Anti-allodynic property of flavonoid myricitrin in models of persistent inflammatory and neuropathic pain in mice.
The aim of the present study was to investigate the effects of myricitrin, a flavonoid with anti-inflammatory and antinociceptive action, upon persistent neuropathic and inflammatory pain. The neuropathic pain was caused by a partial ligation (2/3) of the sciatic nerve and the inflammatory pain was induced by an intraplantar (i.pl.) injection of 20 microL of complete Freund's adjuvant (CFA) in adult Swiss mice (25-35 g). Seven days after sciatic nerve constriction and 24 h after CFA i.pl. injection, mouse pain threshold was evaluated through tactile allodynia, using Von Frey Hair (VFH) filaments. Further analyses performed in CFA-injected mice were paw edema measurement, leukocytes infiltration, morphological changes and myeloperoxidase (MPO) enzyme activity. The intraperitoneal (i.p.) treatment with myricitrin (30 mg/kg) significantly decreased the paw withdrawal response in persistent neuropathic and inflammatory pain and decreased mouse paw edema. CFA injection increased 4-fold MPO activity and 27-fold the number of neutrophils in the mouse paw after 24 h. Myricitrin strongly reduced MPO activity, returning to basal levels; however, it did not reduce neutrophils migration. In addition, myricitrin treatment decreased morphological alterations to the epidermis and dermis papilar of mouse paw. Together these results indicate that myricitrin produces pronounced anti-allodynic and anti-edematogenic effects in two models of chronic pain in mice. Considering that few drugs are currently available for the treatment of chronic pain, the present results indicate that myricitrin might be potentially interesting in the development of new clinically relevant drugs for the management of this disorder.
Meotti
Flavia Carla
FC
Departamento de Química, Universidade Federal de Santa Maria, 97110-000 Santa Maria, RS, Brazil.
Missau
Fabiana Cristina
FC
Ferreira
Juliano
J
Pizzolatti
Moacir Geraldo
MG
Mizuzaki
Cristina
C
Nogueira
Cristina Wayne
CW
Santos
Adair R S
AR
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004487:Edema / Q000188:drug therapy / Q000473:pathology; D005260:Female; D005419:Flavonoids / Q000627:therapeutic use*; D005620:Freund's Adjuvant; D007249:Inflammation / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D020556:Neutrophil Infiltration / Q000187:drug effects; D010146:Pain / Q000188:drug therapy* / Q000473:pathology; D017288:Pain Threshold / Q000187:drug effects; D020426:Sciatic Neuropathy / Q000188:drug therapy* / Q000473:pathology; D040521:Subcutaneous Tissue / Q000187:drug effects / Q000473:pathology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D005419:Flavonoids; C008577:myricitrin; D005620:Freund's Adjuvant