The effect of bioactive complex of quercetin, selenium, catechins and curcumin on cardiovascular risk markers in healthy population after a two month consumption.

BACKGROUND: Nutrition is an important factor in prevention of degenerative age-related diseases. Health benefits of the functional food - cereal selenized onion biscuits with bioactive complex such as selenium in organic form, quercetin (onion), curcumin (curcuma) and catechins (green tea) were evaluated. METHODS: In a group of randomly selected 50 apparently healthy men, aged 30-50 years, the levels of total cholesterol, HDL-cholesterol, C-reactive protein (hs-CRP), homocysteine (HCy) and its nutritional determinants (methionine, vitamin B12, folic acid, cysteine, vitamin B6) and asymmetric dimethylarginine (ADMA) were measured and the LDL cholesterol and atherogenic index was calculated before and after a 2-month consumption period and after a 2-month wash-out period. RESULTS: The significant reduction of total cholesterol, LDL-cholesterol, atherogenic index, HCy and ADMA was found after onion biscuit consumption. Alternative pathway for HCy degradation using betaine as methyl donor is probably a sole argument for reduced HCy value at the significantly reduced concentrations of the methionine, folic acid, cysteine and vitamin B6. Value of hs-CRP was non-significantly reduced after biscuit consumption. CONCLUSION: The results of improved lipid profile, significantly reduced values of HCy and ADMA document a beneficial effect of cereal biscuit with selenized onion, curcuma and green tea in prevention of cardiovascular disease (Tab. 2, Ref. 19).

Selected biomarkers of age-related diseases in older subjects with different nutrition.

BACKGROUND: The nutritionists introduce on the base of epidemiological and clinical studies that appropriately planned vegetarian diets are healthful, and may provide health benefits in the prevention and treatment of certain diseases. Aging belongs to the main risks of cardiovascular disease. METHODS: Markers of age-related diseases (cardiovascular, metabolic syndrome, diabetes) were assessed in two nutritional groups of older apparently healthy non-obese non-smoking women aged 60-70 years, 45 vegetarians (lacto-ovo-vegetarians and semi-vegetarians) and 38 non-vegetarians (control group on a traditional mixed diet, general population). RESULTS: Vegetarian values of total cholesterol, LDL-cholesterol, triacylglycerols, C-reactive protein, glucose, insulin and insulin resistance are significantly reduced. Non-vegetarian average values of total cholesterol, LDL-cholesterol and C-reactive protein are risk. Vegetarians have a better antioxidative status (significantly increased vitamin C, lipid-standardized vitamine E and beta-carotene plasma concentrations). CONCLUSION: Favourable values of cardiovascular risk markers in older vegetarian women document a beneficial effect of vegetarian nutrition in prevention of this disease as well as the vegetarian diet can be an additional factor in therapy. Vegetarians suffer from mild hyperhomocysteinemia; it is due to the lower vitamin B12 concentration. Vitamin B12 supplements are inevitable for the hyperhomocysteinemia prevention (Tab. 2, Ref. 26).

Placental markers of folate-related metabolism in preeclampsia.

The etiology and degree of clinical symptoms of preeclampsia depend on genotypic and phenotypic maternal and trophoblast factors, and elevated levels of plasma homocysteine (Hcy) are one of the pathogenetic factors of preeclampsia. To assess the impact of the folate-related metabolism, we characterized the indices of this metabolism in 40 samples from uncomplicated term placentas and 28 samples from preeclamptic pregnancies by quantifying the total content of folate, methionine (Met), Hcy and related cysteine, and glutathione (GSH) in compliance with the 677 C/T genotype of methylene tetrahydrofolate reductase (MTHFR). The prevalence of MTHFR genotypes was not significantly different between the two groups. The polymorphism of MTHFR was not unambiguously connected with the content of total placental Met, Hcy and related cysteine, and GSH either in uncomplicated or in complicated pregnancies. By contrast, the combination of the heterozygous MTHFR genotype with folate deficiency in the samples from preeclamptic pregnancies was characterized by a statistically significant decrease in the Met content, a trend toward increased Hcy levels and a tight association between metabolically directly and indirectly related compounds, e.g. positive relation between Hcy versus cysteine and folate versus GSH and negative relation between folate versus Hcy and both Hcy and cysteine versus GSH. We demonstrated the expression of cystathionine-ß-synthase (CBS) in human placenta at term by RT-PCR and western blot analysis, for the first time, and confirmed its catalytic activity and the accumulation of cysteine and CBS in placental explants cultivated in the presence of elevated Hcy concentrations. We suggest that disturbance in placental folate-related metabolism may be one of the pathogenetic factors in preeclampsia.

