Isoflavone Extract Research Articles

Modeling for extraction of isoflavones from stem of Pueraria lobata (Willd.) Ohwi using n-butanol/water two-phase solvent system

Extraction of isoflavones from stem of Pueraria lobata (Willd.) Ohwi was studied using n-butanol/water two-phase solvent system as solvents. The influence of solvent composition and temperature on the extraction kinetics was investigated. It was found that 1:1 (v/v) n-butanol/water results in the maximum yield of total-isoflavones. The higher the temperature, the higher the yield of total-isoflavones and the extraction rate. A mathematical model was proposed and solved to describe the extraction process. It was found that the calculation results are in good agreement with the experimental data.

Comment on Extraction and Purification of Isoflavones from Soybeans and Characterization of Their Estrogenic Activities

Comment on Extraction and Purification of Isoflavones from Soybeans and Characterization of Their Estrogenic Activities

Response to Comment on Extraction and Purification of Isoflavones from Soybeans and Characterization of Their Estrogenic Activities

Response to Comment on Extraction and Purification of Isoflavones from Soybeans and Characterization of Their Estrogenic Activities

Effects of extraction temperature, ionic strength and contact time on efficiency of bis(2‐ethylhexyl) sodium sulfosuccinate (AOT) reverse micellar backward extraction of soy protein and isoflavones from soy flour

AbstractBACKGROUND: Soy protein enriched with isoflavones has been linked to various disease‐preventing and health‐promoting activities owing to the antihypertensive, hypocholesterolaemic, antiobesity and antioxidative properties of isoflavones. The isoflavone profiles of soy‐based products are known to be highly dependent on the various chemical and physical treatments to which the products have been subjected. The aim of this research was to increase the efficiency of backward extraction of soy protein and isoflavones from bis(2‐ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles by studying the effects of extraction temperature, ionic strength of the aqueous stripping solution and contact time on the amounts of soy protein and isoflavones backward extracted from an AOT/H2O/isooctane reverse micellar system.RESULTS: By modifying the extraction temperature, ionic strength and contact time, 47.0–60.2% of protein, 43.3–68.4% of daidzin, 43.8–74.6% of genistin, 39.0–88.8% of glycitin, 20.8–92.6% of malonyl genistin, 20.2–52.0% of malonyl glycitin, 32.7–75.6% of acetyl genistin, 49.7–76.8% of daidzein and 19.6–38.1% of genistein present in the AOT reverse micellar solution were backward extracted into the aqueous stripping phase. Statistical analysis showed that there were significant linear and interactive effects of temperature and contact time on the backward extraction of daidzin, genistin, glycitin and daidzein. Significant linear and interactive effects of ionic strength and contact time were found in the backward extraction of daidzin and genistin. The backward extraction of genistein was only influenced by contact time and its interaction with temperature.CONCLUSION: This study showed the potential of reverse micelles as a protocol for extracting isoflavones from soy samples for analytical purposes. By modifying the extraction temperature, contact time and ionic strength, soy protein enriched with daidzin, genistin, daidzein and genistein could be produced from soy flour. The results represent an important contribution to current knowledge on utilising reverse micellar extraction in food technology. Copyright © 2007 Society of Chemical Industry

Effects of One-Year Treatment with Isoflavone Extract from Red Clover on Prostate, Liver Function, Sexual Function, and Quality of Life in Men with Elevated PSA Levels and Negative Prostate Biopsy Findings

To asses the effect of an isoflavonoid extract from red clover on the prostate, liver function, quality of life, and sexual function in men with an initial elevated prostate-specific antigen (PSA) level and negative prostate biopsy findings during a 1-year treatment period. A total of 20 men (mean age 65 years) were treated with a daily 60-mg dose of an isoflavone extract for 1 year. Liver function, sexual hormone levels (total testosterone, estrogen, luteotropic hormone, follicle-stimulating hormone, and dehydroepiandrosterone sulfate), transrectal ultrasonography volumetry of the prostate, PSA level, International Prostate Symptom Score, and International Index of Erectile Function score were recorded at the beginning of the study and every 3 months for 1 year. The average PSA level was 10.16 ng/mL at baseline versus 7.15 ng/mL after 12 months, for a statistically significant reduction of 33% (P <0.019). The mean prostate volume had decreased slightly from 49.3 cm3 to 44.3 cm3 after 12 months (P <0.097). The sexual hormone levels did not change throughout the study. We registered a significant increase in all three liver transaminases after 3 months (P <0.001). The International Prostate Symptom Score showed a mean value of 7.9 at baseline and 6.68 after 12 months (P <0.421). Sexual function was not influenced by the treatment. Daily oral administration of 60 mg of an isoflavone extract was well tolerated and caused no side effects. The significant increase in liver transaminases and the significant decrease in total PSA levels by >30% indicates that patients, general practitioners, and urologists should be informed about these potential effects of red clover extracts and possibly other phytoestrogens, on liver transaminases and elevated total PSA levels.

