Effect of Pg-C-EE on moisture retention and collagen synthesis in HaCaT cells. (A) Expression of NMF synthesis–related genes (FLG, TGM-1, and HAS-1, -2, and -3) was measured by RT-PCR in HaCaT cells treated with Pg-C-EE (100 μg/mL, 200 μg/mL, and 400 μg/mL) and retinol (10 μg/mL) for 24 h. (B) mRNA expression of HYAL-1, -2, -3, and 4 was determined by RT-PCR in HaCaT cells after irradiation with UVB (30 mJ/cm2) for 24 h and treatment with Pg-C-EE (100 μg/mL, 200 μg/mL, and 400 μg/mL) and retinol (10 μg/mL). (C) Col1A1 and Col2A1 mRNA expression was analyzed using RT-PCR in HaCaT cells treated with Pg-C-EE (100 μg/mL, 200 μg/mL, and 400 μg/mL) and retinol (10 μg/mL) for 24 h. Col1A1, collagen, type I, alpha 1; Col2A1, collagen, type II, alpha 1; FLG, filaggrin; HAS, hyaluronic acid synthase; HYAL, hyaluronidase; NMF, natural moisturizing factor; Pg-C-EE, Panax ginseng calyx ethanol extract; RT-PCR, reverse transcription polymerase chain reaction; TGM-1, transglutaminase-1; UVB, ultraviolet B.