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Contribuição para o estudo morfológico e químico de Calycobolus heudelotii
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Calycobolus heudelotii (Baker ex Oliv.) Heine é uma liana pertencente à família Convolvulaceae, com utilização na medicina tradicional da Guiné-Bissau e outros países africanos.
Na Guiné-Bissau, o caule da liana é utilizado sob a forma de decocto, no tratamento de inflamações, alergias cutâneas e na desinfecção de feridas.
Neste trabalho apresentam-se os resultados de um estudo morfológico, químico, biológico e toxicológico efectuado de forma a contribuir para o melhor conhecimento desta planta medicinal africana.
A metodologia utilizada integrou a análise macroscópica e microscópica do caule de C. heudelotii, a avaliação da toxicidade aguda e a determinação da actividade antimicrobiana in vitro do seu extracto metanólico, assim como o rastreio dos principais constituintes químicos presentes neste extracto e sua actividade antioxidante.
Os estudos botânicos permitiram caracterizar a estrutura anómala desta liana, apresentando-se pormenorizadamente todos os caracteres necessários para a sua identificação.
Os estudos fitoquímicos incluíram a caracterização do extracto por LC/UV/ES-MS com o consequente conhecimento do seu perfil químico. Identificaram-se como constituintes maioritários: terpenos, ácidos fenólicos, linhanos e taninos gálhicos.
Identificaram-se dois dos compostos fenólicos maioritários (ácido 3-cafeoilquínico e ácido 4,5-dicafeoilquínico), e o triterpeno β-sitosterol.
O extracto estudado mostrou ser activo contra estirpes de referência de Candida albicans, Enterococcus faecalis, Escherichia coli, Micrococcus luteus e Pseudomonas aeruginosa, e ser inactivo contra Staphylococcus aureus, no intervalo de concentrações testado. Este extracto mostrou também possuir actividade antioxidante relacionável com os compostos fenólicos maioritários identificados.
Os resultados da avaliação da toxicidade aguda em murganho mostraram não ser, este extracto, tóxico à concentração máxima de 1500 mg/Kg.
Calycobolus heudelotii (Baker ex Oliv.) Heine is a liana belonging to the Convolvulaceae family used in Guinea-Bissau and other African countries’ traditional medicine. In Guinea-Bissau, the stem of the liana is used as decoction in the treatment of skin allergies, inflammations and infected wounds. This paper presents the results of morphological, chemical, biological and toxicological studies, in order to contribute to a better understanding of this African medicinal plant. The methodology incorporated the macroscopic and microscopic analysis of stems of C. heudelotii, the evaluation of acute toxicity and antimicrobial activity determination of the methanolic extract, as well as the screening of the main chemical constituents and its antioxidant activity. The botanical studies allowed characterizing the structure of this anomalous liana, showing in detail all the characters needed for its identification. The phytochemical studies included the characterization of the extract by LC/UV/ES-MS with the resulting knowledge of its chemical screening. We have characterized as major constituents: terpenes, phenolic acids, lignans and gallic tannins. We have identified two of the majority phenolic compounds (3-caffeoylquinic acid and 4,5-dicaffeoylquinic acid), and the triterpene β-sitosterol. The extract proved activity against reference strains of Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Micrococcus luteus but was inactive against Staphylococcus aureus, in the range of tested concentrations. This extract has also shown to possess antioxidant activity, relatable to the main phenolic compounds identified. The results of the evaluation of acute toxicity in mice proved that, this extract, is nontoxic at maximum concentration of 1500 mg/Kg.
Calycobolus heudelotii (Baker ex Oliv.) Heine is a liana belonging to the Convolvulaceae family used in Guinea-Bissau and other African countries’ traditional medicine. In Guinea-Bissau, the stem of the liana is used as decoction in the treatment of skin allergies, inflammations and infected wounds. This paper presents the results of morphological, chemical, biological and toxicological studies, in order to contribute to a better understanding of this African medicinal plant. The methodology incorporated the macroscopic and microscopic analysis of stems of C. heudelotii, the evaluation of acute toxicity and antimicrobial activity determination of the methanolic extract, as well as the screening of the main chemical constituents and its antioxidant activity. The botanical studies allowed characterizing the structure of this anomalous liana, showing in detail all the characters needed for its identification. The phytochemical studies included the characterization of the extract by LC/UV/ES-MS with the resulting knowledge of its chemical screening. We have characterized as major constituents: terpenes, phenolic acids, lignans and gallic tannins. We have identified two of the majority phenolic compounds (3-caffeoylquinic acid and 4,5-dicaffeoylquinic acid), and the triterpene β-sitosterol. The extract proved activity against reference strains of Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Micrococcus luteus but was inactive against Staphylococcus aureus, in the range of tested concentrations. This extract has also shown to possess antioxidant activity, relatable to the main phenolic compounds identified. The results of the evaluation of acute toxicity in mice proved that, this extract, is nontoxic at maximum concentration of 1500 mg/Kg.
Descrição
Tese de mestrado, Medicamentos à Base de Plantas, Universidade de Lisboa, Faculdade de Farmácia, 2010
Palavras-chave
Teses de mestrado