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![]() St. John's Wort (Hypericum Perforatum
L.): A Review © Christopher Hobbs
L.Ac., A.H.G. (Excerpted from
HerbalGram) Introduction Among the many medicinal herbs used throughout the long history of Occidental culture, St. John's wort, Hypericum perforatum L., has always been and still is of great interest. From the time of the ancient Greeks down through the Middle Ages, the plant was considered to be imbued with magical powers and was used to ward off evil and protect against disease. As a practical folk-remedy, it has been used widely to heal wounds, remedy kidney troubles, and alleviate nervous disorders, even insanity. In the last thirty years Hypericum perforatum has undergone extensive clinical and laboratory testing. The present article reviews the plant's botany, history of use, chemistry, pharmacology, pharmacodynamics, medical uses, and preparations. Botany Taxonomy and Description St. John's wort is a member of the genus Hypericum, of which there are 400 species worldwide. There is some disagreement as to the plant's family, some placing Hypericum in the segregate family Hypericaceae, while others place it in the family Guttiferae. However, most researchers now think that the morphological and chemical differences of the two families are insufficient to justify separating them (1,2). The plants are described as glabrous perennials, erect and usually woody at the base. The ovate to linear leaves are sessile, opposite, and well-supplied with translucent glandular dots. The regular flowers have five short, subequal, entire, imbricate, basally connate sepals, and five persistent-withering yellow petals. The ovary is superior, capsicular, and three-styled. Stamens are many, arranged in bundles of threes, and the flowers are profuse, arranged in branched cymes which bloom from June until September. In the absence of insect pollination, apomixis commonly occurs. St. John's wort should not be confused with rose of sharon (H. calycinum), a common ornamental ground-cover in the United States. Rose of sharon flowers and leaves are much larger than those of St. John's wort (though interestingly, anti-biotic substances have been extracted from H. calycinum that are similar in activity to substances in H. perforatum (3). Range and Habitat Table 1. Summary of Constituents and Activity from Hypericum perforatum
The hyperin and tannin content of H. perforatum is higher at growth temperatures above 14 degrees C. (tannin, 15.06% of dry weight) than below (13.42%). Both hyperin and rutin content is higher in dry conditions (1.25% and 2.32% respectively) than wet conditions (no figure given and 1.89%, respectively). Hyperin content is highest at 7pm (84). Total tannin content is highest when the buds are forming, just prior to flowering, in June (85,86). Higher amounts of flavonoids, including rutin, quercetin, and hyperin occur in plants of northern slopes with few generative shoots (87). Flavonoid content (rutin, hyperin, quercetin, and quercitrin) is highest in the leaves of St. John's wort, and is at maximum concentration during full bloom. In the flowers, the content of flavonoids is highest at the start of flowering, falling sharply during flowering (88). St. John's wort (flowers) had the highest content of flavonoids (11.71%) of any of 223 species tested (89). Pharmacology Extracts of the flowering tops of Hypericum perforatum have shown a variety of effects in the laboratory, including psychotropic activity, wound and burn-healing activity, bactericidal effect against pathogens in pyelitis and cystitis, anti-viral effects, sunscreen activity (disputed), antidepressive activity, and diuretic, anthelmintic, and mildly uterotonic activity (90, 91, 92). Although much more work needs to be done to validate the use of St. John's wort for the many uses it finds in clinical and common practice, there are a few laboratory studies which corroborate its use for some of these conditions and point the way for further research. Following is a summary of the laboratory work that has been conducted on the pharmacological effects of St. John's wort extract or oil. Anti-depressive and Psychotropic Activity Among