Effects of electroacupuncture on experimental periodontitis in rats.
BACKGROUND
Acupuncture has shown the capability of modulating the immuno-inflammatory response of the host. This study aims to evaluate the effects of electroacupuncture (EA) on ligature-induced periodontitis in rats.


METHODS
Thirty-two animals were divided into four groups: 1) control; 2) experimental periodontitis (EP); 3) sham-treated (EP/EA-sham); and 4) treated with EA (EP/EA). For the EP groups, a ligature was placed around the right mandibular first molars at day 1. Sessions of EA or EA-sham were assigned every other day. For EA treatment, large intestine meridian points LI4 and LI11 and stomach meridian points ST36 and ST44 were used. EA-sham was performed in off-meridian points. Animals were euthanized at day 11. Histomorphometric and microtomographic analyses were performed. Immunolabeling patterns for the receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP) were assessed. Expressions of interleukin (IL)-1β, matrix metalloproteinase (MMP)-8, IL-6, and cyclooxygenase (COX)-2 messenger RNAs (mRNAs) were evaluated by quantitative reverse transcription-polymerase chain reaction. Data were analyzed statistically (P <0.05, analysis of variance).


RESULTS
Histomorphometric and microtomographic analyses demonstrated that group EP/EA presented reduced alveolar bone loss when compared to group EP (P <0.05). Reduced RANKL immunolabeling and fewer TRAP-positive multinucleated cells were observed in the EA-treated group in relation to group EP. No differences were observed in OPG expression among groups. EA treatment decreased the genic expression of IL-1β and MMP-8 (P <0.05), increased the mRNA expression of IL-6 (P <0.05), and did not modify the genic expression of COX-2 in animals with EP (P >0.05).


CONCLUSIONS
It can be concluded that EA reduced periodontal tissue breakdown and the expression of some proinflammatory mediators and a proresorptive factor in EP in rats.
*Department of Clinical Dentistry, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Mario R P
MR
Lisboa
†Department of Morphology, Faculty of Medicine, Federal University of Ceará.
Delane V
DV
Gondim
‡Department of Basic Sciences, Division of Histology, Dental School of Aracatuba, São Paulo State University, Aracatuba, São Paulo, Brazil.
Edilson
E
Ervolino
§Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará.
Mariana L
ML
Vale
‖Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirao Preto School of Dentistry, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.
Nicolly P R
NP
Frota
*Department of Clinical Dentistry, Federal University of Ceará, Fortaleza, Ceará, Brazil.
Nara L T
NL
Nunes
¶Department of Veterinary Pathology, São Paulo State University, Jaboticabal, São Paulo, Brazil.
Viviane C
VC
Mariguela
‖Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirao Preto School of Dentistry, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.
Mario
M
Taba
‖Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirao Preto School of Dentistry, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.
Michel R
MR
Messora
‖Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirao Preto School of Dentistry, University of São Paulo, Ribeirao Preto, São Paulo, Brazil.
Flávia A C
FA
Furlaneto
D000135:Acid Phosphatase / Q000032:analysis; D015669:Acupuncture Points; D016301:Alveolar Bone Loss / Q000473:pathology / Q000628:therapy; D000818:Animals; D015519:Bone Density / Q000502:physiology; D051546:Cyclooxygenase 2 / Q000032:analysis; D015671:Electroacupuncture / Q000379:methods*; D015726:Giant Cells / Q000473:pathology; D007091:Image Processing, Computer-Assisted / Q000379:methods; D053583:Interleukin-1beta / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D020784:Matrix Metalloproteinase 8 / Q000032:analysis; D053244:Osteoprotegerin / Q000032:analysis; D010513:Periodontal Ligament / Q000737:chemistry / Q000473:pathology; D010518:Periodontitis / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D051381:Rats; D017208:Rats, Wistar; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000032:analysis; D000071681:Tartrate-Resistant Acid Phosphatase; D055114:X-Ray Microtomography / Q000379:methods
D053583:Interleukin-1beta; D015850:Interleukin-6; D007527:Isoenzymes; D053244:Osteoprotegerin; D053246:Receptor Activator of Nuclear Factor-kappa B; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D020784:Matrix Metalloproteinase 8
Bone resorption; electroacupuncture; inflammation mediators; periodontitis.