We investigated the effects of dietary folate supplementation on plasma homocysteine, vitamin B12 and hepatic levels of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) in diet-induced hyperhomocysteinemic rats. All animals were fed 0.3% homocysteine diet for 2 weeks, then they were placed either on a 0.3% homocystine or no homocystine with or without 8 mg/kg folate diet for 8 weeks. Homocystine diet induced hyperhomocysteinemia up to 3.5-fold at 10 weeks (28.0+/-4.8 micromol/l vs. 7.9+/-0.3 micromol/l). Dietary folate supplementation caused a significant decrease in plasma homocysteine levels which had been increased by a homocystine-diet. Also, dietary folate supplementation made them return to control levels at 4 wk when the diet was free of homocystine. Plasma folate levels were markedly decreased with homocystine diet with no folate supplementation. Plasma vitamin B12 did not differ between groups. Dietary homocystine increased hepatic levels of SAM in folate supplementation group at 10 weeks (p<0.05). Dietary folate supplementation increased hepatic levels of SAM/SAH ratios in homocystine group (p<0.05). In conclusion, dietary folate supplementation can effectively ameliorate the detrimental effects of hyperhomocysteinemia.mia.
Animals ; Diet ; Folic Acid* ; Homocysteine ; Homocystine* ; Hyperhomocysteinemia* ; Metabolism* ; Plasma ; Rats* ; S-Adenosylhomocysteine ; S-Adenosylmethionine* ; Vitamin B 12

OBJECTIVETo establish a quantitative analysis method for analyzing the nucleosides in Cordyceps sinensis with capillary electrophoresis, and compare the difference between natural and the cultured C. mycelia.

METHODCapillary zone electrophoresis method was employed to quantitate the adenosine, uridine, guanosine and inosine in C. sinensis, with 0.25 mg x L(-1) boric acid-sodium hydroxide buffer, pH 9.5. The working voltage was 20 kV, the temperature was 25 degrees C, and the detection wavelength was 260 nm.

RESULTWith the capillary zone electrophoresis method, the average recovery of the above 4 nucleosides was 98.9%, 95.1%, 97.8% and 98.8% respectively, with the RSD 0.4%, 1.7%, 1.3% and 5.0%. There was no adenosine in natural C. sinensis and no inosine in the cultured C. mycelia detected.

CONCLUSIONThis method can be used to determine the adenosine, uridine, guanosine and inosine in C. sinensis. The nucleosides in C. sinensis produced from Qinghai province and cultured C. mycelia are obviously different.

Adenosine ; analysis ; Animals ; Cordyceps ; chemistry ; classification ; Culture Techniques ; Electrophoresis, Capillary ; methods ; Guanosine ; analysis ; Inosine ; analysis ; Lepidoptera ; chemistry ; Uridine ; analysis

In rat kidney, the changes in concentrations of nucleotides and their derivatives during ischemia induced by renal artery ligation was measured quantitatively with high performance liquid chromatography (HPLC). After the ligation of renal artery for 60minutes, the concentrations of the nucleotides and derivatives to 80.7±18.39 µg (p<0.01); ATP, 307.2±56.68 µg to 47.6±5.95µg (p<0.01); ADP+AMP, 227.1±7.98 µg to 61.4±3.92 µg (P<0.01); NAD+, 217.9±4.49 µg to 126.6±10.44 µg (P<0.01); GTP, 202.5±23.76 µg to 117.7±14.24 µg (P<0.05); GMP, 54.5±9.03µg to 23.7±0.46 µg (p<0.05), and inosine, 16.6±3.45 µg to 7.8±0.87 µg (P<0.05). But hypoxanthine and xanthine were significantly increased from 113.0±15.58µg to 159.7±12.97µg (P<0.05) and from 87.7±6.77µg to 173.1±12.52µg (P<0.01). In ischemic kidney, concentration of ATP was decreased to 39.9% of control at 10 minutes, 19.8% at 30 minutes, and 15.5% at 60 minutes, and ADP+AMP were decreased to 70.3% of control at 10 minutes, 67.3% at 30 minutes, and to 27.0% at 60 minutes, but hypoxanthine and xanthine were increased to 121.5% and 127.1% at 10 minutes, 126.0% and 174.4% at 30 minutes, and 141.4% and 197.3% at 60 minutes. Total adenosine nucleotides were decreased to 20.3% of control during 60 minutes of ischemia, but hypoxanthine and xanthine were increased to 157.5% of control. These results suggest that the changes in the concentration of nucleotides and their metabolic derivatives are useful indices of the extents of tissue ischemia in rat kidney.
Adenosine ; Adenosine Triphosphate ; Animals ; Chromatography, High Pressure Liquid* ; Chromatography, Liquid ; Guanosine Triphosphate ; Hypoxanthine ; Inosine ; Ischemia* ; Kidney ; Ligation ; Nucleotides* ; Rats* ; Renal Artery ; Xanthine