Developmental and Reproductive Toxicity of Soybean Isoflavones to Immature SD Rats

To investigate the dose-dependent toxic effect of soybean isoflavone extracts (SIE) on reproductive development in immature rats. Growing male and female rats (n = 50 each, 4 weeks) were divided into five groups fed with a standard cereal-based diet and gastrogavaged daily with 0, 30, 150, 300, and 600 mg SIE/kg body weight, respectively, for 12 weeks. Body weight, organ weights, and serum level of estrogen and testosterone were measured. Oral administration of SIE had no effect on food intake but decreased food efficiency ratio (P < 0.01). Suppression on body weight gain by SIE was dose-dependent and the effect was greater on male than on female rats (P < 0.01). SIE at high doses exhibited hepatotoxicity by increasing a relative liver weight, and also caused a smaller uterus but a greater relative ovary in female rats, while leading to larger relative testis and epididymis in male rats. SIE could decrease progesterone concentrations in female rats, whereas in male rats it reduced not only total testosterone level but also sperm count compared with the control group (P < 0.05). SIE at a range of 50-1000 times of human intake level affects not only growth but also development of reproductive system in growing rats.

Effects of soybean isoflavone extract on the plasma lipid profiles and antioxidant enzyme activity in streptozotocin-induced diabetic rats

The present study evaluated the effects of various dosages of soybean isoflavone extract on lipid profiles, lipid peroxidation and antioxidant activities in streptozotocin-induced diabetic rats. The one normal control group was fed an AIN-76-based experimental diet and four diabetic groups were fed the same diet, supplemented with four different levels of soybean isoflavone extract for seven weeks. The daily dosages of pure isoflavone for four diabetic groups were set to be 0 mg (diabetic control), 0.5 mg (ISO-I), 3.0 mg (ISO-II) and 30.0 mg (ISO-III) per kilogram of body weight, respectively. The plasma total cholesterol levels and the TBA-reactive substances contents in the liver and kidney were significantly lowered in ISO-II and ISO-III groups compared to those in the diabetic control group. The levels of plasma HDL-cholesterol, plasma vitamin A and hepatic superoxide dismutase were significantly increased in those two groups compared with the diabetic control group. The present study demonstrated the possibility that the diets supplemented with 3.0 mg and 30.0 mg of soybean isoflavone extract may have beneficial effects on the plasma lipids, tissue lipid peroxidation and partly on antioxidant system in diabetic animals and there were no significant differences between the ISO-II and ISO-III groups. The results suggest that the effective daily dosage level of isoflavone for improving lipid metabolism in diabetic rats may be above 3.0 mg per kilogram body weight.

고 Isoflavone 콩나물이 만성 에탄올 투여 흰쥐의 지질대사에 미치는 영향

본 연구는 고 isoflavone 콩나물이 만성 에탄올 섭취 동물에서 지질대사와 항산화 효소계에 미치는 영향을 살펴보고 기능성 식품으로서의 가능성을 알아보기 위하여 수행되었다. 실험동물은 SD계 수컷쥐를 사용하였으며 40일간 Lieber-DeCarli 액체식이를 일부 변형한 실험식을 공급하여 고 isoflavone 콩나물과 isoflavone 추출물이 에탄올 투여 흰쥐의 지질대사와 항산화효소계에 미치는 영향을 조사하여 다음과 같은 결과를 얻었다. High SS군은 알코올 대조군에 비하여 체중증가량, 식이섭취량 및 식이효율이 모두 증가되었으나, low SS군과 IE군은 전반적으로 체중증가량, 식이섭취량 및 식이효율이 알코올 대조군보다 낮았다. 고 isoflavone 콩나물과 대두 isoflavone 추출물은 알코올 투여시 증가된 혈장 TG, TC, AI를 낮추었고, HDL-chol/TC의 비를 높였으며 간조직의 총 지질량, TG, TC 수준을 낮추었다. Isoflavone 추출물은 간조직의 TBARS 수준을 유의하게 낮추었으나 간조직 항산화효소 활성도를 증가시키지는 않았으므로 isoflavone의 항산화기전에 대한 연구가 필요할 것으로 보인다. 이상의 결과로부터 고 isoflavone 콩나물과 isoflavone 추출물은 혈장과 간조직의 지질 농도와 지질과산화를 낮추며 일부 항산화 효소계에 긍정적인 효과를 미치는 것으로 보인다.

