title: Effect of avocado/soybean unsaponifiables on ligature-induced bone loss and bone repair after ligature removal in rats.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of administration of avocado/soybean unsaponifiable (ASU), a drug that is commonly used in the treatment of rheumatoid arthritis, on ligature-induced bone loss and bone repair after ligature removal in rats.
  
  
  METHODS
  Eighty-four rats were randomly assigned to four groups of equal size and received a daily gavage of either sterile saline [control (CTR)] or ASU (0.6 mg/kg), starting 7 d before (ASU/-7), on the day of (ASU/0) or 7 d after (ASU/+7) periodontitis induction. Periodontitis was induced by placing silk ligatures into the gingival sulcus of the second maxillary molars for 7 d; after 7 d, the ligatures were removed. Seven rats from each group were sacrificed, 7, 15 or 30 d after ligature removal. Bone resorption was evaluated by histomorphometry and micro-computed tomography (micro-CT). Immunohistochemistry was used to evaluate the expression of TRAP, RANKL and alkaline phosphatase (ALP), and quantitative PCR (qPCR) was used to evaluate the levels of interleukin-1beta (Il1β), tumor necrosis factor alpha (Tnfα), interleukin-6 (Il-6), Rankl and Alp. Statistical analysis was performed using the Shapiro-Wilk test, ANOVA and Tukey's test for normal data, and using the Kruskall-Wallis and Dunnet's tests for non-normal data (p < 0.05).
  
  
  RESULTS
  Histomorphometry and micro-CT analysis showed greater bone resorption in the CTR group than in the ASU/0 (15 d) and ASU/+7 (7 and 15 d) groups. The CTR group also presented with a higher expression of TRAP (15 and 30 d) and RANKL (7 and 15 d) compared with ASU/0 and ASU/+7 groups. Similarly, qPCR analysis showed higher levels of Rankl and Il1β mRNAs, and lower levels of Alp mRNA, in the CTR group compared with all other groups (for all periods).
  
  
  CONCLUSIONS
  ASU exhibited a positive effect on bone repair following ligature-induced periodontitis in rats.
authors.affiliation: Section of Periodontology, Department of Diagnosis and Surgery, Araraquara School of Dentistry, University Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: G J P L
authors.initials: GJ
authors.lastname: Oliveira
authors.affiliation: Section of Periodontology, Department of Diagnosis and Surgery, Araraquara School of Dentistry, University Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: L G F
authors.initials: LG
authors.lastname: Paula
authors.affiliation: Section of Periodontology, Department of Diagnosis and Surgery, Araraquara School of Dentistry, University Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: J A C
authors.identifier: http://orcid.org/0000-0002-8053-2407
authors.initials: JA
authors.lastname: Souza
authors.affiliation: Section of Oral Radiology, Department of Dentistry, Aarhus University, Aarhus, Denmark.
authors.forename: R
authors.initials: R
authors.lastname: Spin-Neto
authors.affiliation: Department of Periodontology, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Stavropoulos
authors.affiliation: Section of Periodontology, Department of Diagnosis and Surgery, Araraquara School of Dentistry, University Estadual Paulista - UNESP, Araraquara, SP, Brazil.
authors.forename: R A C
authors.initials: RA
authors.lastname: Marcantonio
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D016301:Alveolar Bone Loss / Q000188:drug therapy* / Q000473:pathology*; D000818:Animals; D001172:Arthritis, Rheumatoid / Q000188:drug therapy; D015870:Gene Expression; D005881:Gingiva / Q000473:pathology; D007150:Immunohistochemistry; D053583:Interleukin-1beta / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D008026:Ligation; D008297:Male; D008437:Maxilla; D008963:Molar; D010518:Periodontitis / Q000473:pathology; D027421:Persea / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D053245:RANK Ligand / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D047011:Silk; D013025:Glycine max / Q000737:chemistry*; D000071681:Tartrate-Resistant Acid Phosphatase / Q000032:analysis; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D010936:Plant Extracts; D053245:RANK Ligand; D047011:Silk; D014409:Tumor Necrosis Factor-alpha; D000469:Alkaline Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase
keywords: animal studies; avocado/soybean unsaponifiables; host modulation; periodontitis