Hypolipidemic effects of Solidago chilensis hydroalcoholic extract and its major isolated constituent quercetrin in cholesterol-fed rats.

CONTEXT: Despite several studies on the effects of Solidago chilensis Meyen (Asteraceae), the phytochemical and hypolipidemic properties remain underappreciated. OBJECTIVE: This study evaluates the hypolipidemic and antioxidant effects of hydroalcoholic extract (HE) and quercetrin from S. chilensis aerial parts in cholesterol-fed rats. MATERIALS AND METHODS: The HE was analyzed by high-performance liquid chromatography, followed by quercetrin isolation. Hypercholesterolemic rats (1% cholesterol and 0.5% cholic acid for 15 d) were treated with HE (150, 300, and 600 mg/kg p.o.; n = 6), simvastatin (4 mg/kg p.o.; n = 6), or quercetrin (10 mg/kg p.o.; n = 6) once a day for 30 d. During this period, a high-cholesterol diet was maintained until the 30th day of treatment. RESULTS: Rats treated with HE (150, 300, and 600 mg/kg) and quercetrin showed decreased serum levels of total cholesterol (-19.9, -27.5, -31.0, and -39.4%), lipoprotein-cholesterol (-36.0, -37.5, -43.3, and -59.4%), and triacylglycerides (-15.6, -23.5, -29.8, and -27.2%) when compared with the control group similar to simvastatin. Moreover, treatment with HE and quercetrin decreased hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity (35.1% on average) and increased fecal cholesterol levels (38.2% on average). DISCUSSION AND CONCLUSIONS: Our results suggest that hypolipidemic effects of HE are associated with it modulating the activity of HMG-CoA reductase and its interference in the reabsorption and/or excretion of intestinal lipids. Solidago chilensis and its main constituent, quercetrin, may thus be effective as cholesterol-lowering agents and in preventing atherosclerosis.

Himatanthus lancifolius (Müll. Arg.) Woodson, Apocynaceae: estudo farmacobotânico de uma planta medicinal da Farmacopeia brasileira 1ª edição / Himatanthus lancifolius (Müll. Arg.) Woodson, Apocynaceae: morpho-anatomical study of a medicinal plant described in the Brazilian Pharmacopoeia 1st edition

Himatanthus lancifolius (Müll. Arg.) Woodson é um arbusto nativo do Brasil, latescente, popularmente conhecido como agoniada e utilizado principalmente para distúrbios menstruais. O presente trabalho teve como objetivo caracterizar morfoanatomicamente a folha, o caule e a casca caulinar dessa planta medicinal, a fim de contribuir para o controle de qualidade e a autenticidade dessa espécie. O material vegetal foi fixado e submetido às microtécnicas usuais. A folha é simples, glabra e obovado-lanceolada. A epiderme é uniestratificada, revestida por cutícula estriada e possui estômatos anisocíticos na face abaxial. O mesofilo é dorsiventral. A nervura central é biconvexa e o pecíolo é circular, ambos apresentando feixes vasculares bicolaterais. Laticíferos, amiloplastos e idioblastos fenólicos estão presentes no parênquima fundamental da nervura central e do pecíolo. O sistema vascular do caule é tipicamente bicolateral. Laticíferos e idioblastos fenólicos ocorrem no córtex, no floema e na medula. Esses caracteres morfoanatômicos, em conjunto, podem ser utilizados como parâmetros para o controle de qualidade dessa espécie.

Himatanthus lancifolius (Müll. Arg.) Woodson is a Brazilian native shrub, laticiferous, popularly known as "agoniada" and it is mainly used for uterine disorders. The present work aimed to study the leaf, stem and stem bark morpho-anatomy of this medicinal plant, in order to contribute to its quality control and identification. The plant material was fixed and submitted to standard microtechniques. The leaf is simple, glabrous and obovate-lanceolate. The epidermis is uniseriate, coated with striated cuticle and it has anysocitic stomata on the abaxial surface. The mesophyll is dorsiventral. The midrib is biconvex and the petiole is circular, both presenting bicollateral vascular bundles. Laticiferous ducts, amyloplasts and phenolic idioblasts are found in ground parenchyma of the midrib and petiole. The vascular system of the stem is tipically bicollateral. Laticiferous ducts and phenolic idioblasts are present in the cortex, phloem and pith. These morpho-anatomical characters, all together, can be used as quality control parameters of this species.

Acetylcholinesterase inhibitory activity of uleine from Himatanthus lancifolius.

