Sesamol Attenuates Diclofenac-Induced Acute Gastric Mucosal Injury via Its Cyclooxygenase-Independent Antioxidative Effect in Rats

We examined the protective effects of sesamol against acute gastric mucosal damage induced in rats by nonsteroidal anti-inflammatory drug diclofenac (DLF). We also measured the ulcer index, nitrite, iNOS, lipid peroxidation, hydroxyl radical, superoxide anion, reduced glutathione levels, prostaglandin E2, mucus, and cyclooxygenase activity in the rat mucosa. Sesamol attenuated gastric ulcer, nitrite, and iNOS in DLF-treated stomachs. Sesamol reduced mucosal lipid peroxidation and hydroxyl radical levels; however, neither DLF nor sesamol affected mucosal superoxide anion production. In addition, sesamol significantly maintained the reduced mucosal glutathione levels in DLF-treated stomachs of rats. Sesamol did not affect mucosal mucus production, but it further decreased DLF-induced mucosal prostaglandin E2 generation and cyclooxygenase activity. Therefore, sesamol might protect gastric mucosa against DLF-induced injury by inhibiting hydroxyl radical-associated lipid peroxidation. In addition, the cyclooxygenase pathway may not be involved in sesamol's gastric mucosal protection.