Effects of some kampo medicines on plasma levels of neuropeptide Y under venipuncture stress.

Some traditional Chinese herbal (Kampo) medicines have recently been evaluated for their clinical usefulness in stress and depression. These medicines have modulatory effects on the hypothalamic-pituitary-adrenal axis and sympathetic nervous system (SNS). We examined the effects of Rikkunshi-to, Hange-shashin-to, Hange-koboku-to, and Ninjin-to on plasma levels of neuropeptide Y (NPY), which is the representative neurotransmitter of the SNS, under venipuncture stress. Rikkunshi-to and Hange-shashin-to suppressed increases in plasma NPY-immunoreactive substance levels compared with the response to a placebo. In this study, Rikkunshi-to and Hange-shashin-to altered plasma levels of NPY under venipuncture stress. These effects might be beneficial in stress-related diseases and our results suggest that these medicines have clinical pharmacologic activity.