• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1252-1257
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• 2007

This study was conducted to determine the effect of dietary soy isoflavone (ISF, 0 and 20 mg/kg) on performance, meat quality and antioxidative property in male broilers. Six replicates of 45 birds (42 d old) were used for each treatment. The birds were fed soybean meal-free diets containing 3% oxidized fish oil (acid value, 6.76 mg potassium hydroxide/g; and peroxide value, 6.18 meq/kg) for 3 wk. The results showed that average daily gain, feed intake, feed conversion and carcass traits were not affected by soy ISF. Compared with the control group, breast muscle color redness value and water holding capacity were increased (p<0.05) by ISF supplementation. The activity of plasma catalase was increased by supplementing with 20 mg ISF/kg diet. In breast muscle, Broilers fed 20 mg ISF/kg had decreased production of malondialdehyde and lactic acid. The ISF supplementation elevated total antioxidative capacity and activities of total superoxide dismutase and glutathione peroxidase. The results indicated that dietary ISF could increase redness and water holding capacity of meat, and antioxidative property of meat in male broilers fed oxidized fish oil diet.

• Journal of Applied Biological Chemistry
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• v.48 no.2
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• pp.49-57
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• 2005

Soy is an important food in Asia and many studies have suggested that the low incidences of chronic diseases in Asian countries are associated with diets that are rich in soy. Soy contains many kinds of phytochemicals, and soy isoflavones and soyasaponins have received considerable attention. Twelve isoflavone components have been isolated from soy: three aglycones (daidzein, genistein, and glycitein), and their respective nine glucosidic conjugates. Soy isoflavones are similar in structure to estrogen and exhibit both estrogenic and antiestrogenic activities. Soy isoflavones exhibit anticancer activity, can reduce the risk of cardiovascular disease, and are beneficial to brain and bone health. Soyasaponins are divided into three groups (A, B, and E saponins), and they exhibit hypocholesterolemic, anticancer, hepatoprotective, antioxidative, and anti-human-immunodeficiency-virus effects. Despite the abundant literature suggesting that soy isoflavones and soyasaponins have potential applications in preventive medicine, further research is needed to standardize dosages and ensure their efficacy.

• Nutritional Sciences
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• v.9 no.4
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• pp.240-247
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• 2006

In this study we investigated the neuroprotective, antioxidative, and hypocholestrolemic effects of dietary soy protein and soy isoflavone in a rat focal brain ischemia model. Weaning Sprague-Dawley rats were fed a 20% casein-based diet (CA), 20% soy protein-based diet (SP), or 0.2% soy isoflavones-supplemented diet (ISO) for 6 weeks. The cortical infarction volume of the ISO group was significantly lower than that of the SP group. The thiobarbituric acid reactive substances (TBARS) were considerably lower in the ISO group than the CA group. Glutatbione peroxidase activities of the SP group were notably higher than those of the CA group. Acetylcholinesterase (AchE) activities of the SP group were significantly decreased compared to the CA group. LDL cholesterol levels and LDL/HDL ratios of the ISO group were lower than those of the CA and SP groups. Our results collectively suggest that soy isoflavones may contribute to neuroprotection by reducing the TBARS and serum LDL/HDL ratio, whereas soy protein may be associated with the regulation of cognitive functions by modulating AchE activity.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.212.3-213
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• 2003

Polyphenolic compounds including flavonoids are wide spread in the plant kingdom, and interested recently because epidemiological studies have suggested correlations between the consumption of polyphenol-rich plant foods and the prevention of chronic diseases. Soy is a main source of isoflavonoids which are high dietary intake for the oriental population. In this study, anti-inflammatory action of sophoricoside, an isoflavone glycoside isolated from immature fruits of Sophora japonica (Leguminosae family), has been demonstrated. (omitted)

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.134-146
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• 2022

