Chemical composition, antioxidant, and antimicrobial activities of six commercial essential oils.

Essential oils (EOs) and their components extracted from medicinal and aromatic plants are used in several areas, such as perfumery and chemical, cosmetic, food, and pharmaceutical industries. Considering the different applications of EOs, this work aimed to screen the composition and the bioactivities properties of the EOs of Foeniculum vulgare, Helichrysum stoechas, Mentha pulegium, Pinus pinaster, Ruta graveolens, and Thymus mastichina. Gas chromatography-mass spectrometry revealed the presence of different compounds in EOs F. vulgare (12), H. stoechas (27), M. pulegium (8), P. pinaster (24), R. graveolens (8), and T. mastichina (16). All the EOs showed antioxidant activity acting through inhibition of lipid peroxidation, while only two EOs (H. stoechas and M. pulegium) scavenged the free radicals of DPPH. Mentha pulegium and T. mastichina EOs showed the strongest antimicrobial activity. Also, the effect on the fibroblast's viability was directly proportional to the EOs concentration, and the highest cytotoxic effect was registered with R. graveolens EO. The present study revealed significant bioactive properties of different EOs, highlighting M. pulegium and T. mastichina EOs to be considered in further studies for potential use in the food and pharmaceutical industries, due to their antioxidant and antimicrobial properties.

Melissa officinalis essential oil as an antimicrobial agent against Listeria monocytogenes in watermelon juice.

The burden of foodborne illness has a negative effect on public health, but also in countries' economy. Melissa officinalis is an aromatic plant known for its biological properties, including antioxidant and antimicrobial effects. This work highlighted M. officinalis essential oil's antioxidant potential and antimicrobial activity against L. monocytogenes, presenting a bactericidal action and being able to inhibit some virulence attributes, such as biofilm formation. The pre-exposure of the bacterium to subinhibitory levels of essential oil (0.125 µL/mL) did not induce high tolerance to stresses (such as high temperature, low pH, osmotic stress and desiccation) or cross-resistance with antibiotics, while not modifying the invasion ability to Caco-2 cells. When applied in food model media (lettuce, chicken and milk) and watermelon juice, the essential oil showed to have antimicrobial activity in a lettuce leaf model medium, further diminishing L. monocytogenes contamination and inhibiting the natural microbiota present in watermelon juice. M. officinalis essential oil shows potential to be used as control of L. monocytogenes in watermelon juice, while increasing the food's microbial shelf life.

Phytochemical Characterization, Bioactivities Evaluation and Synergistic Effect of Arbutus unedo and Crataegus monogyna Extracts with Amphotericin B.

The increased resistance to drugs by pathogens is a serious problem, with plants showing to be promising sources for the development of new drugs or the improvement of the effect of existing antimicrobial agents. Considering this, we aimed to evaluate the bioactivities of Arbutus unedo and Crataegus monogyna. Thus, the leaves were first extracted with methanol and then fractionated with different solvents. Phenolic compound profiles were assessed by HPLC-PDA-MSn and the antioxidant activity was evaluated using DPPH method and ß-carotene bleaching assay. The antimicrobial activity of extracts was tested against several microorganisms. A. unedo contained mainly galloyl esters, hydrolysable tannins, and flavonoids, while in C. monogyna, 5-caffeoylquinic acid and flavonoids were the most representative polyphenols. Crude extracts showed antioxidant activity and the extracts and fractions displayed a weak antibacterial activity; however inhibiting the growth of Candida tropicalis and C. lusitaniae to which A. unedo extract showed higher activity. Most of the extracts and fractions demonstrated synergistic or additive interactions with amphotericin B against Candida spp. Therefore, the present study revealed significant bioactive properties of the extracts and fractions of A. unedo and C. monogyna, such as antioxidant and antifungal activities.

Biological properties of Thymus zygis essential oil with emphasis on antimicrobial activity and food application.

The Thymus plants have been used for centuries in traditional medicine and as a food spice, among this genus, Thymus zygis (red thyme) is a widespread plant, vastly used as a culinary flavouring agent. Its essential oil has demonstrated diverse bioactive properties, such as antimicrobial, insecticidal, larvicidal and antiparasitic activities. Numerous studies have characterized this essential oil showing that it possesses a broad antimicrobial spectrum and may even enhance the effect of certain antimicrobial agents. Its potential application as a food preservative has been analysed on different matrixes pointing to its antimicrobial activity against spoilage and pathogenic microorganisms in food. This review provides an insight in the chemical composition, antimicrobial, insecticidal, larvicidal and antiparasitic activities and toxicity of T. zygis essential oil, as well as its potential application in food as a preservative.

