What Herb am I? - Amy Watson, MA, VetMB, MRCVS, CCRT, CVA
This herb is a sticky root that belongs to the family Scrophulariaceae. It has a large purplish flower. It grows in well draining ground alongside roadsides in the woods, mouth slopers and trail sides at sea level and a little high. It is native to East Asia, Northern China and Korea. Hummingbirds are attracted to it. There are three types used as a herb in TCVM, a fresh root version which is bitter, sweet and cold, a dried unprocessed root which is mostly used to clear heat in the blood and a dried processed root (steamed in water or liquor) which is the strongest tonifier of the three types and is also sweet but slightly warming. This last type is the herb we are looking at in this ‘guess the herb.
The herb contains various active compounds including Catalpol, glutinoside, Rehmnannans, Stachyose, vimtains A, B, C and D and Zinc. It also contains the sugars D-mannitol, sucrose, galactose, fructose and glucose. Catalpol makes up 1-2% of the dried root type we are looking at, and is involved in the production of sex hormones and stimulates the production of adrenal cortical hormones. There is also some research suggesting that catalpol may prevent cell death caused by neurodegenerative disorders.
The herb enters the Liver and Kidney meridians and, according to some sources, the Heart. It is sweet and slightly warming. It Tonifies Blood and augments the Marrow, Nourishes Yin, relieves Wasting and Thirsting Disorder (Xiao Ke), and Tonifies the Essence. It is an antitussive and arrests wheezing. Western uses include use as an analgesic, a tonic, an anti-inflammatory, an antihypertensive. It has also been shown to facilitate the treatment of anaemia by stimulating stem cell lines in the bone marrow to produce and release red bloods cells. It is often used in renal disease and has been shown to reduce serum creatinine, urinary protein excretion and glomerulosclerosis. Small doses constrict blood vessels and large doses cause vasodilation. It possesses the characteristics of a diuretic. It can also decrease blood sugar.
Care must be given to using this herb in patients with Spleen of Stomach Deficiency and if there is Blood Stagnation (unless used alongside Blood moving herbs) because of its stagnating
and cloying nature. It is contraindication in excess conditions with Dampness and Phlegm. As a consequence of these contraindications it is often used in combination with Chen Pi or Sha Ren to offset it’s stagnating nature and to protect the Spleen and Stomach and promote digestion.
The herb is Shu Di Huang (Rehmannia glutoinosa) - Chinese Foxglove.