the most common psychiatric illnesses today are depression, mania, (abnormal elation with irritability), bipolar affective disorder, characterized by swings between depression and mania, and schizophrenia. One of the best-known (but contoversial) theories hypothesizes that depression is caused by deficiency or decreased effectivness of norepinephrine and serotonin, acting as nerve-impulse transmitting substances (neurotransmitters), in particular nerve pathways. One method for treating depression uses the monoamine oxidase (MAO) inhibitors which retard one of the enzymes responsible for monoamine (a precursor) breakdown, increasing the concentration of neurotransmitters in the central nervous system (93, 94). Because of St. John's wort's history of use for psychiatric conditions, it was tested for MAO inhibiting activity. Suzuki, et al. (1984), in an international effort, first demonstrated that xanthones, common in the Guttiferae (the family of St. John's wort) and the Gentianaceae (Gentian family), inhibit both type A and B monoamine oxidase. Among these is the compounds isogentisin, which has been found in some species of Hypericum, but not H. perforatum (95, 96). A further study by the same group found that hypericin from H. perforatum irreversibly inhibits type A and B MAO in vivo. The authors stress, however, that although this study is suggestive, no definite conclusion can be drawn yet regarding St. John's wort's antidepressant activity (97). A standardized (hypericin) extract of H. perforatum has been tested in various animal models generally used for determining antidepressant activity, and has been found to enhance the exploratory activity of mice in a foreign environment, extended the narcotic sleeping time dose-dependently, and has shown reserpine antagonism and decreased aggressive behavior in socially isolated male mice (98). Muldner and Zoller (1984), in a clinical trial with 6 depressive women, 55-65 years old, measured smetabolites of noradrenaline and dopamine in the urine, and found that after taking a standardized hypericin extract, there was a significant increase in 3-methoxy-4-hydroxyphenylglucol, a marker for the beginning of an antidepressive reaction. The same research team, working with 15 women taking a standard hypercin extract, demonstrated an improvement in symptoms of anxiety, dysphoric mood, loss of interest, hypersomnia, anorexia, depression (worse in the morning), insomnia, obstipation, psychomotoric retardation, and feelings of worthlessness. They reported no side-effects (99). Wound and Burn Healing In a number of studies St. John's wort extracts have demonstrated anti-bacterial and wound-healing activity. For instance, two widely prescribed Russian preparations of Hypericum, novoimanine and imanine, have been tested for Staphylococcus aureus infection in vivo and in vitro, and been found to be more effective than sulfonilamide (100, 101, 102). Hyperforin, a bicyclic tetraketone from H. perforatum, is reported to be a main antibiotic constituent of novoimanine (103). One German patent mentions that an ointment containing an extract of St. John's wort flowers shortened healing time of burns and showed antiseptic activity (104). According to the report, first degree burns healed in 48 hours when treated with the ointment, while second and third degree burns healed without keloid (a type of scar tissue) formation three times faster than burns treated by conventional methods. Other reports include that a freeze-dried St. John's-wort extract suppressed inflammation and leukocyte infiltration in vivo (105), and that St. John's wort oil has been used in commercial products as a sun screen. However, reports of its efficacy in this latter regard are contradictory (106, 107). Anti-viral Effects International interest increased in St. John's wort after researchers from New York University medical center and the Weizmann Institute of Science in Israel demonstrated that two compounds from the plant strongly inhibit a variety of retroviruses in vitro and in vivo (108). Several points bear citing from their report:
