Antiulcerogenic activity of four extracts obtained from the bark wood of Quassia amara L. (Simaroubaceae)

Quassia amara L., a neotropical forest shrub of the Simaroubaceae family, is widely used in Caribbean folk medicine and in some northern states of Brazil for the treatment of gastric ulcers. This plant is a source of numerous compounds including both beta-carbonile and cantin-6 alkaloids as well as, primarily, the bitter compounds known as quassinoids. We analyzed the possible antiulcerogenic activities of four extracts of different polarities: 70% ethanol (70% EtOH), 100% EtOH, 100% dichloromethane (DCM), and 100% hexane (HEX) obtained from Quassia amara bark. All extracts, administered at doses of 5000 mg/kg orally and 1000 mg/kg intraperitoneally, caused neither toxicity or death. In the indomethacin[bethanechol-induced gastric ulcer, 70% EtOH, 100% EtOH, DCM and HEX extracts, 100 mg/kg, p.o., inhibited the gastric ulcer (22.5, 23.4, 50.5, 46.8%, respectively). 70% EtOH, 100% EtOH, DCM, and HEX extracts reduced the gastric injury induced by the hypothermic restraint-stress test in mice (70.7, 80, 60, 82.7%, respectively). In the pylorus ligature of the mouse stomach, following pre-treatment with a single intraduodenal administration of 100 mg/kg of each extract, only 70% EtOH did not change the biochemical parameters of gastric juice. 100% EtOH, DCM and HEX extracts presented decreased gastric juice content, increased pH values and decreased acid output. We also determined the antiulcerogenic activity on HCl-EtOH-induced gastric ulcers in mice at four doses (25, 50, 75, 100 mg/kg, p.o.), then evaluated the possible dose-dependent relation and calculated the ED50 values. Except for 70% EtOH at a dose of 25 mg/kg, the other extracts showed significantly activity (p<0.05). The free mucous amount in the gastric stomach content was also evaluated. All extracts showed significant increases (p<0.05) of free mucous. This effect was abolished when the animals were pre-treated with indomethacin. Prostaglandin synthesis was evaluated by the administration of HEX extracts by the oral route (100 mg/kg). Prostaglandin synthesis was significantly, increased by 52.3% (p<0.05), and this effect was abolished with prior administration of indomethacin. We concluded that Quassia amara is a probable source for a new drug to treat gastric ulcers, and the mechanism of its activity relates to cytoprotective factors, such as mucous and prostaglandins, but there is still the possibility that antisecretory activity is involved in its antiulcerogenic effect.

Flavonoids and antiulcerogenic activity from Byrsonima crassa leaves extracts

Byrsonima crassa Niedenzu (IK) (Malpighiaceae) is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric ulcers. In this study, we evaluated the potential antiulcerogenic effect of three different extracts obtained from the leaves of Byrsonima crassa namely hydromethanolic (80% MeOH), methanolic (MeOH) and chloroformic extracts (CHCl3). The oral administration (250, 500 and 1000 mg/kg) of all the extracts reduced the formation of lesions associated with HCl/ethanol administration in mice. The 80% MeOH extract significantly reduced the incidence of gastric lesions by 74, 78 and 92% at doses of 250,500 and 1000 mg/kg, respectively (P < 0.01). The MeOH extract reduced the ulceration by 93 and 99% only at the doses of 500 and 1000 mg/kg (P < 0.01). The lower gastroprotective action (69%) was observed when animals were treated with CHCl3 extract at the dose of 1000 mg/kg (P < 0.01). Phytochemical investigation of Byrsonima crassa afforded five known substances: quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, the biflavonoid amentoflavone, (+)-catechin and (-)-epicatechin. The presence of these phenolic compounds may probably explain the antiulcerogenic effect of the extracts of Byrsonima crassa leaves. (C) 2004 Elsevier B.V.. All rights reserved.

The gastroprotective effect of the essential oil of Croton cajucara is different in normal rats than in malnourished rats

It has been shown previously that malnourished rats are resistant to acute gastric lesions but not to subchronic gastric ulceration. It also has been demonstrated that the essential oil obtained from the bark of Croton cajucara (Sacaca) has antiulcer properties. In the present study, the ability of this essential oil to prevent the formation of gastric ulcers in rats fed a diet with 17 % protein (normoproteic rats) or 6 % protein (malnourished rats) was investigated. At a dose of 100 mg/kg body weight, orally, the essential oil significantly reduced the gastric injury caused by indomethacin (25 % after 2 h and 70 % after 4 h) only in normoproteic rats. In the pylorus ligature model, the essential oil increased the pH and gastric volume, but decreased the total acid concentration in both groups when compared to the respective control group. The essential oil significantly increased prostaglandin E2 production in glandular cells by 50 % compared to the controls in both groups of rats. In addition, the amount of gastric mucus was two-fold higher in malnourished rats than in normoproteic rats. The present results show that the enhanced protective effect of essential oil in malnourished rats involved an increase in prostaglandin E2 production and mucus secretion, which are both factors that protect the gastric mucosa against damage. In agreement with this, malnourished rats always had a lower number of acute gastric ulcers.

