Plant Profiler

Barley (Hordeum vulgare)


Synonyms / Common Names / Related Terms
Barley flour, barley malt, barley oil, beta-glucan, brewers spent grain, dietary fiber, germinated barley, high protein barley flour (HPBF), Gramineae (family), high fiber barley, hordenine, hordeum, Hordeum distychum, Hordeum dislichon, Hordeum murinum, Hordeum vulgare var Himalaya 292, Hordeum vulgare ssp spontaneum, lunasin, mai ya, pearl barley, Poaceae (family), pot barley, tocols, tocopherols, tocotrienols, scotch barley, vitamin E, wild barley grass, wild barley.





Mechanism of Action
Pharmacology:
  • Constituents: Barley contains varying amounts of total tocopherols and tocotrienols (49.9-67.6mg/kg) and vitamin E content (vitamin E equivalent; 15.7-20.1mg/kg).10
  • Anti-carcinogenic effects: Lunasin, a novel, cancer-preventive peptide found in barley, internalizes into mammalian cells within minutes of exogenous application and localizes in the nucleus after 18 hours. It inhibits acetylation of core histones in mammalian cells. Lunasin does not affect the growth rate of normal and established cancer cells, but is selective for cells being transformed or newly transformed by binding to deacetylated core histones exposed by the transformation event, disrupting the dynamics of histone acetylation-deacetylation and leading to cell death.3
  • Antihypertensive effects: Behall et al. conducted a controlled crossover study to assess the effects of predominantly insoluble fiber (whole wheat and brown rice) and soluble fiber (barley) in a whole-grain diet on blood pressure.8 After consuming a controlled Step I diet for two weeks, a total of 25 mildly hypercholesterolemic subjects (seven men, nine premenopausal women, and nine postmenopausal women) ingested a Step I diet with about 20% of energy provided by whole wheat/brown rice, barley, or half wheat-rice/half barley, for five weeks each. The primary outcomes were blood pressure, which was measured weekly, and weight, which was measured daily before breakfast. The authors report that systolic pressure decreased after the wheat/rice and half wheat-rice/half barley diets. Diastolic and mean arterial pressures were reduced by all whole-grain diets. There were no differences in urinary mineral or urea nitrogen excretion.
  • Cholesterol effects: Two barley products, barley oil and brewer's spent grains (BSG), neither of which contains soluble fiber, have been investigated for their potential positive impact on lipid metabolism. Brewer's spent grains (BSG) is a by-product of the brewing industry and typically contains 98% insoluble dietary fiber and is high in protein (20-30%) and lipid (6-10%) and contains three times more tocotrienols than the whole grain. The combined animal and human studies on barley oil and brewer's spent grains suggest that some components, possibly the tocotrienols which are an antioxidant, have the ability to effect lipid controlling enzymes and lower cholesterol.1 Plasma lipid-lowering effects of barley have been attributed to rich amounts of beta-glucan, a water-soluble fiber.2,11,12 The beta-glucan component of barley is believed to slow gastric emptying time, prolong the feeling of fullness, and stabilize blood sugars. Other contributory factors may be d-alpha-tocotrienol.13 In chicks, high protein barley flour (HPBF)-based diets increase body weight (18%), suppress HMG-CoA reductase (-36%), impair fatty acid synthetase (-40%), and decrease serum triglyceride (-9%) and cholesterol levels (-23%).9
  • Gastrointestinal effects: Germinated Barley Foodstuff (GBF) is derived from the aleurone and scutellum fractions of germinated barley. GBF appears to induce proliferation of intestinal epithelial cells and facilitate defecation through bacterial production of short chain fatty acids, especially butyrate. GBF is believed to facilitate epithelial repair and suppress epithelial NFkB-DNA binding activity through butyrate (by the microflora bifidobacterium and eubacterium). GBF has been associated with increased growth of these microflora in the intestinal tract.14,6
  • Glycemic/insulinemic effects: Barley contains more fermentable carbohydrate than other cereals such as rice. Fermentation of undigested carbohydrate produces short chain fatty acids, some which may reduce hepatic glucose production and affect postprandial glycemia.7 Because of viscous properties of beta-glucans, boiled flours appear to produce higher glucose and insulin responses when compared with milled kernels.15 According to a controlled study in 18 lean, healthy men ingesting barley beta-glucan given with high- carbohydrate food and high-carbohydrate drinks, beta-glucan significantly decreased glycemic and insulinemic responses on the food (p<0.05) but not on the drink (p>0.05) treatments, compared to controls.4 In another study comparing crackers and cookies made of whole wheat or barley, the barley crackers and cookies had glycemic indices of 49 and 34, respectively, whereas whole wheat crackers and cookies had 78 and 81, respectively.5
  • Metabolic effects: Barley products composed of boiled intact (rice extender) and milled kernels (porridge) with different amylose-amylopectin ratios (7-44% amylose) have been reported to lower metabolic responses and raise satiety scores compared to white/wheat bread.15
  • Sympathomimetic effects: Hordenine, an aminophenol in the root of germinating barley is a sympathomimetic. Human effects in this area have not been studied.

