Polygalae Radix
Aliases：Yaorao; Jiyuan; Jiwǎn; Xiaocao; Xicao; Xian'ercha; Xiaocaogen; Shenshacao.
Yuanzhi (Thinleaf Milkwort Root; Polygala Root) is the name of a traditional Chinese medicine. It is the dried root of Polygala tenuifolia Willd. or Polygala sibirica L., plants in the genus Polygala of the family Polygalaceae. It is an authenticated variety of the National Administration of Traditional Chinese Medicine's Terminology Standardization and Promotion Project and is recorded in Shennong Bencao Jing (The Divine Farmer's Materia Medica), Bencao Gangmu (Compendium of Materia Medica), Pharmacopoeia of the People's Republic of China, Zhonghua Bencao (Chinese Materia Medica), and other herbal works.
Efficacy & Actions
Calms the spirit and improves intelligence; restores communication between the Heart and Kidney; resolves Phlegm; reduces swelling.
Indications
Insomnia with profuse dreams due to disharmony between the Heart and Kidney; forgetfulness and palpitations with fright; clouded spirit; ineffective coughing with sticky phlegm; sores, ulcers, and toxic swellings; breast swelling and pain.
Modern Pharmacology
Modern pharmacological studies have confirmed that Thinleaf Milkwort Root (Polygala Root) possesses the following significant pharmacological activities: Neuroprotective and cognitive-enhancing effects: Polygala saponins, as the main bioactive constituents of Thinleaf Milkwort Root, exhibit multi-target neuroprotective effects in the treatment of neurological diseases. Through pharmacological actions such as anti-inflammation, anti-apoptosis, anti-oxidative stress, autophagy regulation, improvement of synaptic plasticity, and inhibition of ferroptosis, they effectively intervene in the pathological processes of Alzheimer's disease, depression, Parkinson's disease, and insomnia. Thinleaf Milkwort Root possesses neuroprotective and cognitive function-improving pharmacological effects. Antidepressant effect: The extract of Thinleaf Milkwort Root alleviates chronic unpredictable mild stress-induced depressive behaviors in rats by regulating the NLRP3 inflammasome and NF-κB pathway. 3,6′-Disinapoyl sucrose (DISS) in Thinleaf Milkwort Root possesses antidepressant activity, and its mechanism involves increasing the expression of noradrenergic-regulated plasticity genes and neurotrophic factors in the hippocampus, as well as regulating the hypothalamic-pituitary-adrenal (HPA) axis. The triterpenoid saponin Yuanzhi-1 isolated from Thinleaf Milkwort Root acts as a triple monoamine reuptake inhibitor and exhibits antidepressant-like activity. Sedative-hypnotic and anticonvulsant effects: Thinleaf Milkwort Root possesses sedative-hypnotic and anticonvulsant pharmacological effects. Polygala saponins have central inhibitory effects and can increase the content of the neurotransmitter GABA in the brain, thereby producing a sedative-hypnotic effect. The saponin constituents in Thinleaf Milkwort Root can block excessive neuronal discharge, reducing or preventing epileptic seizures. Expectorant and antitussive effects: Thinleaf Milkwort Root possesses expectorant and antitussive pharmacological effects. The saponin constituents in Thinleaf Milkwort Root can dilute respiratory secretions and promote their expulsion, thereby achieving an expectorant effect. Honey-processed Thinleaf Milkwort Root has superior antitussive and expectorant effects compared with the raw and licorice-processed products. Anti-ischemic stroke effect: The root extract of Thinleaf Milkwort Root exhibits significant anti-ischemic effects in OGD/R cell models and tMCAO rats, exerting protective effects by inhibiting HMGB1-driven neuroinflammation. Anti-non-alcoholic fatty liver disease effect: The extract of Thinleaf Milkwort Root significantly suppresses the PGE2 inflammatory pathway through the COX2 and PERK-eIF2α-ATF4 pathways, thereby exerting anti-inflammatory and antioxidant effects, improving lipid metabolism, and delaying the progression of non-alcoholic fatty liver disease. Renal protective effect: The water extract of Thinleaf Milkwort Root (with tenuifoliside A as a key compound) significantly reverses gentamicin-induced acute kidney injury in mice. Antibacterial effect: Thinleaf Milkwort Root significantly inhibits Gram-positive cocci, Shigella dysenteriae, Salmonella typhi, and other bacteria. Antiarrhythmic effect: Thinleaf Milkwort Root possesses antiarrhythmic pharmacological activity. Anti-aging and brain-protective effects: Thinleaf Milkwort Root possesses anti-aging and brain-protective pharmacological activities. Note: The above pharmacological findings are largely derived from modern experimental studies on root extracts of Thinleaf Milkwort Root and constituents such as Polygala saponins, oligosaccharide esters, and xanthones. Dedicated systematic pharmacological research on Thinleaf Milkwort Root is still ongoing. Traditional actions and indications should remain the primary basis for use.
