Effect of Artemisia annua L. leaves essential oil and ethanol extract on behavioral assays

Artemisia annua tem sido utilizada tradicionalmente para o tratamento de malária e febre na China devido à presença do princípio ativo, artemisinina. O presente trabalho avaliou a atividade central de do óleo essencial obtido por hidrodestilação e do extrato etanólico bruto de folhas frescas de A. annua em modelo in vivo como parte de um screening farmacológico dessa espécie. Sono induzido por pentobarbital, nado forçado e o ensaio de campo aberto são modelos de estudo conhecidos para o estudo de fármacos sobre depressão induzida. A administração do óleo essencial ou extrato bruto etanólico de A. annua aumentaram o tempo de imobilidade no teste do nado forçado. Por outro lado, diminuíram outros parâmetros no campo aberto, como ambulação, exploração, o ato de lamber as patas ou se lamber. Ambos produtos aumentaram o tempo de sono induzido por pentobarbital, com o óleo essencial apresentando um efeito superior ao do extrato. Pela análise dos resultados, é possível sugerir que tanto o extrato bem como o óleo essencial podem atuar como depressores do Sistema Nervoso Central (SNC).

Studies of gastric mucosa regeneration and safety promoted by Mouriri pusa treatment in acetic acid ulcer model

Ethnopharmacological Relevance: Mouriri pusa Gardn. (Melastomataceae) is a medicinal plant commonly used by people living in the Cerrado to treat gastrointestinal disturbances. This medicinal plant has shown intense gastroprotective action in rodent gastric lesion, but still there are no data about its healing effect on gastric mucosa.Aim of the Study: To evaluate the methanolic extract (MeOH) obtained from Mouriri pusa leaves for its effect on the cicatrisation process of gastric ulcer.Mterials and Methods: The healing effects on gastric ulcers inducted by subserosal injection of acetic acid were evaluated by macroscopic and microscopic measures, imunohistochemistry and cell counting in rats treated with MeOH extract of Mouriri pusa (250 mg/kg, p.o./daily) for 14 or 30 days. The toxicity of Mouriri pusa was also evaluated by body and organ weight measure and clinical biochemical parameters.Results: Mouriri pusa treatments lasting 14 and 30 days showed elevated mucus secretion (PAS) and thicker regenerative gastric mucosa, denoting increased cell proliferation, which was confirmed by PCNA immunohistochemical analysis. Moreover, there was important cell recruitment (neutrophils and mast cells) to the site of the ulcer, which is an important factor in ulcer healing. No toxic effect was observed in all parameters evaluated. Phenolic compounds present in the MeOH extract like tannins, flavonoids and epicatechin are the probable agents involved in the healing effects of this medicinal plant.Conclusions: These findings showed a potential effect of Mouriri pusa in increasing regeneration of damaged gastric mucosa with safety for human use. (C) 2007 Elsevier B.V. All rights reserved.

Structural and ultrastructural aspects of ontogenesis and differentiation of resin secretory cavities in Hymenaea stigonocarpa (Fabaceae-Caesalpinioideae) leaves

Cell lysis in the formation of secretory cavities in plants has been questioned by some authors and considered as result of technical artifacts. To describe the formation of secretory resin cavities in Hymenaea stigonocarpa leaves, leaflet samples at different stages of differentiation were collected, fixed, and processed for light and electron microscopy as per usual methods. The initial cells of secretory resin cavities are protodermal and grow towards the mesophyll ground meristem; these cells then divide producing cell groups that are distinguished by the shape and arrangement of cytoplasm, and density. At the initial stages of differentiation of the secretory cavities, some central cells in these groups show dark cytoplasm and condensed nuclear chromatin. Later, there is cell wall loosening, tonoplast and plasmalemma rupture resulting in cell death. These cells, however, maintain organelle integrity until lysis, when the cell wall degrades and the plasmalemma ruptures, releasing protoplast residues, marked characteristics of programmed cell death. The secretory epithelium remains active until complete leaf expansion when the cavity is filled with resin and the secretory activity ceases. There are no wall residues between central cells in adult cavities. Our results demonstrate lysigeny and the importance of ontogenetic studies in determining the origin of secretory cavities.

Ultrastructure of the intercellular protuberances in leaves of Paepalanthus superbus Ruhl. (Eriocaulaceae)

Folhas adultas de Paepalanthus superbus mostram protuberâncias intercelulares, entre a parede periclinal interna das células epidérmicas e superfície de células parenquimáticas; depósitos semelhantes ocorrem na superfície das células parenquimáticas do mesofilo. Estas protuberâncias são mais proeminentes ao redor de células parenquimáticas, formando uma estrutura que lembra uma cápsula gelatinosa. Testes histoquímicos com vermelho de rutênio evidenciam sua natureza péctica, com inclusões lipídicas dispersas, detectadas por sudan IV e sudan black B. Ultra-estruturalmente as protuberâncias mostram matriz fibrilar permeada por estruturas fimbriadas e tubulares, com margem distinta formada por estrutura membranosa. Nossos resultados sugerem que estas protuberâncias são derivadas de atividade secretora, sendo formadas após o desenvolvimento dos espaços intercelulares. em P. superbus esta estrutura pode representar uma especialização da parede celular, relacionada com adesão e mecanismos de transporte entre células.

Can sieve-element plastids in Panicum maximum (Poaceae) leaves act in the blockage of injured sieve-tube elements?

