Caracterização química e biológica da planta aromática e medicinal Salvia officinalis L. var. purpurascens
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2017-02-15
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Na etnobotânica Portuguesa estão descritas várias plantas aromáticas e medicinais (PAM) que apresentam propriedades antioxidantes e antimicrobianas. A atividade antioxidante é atribuída a substâncias biologicamente ativas, principalmente aos compostos fenólicos, que têm efeitos benéficos na saúde humana, particularmente na redução de risco das doenças cardiovasculares e de vários tipos de cancro. O estudo da atividade antimicrobiana é de extrema importância, dado que o aumento da resistência dos microrganismos patogénicos aos antibióticos causa graves problemas de saúde pública e elevados prejuízos económicos. A espécie Salvia officinalis L. é uma PAM da família Lamiaceae que contém muitos compostos de interesse farmacológico, alguns dos quais já identificados. Assim com base nestas evidências, a presente investigação teve como objetivo principal efetuar uma caracterização morfoanatómica, fisiológica e bioquímica de Salvia officinalis L. var. purpurascens, a salva rubra, de folhas jovens e adultas ao longo dos ciclos vegetativos de 2011 e 2013, e relacionar a sua utilização com possíveis ações farmacológicas, tal como a sua importância como antioxidante e a sua atividade antimicrobiana. Neste estudo selecionaram-se plantas de Salvia officinalis L. var. purpurascens pertencentes à coleção de plantas aromáticas e medicinais existentes no Jardim Botânico da Universidade de Trás-os-Montes e Alto Douro.
Verificou-se que as folhas de salva rubra apresentam uma anatomia típica das plantas pertencentes à divisão Magnoliophyta, classe Magnoliopsida. Apresentam mesófilo heterogéneo, são dorsiventrais e com estomas reniformes de distribuição hipoestomática. Em ambas as páginas dos dois tipos de folhas surgem tricomas glandulares e não glandulares. Pela análise dos resultados é possível constatar que em resposta à ontogenia foliar, a espécie Salvia officinalis L. var. purpurascens apresentou diferenças significativas ao nível da anatomia, fisiologia e bioquímica. De facto, as folhas adultas de coloração verde apresentaram uma maior área, bem como uma maior espessura da lâmina total e dos tecidos condutores. Adicionalmente, estas folhas registaram menores condutâncias estomáticas e taxas de transpiração, melhorando a eficiência intrínseca do uso da água ao longo dos ciclos vegetativos. Verificou-se ainda uma menor peroxidação lipídica das membranas celulares de folhas adultas, que contribuíram certamente para a diminuição da perda de eletrólitos. Por outro lado, as folhas jovens de coloração púrpura registaram maior concentração de pigmentos fotossintéticos e de ceras intra e epicuticulares solúveis. Relativamente ao efeito da data de colheita, determinou-se uma maior concentração de pigmentos fotossintéticos e
amido, bem como de ceras solúveis e de suculência foliar, mas menor área foliar e concentração de açúcares solúveis em setembro. Já quanto ao efeito do ano, verificou-se uma maior concentração de pigmentos fotossintéticos e de amido e ainda de suculência foliar no ano 2011, considerado o mais quente desde 1930. Em suma, as variações nos parâmetros estudados, quer na estação do ano quer do próprio ano de colheita, sugerem uma forte influência das condições climáticas.
Relativamente aos compostos fenólicos analisados verificou-se uma clara diferenciação entre as folhas secadas e frescas, sendo estas últimas caracterizadas por uma menor quantidade de fenóis totais relativamente às amostras de folhas secadas. Verificou-se ainda que as amostras de folhas frescas apresentam uma maior uniformidade entre si, relativamente aos parâmetros em estudo (fenóis totais, orto-difenóis e flavonoides), quando comparadas com amostras secas, o que indica a existência de uma maior similaridade entre elas. A atividade antioxidante desta planta está associada à acumulação de numerosos compostos secundários e orgânicos, nomeadamente os orto-difenóis e flavonoides. Apesar de não ser possível inferir com precisão quais são os compostos responsáveis pela ação antioxidante, os orto-difenóis e os flavonoides devem ser parcialmente responsáveis por esta atividade.
