Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, 79430, USA.
Calcif Tissue Int. 2011 Jun;88(6):455-63. doi: 10.1007/s00223-011-9477-1. Epub 2011 Mar 23.
Recent studies show that green tea polyphenols (GTPs) attenuate bone loss and microstructure deterioration in ovariectomized aged female rats, a model of postmenopausal osteoporosis. This study evaluated the efficacy of GTPs at mitigating bone loss and microstructure deterioration along with related mechanisms in androgen-deficient aged rats, a model of male osteoporosis. A 2 (sham vs. orchidectomy) × 2 (no GTP and 0.5% GTP in drinking water) factorial design was studied for 16 weeks using 40 aged male rats. An additional 10 rats (baseline group) were killed at the beginning of study to provide baseline parameters. There was no difference in femoral mineral density between baseline and the sham only group. Orchidectomy suppressed serum testosterone and tartrate-resistant acid phosphatase concentrations, liver glutathione peroxidase activity, bone mineral density, and bone strength. Orchidectomy also decreased trabecular bone volume, number, and thickness in the distal femur and proximal tibia and bone-formation rate in trabecular bone of proximal tibia but increased serum osteocalcin concentrations and bone-formation rates in the endocortical tibial shaft. GTP supplementation resulted in increased serum osteocalcin concentrations, bone mineral density, and trabecular volume, number, and strength of femur; increased trabecular volume and thickness and bone formation in both the proximal tibia and periosteal tibial shaft; decreased eroded surface in the proximal tibia and endocortical tibial shaft; and increased liver glutathione peroxidase activity. We conclude that GTP supplementation attenuates trabecular and cortical bone loss through increasing bone formation while suppressing bone resorption due to its antioxidant capacity.
最近的研究表明，绿茶多酚（GTPs）可减轻去卵巢老龄雌性大鼠（绝经后骨质疏松症模型）的骨丢失和微结构恶化。本研究评估了 GTP 在缓解去势老龄大鼠（男性骨质疏松症模型）的骨丢失和微结构恶化方面的功效，以及相关机制。采用 40 只老龄雄性大鼠进行了 2（假手术 vs. 去势）×2（无 GTP 和 0.5% GTP 饮用水）析因设计，研究时间为 16 周。另外 10 只大鼠（基线组）在研究开始时处死，以提供基线参数。股骨矿物质密度在基线和仅假手术组之间没有差异。去势抑制了血清睾酮和抗酒石酸酸性磷酸酶浓度、肝谷胱甘肽过氧化物酶活性、骨矿物质密度和骨强度。去势还降低了远端股骨和近端胫骨的小梁骨体积、数量和厚度以及近端胫骨小梁的骨形成率，但增加了血清骨钙素浓度和皮质内胫骨干的骨形成率。GTP 补充剂导致血清骨钙素浓度、骨矿物质密度和股骨小梁体积、数量和强度增加；增加了近端胫骨和骨膜胫骨干的小梁体积和厚度以及骨形成；减少了近端胫骨和皮质内胫骨干的侵蚀表面；并增加了肝谷胱甘肽过氧化物酶活性。我们的结论是，GTP 补充剂通过增加骨形成而抑制骨吸收，从而减轻小梁骨和皮质骨的丢失，这与其抗氧化能力有关。