The ultrastructural features and the plastid changes caused by sample preparation were studied in sieve elements of Panicum maximum leaves. Samples of expanded leaves, taken near the ligule region, were fixed and processed by common light and transmission electron microscopy methods. In mature sieve-tube elements, the protoplast is electron-translucent and plastids are the most frequent organelles. Mitochondria and smooth endoplasmic reticulum segments are also visible and occupy a parietal position within the cell. The plastids are globular and show electron-dense proteinaceous inclusions in the stroma. The protein crystals are predominantly cuneate, but thin crystalloids and amorphous and/or filamentous proteins also occur. The presence of intact plastids plus others in different phases of plastid envelope rupture were interpreted as evidence that this rupture is a normal event in response to injury. This plastid envelope rupture is possibly activated by the release of pressure in the sieve-tube element. After plastid membrane vesiculation, the stroma and the protein crystals are dispersed within the sieve-element ground cytoplasm. The vesicles originating from the plastid envelope move to one cell pole, while protein crystalloids move to the opposite pole and agglomerate in the sieve-plate region. Our findings indicate that these protein crystalloids, which deposit in the sieve plate, may act in sieve-plate pores occlusion, preventing the release of phloem sap, similar to the role of P-protein in dicotyledons. (c) 2008 Elsevier GmbH. All rights reserved.

In Vitro Phytotoxicity and Antioxidant Activity of Selected Flavonoids

The knowledge of flavonoids involved in plant-plant interactions and their mechanisms of action are poor and, moreover, the structural characteristics required for these biological activities are scarcely known. The objective of this work was to study the possible in vitro phytotoxic effects of 27 flavonoids on the germination and early radical growth of Raphanus sativus L. and Lepidium sativum L., with the aim to evaluate the possible structure/activity relationship. Moreover, the antioxidant activity of the same compounds was also evaluated. Generally, in response to various tested flavonoids, germination was only slightly affected, whereas significant differences were observed in the activity of the various tested flavonoids against radical elongation. DPPH test confirms the antioxidant activity of luteolin, quercetin, catechol, morin, and catechin. The biological activity recorded is discussed in relation to the structure of compounds and their capability to interact with cell structures and physiology. No correlation was found between phytotoxic and antioxidant activities.

Studies on anti-allergic constituents in the leaves and stems of Anchietia salutaris var. martiana (Violaceae)

The anti-allergic active fractionation of hexane extracts of the leaves and stems of Anchietia salutaris,ar. martiana (family Violaceae) nas performed by monitoring their activities with an in vitro bioassay system measuring the inhibitory effects on induced histamine release from guinea pig lung cells. Three known pentacyclic triterpenes (friedelin, alpha-amyrin, beta-amyrin) were isolated, but these compounds were inactive. Aliphatic hydrocarbons and methyl esters of fatty acids (palmitic, oleic, linoleic, linolenic acids) were detected in active fractions. All compounds isolated were detected for the first time in this medicinal plant.

Gastric anti-ulcer activity of leaf fractions obtained of polar extract from Wilbrandia ebracteata in mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Byrsonima intermedia A. Juss.: Gastric and duodenal anti-ulcer, antimicrobial and antidiarrheal effects in experimental rodent models

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antiulcerogenic activity of Alchornea castaneaefolia: Effects on sornatostatin, gastrin and prostaglandin

The hydroethanolic extract of the leaves (HEL) and bark (HEB) obtained from Alchornea castaneaefolia (Euphorbiaceae) were investigated for their ability to prevent ulceration of the gastric mucosa in animal models. HEL (500 and 1000 mg/kg) and HEB (1000 mg/kg) significantly reduced the gastric injuries induced by the combination of HCl/ethanol and lowered the severity of gastric damage formation induced by indomethacin/bethanechol in mice. Further investigation showed that HEL also inhibited formation of ulcers in mice submitted to stress and pylorus ligature, but HEL did not modify gastric juice parameters in Shay mice. HEL was also effective in promoting the healing process in chronic gastric ulcer induced by acetic acid in rats. An enriched flavonoidic fraction (EFF at dose of 100 mg/kg) obtained from HEL reduced gastric lesions induced by HCl/ethanol and indomethacin/bethanechol in mice. Although EFF did not modify the amount of free mucus production by gastric mucosa, it was able to increase prostaglandin production. When administered to rats submitted to ethanol-induced gastric lesions, EFF increased the somatostatin serum levels, while the gastrin serum levels were proportionally decreased. Phytochemical investigation on HEL and EFF led to the isolation of flavonoids glycosides as the main compounds, thus suggesting that these substances may be involved in the observed antiulcer activity. (c) 2005 Elsevier B.V.. All rights reserved.

Polyphenols with Antiulcerogenic Action from Aqueous Decoction of Mango Leaves (Mangifera indica L.)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anti-hemorrhagic Activity of Four Brazilian Vegetable Species Against Bothrops jararaca Venom

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The promoter of a gene encoding an isoflavone reductase-like protein in coffee (Coffea arabica) drives a stress-responsive expression in leaves

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chemical investigation and effects of the tea of Passiflora alata on biochemical parameters in rats

Passiflora alata (Passifloraceae) is a native plant from the South-America tropical forest that provides a much apreciated fruit known as maracuja-doce. Although tea of the leaves of Passiflora alata is used in folk medicine as a sedative and tranquilizer, there are no investigations about its effects on biochemical parameters in blood or from its major chemical composition. The purpose of this study was to evaluate the effects of the tea of the leaves of Passiflora alata on biochemical parameters (antioxidant system, glucose and cholesterol levels) and to perform a phytochemical investigation of the tea. We isolated and identified two saponins and five C-glycosylflavones derived from apigenin, luteolin and chrysoeriol. Three of them are new in this species. Passiflora alata extract was administrated orally in rats at dose of 1000 mg/kg and it was observed an increase in high-density lipoprotein level (HDL-cholesterol). (C) 2004 Elsevier B.V.. All rights reserved.