The strong anti-ulcerogenic activity of ZHA administered chronically, has been presently demonstrated (compared also to the previously demonstrated, in the same experimental conditions, ketoprofen-induced ulcerogenic activity) [15,16]. This indicates, that chronic ZHA treatment (in the present data) augments the single or sub-chronic ZHA effect [8]. This data is in line with the anti-ulcerogenic activity of ZHA in the other model concerning gastric ulcer [17]. A dose-dependent effect induced by 7 or 14 days (but not by 3 days) administration of ZHA was observed [17]. Laboratory animals fed with zinc exhibit decreased the antiinflammatory drugs – induced damage of the gastric mucosa [14,18]. Similar results were obtained in a clinical trial on a group of patients at risk of rheumatoid disease. Carnosine zinc complex (polaprezinc) is used for the treatment of gastric ulcers [19]. There is no clear evidence which mechanism(s) is/are responsible for the gastroprotective properties of this drug: antioxidant activity, increasing the production of endogenous PG in the stomach, exerting a stabilizing effect on biological membranes or/and increasing the secretion of gastric mucosa [17]. Other experiments have shown that the administration of zinc sulphate to Helicobacter pylori-infected individuals, accelerates the healing of gastric mucosa [20]. Recent research shows that intragastric administration of ZHA to rats with induced gastric ulcers, significantly improves the condition of the mucosa. It has been observed that the administration of this salt, leads to an increased concentration of zinc ions in the area affected by ulcers. Moreover, a visible reduction of ulcers, reduced secretion of gastric acid, gastrin increase and an increase in gastric microcirculation were reported [17]. It is estimated that such actions result in the induction of a proliferation and differentiation of cells in the treatment of ulcers. This data may indicate a trophic effect of zinc on the gastric mucosa, although its exact mechanism of action remains unknown. Because this anti-ulcerogenic effect of ZHA was not related to stomach zinc concentration (in the present data) [17], the enhanced activity of endogenous factors (possibly originally from the stomach) involved in these processes may take part in this effect, which is worthy of further examinations.
In summary, the present study demonstrated for the first time that chronic treatment with zinc salt exhibits the anti-inflammatory