Folate is generally considered as a safe water-soluble vitamin for supplementation. However, we do not have enough information to confirm the potential effects and safety of folate supplementation and the interaction with vitamin B12 deficiency. It has been hypothesized that a greater methyl group supply could lead to compensation for vitamin B12 deficiency. On this basis, the present study was conducted to examine the effects of high-dose folic acid (FA) supplementation on biomarkers involved in the methionine cycle in vitamin B12-deficient rats. Sprague-Dawley rats were fed diets containing either 0 or 100 microg (daily dietary requirement) vitamin B12/kg diet with either 2 mg (daily dietary requirement) or 100 mg FA/kg diet for six weeks. Vitamin B12-deficiency resulted in increased plasma homocysteine (p<0.01), which was normalized by dietary supplementation of high-dose FA (p<0.01). However, FA supplementation and vitamin B12 deficiency did not alter hepatic and brain S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) concentrations and hepatic DNA methylation. These results indicated that supplementation of high-dose FA improved homocysteinemia in vitamin B12-deficiency but did not change SAM and SAH, the main biomarkers of methylating reaction.
Animals ; Biomarkers ; Brain ; Compensation and Redress ; Diet ; Dietary Supplements ; DNA Methylation ; Folic Acid ; Homocysteine ; Hyperhomocysteinemia ; Methionine ; Plasma ; Rats ; Rats, Sprague-Dawley ; S-Adenosylhomocysteine ; S-Adenosylmethionine ; Vitamin B 12 Deficiency ; Vitamins

BACKGROUND/OBJECTIVE: The aim of this study was to examine the effect of high dietary methionine (Met) consumption on plasma and hepatic oxidative stress and dyslipidemia in chronic ethanol fed rats. MATERIALS/METHODS: Male Wistar rats were fed control or ethanol-containing liquid diets supplemented without (E group) or with DL-Met at 0.6% (EM1 group) or 0.8% (EM2 group) for five weeks. Plasma aminothiols, lipids, malondialdehyde (MDA), alanine aminotransferase (ALT), and aspartate aminotransferase were measured. Hepatic folate, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) were measured. RESULTS: DL-Met supplementation was found to increase plasma levels of homocysteine (Hcy), triglyceride (TG), total cholesterol (TC), and MDA compared to rats fed ethanol alone and decrease plasma ALT. However, DL-Met supplementation did not significantly change plasma levels of HDL-cholesterol, cysteine, cysteinylglycine, and glutathione. In addition, DL-Met supplementation increased hepatic levels of folate, SAM, SAH, and SAM:SAH ratio. Our data showed that DL-Met supplementation can increase plasma oxidative stress and atherogenic effects by elevating plasma Hcy, TG, and TC in ethanol-fed rats. CONCLUSION: The present results demonstrate that Met supplementation increases plasma oxidative stress and atherogenic effects by inducing dyslipidemia and hyperhomocysteinemia in ethanol-fed rats.
Alanine Transaminase ; Animals ; Aspartate Aminotransferases ; Cholesterol ; Cysteine ; Diet ; Dyslipidemias* ; Ethanol ; Folic Acid ; Glutathione ; Homocysteine ; Humans ; Hyperhomocysteinemia ; Male ; Malondialdehyde ; Methionine* ; Oxidative Stress* ; Plasma ; Rats* ; Rats, Wistar ; S-Adenosylhomocysteine ; S-Adenosylmethionine ; Triglycerides