Enhanced Bioavailability of Soy Isoflavones by Complexation with β-Cyclodextrin in Rats

In order to improve the solubility and bioavailability of a soy isoflavone extract (IFE), inclusion complexes (IFE-beta-CD) of the isoflavone extract with beta-cyclodextrin (beta-CD) were prepared and studied for their solubility and bioavailability. The aqueous solubility of the complexes of IFE with beta-CD (2.0 mg/ml) was about 26 times that of IFE itself (0.076 mg/ml). The same dosages of IFE and IFE-beta-CD were orally administered to SD rats (Sprague-Dawley) on an isoflavone glycoside (IFG) basis (daidzin, genistin and glycitin), and the plasma concentrations of daidzein, genistein and glycitein were measured over time to estimate the average AUC (area under the plasma concentration versus time curve) of the isoflavones. After the oral administration, the AUC values for daidzein, genistein and glycitein were 340, 11 and 28 microg x min/ml, respectively. In contrast, the respective AUC values after the administration of IFE-beta-CD were 430, 20 and 48 microg x min/ml. The bioavailability of daidzein in IFE-beta-CD was increased to 126% by the formation of inclusion complexes with beta-CD, compared with that in IFE. Furthermore, the bioavailability of genistein and glycitein in IFE-beta-CD formulation was significantly higher by up to 180% and 170%, respectively, compared with that of IFE p=0.008 and p=0.028, respectively). These results show that the absorption of IFE could be improved by the complexation of IFE with beta-CD (IFE-beta-CD).

Ultrasonically Assisted Extraction of Isoflavones from Stem of Pueraria lobata (Willd.) Ohwi and Its Mathematical Model

Ultrasonically assisted extraction of isoflavones from the stem of Pueraria lobata (Willd.) Ohwi has been carried out with an ultrasonic extracting apparatus (20kHz, electrical power input to the transducer in 0—650W). The influence of the electrical power input and extraction time on the extraction yield is investigated in water, n-butanol, and 95% (by volume) and 50% (by volume) ethanol aqueous solution. The experimental results indicate that the yields of total isoflavones are higher in Ultrasonically assisted extraction than those obtained from conventional extraction. Moreover, a mathematical model is proposed, by introducing the electrical power input to index the ultrasound intensity, to describe the behavior of ultrasonically assisted extraction. It is found that the model calculations are in good agreement with the experimental data.

Endometrial safety assessment of a specific and standardized soy extract according to international guidelines

To assess the effects of an oral soy isoflavone extract (Phytosoya) on endometrium (evaluated by biopsy and ultrasonography) in postmenopausal women treated for 12 months. A total of 395 postmenopausal women were included in this international prospective, open-label study. The women were treated for 12 months with a specific standardized soy isoflavone extract (total of 70 mg/d). Endometrial biopsy and transvaginal ultrasonography were performed before and after 12 months of treatment according to European guidelines. A total of 301 assessable biopsy specimens were obtained from women treated for 12 months; the results were 99.67% atrophic/inactive endometrium and 0.33% proliferative endometrium. No case of hyperplasia or carcinoma was diagnosed, demonstrating the endometrial safety of this extract (point estimate: 0.0; upper limit of 95% CI: 0.012). Endometrial thickness did not show any increase after 12 months of treatment (2.2 mm at inclusion and 2.12 mm at the end of the study). Only eight women reported some kind of bleeding as an adverse event during the study. These results of endometrial biopsy and endometrial thickness suggest that daily administration of 70 mg of a specific and standardized isoflavone extract for 12 months does not stimulate the endometrium.

