Biomedical subjects

Mi-Kyung Sung

Publications and source records attributed to Mi-Kyung Sung.

At least 19 recordsLinked to original sources

PubMed2006

Genes up-regulated during red coloration in UV-B irradiated lettuce leaves.

Molecular analysis of gene expression differences between green and red lettuce leaves was performed using the SSH method. BlastX comparisons of subtractive expressed sequence tags (ESTs) indicated that 7.6% of clones encoded enzymes involved in secondary metabolism. Such clones had a particularly high abundance of flavonoid-metabolism proteins (6.5%). Following SSH, 566 clones were rescreened for differential gene expression using dot-blot hybridization. Of these, 53 were found to overexpressed during red coloration. The up-regulated expression of six genes was confirmed by Northern blot analyses. The expression of chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), and dihydroflavonol 4-reductase (DFR) genes showed a positive correlation with anthocyanin accumulation in UV-B-irradiated lettuce leaves; flavonoid 3',5'-hydroxylase (F3',5'H) and anthocyanidin synthase (ANS) were expressed continuously in both samples. These results indicated that the genes CHS, F3H, and DFR coincided with increases in anthocyanin accumulation during the red coloration of lettuce leaves. This study show a relationship between red coloration and the expression of up-regulated genes in lettuce. The subtractive cDNA library and EST database described in this study represent a valuable resource for further research for secondary metabolism in the vegetable crops.

Acyltransferases↗

PubMed2006

Korean red ginseng (Panax ginseng) improves glucose and insulin regulation in well-controlled, type 2 diabetes: results of a randomized, double-blind, placebo-controlled study of efficacy and safety.

BACKGROUND AND AIM: To address the paucity of randomized clinical studies assessing ginseng on long-term outcomes in type 2 diabetes, we assessed the clinical antidiabetic efficacy and safety of 12 weeks of supplementation with a Korean red ginseng (KRG) preparation, dose, and mode of administration, selected from an acute, clinical, screening model. METHODS AND RESULTS: Nineteen participants with well-controlled type 2 diabetes (sex: 11 M:8 F, age: 64+/-2 years, BMI: 28.9+/-1.4 kg/m(2), HbA(1c): 6.5%) completed the study. Using a double-blind, randomized, crossover design, each participant received the selected KRG preparation (rootlets) and placebo at the selected dose (2 g/meal=6 g/day) and mode of administration (preprandial oral agent [-40 min]) for 12 weeks as an adjunct to their usual anti-diabetic therapy (diet and/or medications). Outcomes included measures of efficacy (HbA1c and fasting- and 75-g oral glucose tolerance test [OGTT]-plasma glucose [PG], plasma insulin [PI], and insulin sensitivity index [ISI] indices); safety (liver, kidney, haemostatic, and blood-pressure function); and compliance (returned capsules, diet-records, and body-weight). There was no change in the primary endpoint, HbA(1c). The participants, however, remained well-controlled (HbA1c=6.5%) throughout. The selected KRG treatment also decreased 75 g-OGTT-PG indices by 8-11% and fasting-PI and 75 g-OGTT-PI indices by 33-38% and increased fasting-ISI (homeostasis model assessment [HOMA]) and 75 g-OGTT-ISI by 33%, compared with placebo (P<0.05). Safety and compliance outcomes remained unchanged. CONCLUSIONS: Although clinical efficacy, as assessed by HbA1c, was not demonstrated, 12 weeks of supplementation with the selected KRG treatment maintained good glycemic control and improved PG and PI regulation safely beyond usual therapy in people with well-controlled type 2 diabetes. Further investigation with similarly selected KRG treatments may yield clinical efficacy.

Administration, Oral↗

PubMed2006

Genistein and daidzein modulate hepatic glucose and lipid regulating enzyme activities in C57BL/KsJ-db/db mice.

