Rehmannia(Rehmannia Glutinosa) is the name that unites the genus of six flowering species in the Lamiales order, although the plant doesn’t belong to any of the families due to particular molecular structure. Although, some classifications attribute it to the Scrophulariaceae family. This perennial herb is native to the East – Korea, China, and Japan. Its origin defined its place in the Oriental herbal medicine where it is one of the 50 basic herbs used in blends and individually. The plant is known as dìhuáng (earth yellow) in Chinese medicine. Rehmannia is recognized by the bell-shaped flowers of yellowish or reddish-violet color and leaves growing close to the ground. The plant usually grows up to 15-30 cm. In the USA it is cultivated for ornamental uses, while in the Eastern herbal medicine it is used as a herbal remedy.
Rehmannia grows best in the temperate regions and favors medium sun and sandy, loamy, well-drained soils, especially in the first years of growth. Matured, it can be rather drought and frost tolerant plant, surviving up to -25°C (provided the flowers are dry so they do not rot). The flowering period is April through June, whereas the seeds appear in March and ripen till July.
Root of the plant is the major source of beneficial compounds in the rehmannia. It is used fresh, dried or processed into herbal preparations. Leaves serve as a topical application for skin conditions, such as psoriasis or eczema. Other than for decorative purposes, the use of the rehmannia flowers is not known.
As a rule, rehmannia root is sold in capsules, tablets, dried extracts, and powder. Rehmannia is a compound of a variety of herbal blends and formulas, such as those for female health enhancement, in particular.
Rich in amino acids,Vitamins (A, B, C), cerebroside, melittoside, dammelittoside, and rehmaglitin, rehmannia is known as anti-inflammatory and anti-fungal herb. It is also known as a blood tonic and purifier – thanks to its astringent properties provided by the chemical content. The rich sweet starchy content of the rhizome has been used in Chinese herbal medicine as a cloying agent – improving the function of the liver and digestion (by stimulating bloating and gas). Other benefits associated with rehmannia include anti-hepatotoxic, anti-rheumatic, anti-eczema, diuretic, hypoglycemic, laxative and cardiotonic actions.
Iridoid glycosides are the major constituents in the root. They stimulate the production of anti-inflammatory hormones and work well in treating conditions associated with hormone deficiencies.
Rehmannia is majorly associated with adrenal gland and kidney conditions. It decreases adrenal suppression of steroid hormones and works well against autoimmune disorders (fibromyalgia, rheumatoid arthritis, and multiple sclerosis).
Restorative properties of rehmannia have been known for centuries in Chinese herbal medicine. Today, it is commonly used in the patients with broken bones – for repairing damaged center, broken bones, and enhancing the regeneration of muscles and tissues.
The vitamin content make rehmania an effective remedy for fever and colds, inflammation and dizziness.
Women with severe PMS and menstrual disorder symptoms will find rehmannia helpful for the major troubles of the condition. Its action stimulates hormonal balance, reduces bleeding, relieves anemia, headaches, and regulates menstrual cycle.
Astringent properties of Rehmannia make it useful in treating external and internal bleeding – it stops blood in ulcers, wounds, nasal and vaginal bleeding. Moreover, the herb will purify the blood and reduce the pressure in it.
Chinese herbalist use rehmannia as multi-purpose tonic. Its action improves kidney function, urinary tract health (especially in men), cardiovascular system and cholesterol levels, blood circulation, digestion, deafness, vertigo and sexual health. Tonic properties make rehmannia an anti-aging herb. The animal study was based on controlling life extending effects of the herb and used old rats. Those that were associated with rehmannia usage showed an increased stamina and moved more on the running-wheel as compared to those that did not consume the herb.
When applied to skin, rehmannia treats eczema, psoriasis, wounds and cuts.
Preagnant or breastfeeding women should not use rehmannia. Some rare side effects include bloating, nausea, and loose bowel movements.