title: Concurrent targeting of nitrosative stress-PARP pathway corrects functional, behavioral and biochemical deficits in experimental diabetic neuropathy.
abstract: Peroxynitrite mediated nitrosative stress, an indisputable initiator of DNA damage and overactivation of poly(ADP-ribose) polymerase (PARP), a nuclear enzyme activated after sensing DNA damage, are two crucial pathogenetic mechanisms in diabetic neuropathy. The intent of the present study was to investigate the effect of combination of a peroxynitrite decomposition catalyst (PDC), FeTMPyP and a PARP inhibitor, 4-ANI against diabetic peripheral neuropathy. The end points of evaluation of the study included motor nerve conduction velocity (MNCV) and nerve blood flow (NBF) for evaluating nerve functions; thermal hyperalgesia and mechanical allodynia for assessing nociceptive alterations, malondialdehyde and peroxynitrite levels to detect oxidative stress-nitrosative stress; NAD concentration in sciatic nerve to assess overactivation of PARP. Additionally immunohistochemical studies for nitrotyrosine and Poly(ADP-ribose) (PAR) was also performed. Treatment with the combination of FeTMPyP and 4-ANI led to significant improvement in nerve functions and pain parameters and also attenuated the oxidative-nitrosative stress markers. Further, the combination also reduced the overactivation of PARP as evident from increased NAD levels and decreased PAR immunopositivity in sciatic nerve microsections. Thus, it can be concluded that treatment with the combination of a PDC and PARP inhibitor attenuates alteration in peripheral nerves in diabetic neuropathy (DN).
authors.affiliation: Molecular Neuropharmacology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Sector-67, SAS Nagar, Punjab 160062, India.
authors.forename: Geeta
authors.initials: G
authors.lastname: Negi
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Kumar
authors.forename: Shyam S
authors.initials: SS
authors.lastname: Sharma
mesh_terms: D015057:1-Naphthylamine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000818:Animals; D004249:DNA Damage / Q000187:drug effects*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008665:Metalloporphyrins / Q000627:therapeutic use*; D053644:Naphthalimides / Q000627:therapeutic use*; D018384:Oxidative Stress / Q000187:drug effects; D010525:Peripheral Nerves / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D030421:Peroxynitrous Acid / Q000037:antagonists & inhibitors / Q000633:toxicity; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D015363:Quinolones / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: C492721:5,10,15,20-tetrakis(N-methyl-4'-pyridyl)porphyrinato-iron(III); D008665:Metalloporphyrins; D053644:Naphthalimides; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D015363:Quinolones; D030421:Peroxynitrous Acid; C086538:4-amino-1,8-naphthalimide; D015057:1-Naphthylamine