Dioscorea nipponica extracts enhance recovery from skeletal muscle atrophy by suppressing NF-κB expression

Saponin derived from natural extracts can alleviate muscle atrophy. Dioscorea nipponica Makino (DNM) is commonly used in herbal medicine and contains various steroidal saponins, although its efficacy and mechanisms of action for treating muscle atrophy remain unknown. Here, differentiated myoblast cells treated with DNM showed increased MyoD and MyoG expression and effectively promoted muscle formation. DNM effectively inhibited muscle atrophy induced by tumor necrosis factor alpha (TNF alpha) monotherapy, and combination treatment with protodioscin and protogracillin (among the tested DNM constituents) showed a synergistic effect on differentiated myoblast cells. DNM and this combination repressed TNF alpha-induced increased MuRF1 and Atrogin1/MAFbx expression by inhibiting nuclear factor-kappa B (NF-kappa B) expression. DNM also effectively promoted the recovery of muscle formation in injured mice. Therefore, DNM and its multi-constituents can potentially be used as therapeutic agents for muscle-related diseases and represent prospective food supplements.