Hellebore

HELLEBORE, Helleborus, a perennial herbaceous plant of the buttercup family (Ranunculaceae) with a well-developed rhizome; it grows in southern and western Europe. Species of Hellebore—H. viridis L., H. niger L., and H. foetidus L.—contain the glycosides helleborein and helleborin in their rhizomes and leaves. Helleborein is an almost colorless or pale yellow powder, odorless, with a sweetish taste and a weakly acidic reaction, with a composition that has not yet been fully established: C₂₆H₄₁O₁₅ (Husemann and Marmé) or C₃₇H₅₆O₁₈ (Thaeter); it is easily soluble in water. It is highly toxic, irritates mucous membranes, and causes sneezing, diarrhea, increased urination, slowing of the heartbeat, arrhythmia, and cardiac arrest in systole; it causes slowing and difficulty in breathing and, finally, respiratory arrest after the cessation of the heartbeat; it also causes convulsions and paralysis of the nervous system. Helleborein is classified among the group of cardiac poisons of the digitalis type. Helleborin is a shiny white, odorless, neutrally reacting crystalline powder with the composition C₃₆H₄₂O₆; it is insoluble in water, slightly soluble in ether, and easily soluble in alcohol and chloroform; it is highly toxic: it causes depression of the central nervous system, which is followed by paralysis. Both glycosides are not used in therapy. In the past, preparations from the rhizome were sometimes used (powder at 0.03–0.3 per dose, alcoholic tincture, and decoction of 0.2–2.0 per 100.0 at 10–20 drops per dose) as stimulants for heart activity, laxatives, and to induce menstruation, but now the use of these preparations has been abandoned due to the toxicity of hellebore.