title: Synergistic effects of green tea polyphenols and alphacalcidol on chronic inflammation-induced bone loss in female rats.
abstract: Studies suggest that green tea polyphenols (GTP) or alphacalcidol is promising agent for preventing bone loss. Findings that GTP supplementation plus alphacalcidol administration increased bone mass via a decrease of oxidative stress and inflammation suggest a significant role of GTP plus alphacalcidol in bone health of patients with chronic inflammation.
  
  
  BACKGROUND
  Studies have suggested that green tea polyphenols (GTP) or alphacalcidol are promising dietary supplements for preventing bone loss in women. However, the mechanism(s) related to the possible osteo-protective role of GTP plus D(3) in chronic inflammation-induced bone loss is not well understood.
  
  
  METHODS
  This study evaluated bioavailability, efficacy, and related mechanisms of GTP in combination with alphacalcidol in conserving bone loss in rats with chronic inflammation. A 12-week study of 2 (no GTP vs. 0.5% GTP in drinking water) × 2 (no alphacalcidol vs. 0.05 μg/kg alphacalcidol, 5×/week) factorial design in lipopolysaccharide-administered female rats was performed. In addition, a group receiving placebo administration was used to compare with a group receiving lipopolysaccharide administration only to evaluate the effect of lipopolysaccharide.
  
  
  RESULTS
  Lipopolysaccharide administration resulted in lower values for bone mass, but higher values for serum tartrate-resistant acid phosphatase (TRAP), urinary 8-hydroxy-2'-deoxyguanosine, and mRNA expression of tumor necrosis factor-α and cyclooxygenase-2 in spleen. GTP supplementation increased urinary epigallocatechin and epicatechin concentrations. Both GTP supplementation and alphacalcidol administration resulted in a significant increase in bone mass, but a significant decrease in serum TRAP levels, urinary 8-hydroxydeoxyguanosine levels, and mRNA expression of tumor necrosis factor-α and cyclooxygenase-2 in spleen. A synergistic effect of GTP and alphacalcidol was observed in these parameters. Neither GTP nor alphacalcidol affected femoral bone area or serum osteocalcin.
  
  
  CONCLUSIONS
  We conclude that a bone-protective role of GTP plus alphacalcidol during chronic inflammation bone loss may be due to a reduction of oxidative stress damage and inflammation.
authors.affiliation: Department of Pathology, Texas Tech University Health Sciences Center, BB 198, 3601 4th street, Lubbock, TX 79430-9097, USA. leslie.shen@ttuhsc.edu
authors.forename: C-L
authors.initials: CL
authors.lastname: Shen
authors.forename: J K
authors.initials: JK
authors.lastname: Yeh
authors.forename: J J
authors.initials: JJ
authors.lastname: Cao
authors.forename: O L
authors.initials: OL
authors.lastname: Tatum
authors.forename: R Y
authors.initials: RY
authors.lastname: Dagda
authors.forename: J-S
authors.initials: JS
authors.lastname: Wang
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000627:therapeutic use / Q000652:urine; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D004326:Drinking; D004353:Drug Evaluation, Preclinical / Q000379:methods; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005260:Female; D005419:Flavonoids / Q000627:therapeutic use* / Q000652:urine; D015870:Gene Expression; D006887:Hydroxycholecalciferols / Q000627:therapeutic use* / Q000652:urine; D007249:Inflammation / Q000150:complications*; D008070:Lipopolysaccharides; D010636:Phenols / Q000627:therapeutic use* / Q000652:urine; D008517:Phytotherapy / Q000379:methods*; D010936:Plant Extracts / Q000627:therapeutic use / Q000652:urine; D059808:Polyphenols; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D013154:Spleen / Q000378:metabolism; D013662:Tea; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D005419:Flavonoids; D006887:Hydroxycholecalciferols; D008070:Lipopolysaccharides; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D012333:RNA, Messenger; D013662:Tea; D014409:Tumor Necrosis Factor-alpha; D000080242:8-Hydroxy-2'-Deoxyguanosine; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; D003849:Deoxyguanosine; C008088:alfacalcidol