Chemical composition and pharmacological activities of essential oils of Lavandula spp.

Lavandula spp. belong to the family Lamiatae and some species are often used in popular medicine and have been used for centuries in a large number of medical applications and in aromatherapy. Although similar ethnobotanical properties of Lavandula spp., its essential oils, general chemical composition and therapeutic applications differ from different species. Lavandula stoechas L. subsps. luisieri (Rozeira) Rozeira and L. viridis L’Hér are endemic to the Iberian Peninsula, widespread in the South of Portugal, namely in Southern Alentejo and Algarve. The aim of our study was evaluate the chemical composition and toxicological and pharmacological activities of leaves essential oils of spontaneous plants of L. stoechas L. subsps. luisieri (Alentejo) and L. viridis (Algarve). The essential oils of these wild plants, collected in spring, were obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was evaluated by GC/FID. The acute toxicity of essential oils was evaluated "in vitro" using brine shrimp (LC50) and "in vivo" using Swiss mice (DL50). The analgesic and anti-inflammatory pharmacological properties of L. stoechas subsp. luisieri essential oil were evaluated in mouse or rats by the Amour-Smith and carrageen-induced paw edema tests, respectively. Results showed important differences in chemical composition of essential oils from two species analyzed either to diversity and proportion of its constituents. The essentials oils showed citotoxicity against Artemia salina and a DL50 higher than 2000 mg/kg for mice. The analgesic and anti-inflammatory activities of essential oils were exhibit for the doses of 100 and 200 mg/kg.

Antioxidant,antimicrobial and toxicological properties of Schinus molle L. essential oils

Ethnopharmacological relevance: Schinus molle L. has been used in folk medicine as antibacterial, antiviral, topical antiseptic, antifungal, antioxidant, anti-inflammatory, anti-tumoural as well as antispasmodic and analgesic; however, there are few studies of pharmacological and toxicological properties of S. molle essential oils. Aim of the study: The aim of this study was to evaluate the antioxidant and antimicrobial activities of S. molle leaf and fruit essential oils, correlated with their chemical composition and evaluate their acute toxicity. Materials and methods: The chemical composition of S. molle leaf and fruit essential oils were evaluated by GC-FID and GC-MS. Antioxidant properties were determined using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical and β-carotene/linoleic acid methods. Antimicrobial properties were evaluated by the agar disc diffusion method and minimal inhibitory concentration assay. Toxicity in Artemia salina and acute toxicity with behavioural screening in mice were evaluated. Results: The dominant compounds found in leaf and fruit essential oils (EOs) were monoterpene hydrocarbons, namely -phellandrene, β-phellandrene, β-myrcene, limonene and α-pinene. EOs showed low scavenging antioxidant activity by the DPPH free radical method and a higher activity by the β-carotene/linoleic acid method. Antimicrobial activity of EOs was observed for Gram+, Gram– pathogenic bacteria and food spoilage fungi. EOs showed cytotoxicity for Artemia salina and lower toxicity in Swiss mice. Conclusions: The result showed that EOs of leaves and fruits of S. molle demonstrated antioxidant and antimicrobial properties, suggesting their potential use in food or pharmaceutical industries.

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.

Caracterização química e actividade biológica dos óleos essenciais e extractos aquosos de algumas Lavandula spp. do Sul de Portugal

