Retinoids, carotenoids, and tocopherols in breast adipose tissue and serum of benign breast disease and breast cancer patients.

Various retinoic acid (RA) isomers (all-trans, 13-cis, 11-cis, and 9-cis) as well as retinol, carotenoids, and tocopherol concentrations were determined in both serum and breast adipose tissue of 22 benign breast disease patients and 52 breast cancer patients categorized into 4 stages by malignancy. Serum RA isomers were analyzed by a newly developed sensitive method combining a high-performance liquid chromatography and a gas chromatography-mass spectrometry, and retinol, carotenoid, and tocopherol concentrations using a high-performance liquid chromatography system. The breast cancer patients showed significantly lower serum retinol, whereas significantly higher breast adipose tissue retinol concentration than those of benign breast disease patients. Although breast cancer patients showed significantly higher serum all-trans and 13-cis RA concentrations, 11-cis RA in breast adipose tissue was significantly lower in the breast cancer patients than those of benign breast disease patients and it was associated with the stage of malignancy. The current study indicates that the retinol and RA isomers in the target tissue of breast tumor patients are not reflecting their concentrations in circulation. The mechanisms of tissue specific uptake of RA isomers and their functions warrant further studies.

Longitudinal study on trace mineral compositions (selenium, zinc, copper, manganese) in Korean human preterm milk.

We measured selenium, zinc, copper and manganese concentrations in the human milk of Korean mothers who gave birth to preterm infants, and compared these measurements with the recommended daily intakes. The samples of human milk were collected postpartum at week-1, -2, -4, -6, -8, and -12, from 67 mothers who gave birth to preterm infants (< 34 weeks, or birth weight < 1.8 kg). All samples were analyzed using atomic absorption spectrophotometry. The concentrations of selenium were 11.8 ± 0.5, 11.4 ± 0.8, 12.7 ± 0.9, 11.4 ± 0.8, 10.8 ± 0.9, and 10.5 ± 1.3 µg/L, zinc were 7.8 ± 0.5, 9.1 ± 0.8, 7.2 ± 0.9, 8.0 ± 0.8, 7.4 ± 0.9, and 6.6 ± 1.2 mg/L, copper were 506 ± 23.6, 489 ± 29.4, 384 ± 33.6, 356 ± 32.9, 303 ± 35.0, and 301 ± 48.0 µg/L and manganese were 133 ± 4.0, 127 ± 6.0, 125 ± 6.0, 123 ± 6.0, 127 ± 6.0, and 108 ± 9.0 µg/L at week-1, -2, -4, -6, -8, and -12, respectively. The concentrations of selenium and zinc meet the daily requirements but that of copper is low and of manganese exceeds daily requirements recommended by the American Academy of Pediatrics, Committee on Nutrition.

Carotenoids and total phenolic contents in plant foods commonly consumed in Korea.

Phytochemicals are reported to provide various biological functions leading to the promotion of health as well as the reduced risk of chronic diseases. Fat-soluble plant pigments, carotenoids, are extensively studied micronutrient phytochemicals for their potential health benefits. It is noteworthy that specific carotenoids may be responsible for different protective effects against certain diseases. In addition, each carotenoid can be obtained from different types of plant foods. Considering the fact that the phytochemical content in foods can vary according to, but not limited to, the varieties and culture conditions, it is important to establish a database of phytochemicals in locally produced plant foods. Currently, information on individual carotenoid content in plant foods commonly consumed in Korea is lacking. As the first step to support the production and consumption of sustainable local plant foods, carotenoids and total phenolic contents of plant foods commonly consumed in Korea are presented and their potential biological functions are discussed in this review.

Serial changes of fatty acids in preterm breast milk of Korean women.