This study examines whether anti-diabetic effects of genistein and daidzein are mediated by hepatic glucose and lipid regulating enzyme activities in type 2 diabetic animals. Male C57BL/KsJ-lepr(db)/lepr(db) (db/db) mice and age-matched non-diabetic littermates (db/+) were used in this study. The db/db mice were divided into control, genistein (0.02%, w/w) and daidzein (0.02%, w/w) groups. The blood glucose and HbA(1c) levels were significantly lower in the genistein and daidzein groups than in the control group, while glucose tolerance only was significantly improved in the genistein-supplemented group. The plasma insulin and C-peptide levels did not differ significantly between groups, yet the glucagon level was lower in the genistein and daidzein groups compared to that in the control db/db or db/+ group. The genistein and daidzein supplements increased the insulin/glucagon ratio in the type 2 diabetic animals. While the hepatic glucokinase activity was significantly lower in the db/db control group, the glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities were significantly higher in the control group compared to the db/+ group. Interestingly, these hepatic glucose metabolizing enzyme activities were reversed by the genistein and daidzein supplementation in db/db mice compared to the control group. The hepatic fatty acid synthase, beta-oxidation and carnitine palmitoyltransferase activities were all significantly lower in the genistein and daidzein groups than in the control group. The genistein and daidzein supplements also improved the plasma total cholesterol, triglyceride, HDL-cholesterol/total cholesterol, free fatty acid and hepatic triglyceride concentrations in the db/db mice. These results suggest that genistein and daidzein exert anti-diabetic effect in type 2 diabetic conditions by enhancing the glucose and lipid metabolism.

Animals↗

PubMed2006

Effects of quercetin and beta-carotene supplementation on azoxymethane-induced colon carcinogenesis and inflammatory responses in rats fed with high-fat diet rich in omega-6 fatty acids.

Chronic inflammation in gastrointestinal tract has been suggested as a risk factor for tumor formation. The effect of dietary supplementation of quercetin or beta-carotene on colon carcinogenesis and inflammatory response in rats fed with high-fat diet rich in omega-6 fatty acids was assessed. Animals were exposed to two weekly subcutaneous injections of AOM (azoxymethane) at a single dose of 15 mg/kg body weight. A portion of rats from each group was sacrificed at 8 weeks after the last AOM treatment to determine ACF (aberrant crypt foci) formation. Colonic mucosa expression of iNOS (inducible nitric oxide) and COX-2 (cyclooxygenase-2) protein, and blood PGE2 (prostaglandin E2) level were measured. The remaining groups of animals were sacrificed at 33 weeks after the last AOM treatment to examine colon tumor formation. Rats on high-fat diet developed more aberrant crypt foci (P<0.05) compared with those of rats on regular diet. In the same vein, but in contrast to the effect seen with regular diet, the high-fat diet induced a significant up-regulation of iNOS expression. There was no significant change in the extent of COX-2 expression or in the PGE2 levels. Quercetin or beta-carotene supplementation reduced the number of ACF only in animals fed high-fat diet (p<0.05), however, no significant difference in tumor incidence was found. At week 33, the expression of iNOS was reduced by quercetin without a statistical significance, and COX-2 expression was slightly reduced in rats on beta-carotene supplementation. No change in PGE2 levels was observed. Whilst dietary antioxidants are considered as effective suppressors for precancerous lesion formation in colons exposed to high-risk diet, it is clear that elucidating the role of individual antioxidants in colon tumor formation coupled with an understanding of the molecular mechanisms involved would benefit colon cancer prevention strategies.

Animals↗

PubMed2006

Low molecular proanthocyanidin dietary biofactor Oligonol: Its modulation of oxidative stress, bioefficacy, neuroprotection, food application and chemoprevention potentials.

