RESUMO

Kaurenoic acid (KA) is a diterpene extracted from Sphagneticola trilobata (L.) Pruski. KA presents analgesic properties. However, the analgesic activity and mechanisms of action of KA in neuropathic pain have not been investigated so far; thus, we addressed these points in the present study. A mouse model of neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve. Acute (at the 7th-day post-CCI surgery) and prolonged (from 7-14th days post-CCI surgery) KA post-treatment inhibited CCI-induced mechanical hyperalgesia at all evaluated time points, as per the electronic version of von Frey filaments. The underlying mechanism of KA was dependent on activating the NO/cGMP/PKG/ATP-sensitive potassium channel signaling pathway since L-NAME, ODQ, KT5823, and glibenclamide abolished KA analgesia. KA reduced the activation of primary afferent sensory neurons, as observed by a reduction in CCI-triggered colocalization of pNF-κB and NeuN in DRG neurons. KA treatment also increased the expression of neuronal nitric oxide synthase (nNOS) at the protein level as well as the intracellular levels of NO in DRG neurons. Therefore, our results provide evidence that KA inhibits CCI neuropathic pain by activating a neuronal analgesic mechanism that depends on nNOS production of NO to silence the nociceptive signaling that generates analgesia.

RESUMO

O interesse de pesquisadores e da população geral é bastante evidente, e tem crescido bastante na atualidade, no uso de plantas medicinais. A espécie de interesse deste trabalho, a Sphagneticola trilobata Pruski é uma planta herbácea pertencente à família Asteraceae. Alguns relatos têm mostrado a presença de diversos constituintes químicos nesta planta, principalmente diterpenos. O presente trabalho realizou o estudo fitoquímico de uma fração do extrato hexânico, devido ao baixo rendimento da fração diclorometânica, através da utilização de diversos métodos cromatográficos, na qual isolouse o fitoesterol estigmasterol. Este composto foi confirmado por meio de dados espectroscópicos e de literaturas, e o isolamento de compostos desta classe de substâncias indicam uma nova vertente para o uso medicinal desta planta como um futuro hipocolesterolêmico. Para isto, estudos serão direcionados para o isolamento de fitoesteróis, com posterior realização de ensaios biológicos (AU)

The interest of researchers and the general population is quite evident, and has grown considerably today, in the use of medicinal plants. The species of interest in this work, Sphagneticola trilobata Pruski is a herbaceous plant, belonging to Asteraceae family. Some reports have shown the presence of several chemical constituents in this plant, mainly diterpenes. The present work carried out the phytochemical study of a fraction of the hexane extract, due to the low yield of the dichloromethane fraction, by several chromatographic methods, in which the phytosterol estigmasterol was isolated. This compound has been confirmed by means of spectroscopic and literature data, and the isolation of compounds of this class of substances indicates a new strand for the medicinal use of this plant as a hypocholesterolemic future. For this, studies will be directed to the isolation of phytosterols, with subsequent biological tests (AU)

Assuntos

RESUMO

As the temperature of extraction and processing could impact the biological effects of herbal extracts, which have wide chemical diversity, the aim of this work were to investigate the thermostability of herbal derivatives of the aerial parts of Sphagneticola trilobata, a reputed medicinal plant; to biomonitor its oral anti-hyperalgesic effect; and to elucidate the degradation pathways of the major components by UHPLC-ESI-QTOF-MS. The lipophilic markers (kaurenoic acid-KA) and hydrophilic markers [chlorogenic acids; measured as total phenolic compounds (PC), expressed in caffeic acid] were also monitored through a validated HPLC-UV methodology, suitable for quality control and stability studies. The soft extract (drug:solvent ratio of 1:10, ethanol 60% v/v) was exposed to high temperatures (50-180°C). PC showed high thermolability (27.4% of degradation at 150°C), compared to KA (16.5%, at 180°C). These results suggest that the loss of oral anti-hyperalgesic activity observed in the spray-dried extracts (dried at 170°C), compared with the soft and the lyophilized extract may be related to degradation of the active components, especially the polar compounds, i.e. chlorogenic acid derivatives and the four oleanane type triterpenoid saponins. These latter degraded at temperatures above 150°C and vanished at 180°C, as demonstrated in the UHPLC-ESI-QTOF-MS analyses. These results provide a relevant guide for the extraction process of S. trilobata, aimed at preserving the antinociceptive effect.