BACKGROUND/OBJECTIVE: The aim of this study was to examine the effect of high dietary methionine (Met) consumption on plasma and hepatic oxidative stress and dyslipidemia in chronic ethanol fed rats. MATERIALS/METHODS: Male Wistar rats were fed control or ethanol-containing liquid diets supplemented without (E group) or with DL-Met at 0.6% (EM1 group) or 0.8% (EM2 group) for five weeks. Plasma aminothiols, lipids, malondialdehyde (MDA), alanine aminotransferase (ALT), and aspartate aminotransferase were measured. Hepatic folate, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) were measured. RESULTS: DL-Met supplementation was found to increase plasma levels of homocysteine (Hcy), triglyceride (TG), total cholesterol (TC), and MDA compared to rats fed ethanol alone and decrease plasma ALT. However, DL-Met supplementation did not significantly change plasma levels of HDL-cholesterol, cysteine, cysteinylglycine, and glutathione. In addition, DL-Met supplementation increased hepatic levels of folate, SAM, SAH, and SAM:SAH ratio. Our data showed that DL-Met supplementation can increase plasma oxidative stress and atherogenic effects by elevating plasma Hcy, TG, and TC in ethanol-fed rats. CONCLUSION: The present results demonstrate that Met supplementation increases plasma oxidative stress and atherogenic effects by inducing dyslipidemia and hyperhomocysteinemia in ethanol-fed rats.
Alanine Transaminase ; Animals ; Aspartate Aminotransferases ; Cholesterol ; Cysteine ; Diet ; Dyslipidemias* ; Ethanol ; Folic Acid ; Glutathione ; Homocysteine ; Humans ; Hyperhomocysteinemia ; Male ; Malondialdehyde ; Methionine* ; Oxidative Stress* ; Plasma ; Rats* ; Rats, Wistar ; S-Adenosylhomocysteine ; S-Adenosylmethionine ; Triglycerides

Folate and vitamin B12 are essential cofactors for homocysteine (Hcy) metabolism. Homocysteinemia has been related with cardiovascular and neurodegenerative disease. We examined the effect of folate and/or vitamin B12 deficiency on biomarkers of one carbon metabolism in blood, liver and brain, and analyzed the correlation between vitamin biomarkers in mild and moderate homocysteinemia. In this study, Sprague-Dawley male rats (5 groups, n = 10) were fed folate-sufficient diet (FS), folate-deficient diet (FD) with 0 or 3 g homocystine (FSH and FDH), and folate-/vitamin B12-deficient diet with 3 g homocystine (FDHCD) for 8 weeks. The FDH diet induced mild homocysteinemia (plasma Hcy 17.41 +/- 1.94 nmol/mL) and the FDHCD diet induced moderate homocysteinemia (plasma Hcy 44.13 +/- 2.65 nmol/mL), respectively. Although liver and brain folate levels were significantly lower compared with those values of rats fed FS or FSH (p < 0.001, p < 0.01 respectively), there were no significant differences in folate levels in liver and brain among the rats fed FD, FDH and FDHCD diet. However, rats fed FDHCD showed higher plasma folate levels (126.5 +/- 9.6 nmol/L) compared with rats fed FD and FDH (21.1 +/- 1.4 nmol/L, 22.0 +/- 2.2 nmol/L)(p < 0.001), which is the feature of "ethyl-folate trap"by vitamin B12 deficiency. Plasma Hcy was correlated with hepatic folate (r = -0.641, p < 0.01) but not with plasma folate or brain folate in this experimental condition. However, as we eliminated FDHCD group during correlation test, plasma Hcy was correlated with plasma folate (r = -0.581, p < 0.01), hepatic folate (r = -0.684, p < 0.01) and brain folate (r = -0.321, p < 0.05). Hepatic S-adenosylmethionine (SAM) level was lower in rats fed FD, FDH and FDHCD than in rats fed FS and FSH (p < 0.001, p < 0.001 respectively) and hepatic S-adenosylhomocysteine (SAH) level was significantly higher in those groups. The SAH level in brain was also significantly increased in rats fed FDHCD (p < 0.05). However, brain SAM level was not affected by folate and/or vitamin B12 deficiency. This result suggests that dietary folate- and vitamin B12-deficiency may inhibit methylation in brain by increasing SAH rather than decreasing SAM level, which may be closely associated with impaired cognitive function in nutritional homocysteinemia.
Animals ; Biomarkers ; Brain ; Carbon ; Diet ; DNA Methylation ; Folic Acid ; Homocysteine ; Homocystine ; Humans ; Hyperhomocysteinemia ; Liver ; Male ; Methylation ; Neurodegenerative Diseases ; Plasma ; Rats ; S-Adenosylhomocysteine ; S-Adenosylmethionine ; Vitamin B 12 ; Vitamin B 12 Deficiency ; Vitamins

