Bi Xie (Rhizoma Dioscoreae Hypoglaucae)

What Is Bi Xie

Bi Xie commonly known as Rhizoma Dioscoreae Hypoglaucae is the rhizome of Dioscorea collettii var. hypoglauca Palibin, Dioscorea spongiosa Thunb., or Dioscorea futschauensis Uline ex R.Kunth, which is a perennial twiner belonging to the family Dioscoreaceae. The first one is also called Fen Bi Xie, while the other two are called Mian Bi Xie (Rhizoma Dioscoreae Spongiosae). It is a relatively practical and common Chinese herbal medicine, which first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (about 100 BC).

There are about 631 species of Dioscorea, which are mainly distributed in tropical and warm temperate regions. Currently, only a few species have been introduced into temperate regions. Some of these species are medicinal, such as D. nipponica, D. polystachya, D. collettii var. hypoglauca, D. spongiosa Thunb., and D. futschauensis Uline ex R.Kunth.

D. collettii var. hypoglauca is endemic to China. They are distributed in Henan, Anhui, Zhejiang, Fujian, Taiwan, Jiangxi, Hubei, Hunan, Guangdong, and Guangxi. They often grow on the edge of mixed forests or under sparse forests on the steep slopes of mountainsides, gentle slopes of valleys, or shady places near ditches at an altitude of 200 to 1,300 meters. They like light and grow well in deep, loose, fertile, highly permeable soil.

Dioscorea collettii var. hypoglauca Palibin

D. spongiosa Thunb. is mainly distributed in Zhejiang, Fujian, Jiangxi, southwestern Hubei, Hunan, northern Guangdong, and eastern Guangxi in China. They often grow in mountain sparse forests or thickets at an altitude of 450-750 meters.

D. futschauensis Uline ex R. Kunth. is distributed in southern Zhejiang, Fujian, Hunan, northern Guangdong, and Guangxi in China. They often grow in scrub and forest margins on mountain slopes, gully sides, or roadsides below 700 meters above sea level.

From autumn to winter, people gather the rhizomes of Dioscorea collettii var. hypoglauca Palibin, D. spongiosa Thunb., or D. futschauensis Uline ex R.Kunth, remove impurities and their fibrous roots, wash them with water, cut them into thin slices, dry them in the sun, and make them into Chinese herbal medicines.

Bi Xie contains dioscin, diosgenin, dioscin prosapogenin A, dioscin prosapogenin B, dioseptemloside A, dioseptemloside F, gracillin, diosgenin-3-O-β-D-glucopyranose, protodioscin, methyl protodioscin, furostanol saponins, pregnane saponins, cholestane saponins, β-sitosterol, daucosterol, stigmasterol, stigmasterol-3-O-β-D-glucoside, diarylheptanes, lignans, flavonoids, organic acids, amino acids, lipid compounds, polysaccharides, and tannins.

Generally, the mealy and fragile Fen Bi Xie with a light yellow edge on the new cross-section is preferred. The mealy Mian Bi Xie with a grayish-white to light grayish-brown cross-section and yellow-brown punctate vascular bundles is preferred.

According to the Chinese Pharmacopoeia, the medicinal property of Bi Xie is relatively neutral, with a bitter taste. It has a certain therapeutic effect on the pathological changes of the kidney and stomach meridians.

In traditional Chinese medicine, it is often used to remove dampness and clear away turbidness, dispel wind and remove pain, and treat turbid urine, gonorrhea, chyluria, leukorrhagia, chronic prostatitis, aching pain in the waist and knees, flaccid tendons and bones, limbs fatigue, hemiplegia, facial paralysis, numbness of limbs, rheumatic arthritis, rheumatoid arthritis, osteoarthritis, osteoporosis, hyperuricemia, gout, and hyperlipidemia.

There are more than 150 kinds of traditional Chinese medicine prescriptions containing it, such as Bi Xie Fen Qing Wan, Tian Ma Wan, and Gu Chi Wan.


