Common Name: Chinese Skullcap
Botanical Name: Scutellaria baicalensis Georgii
Part Used: The root primarily, however, the above-ground parts are also used.
Constituents: Flavonoids: baicalin, baicalein, wogonin, wogonside, and more than 35 others.
Baicilin is the dominant flavonoid varying from 12-17% in the root.
Sesquiterpenes in the volatile oil: limonene, terpineol, carophyllene, and others.
Historical Notes: Scutellaria baicalensis, a member of the mint family, is known as “huang qin” in Chinese, which translated literally means yellow gold. This is an accurate description of the yellow root that has been used for centuries to “cleanse heat, dry moisture, and remove toxins.”1 In Traditional Chinese Medicine (TCM) this would describe a patient with fever, perspiration, red face, dislike of heat, desire for cold drinks, and inability to sleep.2 The plant is now being assessed by science for its ability to reduce inflammation, as well as its potential as an anti-viral, anti-bacterial, and anti-tumor agent.
Chinese or Baikal skullcap (Scutellaria baicalensis) is native to China, Korea, Russia and Mongolia. Baikal skullcap was first mentioned as a medicinal plant in ancient Chinese medical texts roughly 2,000 years ago and was commonly used by Mongol and Buryat shamans living around lake Baikal in the southern region of Siberia, hence its common name.
Pharmacology: Most of the activity of S. baicalensis is certainly due to its high flavonoid content. Baicalin is the dominant flavonoid in the root and is easily extracted in 50% ethanol. Upon hydrolysis, the aflavone baicalein and glucuronic acid are generated.3 Intestinal microflora are primarily responsible for hydrolysis. A human study was conducted to detect plasma levels of baicalin and baicalein after oral administration. No baicalin was detected in the serum, however, its aglycone baicalein was found to peak twice. There was an initial rise between two and four hours and another peak at twelve hours. The second peak was due to the further breakdown of baicalin by intestinal microflora. Baicalein was still detectable in the plasma 24 hours after the initial dose.4
The anti-inflammatory effects of S. baicalensis are due to selective inhibition of lipoxygenase by baicalein, while the whole root has mild inhibitory action upon cycloxygenase.5 Leukotriene B4 (LTB4) is a powerful attractant and activator for neutrophils and plays a key role in a number of inflammatory conditions of the pulmonary system. An in-vitro study was conducted using baicalein on human alveolar macrophages from patients with a variety of respiratory illnesses. Baicalein was shown to inhibit production of LTB4 in a dose-dependent manner with 100 M of baicalein inhibiting LTB4 synthesis by 80%.6 This same concentration of baicalein was also shown to inhibit leukotriene C4 production up to 75% in another in-vitro study.7
S. baicalensis is a potent inhibitor of lipid peroxidation with one in-vitro study demonstrating that baicalin inhibited lipid peroxidation three times more than quercitin and more than 375 times more than vitamin E. Baicalein was found to a superior free-radical scavenger when compared to vitamin E but was not as potent as quercitin.8 Japanese researchers believe that part of the anti-inflammatory activity of the root may be due to inhibition of sialidase, an enzyme implicated in a number of inflammatory disorders.9
In-vitro studies suggest that S. baicalensis may be of benefit in the treatment of gout. At 10 M, baicalein inhibited xanthine oxidase by 64 % compared to allopurinal (a standard gout medication) which showed 43% inhibition at the same concentration.10
Baicalein inhibits type I and II hypersensitivity reactions, making it useful in the treatment of allergies, allergic dermatitis, and asthma.11
Baicalein inhibits platelet aggregation, while baicalin inhibits thromboxane synthetase in vitro.12
Animal studies reveal that during the stress response, insulin, glucose, and ACTH are normalized with the administration of the whole root.13 This poses the question of adaptogenic potential with the use of Chinese skullcap.
S. baicalensis has been shown to inhibit a number of viruses including Epstein-Barr14 and influenza-A.15 The flavonoids have demonstrated strong inhibition of reverse transcriptase and in-vitro inhibition of HIV infection.16 Clinical benefit in humans is yet to be evaluated. In-vitro research indicates that baicalin helps to repair damaged DNA,17 possibly making this herb of benefit to those with cancer. A study of patients with lung cancer who were receiving chemotherapy found that the extract of S. baicalensis enhanced hematopoiesis and increased levels of circulating precursors of erythroid and granulocyte colony stimulating units.18 Another study of patients receiving chemotherapy for lung cancer also showed an increase in serum immunoglobulins19
S. baicalensis may play a role in the treatment of asthma. Narrowing of the bronchial airways occurs as inflammatory cells from the circulation migrate into the lungs resulting of vasodilation, increased vasopermeability, and increased adhesiveness of leukocytes to endothelial cells. Leukotrienes are central to this response. The flavonoids in Chinese skullcap are effective inhibitors of lipoxygenase, thus preventing the synthesis and release of LTC4 and LTB4. Many children have asthma with a strong allergic component with inflammation resulting from hypersensitivity-type reactions. Once again, S. baicalensis may be of some benefit through its inhibition of type I and II hypersensitivity reactions.
Chinese skullcap is often used by herbalists as part of a treatment protocol for inflammatory joint disease. With the roots ability to prevent lipid peroxidation, inhibit lipoxygenase and to a lesser extent, cycloxygenase, it is certainly biologically plausible that S. baicalensis may be of benefit, especially for those suffering from gouty arthritis.
The traditional use of this plant certainly included fever and respiratory infection. The root has activity against a number of viruses, thus along with its anti-inflammatory activity it is probably a useful agent for the treatment of respiratory illness. The potential for S. baicalensis to be of benefit for HIV is preliminary but intriguing.
