title: Functional and biochemical evidence indicating beneficial effect of Melatonin and Nicotinamide alone and in combination in experimental diabetic neuropathy.
abstract: Oxidative stress resulting in excessive generation of ROS is a compelling initiator of DNA damage along with damage to various cellular proteins and other macromolecules. Poly(ADP-ribose) polymerase (PARP) activation in response to DNA damage, stirs an energy-consuming cellular metabolic cycle; culminating into cell death. The present study was designed to determine the effect of combining an antioxidant, Melatonin and a PARP inhibitor, Nicotinamide on the hallmark deficits developing in diabetic neuropathy (DN). Streptozotocin (STZ, 55 mg/kg, i.p.) was administered to induce diabetes. Six weeks post diabetes induction, two week treatment with Melatonin (3 and 10 mg/kg) and Nicotinamide (100 and 300 mg/kg) either alone or in combination was given. Effect of these interventions on the functional, behavioral and biochemical changes caused by hyperglycemia were studied in treated animals. Melatonin and Nicotinamide alone as well as in combination ameliorated the functional deficits along with improvement in pain parameters. The combination also demonstrated an essential reversal of biochemical alterations. Nitrotyrosine and Poly ADP Ribose (PAR) immunopositivity was significantly decreased in sciatic nerve micro-sections of treatment group. The results of this study advocate that simultaneous inhibition of oxidative stress-PARP activation cascade may prove useful for the pharmacotherapy of DN.
authors.affiliation: Molecular Neuropharmacology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Punjab-160062, India.
authors.forename: Geeta
authors.initials: G
authors.lastname: Negi
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Kumar
authors.forename: Ravinder K
authors.initials: RK
authors.lastname: Kaundal
authors.forename: Anil
authors.initials: A
authors.lastname: Gulati
authors.forename: Shyam S
authors.initials: SS
authors.lastname: Sharma
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D003929:Diabetic Neuropathies / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006930:Hyperalgesia / Q000188:drug therapy / Q000503:physiopathology; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008550:Melatonin / Q000627:therapeutic use*; D009431:Neural Conduction / Q000187:drug effects; D009536:Niacinamide / Q000627:therapeutic use*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects; D012584:Sciatic Nerve / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology; D013311:Streptozocin; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D014803:Vitamin B Complex / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D014803:Vitamin B Complex; D009536:Niacinamide; C002744:3-nitrotyrosine; D014443:Tyrosine; D013311:Streptozocin; D011065:Poly(ADP-ribose) Polymerases; D008550:Melatonin