Tea Polyphenols Inhibit Rat Osteoclast Formation and Differentiation

Abstract

Abstract. Matrix metalloproteinases (MMPs) play an important role in degeneration of the matrix associated with bone and cartilage. Regulation of osteoclast activity is essential in the treatment of bone disease, including osteoporosis and rheumatoid arthritis. Polyphenols in green tea, particularly epigallocatechin-3-gallate (EGCG), inhibit MMPs expression and activity. However, the effects of the black tea polyphenol, theaflavin-3,3′-digallate (TFDG), on osteoclast and MMP activity are unknown. Therefore, we examined whether TFDG and EGCG affect MMP activity and osteoclast formation and differentiation in vitro. TFDG or EGCG (10 and 100 μM) was added to cultures of rat osteoclast precursors cells and mature osteoclasts. Numbers of multinucleated osteoclasts and actin rings decreased in polyphenol-treated cultures relative to control cultures. MMP-2 and MMP-9 activities were lower in TFDG-and EGCG-treated rat osteoclast precursor cells than in control cultures. MMP-9 mRNA levels declined significantly in TFDG-treated osteoclasts in comparison to control osteoclasts. TFDG and EGCG inhibited the formation and differentiation of osteoclasts via inhibition of MMPs. TFDG may suppress actin ring formation more effectively than EGCG. Thus, TFDG and EGCG may be suitable agents or lead compounds for the treatment of bone resorption diseases.

Camellia Sinensis Modulates Telomerase in Collagen-Induced Arthritis

“…In our findings, a reduction in the clinical scores of joint inflammation and joint erosion were in agreement with the result of trial in which the green tea polyphenol epigallocatechin-3-gallateas a potent antioxidant improves autoimmune arthritis by both regulation of TH17 regulatory cells and inhibition of osteoclasts development [17]. Moreover, there is more evidence that polyphenols in green tea, particularly EGCG, inhibit matrix metalloproteinase activity which plays a fundamental role in pathogenesis of many diseases such as RA [18]. Although, joint erosion in CSS-fed animals reduced, the level of significance in the radiological index of the joints in treated rats compared to control could not be achieved.…”

Celastrus and Its Bioactive Celastrol Protect against Bone Damage in Autoimmune Arthritis by Modulating Osteoimmune Cross-talk

“…Epigallocatechin gallate, a bioactive component of green tea, has been reported to inhibit IL-6, a critical proinflammatory cytokine involved in inflammation and bone damage in arthritis (52). Epigallocatechin gallate has also been shown to inhibit the formation and differentiation of osteoclasts via inhibition of MMPs (53). In another study, curcumin (from turmeric) was shown to inhibit overiectomy-induced bone loss by reducing osteoclastogenesis and impaired RANKL signaling (54).…”

Biological Activities and Possible Dental Application of Three Major Groups of Polyphenols

“…These pilot clinical studies suggest the therapeutic potentiality of SE against oral diseases (114). Tea polyphenols such as epigallocatechin-3-gallate and theaflavin-3,3′-digallate also inhibited the osteoclast formation and differentiation in vitro (115).…”