Scrophulariaceae / Gesneriaceae
Sheng Di huang, gān dì huáng
Raw - Antipyretic, Astringent, Cardio tonic, Demulcent, Diuretic, Hepoprotective, Homeostatic, Hypoglycaemic, Hypotensive, Kidney tonic. Anti- inflammatory , anti fungal Cooked - Homeostatic, Nourishes Yin, Tonic to the Blood
A number of chemical constituents including iridoids, phenethyl alcohol, glycosides, cyclopentanoid monoterpenes, and norcarotenoids. Also β-sitosterol, mannitol, a small amount of stigmasterol and campesterol, iridoid, amino acids, rehmannin, catalpol, dihydrocatalpol, acetyl catalpol, danmelittoside, melittoside, geniposide, ajugoside, daucosterol, 1-Ethyl-β-D-galactoside, rehmannioside A, B, C, D. Organic acids include benzoic acid, caprylic acid, 3-Methoxy-4-hydroxybenzoic acid, cinnamic acid, oleic acid, linoleic acid, palmitic acid, stearic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, tetradecanoic acid, pentadecanoic acid, heptadecanoic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid, behenic acid, etc. Saccharides include stachyose, glucose, sucrose, fructose, raffinose, mannotriose, verbascose, galactose, and vitamin A substances. In addition, fresh rehmannia contains 20 kinds of amino acids, among which arginine has the highest content; dried rehmannia contains 15 kinds of amino acids, among which alanine has the highest level. it also contains iron, zinc, manganese, chromium, and another 20 kinds of trace elements.
This herb can be used both raw and cooked (steamed) The Raw root is used to Lower high blood pressure and regulate blood sugar, it also protects the liver and tonifies the kidneys. It helps soothe inflamed internal tissue, lower fevers and heat in the body. Rehmannia aids in stopping glycogen exhaustion in patients suffering from hypoglycemia. The astringent compounds in rehmannia are effective in stopping bleeding from ulcers as well as in lessening the irritation and swelling in the digestive tract. Other compounds present in rehmannia act to lower the vulnerability of capillary tubes and also assist in protecting the adrenal glands. It also tones the blood and helps with the deficiencies in blood.
Notes: Care should be used when taking Rehmannia with any other medication to control diabetes or cardiac disease. It should be used with caution in the cases of diarrhoea due to spleen deficiency, reduced appetite caused by stomach deficiency, and excessive phlegm in chest. For those taking blood pressure and heart medications such as beta-blockers, clonidine, hydralazine, the herb should only be used under the guidance of a physician.