2010 Annual Report
We determined the metabolic mechanism underlying the prevention of obesity related chronic diseases by soluble dietary fiber in an animal model. Fat fed hamsters become insulin resistant, develop high blood cholesterol and triglyceride, and all of the similar characteristics of human metabolic diseases. We used a semisynthetic cellulose fiber that we have shown is not absorbed by the body or broken down by colonic bacteria but still possess strong antidiabetic properties. Examination of the genes expressed by healthy fat fed animals compared to unhealthy fat fed animals show that the cholesterol and bile acid pools were depleted in the healthy fat fed animals resulting in lower blood cholesterol levels. In the liver fat, was being oxidized instead of synthesized so that less fat was accumulating in the liver and other organs. The prevention of metabolic diseases by these soluble dietary fibers has resulted in six patent applications. This research was published in one of the most highly regarded nutrition journals and highlighted in the society’s newsletter.
Bioactive peptides from rice bran, millet, and other cereal or seed proteins are being developed in collaboration with Jiangnan University, Wuxi, China. Rice bran and millet proteins were extracted and hydrolyzed by various food grade enzymes. The original intact protein and its hydrolysates were evaluated for cholesterol reducing properties by an in vitro method. Bile acid micelles containing cholesterol that mimic intestinal cholesterol absorption were used to evaluate the ability of the protein hydrolysates to block absorption. A few model peptides were purchased to evaluate their ability to block cholesterol absorption in animal models as well as act as positive controls for the in vitro and in vivo studies. Ultimately, these methods will be used to identify peptides that have antidiabetic properties that will be tested in animal models.
Prasopsunwattana, N., Omary, M.B., Arndt, E.A., Cooke, P.H., Flores, R.A., Yokoyama, W.H., Toma, A., Chongcham, S., Lee, S.P. 2009. Particle Size Effects on the Quality of Flour Tortillas Enriched with Whole Grain Waxy Barley. Cereal Chemistry. 86(4):438-451
Hung, S., Bartley, G.E., Young, S.A., Albers, D., Dielman, D., Anderson, W.H., Yokoyama, W.H. 2009. Dietary Fiber Improves Lipid Homeostatis and Modulates Adipocytokines in Hamsters. Journal of Diabetes. 1:1-13. Young, S.A., Julka, S., Bartley, G.E., Gilbert, J.R., Wendelburg, B., Hung, S., Anderson, W., Yokoyama, W.H. 2009. Quantification of the Sulfated Cholecystokinin CCK8 in Hamster Plasma Using Immunoprecipitation-Liquid Chromatography-Mass Spectrometry/Mass Spectrometry. Analytical Chemistry. 81:9120-8.
Villanueva, M., Yokoyama, W.H., Hong, Y., Bartley, G.E., Ruperez, P. 2010. EFFECT OF HIGH-FAT DIETS SUPPLEMENTED WITH OKARA SOYBEAN BY-PRODUCT ON LIPID PROFILES OF PLASMA, LIVER AND FAECES IN SYRIAN HAMSTERS. Journal of Food Chemistry. Doi:10.1016/j.foodchem.2010.05.106.
Kalgaonkar, S., Gross, H., Yokoyama, W.H., Keen, C. 2010. Effects of flavonol-rich diet on select cardiovascular parameters in a Gold Syrian Hamster model. Journal of Medicinal Food. 13(1): 108-115. doi:10.1089/jmf.2008.0295.
Langhorst, M., Hastings, M.J., Yokoyama, W.H., Hung, S., Young, S.A., Cellar, N., Kuppannan, K. 2010. Determination of F2-isoprostanes, biomarkers of oxidative stress in hamster urine samples by on-line solid phase extract. Journal of Agricultural and Food Chemistry. 58 (11), pp 6614–6620. DOI: 10.1021/jf101146q.