Interdisciplinary research endeavors are directed at understanding the molecular mechanisms of neurodegenerative and chronic diseases that affect human lifestyle. Hence the potential for developing medicinal herb-derived and food plant-derived prophylactic agents directed at neurological, metabolic, cardiovascular and psychiatric disorders abounds. Oligonol is a novel technology product emanating from the oligomerization of polyphenols, typically proanthocyanidin from a variety of fruits (grapes, apples, persimmons etc.) that has optimized bioavailability. It is an optimized phenolic product containing catechin-type monomers and oligomeric proanthocyanidins, the easily absorbed forms. Typically the constituents of Oligonol are 15-20% monomers, 8-12% dimers and 5-10% trimers. Supplementation of mice with Oligonol prior to the administration of ferric-nitrilotriacetic complex (a Fenton chemistry model) significantly reduced the extent of lipid peroxidation in the kidney, brain and liver. Oligonol triggers apoptosis in the MCF-7 and MDA-MB-231 breast cancer cells through modulation of the pro-apoptotic Bcl-2 family of proteins and the MEK/ERK signaling pathway, an observation suggesting its important chemopreventive effects. The senescence-accelerated strain of mice (SAM) are models of senescence acceleration and geriatric disorders which exhibit learning and memory deficits and enhanced production or defective control of oxidative stress leading.

Animals↗

PubMed2006

Korean red ginseng rootlets decrease acute postprandial glycemia: results from sequential preparation- and dose-finding studies.

BACKGROUND: Fractionation of a ginseng source to produce differences in the ginsenoside profile might influence its effect on postprandial glycemia. To explore this possibility and identify an efficacious ginseng for a longterm study, we conducted a preparation-finding study of different Korean red ginseng (KRG) root fractions followed by a dose-finding study of the most efficacious fraction. METHODS: A double-blind, randomized, within-subject design was used in both studies. In the preparation-finding study, 7 healthy subjects (sex: 3m:4f, age: 32 +/- 4 y, BMI: 24 +/- 2 kg/m2) received 6 g placebo and KRG-rootlets, -body, and -H2O extract 40 min before a 50 g-OGTT with finger-prick blood samples at -40-, 0-, 15-, 30-, 45-, 60-, 90-, 120-min. In the dose-finding study, 12 healthy subjects (sex: 9M,3F, age: 29 +/- 3 y, BMI: 22.5 +/- 1 kg/m2) received 0 g (placebo), 2 g, 4 g, and 6 g of the most efficacious root fraction following the same protocol. Ginsenosides were analyzed using HPLC-UV. RESULTS: In the preparation-finding study, a wide variation in the ginsenoside profiles was achieved across the 3 KRG fractions. This variation coincided with differential effects. The main effects of KRG-rootlets (p = 0.050) and time (p < 0.001) and their interaction (p < 0.1) were significant. This was reflected in a 29% reduction in area under the curve (AUC) by KRG-rootlets compared with placebo (p = 0.052). Conversely, neither KRG-H2O extract nor KRG-body affected glycemia. Stepwise-multiple regression models identified Rg1 as the sole predictor of mean- and AUC postprandial blood glucose. In the dose-finding study, KRG-rootlets were tested as the most efficacious fraction. A significant effect of KRG-rootlets treatment (mean of 3 doses) but not dose was found. The mean of 3 doses decreased AUC by 17% compared with placebo (p = 0.057). CONCLUSIONS: Together the studies indicate 2 g KRG-rootlets is sufficient to achieve reproducible reductions in postprandial glycemia. But the longterm sustainability of KRG selected using this approach remains to be tested.

Adult↗

PubMed2006

Genistein induces glucose-regulated protein 78 in mammary tumor cells.

Preliminary studies have shown that genistein modulates the expression of some heat shock proteins in mammary tumor cells. In this study, we investigated the effect of genistein pretreatment on the expression of glucose-regulated protein 78 (GRP78) in both estrogen receptor-positive (MCF-7) and -negative (MDA-MB-231) cells. Genistein increased the expression of GRP78 in a dose- and time-dependent manner and suppressed glucose uptake in both cell lines. However, induction of GRP78 by genistein appears not to be directly associated with inhibition of glucose uptake. Genistein treatment also made MDA-MB-231 cells more sensitive to doxorubicin, probably via increased GRP78 expression, but had no effect or even decreased drug sensitivity in MCF-7 cells. These results suggest that genistein may be exploited as an enhancer of chemotherapeutic agents in certain types of breast cancer.

