Effect of Hydrotalcite on Indometacin-Induced Gastric Injury in Rats

BACKGROUND AND AIMS: Hydrotalcite plays an important role in the therapy of gastric ulcer induced by nonsteroidal anti-inflammatory drugs (NSAIDs), but little is known about the mechanism. We designed two experiments to study the preventive and curative effects of hydrotalcite on NSAIDs-related gastric injury in rats and to investigate the relationship between the protective and curative mechanism of hydrotalcite and the secretion of epidermal growth factor (EGF)/prostaglandin E2 (PGE2). METHODS: Two experiments were separately designed to evaluate the preventive and curative effects of hydrotalcite. A total of 25 male rats and 25 female rats were randomly divided into five groups (vehicle group, model group, omeprazole group, hydrotalcite group, and ranitidine group) in each experiment. Rats were treated with indomethacin by gavage to build the model of acute gastric mucosal injury. The concentrations of EGF and PGE2 in blood specimens and mucosal injury indexes by gross inspection were measured and an immunohistochemical technique was also employed to test the levels of EGF, cyclooxygenase-1 (COX-1), and cyclooxygenase-2 (COX-2) in gastric mucosa. RESULTS: Comparing with model group in both preventive and curative experiments, hydrotalcite decreased the gastric injury in the mucosa of stomach significantly (7±4.5 vs. 16±11.25, 1.5±2 vs. 2.5±6; P<0.01, P<0.05). The levels of EGF and PGE2 in blood serum were markedly higher in hydrotalcite group than that in model group and ranitidine group in preventive experiment (574.39±34.28 vs. 486.22±41.73, 488.07±24.44; P<0.01, P<0.01). The expression levels of COX-2 in gastric mucosa were also higher in hydrotalcite group than that in model group in both preventive and therapeutic experiments (12±4 vs. 9±6, 14±7 vs. 9±4; P<0.01, P<0.05). CONCLUSIONS: Hydrotalcite promotes gastric protection and healing via several mechanisms, including increased levels of PGE2 in blood serum, activation of EGF, and antagonising the inhibition of cyclooxygenase (COX) caused by NSAIDs.