This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Hay-fever is a pollen-protein anaphylaxis, the victim having become sensitized to a vegetable protein. This brings up the whole question of protein sensitization; but we will discuss it here only as related to vegetable proteins.
Many people are anaphylactic to certain fruits, as strawberries and apples. Dr. Walter F. Chappell, New York City, read a paper recently before the American Laryngological Association and detailing experiments upon persons anaphylactic to apples, strawberries, and tomatoes, with proper control experiments upon normal individuals. Terrific reaction followed the injection of one minim sub-cutaneously of apple protein extract of a 1:60,000 strength. Strawberry and tomato protein gave milder reactions.
Persons sensitive to fruit proteins develop urticaria, vomiting, and angio-neurotic edema. Fago-pyrism, or buckwheat poisoning, is a form of anaphylactic shock. Hay-fever is marked by asthmatic symptoms somewhat similar to the asthma induced by horse-serum sensitization.
Blackfan (Am. Jour. Dis. Child., June, 1916) advances a theory that there is an etiologic relationship between protein sensitization and eczema, and he finds that a person sensitive to one protein is apt to be sensitive to several. As involves the vegetable proteins, this is certainly true.
Ricin, the tox-albuminoid principle found in castor-oil seeds, is an intensely poisonous phyto-albuminose found in the endosperm and embryo; chemically it is analogous to the bacterial toxins and ferments, but is stable in the alimentary tract. The lethal subcutaneous dose for man is so small it is best expressed in the metric scale as 0.003 gm. Fifteen grains of it is sufficient to kill one and a half million guinea pigs. By injection of infinitesimal doses, antiricin is formed in the body, and immunity is established.
The study of ricin by Ehrlich laid the foundation of serum therapeutics. Antiricin is an antitoxin formed in the blood of a person taking fractional doses of ricin.
Abrin, from Abrus precatorius (see "Jequirity"), and crotin, from Croton tiglium or Croton Oil, a vicious purgative in 1-minim doses, closely resembles ricin. Toxins have also been obtained from poisonous mushrooms. Doubtless animals could be immunized to all of these vegetable proteins (See Pharm. Jour, of Great Britain, Feb. 6, 1915).
It impresses me that the endosperms and embryos, the pollens, and probably other protein-carriers of plant life, may, many of them, carry substances which are highly toxic when subcutaneously injected, and which would develop antitoxins, as antiricin. Of course antiricin is a remedy only to ricin, and otherwise it has no medicinal action, so far as we know. A plant is a toxin, possibly, and may develop an antitoxin but only in the body.
But, as in Dunbar's serum for hay-fever, an amboceptor, not an antitoxin, was the basis of its activity. Any form of foreign protein parenterally introduced gives rise to the formation of antibodies. It is probable the future will develop much as regards the vegetable proteins.
Now as regards hay-fever - pollinosis, if you will - and the use of pollen extracts.
It is quite generally believed that protein cleavage, or the split protein, is responsible for hay-fever anaphylaxis, and Vaughan's theory throws light on the subject. It may be that there is, fundamentally, but one protein poison involved.
Pollantin, Dunbar's Serum, has no pharmacologic action; it contains an amboceptor (possibly some antitoxin) developed in the blood-serum of horses treated with pollen derived from ragweed. One drop is instilled by means of a pipette into the outer angle of each eye and one or two drops into one nostril (the other being kept closed) every morning before rising. Apply four times. It is a good prophylactic and is effective in a certain proportion of developed cases. Pollantin is also supplied in powder; it keeps better than the liquid.
Pollen Extract, or Pollen Vaccine, is a solution of pollen protein. It is prepared from several plants, as timothy pollen extract, ragweed pollen extract, and pollen extract combined. The patient's susceptibility may be tested by rubbing a small quantity of the pollen vaccine into a scratch of the skin; if the patient is sensitive to that particular pollen, an urticarial wheal results. First test out the susceptibility, and wait until the wheal has completely subsided; then use the appropriate vaccine according to the printed directions accompanying the package. The proper doses are given subcutaneously. Pollen vaccine is used both for prophylactic and curative treatment.
The use of a pollen vaccine develops a certain degree of immunity, just as the use of ricin in minute doses develops the antitoxic antiricin; but no protein, vegetable or animal, is of itself an antitoxin. The claim that echinacea or lobelia, q. v., even if injected hypodermatically, has an antitoxic value in disease is preposterous; but it is a theoretical possibility that vegetable proteins, when injected, develop an immunizing body against their own action. If we were to find a vegetable protein that developed a train of pathologic symptoms paralleling those of some clinically defined disease, then it might be theoretically possible, by injecting a dilution of that protein, to establish a degree of immunity to the parallel disease. Nevertheless, this is pure theory. But it might be, for instance, that spasmodic asthma could be influenced by certain pollen proteins.
There are plenty of vegetable proteins upon which to experiment if one cares for such research. The toxic ones - abrin, crotin, and ricin - should be handled infinitely diluted; but there are many of less toxicity.
Globulin may be readily separated from wheat or cotton-seed, amandin from almonds, corylin from hazel-nut, excelsin from Brazil-nut, edestin from hemp-seed, vignin from cow-pea, glycinin from soybean, legumin from the lentil or the vetch, phaseolin from kidney-bean, conglutin from blue lupine seed, and hordein from barley. (See Osborne on "The Vegetable Proteins," Longmans, Green & Co., London.)
The medicinal use of buckeye, horse-chestnut, anacardium, worm-seed, buckwheat, castor-bean, ignatia bean, jatropha (purging nut), butternut, peach seed, lobelia seed, nutmeg, Calabar bean, acorn kernels, cevadilla seed, kola nut, Kombe-seed, jambol-seed, tonka-bean, and host of other seeds and nuts, may, in some instances, be partly due to the activity of plant proteins, at least so far as hypodermic use is involved. But it will require a vast deal of laboratory research to bring to light anything of clinical significance. Meanwhile let us not assert that anything is a "vegetable antitoxin." But it may readily be that certain of the plant proteids may be of value in the production of some degree of immunity.