Abstract
Gintonin is a newly discovered component of ginseng and acts as a ligand for G protein-coupled lysophosphatidic acid (LPA) receptors. It is currently unclear whether gintonin has skin-related effects. Here, we examined the effects of a gintonin-enriched fraction (GEF) on [Ca2+]i transient induction in human dermal fibroblasts (HDFs). We found that GEF treatment transiently induced [Ca2+]i in a dose-dependent manner. GEF also increased cell viability and proliferation, which could be blocked by Ki16425, an LPA1/3 receptor antagonist, or 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl ester) (BAPTA-AM), a calcium chelator. We further found that GEF stimulated hyaluronic acid (HA) release from HDFs in a dose- and time-dependent manner, which could be attenuated by Ki16425, U73122, a phospholipase C inhibitor, 2-Aminoethoxydiphenyl borate (2-APB), an IP3 receptor antagonist, and BAPTA-AM. Moreover, we found that GEF increased HA synthase 1 (HAS1) expression in a time-dependent manner. We also found that GEF stimulates collagen release and the expression of collagen 1, 3, and 7 synthases in a time-dependent manner. GEF-mediated collagen synthesis could be blocked by Ki16425, U73122, 2-APB, and BAPTA-AM. GEF treatment also increased the mRNA levels of LPA1-6 receptor subtypes at 8 h and increased the protein levels of LPA1-6 receptor subtypes at 8 h. Overall, these results indicate that the GEF-mediated transient induction of [Ca2+]i is coupled to HA and collagen release from HDFs via LPA receptor regulations. We can, thus, conclude that GEF might exert a beneficial effect on human skin physiology via LPA receptors.