title: Protective effect of melatonin against the inflammatory response elicited by crude venom from isolated nematocysts of Pelagia noctiluca (Cnidaria, Scyphozoa).
abstract: Melatonin (N-acetyl-5-methoxytryptamine) is an efficient free radical scavenger and antioxidant, both in vitro and in vivo. The role of melatonin as an immunomodulator is, in some cases, contradictory. In this study we have investigated the therapeutic efficacy of melatonin in rats subjected to Pelagia noctiluca crude venom (of the familia Pelaguiidae; and genus Pelagia) induced acute paw inflammation. In particular, injection of the venom into the paw of rats elicited an acute inflammatory response characterized by accumulation of fluid containing a large number of polymorphonuclear neutrophils in the paw and subsequent lipid peroxidation. Furthermore, the venom promoted an expression of iNOS, nitrotyrosine and the activation of the nuclear enzyme poly (ADP-ribose) polymerase as determined by immunohistochemical analysis of paw tissues. Administration of melatonin 30 min, 1 and 6 hr after the challenge with the venom, caused a significant reduction in all the parameters of inflammation measured. Thus, based on these findings we propose that melatonin may be useful a treatment of local acute inflammation induced by P. noctiluca crude venom.
authors.affiliation: Department of Life Sciences M. Malpighi, Section of General Physiology and Pharmacology, University of Messina, Messina, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Marino
authors.forename: Rosanna
authors.initials: R
authors.lastname: Di Paola
authors.forename: Concetta
authors.initials: C
authors.lastname: Crisafulli
authors.forename: Emanuela
authors.initials: E
authors.lastname: Mazzon
authors.forename: Rossana
authors.initials: R
authors.lastname: Morabito
authors.forename: Irene
authors.initials: I
authors.lastname: Paterniti
authors.forename: Maria
authors.initials: M
authors.lastname: Galuppo
authors.forename: Tiziana
authors.initials: T
authors.lastname: Genovese
authors.forename: Giuseppina
authors.initials: G
authors.lastname: La Spada
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cuzzocrea
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053818:Chymases / Q000378:metabolism; D003064:Cnidarian Venoms / Q000633:toxicity*; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology; D006651:Histocytochemistry; D020672:I-kappa B Proteins / Q000378:metabolism; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D000072000:NF-KappaB Inhibitor alpha; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D009195:Peroxidase / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D037401:Scyphozoa / Q000737:chemistry*; D051996:Transcription Factor RelA / Q000378:metabolism; D053802:Tryptases / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D003064:Cnidarian Venoms; D020672:I-kappa B Proteins; C000606206:Nfkbia protein, rat; D020011:Protective Agents; D051996:Transcription Factor RelA; D000072000:NF-KappaB Inhibitor alpha; D009195:Peroxidase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D053818:Chymases; D053802:Tryptases; D008550:Melatonin