The Biological Assay of Vegetable Purgatives

Abstract

Summary A method for the biological assay of vegetable purgatives based on the number of wet fæces produced by groups of mice after dosing is described. The relation of the number of wet fæces per kg. of mouse to the logarithm of the dose was found to be linear. 40 mice divided equally into 4 groups were used in each assay.*** 2 groups received the standard preparation and the other 2 groups received the test preparation. The standard deviation of a single determination based on 9 such assays was estimated to be 15ṁ7 per cent. The limits of error (P = 0ṁ99) for a single assay are 100±40ṁ5 per cent. A special cage has been designed for this assay, and it has been found advantageous to incorporate a definite proportion of water in the diet, during test. The method described is not only convenient in use but also gives a comparatively high degree of accuracy. The method has been successfully applied to senna leaf, senna fruit and extracts and commercial preparations made from these drugs, pure glycosides (sennosides A and B), and pure anthracene compounds (aloe-emodin and aloe-emodin anthranol).