BACKGROUND/OBJECTIVES: Accumulating evidence has shown the beneficial effects of isoflavone on health. There is limited information on the usual isoflavone intake for Koreans. This study examined the usual intake of total isoflavone and its major food sources in Koreans according to age and gender. SUBJECTS/METHODS: The dietary intake data of 21,271 participants aged 1 yrs and older from the Korea National Health and Nutrition Examination Survey (KNHANES) VII 2016-2018 were analyzed. The average isoflavone intake was estimated based on the 24-h dietary recall data in KNHANES and the isoflavone database from the Korea Rural Development Administration (RDA) and literatures. The usual isoflavone intake was estimated by applying the ratio of within- and between-participant variance estimated from the 2009 KNHANES data to the 7th KNHANES (2016-2018) data. The variance of the isoflavone intake was calculated using MIXTRAN macro with intake data for two days in the 2009 KNHANES. Complex sample analysis with stratified variables and integrated weights was conducted. RESULTS: The mean total isoflavone intake in the Korean population aged 1 yrs and older (n = 21,271) was 139.27 mg/d, which was higher than the usual intake of 47.44mg/d. Legumes were a major contributing food group (91%), with arrowroot being a major individual contributor to the isoflavone intake (67.2%), followed by 21.3% of soybean, 5.4% of bean sprouts, and 2.1% of tofu. The usual isoflavone intake was highest in the participants aged 50 to 64 yrs old and increased with age until 50 to 64 yrs and then decreased with further increases in age. The usual isoflavone intake of participants aged 65 yrs and older was higher for men than for women, showing gender differences. CONCLUSIONS: The usual dietary intake of isoflavone varied according to age and gender in the Korean population. This study showed that the usual isoflavone intake was lower than the average isoflavone intake. The difference between percentiles of the usual isoflavone intake was similarly smaller than the average intake. An estimation of average intake can be hindered by the occasional consumption of foods high in isoflavones, suggesting that the usual intake estimation method can be more appropriate. Further research will be needed to establish isoflavone dietary guidelines regarding the effects of isoflavone intake on health outcomes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.833-839
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• 2005

This study was conducted to demonstrate whether dietary Ca and the soy isoflavones supplementation could reduce the bone loss associated with estrogen deficiency. Nine week-old female rats (SD) were ovariectomized and then fed on diet of low $(0.1\%)$ or normal $(0.5\%)$ Ca supplemented with soy isoflavones (80 and 160 ppm) for 6 weeks. The ovariectomized and sham-operated rats showed normal serum Ca and P levels, and dietary Ca and soy isoflavones did not changed them. The serum alkaline phosphatase activity was increased in all ovariectomized rats, especially in the rats fed low Ca diet regardless of isoflavone supplementation. The serum tartrate-resistance acid phosphatase was not significantly different among the ovariectomized rats and were not changed by dietary Ca and isoflavones. Breaking force of femur was higher in the rats fed the nomral Ca diets and not statistically changed by soy isoflavone supplementation. Femoral and lumbar Ca and P contents decreased in the ovariectomized rats and the soy isoflavones-80 ppm supplementation significantly enhanced bone minerals, but the soy isoflavones-160 ppm supplementation did not. Dietary Ca increased lumbar Ca and P contents. The results of this study have suggested that the soy isoflavones 80 ppm supplementation could be sufficient to prevent bone loss in ovariectomized rats and normal Ca supplementation could enhance the effect of soy isoflavones on bone protection.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.371-385
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• 2023

BACKGROUND/OBJECTIVES: Soy isoflavone (SIF) and soy lecithin (SL) have beneficial effects on many chronic diseases, including neurodegenerative diseases. Regretfully, there is little evidence to show the combined effects of these soy extractives on the impairment of cognition and abnormal cerebral blood flow (CBF). This study examined the optimal combination dose of SIF + SL to provide evidence for improving CBF and protecting cerebrovascular endothelial cells. MATERIALS/METHODS: In vivo study, SIF50 + SL40, SIF50 + SL80 and SIF50 + SL160 groups were obtained. Morris water maze, laser speckle contrast imaging (LSCI), and hematoxylin-eosin staining were used to detect learning and memory impairment, CBF, and damage to the cerebrovascular tissue in rat. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the oxidized glutathione (GSSG) were detected. The anti-oxidative damage index of superoxide dismutase (SOD) and glutathione (GSH) in the serum of an animal model was also tested. In vitro study, an immortalized mouse brain endothelial cell line (bEND.3 cells) was used to confirm the cerebrovascular endothelial cell protection of SIF + SL. In this study, 50 µM of Gen were used, while the 25, 50, or 100 µM of SL for different incubation times were selected first. The intracellular levels of 8-OHdG, SOD, GSH, and GSSG were also detected in the cells. RESULTS: In vivo study, SIF + SL could increase the target crossing times significantly and shorten the total swimming distance of rats. The CBF in the rats of the SIF50 + SL40 group and SIF50 + SL160 group was enhanced. Pathological changes, such as attenuation of the endothelium in cerebral vessels were much less in the SIF50 + SL40 group and SIF50 + SL160 group. The 8-OHdG was reduced in the SIF50 + SL40 group. The GSSG showed a significant decrease in all SIF + SL pretreatment groups, but the GSH showed an opposite result. SOD was upregulated by SIF + SL pretreatment. Different combinations of Genistein (Gen)+SL, the secondary proof of health benefits found in vivo study, showed they have effective anti-oxidation and less side reaction on protecting cerebrovascular endothelial cell. SIF50 + SL40 in rats experiment and Gen50 + SL25 in cell test were the optimum joint doses on alleviating cognitive impairment and regulating CBF through protecting cerebrovascular tissue by its antioxidant activity. CONCLUSIONS: SIF+SL could significantly prevent cognitive defect induced by β-Amyloid through regulating CBF. This kind of effect might be attributed to its antioxidant activity on protecting cerebral vessels.

