title: L-Theanine healed NSAID-induced gastric ulcer by modulating pro/antioxidant balance in gastric ulcer margin.
abstract: L-Theanine is a unique non-protein-forming amino acid present in tea [Camellia sinensis (L.) O. Kuntze]. In the present work, we evaluated the healing effect of L-theanine on NSAID (indomethacin)-induced gastric ulcer. Histology of the stomach tissues revealed maximum ulceration on the third day after indomethacin administration (18 mg/kg, single dose p.o.) which was accompanied by increased lipid peroxidation; protein carbonylation; Th1 cytokine synthesis, and depletion of thiol, mucin, prostaglandin (PG) E, Th2 cytokine synthesis; and total antioxidant status in mice. L-Theanine healed gastric ulcer at a dose of 10 mg/kg b.w. but aggravated the ulcerated condition at a higher dose of 40 mg/kg b.w. At 10 mg/kg b.w., L-theanine significantly alleviated the adverse oxidative effect of indomethacin through enhanced synthesis of PGE2 by modulation of cyclo-oxygenase-1 and 2 [COX-1 and COX-2] expression, Th1/Th2 cytokine balance, and restoration of cellular antioxidant status at the gastric ulcer margin. The present study revealed for the first time the dose-dependent biphasic effect of a natural neuroprotective agent, L-theanine, on gastric ulcer disease.
authors: Central Research Laboratory, Department of Biochemistry, K.P.C. Medical College and Hospital, Kolkata, 700032, India, sirshendu.chatterjee@gmail.com.
authors: Sirshendu
authors: S
authors: Chatterjee
authors: Ananya
authors: A
authors: Chatterjee
authors: Surmi
authors: S
authors: Roy
authors: Biswajit
authors: B
authors: Bera
authors: Sandip K
authors: SK
authors: Bandyopadhyay
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000633:toxicity*; D000975:Antioxidants / Q000378:metabolism; D005971:Glutamates / Q000737:chemistry / Q000627:therapeutic use*; D007213:Indomethacin / Q000633:toxicity; D015227:Lipid Peroxidation; D008297:Male; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D013276:Stomach Ulcer / Q000139:chemically induced / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D005971:Glutamates; C026166:theanine; D011451:Prostaglandin-Endoperoxide Synthases; D007213:Indomethacin