Effect of Black Tea Extract and Thearubigins on Osteoporosis in Rats and Osteoclast Formation in vitro.

Qingqing Liang,Ming Lv,Ying Wu,Jun Sheng,Xiaojuan Zhang,Yewei Huang,Xuanjun Wang,Jun Hu

doi:10.3389/fphys.2018.01225

Qingqing Liang, Ming Lv + Show 6 more

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https://doi.org/10.3389/fphys.2018.01225

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Abstract

Background: Osteoporosis is a major health problem that is closely related to substantial morbidity, mortality and decline in life quality for the aging population. Although previous studies and epidemiological evidence have demonstrated an association between black tea consumption and the prevention of bone loss, the underlying mechanism remains unclear. So, the effect of black tea extract (BTE) and thearubigins (TRs) on osteoporosis in rats and osteoclast formation in vitro were investigated.Methods: In vivo, ovariectomized (OVX) rats were used to establish osteoporosis models. To validate the model and study the effects of BTE and TRs on osteoporosis, the female Wistar rats were divided into a sham-operated group and five OVX groups including model, Xian-Ling-Gu-Bao (XLGB) (as a positive control), BTE, TRs low-dose, and TRs high-dose group. The rats in the four treatment groups were given the corresponding test sample for 12 weeks. Then, the body weight, femur indices, and serum biomarkers were examined and analyzed. In vitro, RAW264.7 murine macrophages were used as model of osteoclast formation. The effects of BTE and TRs on osteoclasts formation and the specific genes and protein levels of osteoclasts were determined.Results: Although there was no significant effect on the OVX-induced body weight gain by BTE or TRs, the levels of maximum bending force, cortical bone thickness and biomarker of bone resorption (acid phosphatase) can be significantly ameliorated by BTE or TRs in OVX rats. Furthermore, both of BTE and TRs can inhibit the osteoclastogenesis and diminish the expression levels of the related genes and proteins.

Highlights

Osteoporosis is a major health problem affecting the elderly (Shen et al, 2009b) with an increasing prevalence worldwide owing to the aging population, and its diagnosis and treatment remain challenging (Maeda and Lazaretti-Castro, 2014)
The content of TRs was determined by spectrophotometer (Roberts and Smith, 1963; Owuor and Obanda, 1995), caffeine and three kinds of TFs (TF, TF-3, and TF-3,3 ) were determined by high performance liquid chromatograph (HPLC) (Wang et al, 2004; Zhu et al, 2017) (Supplementary Figures 1, 2)
To verify the role of black tea extract (BTE) and TRs in ameliorating osteoporosis, an experimental model of osteoporosis was established in female rats by the surgical removal of both ovaries

Summary

Introduction

Osteoporosis is a major health problem affecting the elderly (Shen et al, 2009b) with an increasing prevalence worldwide owing to the aging population, and its diagnosis and treatment remain challenging (Maeda and Lazaretti-Castro, 2014). BTE and TRs Improve Osteoporosis to increased bone fragility and a higher risk of fracture (Shen et al, 2009b; Rachner et al, 2011; Sacco et al, 2013), and is associated with substantial morbidity, mortality, and decline in quality of life (Maeda and Lazaretti-Castro, 2014). Anabolic agents include strontium ranelate (only available in Europe) and teriparatide (Tsai et al, 2013; Zhang et al, 2015) These pharmacological interventions are generally complicated by undesirable side effects such as hypercalcemia, joint pain, gastrointestinal intolerance, urinary or respiratory tract infections, increased risk of malignancy, and excessive suppression of bone turnover (Bolland et al, 2010, 2011; Tella and Gallagher, 2014). The effect of black tea extract (BTE) and thearubigins (TRs) on osteoporosis in rats and osteoclast formation in vitro were investigated

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