Attenuation of cysteamine-induced duodenal ulcer with Cochinchina momordica seed extract through inhibiting cytoplasmic phospholipase A2/5-lipoxygenase and activating γ-glutamylcysteine synthetase

J Gastroenterol Hepatol. 2012 Apr:27 Suppl 3:13-22. doi: 10.1111/j.1440-1746.2012.07065.x.

Abstract

Background and aim: Cysteamine is a reducing aminothiol used for inducing duodenal ulcer through mechanisms of oxidative stress related to thiol-derived H(2)O(2) reaction. Cochinchina momordica saponins have been suggested to be protective against various gastric diseases based on their cytoprotective and anti-inflammatory mechanisms. This study was aimed to document the preventive effects of Cochinchina momordica seed extract against cysteamine-induced duodenal ulcer as well as the elucidation of its pharmacological mechanisms.

Methods: Cochinchina momordica seed extract (50, 100, 200 mg/kg) was administrated intragastrically before cysteamine administration, after which the incidence of the duodenal ulcer, ulcer size, serum gastrin level, and the ratio of reduced glutathione (GSH)/oxidized glutathione disulfide (GSSG) as well as biochemical and molecular measurements of cytoplasmic phospholipase A(2) (cPLA(2)), cyclooxygenase-2 (COX-2), 5-lipoxygenase and the expression of proinflammatory genes including IL-1β, IL-6, COX-2 were measured in rat model. Additional experiments of electron spin resonance measurement and the changes of glutathione were performed.

Results: Cochinchina momordica seed extract effectively prevented cysteamine-induced duodenal ulcer in a dose-dependent manner as reflected with significant decreases in either duodenal ulcerogenesis or perforation accompanied with significantly decreased in serum gastrin in addition to inflammatory mediators including cPLA(2), COX-2, and 5-lipoxygenase. Cochinchina momordica seed extract induced the expression of γ-glutamylcysteine synthetase (γ-GCS)-related glutathione synthesis as well as significantly reduced the expression of cPLA(2). Cochinchina momordica seed extract preserved reduced glutathione through increased expressions of γ-GCS.

Conclusion: Cochinchina momordica seed extracts exerted significantly protective effect against cysteamine-induced duodenal ulcer by either cPLA2 inhibition or glutathione preservation.

MeSH terms

  • Animals
  • Anti-Ulcer Agents / isolation & purification
  • Anti-Ulcer Agents / pharmacology*
  • Antioxidants / pharmacology
  • Arachidonate 5-Lipoxygenase / metabolism*
  • Cell Line
  • Cyclooxygenase 2 / metabolism
  • Cysteamine*
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Duodenal Ulcer / chemically induced
  • Duodenal Ulcer / enzymology
  • Duodenal Ulcer / pathology
  • Duodenal Ulcer / prevention & control*
  • Duodenum / drug effects*
  • Duodenum / enzymology
  • Duodenum / pathology
  • Enzyme Activation
  • Enzyme Activators / isolation & purification
  • Enzyme Activators / pharmacology*
  • Gastrins / blood
  • Glutamate-Cysteine Ligase / metabolism*
  • Glutathione / metabolism
  • Inflammation Mediators / metabolism
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / enzymology
  • Intestinal Mucosa / pathology
  • Lipoxygenase Inhibitors / isolation & purification
  • Lipoxygenase Inhibitors / pharmacology*
  • Male
  • Momordica* / chemistry
  • Oxidation-Reduction
  • Oxidative Stress / drug effects
  • Phospholipases A2, Cytosolic / antagonists & inhibitors*
  • Phospholipases A2, Cytosolic / metabolism
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Seeds
  • Time Factors

Substances

  • Anti-Ulcer Agents
  • Antioxidants
  • Enzyme Activators
  • Gastrins
  • Inflammation Mediators
  • Lipoxygenase Inhibitors
  • Plant Extracts
  • Cysteamine
  • Arachidonate 5-Lipoxygenase
  • Cyclooxygenase 2
  • Ptgs2 protein, rat
  • Phospholipases A2, Cytosolic
  • Glutamate-Cysteine Ligase
  • Glutathione