A atividade antimicrobiana foi testada usando-se extratos etanólicos e hidroetanólicos, para avaliar a sua possível utilização farmacológica. Os extratos foram testados em leveduras das espécies Candida albicans (ATCC90028), Candida parapsilosis (ATCC 22019) e Candida oleophila (isolado na UTAD), e 3 bactérias das espécies Escherichia coli (0157H7607914), Staphylococcus aureus (ATCC 6538) e Listeria monocytogenes (ATCC 679). Verificou-se que o extrato em estudo inibiu apenas modestamente as espécies testadas. As espécies mais susceptíveis foram a bactéria Staphylococcus aureus e Candida parapsilosis, e as mais resistentes revelaram ser as espécies E. coli e C. albicans. Estes resultados ainda que preliminares permitem antever alguma atividade antimicrobiana, provavelmente devido aos flavonoides e orto-difenóis, que foram encontrados em maiores quantidades nesta variedade.
In Portuguese ethnobotanics, several medicinal and aromatic plants (MAP) have been described by their antioxidant and antimicrobial properties. Epidemiological studies have shown that MAP are rich in thousands of biologically active substances, namely phenolic compounds. Most of these may have the potential to provide substantial health effects, particularly in the reduction of cardiovascular diseases incidence and some types of cancer. The study of the antimicrobial activity is also of extreme importance, since microorganisms have developed resistance to antibiotics, which can cause serious public health problems. Antibiotic resistance has been called one of the World’s most burning public health problem affecting both current and future generations. The species Salvia officinalis contains many compounds of pharmacological interest, some of them already identified. Based on these evidences, this investigation aimed to make a morphoanatomical, physiological and chemical characterization of Salvia officinalis L. var. purpurascens. Therefore, we studied the composition of young and adult leaves over the growing seasons of 2011 and 2013 and relate to their use with potential pharmacological actions, such as its importance as antioxidant and antimicrobial activities. In this study we selected plants of Salvia officinalis L. var. purpurascens from the collection of medicinal and aromatic plants existing in the Botanical Garden of the University of Trás-os-Montes e Alto Douro. It was found that this sage leaves feature have a typical anatomy of plants belonging to the division Magnoliophyta, class Magnoliopsida. Have a heterogeneous mesophyll, dorsiventral and reniform stomata with hypostomatic distribution. In both pages of leaves, arise glandular and nonglandular trichomes. It was also concluded that in response to leaf ontogeny, the species Salvia officinalis L. var. purpurascens showed significant differences in the anatomy, physiology and biochemistry. From the analysis of the results, it was found that the adult leaves of this species showed a greater leaf area, a greater total lamina thickness and more vascular tissues. These leaves had a lower stomatal conductance and transpiration rates, improving the intrinsic water use efficiency of water during the growing seasons. It was also observed a lower lipid peroxidation of cell membranes of mature leaves, which certainly contributed to reducing the electrolyte leakage. On the other hand, the young leaves had a higher concentration of photosynthetic pigments and soluble cuticular waxes. Concerning the harvesting date, it was observed a higher concentration of photosynthetic pigments and starch, as well as a lower concentration in soluble waxes and leaf succulence in September. However, we found a less leaf area and lower concentration of soluble sugars in September. As for the effect of the year, there was a greater concentration of photosynthetic pigments, starch and further leaf succulence in 2011, considered the warmest year since 1930. In short, variations in the studied parameters, either on the season or the same year of harvest, suggest a strong influence of climatic conditions. About the phenolic compounds analysis, there was found a clear difference between dry and fresh leaves, being the latest characterized by a smaller amount of total phenols compared to dry ones. It was also found that samples of fresh leaves are more intrinsically similar, with respect to parameters under study (total phenols, ortho-diphenols and flavonoids), when compared with dry samples. The antioxidant activity was associated with the accumulation of numerous secondary and organic compounds, including ortho-diphenols and flavonoids. Although it is not possible to infer with precision the compounds which are responsible for the antioxidant activity, these compounds must be partly responsible for this activity. The antimicrobial activity was tested using ethanolic and hydroethanolic extracts to evaluate its possible pharmacological uses. The extracts were tested on yeasts of species Candida albicans (ATCC90028), Candida parapsilosis (ATCC 22019) and Candida oleophila (isolated in UTAD) and 3 bacteria of the species Escherichia coli (0157H7607914), Staphylococcus aureus (ATCC 6538) and Listeria monocytogenes (ATCC 679). It has been found that the extract under study inhibited only modestly the tested species. The most susceptible species were the bacteria Staphylococcus aureus and the yeast Candida parapsilosis, and the most resistant were species of E. coli and C. albicans. These results, still preliminary, allows us to suppose some antimicrobial activity, probably due to flavonoids and ortho-dyphenols, found in high concentrations in this variety.
