Estudo estrutural e farmacognóstico de Scutellaria agrestis A. St.-Hil. ex Benth. (Lamiaceae): uma planta medicinal utilizada por populações ribeirinhas do Amazonas
Scutellaria agrestis (trevo-roxo) is a plant widely used by the riverine population of the Amazon state in the treatment of earaches, fever, diarrhea and high blood pressure. This work aimed to perform anatomical, histochemical, pharmacological and phytochemical analysis of the vegetative organs...
| Autor principal: | Oliveira, Andréia Barroncas de |
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| Grau: | Tese |
| Idioma: | por |
| Publicado em: |
Instituto Nacional de Pesquisas da Amazônia - INPA
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/12846 http://lattes.cnpq.br/6485986169802039 |
| Resumo: |
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Scutellaria agrestis (trevo-roxo) is a plant widely used by the riverine population
of the Amazon state in the treatment of earaches, fever, diarrhea and high blood pressure. This
work aimed to perform anatomical, histochemical, pharmacological and phytochemical
analysis of the vegetative organs of S. agrestis, in order to investigate the active principle of
this plant. Individuals of S. agrestis were collected in two locations, the first of them being the
riverine communities Nossa Senhora das Graças and Nossa Senhora de Nazaré, located in the
Solimões river, in Manacapuru, state of Amazonas, and the second one, the medicinal garden
of Nilton Lins University, in Manaus, Amazonas state. Samples of vegetative organs were
processed according to usual techniques of light microscopy and scanning electron
microscopy for anatomical study of the plant and ontogenetic study of plant trichomes. The
metabolites synthesized by secretory structures were detected and histolocalized by
phytochemical and histochemical tests. An aqueous extract was prepared from the leaf of the
studied species and experiments were performed to investigate the acute toxicity in vivo and
in vitro, and the analgesic and/or anti-inflammatory actions in vivo. Numerous glandular
trichomes are seen in both leaf and stem of S. agrestis. The epidermis of the vegetative organs
of this plant contains anthocyanins in the vacuole, except for the adaxial leaf epidermis. The
leaf is amphihypostomatic, with diacitic stomata. The leaf blade has uniseriate epidermis,
dorsiventral mesophyll and hydathodes are present along the margin. The midrib has a plan-
convex shape, with vascular tissue arranged in an open arc. The petiole has a concave-convex
shape, collateral vascular system. The stem is square-shaped with prominent vertices, evident
endoderm, collateral vascular system and parenchymatous pith. The root is protostelic, with
endoderm highlighted by suberified Casparian strips; cells of exodermis, cortex and
endodermis have mucilage and phenolic content. The ontogeny of trichomes of S. agrestis
follows the pattern for the family. The secretory structures responsible for the synthesis of
substances are peltate and capitate glands and the secretory epidermis. Such structures are the
site of secretion of the active principle of the plant, producing phenols (phenols, hydrolysable
tannins, coumarins and several classes of flavonoids such as anthocyanins, anthocyanidines,
chalcones, aurones, flavones, flavonols, xanthones, leucoanthocyanidines, flavanones,
flavanonols), terpenes (essential oils, free steroids, saponins), total lipids, proteins and acids.
The aqueous extract of S. agrestis leaf showed analgesic and anti-inflammatory response to the pain signal, but does not present antiedematogenic activity and has no toxic components,
so it is a vegetal drug with scientific support, giving a toxicological margin of safety for the
improvement of studies with this species. The results of this research provide botanical and
pharmacognostic data, contributing to the knowledge of this plant biology.
Keywords: trevo-roxo, ontogeny of secretory structures, histochemistry, phytochemistry,
biological assays. |