Application of acetylcholinesterase (AChE) inhibitors is the primary treatment for Alzheimer's disease. Alkaloids, such as physostigmine, galanthamine, and huperzine A, play an important role as AChE inhibitors. The aim of this work was to evaluate Himatanthus lancifolius (Muell. Arg.) Woodson, a Brazilian species of Apocynaceae, and its main indole alkaloid uleine, in order to identify new AChE inhibitors. The plant fluid extract, fractions, and uleine were tested for AChE inhibitory activity using Ellman's colorimetric method for thin-layer chromatography (TLC), 96-well microplates, and also Marston's TLC colorimetric method. Both TLC assays showed similar results. At 5 mg/mL, the fluid extract inhibited the AChE enzyme by (50.71 +/- 8.2)%. The ethyl acetate fraction exhibited the highest level of AChE inhibition, followed by the dichloromethane fraction. The isolated alkaloid uleine displayed an IC50 value of 0.45 microM.

Human erythrocytes as a system for evaluating the antioxidant capacity of vegetable extracts.

Free radicals are fairly unstable and highly reactive substances, able of causing oxidation and sometimes-irreversible damage to cells, compromising their function. The Brassicaceae family has many important species for the regular human diet as they provide several antioxidant constituents. In this study, the antioxidant potential of the hydroethanolic extracts prepared from the edible parts of kale, broccoli, and radish was investigated in vitro using human erythrocytes under oxidative stress imposed by phenylhydrazine as an experimental model, in which the methemoglobin levels were measured. When the results were compared with the antioxidant capacity shown by the traditional 2,2-diphenyl-2-picrylhydrazyl hydrate free radical and phosphomolybdenum complex methods, the extracts tested showed significant and correspondent antioxidant activity. Broccoli extract presented the highest antioxidant activity, followed closely by the kale, whereas the radish extract occupied the lowest position. The results derived from the human erythrocyte system have shown it as an alternative method for evaluating the antioxidant properties of vegetable extracts.

Ação da uleína sobre a produção de óxido nítrico em células RAEC e B16F10 / Uleine effect on the production of nitric oxide in RAEC and B16F10 cells

Foi investigada a influência da fração rica em alcalóides e da substância majoritária desta fração, uleína, isolada das cascas de Himatanthus lancifolius (Muell. Arg.) Woodson, Apocynaceae, popularmente conhecida como agoniada, sobre a produção de óxido nítrico em células RAEC e B16F10 e a correlação com a atividade antioxidante. Os ensaios de atividade antioxidante foram realizados utilizando os métodos de redução do complexo fosfomolibdênico e o da redução do radical livre DPPH. Os resultados demonstraram uma atividade antioxidante de 59,3 ± 0,8 por cento para a fração alcaloídica, enquanto que, para a uleína, esse efeito foi de 0,5 ± 0,1 por cento no ensaio de redução do complexo fosfomolibdênico. No ensaio do DPPH, a fração alcaloídica apresentou IC50 = 196,3 ± 8,9 µg/mL e para a uleína 6475,0 ± 25,0 µg/mL. A uleína, principal alcalóide da fração, estimulou uma produção máxima de óxido nítrico nas concentrações de 0,1 µg/ml (20,9 ± 1,4 µM) e 1 µg/ml (41,1 ± 0,2 µM) utilizando células RAEC e B16F10, respectivamente, demonstrando que o efeito da uleína nas células ocorre através de estímulos nas vias de produção de óxido nítrico e não por um efeito sequestrante de radical livre.

The influence of the rich alkaloidal fraction and of the major substance in this fraction, uleine, isolated from the barks of Himatanthus lancifolius (Muell. Arg.) Woodson, Apocynaceae, popularly known as agoniada, on the nitric oxide production in RAEC and B16F10 cells and its correlation with the antioxidant activity, were investigated. For the antioxidant activity the methods of formation of a phosphomolybdenum complex and the reduction of the free radical DPPH were used. The results demonstrated an antioxidant activity of 59.3 ± 0.8 percent for the alkaloidal fraction, while for uleine the effect was of 0.5 ± 0.1 percent in the reduction of the phosphomolibdenium method. In the assay of DPPH, the alkaloidal fraction presented IC50 = 196.3 ± 8.9 µg/mL and for uleine, 6475.0 ± 25.0 µg/mL. Uleine also stimulated a maximum nitric oxide production in the concentrations of 0.1 µg/mL (20.9 ± 1.4 µM) and 1 µg/mL (41.1 ± 0.2 µM) using RAEC and B16F10 cells, respectively, demonstrating that the effect of uleine in the cells occurs by promoting the nitric oxide production pathway, but not through a free radical scavenger effect.

