Multielement analysis of plant extracts with potential use in the treatment of peptic ulcers by synchrotron radiation total reflection X-ray fluorescence

Some plants popularly employed for the treatment of peptic ulcers have proved to be attractive sources of new drugs. Despite extensive research, the pharmacological and toxicological potentials of these plants are not fully understood. In this context, the aim of this work was to analyze the multielemental composition of the methanolic extracts of three of those plants, Alchornea glandulosa (AG), Davilla elliptica (DE) and Davilla nitida (DN), with the intention of contributing to the understanding of the mechanisms of action of these extracts. For this purpose, we used the analytical technique of total reflection X-ray fluorescence (TXRF) by synchrotron radiation at the Brazilian Synchrotron Light Source (LNLS/CNPEM). It was possible to determine the concentrations of the elements: P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb and Br in all of the samples. Selenium (Se) was detected only in the DN extract. An inverse relationship between the concentrations of elements with proven effectiveness and the gastroprotective activity of extracts considering induction protocols with ethanol and non-steroidal anti-inflammatory drugs (NSAIDs) was obtained. This data suggests that the function of the extract is not only associated with providing the elements for restoring the gastric mucosa but that it also promotes the displacement of these elements from other parts of the mucosa to the damaged area. Correlations between the concentrations of the elements were also obtained. In the DE extract, which is the most effective extract for both induction protocols, the obtained correlations were above 70% among almost all of the elements, and no anticorrelations were found. For the other two extracts, in the less effective extract (AG) anticorrelations above 70% were predominantly found. Meanwhile, in the DN extract, a few high anticorrelations were found, which may explain its intermediate stage of effectiveness

Atividade antiulcerogenica da desidrocrotonina e do oleo essencial obtidos a partir das cascas de Croton cajucara Benth, uma planta da familia Euphorbiacear

Orientadores: Alba R. M. Souza Brito, Domingos Savio NunesTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Croton cajucara Benth. (sacaca) é uma espécie vegetal da região amazônica popularmente utilizada para o tratamento de distúrbios do trato digestivo. Foram investigadas a atividade antiulcerogênica e o mecanismo de ação dos constituintes majoritários obtidos a partir das cascas: o óleo essencial e a desidrocrotonina - OHC (uma sesquiterpenolactona presente em grande quantidade nas cascas). Através de modelos de úlceras agudas, induzidas por agentes como etanol, HCI/etanol, ligadura do piloro, indometacina e estresse, em ratos e camundongos, foi possível constatar que o óleo essencial e a OHC reduziram significativamente as lesões ulcerativas nos diversos modelos estudados. A partir destes resultados foram investigados os possíveis mecanismos antiulcerogênicos da OHC e do óleo essencial. A OHC não foi capaz de aumentar a produção de muco em células glandulares isoladas de estômago de ratos, e nem de apresentar atividade antioxidante em mitocôndrias isoladas de fígado de rato. Por outro lado, a OHC antagonizou, de modo não-competitivo, os receptores H2 de histamina no átrio isolado de cobaia e M1 no fundo de estômago isolado de rato; adicionalmente, apresentou um aumento na produção/síntese de PGE2 pelas células da mucosa gástrica em ratos. A OHC não foi capaz de cicatrizar as úlceras pré-estabelecidas em ratos após 14 dias de tratamento. O óleo essencial alterou a acidez e o volume do suco gástrico quando administrado por via intraduodenal, o que demonstra uma ação sistêmica; aumentou a produção de muco pelas células glandulares do estômago de ratos e aumentou a produção/síntese de PGE2 pelas células da mucosa gástrica em ratos. Em adição, o óleo essencial foi capaz de cicatrizar (32% de cura) as úlceras pré-estabelecidas em ratos, após 14 dias de tratamento, com a mesma potência da cimetidina. Os resultados obtidos indicam que a utilização popular do infuso de sacaca, o qual contém DHC e óleo essencial, em distúrbios gastrointestinais, está perfeitamente justificado pela atividade de seus constituintes majoritáriosAbstract: Croton cajucara Benth. (sacaca) is a plant species growing in the Amazon region which is popularly used to treat disorders of the digestive tract. We investigated the antiulcerogenic activity and the mechanism of action of the major constituents of the bark of the plant, i.e., the essential oil and dehydrocrotonin (OHC, a sesquiterpene lactone present in large amounts in the bark). Using acute ulcer models induced by agents such as ethanol, HCllethanol, pylorus ligature, indomethacin, and stress in rats and mice, we observed that the essential 011 of the plant and OHC significantly reduced the ulcerative lesions in the various models studied. On the basis of these results, we investigated the possible mechanisms of action involved in the antiulcerogenic action of OHC and of the essential oil. OHC did not increase mucus production by glandular cells isolated from the stomach of rats and had no antioxidant activity on mitochondria isolated from the liver of rats. On the other hand, OHC antagonized in a noncompetitive manner the H2 receptors of histamine in the isolated guinea pig atrium and the M1 receptors, in the isolated rat stomach. Furthermore, OHC caused an increased PGE2 production/synthesis by the cells of the gastric mucosa of rats. OHC did not heal preestablished ulcer in rats after 14 days of treatment. The essential oil altered the acidity and volume of gastric juice when administered intraduodenally, demonstrating a systemic action, increased the production of mucus by glandular cells of the rat stomach, and increased PGE2 production/synthesis by cells of the rat gastric mucosa. In addition, the essential oil was able to heal (a 32% cure rate) preestablished ulcers in rats after 14 days of treatment with the same potency as cimetidine. The present results indicate that the popular use of sacaca infusion containing the essential oil to treat gastrointestinal disorders is perfectly justified by the activities of its major constituentsDoutoradoDoutor em Ciências Biológica