Samples of breast milk were collected at postpartum weeks 1, 2, 4, 6, 8, and 12 from 104 Korean mothers who had delivered infants at less than 34 weeks or weighing less than 1.8 kg to investigate changes in fatty acid (FAs). Full-term breast milk (FBM) collected at the end of first week postpartum from 26 Korean women delivering healthy, term infants was used for comparison. Stability in relative FA composition was maintained during the first 3 months of lactation in preterm breast milk (PBM), and the relative composition of polyunsaturated FAs (PUFA), monounsaturated FAs, and saturated FAs remained constant in PBM. However, the ω6/ω3 ratio was significantly higher as lactation progressed owing to lower ω3 PUFA in PBM. The proportions of docosahexaenoic acid (DHA) and arachidonic acid (AA) in PBM gradually decreased over time, but the DHA/AA ratio was kept constant at 1.13, higher than that of Western countries. At the end of the first week, relative proportions of FAs were similar in PBM and FBM, but absolute concentrations of FA were higher in PBM.

Effects of retinoic acid isomers on apoptosis and enzymatic antioxidant system in human breast cancer cells.

Retinoic acids (RAs) modulate growth, differentiation, and apoptosis in normal, pre-malignant & malignant cells. In the present study, the effects of RA isomers (all-trans RA, 13-cis RA, and 9-cis RA) on the cell signal transduction of human breast cancer cells have been studied. The relationship between RAs and an enzymatic antioxidant system was also determined. Estrogen-receptor (ER) positive MCF-7 and ER-negative MDA-MB-231 human breast cancer cells were treated with different doses of each RA isomers, all-trans RA, 13-cis RA, or 9-cis RA. Treatment of RA isomers inhibited cell viability and induced apoptosis of MCF-7 cells as a result of increased caspase activity in cytoplasm and cytochrome C released from mitochondria. All-trans RA was the most effective RA isomer in both cell growth inhibition and induction of apoptosis in MCF-7 cells. However, no significant effect of RA isomers was observed on the cell growth or apoptosis in ER-negative MDA-MB-231 cells. In addition, activities of antioxidant enzymes such as catalase and glutathione peroxidase were decreased effectively after treatment of RA in MCF-7 cells, whereas SOD activity was rarely affected. Thus, the present data suggest that all-trans RA is the most potential inducer of apoptosis and modulator of antioxidant enzymes among RA isomers in MCF-7 human breast cancer cells.

A fluorometric assay to determine antioxidant activity of both hydrophilic and lipophilic components in plant foods.

This study aimed to develop a fluorometric method to determine total antioxidant activity of plant foods. The antioxidant activities in plant foods were determined after extracting (1) hydrophilic components with acidified methanol (methanol:glacial acetate acid:water=50:3.7:46.3), (2) lipophilic components with methanol followed by tetrahydrofuran (THF), or (3) both hydrophilic and lipophilic components using sequential extraction of acidified methanol and THF together. Both the hydrophilic assay [using the hydrophilic radical initiator 2,2'-azobis-(2-amidinopropane)dihydrochloride (10 mmol/L) and hydrophilic probe 2,7-dichlorodihydrofluorescein (DCFH)] and the lipophilic assay [using the lipophilic radical initiator [2,2'-azobis (4-methoxiy-2,4-dimethylvaleronitrile), 2 mmol/L], and the lipophilic probe 4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid (C11-BODIPY 581/591) (BODIPY: 2 micromol/L)] were used to measure antioxidant activity. The inhibition of BODIPY oxidation was significantly increased (P<.01) when both the hydrophilic and lipophilic components were extracted using acidified methanol and organic solvent as compared to those extracted by organic solvent alone. In addition, the rate of DCFH oxidation was significantly delayed (P<.05) when both components coexisted compared to DCFH oxidation of the hydrophilic component alone. The combination of lipophilic and hydrophilic components in these plant foods showed significantly greater antioxidant activity than that of either hydrophilic or lipophilic component alone. Thus, both hydrophilic and lipophilic components in plant foods and their interactions should be considered when determining their antioxidant activity.

Kale juice improves coronary artery disease risk factors in hypercholesterolemic men.

