• Nutritional Sciences
• /
• v.6 no.1
• /
• pp.25-30
• /
• 2003

The effects of soy-isoflavones, which are phytoestrogens derived from plants with a flavonoid structure, on cyclooxygenase -2 (COX-2) expression, PGE2 production, and mapkinases expression, were investigated in experimentally-induced atherogenic rats by feeding a high fat-high cholesterol diet. Female Sprague-Dawley rats were bilaterally ovariectomized; sham-operated animals were used as controls. Three weeks later, the animals were randomized to the following treatments for an eight-week experimental period: 17$\beta$-estradiol (200$\mu$ g/kg diet), low concentration of isoflavones (0.8g/kg diet), and high concentration of isoflavones (4.0g/kg diet). In the group supplemented with a high dose of isoflavones, COX-2 expression was down-regulated. This down-regulation was accompanied by a reduced expression of pERK1/2. In the second experiment using 48-week old female Sprague-Dawly rats, the effects of isoflavones and estrogen were compared in the basal estrogen-supplementation at the level of 600$\mu$ g/kg diet. Isoflavones induced the marked down-regulation of COX-2 protein and the decrease in $PGE_2$ production in estrogen supplemented states and this was followed by the down-regulation of p38 among mapkinases. The two different mapkinases are involved in the down-regulation of COX-2 depending on estrogen-deficient and estrogen supplemented states. This kind of COX-2 down-regulation by isoflavones was not observed in the different tissue, mammary glands. Further investigations on the relationship between COX-2 and biological activities such as vasodilation by isoflavonesin the absence or the presence of estrogen ave required in vivo system of female rats.

• Microbiology and Biotechnology Letters
• /
• v.39 no.3
• /
• pp.224-237
• /
• 2011

For establishing the efficacy against breast cancer occurrence, women's mammographic breast density and hot flush remission related to pre and post-menopausal symptoms were selected as biomarkers. Meta analysis applied the final selection of 40 papers from Medline to assess the efficacy of isoflavone-rich soy or supplements versus placebo under randomized controlled trials. Interestingly, the exposure to the purified isoflavones was more effective than the exposure to the crude extract of soy isoflavones for hot flush suppression. The length and the amount of dosage dependency is the most appropriately suggested to be one year long with 50~100 mg/day of isoflavone-rich soy or supplements. Funnel plots was used to interpret the results, overall effect of isoflavones on breast density in post-menopausal women was revealed to be less effect [effect size: 0.062, 95% confidence interval (CI): 0.005 to 0.12], than that of pre-menopausal women (effect size: 0.101, CI: -0.003 to 0.205). The reason why breast density was found higher among the pre-menopausal than the post-menopausal women is that the phytoestrogens of dietary isoflavones were antagonized against estrogen by the basis of estrogen receptor binding affinity. Overall, the Meta analysis reported that isoflavone had limited influence on breast density by suppressing the expansion by only 2%, while it was more effective to suppressing the hot flush, showing a dramatic decrease of 23%.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2000.11a
• /
• pp.97-99
• /
• 2000

Considerable beneficial effects on osteoporosis from soy intake in postmenopausal women are being reported (Murkies et al.1998, Arjmandi et al. 1996). Isoflavones(IF), one of phytoestrogenic substances in the soybean, have been suggested for the effect. Our preliminary study showed that even the young chicks fed IF-rich diet tended to have higher bone ash content than those fed IF-poor diet. IF have been reported to decrease bone ash content than those fed IF-poor diet, IF have been reported to decrease bone loss by reducing bone resorption. Soybean meal has been one of the most important protein sources in poultry diets. We assume that the IF intake through dietary soybean meal could give meaningful influences on the birds. This study was carried out to determine effects of dietary IF from soybean sources on bone development in young chicks. Soy protein concentrate (SPC, IF-poor)and an IF concentrate(Phyto-Nutramin) were formulated together with purified-type ingredients to provide three different levels(25, 240 and 480 mg/kg) of total IF. Control diet(240 mg/kg) was prepared with isolated soyprotein(ISP, IF-rich). The diets were fed to 96, 3-day old, layer-type, male chicks, divided into 4 treatments with 3 replications for 3 weeks. Chicks fed the ISP diet had better gain/feed ratios than fed the SPC diets. Birds fed the diets with higher levels of IF tended to show higher values in serum total and ionized Ca% and tibial bone density, length % ash, stiffness and strain. This trend however, appeared less significant at the end of third week. No noticeable differences in sizes of comb and testicle and serum alkaline phosphatase activities were observed among the dietary groups. These results suggest that dietary isoflavones from soybean sources could be associated with chemical composition and physical properties of bone in sizes of comb and testicle and serum alkaline phosphatase activities were observed among the dietary groups. These results suggest that dietary isoflavones from soybean sources could be associated with chemical composition and physical properties of bone in young chicks.

