About Adonis vernalis L.
Adonis vernalis L., commonly called pheasant's eye, spring pheasant's eye, yellow pheasant's eye, and false hellebore, is a perennial flowering plant in the buttercup family Ranunculaceae. It grows in dry meadows and steppes across Eurasia, and more specifically can be found in open forests, forest clearings, dry meadows, and mesic steppe, mostly on calcareous soil. Isolated populations occur from Spain in western Europe through Central Europe (with well-documented examples in Valais, Switzerland), across southern Europe, reaching southern Sweden in the north and Abruzzo in the south. Its primary distribution range covers the Pannonian Basin and the West Siberian Plain. Unlike most other European Adonis species, A. vernalis produces flowers in springtime, from around April to May, when the plant's above-ground organs also develop. Flowers can reach up to 80 mm (3.1 in) in diameter, and have up to 20 bright yellow petals. The plant is poisonous, and contains cardiostimulant compounds including adonidin and aconitic acid. Infusions of this plant are an ingredient in the medicinal preparation Bekhterev's mixture. A. vernalis is frequently grown as an ornamental plant. Because Adonis species including A. vernalis have cardiac-enhancing effects, the plant has a long history of use in European and Chinese folk medicine to treat various health conditions. It was used in the Soviet Union to treat edema (swelling), as an alternative cardiac agent. In 1879, Russian physician N. O. Buhnow first introduced alcoholic extracts of the plant into medical use as a cardiac stimulant. In 1898, Vladimir Bekhterev proposed a mixture of this plant extract with sodium bromide or codeine to treat heart diseases, panic disorder, dystonia, and mild forms of epilepsy. In Siberia, aqueous infusions made from the aerial parts of the plant have been traditionally used against edema (including cardiac edema), multiple other heart-related issues, kidney diseases, and malaria. The biological activity of this extract is measured as 50–66 frog units (the amount of liquid substance that causes cardiac arrest in a frog) and 6.3–8.0 cat units (the amount of liquid substance that causes cardiac arrest in a cat), and sufficiently large doses are toxic. A. vernalis contains cardiac glycosides that improve cardiac efficiency by increasing cardiac output and reducing heart rate. These glycosides also produce a sedative effect, and are often prescribed for patients with irregular or increased heart rate. Homeopathic physicians use tinctures of A. vernalis to treat patients with congestive cardiac failure, and the plant's action is very similar to digitalis, another heart muscle stimulating drug. Studies on isolated heart preparations have found aqueous extracts of A. vernalis have cardiac stimulant effects, and also show that production of excessive high potassium concentrations protects against heart failure. The plant also contains flavones that have multiple pharmacological activities, including antioxidant, antimicrobial, anti-inflammatory, neuroprotective, cardioprotective, and anti-allergic properties.
