Choto-san prevents occurrence of stroke and prolongs life span in stroke-prone spontaneously hypertensive rats.

The effects of long-term oral administration of choto-san (diao-teng-san in Chinese) extract on the occurrence of stroke and life span were investigated in stroke-prone spontaneously hypertensive rats (SHR-SPs). Twenty-four rats were ramdomized into three groups. From 8 weeks of age, 0.1% and 0.3% choto-san groups were given water containing 0.1% (150 mg/kg/day) and 0.3% (450 mg/kg/day) choto-san extract, respectively. A control group was given only water. The mean survival times of the control group, 0.1% and 0.3% choto-san groups were 122.1, 159.8 and 176.8 days, respectively. The percent survivals of both the 0.1% and 0.3% choto-san groups were significantly enhanced compared to the control (Kaplan-Meier analysis followed by log-rank test; 0.1% choto-san: p < 0.05; 0.3% choto-san: p < 0.05). Furthermore, the cumulative percent occurrence of neurological and behavioral signs accompying stroke in the 0.3% choto-san group was significantly inhibited compared to the control (p < 0.05). These results suggested that choto-san prevents the occurrence of stroke and prolongs the life span of SHR-SPs.