Clinical Applications Clearly, the potential scope of clinical application of St. John's wort is extensive. However, if one narrows the focus down to those activities that are most mentioned, such as anti-bacterial, anti-phlogistic, diuretic, and anti-depressive, specific clinical applications become more restricted. In modern European medicine, St. John's wort extracts are included in many over-the-counter and prescription drugs for mild depression, and have clinical application for bed-wetting and nightmares in children. The extract is included in diuretic preparations, and the oil is taken internally by the teaspoon to help heal gastritis, gastric ulcers, and inflammatory conditions of the colon (using a retention enema) (110). The oil is also used extensively in burn and wound remedies, externally. Table 2, taken from the German Health Department's official monograph on St. John's wort (1984), summarizes the current clinical applications of the plant (105,106). Table 2. Clinical Indications for St. John's wort Herb source: flowers of Hypericum perforatum, "gathered during the time of blooming or of the dried parts above the ground, as well as their preparations, in effective dosages." Clinical applications: Internally: "psychovegetative disturbances, depressive states, fear and/or nervous disturbances. Oily hypericum preparations during dyspeptic disturbances." Externally: "Oily hypericum preparations for the treatment or after treatment of sharp or abrasive wounds, myalgias (muscular pain) and first degree burns." Contraindications: "None known." Side effects: "Photosensitization is possible, especially in light skinned people." Interference with other drugs: "None known." Dosage schedule: Average daily dose recommended is 2-4 grams of the powdered herb, or 0.2-1.0 g hypericin as a powdered extract. Method of use: "Cut or powdered plant, liquid and solid forms for oral administration. "Liquid and semi- solid forms for external use." Effects: Mild anti-depressant action (monoamineoxidase [MAO] inhibitor), oily preparations have antiphlogistic activity. "Diuretic activity,...direct effect on smooth musculature." Toxicity Besides its long history of use as a medicinal plant, St. John's wort is also known as a photosensitizing plant that can cause sickness and even death in grazing animals (when large amounts are eaten), particularly cattle, sheep, horses, and goats, but also rabbits and rats111. This toxic activity of St. John's wort was first noted in the literature by Cirillo (1787), and since then, there have been many papers published, and the effect mentioned numerous times (112). The plant, however, does not seem to be a major threat to livestock, because the first symptoms of Hypericum intoxication includes loss of appetite, which makes the absorption of the photodynamic pigment, hypericin, self-limiting (113). In the case of Hypericum toxicity, the compound hypericin is absorbed from the intestine and concentrates near the skin. When the skin of the animal is exposed to sunlight, an allergic reaction takes place. Oxygen is necessary for the photodynamic hemolysis, leading to tissue damage. In the absence of sunlight, a reaction will not occur, and the compound does not show particular toxicity. (114, 115) This first type of reaction is called 'primary photosensitization' (116). Another, more serious type, is secondary photosensitization, where the liver and other internal organs can be damaged (117). Cattle appear to be more sensitive to the phototoxicity of hypericin than sheep. In one test with cattle, a single dose of 1 g per kg bodyweight of dried Hypericum showed no photosensitization or changes in liver enzymes, but 3-4 g did. If humans were as sensitive to hypericin as cattle, this dose would correlate to 59 gms for a 130 lb individual. Importantly, hypericin does not seem to be accumulative. (118) Although there have been a considerable number of studies published demonstrating the phototoxicity of hypericin in various animal species (119, 120), a thorough search by this writer brings to light no evidence that there has ever been a case involving human toxicity. Some authors recommend caution when using large quantities of St. John's wort extract for medicinal uses, particularly for people with fair skins, who should not expose