title: Genistein, a natural phytoestrogen from soy, relieves neuropathic pain following chronic constriction sciatic nerve injury in mice: anti-inflammatory and antioxidant activity.
abstract: There is great interest in soy isoflavones as alternatives to endogenous estrogens not only in hormonal pathologies, but also in inflammatory, neurodegenerative diseases, and pain. We investigated the effect of the isoflavone genistein on neuropathic pain. Genistein binds estrogen receptors (ER) with higher affinity for the ERbeta particularly expressed in neuronal and immune cells. Neuropathy was induced in mice by means of chronic sciatic nerve constriction, and the subcutaneous administration of genistein from the third day after the lesion reversed pain hypersensitivity in a time- and dose-dependent manner. This effect may have been due to the activation of classical nuclear receptor and/or anti-oxidant, anti-inflammatory, and immunomodulating properties of genistein. The fact that a specific ERbeta antagonist prevented both its anti-allodynic and anti-hyperalgesic action, whereas a specific ERalpha antagonist was ineffective and a non-selective ER antagonist only reversed the anti-allodynic effect, suggests the involvement of ERbeta. Antioxidant effects are also involved as the anti-nociceptive dose reversed the increase in reactive oxygen species and malondialdehyde in injured paw tissues, and increased the activity of anti-oxidant enzymes. The phytoestrogen had immunomodulatory and anti-inflammatory activities as it reduced peripheral and central nuclear factor-kappaB, nitric oxide system and pro-inflammatory cytokine over-activation. Taken together, our results suggest that genistein could ameliorate painful neuropathy by multiple mechanisms.
authors.affiliation: Department of Pharmacology, Chemotherapy and Medical Toxicology, University of Milan, Milan, Italy.
authors.forename: Anna Elisa
authors.initials: AE
authors.lastname: Valsecchi
authors.forename: Silvia
authors.initials: S
authors.lastname: Franchi
authors.forename: Alberto Emilio
authors.initials: AE
authors.lastname: Panerai
authors.forename: Paola
authors.initials: P
authors.lastname: Sacerdote
authors.forename: Anna Elisa
authors.initials: AE
authors.lastname: Trovato
authors.forename: Mariapia
authors.initials: M
authors.lastname: Colleoni
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use; D002908:Chronic Disease / Q000188:drug therapy; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D019833:Genistein / Q000494:pharmacology* / Q000627:therapeutic use; D006930:Hyperalgesia / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D007249:Inflammation / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors / Q000378:metabolism; D008026:Ligation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009475:Neurons, Afferent / Q000187:drug effects / Q000378:metabolism; D009619:Nociceptors / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D048789:Phytoestrogens / Q000494:pharmacology / Q000627:therapeutic use; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism; D020426:Sciatic Neuropathy / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D013025:Glycine max / Q000737:chemistry; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D018836:Inflammation Mediators; D048789:Phytoestrogens; D010936:Plant Extracts; D011960:Receptors, Estrogen; D019833:Genistein