Ulcerogenic effects of NSAIDs on gastric mucosa : comparison between selective and non-selective Cox2 inhibitors ; indomethacin VS rofecoxib

الملخص EN

Background: The central pathogenic mechanism in NSAID-induced gastro-duodenal toxicity lies in their ability to inhibit the synthesis of prostaglandins by gastric mucosa through inhibition of cyclooxygenase enzyme (Cox).

There are two isoforms of Cox enzyme: Cox-1 and Cox-2.

The gastroprotective effects of prostaglandins are mediated by Cox-1 while the inflammatory effects are mediated by Cox-2.

NSAIDs inhibit synthesis of prostaglandins, resulting in toxic effects on gastric mucosa and beneficial anti-inflammatory effects.

Conventional NSAID are non-selective inhibitors of cyclo-oxygenase and thus, they promote the antiinflammatory response and at the same time inhibit gastric protective effects of prostaglandins.

To overcome this problem, drugs that have little or no Cox-1 inhibitory activity have been developed and a new generation of NSAIDs has emerged.

Aim of the study: The aim of this study is to evaluate the morphological effects of Rofecoxib on the gastric mucosa by comparing them with those produced by Aspirin and Indomethacin.

Material and Methods: 40 Spargue-Dawely rats were used in this study.

The animals were divided into four subgroups, each group included ten animals.

Group I received no treatment and considered as control, group II received Aspirin, group III received Indomethcine, and group IV received Rofecoxib.

After one month of treatment the animals were sacrificed and the gastric mucosa in each animal was examined macroscopically and microscopically.

Results: Aspirin produced the most sever gastric lesions mainly in the pylorus, which take the form of erosions and ulcerations.

Rofecoxib caused the least gastric lesions mainly in the body of the stomach.

Indomethacin caused an intermediate degree of gastric damage mainly in the body of the stomach.

Conclusion: Aspirin and Indomethacine produced the most sever effect on gastric mucosa, these effects take the form of gastric erosion and ulceration that involved mainly the pylorus and the body of the stomach respectively.

Rofecoxib, showed the least gastric lesion as compared to Aspirin and Indomethacin.