title: Anti-inflammatory activity of green versus black tea aqueous extract in a rat model of human rheumatoid arthritis.
abstract: OBJECTIVE
  Recently, there has been an increasing interest in tea (Camellia sinensis) as a protective agent against inflammatory diseases. Here, we evaluated/compared the anti-inflammatory activity of two different doses (0.5 and 1.0 g/kg body weight) of green tea aqueous extract (GTE, rich in catechins) and black tea aqueous extract (BTE, rich in theaflavins and thearubigins) in rat adjuvant-induced arthritis (AIA).
  
  
  METHODS
  Adjuvant-induced arthritis rat model received orally/daily distilled water as vehicle, indomethacin (1.0 mg/kg body weight; a non-steroidal/anti-inflammatory drug), or tea aqueous extracts (for 28 or 14 consecutive days starting from day 0 or 14 of arthritis induction, respectively).
  
  
  RESULTS
  The present study showed that only the high dose of GTE (from day 0) significantly alleviated (P < 0.05-0.001) all complications shown in arthritic rats, including synovial joint inflammation, elevation in erythrocyte sedimentation rate, blood leukocytosis (due to lymphocytosis and neutrocytosis), and changes in weight/cellularity of lymphoid organs. The anti-arthritic activity of the high dose of GTE (from day 0) was comparable (P > 0.05) with that of indomethacin (12.9-53.8 vs. 9.5-48.4%, respectively) and mediated by significantly decreasing and down-regulating (P < 0.001) the systemic production of pro-inflammatory cytokines and the expression of chemokine receptor-5 in synovial tissues, respectively. Moreover, the anti-arthritic activity of tea aqueous extracts was in the following order: high dose of GTE > low dose of GTE ≥ high dose of BTE > low dose of BTE.
  
  
  CONCLUSIONS
  The present study proved the anti-inflammatory activity of GTE over BTE and equal to that of indomethacin in AIA rat model.
authors.affiliation: Zoology Department, Faculty of Science, Ain Shams University, Cairo, Egypt.
authors.forename: Gamal
authors.initials: G
authors.lastname: Ramadan
authors.affiliation: Zoology Department, Faculty of Science, Ain Shams University, Cairo, Egypt.
authors.forename: Nadia M
authors.initials: NM
authors.lastname: El-Beih
authors.affiliation: Molecular Biology Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), Sadat City University, Sadat City, Egypt.
authors.forename: Roba M
authors.initials: RM
authors.lastname: Talaat
authors.affiliation: Zoology Department, Faculty of Science, Ain Shams University, Cairo, Egypt.
authors.forename: Eman A
authors.initials: EA
authors.lastname: Abd El-Ghffar
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D018501:Antirheumatic Agents / Q000494:pharmacology*; D001169:Arthritis, Experimental / Q000097:blood / Q000139:chemically induced / Q000276:immunology / Q000517:prevention & control*; D001799:Blood Sedimentation; D028241:Camellia sinensis; D016207:Cytokines / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000139:chemically induced / Q000517:prevention & control; D005620:Freund's Adjuvant; D007213:Indomethacin / Q000494:pharmacology; D018836:Inflammation Mediators / Q000097:blood; D007596:Joints / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D008297:Male; D008517:Phytotherapy; D010946:Plants, Medicinal; D017208:Rats, Wistar; D019713:Receptors, CCR5 / Q000378:metabolism; D013583:Synovial Membrane / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D013662:Tea; D013997:Time Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D018501:Antirheumatic Agents; D016207:Cytokines; D018836:Inflammation Mediators; D019713:Receptors, CCR5; D013662:Tea; D005620:Freund's Adjuvant; D007213:Indomethacin
keywords: CCR5 and pro-inflammatory cytokines; anti-inflammatory activity; green and black tea; indomethacin; rat adjuvant-induced arthritis