Alterations in sulfur amino acid metabolism are associated with an increased risk of a number of common late-life diseases, which raises the possibility that metabolism of sulfur amino acids may change with age. The present study was conducted to understand the age-related changes in hepatic metabolism of sulfur amino acids in 2-, 6-, 18- and 30-month-old male C57BL/6 mice. For this purpose, metabolite profiling of sulfur amino acids from methionine to taurine or glutathione (GSH) was performed. The levels of sulfur amino acids and their metabolites were not significantly different among 2-, 6- and 18-month-old mice, except for plasma GSH and hepatic homocysteine. Plasma total GSH and hepatic total homocysteine levels were significantly higher in 2-month-old mice than those in the other age groups. In contrast, 30-month-old mice exhibited increased hepatic methionine and cysteine, compared with all other groups, but decreased hepatic S-adenosylmethionine (SAM), S-adenosylhomocysteine and homocysteine, relative to 2-month-old mice. No differences in hepatic reduced GSH, GSH disulfide, or taurine were observed. The hepatic changes in homocysteine and cysteine may be attributed to upregulation of cystathionine β-synthase and down-regulation of γ-glutamylcysteine ligase in the aged mice. The elevation of hepatic cysteine levels may be involved in the maintenance of hepatic GSH levels. The opposite changes of methionine and SAM suggest that the regulatory role of SAM in hepatic sulfur amino acid metabolism may be impaired in 30-month-old mice.
Aging ; Amino Acids, Sulfur ; Animals ; Child, Preschool ; Cystathionine ; Cysteine ; Down-Regulation ; Glutathione ; Homocysteine ; Humans ; Infant ; Male* ; Metabolism* ; Metabolomics ; Methionine ; Mice* ; Plasma ; S-Adenosylhomocysteine ; S-Adenosylmethionine ; Sulfur* ; Taurine ; Up-Regulation

