mutans a CIM e a CBM dos óleos essenciais de C. cassia e T. vulgaris foram 0,125% e 0,25%, respectivamente. Já a CIM do O. basilicum foi 4% e não apresentou ação bactericida. Conclui-se que os óleos essenciais avaliados apresentaram ação antibacteriana frente a cepas de S. mutans e S. aureus, sendo que os menores valores de CIM e de CBM foram provenientes dos óleos de C. cassia e T. vulgaris.

The aim of this study is to evaluate the in vitro antimicrobial activity of essential oils of Ocimum basilicum (basil), Thymus vulgaris (thyme) and Cinnamomum cassia (Chinese cinnamon) against strains of Streptococcus mutans (ATCC 25175) and Staphylococcus aureus (ATCC 25923). The antibacterial activity of the essential oils was determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The MIC was obtained by the microdilution technique using 96-well microplates, in which we inserted: 100µL of Brain Heart Infusion broth at double concentration, 100µL of the dilution of the essential oils and 10µL of bacterial suspension (1.5 x 10(6) organisms / mL). The products were diluted from the initial concentration of 8% up to 0.0625%. The MIC corresponded to the last dilution in which there was no presence of bacteria or turbidity in the culture medium. The MBC was obtained by seeding, in Mueller-Hinton agar, 10µL aliquots of dilutions corresponding to the MIC and the two immediately preceding ones (2MIC and 4MIC). The plates were incubated at 37°C in a bacteriological incubator for 24 hours. The tests were performed in triplicate, and 2% Chlorhexidine Digluconate was the control product. For S. aureus, the MIC and MBC of the essential oils of C. cassia, O. basilicum and T. vulgaris were 0.0625%, 0.0625% and 4%, respectively. For S. mutans, the MIC and MBC of the essential oils of C. cassia and T. vulgaris were 0.125% and 0.25%, respectively. The MIC of O. basilicum against S. mutans was 4% and the essential oil showed no bactericidal action. Chlorhexidine Digluconate presented antibacterial activity against all organisms. The evaluated essential oils presented antibacterial activity against the strains of S. mutans and S. aureus, and we highlight the essential oils from C. cassia and T. vulgaris with the lowest MIC and MBC.

Atividade antifúngica de óleos essenciais frente a amostras clínicas de Candida albicans isoladas de pacientes HIV positivos / Antifungal activity of essential oils against clinical samples of Candida albicans isolated from HIV-positive patients

Objetivou-se avaliar a atividade antifúngica dos óleos essenciais de Ocimum basilicum L. (manjericão), Cymbopogon martinii L. (palmarosa), Thymus vulgaris L. (tomilho) e Cinnamomum cassia Blume (canela da china) sobre cepas de Candida albicans isoladas de pacientes HIV positivos e cepa padrão (ATCC 76845). Quinze amostras clínicas de C. albicans (C1-C15) foram repicadas em ágar Sabouraud Dextrose, para confecção de suspensões em solução salina estéril (0,9%) contendo 1,5 x 10(6) UFC mL-1. As emulsões dos óleos essenciais foram preparadas em água destilada estéril e tween 80, com concentrações variando entre 1024 µg mL-1 e 4 µg mL-1. A ação antifúngica foi determinada por meio da Concentração Inibitória Mínima (CIM) utilizando-se a técnica da microdiluição. Foram utilizados como controles positivos a nistatina e o miconazol (50 µg mL-1). Os testes foram realizados em triplicata, sendo a CIM, a menor concentração capaz de inibir o crescimento das leveduras, observada por método visual de acordo com a turvação do meio de cultura. Para C. albicans (ATCC 76845), a CIM do óleo essencial de C. cassia foi 64 µg mL-1, enquanto para óleo de C. martinii foi 1024 µg mL-1. Para as cepas clínicas, verificou-se que a CIM de C. cassia para 80% das cepas foi 64 µg mL-1, sendo a variação dos valores da CIM entre 128 µg mL-1 e 64 µg mL-1. Observou-se que para 66,6% das amostras clínicas, a CIM de C. martinii foi 612 µg mL-1. Constatou-se que a nistatina não apresentou atividade frente às cepas clínicas (C1-C15), enquanto a atividade antifúngica do miconazol foi verificada em 100% das amostras. Não se constatou atividade antimicrobiana dos óleos essenciais de O. basilicum e T. vulgaris, nas concentrações avaliadas. Concluiu-se que os óleos essenciais de C. cassia e C. martinii, em diferentes concentrações, apresentam atividade antifúngica sobre cepas de C. albicans isoladas de pacientes HIV positivos e cepa padrão (ATCC 76845). Entretanto não foi observada inibição antimicrobiana para os óleos de O. basilicum e T. vulgaris.

The aim of this study was to evaluate the antifungal activity of essential oils from Ocimum basilicum L. (basil), Cymbopogon martinii L. (palmarosa), Thymus vulgaris L. (thyme) and Cinnamomum cassia Blume (Chinese cinnamon) against Candida albicans strains isolated from HIV-positive patients and the standard strain (ATCC 76845). Fifteen clinical samples of C. albicans (C1-C15) were subcultured in Sabouraud Dextrose agar to prepare suspensions in sterile saline solution (0.9%) containing 1.5 x 10(6) CFU mL-1. The emulsions of essential oils were prepared in sterile distilled water and Tween 80, with concentrations ranging between 1024 µg mL-1 and 4 µg mL-1. The antifungal action was determined by means of the Minimum Inhibitory Concentration (MIC), using the microdilution technique. Nystatin and miconazole (50 µg mL-1) were used as positive controls. The tests were performed in triplicate and the MIC was the lowest concentration capable of inhibiting the growth of yeasts, which was observed by the visual method, according to the turbidity of the culture medium. For C. albicans (ATCC 76845), the MIC of C. cassia essential oil was 64 µg mL-1, while the MIC for C. martini was 1024 µg mL-1. Considering the clinical strains, the MIC of C. cassia was 64 µg mL-1 for 80% of the strains, and the variation in MIC values was between 128 µg mL-1 and 64 µg mL-1. For 66.6% of the clinical samples, the MIC of C. matinii was 612 µg mL-1. Nystatin did not present activity against the clinical strains (C1-C15), while the antifungal activity of miconazole was noticed for 100% of the samples. The antimicobrial activity of essential oils from O. basilicum and T. vulgaris was not identified at the evaluated concentrations. It was concluded that the essential oils from C. cassia and C. martinii, at different concentrations, presented antifungal activity against C. albicans strains isolated from HIV-positive patients and the standard strain (ATCC 76845). However, antifungal activity was not observed for the essential oils from O. basilicum and T. vulgaris.