title: The effect of epigallocatechin-3-gallate (EGCG) on human alveolar bone cells both in vitro and in vivo.
abstract: OBJECTIVE
  The effects of epigallocatechin-3-gallate (EGCG), a major catechin in green tea, on human and mouse osteoblasts remain controversial. This study investigated the direct effects of EGCG on human alveolar bone-derived cells (hABCs) both in vitro and in vivo.
  
  
  METHODS
  hABCs which were collected from eight children (aged 7-9 years, seven males and one female) were treated with EGCG at various concentrations (1, 5, 10, 25, and 50μM), and a proliferation assay, flow cytometric analysis for apoptosis evaluation, migration assay, and in vitro osteogenic differentiation were performed. hABCs that were pretreated with 10μM EGCG and mixed with calcium phosphate carrier combined with EGCG (0.1, 0.5, or 1.5mg) in vivo were transplanted into immunodeficient mouse. Histological staining, quantitative gene expressions, and alkaline phosphatase activity were evaluated in the retrieved transplants.
  
  
  RESULTS
  The proliferation and migration were decreased when EGCG was present at over 25μM. The osteogenic differentiation increased slightly when EGCG was present at up to 10μM, and clearly decreased for higher concentrations of EGCG. In vivo, the potential for hard-tissue formation was slightly higher for the group with 0.1mg of EGCG than for the control group, and decreased sharply for higher concentrations of EGCG.
  
  
  CONCLUSIONS
  The present observations suggest that EGCG at a low concentration can slightly enhance the osteogenic effect in vivo, whereas at a higher concentration it can prevent the osteogenic differentiation of hABCs both in vitro and in vivo.
authors.affiliation: Division of Pediatric Dentistry, Department of Dentistry, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea.
authors.forename: Yon-Joo
authors.initials: YJ
authors.lastname: Mah
authors.affiliation: Department of Pediatric Dentistry, College of Dentistry, Yonsei University, Seoul, Republic of Korea; Department of Pediatric Dentistry, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Je Seon
authors.initials: JS
authors.lastname: Song
authors.affiliation: Department of Pediatric Dentistry, College of Dentistry, Yonsei University, Seoul, Republic of Korea; Department of Pediatric Dentistry, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Seong-Oh
authors.initials: SO
authors.lastname: Kim
authors.affiliation: Department of Pediatric Dentistry, College of Dentistry, Yonsei University, Seoul, Republic of Korea; Department of Pediatric Dentistry, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Pediatric Dentistry, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Mijeong
authors.initials: M
authors.lastname: Jeon
authors.affiliation: Department of Periodontology, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
authors.affiliation: Division in Pharmacology, Department of Oral Biology, College of Dentistry, Yonsei University, Republic of Korea.
authors.forename: Seok Jun
authors.initials: SJ
authors.lastname: Moon
authors.affiliation: Department of Oral Biochemistry, Institute of Oral Biology, College of Dentistry, Kyung-Hee University, Republic of Korea.
authors.forename: Jeong-Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Pediatric Dentistry, College of Dentistry, Yonsei University, Seoul, Republic of Korea; Department of Pediatric Dentistry, Oral Science Research Center, College of Dentistry, Yonsei University, Seoul, Republic of Korea. Electronic address: magic4melody@gmail.com.
authors.forename: Hyung-Jun
authors.initials: HJ
authors.lastname: Choi
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000539:Alveolar Process / Q000166:cytology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002130:Calcium Phosphates / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002648:Child; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D010012:Osteogenesis / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002130:Calcium Phosphates; D002392:Catechin; C020243:calcium phosphate; C045651:epigallocatechin gallate; D000469:Alkaline Phosphatase
keywords: Alveolar bone-derived cells; Epigallocatechin-3-gallate (EGCG); In vivo transplantation; Osteogenic differentiation