  • Anti-fungus, inhibiting Malassezia furfur and Staphylococcus aureus in vitro [1].
  • Anti-inflammation, reducing monosodium urate-induced paw swelling in mice and monosodium urate-induced PGE2 and IL-1β levels in inflammatory exudates of mouse air sacs [2].
  • Increasing the pain threshold, prolonging the pain time of mice to thermal stimulation, and reducing the number of writhing in mice induced by acetic acid [2].
  • Removing dampness and clearing away turbidness, treating stranguria marked by chyluria.
  • Treating leukorrhagia caused by excessive dampness.
  • Dispelling wind and eliminating dampness, removing obstruction in channels to relieve pain, treating obstructive pain in the waist and knees, muscular spasms, disadvantageous flexion and extension of joints caused by wind-cold-dampness or wind-damp-heat.
  • Decreasing effect of Dioscin on serum uric acid level and enhancing effect on urate excretion were confirmed in hyperuricemia animal models [3].
  • Its total saponin significantly decreased the fasting blood glucose, glycosylated hemoglobin, urinary protein, serum creatinine, and blood urea nitrogen levels in streptozotocin-induced diabetic rats. It ameliorates glomerular and tubular pathological changes in diabetic rats [4].
  • Its furostanol saponin is cytotoxic against most cell lines from leukemia and solid tumors in the NCI’s (National Cancer Institute, USA) anticancer drug screen [5].
  • Its chloroform extract can reduce the serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels and increase high-density lipoprotein cholesterol levels in hyperlipidemia model rats.
  • The water extract of D. spongiosa can stimulate the proliferation of osteoblasts and inhibit the formation of osteoclasts [6]. In vivo experiments showed that its 90% ethanol fraction was effective on anti-osteoporosis using the ovariectomized (OVX) rats. Also, its 90% ethanol extract is effective on inhibiting glucocorticoid-induced osteoporosis in rats by improving the bone tissue metrology, BMC, and BMD as well as biomechanical indicators, and also repairing the microscopic changes of cancellous bones and trabecular bones [7].


  • It can be used in combination with Wu Yao (Radix Linderae), Yi Zhi Ren (Sharpleaf Galangal Fruit), and Shi Chang Pu (Rhizoma Acori Tatarinowii) to treat stranguria due to chyluria, turbid urine, and gonorrhea.
  • It can be used in combination with Zhu Ling (Polyporus), Bai Zhu (Rhizoma Atractylodis Macrocephalae), and Ze Xie (Rhizoma Alismatis) to treat leukorrhagia caused by excessive dampness.
  • It can be used in combination with Fu Zi (Radix Aconiti Lateralis Preparata), Wei Ling Xian (Radix Clematidis), and Du Huo (Radix Angelicae Pubescentis) to treat obstructive pain in the waist and knees, muscular spasms, disadvantageous flexion and extension of joints caused by wind-cold-dampness.
  • It can be used in combination with Huang Bai (Cortex Phellodendri), Ren Dong Teng (Caulis Lonicerae Japonicae), and Fang Ji (Radix Stephaniae Tetrandrae) to treat obstructive pain in the waist and knees, disadvantageous flexion and extension of joints caused by wind-damp-heat.
  • It can be used in combination with Rou Cong Rong (Herba Cistanche), Tu Si Zi (Semen Cuscutae), and Du Zhong (Eucommia Bark) to treat flaccid tendons and bones, soreness and weakness of the waist and knees, limbs fatigue, vertigo and tinnitus, spiritlessness and amnesia caused by kidney deficiency and damage of essence.

Side Effects

At present, there is no literature report that Bi Xie has toxic effects, and no data is showing that taking it at the prescribed dose can cause serious adverse reactions.

Precautions and Warnings

  • The dosage of Bi Xie should be controlled at 9-15g.
  • It can be made into decoctions, pills, capsules, or medicinal liquors.
  • People who are allergic to Bi Xie should not take it.
  • Patients with a deficiency of kidney-yin should not take it.
  • Patients with nocturnal emission and spermatorrhea should not take it.
  • Pregnant and breastfeeding women should take it under medical supervision.