Fig. 1

SG-callus extract and its major component, shikimic acid, induce stemness in human fibroblast and expression of pluripotent stem cell markers. a Bright-field images of HDF after treatment with SG callus extract (500 μg/ml) for 7 days. Scale bar = 500 μm. b RNA expression of OCT4, NANOG, and Sox2 were analyzed by qRT-PCR. It was normalized to 18s RNA (N = 3 in each group, **p < 0.01). c HPLC chromatogram of the SG-callus extract detected at the UV wavelength of 230 nm. The peak (RT = 4.248 min) is assigned to the shikimic acid. The peak (RT = 18.666 min) is assigned to the caffeic acid. The peak (RT = 21.672 min) is assigned to the trans-ferulic acid. d A colony formation assay was performed on naive HDF and HDF treated with SG-callus extract or shikimic acid, caffeic acid, and trans-ferulic acid at 10 days after treatment. Scale bar = 500 μm. Representative pictures are shown. e Relative stained colonies are quantified (N = 3 in each group, *p < 0.05, ***p < 0.001 compared with the control)