Green tea polyphenols mitigate bone loss of female rats in a chronic inflammation-induced bone loss model☆☆☆

Green tea polyphenols attenuate deterioration of bone microarchitecture in female rats with systemic chronic inflammation

“…The placebo rats also had free access to no GTP (P group) or 0.5% GTP drinking water (PG group) throughout the study period. The 0.5% concentration of GTP in drinking water daily mimics human consumption of green tea of 4 cups a day based on our previous human [20] and animal studies [15,21]. All rats were fed a rodent chow diet ad libitum during the 12-week feeding period.…”

“…The most widely recognized properties of green tea are their antioxidant activities, arising from their ability to scavenge reactive oxygen species [17]. Our recent study demonstrated a protective action of green tea polyphenols (GTP, green tea extract) against chronic inflammationinduced bone loss in female rats through reducing oxidative stress [15]. However, no data are available showing an impact of GTP on bone quality and microachitecture of rats with chronic inflammation.…”

“…Oxidative stress resulting from excessive production of reactive oxygen species perturbs the normal redox balance of osteogenesis including bone formation and resorption. Recently, Shen et al [15] demonstrated that oxidative stress, as shown by an increase in urinary excretion of 8-hydroxydeoxyguanosine (an oxidative stress biomarker), is involved in the pathogenesis of bone loss in female rats due to chronic inflammation. Oxidative stress results in (1) an increase in osteoblast and osteocyte apoptosis [11], (2) a decrease in osteoblast number via extracellular signal-regulated kinases (ERK) and ERK-dependent nuclear factor-κB signaling pathways [12], (3) a decrease in the rate of bone formation via Wnt/ β-catenin signaling [13], and (4) an increase in the differentiation and function of osteoclasts [14].…”

The Potential Role of Quercus Infectoria Gall Extract on Osteoblast Function and Bone Metabolism

“…They conclude that dietary supplementation with GTE appears to be an effective and simple way to counter high reactive oxygen species (ROS) level due to cigarette smoke. In addition to that, supplementation with green tea polyphenols (GTF) in female rats resulted in higher values of bone formation indicators [femoral bone mineral content (BMC), BMD and serum OCN], but lower the values of bone resoprtion indicators [serum tartrate-resistant acid phosphate (TRAP), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and cyclooxygenase-2 (COX-2) levels] [71].…”

Green tea polyphenols avert chronic inflammation-induced myocardial fibrosis of female rats

“…Throughout the study period, the placebo rats also had free access to no GTP (P group) or 0.5% GTP drinking water (PG group). The 0.5% concentration (wt/vol) of GTP in drinking water daily mimics human consumption of green tea at 4 cups a day based on our previous human [12] and animal studies [13,14]. All rats were fed a rodent chow diet ad libitum during the study period.…”