themselves to strong sunlight during Hypericum therapy (121). Judging by the available literature, a very moderate dose, up to 4 g of the dried herb, 30 ml of the 1:5 tincture (40% EtOH), or 240 grams of the 1:5 powdered extract per day (standardized to 0.125% hypericin), should not pose a problem, if sunlight restriction is followed (122, 123), especially given the widespread use of H. perforatum extracts in Europe. One major product is recommended by the manufacturer to be taken as 40 mg tablets (1-2 tablets, 3 times a day). Preparations Hypericin was more effectively extracted with glycol and sunflower seed oil when the moisture content of the herb was between 50 and 70%, and 2-7 times higher at 70 degree C. than at 20 degree C. The menstruum was saturated after 12 hours and 24 hours respectively, but it took 3-4 extractions to exhaust the herb (124). The total extraction in one hour of hypericin with ethanol was not dependent on water content of the herb. The authors conclude that ethanol is the most suited menstruum for the extraction of dried material (125). Freshly air-dried herb was moistened to 70-72% moisture and extracted at 70 degree at 1:7 with sunflower seed oil. The total content of hypericin was 2.5 mg%, and extracting the marc with ethanol could increase the content to 3.32 mg% (a 25% increase)(126). Hypericin content of a juice of H. perforatum and a powdered extract dropped by 14% during 1 year, and the dry extract remained stable, when stored at 20 degree C. When stored at 60 degree C., the hypericin content dropped 33%, 33%, and 47% from a powdered extract, tablets, and liquid juice, respectively (127). In one extensive study, up to 80% of the hypericin was destroyed by drying of the fresh plant in sunlight (128). For this reason, modern herbalists generally grind the fresh tops of Hypericum and immediately macerate them in olive oil or sunflower seed oil. The oil is then pressed and filtered after two weeks, and should be stored in amber bottles away from heat and light. An alcoholic tincture is made in the same way, macerating the fresh, ground tops in 70% ethyl alcohol and 30% distilled water. St. John's wort is currently official in the pharmacopeias of Czeckoslovakia, Poland, Roumania, and Soviet Union (129). Identification and Adulteration For identification of cut and sifted material from the commercial drug market, note the two opposite ridges on the stems. These are prominent, and an important character in differentiating different Hypericum species (see Fig. 1). Ideally, the commercial drug should consist mostly of flowering tops, but in common practice the whole above-ground plant with a considerable quantity of stem may be present. Flowers that are present should consist of 70-90% (or more) with immature capsules, otherwise the plants may have been harvested too late in the season. The hypericin content declines immediately after anthesis (flower maturity and pollination). The leaves, when observed with a 10X hand lens, should be characterized by many punctate glands, clearly distinguishable by holding them up to a light source. The flowers will all contain fragments of the persistent dried petals, which may have red glands (appearing black) around the perimeter. The taste (and smell) of St. John's wort is characteristicly slightly sweet, bitter, and astringent. A commercial oil or tincture of Hypericum should be vivid, almost fluorescent red. If the preparation is pale red to pink, the hypericin content, and thus the quality of the product, is suspect. Several methods are given in the literature for the TLC and HPLC identification of hypericin (130, 131, 132, 133, 134, 135, 136, 137, 138), and Katalin et al (1982) report on the histological examination of St. John's wort leaves (139). Since tannins play a role in the therapeutic action of St. John's wort extracts, standardization with this fraction has been recommended (liquid extract containing 1% tannins) (140). Literature Review: An earlier review (1969) covers the history, development and photodynamic effect, chemical constituents, synthesis of hypericin, pharmacology and uses with 127 references (in German) 141. 1. Robson, N.K.B. 1977. Bull. Br. Mus. (Nat. Hist.), Botany 5:293. 