Assuntos

RESUMO

Anatomical and histochemical investigations of Sphagneticola trilobata (L.) Pruski, Asteraceae, secretory structures in leaves and stems and the seasonal variation of essential oils were carried out. Histochemical techniques enabled the specific location of the essential oil accumulation in the internal (canals) and external structures (trichomes). Histochemical analysis showed that the secretory trichomes produced steroids. The highest yield was obtained from plants collected in winter, when it was registered low temperature and precipitation. The essential oil was characterized by high percentage of hydrocarbon sesquiterpenes, hydrocarbon monoterpenes and low levels of oxygenated sesquiterpenes. The major components were germacrene D (11.9-35.8%), α-phellandrene (1.4-28.5%), α-pinene (7.3-23.8%), E-caryophyllene (4.6-19.0%), bicyclogermacrene (6.0-17.0%), limonene (1.8-15.1%) and α-humulene (4.0-11.6%). The percentage of most of the individual constituents present in S. trilobata essential oil changed significantly during the months.

RESUMO

O presente trabalho teve por objetivo o estabelecimento de parâmetros para análise morfo-anatômica das partes aéreas (caule e folhas) da planta Wedelia paludosa DC., Asteraceae. A droga vegetal e o respectivo pó foram submetidos às análises macro e microscópica após preparação de lâminas semi-permanentes de cortes transversais e paradérmicos. O pó foi analisado após diafanização com cloral hidratado. É uma planta herbácea com caule castanho-avermelhado, folhas opostas, curto-pecioladas e membranáceas, apresentando pêlos nas duas faces, estreitada em direção à base acima do meio provida de dois pequenos lobos laterais e um terminal, maior e denteado. A planta apresenta secção circular de caule, que em crescimento primário, possui epiderme, colênquima angular, parênquima cortical e cilindro vascular, assim como oxalato de cálcio (várias drusas e alguns cristais prismáticos). A folha é simples, contendo tricomas tectores e estômato anomocítico. O mesofilo possui organização dorso-ventral e a nervura central, em corte transversal, apresenta-se côncavo-convexo com três feixes colaterais e presença de drusas de oxalato de cálcio nas células parenquimáticas. No pó obtido da droga vegetal foram verificadas as mesmas estruturas microscópicas observadas na droga vegetal rasurada. Os parâmetros morfo-anatômicos estabelecidos neste trabalho permitem o controle de qualidade macro e microscópico da planta tanto rasurada como na forma de pó.

This study aimed to establish parameters for morphoanatomical analysis of the aerial parts (stem and leaves) of the plant Wedelia paludosa DC., Asteraceae. The drug and its respective powder were characterized by macro and microscopic analysis after obtaining semi-permanent lamina of transverse and paradermal sections. The powder was analyzed after being cleared with chloral hydrate. It is an herbaceous plant with reddish-brown stems, opposite leaves, short-petiolated and membranous, with hair on both faces, narrowed towards the base up the middle provided with two small lateral lobes and a, large and jagged terminal. The plant has circular cross-section of stem, in which the primary growth, has epidermis, angular collenchyma, cortical parenchyma and vascular cylinder, as well as calcium oxalate (several clusters and some prismatic crystals). The leaf is simple, containing trichomes and stomata. The mesophyll has dorsiventral organization and the midrib, in cross section presents concave-convex face with three bundles and presence of calcium oxalate in parenchymal cells. In the powder was found the same structures observed in microscopic drug erased. The morphoanatomical parameters established in this work allow the macro and microscopic quality control of power and sectioned drug.