• Korean Journal of Food Science and Technology
• /
• v.30 no.4
• /
• pp.745-750
• /
• 1998

Soybean isoflavones known as an anticarcinogenic factor were evaluated in some Korean soybean foods by high performance liquid chromatography. Unfermented soybean foods contained predominantly isoflavone ${\beta}-glycosides$ (genistin and daidzin), but in the fermented soybean foods isoflavones were present mainly as aglycones (genistein and daidzein). Average contents of isoflavones of tofu, soymilk and soy sprout were 1, 151, 676 and 424 mg/kg, respectively. Among the fermented soybean products, soybean paste (Chongkukjang) was highest in the isoflavone content (920 mg/kg) and the degree of hydrolysis of ${\beta}-glycosidic$ bonds was ranged from 30 to 100%. Doenjang, Chunjang and Kanjang contained lesser amounts of isoflavones and their contents were 627, 291 and 10 mg/kg, respectively. Korean traditional fermented foods, Chongkukjang and Doenjang could be regarded as the excellent sources of soy isoflavone aglycones.

• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.3
• /
• pp.539-547
• /
• 2015

This study investigated elementary school students' perception and recognition of soybean foods and assessed their intake levels of isoflavones. A survey was administered to 300 sixth grade students in Daegu. The amount of isoflavones consumed by students was estimated by food intake frequency and the 24-hour recall method based on their general dietary habits and perception of soybean foods. Subjects' mean height was 152.2 cm, mean weight was 45.2 kg, and body mass index was $19.4kg/m^2$. All subjects had knowledge of soybeans and most preferred bean-paste pot stew of all soybean-based foods. Students typically ingested isoflavones two or three times per week in the forms of tofu, bean-paste pot stew, and bean sprouts. The average amount of isoflavones consumed from soy foods was 26.43 mg/day (daidzein 9.27 mg/day and genistein 17.16 mg/day) as assessed by food frequency questionnaire and 30.83 mg/day (daidzein 13.63 mg/day and genistein 16.40 mg/day) by the 24-hour recall method, showing that the 24-hour recall method assessment amount was 4.4 mg higher than that of the food frequency questionnaire. The major food sources of isoflavones were soybean paste and soybeans. Those who were especially knowledgeable about soybean foods expressed the view that these sources were a good or affordable enriched source of isoflavones.

• Journal of Nutrition and Health
• /
• v.36 no.5
• /
• pp.476-482
• /
• 2003

We studied the effects of soy isoflavone supplements on bone metabolism marker (serum osteocalcin, urinary deoxypyridinoline) and urinary mineral excretion (urinary Ca, Mg, Zn) in 47 postmenopausal women. There were 24 participants in the treatment group and 23 in the control group. The treatment group consumed isoflavone extract capsules daily (which contained 90 mg of soy isoflavones) for 12 weeks. The study compared before and after isoflavone intake in the following areas: Physical examination, diet survey, bone metabolism marker and urinary mineral excretion. The average age of the treatment group was 64.6 years and that of the control group was 66.5 years. There were no significant differences between the two groups in terms of height, weight and body mass index. Both groups maintained a regular diet pattern in terms of their average daily nutrient intake. There were no significant differences between the treatment group (23.9 mg) and the control group (25.4 mg) in terms of daily isoflavone intake based on diet. The analysis of bone metabolism marker changes in the treatment group after 12 weeks of taking the isoflavone supplements demonstrated significant differences in the following: Serum osteocalcin (13.7 ng/mL in befor versus 6.8 ng/mL in after) and urinary deoxypyridinoline (5.9 nmol/mmol Cr in befor versus 4.5 nmol/mmol Cr in after). The subjects in the treatment group showed no significant difference in urinary Ca excretion. But the subjects showed a significant difference in urinary Mg (131.9 mg/day in befor versus 115.6 mg/day in after) and Zn (400.5 $\mu\textrm{g}$/day in befor versus 310.2 $\mu\textrm{g}$/day in after) excretion in the isoflavone treatment group at the levels of p<0.001, p<0.01, respectively. No changes were made in the intake of minerals. The composition of serum osteocalcin and urinary deoxypyridinoline, and indicators of bone metabolism, including the excretion Mg and Zn, significantly decreased. As a result, bone mineral loss was lessened. (Korean J Nutrition 36(5): 476~482, 2003)