Elevated plasma homocysteine ( Hcy) is a risk factor for cognitive dysfunction and Alzheimer disease, although the mechanism is still unknown. Both folate and betaine, a choline metabolite, play essential roles in the remethylation of Hcy to methionine. Choline deficiency may be associated with low folate status and high plasma Hcy. Alterations in DNA methylation also have established critical roles for methylation in development of the nervous system. This study was un-dertaken to assess the effect of choline and folate deficiency on Hcy metabolism and genomic DNA methylation status of the liver and brain. Groups of adult male Sprague Dawley rats were fed on a control, choline-deficient ( CD) , folate-deficient ( FD) or choline/folate-deficient ( CFD) diets for 8 weeks. FD resulted in a significantly lower hepatic folate ( 23%)(p < 0.001) and brain folate ( 69%)(p < 0.05) compared to the control group. However, plasma and brain folate remained unaltered by CD and hepatic folate reduced to 85% of the control by CD ( p < 0.05) . Plasma Hcy was signi-ficantly increased by FD ( 18.34 +/- 1.62 micrometer) and CFD ( 19.35 +/-3.62 micrometer) compared to the control ( 6.29 +/-0.60 micrometer) ( p < 0.001) , but remained unaltered by CD. FD depressed S-adenosylmethionine ( SAM) by 59% ( p < 0.001) and ele-vated S-adenosylhomocysteine ( SAH) by 47% in liver compared to the control group ( p < 0.001) . In contrast, brain SAM levels remained unaltered in CD, FD and CFD rats. Genomic DNA methylation status was reduced by FD in liver ( p< 0.05) . Genomic DNA hypomethylation was also observed in brain by CD, FD and CFD although it was not signifi-cantly different from the control group. Genomic DNA methylation status was correlated with folate stores in liver ( r = - 0.397, p < 0.05) and brain ( r = - 0.390, p < 0.05) , respectively. In conclusion, our data demonstrated that genomic DNA methylation and SAM level were reduced by folate deficiency in liver, but not in brain, and correlated with folate concentration in the tissue. The fact that folate deficiency had differential effects on SAM, SAH and genomic DNA methylation in liver and brain suggests that the Hcy metabolism and DNA methylation are regulated in tissue-specific ways.
Adult ; Alzheimer Disease ; Animals ; Betaine ; Brain ; Choline ; Choline Deficiency ; Diet ; DNA Methylation* ; DNA* ; Folic Acid ; Homocysteine* ; Humans ; Liver ; Male ; Metabolism ; Methionine ; Methylation ; Nervous System ; Plasma* ; Rats* ; Rats, Sprague-Dawley ; Risk Factors ; S-Adenosylhomocysteine ; S-Adenosylmethionine

PURPOSE: Mycophenolic acid (MPA), a selective inhibitor of inosine monophosphate dehydrogenase (IMPDH), is the active metabolite of the immunosuppressive drug, mycophenolate mofetil (MMF). MMF is used to prevent an immune- mediate rejection response following organ transplantation via the inhibition of the IMPDH and GTP biosynthesis pathway. This study was designed to elucidate the mechanism by which MPA exerts its cytotoxic effect on human T lymphocytic and monocytic cell lines. METHODS: MOLT-4 and U937 cell lines were treated with MPA. Cell viability, expression of Bcl2 family proteins and Fas/Fas-L, effects of antioxidants and intracellular Ca2+ regulating agents and apoptosis were measured using a variety of microscopic and biochemical techniques. RESULTS: MPA induced the death of U937 and MOLT-4 cells in dose and time dependent manners, which was revealed an apoptosis with a characteristic ladder pattern of DNA fragmentation. In addition, BAPTA/AM, an intracellular Ca2+ chelator protected MOLT-4 cells from MPA treated apoptosis, although it did not have an additive with thapsigargin, and increases cytosolic Ca2+ stores. However, antioxidants including reduced glutathione (GSH) and N-acetyl-L-cysteine (NAC) did not inhibit the apoptosis of cells by MPA. Furthermore, guanosine suppressed MPA induced apoptosis of MOLT-4 lymphocytes, although adenosine did not. MPA also increased the catalytic activity of caspase family cysteine proteases including caspase-8, 9 and 3 proteases in MOLT-4 cells. Sequential activation indicated that the cleavage of caspase-8 and 9 precedes those of caspase-3. CONCLUSION: The results suggest that MPA induces the apoptotic death of MOLT-4 lymphocytes via the activations of caspase family proteases and the depletion of GTP.
Acetylcysteine ; Adenosine ; Antioxidants ; Apoptosis ; Caspase 3 ; Caspase 8 ; Cell Line ; Cell Survival ; Cysteine Proteases ; Cytosol ; DNA Fragmentation ; Glutathione ; Guanosine ; Guanosine Triphosphate ; Humans ; Inosine Monophosphate ; Lymphocytes ; Mycophenolic Acid* ; Organ Transplantation ; Oxidoreductases ; Peptide Hydrolases ; Signal Transduction* ; T-Lymphocytes* ; Thapsigargin ; Transplants ; U937 Cells