Antipruritic Effects of Puerariae Radix on 5-HT or AEW-Induced Itch Behavior in Mice

5-HT 및 AEW로 소양증(搔痒症)을 유발한 흰쥐에 대한 갈근(葛根)의 진양(鎭痒)효과

Objectives : To find antipruritic herbal medicines, we screened the water extracts of four herbal medicines which have been frequently prescribed to treat dermatologic diseases in oriental medicine. Methods : Water extracts of Bupleuri Radix, Scutellariae Radix, Cimicifugae Rhizoma and Puerariae Radix were administered at a dose of 300 mg/kg to male ICR mice. 1 hour later, serotonin hydrochloride dissolved in physiologic saline at a concentration of 100 nmol / 50${\mu}{\ell}$ was administered intradermally to the nape of the neck at a dose of 50${\mu}{\ell}$. Then the scratching behavior was observed. Dry skin pruritus was induced with cutaneous application of acetone / ether (1:1) mixture and water (AEW) to the rostral back of male ICR mice, twice a day for 5 days. 14 hours after the last application, the most effective material in the first experiment was administered perorally at doses of 75, 150, 300, 600 and 1200 mg/kg. 1 hour later, the scratching behavior was observed. Results : Water extracts of Puerariae Radix significantly inhibited the serotonin-induced scratching behavior and the mean of scratching bouts was reduced by half compared with the control group. Bupleuri Radix group also showed a 29% decrease in the mean of scratching bouts, but there was no statistical significance. Water extracts of Puerariae Radix also inhibited the AEW-induced scratching behavior, in a dose-dependent manner. The dose of 150 mg/kg showed the highest and statistically significant antipruritic effect. Conclusions : These results suggest that Puerariae Radix and its constituents have antipruritic effect, and are new candidates as antipruritic agents.