Breast Neoplasms↗

PubMed2006

Trans-10,cis-12, not cis-9,trans-11, conjugated linoleic acid inhibits G1-S progression in HT-29 human colon cancer cells.

Commercial preparations of conjugated linoleic acid (CLA) contain both positional and geometric isomers of octadecadienoic acid, with cis-9,trans-11 CLA (c9t11) and trans-10,cis-12 CLA (t10c12) as the principal isomers. We showed previously that CLA reduced the incidence of colon tumors in rats treated with 1,2-dimethylhydrazine. In addition, our previous in vitro studies showed that t10c12 inhibited the growth of HT-29 and Caco-2 human colon cancer cells, whereas c9t11 had no effect on cell growth. In the present study, to examine the effects of the CLA isomers on cell cycle and cell cycle regulatory proteins, we treated HT-29 cells with various concentrations (0-4 micromol/L) of the individual CLA isomers. A DNA flow cytometric analysis revealed that t10c12 induced a G1 arrest, whereas c9t11 had no effect on the cell cycle. Western blot analysis of total cell lysates revealed no alteration in the protein expression of cyclin A, cyclin D, cyclin E, cyclin-dependent kinase (CDK) 2, or CDK4 due to t10c12 treatment. However, t10c12 substantially increased the protein expression and mRNA accumulation of the CDK inhibitor p21(CIP1/WAF1). The t10c12 isomer increased the association of p21(CIP1/WAF1) with CDK2 and proliferating cell nuclear antigen, but decreased the levels of phosphorylated retinoblastoma protein (Rb), with an increase in the levels of hypophosphorylated Rb protein. An in vitro kinase assay using histone H1 as a substrate showed that the activities of CDK2 were significantly decreased by t10c12. These results indicate that t10c12 exerts its growth inhibitory effects in colon cancer cells through the induction of G1 cell cycle arrest. The induction of p21(CIP1/WAF1) may be one of the mechanisms by which t10c12 inhibits cell cycle progression in HT-29 cells.

Cyclin-Dependent Kinase 2↗

PubMed2006

Induction of apoptosis by Cordyceps militaris through activation of caspase-3 in leukemia HL-60 cells.

Cordyceps militaris is a traditional herbal ingredient frequently used for tonic and medicinal purposes in eastern Asia. The hot water extract of its cultivated fruiting bodies demonstrated a potent cytotoxic effect against the proliferation of the human premyelocytic leukemia cell HL-60, with an IC50 of 0.8 mg/ml for a 12-h treatment. It induced the characteristic apoptotic symptoms in the HL-60 cells, including DNA fragmentation and chromatin condensation, occurring within 12-16 h of treatment at a dose of 1 mg/ml. The activation of caspase-3 and the specific proteolytic cleavage of poly (ADP-ribose) polymerase were detected during the course of apoptosis induction. These results indicate that the hot water extract of Cordyceps militaris fruiting bodies inhibited cancer cell proliferation by inducing cell apoptosis through the activation of caspase-3, and that the Cordyceps militaris extract may therefore have therapeutic potential against human leukemia.

Apoptosis↗

PubMed2005

Soybean saponins suppress the release of proinflammatory mediators by LPS-stimulated peritoneal macrophages.

Proinflammatory mediators such as prostaglandins (PGs), nitric oxide (NO), certain inflammatory cytokines and chemokines play a pivotal role in tumor development. The anti-inflammatory properties of naturally occurring phytochemicals are associated with significant reduction in the risk of certain cancers in vitro and in vivo. In the present study, we investigated the effects of soybean saponins on the production of proinflammatory mediators in LPS-stimulated peritoneal macrophages. Soybean saponins significantly inhibited the release of PGE(2), NO, TNFalpha and monocyte chemotactic protein-1 (MCP-1) in a dose-dependent manner. Soybean saponins also down-regulated the expression of COX-2 and iNOS at mRNA/protein levels. Moreover, soybean saponins suppressed NF-kappaB activation by blocking IkappaB-alpha degradation. Our data indicate that soybean saponins exhibit anti-inflammatory properties by suppressing the transcription of inflammatory cytokine genes through the NF-kappaB signaling pathway. The anti-inflammatory properties of soybean saponins may be useful for ameliorating inflammatory diseases as well as suppressing tumor progression.

