Pueraria montana var. root extract inhibits photoaging on skin through Nrf2 pathway.

var. is a bioactive substance, in possession of a variety of beneficial health effects, which has long been extensively used as a traditional medication for the treatment of fever, acute dysentery, diabetes, and cardiovascular diseases in North-East Asian countries. The purpose of this study was to evaluate the cytoprotective activity of var. lobata ethanol extract (PLE) for ultraviolet B (UVB) induced oxidative stress in human dermal fibroblasts (HDF). It was hypothesized that PLE treatment (25-100 μg/mL) would reduce intracellular reactive oxygen species (ROS) levels as well as increase collagen production in UVB-irradiated HDF. The results confirmed this theory, with collagen production increasing in the PLE treatment group in a dose-dependent manner. In addition, regulators of cellular ROS accumulation, including HO-1 and NOQ-1, were activated by Nrf2, which was mediated by PLE. Hence, intracellular levels of ROS were also reduced in the PLE treatment group in a dose-dependent manner. In conclusion, PLE increases collagen production and maintains hyaluronic acid (HA) levels in human dermal fibroblasts exposed to UVB-irradiation, thereby inhibiting photoaging.