Antiproliferation of Hepatoma Cell and Progression of Cell Cycle as Affected by Isoflavone Extracts from Soybean Cake

The objectives of this study were to isolate various isoflavone fractions andextracts from soybean cake by preparative column chromatography and compare themwith isoflavone standards with regards to inhibition of HepG2 cancer cell proliferation.Four fractions, including malonylglucoside, glucoside, acetylglucoside and aglycone, andtwo isoflavone extracts, ISO-1 and ISO-2, were collected for evaluation. MTT test resultsshowed that most treatments were slightly protective against HepG2 cell growth at a lowdose of isoflavone (5 and 10 μg/mL). However, at elevated concentration of isoflavone(20-50 μg/mL), both aglycone and acetylglucoside fractions as well as a mixture ofisoflavone standards were the most effective in inhibition, demonstrating a possiblesynergistic phenomenon. Genistein showed a better retardation effect than daidzein. Forcell cycle analysis, both aglycone and acetylglucoside fractions and a mixture ofisoflavone standards exhibited a high G2/M ratio, correlating well with the result of MTTtest. The presence of some other functional components in soybean cake like saponinsand phenolic compounds may also play a vital role in inhibiting HepG2 cell growth.

Proteomic biomarkers of peripheral blood mononuclear cells obtained from postmenopausal women undergoing an intervention with soy isoflavones

Background: The incidence of cardiovascular diseases increases after menopause, and soy consumption is suggested to inhibit disease development.Objective: The objective was to identify biomarkers of response to a dietary supplementation with an isoflavone extract in postmenopausal women by proteome analysis of peripheral blood mononuclear cells.Design: The study with healthy postmenopausal woman was performed in a placebo-controlled sequential design. Peripheral mononuclear blood cells were collected from 10 volunteers after 8 wk of receiving daily 2 placebo cereal bars and after a subsequent 8 wk of intervention with 2 cereal bars each providing 25 mg of isoflavones. The proteome of the cells was visualized after 2-dimensional gel electrophoresis, and peptide mass fingerprinting served to identify proteins that by the intervention displayed altered protein concentrations.Results: Twenty-nine proteins were identified that showed significantly altered expression in the mononuclear blood cells under the soy-isoflavone intervention, including a variety of proteins involved in an antiinflammatory response. Heat shock protein 70 or a lymphocyte-specific protein phosphatase and proteins that promote increased fibrinolysis, such as α-enolase, were found at increased intensities, whereas those that mediate adhesion, migration, and proliferation of vascular smooth muscle cells, such as galectin-1, were found at reduced intensities after soy extract consumption.Conclusion: Proteome analysis identified in vivo markers that respond to a dietary intervention with isoflavone-enriched soy extract in postmenopausal women. The nature of the proteins identified suggests that soy isoflavones may increase the antiinflammatory response in blood mononuclear cells that might contribute to the atherosclerosis-preventive activities of a soy-rich diet.

고이소플라본 콩나물의 고지혈증 개선효과

본 연구에서는 선행연구에서 우량 콩나물로 선별된 이소플라본을 다량 함유한 콩나물의 투여가 실험적으로 유발된 고지혈증 흰쥐의 지질대사에 미치는 효과를 조사하였다. 고지혈증은 SD계 흰쥐에 cholesterol 0.5%, lard 9.3%, sodium cholate 0.2%를 함유한 AIN standard식이에 의해 유발되었다. 실험군은 정상 대조군, 고지혈증 대조군, 고지혈증 유발식이에 1%, 5% 콩나물 분말, 또는 0.2% 대두 이소플라본 추출물 보충군으로 하였다. 실험식을 4주간 투여한 후 혈장지질과 과산화물 수준, 간조직의 항산화효소 활성도, 혈장 항산화 영양소 수준을 측정하여 다음과 같은 결과를 얻었다. 콩나물분말의 보충 투여는 고지혈증 동물의 식이효율(0.33～0.34)에 영향을 미치지 않았으며 고지혈증 쥐에서 혈장 중성지질의 저하 경향을 보였으며 총 콜레스테롤 농도의 유의적인 저하효과를 나타내었다. 또한 콩나물 분말 투여는 고지혈증 동물들에서 투여량에 관계없이 혈장과 간, 신장, 심장 등 조직 중의 지질과산화물 수준을 낮추는 경향을 보였으나 그 저하효과는 대두 이소플라본 추출물의 효과보다는 낮았다. Catalase와 glutathione peroxidase 등 항산화효소들의 활성도는 고이소플라본콩나물의 투여로 대조군에 비해 유의적이지는 않았지만 증가되는 경향을 나타냈으며 혈장의 vitamin A 수준은 5% 콩나물 투여군에서 유의적으로 높았고 vitamin E 수준은 유의적인 차이가 없었다. 이상의 결과로부터 이소플라본이 풍부한 콩나물의 투여는 고지혈증 동물에서 혈중지질 개선효과가 대두 이소플라본 추출물의 효과와 유사하거나 더 높은 것으로 나타났으며, 유의적이지는 않았으나 조직중 지질과산화물생성을 억제하고 항산화영양소 수준을 높이는 경향을 나타내었다. 이와 같은 결과는 본 실험에서 사용한 콩나물 시료가 높은 이소플라본 함량이외에도 식이섬유를 다량 함유하고 있으므로 섬유에 의한 부가적인 효과에 의한 것으로 추정되며 콩나물의 영양적 우수성을 일부 입증한 결과로 평가된다.

