Medicinals
dù zhòng / 杜仲 / 杜仲 / eucommia [bark]
Latin pharmacognostic name: Eucommiae Cortex
Alternate English names:
Alternate Chinese names: 石思仙 shí sī xiān;
Origin: Plant
Use: medicinal
Category: Supplementing agents / Yáng-supplementing agents
Properties: Sweet; warm.
Channel entry: liver and kidney channels.
Indications:
- Supplements the liver and kidney; strengthens sinew and bone: Painful aching or limp weak lumbus and knees, impotence, and frequent urination.
- Quiets the fetus: Bleeding in pregnancy, stirring fetus, and habitual miscarriage from
liver-kidney vacuity and insecurity of thoroughfare (chōng) and controlling (rèn) vessels. - Modern applications: Dù zhòng has been found to lower blood pressure.
- For hypertensive elderly patients with a kidney vacuity pattern, it is often combined with yín yáng huò (淫羊藿 Epimedii Herba, epimedium), sāng jì shēng (桑寄生 Taxilli Herba, mistletoe), and niú xī (牛膝 Achyranthis Bidentatae Radix, achyranthes [root]). For patients with ascendant hyperactivity of liver yáng and/or liver fire, it is often combined with xià kū cǎo (夏枯草 Prunellae Spica, prunella [spike];), jú huā (菊花 Chrysanthemi Flos, chrysanthemum [flower]), and huáng qín (黄芩 Scutellariae Radix, scutellaria [root];).
Dosage & Method:
Oral: 10–15g in decoctions. Some sources indicate that the stir-fried form is more effective medicinally.
Warning:
Use with care in yīn vacuity with effulgent fire.
Product Description:
This bark comes in flat strips with a slight curl, 1–6 mm thick, with pale grayish-brown cork bearing longitudinal wrinkles and furrows, and transverse lenticels. Thicker areas of cork are often partly removed, leaving a flat, brown surface. The inner surface has a smooth texture and is dark, purplish, or blackish brown in color. This bark is brittle, but when broken the parts are held together by silvery, extensible filaments. The decocting pieces are sections with multiple cuts allowing the filaments to be stretched. When char-fried in with brine, they are brownish black in color.
Quality:
Best when hard and dry, with rubbery threads that do not easily break.
Product Area:
Sìchuān, Guìzhōu, Húběi.
Etymology:
The name dù zhòng 杜仲, according to Lǐ Shí-Zhēn, is named after Dù Zhòng, who attained enlightenment after ingesting this agent. Several alternate names such as sī lián pí 丝连皮, sī mián pí 丝绵皮, and zhǐ sī pí 扯丝皮, refer to the filaments (sī 丝) that hold the broken bark together.