Fig. 1. Screened herbal extracts increased lipid synthesis via the adiponectin signaling pathway in keratinocytes. (A~C) Lipid quantification (cholesterol, fatty acids, ceramides, sphingosine, and sphingosine-1-phosphate) was performed by high-performance liquid chromatography in HEKs after 24 hours of treatment with adiponectin (10 µg/ml) or herbal extracts (10 ppm). (D~E) Quantitative real-time PCR of major lipid synthesis enzymes and their regulatory factors in adiponectin or herbal extract treated HEKs. (F) PCR results of the expression of epidermal differentiation markers (filaggrin, involucrin, and loricrin). Values are presented as mean±standard deviation (^*p<0.05, ^**p<0.01, ^***p<0.001 versus control; ^†p<0.05 vs. adiponectin). HEK: human epidermal keratinocyte, NS: non-hydroxy sphingosine, NP: non-hydroxy phytosphingosine, AS: alpha-hydroxy sphingosine, SIRT: sirtuin, SREBP: sterol regulatory element-binding protein.