Animals↗

PubMed2005

Induction of thioredoxin is required for nodule development to reduce reactive oxygen species levels in soybean roots.

Nodules are formed on legume roots as a result of signaling between symbiotic partners and in response to the activities of numerous genes. We cloned fragments of differentially expressed genes in spot-inoculated soybean (Glycine max) roots. Many of the induced clones were similar to known genes related to oxidative stress, such as thioredoxin and beta-carotene hydroxylase. The deduced amino acid sequences of full-length soybean cDNAs for thioredoxin and beta-carotene hydroxylase were similar to those in other species. In situ RNA hybridization revealed that the thioredoxin gene is expressed on the pericycle of 2-d-old nodules and in the infected cells of mature nodules, suggesting that thioredoxin is involved in nodule development. The thioredoxin promoter was found to contain a sequence resembling an antioxidant responsive element. When a thioredoxin mutant of yeast was transformed with the soybean thioredoxin gene it became hydrogen peroxide tolerant. These observations prompted us to measure reactive oxygen species levels. These were decreased by 3- to 5-fold in 7-d-old and 27-d-old nodules, coincident with increases in the expression of thioredoxin and beta-carotene hydroxylase genes. Hydrogen peroxide-producing regions identified with cerium chloride were found in uninoculated roots and 2-d-old nodules, but not in 7-d-old and 27-d-old nodules. RNA interference-mediated repression of the thioredoxin gene severely impaired nodule development. These data indicate that antioxidants such as thioredoxin are essential to lower reactive oxygen species levels during nodule development.

Amino Acid Sequence↗

PubMed2005

Effects of dietary mulberry, Korean red ginseng, and banaba on glucose homeostasis in relation to PPAR-alpha, PPAR-gamma, and LPL mRNA expressions.

Despite lack of scientific evidences to support its therapeutic efficacy, the use of herbal supplements has significantly increased. The purpose of this study was to evaluate the effects of traditional anti-diabetic herbs on the progress of diabetes in db/db mice, a typical non-insulin-dependent model. Five different experimental diets were as follows: control diet, 0.5% mulberry leaf water extract diet, 0.5% Korean red ginseng diet, 0.5% banaba leaf water extract diet, and 0.5% combination diet (mulberry leaf water extract/Korean red ginseng/banaba leaf water extract, 1:1:1). Blood levels of glucose, insulin, HbA1c, and triglyceride were measured every 2 weeks. At 12 weeks of age, animals were sacrificed, and tissue mRNA levels of PPAR-alpha, PPAR-gamma, and LPL were determined. Results indicated that mulberry leaf water extract, Korean red ginseng, banaba leaf water extract, and the combination of above herbs effectively reduced blood glucose, insulin, TG, and percent HbA1c in study animals (p<0.05). We also observed that the increased expressions of liver PPAR-alpha mRNA and adipose tissue PPAR-gamma mRNA in animals fed diets supplemented with test herbs. The expression of liver LPL mRNA was also increased with experimental diets containing herbs. The efficacy was highest in animals fed the combination diet for all of the markers used. These results suggest that mulberry leaf water extract, Korean red ginseng, banaba leaf water extract, and the combination of these herbs fed at the level of 0.5% of the diet significantly increase insulin sensitivity, and improve hyperglycemia possibly through regulating PPAR-mediated lipid metabolism.

Adipose Tissue↗

PubMed2004

Antiproliferative crude soy saponin extract modulates the expression of IkappaBalpha, protein kinase C, and cyclooxygenase-2 in human colon cancer cells.