Efficacy and safety of a soy isoflavone extract in postmenopausal women: A randomized, double-blind, and placebo-controlled study

ObjectiveTo investigate the efficacy of soy isoflavone on climacteric symptoms in postmenopausal women. DesignIn this double-blind, randomized, placebo-controlled study, a total of 80 women (mean age=55.1 years), who reported 5 or more hot flush episodes per day, were randomized to receive either 250mg of standardized soy extract (Glycine max AT) a total of 100mg/day of isoflavone (n=40) or placebo (n=40). Exclusion criteria included: contra-indication for hormone therapy (HT), chronic gastrointestinal diseases, and users of HT within the preceding 6-months. For 10-months, climacteric symptoms were evaluated using a score card and the menopausal Kupperman index. Compliance and safety were also assessed. At baseline and the end of the study, lipid and hormonal profiles, as well as vaginal, mammographic and ultrasonographic parameters were measured. The t-test, Wilcoxon test and ANOVA were used in the statistical analysis. ResultsAt baseline, the mean number of hot flushes was 9.6±3.9 per day in the isoflavone group and 10.1±4.9 in the placebo group (p>0.05). After 10 months, there was a significant reduction in frequency of hot flushes among isoflavone users when compared to those on placebo (3.1±2.3 and 5.9±4.3, respectively) (p<0.001). Kupperman index mean values showed a significant reduction in both groups. However, soy isoflavone was significantly superior to placebo, in reducing hot flush severity (69.9% and 33.7%, respectively) (p<0.001). Endometrial thickness, mammography, vaginal cytology, lipids and hormonal profile did not change in both groups. No serious adverse event related to isoflavone treatment was reported. ConclusionsThe soy isoflavone extract exerted favorable effects on vasomotor symptoms and good compliance, providing a safe and effective alternative therapeutic for postmenopausal women.

Extraction and Purification of Isoflavones from Soybeans and Characterization of Their Estrogenic Activities

Soybean isoflavones have multiple beneficial health effects especially on estrogen-deficient diseases such as menopausal symptoms. In this study, isoflavones were produced from soybean flour, and the extraction and purification parameters were optimized to give a high yield of total isoflavones, about 0.62 mg of aglycones/g of soybean flour, which is >2 times the initial yield. HPLC analysis and MTT cell proliferation assay using MCF-7 cells revealed that the product thus obtained not only contained a high content of isoflavone aglycones but also had estrogenic activity. MTT data also revealed that both genistein and daidzein exhibited estrogenic effects at lower concentrations and antiproliferative effects at higher concentrations, and 1 microM genistein and 10 microM daidzein exerted significant estrogenic activities, which were not more than that of the endogenous level of 17beta-estradiol (E2). The production method developed can be used as a guideline for manufacturing soy isoflavones, and the MTT assay was demonstrated to be suitable for quality control on isoflavone products. The results on the estrogenic properties of isoflavones can be used as reference data for their effective and safe usages in estrogenic therapy.

