Blockade of chronic high glucose-induced endothelial apoptosis by Sasa borealis bamboo extract.

Hyperglycemia is a causal factor in the development of diabetic vascular complications including impaired vascular smooth muscle contractility and increased cell proliferation. The present study was designed to investigate the effects of Sasa borealis water-extract (SBwE) on chronic hyperglycemia-induced oxidative stress and apoptosis in human umbilical endothelial cells (HUVEC). HUVEC were cultured in 5.5 mM low glucose, 5.5 mM glucose plus 27.5 mM mannitol as an osmotic control, or 33 mM high glucose for 5 days in the absence and presence of 1-30 microg/ ml SBwE. Caspase-3 activation and Annexin V staining revealed chronic high glucose-induced endothelial apoptotic toxicity with a generation of oxidants detected by DCF-fluorescence, and these effects were reversed by SBwE at > or =1 microg/ml in a dose-dependent manner. Cytoprotective SBwE substantially reduced the sustained high glucose-induced expression of endothelial nitric oxide synthase and attenuated the formation of peroxynitrite radicals. The suppressive effects of SBwE were most likely mediated through blunting activation of PKC beta 2 and NADPH oxidase promoted by high glucose. In addition, this bamboo extract modulated the high glucose-triggered mitogen-activated protein kinase-dependent upregulation of heat-shock proteins. Our results suggest that SBwE suppressed these detrimental effects caused by PKC-dependent peroxynitrite formation via activation of NADPH oxidase and induction of nitric oxide synthase and heat-shock protein family that may be essential mechanisms responsible for increased apoptotic oxidative stress in diabetic vascular complications. Moreover, the blockade of high glucose-elicited heat-shock protein induction appeared to be responsible for SBwE-alleviated endothelial apoptosis. Therefore, SBwE may be a therapeutic agent for the prevention and treatment of diabetic endothelial dysfunction and related complications.

Dietary folate intake, blood folate status, and urinary folate catabolite excretion in Korean women of childbearing age.

This study assessed folate intake, folate concentrations in plasma and erythrocytes, plasma total homocysteine (tHcy) concentrations, and urinary excretion of folate metabolites in Korean women of childbearing age. A total of 36 women voluntarily participated in this study. Precise dietary intake for 3 consecutive days was determined by weighing all foods consumed, and folate intake was calculated with a computer-aided dietary analysis system. Folate concentrations in plasma and erythrocytes were determined via microbiological methods and in plasma by HPLC. Urine excreted over the same period of time was collected and assayed for folate catabolites, para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (ApABG) by reverse-phase HPLC after affinity chromatography. The mean folate intake was 206.9+/-90.8 microg DFE/d, and the mean concentrations in plasma and erythrocytes were 10.5+/-3.7 and 249.9+/-77.8 ng/mL, respectively. Erythrocyte folate concentration was low in 2.8% of the subjects (<140 ng/mL) and was marginal in 5.5% (140-156 ng/mL). The mean plasma tHcy concentration was 12.7+/-0.2 nmol/mL, and 11% of the subjects evidenced hyperhomocysteinemia (>or=15 nmol/mL). The mean urinary excretion levels of pABG and ApABG were 10.7+/-3.8 and 89.1+/-19.5 nmol/d, respectively. The means of folate reserve and folate turnover rate were 26.2+/-11.6 and 10.5+/-3.9, respectively. We noted positive relationships between folate intake and the folate concentrations in plasma and erythrocytes, as well as the urinary excretions of ApABG and total folate catabolites. In addition, the erythrocytic folate concentrations were positively associated with the urinary excretions of ApABG and total folate catabolites. In conclusion, the folate status of Korean women of childbearing age was marginally deficient with inadequate concentrations of erythrocyte folate and elevated plasma tHcy, largely due to insufficient folate intake. The marginally deficient folate status was confirmed by the low excretion of folate catabolites in urine.

Effect of time of initiation and dose of prenatal iron and folic acid supplementation on iron and folate nutriture of Korean women during pregnancy.

BACKGROUND: In Korea, it is customary to prescribe iron and folic acid supplements to pregnant women after the 20th wk of gestation; however, little evidence exists to support this practice. OBJECTIVE: The objective was to determine the effects of time of initiation and dose of prenatal iron and folic acid supplementation on the iron and folate nutriture of Korean women during pregnancy. DESIGN: A total of 131 pregnant women were placed into 1 of 5 experimental groups, either the control group or 1 of 4 supplemented groups. The supplemented groups varied by time of initiation, which was either during the first trimester or at week 20 of gestation, and by dose of iron and folic acid supplements provided, which consisted of either 30 mg Fe plus 175 microg folic acid or 60 mg Fe plus 350 microg folic acid. All supplemented groups continued supplementation until delivery. RESULTS: Improvements in iron and folate nutriture were highly dependent on when the supplement program was initiated, but both supplement doses were equally effective. In contrast, the influence of folic acid supplementation on maternal folate status was not as pronounced as was the influence of iron supplementation on iron status. CONCLUSION: In pregnant Korean women, initiating iron and folic acid supplementation earlier during pregnancy may prevent the deterioration of iron and folate nutriture more than does increasing supplement doses in later stages of pregnancy.