Frequent consumption of soy and soy-based products is associated with reduced cancer incidence particularly for breast, colon, and prostate cancer. In this study, we examined the effect of crude soy saponin extract on PMA (phorbol 12-myristate 13-acetate)-induced inflammatory responses. Human adenocarcinoma cells (HT-29) were treated with various concentrations of saponin extract for 72 h. Cell growth was measured at 24, 48 and 72 h of incubation, and the PMA-induced expressions of cyclooxygenase-2 (COX-2), protein kinase C (PKC), and IkappaBalpha were determined. The results indicate that crude saponin extract decreased cell growth in a dose- and time-dependent manner. Crude soy saponin extract suppressed the degradation of IkappaBalpha in PMA-stimulated cells, while COX-2 and PKC expressions were significantly down-regulated. These findings support the hypothesis that the soy saponins reduce the risk of colon tumorigenesis possibly by suppressing inflammatory responses.

Blotting, Western↗

PubMed2004

Effects of major dietary antioxidants on inflammatory markers of RAW 264.7 macrophages.

Oxidative stresses are involved in the process of chronic inflammatory diseases. The objective of this study was to evaluate and compare the anti-inflammatory activity of major dietary antioxidants. Murine RAW264.7 macrophages (4 x 10(6) cells) were incubated in DMEM containing 10% FBS supplemented with 5 to 20 microM of alpha-tocopherol, beta-carotene or quercetin for 24 hrs, and then treated with LPS for 16 hrs. The medium was collected to measure TNF-alpha, IL-6, PGE2 and nitrite. Expressions of cyclooxygenase-2(COX-2) and inducible nitric oxide synthase(iNOS) were determined using the harvested cells. Results indicate that TNF-alpha and IL-6 accumulations were significantly reduced by 5 to 20 microM quercetin treatment, and 20 microM of alpha-tocopherol treatment. Nitrite release was significantly reduced by 5 microM quercetin treatment. However, PGE2 accumulation was not affected by any of the antioxidants used. Expressions of COX-2 and iNOS were effectively reduced by 5 microM quercetin treatment. These findings indicate that dietary antioxidants possess significant anti-inflammatory activities, and quercetin is the most potent antioxidant.

Analysis of Variance↗

PubMed2003

Effects of phenol-depleted and phenol-rich diets on blood markers of oxidative stress, and urinary excretion of quercetin and kaempferol in healthy volunteers.

OBJECTIVE: Epidemiological studies have suggested beneficial effects of dietary polyphenols in reducing the risk of chronic diseases. This study was performed to investigate the effects of polyphenol-depleted and polyphenol-rich diets on blood oxidative stress markers and urinary excretions of major phenols. METHODS: Nineteen healthy female non-smokers 19 to 21 years of age took part in the study, which consisted of two dietary intervention periods separated by three days. Experimental diets were composed of common foods selected to comply with low contents of polyphenols for phenol-depleted intervention and high contents of polyphenols for phenol-rich diets. Blood and urine samples were collected on day 0, 3 and 6 of each intervention. Duplicate portions of foods provided to the subjects were also collected. Blood oxidative stress markers included plasma antioxidant vitamins, erythrocyte superoxide dismutase (SOD) activity and lymphocyte DNA damage. Urinary excretions of major phenols were measured to affirm bioavailability of dietary phenols. RESULTS: Plasma alpha-tocopherol and beta-carotene concentrations were slightly decreased on day 3 and 6 of the phenol-depleted dietary intervention period, although no change was observed with phenol-rich diets. The erythrocyte SOD activity was also slightly decreased during phenol-depleted dietary intervention. However, at day 6 of the phenol-rich intervention, the activity of SOD was significantly increased by 41%. Tail moment and tail length of lymphocyte DNA as markers of DNA damage were higher on day 6 of phenol-depleted intervention, although only tail moment showed a statistical significance. The average intakes of quercetin and kaempferol during the phenol-rich intervention were 21 mg/day and 9 mg/day, respectively. The average urinary excretion rates during phenol-rich intervention were 2.06% for quercetin and 0.46% for kaempferol. There were positive correlations between erythrocyte SOD activity and urinary concentration of quercetin or kaempferol. CONCLUSIONS: These results suggest that polyphenol-rich diets may decrease the risk of chronic diseases by reducing oxidative stress.