Healing Actions of Essential Oils from Citrus aurantium and d-Limonene in the Gastric Mucosa: The Roles of VEGF, PCNA, and COX-2 in Cell Proliferation

Previous studies have described the gastroprotective effects of essential oils that are derived from Citrus aurantium (OEC) and its main compound d-limonene (LIM) in a model of chemically induced ulcers in rats. However, these studies do not address the compound's healing effects on the gastric mucosa. Thus, the aim of this work was to evaluate the healing activity of OEC and LIM in acetic acid-induced gastric ulcers in rats, a model that reproduces human chronic ulcers. The obtained results demonstrated that lower effective doses of OEC (250mg/kg) and LIM (245mg/kg) induced gastric mucosal healing with a cure rate of 44% and 56%, respectively, compared with the control group (P<.05). During the 14 days of OEC or LIM treatment, none of the groups demonstrated toxicity in terms of body and organ weight or serum biochemical parameters. Both OEC and LIM treatment promoted an increase in epithelial healing, as confirmed by immunohistochemistry, which was greater in the animals that were treated with the positive control. In addition, both treatments increased cellular proliferation as measured by proliferating cell nuclear antigen and cyclooxygenase 2 expression in the gastric mucosa, vascular endothelial growth factor-mediated blood vessel formation in the margin of the ulcer, and production of gastric mucus, which fortifies the gastric protective barrier. We concluded that OEC and LIM, two common flavoring agents, promote gastric mucosal healing without any apparent toxic effect, resulting in better gastric epithelial organization in the treated rats.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Effect of Mouriri pusa extracts on experimentally induced gastric lesions in rodents: Role of endogenous sulfhydryls compounds and nitric oxide in gastroprotection

Several plants are used in folk medicine to treat gastrointestinal disorders. Mouriri pusa Gardn. (Melastomataceae) is a medicinal plant commonly used in the central region of Brazil against gastric ulcer. Two organic extracts methanolic (MeOH) and dichloromethane (DCM) obtained by sequential extraction from the leaves of Mouriri pusa were evaluated for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCl/60% EtOH, absolute ethanol, non-steroidal anti-inflammatory drug, stress and pylorus ligature) in mice and rats. The best results were obtained after pretreatment with MeOH extract whereas the DCM extract did not show the same significant antiulcerogenic activity. No acute toxicity was observed in animals treated with 5 g/kg, p.o. of MeOH extract. The mechanism involving the antiulcerogenic action of MeOH extract seemed to be related to NO generation and also suggested the effective participation of endogenous sulfhydryl group in the gastroprotective action. Phytochemical investigation of the MeOH extract of Mouriri pusa yielded tannins, flavonoids and (-)-epicatechin. The presence of these phenolic compounds probably would explain the antiulcerogenic effect of the polar extract of Mouriri pusa leaves. (c) 2006 Elsevier B.V.. All rights reserved

Constituents and antiulcer effect of Alchornea glandulosa: Activation of cell proliferation in gastric mucosa during the healing process

Alchornea glandulosa (Euphorbiaceae) is a plant used in folk medicine as an antiulcer agent. Rats pretreated with methanolic extract obtained from the leaves of A. glandulosa (AG) showed a dose-dependent effect and significant reduction of gastric ulcers induced by absolute ethanol at the doses of 500 (57%) and 1000 mg/kg (35%) in relation to the control group. Pretreatment of mice with AG (500, 1000 mg/kg, p.o.) showed dose-dependent activity and significantly decreased the severity of lesions caused by HCl/ethanol and by non steroidal anti inflammatory drug-induced gastric lesions. Pretreatment with AG also induced antisecretory action via local and systemic routes and a significant decrease in the total gastric acid content. The gastroprotective effects of AG involved the participation of nitric oxide and increased levels of endogenous sulfhydryl compounds, which are defensive mechanisms of the gastrointestinal mucosa against aggressive factors. The ability of AG to heal gastric ulcers was evaluated after 14 consecutive days of treatment. The results showed that single oral administrations of AG (250 mg/kg/once daily) potently stimulates gastric epithelial cell proliferation that contributes to the accelerated healing of gastric ulcers induced by acetic acid. In addition, no subacute toxicity (body weight gain, vital organs, and serum biochemical parameters) was observed during treatment with AG. Phytochemical investigation of AG led to the isolation of myricetin-3-O-alpha-L-rhamnopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, quercetin-3-O-beta-D-galactopyranoside, quercetin, amentoflavone, methyl gallate, gallic acid, and pterogynidine. We also established the phytochemical profile of AG with the quantification of total phenolic compounds. These compounds may contribute to the observed antiulcerogenic effects of AG