• Journal of Menopausal Medicine
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• v.24 no.3
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• pp.176-182
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• 2018

Objectives: Menopause is associated with adverse metabolic changes in plasma lipoprotein and inflammation markers. Estrogens have beneficial effects on lipid metabolism and inflammation. Isoflavones (ISO) have structurally similar to estradiol. Our objective was analize the effect of soy-ISO on serum lipid and inflammatory markers (sP-selectin and sCD40L) in postmenopausal women. Methods: A 12-week randomized, double-blind, placebo-controlled intervention with soy-ISO (50 mg, twice daily) was conducted in 35 healthy postmenopausal women (55-72 years old). The women were divided in 2 groups: 20 were allocated to soy-ISO, and 15 to a placebo group. Results: The changes of total cholesterol (TC), triglycerides, low-density lipoproteins-cholesterol (LDL-C), high-density lipoprotein-cholesterol, Apo-A1, sP-selectin and sCD40L in 2 groups before and after 12-week treatment showed no statistical significance. In subgroup analysis, soy-ISO supplementation significantly decreased the levels of TC, LDL-C and sCD40L in women under 65 years old, and with null effects on serum lipid and inflammation markers in women over 65 years old. Conclusions: Soy-ISO did not significantly favorable effects on the lipid profile and inflammatory markers in postmenopausal women. However, in women under 65 years of age, soy-ISO significantly decreased the TC, LDL-C and sCD40L, whereas, no effects on lipid profile and inflammation markers in women over 65 years old were observed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.27-35
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• 2005

This study was performed to determine the effect of three different concentrations of soy-isoflavones on excretions through urine and feces in either sham-operated or ovariectomized female rats. Seventy-two 16-week old Sprague-Dawley rats underwent sham operation or bilateral ovariectomy. They were provided diets containing different levels of soy isoflavones for 6 weeks: 50 ppm (low isoflavone intake; LI), 250 ppm (medium isoflavone intake; MI) and 500 ppm (high isoflavone intake; HI). The subsequent fecal and urinary excretions of daidzein and genistein were then measured. In the sham operated rats, body weight gains and food efficiency ratio of the MI and HI groups were significantly lower than control group, while food intake was not different. However, there was no significant difference in ovariectomized rats. The fecal excretion of daidzein was significantly higher in the HI group than the LI and MI groups, and that of genistein increased as dietary isoflavone intakes increased in both the sham operation and ovariectomy. The reverse tendency of fecal recovery was shown with dietary isoflavone dose only in genistein among ovariectomized rats. When dietary isoflavones were increased from 50 ppm to 500 ppm, the amounts of daidzein and genistein in the urine increased dose-dependently. The higher intakes of isoflavones leaded to lower recovery rates of daidzein and genistein in the urine in the sham-operated rats but not in the ovariectomized rats. The urinary recovery was significantly higher in the LI group than the MI and HI groups in the sham-operated rats. The excreted amounts and recovery of the two isoflavones in the urine were higher in the sham operated groups than in the ovariectomized groups, which implied an increased bioavailability of isoflavones by ovariectomy. Therefore, the results suggest that a more efficient use of soy isoflavones in ovariectomized conditions may occur, which indicates that a higher dose of soy isoflavones is necessary for the postmenopausal states.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1046-1050
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• 2009

Our previous study showed that isoflavone profile of soybean undergoes a significant change during cheonggukjang preparation. In particular, the content of metabolite(s) with similar retention time to glycitein under the high performance liquid chromatography (HPLC) condition was significantly increased while the levels of genistein and its derivatives were notably lowered. Therefore, we hypothesized that genistein and its derivatives might be converted to genistein glucosides with similar elution time to glycitein. Our current data suggest that genistein and its derivatives are extensively metabolized into various compounds including genistein glycosides, but not glycitein or its derivatives, by Bacillus species isolated from traditional cheonggukjang. Some of daidzein was also converted into a derivative with shorter retention time by Bacillus amyloliquefaciens 51 and 86-1 but not by Bacillus subtilis 3-5 and 3-17. As metabolism of soy isoflavones, major health-promoting components in soy products, is widely variable depending upon Bacillus species, it is essential to select microorganism that minimizes the breakdown or modification of soy isoflavones in the process of fermented soy product manufacture.