Adult↗

PubMed2003

Inadequate antioxidant nutrient intake and altered plasma antioxidant status of rheumatoid arthritis patients.

OBJECTIVE: Elevated free radical generation in inflamed joints and impaired antioxidant system have been implicated in rheumatoid arthritis (RA). The present study was performed to evaluate dietary nutrient intake and plasma oxidant/antioxidant status in RA patients. METHODS: RA patients (n = 97) and their age, gender-matched controls (n = 97) participated in this cross-sectional case-control study. Nutrient intake was estimated using a semi-quantitative food frequency questionnaire. Twenty subjects from each group provided blood samples, and plasma concentrations of alpha-tocopherol and malondiadehyde (MDA) were measured. Also, plasma activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured. RESULTS: The mean calorie intake of RA patients was lower than that of the healthy controls. Energy-adjusted intake of fat, vitamin A and beta-carotene were significantly lower in patients than those of the control subjects. RA patients had a decreased mean plasma alpha-tocopherol level. The activity of plasma SOD and GPx in patients was significantly lower than that in control subjects. CONCLUSION: These results suggest proper antioxidant nutrient intake management may reduce free radical generation and improve antioxidant status in RA patients.

Antioxidants↗

PubMed2003

Anticarcinogenic properties of a daidzein-rich fraction isolated from soybean.

In a previous study, we demonstrated that the methanol extract of soybean powder contains an active component(s) that promotes the differentiation of HL-60 cells. Partial purification of the extract, using solvent fractionation and silica gel chromatography, produced an active fraction rich in daidzein. The daidzein-rich fraction (DRF) was evaluated for its cancer preventive potential by assessing its cytotoxic activity and effect on the expression of the transforming growth factor beta (TGF-beta) family of cytokines and their receptors. DRF appeared to exert cytotoxic activity via an apoptotic pathway as evaluated by a DNA fragmentation assay and caspase-3 induction. DRF also increased the expression of TGF-beta2, but had little effect on the expression of other members of the TGF-beta family of cytokines and their receptors, or on the expression of the vascular endothelial growth factor gene. In conclusion, the DRF isolated from the methanol extract of soybean may have the potential to prevent tumorigenesis and, therefore, deserves to undergo further evaluation of its active component(s) and in vivo evaluation for anticarcinogenic efficacy.

Animals↗

PubMed2002

Impaired antioxidant status and decreased dietary intake of antioxidants in patients with systemic lupus erythematosus.

OBJECTIVE: This study compared plasma antioxidant/oxidant status and the dietary nutrient intake of patients with systemic lupus erythematosus (SLE) to those of healthy controls. PATIENTS AND METHODS: The study included 97 consecutive patients with SLE and 97 age- and sex-matched healthy controls. Blood samples from 19 patients and 19 controls were subjected to analyses of plasma concentrations of alpha-tocopherol and malone dialdehyde and the activities of superoxide dismutase and glutathione peroxidase in the plasma. All patients and controls were interviewed using a semiquantitative food-frequency questionnaire. RESULTS: The plasma alpha-tocopherol concentration was lower in patients, but this difference was not statistically significant. Plasma superoxide dismutase and glutathione peroxidase activities were significantly lower in patients than in controls, and the plasma malone dialdehyde level was significantly higher in patients than in controls. The intake of all major dietary antioxidants, including vitamin A, beta-carotene, and vitamin C, but not retinol, was lower in patients than in controls, but this difference was significant only for vitamin A and beta-carotene. CONCLUSIONS: These results show that plasma antioxidant status is impaired and dietary antioxidant intake is decreased in patients with SLE.

Adult↗