In Portuguese ethnobotanics, several medicinal and aromatic plants (MAP) have been described by their antioxidant and antimicrobial properties. Epidemiological studies have shown that MAP are rich in thousands of biologically active substances, namely phenolic compounds. Most of these may have the potential to provide substantial health effects, particularly in the reduction of cardiovascular diseases incidence and some types of cancer. The study of the antimicrobial activity is also of extreme importance, since microorganisms have developed resistance to antibiotics, which can cause serious public health problems. Antibiotic resistance has been called one of the World’s most burning public health problem affecting both current and future generations. The species Salvia officinalis contains many compounds of pharmacological interest, some of them already identified. Based on these evidences, this investigation aimed to make a morphoanatomical, physiological and chemical characterization of Salvia officinalis L. var. purpurascens. Therefore, we studied the composition of young and adult leaves over the growing seasons of 2011 and 2013 and relate to their use with potential pharmacological actions, such as its importance as antioxidant and antimicrobial activities. In this study we selected plants of Salvia officinalis L. var. purpurascens from the collection of medicinal and aromatic plants existing in the Botanical Garden of the University of Trás-os-Montes e Alto Douro. It was found that this sage leaves feature have a typical anatomy of plants belonging to the division Magnoliophyta, class Magnoliopsida. Have a heterogeneous mesophyll, dorsiventral and reniform stomata with hypostomatic distribution. In both pages of leaves, arise glandular and nonglandular trichomes. It was also concluded that in response to leaf ontogeny, the species Salvia officinalis L. var. purpurascens showed significant differences in the anatomy, physiology and biochemistry. From the analysis of the results, it was found that the adult leaves of this species showed a greater leaf area, a greater total lamina thickness and more vascular tissues. These leaves had a lower stomatal conductance and transpiration rates, improving the intrinsic water use efficiency of water during the growing seasons. It was also observed a lower lipid peroxidation of cell membranes of mature leaves, which certainly contributed to reducing the electrolyte leakage. On the other hand, the young leaves had a higher concentration of photosynthetic pigments and soluble cuticular waxes. Concerning the harvesting date, it was observed a higher concentration of photosynthetic pigments and starch, as well as a lower concentration in soluble waxes and leaf succulence in September. However, we found a less leaf area and lower concentration of soluble sugars in September. As for the effect of the year, there was a greater concentration of photosynthetic pigments, starch and further leaf succulence in 2011, considered the warmest year since 1930. In short, variations in the studied parameters, either on the season or the same year of harvest, suggest a strong influence of climatic conditions. About the phenolic compounds analysis, there was found a clear difference between dry and fresh leaves, being the latest characterized by a smaller amount of total phenols compared to dry ones. It was also found that samples of fresh leaves are more intrinsically similar, with respect to parameters under study (total phenols, ortho-diphenols and flavonoids), when compared with dry samples. The antioxidant activity was associated with the accumulation of numerous secondary and organic compounds, including ortho-diphenols and flavonoids. Although it is not possible to infer with precision the compounds which are responsible for the antioxidant activity, these compounds must be partly responsible for this activity. The antimicrobial activity was tested using ethanolic and hydroethanolic extracts to evaluate its possible pharmacological uses. The extracts were tested on yeasts of species Candida albicans (ATCC90028), Candida parapsilosis (ATCC 22019) and Candida oleophila (isolated in UTAD) and 3 bacteria of the species Escherichia coli (0157H7607914), Staphylococcus aureus (ATCC 6538) and Listeria monocytogenes (ATCC 679). It has been found that the extract under study inhibited only modestly the tested species. The most susceptible species were the bacteria Staphylococcus aureus and the yeast Candida parapsilosis, and the most resistant were species of E. coli and C. albicans. These results, still preliminary, allows us to suppose some antimicrobial activity, probably due to flavonoids and ortho-dyphenols, found in high concentrations in this variety.
Descrição
Tese de Doutoramento em Ciências da Terra e da Vida
Palavras-chave
Salvia officinalis , Anatomia foliar , Troca gasosa , Metabolito , Atividade antioxidante , Atividade antimicrobiana