2. Taskhtajan, A.L. 1980. Bot. Rev. 46: 225. 3. Shakirova, K.K., et al. 1970. "Antimicrobial properties of some species of St. John's wort cultivated in Uzbekistan," Mikrobiol. Zh. (Kiev) 32: 494-7 (CA 74: 34570d). 4. Hickey, M. & C. King. 1981. 100 Families of flowering plants, Cambridge University Press, Cambridge. 5. Wichtl, M. 1986. "Hypericum perforatum L. --Das Johanniskraut", Zeitschrift fur Phytotherapie 3: 87-90. 6. Campbell, M.H., et al. 1979. "Effect of time of application of herbicides on the long-term control of St. John's wort (Hypericum perforatum var. angustifolium)," Aust. J. Exp. Agric. Anim. Husb. 101: 746-8. 7. Pickering, C. 1879. Chronological History of Plants, Little, Brown & Co., Boston. 8. Jones, W.H.S. 1964. Pliny--Natural History v. VI: 8, 53. Harvard University Press, Cambridge. 9. Bailey, L.H. 1930. The Standard Cyclopedia of Horticulture, Macmillan, London. 10. Fernie, W.T. 1897. Herbal Simples, John Wright & Co., Bristol. 11. Jaeger, E.C. 1972. A Source-Book of Biological Names and Terms. Charles C. Thomas, Springfield, IL. 12. Vickery, A.R. 1981. "Traditional uses and flolklore of Hypericum in the British Iles", Economic Botany 35: 289-295. 13. Fernie, Herbal Simples. 14. Gunther, R.T. 1933. The Greek Herbal of Dioscorides, Hafner Pub. Co. (1968). 15. Pickering, op cit. 16. Vickery, op cit. 17. Alleyne, J. 1733. A New English Dispensatory, Tho. Astley, London. 18. Pratt, A. 1898. The flowering plants, grasses, sedges, and ferns of Great Britain, Frederick Warne & Co., London. 19. Vickery, op cit. 20. Gerard, J. 1633. The Herbal. Revised and enlarged by T. Johnson, reprinted by Dover Publications, NY (1975). 21. Culpeper, N. 1847. The Complete Herbal, Thomas Kelly, London. 22. Fernie, op cit. 23. State Historical Society of Wisconsin. 1944. Pharmacopoeia Londinensis of 1618 reproduced in facsimile, Madison. 24. Hill, J. 1808. The Family Herbal, C. Brightly & T. Kinnersley, Bungay. 25. Greene, T. 1824, The Universal Herbal, Caxton Press, London. 26. Fernie, op cit. 27. Moerman, D.E. 1986. Medicinal Plants of Native America. University of Michigan Museum of Anthropology, technical reports, number 10, Ann Arbor. 28. Vogel, V. 1970. American Indian Medicine, University of Oklahoma Press, Norman. 29. Griffith, R.E. 1847. Medical Botany, Lea & Blanchard, Philadelphia. 30. King, J. 1876. The American Dispensatory, 10th ed., Wilstach, Baldwin & Co., Cincinnati. 31. Felter, H.W. & J.U. Lloyd. 1898. King's American Dispensatory, 18th ed., reprinted by Eclectic Medical Publications, Portland, OR. 32. Lust, J. 1974. The Herb Book. Bantam, NY. 33. Moore, M. 1979. Medicinal Plants of the Mountain West, Museum of New Mexico Press, Sante Fe. 34. Kitanov, G.M. & K.F. Blinova. 1987. "Modern state of the chemical study of species of the genus Hypericum." Chemistry of natural compounds 23: 151-66. 35. Brockmann, H., et al. 1974. "Zur isolierung und konstitution des pseudohypericins," Tetrahedron Lett. 23: 1991-4. 36. Dorossiev, I. 1985. "Determination of flavonoids in Hypericum perforatum," Pharmazie 40: 585-6. 37. Mathis, C. & G. Ourisson. 1963. "Etude chimio-taxonomique du genre Hypericum," Phytochemistry 2: 157-171. 38. Okpanyi, S.N. & M.L. Weischer. 1987. "Experimental animal studies of the psychotropic activity of a Hypericum extract," Arzneim.-Forsch 37: 10-13. 39. Meruelo, D., et al. 1988. "Therapeutic agents with dramatic antiretroviral activity and little toxicity at effective doses: Aromatic polycyclic diones hypericin and pseudohypericin," Proc. Ntl. Acad. Sci. 85: 5230-34. 40. Kitanov, G. 1983. "Determination of the absolute configuration of ctechins isolated from Hypericum perforatum," Farmatsiya (Sofia) 33: 19-22 (CA 99:50290j). 41. Wichtl, op cit. 42. Derbentseva, et al. 1972. "Effect of tannins from Hypericum perforatum on influenza viruses," Mikrobiol. Zh. (Kiev) 34: 768-72. 43. Karryev, M.O. & N.F. Komissarenko. 1980. Izv. Akad. Nauk Turkm. SSR, Ser. Biol. Nauk 1980: 52-7. (CA 93: 182809w). 44. Dorossiev, I, op cit. 45. Stoyanova, A., et al. 1987. "Thin-layer chromatography of extracts of Hypericum perforatum," Farmatsiya 1: 8-13 (CA 107:205272q). 46. Hoelzl, J. & E. Ostrowski. 