CHEMICAL COMPOSITION AND ANTIMICROBIAL ACTIVITY OF ESSENTIAL OILS OF LAVANDULA SPP.

Lavenders belong to the family Labiatae and represent some of the most popular medicinal plants of great economic importance. Their essential oils are important for the perfume, cosmetic, flavouring and pharmaceutical industries. However, despite its popularity, and the long tradition of use, biological properties of the various Lavandula species are not yet been well sustained by scientific or clinical studies and some available data being inconclusive and controversial [1]. Although Lavandula spp. have similar ethnobotanical properties, however, chemical composition and therapeutic uses differ from different species and main composition of essential oils showed differences with species and with the region were they grow [1,2,3]. L. stoechas L. subsps. luisieri (Rozeira) Rozeira. L. pedunculata (Mill.) Cav. and L. viridis L’Hér are endemic to the Iberian Peninsula, widespread in the South of Portugal, namely in Alentejo and Algarve. In our work, essential oils from the stems or leaves from wild grown plants of L. luisieri (Alentejo), L. pedunculata (Alentejo) and L. viridis (Algarve), were extracted by hydrodistillation and analyzed by GC-FID. Antimicrobial activity was evaluated by solid diffusion disk assay and minimal inhibitory concentration (MIC) against pathogenic Gram-positive and Gram-negative bacteria and food spoilage fungi.

ANTIOXIDANT, ANTIMICROBIAL AND TOXICOLOGICAL PROPERTIES OF SCHINUS MOLLE L. ESSENTIAL OILS

Schinus molle L. is commonly known as pink pepper or American pepper, of Anacardiaceae family, from subtropical regions of South America, introduced and naturalized in South Europe, including Portugal. In folk medicine, plant extracts and essential oil has related as having antibacterial, antiviral, antifungal, anti-inflammatory, antitumoral, antispasmodic, analgesic and antidepressive properties. The aim of present study was to evaluate the chemical composition and biological activities of essential oil extracted from leaves and fruits of S. molle. For this purpose, the essential oils were analyzed by gas chromatography (GC/FID) and antioxidant properties were evaluated by the free radical DPPH and by system β-carotene/linoleic acid methods. The antimicrobial activities were screened against pathogenic bacteria and fungi and food spoiling fungi by the disc diffusion assay and minimal inhibitory concentration (MIC) was determined for sensitive strains. Toxicity of essential oils were carried out by the brine shrimp mortality test (EC50) and acute lethal dose (DL50) determination after oral administration in Swiss mice The major components in leaf essential oil were α-phellandrene, β-phellandrene and limonene, while myrcene, α-phellandrene and 1,8-cineole are the main components in the fruit essential oil. The essential oils of leaf and fruit of S. molle showed antioxidant activity through the two mechanisms: the ability to capture free radicals and protection of lipid peroxidation. These oils exhibited also a broad microbial activity spectrum, against pathogenic bacteria Gram-positive and Gram-negative and Candida spp. The fruit essential oil showed high cytotoxicity against Artemia salina. Essential oils of leaves and fruits of S. molle showed significant antioxidant and microbial properties, so the studies continue to clarify more in deep its toxicity, including hepatotoxicity and nephrotoxicity, and to evaluate its medicinal or nutraceutical potential.

Endotoxinas bacterianas versus resposta inflamatória e alérgica

Endotoxinas bacterianas são lipopolissacáridos da membrana externa das bactérias Gram-negativas e são responsáveis pela libertação de citocinas no organismo humano. Estas citocinas podem exacerbar a sintomatologia de determinadas patologias, nomeadamente do foro pulmonar, agravando a sua situação clínica. A procura de melhor conforto habitacional, com a criação de micro ambientes "artificiais" dentro de casa, oferece bem-estar, mas por vezes arrasta consigo uma maior quantidade de poluentes aéreos indoor, nomeadamente bioaerossóis. A influência das bactérias Oram­ negativas em suspensão indoor nos níveis basais dos marcadores analíticos sanguíneos de resposta inflamatória e alérgica, é um ponto importante a ter em consideração quando se pretende elevar o grau de conforto de uma habitação sem implicações negativas para a saúde humana. Este estudo demonstra que a presença das endotoxinas bacterianas indoor, na ausência de patologia aguda, não prejudica o ser humano e a melhoria das condições habitacionais não degrada o estado fisiológico dos indivíduos. /Summary: Bacterial endotoxins are lipopolysaccharides found in the outer membrane of Gram­ negative bacteria and are responsible for the release of cytokines in the human body. These cytokines may exacerbate the symptoms of certain diseases, including pulmonary events, worsening their medical condition. The demand for better housing comfort with the creation of "artificial" micro-environments in the house, offers well-being, but often brings a greater quantity of indoor air pollutants, including bioaerosols. The influence of suspended indoor Gram-negative bacteria in basal levels of blood analytical markers of inflammatory and allergic rhinitis, is an important point to consider when attempting to raise the comfort level of a dwelling without negative implications for human health. This study proves that the presence of indoor bacterial endotoxin in the absence of acute pathology, do not affect humans and the improvement of living conditions does not degrade the physiological status of individuals.