Saponins from the roots of Platycodon grandiflorum suppress ultraviolet A-induced matrix metalloproteinase-1 expression via MAPKs and NF-κB/AP-1-dependent signaling in HaCaT cells

► The protective effects of CKS against UVA damage and its molecular mechanism were investigated. ► CKS increased the cell viability and inhibited ROS production and MMP-1 expression. ► CKS suppressed UVA-induced expression of inflammatory cytokines and collagen degradation. ► CKS suppressed UVA-induced activation of NF-κB or AP-1, and the phosphorylation of MAPKs. ► CKS exerts potent anti-photoaging activity by inhibition of MMP-1 expression and MAPKs activity.