A citometria de fluxo como instrumento de avaliação da atividade imunomodulatória de extratos e substâncias isoladas de plantas medicinais / Flow cytometry as instrument for evaluating the immunopotential of medicinal plant extracts and their isolated compounds

A citometria de fluxo vem se consolidando como metodologia para vários estudos de atividade celular e, nesse trabalho, ela foi empregada para avaliar as ações da fitohemaglutinina, dos alcalóides vimblastina e vindolina e dos extratos de Chamomilla recutita (L.) Rauschert, Bauhinia microstachya (Raddi) Machr. e Himatanthus lancifolius (Muell. Arg.) Woodson, conhecidos popularmente no Brasil como camomila, escada-de-macaco e agoniada, respectivamente, sobre a imunomodulação de células mononucleares humanas, comparando-se o desempenho obtido com as alterações morfológicas relacionadas à ativação e proliferação dessas células in vitro. Os resultados demonstram que foi possível identificar, pela metodologia proposta, os efeitos proliferativos estimulantes já descritos para a fitohemaglutinina e para o extrato de C. recutita, assim como para o extrato de B. microstachya, observado pela primeira vez nesse trabalho. A conhecida atividade inibitória da vimblastina sobre a proliferação de linfócitos induzida por fitohemaglutinina, em contraste como a ausência de efeitos da vindolina, também puderam ser evidenciadas. Efeito inibitório foi observado para o extrato de H. lancifolius devido à sua ação tóxica sobre o sistema. Os resultados apresentados sugerem que a citometria de fluxo pode ser usada como uma alternativa metodológica quando se deseja investigar a ação de substâncias puras ou de extratos de plantas sobre a imunomodulação de células mononucleares humanas.

Flow cytometry has been widely applied for studying several cellular activities. In this work it has been used to evaluate the effects of phytohemagglutinin, vinblastine, and vindoline upon human mononuclear cells immunomodulation. The same protocol was used to investigate the effects of extracts prepared from Chamomilla recutita (L.) Rauschert, Bauhinia microstachya (Raddi) Machr., and Himatanthus lancifolius (Muell. Arg.) Woodson, plants popularly known in Brazil as camomila, escada-de-macaco, and agoniada, respectively. The activity was then compared with the in vitro cellular morphological changes. By the results herein presented, the proposed method allowed the identification of the already known phytohemagglutinin and C. recutita extract proliferative effects, as well as for the B. microstachya extract, reported for the first time. The inhibition of vinblastine upon the proliferation of phytohemagglutin-stimulated cells and the lack of effects of vindoline were also evident. Exposition to H. lancifolius extract has led to inhibition of lymphocyte proliferation as a result of the high toxicity of the extract upon the system. Results presented strongly suggest flow cytometry as a useful instrument to evaluatethe immunomodulation effects of pure compounds or complex mixtures such as plant extracts upon human mononuclear cells.

Effects of alkaloids of Himatanthus lancifolius (Muell. Arg.) Woodson, Apocynaceae, on smooth muscle responsiveness.

Himatanthus lancifolius, popularly known as "agoniada" in Brazil, is largely used in folk medicine against asthma, dysmenorrhea and as an emenagogue and abortive. This study reveals the effects of an alkaloid rich fraction (AlkF) obtained from the bark of Himatanthus lancifolius in vascular and non-vascular smooth muscle responsiveness. Incubation of AlkF (3-30 microg/ml) during 15 min generates a concentration-related and fully reversible reduction in maximal contractile responses evoked by acetylcholine and phenylephrine in rat jejune and aorta preparations, respectively. Exposition of endothelium-denuded pre-contracted rat aorta rings to AlkF results in a complete relaxation, with EC(50) of 22.2 (16.2-28.2 microg/ml). AlkF is also able to induce a concentration-related rightward shift of cumulative concentration curves for calcium in uterus and aorta rings maintained in depolarizing nutritive solution. Moreover, addition of AlkF in calcium-free solution also reduces, in a concentration-dependent manner, the ability of caffeine and phenylephrine to contract aorta rings. This study reveals that the bark of Himatanthus lancifolius possesses one or more indole alkaloids able to alter non-vascular and vascular smooth muscle responsiveness, an event that may involve the blocking of calcium entry or changes on intracellular calcium utilization or mobilization.