Hypercholesterolemia, oxidative stress and gender dependence in children.

Hypercholesterolemia (HCH) is characterized by an increase of the total- and LDL-cholesterol in serum. In hypercholesterolemia, generally recognized as a risk factor of atherogenesis, oxidative stress and oxidatively modified LDL play a crucial role. In our study, children with elevated total cholesterol (above 4.5 mmol/l) were included. Parameters of lipid profile, lipophilic vitamins and antioxidants (retinol, α-tocopherol, γ-tocopherol, xantophyll, lycophen and ß-carotene) and markers of oxidative damage to lipids (lipoperoxides and 8-isoprostanes) were evaluated. We found that children with hypercholesterolemia have significantly increased parameters of lipid profile and these are gender dependent only in HDL-cholesterol (1.27 ± 0.10 mmol/l in boys vs. 1.53 ± 0.07 mmol/l in girls; p<0.05) and TAG (1.63 ± 0.31 mmol/l in boys vs. 1.08 ± 0.09 mmol/l in girls; p<0.05). In addition, children with HCH have decreased total antioxidant capacity of serum (TEAC) (about 19.64%, p<0.05) and increased lipoperoxides (LP) (about 45.73%, p<0.001). We have revealed statistically significant correlations between parameters of lipid profile and lipophilic vitamins and antioxidants, as well as between markers of oxidative stress: positive correlation between LP and 8-iso (r=0.353, n=33, p<0.05) and negative correlations between these parameters and TEAC (r= -0.377, n=33, p<0.05 for LP and r= -0.379, n=33, p<0.05 for 8-iso). In conclusion, we confirmed relation between hypercholesterolemia and oxidative stress and effect of gender on these processes already in childhood. Since the atherosclerotic process begins in childhood before clinical symptoms, early detection of hypercholesterolemia and oxidative stress is important in later atherosclerosis prevention.

Plasma concentrations of selected antioxidants in autistic children and adolescents.

Few studies have demonstrated an increased vulnerability to oxidative stress in autism. The results of previous studies have shown that endogenous antioxidant defence is insufficient, indicating that exogenous antioxidant could play a crucial role for oxidative stress prevention in autism. Plasma concentrations of vitamins C, E, A, carotenoids beta-carotene and lycopene were measured in 51 subjects with autistic spectrum disorders aged 5-18 years (27 children aged 5-10 years, 24 subjects aged 11-18 years). Older autistic group was compared with a group of healthy Slovak subjects aged 11-18 years. Older autistic subjects vs. healthy control showed significantly higher vitamin C and beta-carotene plasma values with 92% and 71% vs 54% and 13% of optimal over-threshold values, respectively. This indicates a reduced risk of free radical disease. In younger vs. older autistic group the similarly high plasma vitamin concentrations were recorded. Favourable values of these vitamins suggested that consumption of fruit and vegetables in autistic subjects is optimal. Autistic average vitamin E and A plasma concentrations (non-significantly changed in comparison to control group) were below-threshold with low percentage of over-threshold values. Insufficient vitamin E and A plasma values indicate lower consumption of food rich in vitamins A and E (e.g. whole-grain products, plant oils, oil seeds, nuts, fat spreads and dairy products). Autistic average lycopene concentration is lower in comparison to published non-Slovak data. Conclusions of this pilot study suggest that plasma concentrations of exogenous antioxidants, vitamins E and A, and lycopene in autistic subjects are insufficient (Tab. 1, Ref. 30). Full Text (Free, PDF) www.bmj.sk.

Nutritional determinants of plasma homocysteine.

The total Hcy, methionine, vitamin B12, folic acid and vitamin B6 blood concentrations were measured in apparently healthy adult subjects aged 20-30 years with three types of nutrition - 52 normal weight subjects of general population on traditional mixed diet (non-vegetarians), 52 normal weight vegetarians and 24 overweight and obese non-vegetarians. In the groups with lower methionine intake (vegetarians, normal weight non-vegetarians; methionine intake 0.45-2.12 g/day), Hcy values are dependent on vitamin B12 and folic acid. Vegetarian Hcy concentration is significantly increased and hyperhomocysteinemia was found in 35% of vegetarians vs 10% of non-vegetarians. Elevated Hcy values in vegetarians are the consequence of vitamin B12 deficiency - 31% of vegetarians with deficient serum values vs 2% of non-vegetarians (vitamin is not contained in plant food). Non-vegetarians are more deficient in folic acid (8% vs 0% in vegetarians) due to of lower consumption of food rich in folic acid (vegetables, whole grain products, pulses, seeds). The results suggest that in healthy population, a correct nutritional regime with an optimal intake of nutritional Hcy determinants is crucial for the maintenance of Hcy concentration in normal range and for the prevention of hyperhomocysteinemia (Tab. 2, Fig. 2, Ref. 27). Full Text (Free, PDF) www.bmj.sk.