No presente trabalho estudaram-se três espécies do género Lavandula, do sul de Portugal: L. luisieri e L. pedunculata (Alentejo) e L.viridis (Algarve), com vista caraterizar a composição química dos óleos essenciais das diferentes espécies, parte vegetativa (folha) e espiga floral, e dos respetivos extratos de hidrodestilação, e avaliar as propriedades antioxidante, antimicrobiana, toxicológica, analgésica e antiinflamatória de alguns dos seus óleos essenciais e extratos aquosos, mais promissores. Os resultados mostraram importantes diferenças na composição química dos óleos essenciais, quanto à diversidade e à proporção dos seus constituintes. Os óleos essenciais e hidrolatos, em estudo, apresentaram importantes propriedades antioxidantes e antimicrobianas. Os estudos toxicológicos e farmacológicos mostraram que os óleos apresentaram citotoxicidade em Artemia salina, apresentaram valores de DL50 muito superiores a 2000 mg/kg em ratinhos Swiss, e que possuem importantes propriedades analgésicas e anti-inflamatória. Estes resultados sugerem o seu potencial uso para aplicações farmacológicas como agentes nutracêuticos e/ou fitoterapêuticos; ABSTRACT:The aim of present work was to develop a set of studies of three species of the genera Lavandula, at the South of Portugal: L. luisieri e L. pedunculata (Alentejo) e L.viridis (Algarve), in order to characterize the chemical composition of the essential oils (leaves and flowers) and to evaluate the antioxidant, antimicrobial, toxicological and pharmacological properties of selected essential oils and aqueous extracts. Results show important differences in chemical composition of essential oils, both in diversity as the proportion of their constituents. Essential oils and aqueous extracts of different Lavandula spp. showed important antimicrobial and antioxidant properties. Pharmacological studies have shown that essential oils showed cytotoxicity against Artemia salina, low acute toxicity, with LD50 >> 2000 mg/kg for mice, and important analgesic and anti-inflammatory properties. These results suggest their potential use for pharmacological applications as nutraceutical and/or phytotherapeutic agents.

A formação inicial e desenvolvimento profissional de educadores/professores monodocentes: os desafios do isomorfismo pedagógico

Neste texto trazemos a campo uma reflexão sobre o modo como concebemos a docência e desenvolvemos o trabalho na formação inicial e contínua de educadores-professores na Universidade de Évora. Fazemo-la a partir das nossas vivências e práticas, na formação inicial e contínua de educadores de infância (EI) e professores do 1º Ciclo do Ensino Básico (1º CEB) ao longo dos últimos quinze anos. Invocamos a nossa participação enquanto membros integrados numa equipa mais alargada de docentes, partilhando a adequação do que vamos fazendo face ao perfil de educador/professor para o qual pretendemos contribuir, não apenas porque ele está legislado, mas também porque nos pautamos pela mais recente investigação em educação infantil, perseguindo nesta etapa da construção da profissionalidade docente, aquelas que consideramos serem as mais prementes necessidades da sociedade no séc. XXI. Focalizamos esta reflexão no caso particular dos educadores de infância (professores da educação infantil dos 0 aos 6 anos) e dos professores do 1.º ciclo do ensino básico (CEB) (1ª a 4ª série do ensino fundamental dos 6 aos 10 anos), ou seja, monodocentes porque são professores que se encarregam das aprendizagens curriculares das crianças contemplando várias áreas do saber, cuja abordagem integradora é da sua responsabilidade. Iniciamos com uma breve apresentação, daqueles que pensamos serem os desafios do mundo atual que se colocam aos professores e à sua formação profissionalizante. Fundamentamos a nossa análise da formação inicial de educadores/professores na Teoria da Atividade (TA) de Leontiev (1978), mais tarde desenvolvida por Engeström (2001), entre outros, a partir das ideias de Vygostsky (1994). Partindo do pressuposto que a aprendizagem se dá por um processo de participação em práticas sociais que contêm o conhecimento construído ao longo da história dos homens, recorremos ao conceito de isomorfismo pedagógico (Niza, 2009) para (re)pensar os contextos e os processos em que os estudantes de formação de professores se apropriam e constroem o conhecimento profissional. Nesta partilha sobre a formação para a docência evidenciamos igualmente a importância das interacções que mantemos com o Movimento da Escola Moderna (MEM) portuguesa, um movimento de professores com um património único na construção do saber profissional: “O Movimento da Escola Moderna tem procurado investir a experiência dos professores, do ponto de vista teórico e conceptual, contribuindo para o desenvolvimento científico da profissão docente” (Nóvoa, 1992, p. 25 ). Apontamos assim para as opções estratégicas que temos vindo a desenvolver no sentido de procurar o isomorfismo pedagógico, capaz de sustentar esta formação de educadores/professores, de os estimular para um papel novo no contexto actual e de, enquanto docentes neste percurso profissionalizante, nos desafiarmos a reflexões permanentes em desejadas e construções de conhecimento tornadas possíveis porque realizadas em conjunto com os nossos alunos, docentes cooperantes e parcerias institucionais.