1987. "St. John's wort (Hypericum perforatum L.) HPLC analysis of the main components and their variability in a population," Dtsch. Apoth. Ztg. 127: 1227-30 (CA 107:112686). 47. Berghoefer, R. & J. Hoelzl. 1987. "Biflavonoids in Hypericum perforatum. Part 1. Isolation of 13,II8- biapigenin," Planta Med. 53: 216-17. 48. Koget, T.A. 1972. "Determination of the amount of quercitrin in Hypericum perforatum," Khim. Prir. Soedin. (2): 242-3 (CA 77:45514b). 49. Maksyutina, N.P. & T.A. Koget. 1971. "Polyphenols from the grass Hypericum perforatum and the preparation novoimanin," Khim. Prir. Soedin. 7: 363-7 (CA 75:115923u). 50. Holzl, J. & E. Ostrowski. [d.m.]. "Analysis of the essential compounds of Hypericum perforatum," Planta Medica [v.m.]: 531. 51. Vasil'chenko, et al. 1986. "Analgesic action of flavonoids of Rhododendron luteum Sweet, Hypericum perforatum L., Lespedeza bicolor Turoz. and L. hedysaroides (Pall.) Kitag," Rastit. Resur. 22: 12-21 (CA 104:142140k). 52. Dittmann, J., et al. 1971. "Normalizing glucose metabolism in brain tumor slices by hyperoside," Arzneim.-Forsch. 21: 1999-2002. 53. National Academy of Sciences. 1975. "Herbal Pharmacology in the People's Republic of China," N.A.S., Washington. 54. Vasilchenko, E.A., et al. 1986. "The analgesic effect of flavonoids of Rhododendron luteum Sweet, Hypericum perforatum, Lespedeza bicolor Turoy and L. hedysaroides (Pall)," Kitaz. Rastit. Resur. 22: 12-21. 55. Nielsen, M. & P. Arends. 1978. Phytochemistry 17: 2040. 56. Suzuki, O., et al. 1984. Planta Med. 50: 272. 57. Hostettmannn, K. & H. Wagner. 1977. Phytochemistry 16: 821. 58. Denisova-Dyatlova, O.A. & V.I. Glyzin. 1982. Glyzin. Usp. Khim. 51: 1753. 59. Karryev, op cit. 60. Ayuga, C. & Rebuelta, M. 1986. "Comparative study of phenolic acids of Hypericum caprifolium Boiss. and Hypericum perforatum L.," An. R. Acad. Farm. 52: 723-7 (CA 107: 74319k). 61. Ollivier, B., et al. 1985. "Separation and identification of phenolic acids by high-performance liquid chromatography and ultraviolet spectroscopy. Application to Parietaria officinalis L. and to Saint-John's-wort (Hypericum perforatum L.)." J. Pharm. Belg. 40: 173-7. 62. Guevich, A.I., et al. 1971. "Hyperforin, an antibiotic from Hypericum perforatum," Antibiotiki 16: 510-2. 63. Brondz, I., et al. 1983. "The absolute configuration of hyperforin, an antibiotic from Hypericum perforatum L., based on the crystal structure determination of its p-bromobenzoate ester," Acta Chem. Scand., Ser. A A37: 263-5 (in English). 64. Gurevich, A.I., et al. 1971. "Hyperforin, an antibiotic from Hypericum perforatum," Antibiotiki (Moscow) 16: 510-13 (CA 75:95625t). 65. Negrash, A.K. & P.Ya. Pochinok. 1972. "Comparative study of chemotherapeutic and pharmacological properties of antimicrobial preparations from common St. John's wort," Fitonotsidy, Mater. Soveshch. 6th, Meeting date 1969, 198-200 (CA 78:66908u). 66. Sticher, O. 1977. "Plant mono-, di- and sesquiterpenoids with pharmacological or therapeutical activity," in New Natural Products and Plant Drugs with Pharmacological, Biological or Therapeutical Activity, ed. by H. Wagner & P. Wolff, Springer-Verlag, NY. 67. Khosa, R.L. & N. Bhatia. 1982. "Antifungal effect of Hypericum perforatum,: J. Sci. Res. Plants Med. 3: 49-50. 68. Chialva, F., et al. 1981. "Study on the composition of the essential oil from Hypericum perforatum L. and Teucrium chamaedrys L.," Riv. Ital. EPPOS 63: 286-8 (CA 96:11497a). 69. Mathis, C. & G. Ourisson. 1964. Phytochemistry 3: 133. 70. Mathis, C. & G. Ourisson. 1964. "Etude chimio-taxonomique du genre Hypericum-IV," Phytochemistry 3: 377-8. 71. Brondz, I., et al. 1983. "n-Alkanes of Hypericum perforatum: a revision", Phytochemistry 22: 295-6. 72. Mathis, C. & G. Ourisson. 1964. "Etude Chimio-taxonomique du genre hypericum-III," Phytochemistry 3: 133-141. 73. Brondz, I. & T. Greibrokk. [d.m.]. "n-1-alkanols of Hypericum perforatum", Journal of Natural Products 46: 940-1. 74. Snider, S.R. 1984. "Octacosanol in Parkinsonism [letter]," Ann. Neurol. 16: 723. 75. Yamashita, M, et al. 1986. "Aqeuous compositions containing octacosanol," Japanese patent: JP 86263937, date: 861121. 76. Hohnen oil co., Ltd. 1985. "Encapsulated health food supplements," Japanese patent: JP 85149367 A2, date: 850806. 