OBJECTIVE: To evaluate the effect of 3-month kale (Brassica oleracea acephala) juice supplementation on coronary artery disease risk factors among hypercholesterolemic men. METHODS: Thirty-two men with hypercholesterolemia (> 200 mg/dL) were recruited after annual health examinations among the faculty and staff at university. The subjects consumed 150 mL of kale juice per day for a 12-week intervention period. Dietary and anthropometric assessments were performed and blood samples were collected to evaluate biochemical profiles before and after supplementation. RESULTS: Serum concentrations of HDL-cholesterol, and HDL- to LDL-cholesterol ratio were significantly increased by 27% (P<0.0001) and 52% (P<0.0001), respectively. The LDL-cholesterol concentration and the atherogenic index were significantly reduced by 10% (P=0.0007) and 24.2% (P<0.0001), respectively without affecting body mass index, waist and hip circumferences, or nutrient intakes after three months of supplementation. While there was no difference in the concentration of malondialdehyde, significant increase in glutathione peroxidase activity (P=0.0005) were accompanied by a significant increase in the serum selenium level (P=0.0132). It was also found that the responses of these risk factors to kale juice administration were dependent on smoking status. CONCLUSION: Regular meals supplementation with kale juice can favorably influence serum lipid profiles and antioxidant systems, and hence contribute to reduce the risks of coronary artery disease in male subjects with hyperlipidemia.

Micellar phytosterols effectively reduce cholesterol absorption at low doses.

BACKGROUND: The objective of this study was to evaluate the effects of micellar phytosterols on cholesterol absorption in humans. METHODS: 24 healthy adults (mean age 37 years, 16 women and 8 men) underwent four cholesterol-absorption tests to compare the effects of micellar phytosterols supplement containing 500, 300, 200 mg phytosterols and placebo on cholesterol absorption in a cross-over design. Individual absorption tests were separated by 2 weeks. Using the single oral isotope method, inhibition of cholesterol absorption was determined by gas-chromatography mass spectrometry measurement of the differences in plasma hexadeuterated cholesterol enrichment 4 days after test meals with or without phytosterols. Each test meal provided 500 kcal and 89 mg cholesterol including 40 mg tracer cholesterol. We used a general linear mixed model with SAS to test the significance of treatment effect. RESULTS: Micellar phytosterols had a significant overall effect on cholesterol absorption (p = 0.0002), reduced cholesterol absorption by 23.3% at a dose of 300 mg phytosterols (p = 0.0004) and by 32.0% at a dose of 500 mg phytosterols (p = 0.0001) compared with the placebo. The effect of 200 mg treatment did not reach statistical significance but there was a tendency (p = 0.052). CONCLUSION: Water-dispersible, micellar phytosterols reduced cholesterol absorption effectively at very low doses.

Changes in lipid peroxidation and antioxidant trace elements in serum of women with cervical intraepithelial neoplasia and invasive cancer.

This study investigated serum lipid peroxidation, antioxidant capacity, and trace element levels in Korean women as related to uterine cervical neoplasia. Twenty-eight subjects had cervical intraepithelial neoplasia (CIN), 36 had invasive cervical cancer, as determined by a colposcopically directed biopsy, and controls included 44 subjects with normal colposcopic findings. Significantly lower selenium (Se) and zinc (Zn) levels and higher copper/Zn ratios were found in both CIN and cancer patients compared with the controls. Serum malondialdehyde levels decreased significantly in the order CIN>cancer>control, implying the involvement of reactive oxygen species at the precancerous stage, that is, prior to progression into invasive cervical cancer. Serum glutathione peroxidase activity was significantly lower in patients with CIN or cancer than controls, and total antioxidant ability decreased from controls to CIN to cancer (P < 0.0001). This study demonstrated the involvement of lipid peroxidation, decreased Se and Zn levels, and an impaired serum antioxidant system in the pathogenesis of cervical dysplasia. Further research is needed to examine the possibility of an effective chemopreventive treatment in cervical cancer based on enhancing the endogenous antioxidant system.