Background: Aspirin or acetylsalicylic acid (ASA) is among the most popular used drugs in the world. Gastric lesions are one of aspirin's often-occurring side effects. Silymarin is a natural compound that exhibits effects against inflammation, oxidation, and apoptosis.
Aim of the work: This study was conducted to evaluate ASA-induced gastric mucosal damage and the potential ameliorative role of silymarin.
Material and Methods: Thirty adult male albino rats were randomly divided into three equal groups: a control group (subdivided into       a negative control group without any medication and a positive control group that received distilled water/day orally by gastric gavage for 2 weeks), ASA-treated group (received 200 mg ASA/kg b.w./day orally for 2 weeks), and ASA+silymarin-treated group (received 200 mg ASA/kg b.w./day in addition to 50 mg silymarin/kg b.w./day, orally for 2 weeks). At the end of the experiment, the rats were anaesthetized and sacrificed. The stomach was removed, opened, and processed for histological and iNOS immunohistochemical evaluation. Area % of collagen fibres and iNOS immune expression and gastric mucosal thickness of all animal groups were measured and compared.  
Results: The ASA induced gastric mucosal histological changes in the form of erosion, degeneration, vacuolization of cells, and dilatation of blood capillaries. The area % of collagen fibres and iNOS was significantly increased and gastric mucosal thickness was significantly decreased in ASA-treated groups in comparison to the control. These changes were improved in the ASA+silymarin-treated group.
Conclusion: ASA induced gastric mucosal injuries and the concomitant administration of silymarin could ameliorate these effects.