2.1. Plant material
The dried roots of P. ginseng and bee pollen were used (Dong- sung Pharmaceuticals, Seoul, Republic of Korea). They were identified by Dr. Sang-Won Lee in National Institute of Hor- ticultural and Herbal Science (NIHHS), and voucher speci- mens (numbers KH13 and H14) were deposited with Department of Medicinal Crop Research Institute, NIHHS, Eumsung. We selected P. ginseng for this research. P. ginseng is sensitive to high heat. As P. ginseng grows the precious plants are taken great care daily to insure the highest quality. The P. ginseng garden is covered with straw to control weeds and protect the sensitive young plants from the long cold winter.