Thymus zygis Essential Oil: Phytochemical Characterization, Bioactivity Evaluation and Synergistic Effect with Antibiotics against Staphylococcus aureus.

Staphylococcus aureus is a nosocomial bacterium causing different infectious diseases, ranging from skin and soft-tissue infections to more serious and life-threatening infections such as sepsis, meningitis and endocarditis, which may be exacerbated by antibiotic resistance. Plant products may be seen as an alternative as antibacterial agents, namely, against S. aureus. Thus, the aim of this work was to characterize the chemical composition and evaluate the bioactive properties of the T. zygis essential oil (EO), with a focus on antimicrobial activity against S. aureus. Gas chromatography coupled with mass spectrometry was used to assess the chemical composition of the T. zygis EO, and the antioxidant activity was evaluated using the DPPH method and ß-carotene-bleaching assay. The antimicrobial activity against S. aureus strains, the interaction with different antibiotics and the attenuation of this bacterium's virulence were evaluated. The T. zygis EO showed antioxidant activity acting through two different mechanisms and antibacterial activity against S. aureus, with antibiofilm and antihaemolytic properties. This EO also demonstrated synergistic or additive interactions in combination with ampicillin, ciprofloxacin or vancomycin against S. aureus strains and, in some cases, changed the antibiotic-resistance phenotype from resistant to susceptible. Therefore, the present work demonstrates the good bioactive properties of the EO of T. zygis, mainly the antimicrobial activity against S. aureus, revealing its potential to be used as an antibacterial agent.

Genus Ruta: A natural source of high value products with biological and pharmacological properties.

ETHNOPHARMACOLOGICAL RELEVANCE: Ruta genus is constituted by ten species, of which the most commonly described are R. chalepensis and R. graveolens. Ruta plants are perennial shrubs belonging to the family Rutaceae, which are traditionally used in folk medicine, since ancient times mostly for the treatment of various ailments of the womb. AIM OF THE STUDY: To provide a review of the different uses of Ruta species in traditional medicine, as well as, on their multifactorial biological and pharmacological properties. MATERIAL AND METHODS: A search of the literature on genus Ruta and Ruta species was performed using various scientific databases and search engines and the information of articles were reviewed and compiled. RESULTS: Different parts of the plants belonging to Ruta genus are used in folk medicine to treat a wide range of different diseases. The principal use of these is in gynaecological field, but the treatment of pain, fever, nausea, inflammation, infections, nervous disorders, among others, are also described. These plants have been used to fertility regulation, as anti-fertility agent, to control menstrual flux and bleedings, as abortifacient and as contraceptive. The phytochemical composition of these plants consists mainly in essential oil (EO), but phenolic compounds were also reported, like coumarins and flavonoids, as well as alkaloids. Ruta species products like extracts and EOs have shown broad pharmacological activities, such as antimicrobial and antifungal activities, as well as, antiviral and antiparasitic. Moreover, Ruta plants products present antioxidant, neuroprotective, anti-inflammatory, anti-cancer and anti-diabetic activities and demonstrated contraceptive and abortifacient effects. These plants were also tested to be used for non-therapeutic approaches, as bio-insecticides in the control of different insect pests showing to be able to reduce infestation. CONCLUSIONS: Ruta species could be a potential source of natural products with biological activities. Ruta extracts, essential oils and isolated compounds have shown a diverse potential for use in the treatment of different diseases, as well as, for pests control, contributing to the valorisation of these plants. Nonetheless, this review indicates that more studies are needed to demonstrate the full potential of Ruta species, and to further explore the toxicology and safety of these plants.

A Case of Brucellosis with Possible Ileal Involvement.