The Anti-Inflammatory Effects of the Methanolic Extract and Fractions from Davilla elliptica St. Hil. (Dilleniaceae) on Bothrops jararaca Envenomation

Inflammation and haemorrhage are the main characteristics of tissue injury in botropic envenomation. Although some studies have shown that anti-venom prevents systemic reactions, it is not efficient in preventing tissue injury at the site of the bite. Therefore, this work was undertaken to investigate the anti-inflammatory effects of the methanolic extract and fractions from D. elliptica and to evaluate the role of matrix metalloproteinases (MMPs) in this process. Effects of the extract and fractions from D. elliptica were evaluated using a carrageenan-induced paw oedema model in rats, and leukocyte rolling was visualized by intravital. The quantification of MMPs activities (MMP-2 and MMP-9) extracted from the dermis of mice treated with extract and fractions alone or incubated with venom was determined by zymographic analyses. Our results show that intraperitoneal (i.p.) injection of fractions significantly reduced paw oedema after the carrageenan challenge. Treatment with the tannins fraction also resulted in considerable inhibition of the rolling of leukocytes and this fraction was able to decrease the activation of MMP-9. These results confirmed the anti-inflammatory activity of the methanolic extract and tannins fraction of D. elliptica and showed that the dermonecrosis properties of B. jararaca venom might be mediated through the inhibition of MMP-9 activity.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Evaluation of Strychnos pseudoquina St. Hil. leaves extract on gastrointestinal activity in mice

Strychnos pseudoquina St. Hil. (Loganiaceae) was investigated for its ability to protect the gastric mucosa against injuries caused by non-steroidal anti-inflammatory drugs (piroxicam) and a necrotizing agent (HCl/EtOH) in mice. The MeOH extract and enriched alkaloidic fraction (EAF) provided significant protection in experimental models wheer used at doses of 250 and 1000 mg/kg. In vivo tests were carried out to evaluate for possible toxic effects and no mortality was observed up to the 5 g/kg dose level. Phytochemical investigation led to the isolation of a new indole alkaloid, which elucidated the observed pharmacological effects. © 2005 Pharmaceutical Society of Japan

Gastroprotective effects (in rodents) of a flavonoid rich fraction obtained from Syngonanthus macrolepsis

Objectives: Syngonanthus macrolepis, popularly known in Brazil as sempre-vivas', is a plant from the family Eriocaulaceae, it is found in the states of Minas Gerais and Bahia. The species contains a variety of constituents, including flavonoids with gastroprotective effect. In this work, a flavonoid-rich fraction (Sm-FRF) obtained from scapes of S.macrolepis was investigated for preventing gastric ulceration in mice and rats.MethodsThe activity was evaluated in models of induced gastric ulcer (absolute ethanol, stress, non-steroidal anti-inflammatory drugs and pylorus ligation). The cytoprotective mechanisms of the Sm-FRF in relation to sulfhydryl (SH) groups, nitric oxide (NO) and antioxidant enzymes were also evaluated.Key findingsThe Sm-FRF (100mg/kg, p.o.) significantly reduced gastric injury in all models, and did not alter gastric juice parameters after pylorus ligation.ConclusionsThe results indicate significant gastroprotective activity for the Sm-FRF, which probably involves the participation of both SH groups and the antioxidant system. Both are integral parts of the gastrointestinal mucosa's cytoprotective mechanisms against aggressive factors

Geraniol-a flavoring agent with multifunctional effects in protecting the gastric and duodenal mucosa

Geraniol is an acyclic monoterpene alcohol commonly used as a flavoring agent. The present study was undertaken to investigate antiulcerogenic effects of geraniol and to determine the possible mechanisms involved in this action. In the model of the ethanol-induced ulcer, treatment of rats with geraniol by oral route significantly inhibited gastric lesions by 70 % (7.50 mg/kg) to 99 % (200 mg/kg). Analysis of the gastric tissue of rats treated with geraniol (7.50 mg/kg) revealed that total glutathione content levels (GSH) increased and levels of myeloperoxidase (MPO) decreased in the gastric mucosa. Oral treatment with geraniol significantly decreased the number of ulcerative lesions induced by ischemia/reperfusion injury by 71 % and the duodenal ulcers induced by cysteamine by 68 %. The action of geraniol was mediated by the activation of defensive mucosa-protective factors such as the nitric oxide (NO) pathway, endogenous prostaglandins, increased mucus production, increased sulfhydryl compounds, antioxidant properties and the stimulation of calcitonin gene-related peptide (CGRP) release through the activation of transient receptor potential vanilloid (TRPV). The multifaceted gastroprotective mechanisms of geraniol represent a promising option for the treatment of gastric and duodenal mucosa injury.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq