title: [Effects of tea polyphenols and tea pigments on cell cycle regulators in rat liver precancerous lesions].
abstract: OBJECTIVE
  This study is to investigate the effects of tea polyphenols and tea pigments on cell cycle regulators in rat liver precancerous lesions.
  
  
  METHODS
  The modified Solt-Farber precancerous liver rat model was used. Rats were given water, tea polypheol solution (0.1%) or tea pigment solution (0.1%) throughout the whole experiment (56 days). Cyclin D1, P21(WAF1/CIP1), GADD45 and PCNA protein expression were detected by Western blotting and the RT-PCR method was applied to study the expression of Cdk4.
  
  
  RESULTS
  Cyclin D1, Cdk4 and PCNA expressions were significantly inhibited, and the expression of P21(WAF1/CIP1) and GADD45 were significantly induced by tea polyphenols and tea pigments treatments.
  
  
  CONCLUSIONS
  Tea polyphenols and tea pigments induced cell cycle arrest and inhibited cell proliferation by regulating cell cycle regulators.
authors.affiliation: Institute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine, Beijing 100050, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Jia
authors.forename: Chi
authors.initials: C
authors.lastname: Han
authors.forename: Junshi
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D019938:Cyclin D1 / Q000187:drug effects / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000235:genetics; D016213:Cyclins / Q000187:drug effects / Q000378:metabolism; D005419:Flavonoids; D047908:Intracellular Signaling Peptides and Proteins; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D010636:Phenols / Q000494:pharmacology*; D010860:Pigments, Biological / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D059808:Polyphenols; D011230:Precancerous Conditions / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018809:Proliferating Cell Nuclear Antigen / Q000187:drug effects / Q000378:metabolism; D011506:Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013662:Tea / Q000737:chemistry*; D000097642:GADD45 Proteins
chemical_list: D018797:Cell Cycle Proteins; D019938:Cyclin D1; D051358:Cyclin-Dependent Kinase 4; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases; D016213:Cyclins; D005419:Flavonoids; D047908:Intracellular Signaling Peptides and Proteins; D010636:Phenols; D010860:Pigments, Biological; D011108:Polymers; D059808:Polyphenols; D018809:Proliferating Cell Nuclear Antigen; D011506:Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D013662:Tea; D000097642:GADD45 Proteins; C493958:Cdkn1a protein, rat; C495903:Cdk4 protein, rat