Scutellaria lateriflora - Skullcap

Description

There are over 300 species of Scutellaria worldwide, 133 of which grow in the Americas. Scullcap is a perennial herb with rhizomes. It has a slender square stem 1 to 8 cm tall. The flowers are blue, rarely pink or white, and have a helmet-like appearance. S. galericulata has a solitary flower on the leaf axil whereas S. lateriflora (preferred by most practitioners) has axillary racemes. The leaves are oblong-lanceolate to ovate.

Part Used

Herb

Constituents

The major constituents in scullcap include a volatile oil, scutellarin, a bitter glycoside (yielding scutellarin upon hydrolysis), tannins, lignin, fat, resins, sugar and cellulose. Oriental scullcap (S. barbata and S. baicalensis) has been shown to contain a large number of flavones including baicalein, baicalin, wogonin, and skulcapflavone II.(1-9)

Mode of Action

The calming effect of scullcap has been attributed to scutellarin.(10) The herb has been used for neuralgia, hiccoughs, insomnia and nervous disorders. Scullcap has shown an anti-acetylcholine and antihistamine effect on isolated guinea pig ileum, as well as inhibiting norepinepherine-induced contraction in guinea pig vas deferens. Heart rate has been shown to be reduced.(11-16)

A 70% methanol extract of the whole root of the species with flavonoid present showed anti-arthritic and anti-inflammatory action. It has been shown to inhibit arachidonates in rat leukocytes. This could have great significance for many inflammatory diseases.(17)

Chinese Scullcap (S. baicalensis) root has shown significant anti-allergenic and anti-inflammatory properties.(18,19)

Therapeutic Action

Antispasmodic, nervine, tonic, antipyretic, anaphrodisiac and a slight astringent.

Energetics

Traditional Chinese

Scullcap (herbage of a related species S. barbata) is pungent with a neutral property. It cleanses heat, removes toxins, disperses stagnancy, controls bleeding and pain.(20) The root of Scutellaria baicalensis is bitter and cold, entering the Heart, Lung, Gall Bladder, Small Intestine, and Colon. The action is to quell fire and clear heat, especially in the upper burner, drain damp heat, calms fetus, preventing spontaneous miscarriages.(21,22)

Other

Holmes lists scullcap as bitter, a bit astringent, cold and dry, having secondary qualities of relaxing, restoring and stimulating while stabilizing movement. It enters the Heart and Kidney meridians while influencing the heart, kidney, urogenital organs, autonomic and central nervous system, brain and spine. The organism is air.(23) Tierra lists scullcap as bitter and cool, and influences the Heart and Liver.(24)

Folklore

Scullcap`s major influence is on the central and sympathetic nervous systems. It has been used for hydrophobia (rabies, thus one of its name ‘mad dog` scullcap), St. Vitus` Dance, neuralgia, insomnia, excitability, restlessness, rickets, headaches, hiccough, incessant coughing, hypertension, snake bites, to promote menstruation and for poisonous bites.(25-27) It is noted in James` Herbal (1743, Vol.2).(28) The Cherokee and Iroquois used scullcap to induce emesis, and for a variety of problems including gynecological ailments, as an abortifacient, and as an antidiarrheal.(29)

Dosage (30-32)

Powder - 15 - 30 grains
Infusion - 3 oz
Tincture - 10 - 40 drops
Fluid extract - 1/4 tsp

Toxicity and Contraindications

Overdose has been shown to cause CNS stimulation, irregular pulse, confusion and hyperreflexia.(33) No fatal toxicity has been associated with this herb.

Official Recognition and Medical References
PDR for Herbal Medicine - p. 1128
References

1. Kimura, Y., et al., Studies on scutellariae radix; XII. Effects of various flavonoid on arachidonate metabolism in leukocytes, Plant Medica #2, 132-36, 1985.
2. The British Pharmaceutical Codex 1934. The Pharmaceutical Press, London, 1934, p. 942.
3. Spoerke, D.G., Herbal Medications, Woodbridge Press Publ. Co., Santa Barbara, CA, 1980. p. 158.
4. Veninga, L. and Zaricor, B.R., Goldenseal/Etc.: A Pharmacognosy of Wild Herbs, Ruka Publications, Santa Cruz, CA, 1976. p. 164.
5. The Merck Index 5th ed., Merck & Co. Inc., Rahway, NJ, 1940, p. 494.
6. Gathercoal, E.N. and Wirth, E.H., Pharmacognosy, Lea & Febiger, Phila., PA, 1936. p. 619.
7. Youngken, H.W., Textbook of Pharmacognosy, Blakiston, Toronto, 1950. p. 734.
8. Grieve, M., A Modern Herbal, Jonathan Cape, London, 1931, p. 724.
9. Duke, J.A., Handbook of Medicinal Herbs, CRC Press Inc., Boca Raton FL, 1985. p. 440.
10. Heinerman, J., The Science of Herbal Medicine, BiWorld Publ., Orem UT, 1979. p. 124.
11. Kato, M., et al., Pharmacological studies on saiko prescription. I & II Effect of constituent crude drugs of saiko prescriptions and its every fractional extract on isolated smooth muscles, Yakugaku Zasshi 102(4), 371-87, 1982.
12. Kurnakov, B.A., Pharmacology of skullcap, Farmakologia I Tosikologia 20(6), 79-80, 1957.
13. Shibata, S. et al., Studies on the constituents of Japanese and Chines crude drugs. III Antispasmodic action of flavonoid and anthraquinones, Oriental Med. 80(5), 620-623, 1960.
14. The British Pharmaceutical Codex 1934. Ibid.
15. Heinerman, J., The Science of Herbal Medicine, Ibid.
16. Grieve, M., Ibid.
17. Kimura, Y., et al., Ibid.
18. Hsu, H.Y., Chen, Y.P., et al., Oriental Materia Medica: a concise guide, Oriental Healing Arts Institute, Long Beach, CA, 1986, p. 230-231.
19. Medi Herb Professional Newsletter; No 34 & 35 July Aug 1993
20. Hsu, H.Y., Chen, Y.P., et al., Ibid.
21. Hsu, H.Y., Chen, Y.P., et al., Ibid.
22. Bensky, D. and Gamble, A., Chinese Herbal Medicine: Materia Medica, Eastland Press, Seattle, WA, 1986, p. 107-109.
23. Holmes, P., The Energetics of Western Herbs (2 vols.), Artemis Press, Boulder, CO, 1989, p. 447-449.
24. Tierra, M., Planetary Herbology, Lotus Press, Santa Fe, NM, 1988, p. 354-355.
25. Willard, T.W., Textbook of Modern Herbology, c.w. Progressive Publishing Inc., Calgary, AB, Can., 1988, p. 245.
26. Duke, J.A., Ibid.
27. Grieve, M., Ibid.
28. Crellin, J.K. and Philpott, J., Herbal Medicine: Past and Present (Vol. II), Duke University Press, London, 1990, p. 396.
29. Moerman, D.E., Medicinal Plants of Native America, University of Michigan Museum of Anthropology, Technical Reports, Number 19, Ann Arbor, Michigan, 1986, Vol.1, p. 448.
30. The British Pharmaceutical Codex 1934. Ibid.
31. Grieve, M., Ibid.
32. Culbreth, D.M.R., A Manual of Materia Medica and Pharmacology, Eclectic Medical
Publications, Portland OR , 18xx (Repr. 1983). p. 511.
33. Spoerke, D.G., Herbal Medications, Ibid.