• Korean Journal of Food Science and Technology
• /
• v.32 no.6
• /
• pp.1266-1270
• /
• 2000

Quality properties of soy bean pastes made with Aspergillus oryzae and 5 Bacillus strains isolated from traditional soy bean pastes were examined. The pH decreased gradually and contents of amino-type nitrogen increased during fermentation. There were small differences in moisture and crude-protein contents, whereas big difference was observed in reducing sugar, isoflavones and organic acid contents. Isoflavones in the samples made with Bacillus licheniformis F2358 and Bacillus subtilis F2362 were high. Samples made with Bacillus licheniformis F2382 had high contents of organic acid and good score for taste and overall acceptability in sensory evaluation.

• The Korean Journal of Food And Nutrition
• /
• v.19 no.4
• /
• pp.460-465
• /
• 2006

This study was conducted to investigate the isoflavone contents including daidzein and genistein in soy sauces made with whole grain soybean Meju(WGSM), comparing with defatted Meju(DM) du.ins fermentation. Total isoflavone contents in 2 soy sauces made with DM, Control and product A, increased with period of fermentation and were 15 and 4.3 times higher after 180 days of fermentation than on the day before fermentation respectively. Meanwhile, 2 soy sauces made with WGSM, product B and C, had the highest amounts with $20.53{\mu}g/g\;and\;19.52{\mu}g/g$ of isoflavones on the day before fermentation respectively, and then decreased with fermentation time. High amounts of isoflavones were detected in 20 days of fermentation of soy sauce which made with WGSM and wheat Meju(product D). Daidzein was the largest amounts in isoflavone contents, regardless of total or free isoflavone types. The level of daidzein increased with fermentation time in 2 soy sauces made with DM, Control and product A, whereas 2 soy sauces made with WGSM, product B and C decreased with fermentation time, instead of increasing of genistein contents.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.2
• /
• pp.137-142
• /
• 2007

This study was carried out to observe the antioxidant and angiotensin converting enzyme (ACE) inhibitory activity of susijang (Korean traditional fermented soy food). The antioxidant activity of susijang was measured by using TEAC (trolox equivalent antioxidant capacity) assay. In addition contents of isoflavones, phenolic acids and amino acids were determined. TEAC values of chungkukjang and susijang were significantly higher than those of yellow soybean (p<0.05). The contents of isoflavones (genistein, daidzein) were found to be significantly higher in chungkukjang and susijang than yellow soybean. The susijang showed high content of free amino acids and phenolic acids. ACE inhibitory activity of susijang was significantly higher than those of chungkukjang and yellow soybean, particularly of 70% ethanol extract.

• Journal of Nutrition and Health
• /
• v.35 no.10
• /
• pp.1081-1088
• /
• 2002

Flavonoids are phytochemicals that occur ubiquitously in plant foods that have been reported to have potential roles in the prevention of cancer, inhibition of platelet aggregation or inflammation. However, there was no accurate data reported on the intake of middle-aged Korean population. The present study was designed to assess dietary intake of flavonoids (including isoflavones) of 304 adults (20-59 yr, male 115, famale 189) living in Daejeon area using semi-quantitative food frequency questionnaire. The questionnaire consisted of 50 food items, including vegetables, soy products, seaweeds, nuts and beans, fruits and beverages. Our self-administered questionnaire contained questions regarding subject's habitual diet and alcohol intake over the previous 3 months. Average daily intake of individual flavonols such as quercetin, kaempferol, myricetin, and flavones such as luteolin, apigenin was 15.7, 8.7, 0.21, 2.07, 0.03 mg/day, respectively. Daily intake of daidzein and genistein, which are the commonly found isoflavones in soy products, were 16.6 and 21.4 mg/day, respectively. Combined intake of flavonoids was 64.3 mg/day. No effect of smoking, drinking and exercise was observed on flavonoids consumption. Food items that has the highest daily intake of each compounds were; quercetin (onion, 9.49 mg/day), kaempferol (strawberry, 1.18 mg/day), myricetin (green tea, 0.81 mg/day), apigenin (lettuce, 0.03 mg/day), luteolin (onion, 0.05 mg/day), daidzein (soybean sprout, 5.99 mg/day), genistein (soybean sprout, 7.02 mg/day). These findings provide valuable information on understanding the dietary flavonoids intake from a typical Korean daily diet, which might help to identify the risks for developing various diseases.