Astragaloside IV protects rat gastric mucosa against aspirin-induced damage

Aspirin (Asp) is commonly used as an anti-inflammatory drug, but the long-term usage of Asp can lead to severe gastrointestinal damage. Thus the co-administering of Asp with another drug that can suppress its side effect while having no impact on its anti-inflammatory activity would be ideal. Astragaloside IV (AST-IV) is a natural anti-inflammatory compound that has been shown to protect rat gastric mucosa from anhydrous ethanol-inflicted damage. In this study, we investigated whether AST-IV could protect rat gastric mucosa against Asp-induced gastric mucosal damage. Wistar rats administered 150mg/kg Asp showed significant damage to the gastric mucosa, as revealed by gastric damage score and histological evaluation. However, this was largely abolished by co-administering Asp and 25mg/kg or 50mg/kg AST-IV. The protective mechanism of AST-IV involved the suppression of Asp-induced inhibition of cycloxygenase-1 (COX-1) expression, prostaglandin E₂ (PGE₂) production, superoxide dismutase (SOD) activity and nitric oxide (NO) production. AST-IV blocked Asp-induced inhibition of SOD activity through preventing Asp from inhibiting the expression of SOD-1, both at the mRNA and protein levels. AST-IV did not appear to interfere with the anti-inflammatory activity of Asp since COX-2 level in model gastritis rats treated with Asp plus AST-IV was equally suppressed as in model gastritis rats treated with Asp alone. The results clearly showed that AST-IV could neutralize the toxicity of Asp while having no impact on its anti-inflammatory activity. AST-IV could therefore be considered as a potential drug for relieving the side effect associated with the long-term usage of Asp.