The saponins have been employed in beverages to give a frothy or foaming effect. The detection of small amounts is very difficult. One method that has been suggested is to test the hemolytic effect of the separated froth.

Many of the saponins are highly poisonous and are therefore known as sapotoxins. The toxic effects appear to be due to their affinity for cholesterin and perhaps also lecithin. By virtue of this combination with these important lipoid bodies they are irritant to mucous membranes and when introduced into the circulation destroy the red blood cells and exercise potent effects upon the central nervous system. The variability in their toxic powers may be gauged by the fact that diocin, when mixed with blood, in as dilute solution as 1 in 400,000, will cause hemolysis while chamaelirin (from Helonias) requires a concentration of 1 in 700. Most of the toxic saponins are unable to pass through the intestinal mucous membranes and when taken by the mouth cause only local irritation of the alimentary canal; agro stemma is a noteworthy exception to this rule. When introduced into the circulation in moderately toxic doses the most obvious symptoms produced by the sapotoxins, are usually on behalf of the nervous system; convulsions followed by motor weakness, and even complete paralysis. Accompanying these nervous symptoms there is often weakness of the heart and evidence of irritation of the serous membranes and eliminating organs. After larger quantities, there is, besides the nervous manifestations, marked failure of the circulation, and vomiting and purging�the ejecta often being bloody. Death is usually due to respiratory failure, but may occur after some days of general exhaustion. When locally applied sapotoxins destroy the contractility of the muscles and the conductivity of the nerves. For studies of the physiological effects of saponins see Ransom (D. M. W., 1901, xxvii, p. 194), Brandl (A. E. P. P., 1905, liv, p. 245 and 1908, lix, p. 299), Yagi (A. B. P. P., 1911, lxiv, p. 141) and Kobert (Biochem. Handlex, 1914, vol. vii).

YUCCA FILAMENTOSA. (Bear-grass)
So-called bilious symptoms, with headache. Despondent and irritable.
Head. � Aches as if top of head would fly off. Arteries of forehead throb. Nose red.
Face. � Yellow; tongue yellow, coated, taking imprint of teeth. [Merc.; Pod.; Rhus.]
Mouth. � Taste as of rotten eggs. [Arnica,.]
Throat. � Sensation as if something hung down from posterior nares; cannot get it up or down.
Abdomen. � Deep pain in right side over liver, going through back. Stool yellowish brown, with bile.
Male � Burning and swelling of the prepuce, with redness at meatus. Gonorrhea. [Cann.; Tussil.]
Skin. � Erythematous redness.
Dose. � Tincture, to third potency.

Yucca Filamentosa, Linn (Bear Grass)
Nat. Ord. Melanthaceae (Liliaceae).
Part used ; Tincture of root and leaves when not in flower. Tincture of flowers.
Clinical Indications. Biliousness. Coryza. Diarrhoea, Flatulence, odourless. Headache; temporal. Post-nasal catarrh. Throat, granular.
Characteristics. Yucca was proved by Rowell and four others in the 30th. Farrington gives these indications. Biliousness with pain going through upper part of liver to back. Bad taste in mouth. Stools loose and contain an excess of bile. Much flatus passed by rectum. Frontal or temporal headache with frequent flushing of face. Face sallow. Tongue coated yellow and taking imprint of teeth. Dull ache in centre of liver. Abdomen sensitive. Frequent passage of flatus and of watery, yellowish-brown stools. The tongue of Yuc. is usually a bluish white. As with many liver disorders, there is chilliness: cannot bear to be away from the fire. Among the sensations are: As of something hanging down from back of nares. As if cold air blowing on left side of scalp. The symptoms are: <; B noise; motion; pressure. Griping pain is > bending forward.

Abridged and edited from :
A Dictionary of Practical Materia Medica.
By John Henry Clarke, M.D.