Rhododendri Daurici Radix
Aliases：Xing'an Rhododendron Root and Dazixiang Root. (These are alternative names for Manshanhong Root, i.e., Daurian Rhododendron Root.)
Manshanhong Root is a traditional Chinese medicinal material. It is the dried root of Rhododendron dauricum L., a plant belonging to the genus Rhododendron of the family Ericaceae. It is recorded in the Dongbei Changyong Zhongcaoyao Shouce (Handbook of Commonly Used Chinese Herbal Medicines in Northeast China).
Efficacy & Actions
Arrests dysentery.
Indications
Enteritis and dysentery (including acute bacillary dysentery).
Modern Pharmacology
Antitussive effect: The decoction of Manshanhong has a significant antitussive effect, with the main active component being germacrone. Expectorant effect: The aqueous solution and the active component farrerol exhibit significant expectorant effects. Antiasthmatic effect: The alcohol extract solution can antagonize bronchospasm, exhibiting an antiasthmatic effect. Antibacterial effect: The decoction and alcohol extract exhibit inhibitory effects against Staphylococcus aureus, Staphylococcus albus, Streptococcus hemolyticus (group A), Pseudomonas aeruginosa, and other bacteria. Anti‑inflammatory and analgesic effects: Manshanhong exhibits good anti‑inflammatory and analgesic effects. Diuretic and antihypertensive effects: Manshanhong has diuretic effects and also lowers blood pressure. Cardiotonic effect: Appropriate doses of Manshanhong preparations exhibit digitalis‑like cardiotonic effects. Clinical studies have shown that Manshanhong Root achieves a cure rate of up to 90% in the treatment of acute bacillary dysentery.
Ingredients
Flavonoids: farrerol, hyperoside, isohyperoside, quercetin, myricetin, taxifolin, etc. Volatile oils: germacrone (also known as dalmacrone), juniper camphor, menthol, α‑/β‑/γ‑eudesmol, etc. Coumarins: scopoletin, umbelliferone, etc. Phenolic acids: vanillic acid, rhododendrol, etc. Others: hydroquinone and trace amounts of grayanotoxin. Researchers have isolated seven active compounds from Manshanhong, namely farrerol, myricetin, quercetin, taxifolin, umbelliferone, hyperoside, and juniper camphor.
Usage & Dosage
For oral administration: decoct in water, 9–15 g. For fresh herb: The dosage may be increased appropriately. In the treatment of acute bacillary dysentery, use 250 g (approximately half a jin) of fresh Manshanhong Root, add 1500–2000 ml of water, decoct for 1–2 hours, and take the extracted juice.
Contraindications
Adverse reactions may occur with large doses: sudden drop in blood pressure, slowed heart rate, and various arrhythmias. Use with caution in the elderly: Toxic reactions mostly occur in elderly patients; therefore, dosage should be strictly controlled. Use with caution in patients with abnormal liver or kidney function. Use with caution in patients with liver disease. Contraindicated during pregnancy: This herb is toxic and is contraindicated in pregnant women. Use with caution in patients with coronary heart disease or pulmonary heart disease: Manshanhong contains grayanotoxin, which has certain cardiac toxicity. Possible neurological symptoms include dry mouth, nausea, vomiting, etc., but these are usually mild in degree.
Selected Formulas
For acute bacillary dysentery (empirical formula) Take 250g of fresh Manshanhong (Rhododendron dauricum) root (washed and sliced), add 1500-2000ml of water, decoct for 1-2 hours, and extract the liquid. Adults: 150-200ml each time; children (3-5 years old): 50ml each time. Take 3 times daily. For enteritis and dysentery (empirical formula) Take 15g of Manshanhong root, decoct in water and drink.
Medicinal Parts
Dried root.
Selection & Storage
Store in a cool, dry place, protected from moisture and heat.