77. Mori, M. 1982. "n-hexacosanol and n-octacosanol: feeding stimulants on the larvae of the silkworm, Bombyx mori," J. of Insect Physiology 28: 969-73. 78. Tandan, R. & W.G. Bradley. 1985. "Amyotrophic lateral sclerosis: part I. Clinical features, pathology, and ethical issues in management," Ann. Neurol. (USA) 18/3: 271-80. 79. Gonsette, R.E. 1982. "Treatment of multiple sclerosis," Bull. Soc. Belge. Ophtalmol 199-200: 275-80. 80. Noris, F.H., et al. 1986. "Trial of octacosanol in amyotrophic lateral sclerosis," Neurology (USA) 36/9: 1263-64. 81. Costes, C. & T. Chantal. 1967. "Carotenoid pigments of the petals of the inflorescence of St.-John's- wort (Hypericum perforatum)," Ann. Physiol. Veg. 9: 157-77 (CA 68:66335y). 82. Kitanov, op cit. 83. Mathis C., & G. Ourisson. 1964. "Etude Chimio-taxonomique du genre Hypericum-V.", Phytochemistry 3: 379. 84. Prokosheva, L.I. & L.V. Shatunova. 1985. "Content of active substances in the aboveground parts of Hypericum perforatum," Rastit. Resur. 21: 461-3. 85. Gozin, A.A. & V.S. Yasnetsov. 1979. "Effect of mineral fertilizers on the content levels of biologically active substances in common St.-John's-wort," Depositied Doc., VINITI 1108-79, 8 pp. Avail. VINITI (CA 92:127708s). 86. Razinskaite, D. 1970. "Active substances of St.-Joh's-wort. 1. Dynamics of the level of tannins," Liet. TSR Mokslu Akad. Darb., Ser. C (1): 47-53 (CA 73:127742f). 87. Zhebeleva, T.I. 1973. "Effect of ecological conditions on the morphology and flavonoid accumulation of Hypericum perforatum," Rast. Resur. 9: 402-4 (CA 80:12660e). 88. Razinskaite, D. 1971. "Active substances of Hypericum perforatum St. John's wort). 2. Flavonoids and dynamics of their content", Liet. TSR Mokslu Akad. Darb., Ser. C (1): 89-100 (CA 75:72427r). 89. Tsitsina, S.I. "Results of studying some medicinal plants containing flavone compounds," Tr. Bot. Sadov, Akad. Nauk Kaz SSR 11: 111-14 (CA 73:32345q). 90. Morelli, I., et al. 1983. "Selected Medicinal Plants," FAO Plant Production and Protection Paper 53/1, Rome. 91. [author missing]. 1981. "Uterotonic action of extracts from a group of medicinal plants," Vet. Med. Nauki 18: 94-8. 92. [author missing]. 1988. Fitoterapia 59: 165. 93. Vander, A.J., et al. 1970. Human Physiology, McGraw-Hill Book Co., NY. 94. American Medical Association. 1983. AMA Drug Evaluations, AMA, Chicago. 95. Suzuki, O., et al. 1980. "Inhibition of type A and type B monoamine oxidase by isogentisin and its 3-0- glucoside," Planta Medica 39: 19-23. 96. Suzuki, et al. 1981. "Inhibition of type A and type B monoamine oxidases by naturally occurring xanthones," Planta Medica 42: 17-21. 97. Suzuki, O., et al. 1984. "Inhibition of monoamine oxidase by hypericin," Planta Medica 50: 272-4. 98. Okpanyi, Von S.N. & M.L. Weishcer. 1987. "Tierexperimentelle Untersuchungen zur psychotropen wirksamkeit eines Hypericum-extraktes," Arzneim.-Forsch. 37: 10-13. 99. Muldner, Von H. & M. Zoller. 1984. "Antidepressive wirkung eines auf den wirkstoffkomplex hypercin standardisierten hypericum-extraktes," Arzneim.-Forsch. 34: 918. 100. Negrash, A.K., op cit. 101. Aizenman, B.E. 1969. "Antibiotic preparations from Hypericum perforatum," Mikrobiol. Zh. (Kiev) 31: 128-33, (CA 70: 118006e). 102. Derbentseva, N.A. & A.S. Rabinovich. 1968. "Isolation, purification, and study of some physicochemical properties of novoimanin," in Novoimanin Ego Lech. Svoistva, 15-18, Edited by: Solov'eva, A.I., "Naukova Dumka": Kiev, USSR. 103. Gurevich, A.I., op cit. 104. Saljic, J. 1975. "Ointment for the treatment of burns," Ger. Offen. 2,406,452 (CL. A61K), 21 Aug 1975 (CA 83: 197797). 105. [author missing]. 1981. "Anti-inflammatory action of a group of plant extracts," Vet. Med. Nauki 18: 87-94. 106. Proserpio, G. 1976. "Natural sunscreens: vegetable derivatives as sunscreens and tanning agents," Cosmet. Toiletries 91: 34, 39-44, 46. 107. Morelli, I., op cit. 108. Meruelo, D., G. Lavie & D. Lavie. 1988. "Therapeutic agents with dramatic antiretroviral activity and little toxicity at effective doses: aromatic polycyclic diones hypericin and pseudohypericin," Proc. Natl. Acad. Sci. 85: 5230-5234. 