• Journal of Nutrition and Health
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• v.36 no.5
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• pp.452-458
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• 2003

Soybean is a rich source of isoflavones such as genistein and daidzein. Soy isoflavones have both weak estrogenic and anti-estrogenic effects and are structurally similar to tamoxifen, an agent that has an effect similar to that of estrogen in terms of reducing postmenopausal bone loss. The purpose of this study was to determine the effects of differences in protein source (casein vs soy) and isoflavone levels (reduced vs higher levels) on selected bone markers and hormones in growing male rats. Thirty weanling Sprague-Dawley young rats were divided into 3 groups: The control group was fed a casein-based diet, the soy concentrate group was fed soy protein with totally reduced isoflavones content (isoflavones 0.07 mg/g protein), and the soy isolate group was fed soy protein with a higher than normal isoflavones content (isoflavones 3.4 mg/g protein). The degree of bone formation was estimated by measuring serum osteocalcin and alkaline phosphoatase (ALP). By determining collagen cross-linkage by immunoassay and correcting with creatinine values, the bone resorption rate was compared. Serum osteocalcin, growth hormone, estrogen and calcitonin were analyzed using radio immunoassay kits. The bone formation marker and ALP activity were differentiated by protein source, showing higher values than casein in feeding either soy isolate or soy concentrate. In this study using growing rats, the differences in isoflavone contents were not a significant factor in either bone formation or bone reaborption markers. Moreover, the soy isolate group had significantly higher levels of growth hormone than the casein group. The findings of this study suggest that growth hormone is partially responsible for its bone-formation effects in young growing rats. Soy protein and the isoflavones in soy protein are beneficial for bone-formation in growing male rats. Therefore, exposure to soy protein and isoflavones early in life may have long-term health benefits in preventing bone diseases such as osteoporosis. Further study to evaluate the mechanism of action of isoflavones on bones is warranted. (Korean J Nutrition 36(5): 452∼458, 2003)

• Journal of Nutrition and Health
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• v.28 no.9
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• pp.817-824
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• 1995

This study was performed to evaluate the effect of dietary protein level on Ca efficiency in bone mineral density in growing male rats. Twenty male rate were divided into two groups. The rats in one group were fed on casein 20% diet as control group and the others were fed on casein 40% diet as protein group. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. The total body, spine and femur bone mineral density and bone mineral content were measured using dual energy-x ray absorptiometry. Urinary calcium, phosphate, pyridinoline and creatinine, serum calcium, phosphate, total protein, albumin, alkaline phosphatase(ALP) and osteocalcin were measured. Urinary Ca excretion, pyridinoline and crosslinks value and serum ALP content seem to be increased in high protein group. It appears that the growing rats in high protein group had a higher bone resprption and bone formation than those in control group. Animal fad a high protein diet had a siginficantly higher Ca efficiency in BMD, BMC of total body, spine and femur. The results of this show that increasing of dietary protein level (40%) is beneficial of improvement of Ca efficiency during growing period.

• Journal of Nutrition and Health
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• v.38 no.5
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• pp.373-379
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• 2005

This study was performed to determine the effect of isoflavone on bone mineral density and bone mineral content in growing male rats. Twenty male, Sprague-Dawley rats were assigned to groups, that underwent 9 weeks of experi-ental treatment. Animals were assigned to one of two diet groups (casein group or casein supplemented with isoflavones). During 9 week of the study, food consumption was determined every other day through the measurement of total food given subtracting the food uneaten from original amount given. Rats in two experimental groups had similar initial body weights. At the end of experiment, however, the casein group had significantly greater body weights compared to casein supplemented with isoflavones group. It was also observed that the casein group had greater food intake comared to casein supplemented with isoflavones group. The difference in the final body weights of the groups was therefore due to difference in amount of food ingested, but could be due to the effect of isoflavones. Total BMD, spine BMD, and spine BMC per weight and femoral BMD per weight were significantly greater in casein supplemented with isolaones group than casein group. ALP and osteocalcin were significantly greater in the casein-fed group. Crosslink value was significantly lower in the casein supplemented with isoflavones group, All other variables were statistically similar between two groups. Overall, it can be concluded that casein supplemented with isoflavones beneficial for acquisition of bone mineral density and content on growing male rats.

