encyclopedia

Skullcap

Scientific Names:
Scutellaria lateriflora Linnι. and related Scutellaria species [Fam. Labiatae]

Forms:
Dried herb or tincture made from above-ground parts of Scutellaria lateriflora and dried root of S. baicalensis

Traditional Usage:
– Anti-inflammatory

– Anxiety

– Epilepsy

– Heart Health Maintenance

– Inflammation

– Insomnia

– Muscle Spasms

– Nerve Pain

– Sedative

– Vascular Disorders

Overview:
Skullcap, Scutellaria lateriflora Linnι, S. baicalensis Georgi and other Scutellaria species [Fam. Labiatae], also known as Helmet flower, Hoodwort, Quarker Bonnet, Scutellaria, and Scullcap, is a perennial found in North America, Asia, and Europe. Scutellaria lateriflora is the species indigenous to North America and is believed to have sedative, anti-spasmodic, anticonvulsant, and anti-inflammatory properties. In folk medicine it has been used to treat epilepsy, chorea (movement disorders), hysteria, nervousness, and grand mal seizures. The Chinese species, S. baicalensis Georgi, has slightly different properties and is used as a remedy for inflammation, dermatitis, allergic diseases, hyperlipidemia, vascular disorders and heart health maintenance. Skullcap tea is also known to have antioxidant and antibacterial activity and inhibits lipid peroxidation in the liver. Flavonoids are the main active ingredient in skullcap, but it should be noted that knowledge of the chemical make up of skullcap is limited due to lack of sufficient studies. The claims surrounding skullcap’s sedative and anticonvulsant properties have yet to be substantiated. A clinical study on Chinese Scutellaria and its effect on cerebral thrombosis, cerebral embolism, and paralysis caused by stroke resulted in an 88% effective cure rate. However, skullcap can be adulterated with germander, Teucrium species, especially Teucrium canadense. A recent study of medicinal plants in the genus Scutellaria (S. galericulata, S. lateriflora and S. baicalensis; known collectively as skullcap) analyzed random DNA segments using nine accessions of the three species in an effort to distinguish between members of these three species. Dried aerial parts of two species, S. galericulata and S. lateriflora, are notoriously difficult to distinguish morphologically and so this study aimed to make identification easier. The method was deemed useful. Cluster analysis using the DNA fragments clarified the genetic relatedness of the species and was in good agreement with the taxonomic designations of the three species.

Active Ingredients:
Skullcap contains: flavonoids (apigenin, hispidulin, luteolin, scutellarein, scutellarin (bitter glycoside); iridoids (catalpol); volatile oils (limonene, terpineol [monoterpenes], d-cadinene, caryophyllene, trans-b-farnesene, b-humulene [sesquiterpenes]); other constituents include lignin, resin, tannin. The related species S. baicalensis is reported to contain baicalein, baicalin, chrysin, oroxylin A, skullcapflavone II, and wogonin.

Limited information has been documented regarding the constituents of S. lateriflora, although various related Scutellaria species have been investigated. The department of Pharmaceutical Botany, Faculty of Pharmacy at Hacettepe University in Turkey isolated the previously known neo-clerodane scutalpin J Scutellaria orientalis subsp. sintenisii together with a new diterpenoid, scutenisin, whose structure was established as (13R*)-6alpha,7beta-diisobutyryloxy-4alpha,18;8beta, 13-diepoxy-19-hydroxy-neo-clerodan-15,16-olide by spectroscopic means. [Ezer N, Akcos Y, Rodrguez B. 1998. Neo-clerodane diterpenoids from Scutellaria orientalis subsp. sintenisii. Phytochemistry. 1998 Nov 20; 49(6): 1825-1827; Tomimori T et al. 1985. Studies on the constituents of Scutellarian species VI. On the flavonoid constituents of the root of Scutellaria baicalensis Georgi (5). Quantitative analysis of flavonoids in Scuterllaria roots by high-performance liquid chromatography. Yakugaku Zasshi 1985; 105: 148-55].

Suggested Amount:
Dried herb: 1-2 grams or by infusion three times daily

Liquid Extract: (1:1 in 25% alcohol0 2-4 ml three times daily

Tincture: (1:5 in 45% alcohol) 1-2 ml three times daily

Drug Interactions:
None known.

Contraindications:
Skullcap should be avoided during pregnancy and lactation. Although it was once given to women to eliminate afterbirth and promote menstruation, there is not enough information on the pharmacological activity and toxicity of the drug to justify its use.

Side Effects:
Excessive use or overdose may cause giddiness, stupor, confusion, and seizures. Hepatotoxic reactions have been reported after ingesting preparations containing skullcap. Adulteration of skullcap herb by germander (Teucrium chamaedrys) has been documented. Several cases of hepatitis have been associated with germander (Teucrium chamaedrys). [Larrey D et al. 1992. Hepatitis after germander (Teucrium chamaedrys) administration: another instance of herbal medicine toxicity. Am Call Physns 1992; 117: 129-32]. Chinese skullcap may cause pneumonia in susceptible persons. A 53-year-old Japanese man with recurrent interstitial pneumonia was referred to medical researchers. The patient had taken a traditional herb medicine, otsu-ji-to, before the onset of pneumonia. A provocation test for each herbal ingredient contained in otsu-ji-to revealed that the pneumonitis had been induced by ou-gon (scullcap). Lymphocytosis with the CD8+ T-cell subset predominance was found in the bronchoalveolar lavage fluid and lymphocytic alveolitis was noted in the transbronchial lung biopsy specimen after the

provocation test. Ou-gon, or scullcap, should be included in the list of drugs with definite causal association with pneumonitis. [Takeshita K, Saisho Y, Kitamura K, Kaburagi N, Funabiki T, Inamura T, Oyamada Y, Asano K, Yamaguchi K. 2001. Pneumonitis induced by ou-gon (scullcap). Intern Med. 2001 Aug; 40(8): 764-8].

References:

Kimura Y et al. Studies on Scutellariae radix; IX. New component inhibiting lipid peroxidation in rat liver. Planta Med 1984; 50: 290-5.

Kubo M. et al. Scutellariae radix. X. Inhibitory effects of various flavonoids on histamine release from rat peritoneal mast cells in vitro. Chem Pharma Bull 1984; 32: 5051-4.

Peigen X, Keji C. Recent advances in clinical studies of Chinese medicinal herbs. 1. Drugs affecting the cardiovascular system. Phytotherapy Res 1987; 1: 53-57

Yan M, Gao X, Liu L, Chen F, Yang H, Song H, Wang X, Yi H. 1998. [Observation on inhibitory effect of Coptis alone and its combination with Scutellaria and Liquorice on the growth of Staphylococcus aureus]. Zhongguo Zhong Yao Za Zhi. 1998 Jun; 23(6): 375-7, Chinese.

Hosokawa K, Minami M, Kawahara K, Nakamura I, Shibata T. 2000. Discrimination among three species of medicinal Scutellaria plants using RAPD markers. Planta Med. 2000 Apr; 66(3): 270-2.