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Contents
B.H. Arjmandi
University of Illinois at Chicago, Chicago, IL 60612
A. Joffe, B.W. Hollis and D. Amin
Medical Univ. of South Carolina, Charleston, SC 29425ABSTRACT
The purpose of this study was to examine whether soy protein prevents bone loss induced by ovarian hormone deficiency. Thirty two 95 day-old Sprague-Dawley rats were divided into four equal groups: 1 = sham operated (sham) + solvent vehicle (sv); 2 = ovariectomized (ovx) + sv; 3 = ovx + soy protein + sv; 4 = ovx + estrogen (E2; 10 ug/kg body weight per day). Rats in groups 1, 2, and 4 were fed a Teklad diet that contained 0.4k calcium, 0.3k phosphorus, and 3.0 U vitamin D/g diet. Group 3 was fed a similar diet in which casein was replaced with soy protein (22.7 g/100 g diet). Animals in groups 1, 2, and 3 were pair fed to the ovx + E2 animals for 30 days from the date of surgery. Rats had free access to deionized water. The animals were sacrificed 30 days after surgery. Ovariectomy decreased the densities of the right and left femurs (p < 0.001 vs sham) and the fourth lumbar vertebra (p < 0.05 vs sham). These decreases in bone density were completely prevented in animals receiving E2. Compared to the control diet, the soy protein diet was also effective in preventing bone loss in the left femur and the fourth lumbar vertebra. Ovariectomy significantly increased serum levels of 1,25(OH)2 vitamin D (p < 0.01 vs sham), whereas E2 administration and soy protein prevented the rise in 1,25(OH)2 vitamin D. Our findings suggest that dietary soy protein is effective in preventing bone loss due to ovarian hormone deficiency. Further studies are needed to clarify whether this bone protective effect is due to the protein itself or to the presence of phytoestrogens, such as genistein and daidzein in soy protein.
Presented at the American Society for Bone and Mineral Research, 1994.
Raga M. Bakhit Division of Foods and Nutrition
Barbara P. Klein Division of Foods and Nutrition / Division of Nutritional Sciences
Diane Essex-Sorlie College of Medicine, University of Illinois at Urbana-Champaign,
Urbana, IL 61801
Joan O. Ham Division of Nutrional Sciences
John W. Erdman, Jr. Division of Nutritional Sciences / College of Medicine, Univeristy
Of Illinois, Urbana, IL 61801ABSTRACT
Twenty-one mildly hypercholesterolemic men consumed a diet that was low in fat (<30% of energy) and cholesterol (300 mg/d) and were given muffins containing 25 g protein + 20 g dietary fiber daily from either isolated soybean protein + soybean cotyledon fiber, isolated soybean protein + cellulose, casein + soybean cotyledon fiber or casein + cellulose. All subjects progressed through the low fat, low cholesterol baseline period, lasting 2 wk, and then through all four dietary treatments, lasting 4 wk each, according to a Latin square design. Plasma concentrations of total, LDL, HDL and VLDL cholesterol, total and VLDL triacylglycerols, and apolipoprotein A-I and B were measured at the end of each period. When data from all subjects were analyzed, dietary treatments did not influence lipemia; however, in subjects with initial total cholesterol concentrations >5.7 mmol/L, both isolated soybean protein treatments resulted in significantly lower total cholesterol compared with the two casein treatments (P < 0.05). In addition, a negative linear relationship was observed when a subject's total or LDL cholesterol change after each of the soybean treatments was regressed against the subject's baseline cholesterol concentration (P < 0.05). Apolipoprotein A-I varied dependent on baseline cholesterol with no apparent pattern, whereas apolipoprotein B levels were not affected. Results indicate that consumption of 25 g soybean protein/d is associated with lower total cholesterol concentrations in individuals with initial cholesterol concentrations >5.7 mmol/L.