Patients who are undergoing chemotherapy may benefit from the use of S. baicalensis if anemia and/or leukopenia occur.
Contraindications: TCM practitioners contraindicate S. baicalensis for conditions characterized by excess cold or deficient heat, represented by symptoms of lethargy, clear discharge, or night sweats.
Adverse Effects: Large doses of tincture may cause tremor, confusion, and giddiness20 but this is not seen with typical usage. Many herb books list skullcap as causing liver toxicity. Scutellaria laterifolia, the herb used primarily by western herbalists, has occasionally been adulterated with Teucrium spp., which has clearly been linked with hepatotoxicity. Two cases of pneumonitis and one case of hepatotoxicity have been reported in the Japanese literature related to the ingestion of Sho-saiko-to, a herbal formula containing S. baicalensis, however, the causative agent has not been identified.21
There may be some interaction with cyclosporine at doses of 1-2 grams per kg (in rat study). Caution should be exercised
Dosage & Preparation:
The average oral intake of S. baicalensis is from 1-2 grams per day of the dried root. It is available on the market as dried root, capsules, and alcoholic extracts. Dose for tincture (1:5) is 4 ml. TID. Standardized products are also available.
1 Hsu HY. Oriental Materia Medica: A Concise Guide. Oriental Healing Arts Institute, Long Beach, CA, 1986.
2 Kaptchuk TJ. The Web That Has No Weaver: Understanding Chinese Medicine
. Congdon & Weed, New York
, NY, 1983.
3 Tang W, Eisenbrand G. Chinese Drugs of Plant Origin: Chemistry, Pharmacology, and Use in Traditional and Modern Medicine. Springer-Verlag, New York, NY, 1992.
4 Nishioka Y, Kyotani S, et al. Influence of time of administration of a Shosaiko-To extract granule on blood concentration of its active constituents. Chem Pharm Bull
5 Alcarez MJ, Ferrandiz ML. Modification of arachidonic metabolism by flavonoids. J Ethnopharmacol 1987; 21:209-229.
6 Yasuo T, Kakuta Y, et al. Effects of Qing-Fei-Tang (Seihai-to) and baicalein, its main component flavonoid, on lucigenin-dependent chemiluminescence and leukotriene B4 synthesis of human alveolar macrophage. Am J Chin Med 1988; 16:145-54.
7 Butenko IG, Gladtchenko SV, Galushko SV. Anti-inflammatory properties and inhibition of leukotriene C4 biosynthesis in vitro by flavonoid baicalein from Scutellaria baicalensis
GEORGI roots. Agents Actions
8 Hara H, Sakamoto T, Ohtaka H, et al. Effects of baicalein and alpha-tocopherol on lipid peroxidation, free radical scavenging activity and 12-O-tetradecanoylphorbol acetate-induced ear edema. Eur J Pharmocol 1992; 221:193-98.
9 Nagai T, Yamada H, Otsuka Y. Inhibition of mouse liver sialidase by the root of Scutellaria baicalensis. Planta Med 1989; 55:27-29.
10 Chang W, Lee Y, et al. Inhibitory effects of flavonoids on xanthine oxidase. Anticanc Res 1993; 13:2165-170.
11 Nagai HK, Osuga A, Koda A. Inhibition of hypersensitivity reactions by soluble derivatives of baicalein. Jap J Pharmacol
12 Wang SR, Guo ZQ, Liao JZ. Experimental study on effects of 18 kinds of Chinese herbal medicines for synthesis of thromboxane A2 and PGI2. Chung Kui Chung His I Chieh Ho Tsa Shih 1993; 13:167-70. (Abstract reviewed, original article is in Chinese).
13 Udintsev SN, Krylova SG, Konovalova ON. Correction by natural adaptogens of hormonal-metabolic status disorders in rats during the development of adaptation syndrome using functional tests with dexamethasone and ACTH. Biull Eksper Biol I Medits 1991; 112:599-601. (Abstract reviewed, original article is in Russian).
14 Konoshima T, Kikumai M, et al. Studies on inhibitors of skin tumor production. Inhibitory effects of flavonoids from Scutellaria baicalensis
on epstein-barr virus activation and their anti-tumor-promoting activities. Chem Pharm Bull
15 Nagai T, Miyaichi Y, et al. In-vivo anti-influenza virus activity of plant flavonoids possessing inhibitory activity for influenza virus sialidase. Antivir Res 1989; 12:99-110.
16 Li BQ, et al. Inhibition of HIV infection by baicalin – a flavonoid compound purified from Chinese herbal medicine. Cell Mol Biol Res 1993; 39(2): 119-24.
17 Higashitanai A, Tabata S, et al. Plant saponins can affect DNA recombination in cultured mammalian cells. Cell Struct Funct 1989; 14:617-24.
18 Goldberg VE
, et al. Dry extract of Scutellaria baicalensis
as a hemostimulant in antineoplastic chemotherapy in patients with lung cancer. Eksp Klin Farmakol
1997; 60:28-30. (Abstract)
19 Smolianinov DA, et al. Effect of Scutellaria baicalensis extract on the immunologic status of patients with lung cancer receiving antineoplastic chemotherapy. Eksp Klin Farmakol 1997; 69:49-51.
20 Nagai T, Yamada H, Otsuka Y. Inhibition of mouse liver sialidase by the root of Scutellaria baicalensis
. Planta Med
21 Daibo A, Yoshida Y, et al. A case of pneumonitis and hepatic injury caused by a herbal drug (Sho-saiko-to) Jap J Thorac Dis 1992; 30:1583-88. (Abstract reviewed, article in Japanese.)
Copyright Tieraona Low Dog, MD. 2008