biological assay of rhubarb

The present study was undertaken to standardize the assay method for the cathartic effect of rhubarb in mice. Examinations were made on the effect of administration time, age, sex, and body weight of mice, light, other drugs, fatigue and fasting of mice, temperature, and humidity. The ED50 value of rhubarb was affected by administration time. Three-week-old mice were less sensitive than 4- to 7-week-old mice. In a group of the same age, mice of heavy body weight were more sensitive than light ones. The ED50 values were also affected by lighting and simultaneous administration of some other drugs. Other factors were found to be insignificant.