INTRODUCTION: Brucellosis is a zoonotic disease that can involve different organs and tissues. Fever, fatigue, lymphadenopathy, hepatosplenomegaly, cytopenia, and arthritis are the usual modes of presentation. Gastrointestinal manifestations of human brucellosis are common but documented ileal involvement is extremely rare. CASE DESCRIPTION: A 68-year-old female presented with a history of 10 days of intense temporal migraine, photophobia, and phonophobia with partial response to paracetamol. The patient referred night sweats, anorexia, and colicky abdominal pain after her meals for the past 4 months followed by diarrhea. She denied nausea, vomiting, hypersensitivity of the scalp, blurry vision, melena, or rectal bleeding. She denied travelling or contact with animals. Physical examination revealed fever (38.3°C) and splenomegaly. Laboratory workup revealed Hb 7.8 g/dL, leukopenia (3.47 × 109/L), C-reactive protein 5.94 mg/dL, and erythrocyte sedimentation rate 23 mm/h. Abdominal ultrasound showed hepatic steatosis and mild homogeneous splenomegaly. Chest radiography was normal. Lumbar puncture; transcranial, carotid, and temporal arteries Doppler, and head computed tomography (CT) did not show any significant changes. Abdominal CT showed diffuse thickening of the ileum and some mildly swollen locoregional lymph nodes. Fecal calprotectin was not elevated. Blood cultures and serologies were positive for Brucella (positive Rose-Bengal test, ELISA IgM-positive, IgG-negative anti-brucella antibody serology and positive Huddleson reaction - titer 1:320). The patient was started on rifampicin 600 mg/day and doxycycline 100 mg q. 12 h for 10 weeks with good clinical and analytical response. Upper and lower gastrointestinal endoscopy were normal, although the last was done already under antibiotic treatment. DISCUSSION: Although gastrointestinal manifestations of brucellosis are quite common, ileitis is thought to be extremely rare. In countries where brucellosis is endemic, doctors must consider this diagnosis when faced with patients with systemic symptoms and diarrhea or abdominal pain. Early recognition of brucellosis and institution of appropriate therapy usually leads to a good recovery without complications.

INTRODUÇÃO: A brucelose é uma zoonose que pode envolver diferentes órgãos e tecidos. A apresentação habitual consiste em febre, cansaço, linfadenopatias, hepatoesplenomegalia, citopenias ou artrite. As manifestações gastrointestinais de brucelose humana são comuns, mas a documentação do envolvimento ileal é extremamente rara. DESCRIÇÃO DO CASO: Doente de 68 anos, sexo feminino, apresentouse com quadro com dez dias de evolução de cefaleia temporal intensa, fotofobia e sonofobia, com resposta parcial a terapêutica com paracetamol. A doente referia sudorese noturna, anorexia e dor abdominal tipo cólica após as refeições durante os últimos quatro meses seguida de diarreia. Negava náuseas, vómitos, hipersensibilidade do escalpe, visão turva, melenas ou retorragia. Negava viagens ou contacto com animais. Ao exame objetivo destacavase febre (38,3 ° C) e esplenomegalia. Os estudos laboratoriais revelaram Hb 7,8 g/dL, leucopenia (3,109 × 47/L), proteína C-reativa 5,94 mg/dL, velocidade de sedimentação 23 mm/h. A ecografia abdominal mostrou ligeiro aumento do fígado (estatose) e esplenomegalia ligeira e homogénea. Radiografia de tórax normal. Punção lombar; Doppler transcraniano, carotídeo e das artérias temporais e tomografia computorizada (CT) craniana sem alterações significativas. A CT abdominal mostrou espessamento difuso do íleon e algumas pequenas adenopatias locorregionais. As hemoculturas e serologias foram positivas para Brucela (Rosa Bengala positivo, serologia anti-Brucela ELISA IgM-positivo, IgG-negativo; reação de Huddleson positiva - título 1: 320). Foi iniciada terapêutica com rifampicina 600 mg/dia e doxiciclina 100 mg de 12 em 12 h durante 10 semanas com boa resposta clínica e laboratorial. Endoscopia digestiva alta e baixa sem alterações, apesar de a última ter sido realizada já sob terapêutica antibiótica. DISCUSSÃO: Embora as manifestações gastrointestinais de brucelose sejam comuns, pensase que a ileíte seja extremamente rara. Em países onde a brucelose é endémica, os médicos devem considerar esta hipótese diagnóstica quando na presença de sintomas sistémicos e diarreia ou dor abdominal. O reconhecimento precoce da brucelose e a instituição de terapêutica adequada levam geralmente a uma boa recuperação sem complicações.