• Journal of Community Nutrition
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• v.6 no.1
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• pp.48-54
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• 2004

The purpose of this study was to examine the effects of dietary protein and exercise on bone mineral density and bone mineral content of growing male rats. Forty male, Sprague-Dawley rats(age 21 days) were assigned to four groups that underwent 9 weeks of experimental treatment. Animals were assigned to one of two exercise treatments (treadmill running or sedentary). The exercise and nonexercise group were fed a diet containing casein or soy with rich isoflavones (3.4mg/g protein). The exercise group ran on a rodent treadmill(speed of 15m/min for 30min) three days per week during the 9-week study period. All rats were fed an experimental diet and deionized water ad libitum for 9 weeks. Total bone mineral density (BMD), total bone mineral content (BMC), total body calcium, spine BMD and BMC, and femur BMD and BMC were determined by using dual energy x-ray absorptiometry (FIXI-mus, GE Lunar Radiation Cooperation, Madison, WI, USA). The soy diet group appears to have a significantly higher total BMD/weight and total BMC/ weight, spine BMD/weight, spine BMC/weight, femur BMD/weight and femur BMC/weight compared to the casein group in nonexercise and exercise. The exercise group had significantly greater total BMD/weight and BMC/ weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight compared to the nonexercise group when the protein source was casein. The exercise combined soy group had significantly greater total BMD/weight and BMC/weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight, compared to the exercise combined casein group. The results indicate that exercise had a positive influence on bone mineral density and bone mineral content and soy significantly affect on bone mineral density and bone mineral content for the 9 weeks experimental period. It can be concluded that exercise combined with a soy diet is most beneficial for acquisition of spine bone mineral density in young growing male rats. This convincing evidence suggests that a change in life style such as increasing exercise and consumption of soy protein is a practical strategy for significantly reducing the incidence of osteoporosis.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.2
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• pp.278-286
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• 2015

The overall purpose of this study was to investigate the effects of Chunggukjang and Greentea-Chunggukjang on the lipid profile, lipid peroxidation and antioxidative enzyme activities of liver tissue in growing male rats fed cholesterol. Twenty seven rats were divided into three treatment groups (Control, Chunggukjang and Greentea-Chunggukjang) and were given experimental diets with 1% cholesterol for 9 weeks. All rats in this study were fed a casein-based diet. Chunggukjang groups were fed diet containing 33.1% Chunggukjang powder. The Chunggukjang and Greentea-Chunggukjang groups showed significantly lower weight gain, food efficiency ratio than the control group regardless of Chunggukjang type. Serum total cholesterol was significantly lower in the Chunggukjang group than in the control group, whereas serum triglyceride and atherogenic index were significantly lower in the Greentea-Chunggukjang group than in the control group. Hepatic triglyceride contents was not significantly different among the diets. However, hepatic cholesterol content was significantly lower in the Greentea-Chunggukjang group than in the control group. Lipid peroxidation of malondialdehyde (MDA) contents was significantly lower in the Chunggukjang and Greentea-Chunggukjang groups than in the control group. Activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in liver tissue of the Chunggukjang and Greentea-Chunggukjang groups were not significantly different. It can be concluded that Chunggukjang and Greentea-Chunggukjang influence lipid profile and hepatic malondialdehyde contents in growing male rats fed cholesterol.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.466-472
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• 2008

