Mechanisms of green tea-induced attenuation of osteoporosis and skeletal muscle atrophy: current status and future study recommendations for clinical application

Epigallocatechin gallate (EGCG), have been reported to attenuate skeletal muscle atrophy and osteoporosis. This review first examines the relationship between the beneficial effects of EGCG and its ability to enhance stem cell function by improving cellular antioxidant capacity. It subsequently identifies key areas warranting further investigation to support the clinical application of EGCG. Stem cell function is essential for the maintenance of muscle and bone mass; however, it declines with aging, largely due to the excessive accumulation of reactive oxygen species and dysregulation of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), processes that ultimately contribute to skeletal muscle atrophy and osteoporosis. Current evidence indicates that EGCG-mediated amelioration of these conditions is associated with increased stem cell function via increasing mitochondrial function, autophagy, antioxidant gene induction, and YAP/TAZ activation, all of which are mutually interconnected and ultimately improve cellular antioxidant capacity. Although clinical studies remain limited, available data suggest that green tea consumption, particularly when combined with exercise, may be a promising strategy for attenuating skeletal muscle atrophy and osteoporosis in humans. Furthermore, the mechanisms proposed in preclinical studies may underlie the effects of EGCG or green tea in humans, although validation in rigorously designed clinical studies is necessary.