INDEXING KEY WORDS: soybeans, soybean protein, soy fiber, cholesterol, humans
E.J. Hawrylewicz, W.H. Blair, J.J. Zapata, H.H. Huang
Mercy Hospital and Medical Center, Chicago, ILABSTRACT
We reported that a soybean protein (SBP) diet, low in essential methionine, significantly delayed mammary tumor (MT) progression in the adult rat without any effect on body weight. Present study determined the effect of SBP diet on recurrence of MT after excision of the primary tumor. After weaning, S/D female rats (N=75) were fed casein, 20% (C) diet. NMU (N-nitrosomethylurea, 55mg/kg B.W.) was administered at 7 wks of age. Primary MT was excised and rats randomly placed into diet groups: (C), SBP-19% or SBP-38%. Four weeks after excision of the primary MT, 83.3% of the animals in group C had MT recurrence. Only 23% occurred in SBP-19% and 43.5% in SBP-33% groups. Total number of recurrent MT in each diet group: C, SBP-19% and SBP 33% was 128, 53 and 98 respectively. Total weight of recurrent MT in each diet group: C, SBP-19%, SBP-33% was 221.9g, 110.9g and 221.3g respectively. Coded tumor sections were evaluated histopathologically. Eighty-six percent of the primary MT were classified as adenocarcinoma with the most aggressive characteristics (Grades 3 and 2+). Recurrent tumors were classified as follows: C, Grades 3 and 2+, 45.56k (N=36), and fibroadenoma, 7.59W (N=6). In contrast, group SBP=19%, Grades 3 and 2+, 26.47% (N=9) and fibroadenoma 20.58% (N=7). Group SBP-33%, Grades 3 and 2+, 29.16% (N=21) and fibroadenoma 25% (N=18). The results indicate that methionine deficient soybean protein diet significantly inhibited mammary tumor recurrence and histopathologic development without altering food consumption or body weight of the animal.
Presented at the First International Symposium on the role of Soy in Preventing and Treating Chronic Disease, February 20-23, 1994, Mesa, Arizona.
G. Luo
Present address: UT M. D. Anderson Cancer Center, Box 45, 1515 Holcombe Blvd.,
Houston, TX 77030
A. Hepburn
Profile Diagnostic Sciences, Inc., 510 E. 73rd St., New York, NY 10021
J. Widholm
Department of Agronomy, University of Illinois, PABL, 1102 W Gregory,
Urbana, IL 61801, USA
ABSTRACT
Cotyledons from germinating seeds of the soybean cultivar Peking were inoculated with virulent Agrobacterium tumefaciens strain A281:pZA-7 which carries a wild type Ti plasmid pTiBo542 and a disarmed Ti plasmid (a binary vector) pZA-7 which contains the S-glucuronidase (uidA) and neomycin phosphotransferase (nptII) genes. Tumors were produced on all inoculated explants and 82% of these tumor lines were co-transformed by the nptII gene from the binary vector pZA-7 as shown by PCR analysis (18 of 22 lines tested). Eleven of these 18 lines were also resistant to kanamycin. Eleven lines expressed S-glucuronidase activity (GUS), six of which were also kanamycin resistant. Since there is a high rate of coexpression of genes carried by the binary vector, this system provides a simple and rapid method for the expression of genes of interest in transformed soybean tissue which has been used successfully to test constructs designed for soybean transformation.
Susan M. Potter, Raga M. Bakhit, Diane L. Essex-Sorlie, Karl E. Weingartner, Karen M. Chapman,
Ralph A. Nelson, M. Prabhudesai, William D. Savage, Alvin I. Nelson, Lewis W. Winter and
John W. Erdman, Jr.
Division of Foods and Nutrition, Division of Nutritional Sciences, Department of Food
Science, International Soybean Program, and College of Medicine, University of Illinois at
Urbana-Champaign, and the Veterans' Affairs Medical Center, Danville, IL
ABSTRACT The effects of soy-protein consumption with and without soy fiber on plasma lipids in 26 mildly hypercholesterolemic men were studied. Four 4-wk dietary treatments included 50 g protein and 20 g dietary fiber from soy flour (SF), isolated soy protein/soy cotyledon fiber (ISP/SCF), ISP/cellulose (ISP/C), or nonfat dry milk/C (NFDM/C) in conjunction with a low-fat, low- cholesterol, Plasma total cholesterol (TC) concentrations were lowest for both ISP dietary treatments compared with baseline (P c 0.05) and NFDM/C (P < 0.01). SF also led to lower TC compared with NFDM/C (P < 0.05). LDL-cholesterol values were lowest for both ISP treatments compared with NFDM/C (P < 0.01), but lower compared with baseline only with ISP/SCF (P < 0.05). Apolopoprotein B was lowest when ISP/C was fed, compared with baseline, SF, and NFDM (P < 0.05). HDL-cholesterol and total triglycerides (TG) were not affected. Results indicate that 50 g ISP is effective in lowering TC, LDL-C, and apolipoprotein B while maintaining HDL concentrations in mildly hypercholesterolemic men. (Supported by the Illinois Soybean Program Operating Board, Protein Technologies International, St. Louis, and the United Soybean Board.)
KEY WORDS: Soy, soy protein, fiber, cholesterol, triglycerides