Recently, several growth factors related to the hair growth cycle have been reported [9—14]. In this experiment, we used semi-quantitative RT-PCR analysis to search for growth factors that were affected by the A. radix extract. We measured the expression
levels of IGF-1, KGF, HGF, VEGF (stimulating effect on hair growth), and TGF-b1 (inhibitory effect on hair growth). There were no significant changes in the growth factor expression of HaCaT cells (Fig. 5A). However, when the DP cells were treated
with the A. radix extract at dosages of 0.000001% and 0.00001%, the level of VEGF mRNA expression increased significantly at the indicated time-points.
(Fig. 5B). To further verify the induction of VEGF mRNA alternative spliced form, we performed realtime PCR analysis. A. radix extract (0.00001%) increased the VEGF 121 and VEGF 165 mRNA level by 129% and 126%, respectively, 24 h after treatment, as compared to control group (Fig. 5C).