UVB-Protective Effects of Isoflavone Extracts from Soybean Cake in Human Keratinocytes

It has been shown by chromatography that aglycone, glucoside, acetylglucosideand malonylglucoside isoflavone extracts prepared from soybean cake showed betterantioxidant activities than isoflavone standards. Consequently, the aim of this study was toevaluate the protective effects of these isoflavone extracts against ultraviolet B (UVB)-induced keratinocyte damage. Our results demonstrated that these soybean cake isoflavoneextracts could inhibit UVB-induced keratinocyte death. Moreover, they could inhibit UVB-induced intracellular release of hydrogen peroxide (H2O2) Furthermore, these isoflavoneextracts differentially inhibited UVB-induced MAPK phosphorylation. The ERK1/2 andp38 phosphorylation was not inhibited by all tested isoflavone extracts, whereas JNKphosphorylation was inhibited by group I to group III isoflavone extracts. Since theseisoflavone extracts are relative stable and easily obtained than the isoflavone standards, wesuggest that soybean cake may be a useful potential source for developing effective skincare agents in against photoaging.

Ultrasound-assisted extraction of isoflavones from soy beverages blended with fruit juices

A new method for the fast determination of isoflavones from soy beverages blended with fruit juices without the need of freeze-drying the sample was developed. During the method development, several parameters were studied: solvent (methanol and ethanol), sample:solvent ratio (5:1 to 0.2:1), temperature (10–60 °C) and extraction time (5–30 min). The most important parameter for the extraction of isoflavones from soy drinks was the sample:solvent ratio. The optimized method consists of extracting the sample with ethanol with a sample:solvent ratio of 0.2:1 on an ultrasound bath at 45 °C during 20 min. Also, samples were freeze-dried, extracted using conventional method and compared with the optimized method and no significant difference was observed on total and individual isoflavone concentration. The most representative samples from the Spanish market, with a wide variation of isoflavone concentration were analyzed using the optimized method. Differences between manufacturers reached an almost 10 times fold variation. Overall isoflavone concentration ranged from 6.7 to 58.2 mg L −1.

Continuous hot pressurized fluids extraction of isoflavones and soyasaponins from defatted soybean flakes

This work examined the effect of pressure (413–4410 kPa), temperature (333–393 K), solvent flow rate (10–25 mL/min), ethanol-to-water ratio (0–95%) and the feed loading (80–450 g) on hot pressurized fluids extraction of isoflavones and soyasaponins from defatted soybean flakes. A four-factor Taguchi experimental design was employed to optimize operational conditions of these extractions. Experimental results indicated that 95% of isoflavones and 76% soyasaponins were recovered from defatted soybean flakes by using hot pressurized 80% ethanol extraction at 383 K, 551 kPa and 25 mL/min with a 80 g feed loading. The recovered isoflavones were further purified by a solid–liquid column packed with Amberlite XAD 16-HP resin. The content of isoflavones in the collected fraction could be enhanced from 1 to 58% by weight.

Effects of soy isoflavone supplementation on cognitive function in Chinese postmenopausal women

To investigate whether soy-derived isoflavone extract improves performance in cognitive function and quality of life in Chinese postmenopausal women. The study was a 6-month double-blind, randomized, placebo-controlled, parallel group trial. Participants were community-dwelling women aged 55 to 76 years; 191 eligible women were randomly assigned to receive a daily oral intake of 80 mg soy-derived isoflavones or an identical-appearing placebo for 6 months. Standardized neuropsychological tests of memory, executive function, attention, motor control, language, and visual perception and a global cognitive function assessment were administered face-to-face individually at baseline and at 6-months posttreatment. The validated Chinese version of the Short Form-36 was used for quality of life measurements. Of the participants, 88% (168 women: 80 among the supplementation group and 88 among the placebo group) completed the trial. Intention-to-treat analysis, conducted for 176 participants with 6-month assessment results, revealed no significant differences in outcome measures between treatment groups. Subgroup analysis among the good compliers only (consumed at least 80% of the supplements or placebo; n = 168) and among the age groups younger or older than 65 years also indicated no significant differences for any outcome measures. Types of complaints of adverse events were similar in both treatment groups and included mainly gastrointestinal and musculoskeletal problems. This 6-month trial indicates that 80-mg soy-derived isoflavone supplementation did not improve performance on standard neuropsychological tests and overall quality of life in generally healthy Chinese postmenopausal women.