§ 592. Effects on Man.—Only two fatal cases of poisoning by picrotoxin are on record. In 1829 several men suffered from drinking rum which had been impregnated with Cocculus indicus; one died, the rest recovered. In the second case, a boy, aged 12, swallowed some of a composition which was used for poisoning fish, the active principle of which was Cocculus indicus; in a few minutes the boy experienced a burning taste, he had pains in the gullet and stomach, with frequent vomiting, and diarrhœa. A violent attack of gastro-enteritis supervened, with fever and delirium; he died on the nineteenth day. The post-mortem signs were those usual in peritonitis: the stomach was discoloured, and its coats thinner and softer than was natural; there were also other changes, but it is obvious that, as the death took place so long after the event, any pathological signs found are scarcely a guide for future cases.
§ 593. Physiological Action.—The convulsions are considered to arise from an excitation of the medulla oblongata; the vagus centre is stimulated, and causes spasm of the glottis and slowing of the heart’s action during the attack. Röhrig also saw strong contraction of the uterus produced by picrotoxin. According to the researches of Crichton Browne, chloral hydrate acts in antagonism to picrotoxin, and prevents the convulsions in animals if the dose of picrotoxin is not too large.
§ 594. Separation from Organic Matters.—Picrotoxin is extracted from aqueous acid solutions by either chloroform, amyl alcohol, or ether; the first is the most convenient. Benzene does not extract it, if employed in the same manner. On evaporation of the solvent the crude picrotoxin can be crystallised out of water, and its properties examined.
R. Palm[613] has taken advantage of the fact that picrotoxin forms a stable compound with freshly precipitated lead hydroxide, by applying this property as follows:—the solution supposed to contain picrotoxin is evaporated to dryness, and the extract then taken up in a very little water, acidified and shaken out with ether. The ether is evaporated, the ethereal extract dissolved in a little water, the aqueous solution filtered through animal charcoal, and precipitated by means of lead acetate, avoiding excess. The solution is filtered and shaken with freshly prepared lead hydroxide. The lead hydroxide is dried and tested direct for picrotoxin; if it does contain picrotoxin then on adding to it concentrated H2SO4 a beautiful saffron yellow is produced as bright as if the substance was pure picrotoxin.
[613] J. Pharm., (5), xvii. 19-20.
III.—The Poison of Illicium Religiosum—A Japanese Plant.
§ 595. A new poison belonging to the picrotoxin class has been described by Dr. A. Langaard. In 1880, 5 children in Japan were poisoned by the seeds of the Illicium religiosum; 3 of the children died. Dr. Langaard then made various experiments on animals with an active extract prepared by exhaustion with spirit, and ultimate solution of the extract in water. Eykmann has also imperfectly examined the chemistry of the plant, and has succeeded in isolating a crystalline body which is not a glucoside; it is soluble in hot water, in chloroform, ether, alcohol, and acetic acid, but it is insoluble in petroleum ether; it melts at 175°, and above that temperature gives an oily sublimate. Langaard’s conclusions are that all parts of the plant are poisonous. The poison produces excitation of the central apparatus of the medulla oblongata and clonic convulsions analogous to those produced by picrotoxin, toxiresin, and cicutoxin. Before the occurrence of convulsions, the reflex excitability of frogs is diminished, the respiratory centre is stimulated, hence frequency of the respiration. Small doses cause slowing of the pulse through stimulation of the vagus and of the peripheral terminations of the vagus; in the heart the functional activity is later diminished. Small doses kill by paralysing the respiratory centre, large by heart paralysis. The proper treatment seems to be by chloral hydrate, for when animals are poisoned by small lethal doses it appears to save life, although when the dose is large it has no effect.—Ueber die Giftwirkung von Japanischem Sternanis (Illicium religiosum, Sieb.), Virch. Archiv, Bd. lxxxvi., 1881, S. 222.