title: Effect of melatonin on secreted and induced matrix metalloproteinase-9 and -2 activity during prevention of indomethacin-induced gastric ulcer.
abstract: Matrix metalloproteinases (MMPs) maintain the crucial role in physiological turnover of extracellular matrix (ECM) proteins in gastric tissues. However, a little is known about the relationship of MMPs with ECM degradation during gastric ulceration and ECM remodeling during healing. Our objective was to investigate the effect of melatonin (N-acetyl-5 methoxytryptamine) on the regulation of MMP-9 and MMP-2 activity during prevention of gastric ulcer. In the present study, biochemical and zymographic methods were used to analyze the mechanism of melatonin in indomethacin-induced gastric ulcer in a rat model. Our studies reveal that melatonin dose-dependently downregulates the expression and secretion of pro-MMP-9 which is induced (approximately 10-fold) during indomethacin-induced gastric ulceration. Furthermore, melatonin prevents gastric ulceration in a dose-dependent manner through upregulation (approximately two- to threefold) of both pro-MMP-2 and active MMP-2 at the level of induction as well as secretion. It also prevents gastric ulcers by blocking glutathione depletion and lipid peroxidation in cytosolic and microsomal fractions. The novel findings of this study are attributed to the attenuation of the pro-MMP-9 and increase of MMP-2 activity by pretreatment with melatonin. The finding defines one of the MMP-mediated pathways for melatonin's action in gastric ulcer.
authors.affiliation: Department of Physiology, Indian Institute of Chemical Biology, Kolkata, India.
authors.forename: Krishnendu
authors.initials: K
authors.lastname: Ganguly
authors.forename: Pallab
authors.initials: P
authors.lastname: Maity
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: Snehasikta
authors.initials: S
authors.lastname: Swarnakar
mesh_terms: D000818:Animals; D004790:Enzyme Induction / Q000502:physiology; D007213:Indomethacin / Q000633:toxicity*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000378:metabolism*; D008550:Melatonin / Q000627:therapeutic use*; D018384:Oxidative Stress / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013276:Stomach Ulcer / Q000139:chemically induced* / Q000201:enzymology / Q000517:prevention & control*
chemical_list: D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D008550:Melatonin; D007213:Indomethacin