Sophora Flavescens Root (Ku Shen)

Though literally translated as bitter ginseng in English, Ku Shen has nothing to do with ginseng at all. Actually it is another completely different Chinese herb, which is better known as sophora flavescens or sophora root in common name and Radix Sophorae Flavescentis in Latin name. Likewise, it has different medicinal properties and health benefits. This herb was first mentioned in “Shen Nong’s Herbal Classic” and viewed as one of the medium-grade drugs. That means it may be poisonous but can heal sickness and tonify deficiency when used appropriately. As a matter of fact, it is a good medicine for clearing heat, removing dampness, hair growth, and killing insects, which makes it a really popular option in the treatment of skin diseases and gynecological diseases.

What is sophora flavescens?

Medicinally it mainly refers to the dried root of Sophora flavescens Ait., which is a plant in the family Leguminosae. And it has a few other names, including sophora flavescens radix, lightyellow sophora root, Flavescent Sophora Root, Root of Light Yellow Sophora, Sophora Flavescens Root, and more. It is produced all over China and harvested during spring and autumn. After the digging, for better medicinal quality it should remove the head and small fibrous root, wash clean, and dry immediately or dry after slicing when it is still fresh. And it is usually used raw. And now it is consumed in various forms, like sophora flavescens supplement, extract, tea, capsules, powder, etc.

This plant is a dwarf-shrub, 50 to 120cm high. Root is cylindrical and yellow in appearance. Stems are herbaceous, green, and with yellow hair when young and irregular longitudinal groove. Pinnately compound leaves are odd, alternate, and with linear stipules underneath; blade is from 20 to 25cm long and with pubescent axis; leaflets are 5 to 21, with a short handle, ovate-elliptic to oblong-lanceolate, rounded or blunt-tipped apex, rounded or wedge-shaped base, and entire margin. Racemes are acrogenous, short-haired, 10 to 20cm long; bracts are linear; Flowers are yellowish white; calyx is bell-shaped and slightly oblique; corolla looks like butterfly. Pods are linear; apex is with a long beak. Seeds usually are 3 to 7, black, nearly spherical, and with constriction between seeds. It flowers from May to July and fruits from July to September. Habitats are places exposed to the sun, including grassy hillside, plains, roadsides, sandy soil and red soil.

Sophora root mainly contains alkaloids, flavonoids, quinones, and triterpenoid saponins. Alkaloids contain matrine, oxymatrine, sophoridine, sophoranol, sophoramine, etc. Flavonoids contain kushenol, kuraridin, kuraridinol, kurarinol, neokurarinol, norkurarinol, isokurarinone, kurarinone, and more. Triterpenoid saponins include sophoraflavoside Ⅰ, Ⅱ, Ⅲ, Ⅳ, soyasaponin I, and so on. Quinones are kushequinone A and others.

Sophora flavescens benefits

Xiao Feng San, also known as Eliminate Wind Powder, is one famous formula for treating skin diseases. Many veteran doctors of TCM love to use it for mild skin diseases, or even complex chronic psoriasis. Many medical cases from them prove that this is one of effective herbal formula, in which sophora root is that ingredient plays an important role. But keep in mind it won’t work unless in large dosage. In addition to skin diseases, clinically it also treats insomnia, diarrhea, high fever, irregular heartbeat, hot hands and feet, urinary tract infection, hair loss, Hepatitis B Virus (HBV) etc. Facts have justified that this is an herb with tons of health benefits.

Modern sophora root pharmacology

1. It has obvious inhibition on heart, which can slow the heart rate, weaken the myocardial contractility, and reduce cardiac output;
2. This herb itself, matrine, and kurarinone have anti-arrhythmia effects;
3. It injection has rapid and long-lasting effect on aconitine-induced arrhythmias. And it also has antihypertensive effect;
4. Its decoction has inhibition on Mycobacterium tuberculosis, Shigella, Staphylococcus aureus, Escherichia coli, and a variety of skin fungus;
5. Its decoction can induce diuresis, reduce inflammation, prevent allergies, make people calm down, relieve asthma, eliminate phlegm, elevate white blood cell count, and fight cancer.

Selected herbal remedies on sophora root

The Chinese Materia Medica reveals that Ku Shen is bitter in flavor and cold in medicinal properties and it goes to 6 meridians of liver, kidney, large intestine, small intestine, bladder, and heart. Basic functions are clearing heat, drying dampness, dispelling wind-evil, and killing insects. Vital sophora flavescens uses and indications include damp-heat dysentery or diarrhea, hematochezia, jaundice, inhibited urination, edema, morbid leucorrhea, vaginal itching, scabies, leprosy, pruritus, noxious dampness, and sores and ulcers. Recommended dosage is from 3 to 10 grams in decoction, pills, or powder.

1. Ku Shen Di Huang Wan from Wai Ke Da Cheng (Compendium of External Medicine). In this recipe, it is equipped with Sheng Di Huang (Rehmannia) to treat blood in the stool and anal fistula due to damp-heat.

2. Lu Bai San from Wei Sheng Bao Jian (Precious Mirror for Defending Life). In this formula, this single herb is ground into powder and applied with sesame oil to relieve pain in empyrosis.

3. Shen Jiao Wan from Ji Feng Pu Ji Fang (Universal-Relief Prescriptions from Jifeng). In this prescription, it works with Zao Jiao (Gleditsia), Jing Jie (Schizonepeta), etc. for curing itchy skin.

4. Xiao Feng San from Wai Ke Zheng Zong (Orthodox Exogenous Illnesses). It combines with Fang Feng (Saposhnikovia Divaricata), Schizonepeta, etc. to deal with rubella itching.

5. Shen Jiao Tang from Wai Ke Zheng Zhi Quan Shu (Complete Treatise on Surgery). It joins Hua Jiao (Sichuan Peppercorns) for the treatment of scabies.

Sophora flavescens side effects and contraindications

It is classified as a poisonous plant in the database of China Botanical Illustration. Both sophora flavescens seeds and roots are considered toxic (poisonous). Poisoning is mainly related to the nervous system and symptoms include salivation, rapid breathing, accelerated pulse, gait instability, convulsions, and even death due to respiratory depression in severe cases. So, small dosage is highly recommended since too large of a dose of this herb may lead to unexpected adverse reactions. As for drug interactions, it clashes with Li Lu (Veratrum). TCM wise, Ku Shen shouldn’t be used in the case of deficiency-cold in spleen and stomach.