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U.S. Department of Health and Human Services

FDA Poisonous Plant Database

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AUTHOR(S): Hintz, H. F.
TITLE: Hordenine.
YEAR: 1988 CITATION: Equine Pract, 10(2), 17 [English]
FDA #: F22087
ABSTRACT: Hordenine (p hydroxyphenylethyl dimethylamine) is an alkaloid that has actions similar to that of epinephrine. It stimulates the heart, constricts vessels and relaxes constricted bronchioles.1 Hordenine is of concern to veterinarians and horse owners because some organizations, such as the racing commissions in New Jersey and West Virginia, disqualify racehorses if hordenine is found in the urine. However, many organizations do not act against hordenine. How might a horse be exposed to hordenine? Hordenine can be found in many plants such as certain algae, fungi, marijuana, mistletoe, some members of the amaryllis family, some members of the lily family, Christmas berry tree, and heavenly bamboo.2 It can also be found in the leaf and fruit of the mandarin orange but not in the grapefruit or orange.3 Many species of cacti contain hordenine. The antibiotic activity of an extract of the hallucinogenic peyote cactus is thought to be due to hordenine which was previously called peyocactin.4 In humans, plants containing hordenine have been used as a remedy for diarrhea. Plants such as Desmodium triflorum, a legume which is common throughout India, that have been used as a treatment for dysentery and as a diuretic have been effective because of the hordenine content.2 Hordenine is of great concern to the brewing industry. It is formed during the sprouting of barley and, therefore, is in malt.3 The hordenine can be converted to the nitrosamine, nitrosodimethyiamine (NDMA). The nitrosamine content of beer is of concern because of the possible role of nitrosamine as a cause of cancer. Sprouting millet,7 sorghum,4 and wheat4 can also contain hordenine. But horses are perhaps most likely to encounter hordenine in reed canary grass or barley. Coulman et al.8 reported that the hordenine content of reed canary grass was highest in the leaf sheaths, being more than twice as high as that in blades and four times as high as in stems. The total forage content was 1,220 ?g/g of dry matter. Hordenine and other alkaloids have been associated with decreased palatability and poor weight gains in ruminants9 and ponies10 grazing on reed canary grass. The poor weight gains are probably the result of the reduced intake. Coulman et al.11 concluded that the hordenine did not interfere with the activity of the rumen microflora. As mentioned earlier, sprouted barley contains significant amounts of hordenine. The name for the compound was derived from the scientific name for barley, Hordeum vulgare. Thus, horses should not be fed germinating barley if hordenine in urine is of concern. Horse feeds containing barley should be protected from moisture to prevent sprouting. Wooden storage bins might be better than metal ones because of the condensation of water on the inside wall of the metal bin. The use of barley grain in hydroponics fed to horses could greatly increase the hordenine intake. I could find no evidence that the amount of hordenine found in reed canary grass or sprouted barley had any significant physiological effect on the horse. Dr. Richard Sams, Director of the Ohio State Racing Commission Testing Laboratory, gave hordenine orally to horses and found no change in heart rate and no change in the behavior of the horses; that is, the horses were neither more excited nor more depressed after the oral dose.12 References: 1. Reilly PJ: The Detection and Identification of Hordenine in the Horse. Fourth Intern Conf Control of the Use of Drugs in Racehorses. Melbourne, p. 165 166, 1981. 2.Smith TA: Phenethylamine and Related Compounds in Plants. Phytochemistry 16:9 18, 1977. 3. Weaton TA, Stewart I: The Distribution of Tyramine, N methyltyramine, Hordenine, Octopamine and Synephrine in Higher Plants. Lloydia 33:244 250, 1970. 4. Rao GS: Identity of Peyocactin, an Antibiotic from Peyote (Lophophora williamsii), and Hordenine. J Pharm Pharmacology 22:544 545, 1970. 5. Ghosal S, Srivastan RS, et al: Desmodium Alkaloids. IV Chemical and Pharmacological Evaluation of D. Triflouin. Planta Med 23:321 328, 1972. 8.Wainwright T: Nitrosamines in Malt and Beer. J Inst Breweries 92:73 80, 1986. 7. Brady LR. Tyler VE: Biosynthesis of Hordenine in Tissue Homogenates of Panicum miliaceum. Plant Physiol 33:334-340, 1958. 8. Coulman BE, Woods DL, et al: Distribution Within the Plant,Variation with Maturity and Heritability of Gramine and Hordenine in Reed Canary Grass. Can J Plant Sci 57:771 777. 1977. 9. S.Marten GC, Jordan RM, et al. Biological Significance of Reed Canarygrass Alkaloids and Associated Palatability Variation to Grazing Sheep and Cattle. Agron J 68:909 914. 1976. 10. Jordan RM, Marten GC: Effect of Three Pasture Grasses on Yearling Pony Weight Gains and Pasture Carrying Capacity. J Anim Sci 40:86 89.1975. 11.Coulman BE, Woods DL, et al: Effects of Selected Reed Canary Grass Alkaloids on In Vitro Digestibility. Can J Plant Sci 57: 779-785. 1977. 12. Personal communication
GRIN #: 13680 Exit Disclaimer
LATIN NAMEDesmodium triflorum
STANDARD PLANT NAMEDesmodium triflorum (L.) DC.
GRIN #: 19333 Exit Disclaimer
LATIN NAMEHordeum vulgare
STANDARD PLANT NAMEHordeum vulgare L. subsp. vulgare
GRIN #: 27512 Exit Disclaimer
COMMON NAME: reed camary grass
STANDARD PLANT NAMEPhalaris arundinacea L.