Healing, Antioxidant and Cytoprotective Properties of Indigofera truxillensis in Different Models of Gastric Ulcer in Rats

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

The 20S proteasome alpha(5) subunit of Arabidopsis thaliana carries an RNase activity and interacts in planta with the Lettuce mosaic potyvirus HcPro protein

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

SIRT1 Deacetylase Activity and the Maintenance of Protein Homeostasis in Response to Stress: An Overview

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

Identification of suitable internal control genes for expression studies in Coffea arabica under different experimental conditions

Background: Quantitative data from gene expression experiments are often normalized by transcription levels of reference or housekeeping genes. An inherent assumption for their use is that the expression of these genes is highly uniform in living organisms during various phases of development, in different cell types and under diverse environmental conditions. To date, the validation of reference genes in plants has received very little attention and suitable reference genes have not been defined for a great number of crop species including Coffea arabica. The aim of the research reported herein was to compare the relative expression of a set of potential reference genes across different types of tissue/organ samples of coffee. We also validated the expression profiles of the selected reference genes at various stages of development and under a specific biotic stress.Results: The expression levels of five frequently used housekeeping genes (reference genes), namely alcohol dehydrogenase (adh), 14-3-3, polyubiquitin (poly), beta-actin (actin) and glyceraldehyde-3-phosphate dehydrogenase (gapdh) was assessed by quantitative real-time RT-PCR over a set of five tissue/organ samples (root, stem, leaf, flower, and fruits) of Coffea arabica plants. In addition to these commonly used internal controls, three other genes encoding a cysteine proteinase (cys), a caffeine synthase (ccs) and the 60S ribosomal protein L7 (rpl7) were also tested. Their stability and suitability as reference genes were validated by geNorm, NormFinder and BestKeeper programs. The obtained results revealed significantly variable expression levels of all reference genes analyzed, with the exception of gapdh, which showed no significant changes in expression among the investigated experimental conditions.Conclusion: Our data suggests that the expression of housekeeping genes is not completely stable in coffee. Based on our results, gapdh, followed by 14-3-3 and rpl7 were found to be homogeneously expressed and are therefore adequate for normalization purposes, showing equivalent transcript levels in different tissue/ organ samples. Gapdh is therefore the recommended reference gene for measuring gene expression in Coffea arabica. Its use will enable more accurate and reliable normalization of tissue/organ-specific gene expression studies in this important cherry crop plant.

Effects of propolis from Brazil and Bulgaria on fungicidal activity of macrophages against Paracoccidioides brasiliensis

Paracoccidioidomycosis is the most important systemic mycosis in Latin America. Its etiological agent, Paracoccidoides brasiliensis, affects individuals living in endemic areas through inhalation of airborne conidia or mycelial fragments. The disease may affect different organs and systems, with multiple clinical features, with cell-mediated immunity playing a significant role in host defence. Peritoneal macrophages from BALB/c mice were stimulated with Brazilian or Bulgarian propolis and subsequently challenged with P, brasiliensis. Data suggest an increase in the fungicidal activity of macrophages by propolis stimulation, independently from its geographic origin, (C) 2002 Elsevier B.V. Ireland Ltd. All rights reserved.

Effects of Brazilian and Bulgarian propolis on bactericidal activity of macrophages against Salmonella Typhimurium

Propolis has been used in folk medicine since ancient times due to its, many biological properties: such as antimicrobial. antinflammatory, antioxidant, immunomodulatory activities, among others. 'Macrophages play an important role in the early phase of Salmonella infection. In this work, macrophages were prestimated with Brazilian or Bulgarian propolis and subsequently challenged with Salmonella Typhimurium at different macrophage/bacteria ratio. After 60 min of incubation. cells were harvested with Triton-X to lyse the macrophages. To assess the bactericidal activity. The number of colony-forming units (CFU) of S. typhimurium was determined by plating 0.1 mL in 'Mueller Hinton agar. After 24 h. CFU were counted. and the percentage of bactericidal activity was obtained. Propolis from Brazil and Bulgaria enhanced the bactericidal activity of macrophages, depending on its concentration. Brazilian propolis seemed to be more efficient than that from Bulgaria. because of their different chemical composition. In Bulgaria, bees collect the material mainly from the bud exudate of poplar tree, while in Brazil, Baccharis dracunculifolia DC. was shown to be the main propolis source. Our data also showed that the increased bactericidal activity of macrophages involved the participation of oxygen (H2O2) and nitrogen (NO) intermediate metabolites. (C) 2004 Elsevier B.V. All rights reserved.

Propolis: Effect of different concentrations, extracts and intake period on seric biochemical variables

Propolis is a resinous substance produced by honeybees that possesses many biological activities, such as antitumor, antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory, among others. The purpose of the present study was to investigate the biochemical profile of propolis-treated rats to observe whether propolis might lead to side effects after administration. Three different treatments were analyzed: (1) rats were treated with different concentrations of propolis (1, 3 and 6 mg/kg/day) during 30 days; (2) rats were treated with I mg/kg/day of ethanolic or water extracts of propolis (EEP, WEP) during 30 days; (3) rats were treated with I mg/kg/day of ethanolic extract of propolis during 90 and 150 days. Our results demonstrated no alterations in the seric levels of cholesterol, HDL-cholesterol, total lipids, triglycerides and in the specific activity of aminotransferases (AST) and lactic dehydrogenase (LDH) of propolis-treated groups when compared to controls. on the basis of our findings, since propolis does not induce any significant change in seric parameters, it is claimed that long-term administration of propolis might not have any cardiac injury. (c) 2005 Elsevier B.V.. All rights reserved.

Tobacco Smoke Induces Ventricular Remodeling Associated with an Increase in NADPH Oxidase Activity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

In vitro cytotoxic activity of Baccharis dracunculifolia and propolis against HEp-2 cells

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anti-poliovirus activity of Baccharis dracunculifolia and propolis by cell viability determination and real-time PCR

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Calcaneal Tendon Regions Exhibit Different MMP-2 Activation After Vertical Jumping and Treadmill Running

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

Finasteride treatment alters MMP-2 and-9 gene expression and activity in the rat ventral prostate

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