Antiulcer Potential

Research studies conducted on chitosan for its antiulcer potential have shown its efficacy in ulcer healing and regenerating of gastric mucosa. It acts as a gastric cytoprotec-tive by accelerating the formation of gastric mucus [54,55]. 

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Fig. 1. Schematic diagram showing the different mechanisms of action proposed for the antiulcer action of flavonoids. 1. Blockade of add secretion by decreasing histamine production or inhibiting the proton pump. 2. Bactericidal effect on H. pylori. 3. Antioxidative activity by scavenging free radicals and preventing ROM formation. 4. Potentiation of the mucosal protective factors. PAF platelet activating factor ROM reactive oxygen metabolites H2 histamine receptor 2 M muscarinic receptor G gastrin receptor.

Additionally there is an increasing interest in carotenoids because of their potentially beneficial health effects, such as provitamin A, anticarcinogenic, antiulcer, antiaging, and antioxidant properties and increased immune responses (27,28). Because the vitamin A potential of cis isomers is less than those of their all-trans counterparts, it is important to distinguish and quantify the various forms (29). According to reports and clinical studies carotenes may be important in the prevention of some forms of cancer (30). Since the National Cancer Institute has recommended an increased intake of food high in carotenoids (31), more detailed information about the carotenoid composition of foodstuffs is desirable. 

Ames and Kovacic [45] studied the electrochemistry of omeprazole, active metabolites and a bound enzyme model, with possible involvement of electron transfer in the antiulcer action of the drug. The active metabolites cyclic sulfenamide and sulfur radical entities, exhibited reduction potentials of 0.3 and 0.2 V, respectively. The value for the bound enzyme model was 0.7 V and that for omeprazole was >1.4 V. The results lend credence to the hypothesis that electron transfer comprises part of the mode of action in addition to H+/K+-ATPase inhibition. 

At least three types of ATP driven H+ pumps may be potentially involved in the regulation of pHi. These are (a) an electrogenic H+ translocating ATPase found in the mammalian distal nephron (b) an electroneutral K+-H+ exchange ATPase that is responsible for acid secretion by gastric cells and (c) a vacuolar H+-ATPase which is responsible for the low pH of endocytic vesicles. The vacuolar H+-ATPase can be inhibited by the macrolide antibiotic bafilomycin Al. The gastric K+-H+-ATPase is inhibited by antiulcer drugs such as omeprazole. 

Patients should be monitored for symptomatic relief of ulcer pain as well as potential adverse effects and drug interactions related to drug therapy. Ulcer pain typically resolves in a few days when NSAIDs are discontinued and within 7 days upon initiation of antiulcer therapy. Most patients with uncomplicated PUD wih be symptom-free after treatment with any one of the recommended antiulcer regimens. 

The goal of HP drug therapy is eradication of the organism. Treatment shonld be effective, well-tolerated, easy to comply with, and cost-effective. HP regimens should have eradication (cure) rates of at least 80% based on intention-to-treat analysis, or at least 90% based on per protocol analysis, and should minimize the potential for antimicrobial resistance. The use of a single antibiotic, bismuth salt, or antiulcer drug does not achieve this goal. However,... 

The lack of gastric irritation [270], the presence of antiulcer activity, and the enhanced anti-inflammatory activity of these complexes make this class of potentially useful antiarthritic drugs particularly promising, since the arthritic syndrome is likely to include gastric ulcers [259, 260]. 

In addition, the documented radioprotectant activity of Cu(II)(3,5-DIPS)2 [505] is consistent with its anti-inflammatory activity [22, 84, 514], which relates to protection against the hematopoietic syndrome, its antiulcer activity [22, 84, 91, 514-516], which relates to its potential ability to protect against the gastrointestinal syndrome, and its anticonvulsant activity [324, 326, 516], which relates to its potential to protect against the central nervous system syndrome. 

Nolinium bromide (351) blocks the entry of K" " in the gastric H+-K+-dependent ATPase, interfering with the enzyme turnover, and is thus potentially useful as an antiulcer agent <87BJ(241)175>. 

Methoxycarbonylamino-6-methylbenzyloxy)-2-methyl-3-(2-propynyl)-imidazo-[l,2-a]-pyridine has been investigated as an imidazo-pyridine derivative and an orally effective antiulcer agent potentially useful as an inhibitor of ATPase. The title compound has been obtained in... 

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