50 albino mice divided equally in two groups were tested with oral administration of the crude extract of Plumbago zeylanica and the fresh latex of Calotropis gigantea. The local effect of these crude drugs showed thinning of the stomach wall and that of the small intestine. Histopathological studies show congestion of blood vessels in heart, lung, kidney and liver. Haemorrhages were seen in the cardiac muscle and pulmonary tissue. The mode of action of these toxins is discussed and further histochemical and biochemical investigations are in progress.