Keishibukuryogan, a Traditional Japanese Medicine, Inhibits Platelet Aggregation in Guinea Pig Whole Blood

Effects of keishibukuryogan (KBG) on platelet aggregation were investigated. To ensure the specificity of KBG, tokishakuyakusan (TSS) and kamisyoyosan (KSS), which are known to have platelet aggregation-inhibiting effects, and rikkunshito (RKT) and shakuyakukanzoto (SKT), which are considered to be devoid of such effects, were used for comparison. The platelet aggregation of each test drug was measured by the screen filtration pressure method using whole blood of guinea pigs and expressed as a collagen-induced pressure rate (%) or a collagen concentration required for 50% increase in the pressure rate (PATI value). KBG suppressed the collagen-induced whole blood pressure rate increase and increased the PATI value, like TSS and KSS. Neither RKT nor SKT showed these effects. The Moutan cortex and Cinnamomi cortex, the constituent crude drugs of KBG, showed KBG-like pressure rate suppression and PATI-increasing effects. Furthermore, paeonol, a representative component of Moutan cortex, and aspirin which is known to have platelet aggregation-inhibiting activity (COX-1 inhibitor) also showed similar effects. These results suggest that the platelet aggregation-inhibiting activity of the constituent crude drugs Moutan cortex and Cinnamomi cortex is involved in the improving effects of KBG on impaired microcirculation and that paeonol plays a role in these effects

Antiallodynic Effect of Herbal Medicine Yokukansan on Peripheral Neuropathy in Rats with Chronic Constriction Injury

Yokukansan, one of the traditional Japanese herbal medicines, ameliorated neuropathic pain symptoms in patients. In this study, we investigated the effects of yokukansan on neuropathic pain in chronic constriction injury (CCI) model. Oral administration of yokukansan significantly inhibited mechanical and cold allodynia in the von Frey hair or acetone test, respectively. In comparison, amitriptyline, a tricyclic antidepressant, demonstrated moderate, but not significant, antiallodynic effects in the mechanical and cold tests. Yokukansan significantly inhibited the cerebrospinal fluid dialysate level of glutamate that had increased by the stimulation of brush or acetone. Glutamate transporter inhibitors, DL-threo-beta-hydroxy aspartate and dihydrokainate, decreased the yokukansan-induced antiallodynic actions in CCI rats. Our results suggest that yokukansan was confirmed to have antiallodynic effects in CCI rats, which are related to a blockade of glutamatergic neurotransmission via activation of glutamate transporters in the spinal cord