Herbs & Botanicals
Sophora Root (ku shen)
What is sophora? What is it used for?
Sophora root is the root of sophora flavescens Ait., a hardy deciduous shrub native to China, Japan, Korea and Russia. The shrub can reach a height of approximately five feet, with leaves of various shaves, greenish-yellow flowers, and brown seed pods that contain small seeds. The root, which is used in herbal preparations, ranges between four and 12 inches in length and one-half to an inch in diameter, and is usually brown and curved, with small cracks or ridges on its outer surface. The roots are prepared by bundling them and cutting them cross-wise into slices, then allowing them to dry in the sun.
Sophora root has been used for centuries in traditional Chinese medicine. It is considered to have bitter and cold properties, and is associated with the Heart, Liver, Stomach, Large Intestine and Urinary Bladder meridians. Its functions are to clear heat and dry dampness, to promote urination, to disperse wind, and to stop itching.
Sophora root contains a wide range of biologically active components, the most well-known of which is matrine. Laboratory studies have shown that matrine can dilate blood vessels, stabilize some heart arrhythmias and increase cardiac output; however, at large doses, matrine can be toxic. Animal studies suggest that other substances in sophora root can stimulate the nervous system, treat asthma, and slow the degeneration of liver cells and fibrous tissue in the liver.
Sophora root can be used both internally and externally. Internally, it can kill some parasites, treat dysentery and some bacterial infections, and promote the production of urine. Externally, it can be applied to the skin (usually with other herbs such as dictamnus and cnidium) to treat scabies, eczema and other skin ailments.
How much sophora root should I take?
The amount of sophora root to be taken depends on the condition being treated. For internal uses, the generally recommended dose is 3-10 grams daily, taken as part of a decoction; however, some practitioners have recommended much higher doses (30-60 grams) to treat arrhythmia. Sophora root is often combined with other herbs as part of a larger formula to treat specific conditions.
What forms of sophora root are available?
Dried, sliced sophora root can be found at some herbal shops and Asian markets. Sophora root is also available as a powder or pill (usually as part of a larger formula), or a decoction (either with water or alcohol).
What can happen if I take too much sophora root? Are there any interactions I should be aware of? What precautions should I take?
Large amounts of matrine (a component in sophora root) may cause toxicity in some individuals. In addition, because of its effects on the heart and central nervous system, it should not be taken by patients on heart or blood pressure medications. It should never be taken in conjunction with black hellebore root. It is also contraindicated in patients diagnosed with weakness and cold in the spleen and stomach. As always, make sure to consult with a licensed health care provider before taking sophora root or any other herbal remedy or dietary supplement.
- Editorial Committee of Chinese Materia Medica. State Drug Administration of China. Chinese Materia Medica. Shangai: Science and Technology Press, 1998.
- Chen WZ, et al. Matrine's effect on experimental rat liver fibrosis. Journal of Second Military Medical College 1996;17(5):424-426.
- Li YH, et al. Ku shen's effect of reinforcing the middle warmer and strengthening the stomach. Journal of Guangzhou College of TCM 1992;9(2):83-85, 92.
- Zha L, et al. Ku shen total alkaloids' effects on coronary blood flow. Pharmacy Bulletin 1984;19(12):58.
- Zhou B, et al. Ku shen total alkaloids' effects on fibrin and fibrinogen degradation product-induced blood vessel cell damage and proliferation, and peritoneal macrophages' release of IL-1. Journal of Pharmacy 1999;34(5):342-344.