"Ginseng (Panax ginseng C.A. Meyer) has been a popular herbal remedy used in eastern Asian cultures for thousands of years, and a number of health claims are made for it. Modern therapeutic claims for ginseng refer to vitality, immune function, cancer, cardiovascular diseases, diabetes and sexual function. These claims are mostly based on uncontrolled or non-randomized studies. Among modern therapeutic claims, however, therapeutic effects for diabetes can reasonably be accepted. Following experiment was done recently in our lab: this study was designed to compare the antidiabetic activities between Ginseng Radix Alba (GRA), Ginseng Radix Rubra (GRR) and Panax Quinquefoli Radix (PQR) in multiple low dose (MLD) streptozotocin (STZ) (20mg/kg i.p injection for 5 days) induced diabetic rats. In the glucose tolerance test, 500mg/kg of each ginseng ethanol extract was admoinistered intraperitoneally 30min before glucose challenge. While GRA failed to lower blood glucose level, GRR and PQR both significantly prevented the hyperglycemia when compared with the control group. In the MLD STZ-induced diabetic rats, 300 mg/kg of each ginseng ethanol extract was administered intraperitoneally for 2 weeks. Plasma glucose and insulin levels were markedly improved in all treatment groups. While GRR showed the highest antidiabetic activity, and GRA and PQR revealed somewhat equipotent antidiabetic activities, but less than that in GRR-treated group as for as blood parameters and diabetic symptoms such as polydipsia are concerned. Blood glucose levels were closely associated with plasma insulin levels, and this result may suggest that ginseng ethanol extracts showed the activity to enhance insulin secretion as well as preventing destruction of pancreatic islet cells. To elucidate the relationship between antidiabetic activity and ginsenoside profiles, seven major ginsenoside were quantified by HPLC. We figured out the fact that protopanaxatriol (PPT) : proptopanaxadiol (PPD) ratio might play an important role in its hypoglycemia effects."