Plasma total homocysteine, folate, and vitamin B12 status in Korean adults.

Elevated plasma total homocysteine (tHcy) levels have been established as a risk factor for occlusive cardiovascular disease. Also known is that plasma folate and vitamin B12 influence homocysteine metabolism as cosubstrate and cofactor, respectively. However, not much information is available describing plasma tHcy levels and their relationship to plasma folate and vitamin B12 status in Koreans. We measured the plasma levels of tHcy, folate, and vitamin B12 in 195 adults (99 males, 96 females; 23-72 y old in the lower middle class). The mean plasma tHcy levels of males, 11.18 +/- 3.88 micromol/L, was significantly higher (p < 0.001) than that of females, 9.20 +/- 2.65 micromol/L. The distribution of tHcy levels of males showed a wide range, 3-50 micromol/L, with a long tail toward higher values. Thus the incidence of hyperhomocysteinemia (> or = 5 micromol/L) in males, 10.1%, was significantly higher (< 0.02) than the 2.1% in females. As age increased, plasma tHcy levels tended to be higher in females. Therefore, sex differences in plasma tHcy levels disappeared in subjects over fifty. On the other hand, both plasma folate (6.47 +/- 3.06 vs 7.96 +/- 3.55 ng/mL, p < 0.01) and vitamin B12 levels (537.0 +/- 222.0 vs. 664.1 +/- 309.8 ng/mL, p < 0.01) were significantly lower in males than in females. A plasma folate deficiency (< 3.0 ng/mL) was found in 6.1% of males and 2.1% of females. And a vitamin B12 deficiency (< 150 pg/mL) was detected in 2.0% and 1.0%, respectively. Plasma tHcy levels were related with inversely plasma concentrations of folate (r = -0.37249, p < 0.001) as well as vitamin B12 (r = -0.22560, p < 0.01) in both sexes. Plasma levels of tHcy and the prevalence of hyperhomocysteinemia in Korean adults are similar to findings in the West. Our results indicate that male adults may be in worse condition for cardiovascular disease (CVD) than females. And improving folate and vitamin B12 status may reduce plasma tHcy level, which may be more important in males.

Sasa borealis leaves extract improves insulin resistance by modulating inflammatory cytokine secretion in high fat diet-induced obese C57/BL6J mice.

Obesity is considered a mild inflammatory state, and the secretion of inflammation-related cytokines rises as adipose tissue expands. Inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), interlukin 6 (IL-6) and monocyte-chemoattractant protein 1 (MCP-1), are modulated by adipose tissue and known to play an important role in insulin resistance which is the common characteristics of obesity related disorders. In this study we analyzed the effects of Sasa borealis leaves extract on inflammatory cytokines and insulin resistance in diet induced obese C57/BL6J mice. The obese state was induced by a high fat diet for 20 weeks and then the mice were divided into two groups; obese control group (OBC, n = 7) and experimental group (OB-SBE, n = 7). The OBC group was fed a high fat diet and the OB-SBE group was fed a high fat diet containing 5% Sasa borealis leaves extract (SBE) for 12 weeks. We also used mice fed a standard diet as a normal control (NC, n = 7). The body weight and adipose tissue weight in the OB group were significantly higher than those in the NC group. The effects of the high fat diet were reduced by SBE treatments, and the body weight and adipose tissue deposition in the OB-SBE group were significantly decreased compared to the OBC group. The OBC group showed higher serum glucose and insulin levels which resulted in a significant increase of incremental area under the curve (IAUC) and HOMA-IR than the NC group. Also, serum leptin, TNF-alpha, and IL-6 levels were significantly higher in the OBC group than in the NC group. In contrast, the OB-SBE group showed a reversal in the metabolic defects, including a decrease in glucose, insulin, IAUC, HOMA-IR, TNF-alpha, IL-6 and leptin levels. These results suggest that BSE can suppress increased weight gain and/or fat deposition induced by a high fat diet and theses effects are accompanied by modulation of the inflammatory cytokines, TNF-alpha and IL-6 secretion resulting in improved insulin resistance.

Childbearing women of twenty and under are at greater risk than those of twenty-five and over for compromised folate status.

This study assessed folate intakes, folate concentrations in plasma and erythrocytes, plasma total homocysteine (tHcy) concentration, and urinary excretion of folate metabolites in Korean women with childbearing potential. A total of 23 women voluntarily participated in this study. Precise dietary intakes for 3 consecutive days were determined by weighing all foods consumed and folate intake was calculated using a computer-aided dietary analysis system. Folate concentration of plasma and erythrocytes was determined by a microbiological method. Plasma tHcy concentration was assayed using an HPLC analysis method. Urine excreted over the same period of time was collected and folate catabolites, para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (ApABG), were evaluated using a reverse-phase HPLC method after affinity chromatography. Young women of 20 and under were likely to consume less folate with low energy intake, had lower folate concentration in plasma and erythrocytes, and excreted a lesser amount of ApABG and total folate catabolites than women of 25 years and over. The results of this study confirmed that young Korean women with childbearing potential, especially those under 21 years of age, might be at risk for compromised folate status due to insufficient folate intakes from inadequate energy consumption.