Platycodon grandiflorum-derived saponin attenuates the eccentric exercise-induced muscle damage

Platycodon grandiflorum contains triterpenoid saponins, such as platycodin D and platyconic acid A, and acts as a multifold nutritious compound. Our previous research demonstrated that Platycodon grandiflorum-derived saponin (PS) improves high-fat diet-induced non-alcoholic steatohepatitis and inhibits osteoclast differentiation. The pivotal effects of PS on inflammatory mechanism were suppressed NF-κB and matrix metalloproteinase (MMPs). However, the effects of PS on skeletal muscle damage remain unknown. Therefore, we investigated whether PS protects against eccentric exercise-induced muscle damage. A significant reduction in eccentric exercise-induced muscle damage area and muscle damage related to the level of NF-κB p65 by PS was associated with the downregulation of ERK/p38/SMAD signaling. Eccentric exercise caused muscle damage by increasing the serum lactate dehydrogenase (LDH), creatinine kinase (CK) and C-related protein level. The serum LDH, CK and C-related protein level was significantly lower in the PS supplementation group compared with the control group. Moreover, PS was inhibited MMP-1, MMP-2 and MMP-9. PS protects against eccentric exercise-induced muscle damage. Together, these results provide a novel perspective on the biological function of PS against muscle damage.