Pharmacodynamics/Kinetics:
  • Barley contains greater amounts of soluble and non-soluble starches compared to other cereals, and approximately 17% of the carbohydrate in barley is not absorbed. This leads to fermentation in the colon by microflora, measurable by the H2 breath test.7
  • In a randomized, single-blinded crossover study examining the effect of barley flour (Hordeum vulgare var Himalaya 292) and white wheat flour on metabolic parameters in 14 healthy women, the mean area under the glycemic response curve (AUC) was 3.67 ± 1.91mM/L/hour for barley-containing meals and 4.68 ± 1.67mM/L/hour for wheat-containing meals, which is 22% more than the barley meal (p=0.05).16 The AUC of insulin in response to barley-containing meals was 52.8 ± 24.7mU/L/hour, which was 32% less than wheat-containing meals (78.1 ± 35.3mU/L/hour; p<0.02).

References
  1. Lupton, J. R., Robinson, M. C., and Morin, J. L. Cholesterol-lowering effect of barley bran flour and oil. J Am Diet Assoc 1994;94(1):65-70. 8270757
  2. McIntosh, G. H., Whyte, J., McArthur, R., and Nestel, P. J. Barley and wheat foods: influence on plasma cholesterol concentrations in hypercholesterolemic men. Am J Clin Nutr 1991;53(5):1205-1209. 1850576
  3. de Lumen, B. O. Lunasin: a cancer-preventive soy peptide. Nutr Rev 2005;63(1):16-21. 15730231
  4. Poppitt, S. D., van Drunen, J. D., McGill, A. T., Mulvey, T. B., and Leahy, F. E. Supplementation of a high-carbohydrate breakfast with barley beta-glucan improves postprandial glycaemic response for meals but not beverages. Asia Pac J Clin Nutr 2007;16(1):16-24. 17215176
  5. Casiraghi, M. C., Garsetti, M., Testolin, G., and Brighenti, F. Post-prandial responses to cereal products enriched with barley beta-glucan. J Am Coll Nutr 2006;25(4):313-320. 16943453
  6. Kanauchi, O., Iwanaga, T., and Mitsuyama, K. Germinated barley foodstuff feeding. A novel neutraceutical therapeutic strategy for ulcerative colitis. Digestion 2001;63 Suppl 1:60-67. 11173912
  7. Thorburn, A., Muir, J., and Proietto, J. Carbohydrate fermentation decreases hepatic glucose output in healthy subjects. Metabolism 1993;42(6):780-785. 8510524
  8. Behall, K. M., Scholfield, D. J., and Hallfrisch, J. Whole-grain diets reduce blood pressure in mildly hypercholesterolemic men and women. J Am Diet Assoc 2006;106(9):1445-1449. 16963350
  9. Burger, W. C., Qureshi, A. A., Din, Z. Z., Abuirmeileh, N., and Elson, C. E. Suppression of cholesterol biosynthesis by constituents of barley kernel. Atherosclerosis 1984;51(1):75-87. 6721904
  10. Ehrenbergerova, J., Belcrediova, N., Pryma, J., Vaculova, K., and Newman, C. W. Effect of cultivar, year grown, and cropping system on the content of tocopherols and tocotrienols in grains of hulled and hulless barley. Plant Foods Hum Nutr 2006;61(3):145-150. 16900405
  11. Delaney, B., Nicolosi, R. J., Wilson, T. A., Carlson, T., Frazer, S., Zheng, G. H., Hess, R., Ostergren, K., Haworth, J., and Knutson, N. Beta-glucan fractions from barley and oats are similarly antiatherogenic in hypercholesterolemic Syrian golden hamsters. J Nutr 2003;133(2):468-475. 12566485
  12. Poppitt, S. D. Soluble fibre oat and barley beta-glucan enriched products: can we predict cholesterol-lowering effects? Br J Nutr 2007;97(6):1049-1050. 17381959
  13. Qureshi, A. A., Burger, W. C., Peterson, D. M., and Elson, C. E. The structure of an inhibitor of cholesterol biosynthesis isolated from barley. J Biol Chem 8-15-1986;261(23):10544-10550. 3733719
  14. Kanauchi, O., Fujiyama, Y., Mitsuyama, K., Araki, Y., Ishii, T., Nakamura, T., Hitomi, Y., Agata, K., Saiki, T., Andoh, A., Toyonaga, A., and Bamba, T. Increased growth of Bifidobacterium and Eubacterium by germinated barley foodstuff, accompanied by enhanced butyrate production in healthy volunteers. Int J Mol Med 1999;3(2):175-179. 9917526
  15. Granfeldt, Y., Liljeberg, H., Drews, A., Newman, R., and Bjorck, I. Glucose and insulin responses to barley products: influence of food structure and amylose-amylopectin ratio. Am J Clin Nutr 1994;59(5):1075-1082. 8172094
  16. Keogh, J. B., Lau, C. W., Noakes, M., Bowen, J., and Clifton, P. M. Effects of meals with high soluble fibre, high amylose barley variant on glucose, insulin, satiety and thermic effect of food in healthy lean women. Eur J Clin Nutr 2007;61(5):597-604. 17164830




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