109. Scheel, L.D. 1972. "Photosensitizing agents," in Toxicants Occuring Naturally in Food, National Academy of Sciences, Washington. 110. Weiss, R.F. 1988. Herbal Medicine, Beaconsfield Publishers Ltd, Beaconsfield, England. 111. Scheel, L.D., op cit. 112. Marsh, C.D. 1930. "Toxic effect of St. Johnswort (Hypericum perforatum) on cattle and sheep," USDA Technical bulletin No. 202. 113. Araya, O.S., op cit. 114. Garrett, B.J., et al. 1982. "Consumption of poisonous plants (Senecio jacobaea, Symphytum officinale, Pteridium aquilinum, Hypericum perforatum) by rats: chronic toxicity, mineral metabolism, and hepatic drug-metabolizing enzymes," Toxicology Letters 10: 183-88. 115. Pace, N. & G. MacKinney. 1941. "Hypericin, the photodynamic pigment from St. John's wort," Journal of the Am. CHem Soc. 63: 2570-74. 116. Clare, N.T. 1952. "Photosensitization in diseases of domestic animals," Review Sweries No. 3 of the Commonwealth Bureau of Animal Health, Commonwealth Agricultural Bureaux, Bucks, England. 117. James, L.F. & A.E. Johnson. 1976. "Some major plant toxicities of the western United States," J. of Range Manag. 29: 356-63. 118. Araya, O.S., op cit. 119. Zaichikova, S.G., et al. 1985. "Study of the healing properties and determination of the upper parameters of toxicity of Hypericum," Farmatsiya 1: 62. 120. Roth, L., et al. 1984. Giftpflanzen--Pflanzengifte, ecomed, Munich. 121. Weiss, R.F., op cit. 122. Merck 1907 Index. Merck & Co., Rahway, NJ. 123. Todd, R.G. 1967. Martindale's Extra Pharmacopoeia, The Pharmaceutical Press, London. 124. Georgiev, E., et al. 1985. Effect of solvent and moisture of St. John's wort on extraction of some biologically active substances. II. Extraction of hypericin with glycol," Nauchni Tr. - Vissh Inst. Khranit. Vkusova Prom-st., Plovdiv 32: 257-63 (CA 105:29872h). 125. Georgiev, E., et al. 1985. "Effect of solvent and moisture of St. John's Wort on extraction of some biologically active substances. I. Extraction of hypericin with glycerides and ethyl alcohol," Nauchni Tr. Vissh Inst. Khranit. Vkusova Promst., Plovdiv 32: 251-6 (CA 105:29871g). 126. Georgiev, E., et al. 1983. "Extraction of Hypericum perforatum L.," Nauchni Tr. - Vissh Inst. Khranit. Vkusova Prom-st., Plovdiv 30: 175-83 (CA 101: 197996n). 127. Adamski, R. & E. Styp-Rekowska. 1971. "Stability of hypericin in juice, dry extract, and tablets from Hypericum perforatum plants," Farm. Pol. 27: 237-41 (CA 75:91286k). 128. Araya, O.S. & E.J.H. Ford. 1981. "An investigation of the type of photosensitization caused by the ingestion of St. John's wort (Hypericum perforatum) by calves," J. COmp. Path. 91: 135-41. 129. Todd, R.G. (ed.). 1977. Martindale's Extra Pharmacopoeia, The Pharmaceutical Press, London. 130. Hoelzl, op cit. 131. Dorosiev, I. 1985. "Determination of flavonoids in Hypericum perforatum," Pharmazie 40: 585-6 (in English). 132. Ollivier, op cit. 133. Pachaly, P. 1984. "Thin layer chromatography in the pharmacy: Practical examples," Dtsch. Apoth. Ztg. 124: 2153-61. 134. Freytag, W.E. 1984. "Determination of hypericin and pseudohypericin in Hypericum perforatum L. with HPLC," Dtsch. Apoth. Ztg 124: 2383-6. 135. Vanhaelen, M. & R. Vanhaelen-Fastre. 1983. "Quantitative determination of biologically active constituents in medicinal plant crude extracts by thin-layer chromatography-densitometry. I. .....Hypericum perforatum...Silybum marianum..(and others)," J. Chromatogr. 281: 263-71 (in English). 136. Chialva, F. , et al. 1983. "Direct headspace gas chromatographic analysis with glass capillary columns in quality control of aromatic herbs," J. Chromatogr. 279: 333-40 (in English). 137. Holzl, J. & E. Ostrowski, op cit. 138. Steinbach, R.A. 1981. "Problems in the purification and standardization of plant drugs, for example, Hypericum," Z. Angew. Phytother. 2:221-4 (CA 98: 113563c) 139. Katalin, L., et al. 1982. "Ultrastructural Examination of leaf differentiation in St. John's wort", Herba Hung. 21: 21-37. 140. Azaryan, R.A. 1985. "Standardization of [quality indexes for the medicinal] herb Hypericum perforatum," Farmatsiya (Moscow) 34: 18-21 (CA 104: 56271x). 141. Schilling, W. 1969. "A Review.....," Praep. Pharm. 5: 125-34. © 1996
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