Ingredients
The root of Thinleaf Milkwort (Polygala tenuifolia) mainly contains the following active constituents: Triterpenoid saponins (principal active constituents): Tenuifolin Onjisaponin A, B, C, D, E, F, and G Polygalacic acid Senegenin Polygalasaponin XXVII Oligosaccharide esters: 3,6′-Disinapoyl sucrose (DISS) Tenuifoliside A, B, and C Sibiricose A5 and A6 Tenuifoliose H, I, L, and Q Tenuifoliside Xanthones: Polygalaxanthone Ⅲ Polygalaxanthone Ⅳ–Ⅺ Sibiricaxanthone B 7-O-Methylmangiferin Lancerin 1,2,3,6,7-Pentamethoxyxanthone, among others Phenones: Tenuiphenone A, B, C, and D Others: Alkaloids (1-butoxycarbonyl-β-carboline, etc.) Flavonoids Organic acids Volatile oils (containing 16 compounds, 14 identified) Note: More than 140 compounds have been isolated and identified from Thinleaf Milkwort root, mainly saponins, oligosaccharide esters, and xanthones. Polygala saponins have complex structures; more than one hundred have been reported in the literature, and the basic aglycone of most Polygala saponins is tenuifolin.
Usage & Dosage
Oral use: Decocted in water, 3–10 g; or steeped in alcohol, or taken in pills or powders. External use: Appropriate amount, ground into powder and mixed with wine for topical application.
Contraindications
Use with caution in individuals with excess Heat or internal exuberance of Phlegm-Fire. Use with caution in individuals with gastric ulcer or gastritis. Excessive doses of Thinleaf Milkwort Root may cause symptoms such as nausea and vomiting. Thinleaf Milkwort Root contains various alkaloids that are difficult for the digestive tract to break down, and large doses may increase the burden on the digestive system. Use with caution during pregnancy. Contraindicated in individuals with Yin deficiency and hyperactive Fire, or with Fire in the Heart and Kidney. Contraindicated in individuals allergic to Thinleaf Milkwort Root. Do not overdose.
Selected Formulas
For endemic goiter (Jiangxi Chinese Herbal Medicine) Take unripe persimmon, crush to extract juice, and take orally. For tung oil poisoning (Jiangxi Herbal Medicine Manual) Take 2–3 persimmons or dried persimmon cakes orally. For chronic bronchitis (dietary formula) Take 5 good-quality dried persimmon cakes and cut into thin strips. Rinse 150g of japonica rice and soak in water for 30 minutes. Put both into a cooking pot, add an appropriate amount of water, bring to a boil over high heat, then reduce to low heat and simmer into congee. Add white sugar or honey to taste. Eat as a side dish. Actions: strengthen the spleen and stop diarrhea. Effective for chronic diarrhea and deficiency dysentery, weak stomach with poor appetite, infantile spleen-deficiency diarrhea, and chronic enteritis.
Medicinal Parts
Dried root.
Selection & Storage
Dried material should be stored in a well-ventilated, dry place. Protect from moisture and insect damage. Airtight storage is recommended. Avoid direct sunlight. Processed products (licorice-processed Thinleaf Milkwort Root and honey-processed Thinleaf Milkwort Root) should be sealed and stored in a cool, dry place. Protect from moisture and insects. Xiaocao (the aerial parts) should be sealed and stored in a well-ventilated, dry place.
