[Pharmacological effects of Gosha-jinki-gan-ryo extract: effects on experimental diabetes]

Pharmacological effects of Gosha-jinki-gan-ryo extract (KJE) on experimental diabetes induced by cyproheptadine (CPH), aldose reductase activity, and experimental peripheral neuropathy were studied. The effects of KJE were compared with those of Hachimi-jio-gan-ryo extract (HJE). KJE at 417 mg/kg/day (5 times the daily dose in humans) and HJE at 367 mg/kg/day (5 times the daily dose in humans) significantly inhibited the decrease in glucose tolerance by CPH. KJE and HJE inhibited aldose reductase activity, when DL-glyceraldehyde was used as substrate, with IC50 values of 2.68 x 10(-5) g/ml and 4.45 x 10(-5) g/ml, respectively and when D-glucose was used as substrate, with IC50 values of 1.04 x 10(-4) g/ml and 1.55 x 10(-4) g/ml, respectively. KJE at 209 mg/kg/day (2.5 times the daily dose in humans) and HJE at 367 mg/kg/day significantly reduced peripheral neuropathy induced by crushing the sciatic nerve in rats. The potency of these effects of KJE was stronger than that of HJE, when a comparison was made on the basis of the daily dose.