The purpose of this study was to investigate the effect of dietary caffeine supplementation(0.033%/diet) on the plasma and liver lipid concentrations in rats. Twenty male Sprague-Dawley rats(body weight $200{\pm}10\;g$) were divided into two groups: the control group and the caffeine-supplemented group(0.033% caffeine-supplemented diet). All rats were fed an experimental diet, and deionized water was avaliable ad libitum for 6 weeks. Plasma lipid concentrations were measured with a commercial kit based on an enzymatic method, and liver lipid concentrations were measured using the Folch method. There were no significant differences in body weight gain, food intake or food efficiency ratio between the control and caffeine-supplemented group. The total cholesterol and LDL-cholesterol levels as well as the AI(athrogenic index) were significantly higher in rats fed the caffeine diet(0.033%) than in those fed the control diet. There were no significant differences in the liver total cholesterol and triglyceride levels between the control and caffeine-supplemented groups. Therefore, it seems possible that caffeine(0.033 g/100 g diet) may increase the plasma lipid concentration level in growing rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.1
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• pp.57-68
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• 1982

In order to investigate the effect of dietary protein and energy on growing female and male rats, Sprague-Dawley 90 female rats and 54 male rats of 3 weeks old weighing approximately 70-80g and 65-75g, respectively, were subjected to feeding trials for 8 weeks and then subsquently to metabolic trials for 2 weeks. Three dietary energy levels (3200, 3600, 4000 kcal ME/kg) were employed and each energy level contained three protein levels (15, 25, 35% of 3600 kcal ME/kg) and three fat levels (10, 20, 40% of 3600 kcal ME/kg) by addition of an appropriate amount of carbohydrate and the following results were obtained. The body weight gain of female rats was highest for LPHE ration but that of male rats was highest for LPME ration. The weight gains both of female and male rats were not affected by the level of protein. Food efficiencies both of female and male rats was affected by the level of protein, whereas that of male rats was not. Protein efficiencies of female and male rats were highest at low protein level and tended to decrease as the level of protein increased, but that of female rats was highest at high energy level, while that of male rats was highest at medium energy level. The analysis of the body composition after feeding trials for 8 weeks has shown that the contents of body water and protein were not affected by protein level both in female and male rats. The content of body fat increased remarkably as the protein and energy levels increased in case of female rats, but it was not affected by the protein and energy levels in case of male rats. From the above-mentioned experimental results it may be con eluded that the best formula of diet of growing female rats may be composed of low protein (13%) and high energy levels (4000 kcal/kg) whereas that for male rats may be composed of low protein (13%) and medium energy levels (3600 kcal/kg), since all the efficiencies of food, protein and energy have shown to be best at these levels.

• Proceedings of the Korean Nutrition Society Conference
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• 2002.05a
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• pp.96-96
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• 2002

• Proceedings of the Korean Nutrition Society Conference
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• 2001.11a
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• pp.60-60
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• 2001

• Nutritional Sciences
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• v.8 no.2
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• pp.89-96
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• 2005

To determine the deleterious effects of chronic alcohol consumption on bone especially in adolescents or young adults, 8 week-old Sprague Dawley male rats were fed with Lieber-Decarli ethanol liquid diet, containing $36\%$ of energy as ethanol, ad libitum (ethanol group) or isocaloric normal liquid diet (control group) for 7 weeks. Body weight was significantly lower in ethanol group than that in control group after 1 week of feeding to the end. liver weight and the ratio of liver or kidney weight to body weight in ethanol group were significantly increased when compared to those in control group. Ethanol group showed significantly lower serum protein and albumin levels (p<0.05), higher total cholesterol and HDL-cholesterol levels (p<0.05), and AST, ALT and BUN activities than control group, but serum triglyceride, Ca and phosphate levels were not different. Ethanol group had significantly lower tibial trabecular bone area and serum osteocalcin level than control group (p<0.05), but urinary Ca and NTx (cross-linked N-telopeptide of type I collagen) concentrations and serum testosterone and parathyroid hormone levels were not different. In conclusion, chronic alcohol consumption in growing young male rats may result in osteopenia through the reduction of bone formation as well as liver malfunction.