Botanical Name:Scutellaria lateriflora, Lamiaceae
Common names: Skullcap, Scullcap, Blue Pimpernel, Madweed, Hoodwort, Mad-dog
Similar species: S.galericulata
Plant description: Skullcap is a herbaceous perennial with a four-angled, smooth stem with many branches, attaining a height of between 30 cm to 160 cm when mature. Skullcap has small hairless leaves, borne on petioles about 5-8 cm long, the leaves themselves about 2.5-5 cm long by 1-1.5 cm wide,ovate, with a rounded base, an acute tip, the leaf margin acutely serrate. The flowers are borne in axillary racemes that arise from the leaf axils, flowers on only one side. They are pale blue, blossoming in summer, comprised of a fused upper and lower sepal, the upper sepal with a raised appendage that looks like a helmet or hood.The petals are fused into a two-lipped corolla, with four stamens. The flower gives way to four small nutlets.
Habitat, ecology and distribution: The various species of Scutellaria have a wide distribution through the milder temperate regions of North America, Europe and Siberia. S. lateriflora and the rather similar Marsh Skullcap (S.galericulata) tend to prefer wet habitats and rich soils, in meadows, marshes, stream banks, lakeshores, wet ditches and grassy clearings. Much of the Skullcap on the market is commercially grown.
Part used: Aerial parts.
History: The name for this genus name is derived from the Latin scutella, meaning ‘a little dish,’ suggested by the shape of the calyx.The common name of ‘Skullcap’ describes its usage as a treatment for disorders of the central nervous system, suggested by the shape of the flowers when looking down upon them from above, which looks somewhat like a skull.
Constituents: There is little constituent information for Skullcap herb and many sources appear to include constituent information for the root of the Chinese S. baicalensis, which is a decidedly different medicinal herb. Among what could be considered as important constituents in S. lateriflora are the flavonoids apigenin, hispidulin, luteolin, and scutellarein, as well as the bitter glycoside scutellarin. Skullcap also contains an essential oil, lignin, resin, tannin, some miscellaneous alkanes, minerals such as calcium, potassium and zinc, as well as a wax (Newall et al 1996, 239; Duke 1992; Bergner 1997, 245).
Medical Research: None.
Toxicity: There is no actual toxicity stated for Skullcap, but herbalists have long recognized that in very large doses the herb can produce sensory disturbances such as peripheral numbness and tingling, as well as confusion, giddiness and a temporary loss of consciousness. Skullcap is frequently adulterated or substituted at source with other species of the Lamiaceae, including the hepatotoxic Germander (Teucrium) (Newall et al 1996, 239). The degree to which this affects the marketplace is not well known, but many herbalists feel that adulteration is very common, and care should be taken when purchasing this her commercially.
Herbal action: nervine relaxant, nervine trophorestorative, antispasmodic, nutritive
Indications: exhaustion, spasm, convulsion, nervous irritability, neuralgia, muscle spasm, anxiety, nervousness, addiction withdrawa
Contraindications and cautions: Skullcap may interact with or even potentiate the activity of pharmaceutical preparations that act on the central nervous system, including tranquilizers, antipsychotics and antiepileptics.
Medicinal uses: It appears that Skullcap continues to be a much “neglected herb,” just as it was once considered by William Cook (1869). Although little or nothing of its virtues are recognized in science and medical research, it continues to be a popular mainstay for many herbalists. Skullcap is an important nervine trophorestorative, with generally relaxing or sedating properties, but in a few individuals can promote mental exhilaration. In most cases however, and in suitable doses, Skullcap acts as an agent to relax the nervous system. Cook considered Skullcap specific to “…restless and wakeful conditions, with feebleness…and…all forms of nervousness with fatigue or depression” (1869). This traditional indication for Skullcap seems particularly germane in our modern society of over stimulation and lack of rest, but unlike other relaxing agents, Skullcap generally promotes sedation without any “…shade of narcotism” (Cook, 1869). To this end Skullcap is often used along with more sedating botanicals such as Valeriana and Escscholzia, Avena and Passiflora in physiological opioid addiction, and with Lobelia to satiate nicotine cravings. The amount of Skullcap used in such cases should err on the high end of the dosage range in order to be effective, often until some of its sensory effects, such as minor visual distortions and peripheral numbness begin to be displayed. If the situation is more a case of psychological addiction, smaller doses should prove to be more effective. Skullcap is also highly valued in neuralgia and visceral pain, used in cardiac weakness and irregularity, when these symptoms are “…due to feebleness with agitation, but not connected with acute or sub-acute inflammatory excitement” (Cook 1869). It is often used in formulation with diffusive remedies such as Lobelia and Actaea in muscle spasm and seizures, and with Caulophyllumin dysmenorrhea. Skullcap can be thought of as being a ‘cooling’ remedy, reducing the passions and fires that drive the body towards states of anger and irritability, but acts through nervous function only and does not influence other inflammatory mediators such as eicosanoids. Thus for chronic inflammation Skullcap should be considered as only an adjunct to more sophisticated approaches. It is mentioned as an important remedy in the prevention and treatment of delirium tremens (Felter and Lloyd 1893), and when combined with Lycopus may be beneficial in Grave’s disease. In digestive disorders Skullcap exerts a mild tonic property, favouring the normalization of autonomic balance through its nervine properties. In teething children Skullcap may be effective to reduce nervous irritability and pain, administered to the mother or directl as an infusion-soaked cloth or dilute tincture. Felter and Lloyd state that the warm infusion has a mild diaphoretic property, whereas the cold infusion exerts its activity as a digestive tonic (1893).In pulse diagnosis the character of Skullcap is noted by an irregular pulsation. Most herbalists prefer the fresh plant extract, or at the very least a dry maceration of the recently dried plant material. Skullcap loses its properties upon boiling.
Pharmacy and dosage:
• Fresh Plant Tincture: fresh aerial parts, 1:2. 95% alcohol, 3-20 gtt, 2.5-15 mL
• Dry Plant Tincture: recently dried herb, 1:4, 40% alcohol, 3-20 gtt, 2.5-15 mL Infusion: recently dried herb, 1:20, 50-300 mL
• Powder:recently dried herb, 500-3000 mg