Green Tea Catechin (-)-Epigallocatechin-3-Gallate (EGCG) Facilitates Fracture Healing

Abstract

Green tea drinking can ameliorate postmenopausal osteoporosis by increasing the bone mineral density. (-)-Epigallocatechin-3-gallate (EGCG), the abundant and active compound of tea catechin, was proven to be able to reduce bone loss and ameliorate microarchitecture in female ovariectomized rats. EGCG can also enhance the osteogenic differentiation of murine bone marrow mesenchymal stem cells and inhibit the osteoclastogenesis in RAW264.7 cells by modulation of the receptor activator of nuclear factor-kB (RANK)/RANK ligand (RANKL)/osteoprotegrin (OPG) (RANK/RANKL/OPG) pathway. Our previous study also found that EGCG can promote bone defect healing in the distal femur partially via bone morphogenetic protein-2 (BMP-2). Considering the osteoinduction property of BMP-2, we hypothesized that EGCG could accelerate the bone healing process with an increased expression of BMP-2. In this manuscript, we studied whether the local use of EGCG can facilitate tibial fracture healing. Fifty-six 4-month-old rats were randomly assigned to two groups after being weight-matched: a control group with vehicle treatment (Ctrl) and a study group with 10 µmol/L, 40 µL, EGCG treatment (EGCG). Two days after the operation, the rats were treated daily with EGCG or vehicle by percutaneous local injection for 2 weeks. The application of EGCG enhanced callus formation by increasing the bone volume and subsequently improved the mechanical properties of the tibial bone, including the maximal load, break load, stiffness, and Young’s modulus. The results of the histology and BMP-2 immunohistochemistry staining showed that EGCG treatment accelerated the bone matrix formation and produced a stronger expression of BMP-2. Taken together, this study for the first time demonstrated that local treatment of EGCG can accelerate the fracture healing process at least partly via BMP-2.

Epigallocatechin-3-Gallate (EGCG), an Active Compound of Green Tea Attenuates Acute Lung Injury Regulating Macrophage Polarization and Krüpple-Like-Factor 4 (KLF4) Expression

“…We found enhanced expression of Ang-1 after treatment with EGCG in LPS-induced ALI. Similar to this, other studies showed beneficial effects on the regenerative capacity of different lung cells [ 48 , 49 ]. The effect of EGCG might be mediated through KLF4, which is a well−known regulator of stem cells and has a role in cell proliferation [ 12 , 50 ].…”

Osteoprotective Roles of Green Tea Catechins

“…Lin et al found that percutaneous local injection of EGCG for 2 weeks, 10 µM/L, 40 µL, enhances callus bone volume and increases the tibial mechanical properties. The break load, maximal load, Young’s modulus, and stiffness improved after EGCG treatment with more BMP-2 expression than that found in male rats without EGCG treatment in a tibia fracture model [ 95 ]. Lin et al also demonstrated that local EGCG (10 µM/L, 40 µL) improves femoral defect healing with de novo bone formation by enhancing the bone volume and improving the mechanical properties similar to the above study.…”

Intra-Articular Injection of (-)-Epigallocatechin 3-Gallate to Attenuate Articular Cartilage Degeneration by Enhancing Autophagy in a Post-Traumatic Osteoarthritis Rat Model

“…EGCG (E4143) was purchased from Sigma-Aldrich (St. Louis, MO, USA) [ 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Purity was 99.6% at room temperature.…”