Ulcer healing and mechanism(s) of action involved in the gastroprotective activity of fractions obtained from Syngonanthus arthrotrichus and Syngonanthus bisulcatus

Abstract Background Syngonanthus arthrotrichus and Syngonanthus bisulcatus, currently known for Comanthera aciphylla (Bong.) L.R.Parra & Giul. and Comanthera bisulcata (Koern.) L.R. Parra & Giul, popularly known in Brazil as “sempre-vivas,” are plants from the family Eriocaulaceae. They are found in the states of Minas Gerais and Bahia. The species are known to be rich in flavonoids to which their gastroprotective activity has been attributed. In this research, experimental protocols were performed to elucidate the associated mechanisms of action. Methods The activity was evaluated using induced gastric ulcer models (acetic acid and ethanol-induced gastric lesions in NEM or L-NAME pre-treated mice, and by ischemia/reperfusion). Antioxidant enzymes, serum somatostatin, and gastrin were also evaluated. Results In chronic gastric ulcers, a single daily oral dose of Sa-FRF or Sb-FRF (100 mg/kg body wt.) for 14 consecutive days accelerated ulcer healing to an extent similar to that seen with an equal dose of cimetidine. The pre-treatment of mice with NEM (N-ethylmaleimide) or L-NAME (N-nitro-L-arginine) abolished the protective activity of Sa-FRF, Sa-FDF, Sb-FDF and Sb-FRF or Sa-FRF and Sb-FRF, respectively, which indicates that antioxidant compounds and nitric oxide synthase activity are involved in the gastroprotective. Sa-FRF and Sb-FRF (100 mg/kg p.o) protected the gastric mucosa against ulceration that was induced by ischemia/reperfusion (72 and 76 %, respectively). It also decreased lipid peroxidation and restored total thiols in the gastric wall of mice that had been treated with ethanol. When administered to rats submitted to ethanol-induced gastric lesions, Sa-FRF and Sb-FRF (100 mg/kg, p.o.) increased the somatostatin serum levels, while the gastrin serum levels were proportionally decreased. Conclusions The results indicate significant healing effects and gastroprotective activity for the Sa-FRF and Sb-FRF, which probably involves the participation of SH groups, nitric oxide (NO), the antioxidant system, somatostatin, and gastrin. All are integral parts of the gastrointestinal mucosa’s cytoprotective mechanisms against aggressive factors

Antiulcerogenic action of ethanolic extract of the resin from Virola surinamensis Warb. (Myristicaceae)

Ethnopharmacological relevance: Virola surinamensis (Myristicaceae), popularly known as mucuiba, ucuuba or ucuuba do igapo is a large tree that grows abundantly in Varzea forest and on river banks in the Brazilian states of Amazonas and Tocantins. The resin obtained by cuts on the stem bark is a reputed folk remedy in its natural form for the treatment of ulcer, gastritis inflammation and cancer.Aim of the study: The present work evaluated the pharmacological activity of the resin obtained from bark of V surinamensis as antiulcerogenic in experimental in vivo model in order to observe whether its traditional use is justified.Materials and methods: The preventive action of ethanolic extract of V surinamensis was evaluated in experimental in vivo models in rodents that simulated this disease in human gastric mucosa.Results: Oral administration of acidified ethanol solution produced severe hemorrhagic lesions in glandular mucosa with ulcerative lesion of 50 +/- 11.5 mm. In animals pretreated with V surinamensis (500 mg/kg, p.o.) a significant inhibition of mucosal injury of 2.40 +/- 0.56 mm (95% inhibition) was detected. The V. surinamensis, at the same dose, also reduced significantly (p < 0.05) the formation of gastric lesions induced by indomethacin (39%), stress (45%) and by pylorus ligature in mice (31%) when compared to animals treated with vehicle. The extract from V surinamensis exerts gastroprotective action only when this extract contacts gastric mucosa (oral route) with. increased pH values and reduced H(+) concentration of gastric contents. The ethanolic extract of V surinamensis resin was analyzed by TLC and spectrometric methods (NMR and ES-MS) and the main constituent of this extract was epicatechin.Conclusions: We suggest that the epicatechin present in V surinamensis resin may be among active principles responsible for the antiulcer activity shown by the tested resin but their used suggest carefulness because toxicological symptoms mentioned by population. (C) Published by Elsevier B.V

Gastroprotective effect of the ethanolic extract and fractions obtained from syngonanthus bisulcatus Rul

Syngonanthus bisulcatus Rul., popularly known in Brazil as sempre-vivas chapadeira, is a plant of the family Eriocaulaceae, it is found in the states of Minas Gerais and Bahia. In this work, the ethanolic extract (EtOHE), flavonoid-rich (FRF), and flavonoid-deficient (FDF) fractions obtained from scapes of S. bisulcatus were investigated for gastroprotection in both rats and mice. The activity was evaluated in models for induced gastric ulcer (absolute ethanol, stress, non-steroidal anti-inflammatory drugs, and pylorus ligation). The participation of mucus and prostaglandin E2 were also investigated. Sb-EtOHE (50, 100, and 250 mg/kg, p.o.), Sb-FRF (100 mg/kg, p.o.), and Sb-FDF (100 mg/kg, p.o.) significantly reduced gastric injuries in all models. Sb-FRF altered gastric juice parameters after pylorus ligation. Sb-FRF and Sb-FDF (100 mg/kg each, p.o.) significantly increased the amount of adherent mucus in the gastric mucosa. Sb-FRF maintained the mucosal levels of prostaglandin after the administration of indomethacin. The results indicate that Sb-EtOHE, Sb-FRF and Sb-FDF have significant gastroprotective activity. The observed gastroprotective effects of S. bisulcatus probably involve the participation of both mucus and prostaglandins, integral parts of the gastrointestinal mucosa's cytoprotective mechanisms against aggressive factors. © 2013 Reproduction is free for scientific studies.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

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

The anti-ulcerogenic effects of Curatella americana L.

Ethnopharmacological relevance: Curatella americana L. (Dilleneaceae) is a medicinal plant very frequently cited as acting against gastrointestinal disorders in ethnopharmacological inventories of the Cerrado region of Brazil.Aim of the study:The ethanolic extract (CEB)and infusion (BI)of Curatella americana bark were investigated for their ability to prevent and heal ulceration of the gastric mucosa.Materials and methods: The preventive and healing actions of Curatella americana were evaluated in experimental in vivo models in rodents that simulated this disease in human gastric mucosa.Results: CEB significantly decreased the severity of gastric damage formation induced by the combination of several gastroprotective models (HCl/ethanol, indomethacin/bethanecol, absolute ethanol, stress and pylorus ligature). But, unlike CEB, the BI did not exert gastroprotective effect. The gastroprotective action of CEB involved antisecretory action, augmentation of gastric mucus (48%) and participation of endogenous sulfhydryl compounds that increase efficacy of barrier mucosa against injurious agents. CEB also presents effective healing action in chronic gastric disease (1.90 +/- 0.55 vs. 6.86 +/- 0.46 mm(2) in the control) and its action mechanisms consisted of increasing the PGE(2) (40%) and somatostatin levels (269%) while decreasing the gastrin level in rat plasma (79%).Conclusions: The gastroprotective effect and healing action of Curatella americana involved modulation of PGE2, somatostatin and gastrin levels, probably due to the presence of oligomeric and polymeric proanthocyanidins in the bark. (c) 2008 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq