MMP-1 suppressing activity of high-molecular weight fraction isolated from the roots of Cynanchum wilfordii Hemsley

Cynanchum wilfordii Hemsley is a traditional herbal medicine that has been widely used in Asia. In the present study, we investigated the MMP-1 suppressing activity of a high-molecular weight fraction isolated from the roots of C. wilfordii Hemsley (HMF). In human skin tissue, UVB irradiation significantly increased matrix metalloproteinase-1 (MMP-1) expression, while HMF suppressed this effect. The inhibitory effect of HMF was confirmed in both primary human dermal fibroblasts (HDFs) and a human keratinocyte (HaCaT) model. An investigation of the underlying mechanisms responsible revealed that MKK4-JNK, MEK-ERK, and MKK3/6-p38 phosphorylation was downregulated by HMF treatment. HMF also induced a 30–40% increase in DPPH radical scavenging activity and recovered expression levels of the antioxidant enzyme superoxide dismutase. Taken together, these findings suggest that HMF elicits MMP-1 suppressing activity via inhibition of the signaling that drives UVB-induced oxidative stress in human skin.