Effect of acute acidosis on protein and amino acid metabolism in rats.

BACKGROUND & AIMS: Metabolic acidosis is a common finding in critical illness. The aim of the present study was to evaluate acute acidosis as a signal that induces changes in protein metabolism. METHODS: In the first study, Wistar rats were infused for 6h with HCl or saline resulting in blood pH7.30+/-0.03 and 7.46+/-0.02, respectively. The whole body protein metabolism was evaluated using L-[1-(14)C]leucine. In the second study, soleus and extensor digitorum longus muscles from normal rats were incubated in medium, pH7.4, 7.3 or 7.0. Protein metabolism was evaluated using L-[1-(14)C]leucine and tyrosine release. RESULTS: In the in vivo study we observed increased protein turnover-protein synthesis, proteolysis and leucine oxidation and more negative protein balance in rats with acidosis. There was no change in protein synthesis in gastrocnemius muscle. We observed an increase in plasma levels of most amino acids including branched-chain amino acids and a decrease in intracellular amino acid pool in skeletal muscle. In vitro decrease in pH of 0.1 had no effect on protein metabolism, decrease of 0.4 decreased protein turnover and leucine oxidation. CONCLUSION: Acute metabolic acidosis is a protein wasting condition. Direct effect of acidosis on skeletal muscle is under condition in vivo modified by neurohumoral regulations.

Protection of the rat liver against rewarming ischemic injury by University of Wisconsin solution.

BACKGROUND/AIM: University of Wisconsin (UW) solution has been proven able to prevent liver injury during cold ischemia. During rewarming ischemia, however, the efficacy of this solution in preserving hepatocyte function is unclear. The aim of the present study was to investigate to what extent UW solution protects rat liver during rewarming ischemia. METHODS: Livers were washed out with cool physiologic saline or with UW solution and subjected to rewarming ischemia for periods of 20 min or 45 min followed by reperfusion using a blood-free perfusion model. RESULTS: In comparison with controls, ischemia for 20 min in saline-treated livers led to mild depression of hepatocyte function, while UW solution afforded complete protection of the liver. In UW-treated livers, compared with saline-treated livers exposed to ischemia for 45 min, portal flow was slightly but significantly higher, bile production was increased by 62%, and lactate dehydrogenase leakage into the perfusate was reduced by 61%. In an attempt to explain mechanisms of liver protection by UW solution, we found that UW solution inhibited conversion of hypoxanthine into uric acid, but this effect was not associated with decreased degradation of adenine nucleotides in the liver during ischemia. Following 30 min reperfusion, UW solution increased tissue levels of adenosine triphosphate (not significantly) and adenosine diphosphate (significantly). Further, UW solution markedly reduced tumor necrosis factor-alpha release by the liver both after ischemia and after reperfusion. CONCLUSIONS: These results create the hypothesis that UW solution may protect liver tissue during ischemia in liver surgery as well as during the implantation stage of liver transplantation.

Influence of various biological matrices (plasma, blood microdialysate) on chromatographic performance in the determination of beta-blockers using an alkyl-diol silica precolumn for sample clean-up.

A HPLC column-switching system with LiChrospher RP-8 ADS precolumn was applied for the determination of beta-blockers (atenolol, pindolol, propranolol) in human plasma. The influence of biological matrices on the changes of the chromatographic parameters such as retention time, peak symmetry, area and selectivity were investigated. After injection of 5 ml plasma a decrease of retention times of the analytes was observed of up to 25% and an increase of asymmetry factors of up to 5%. Peak areas and selectivities were not changed. The observed effect could indicate changes of chromatographic performance caused by contributions of the analytical column or the ADS precolumn. The experiments with microdialysis excluded the contribution of the analytical column. A detailed investigation of experiments have been discussed in this paper.

Cold-preservation-induced sensitivity of rat hepatocyte function to rewarming injury and its prevention by short-term reperfusion.

With increasing time of cold preservation, levels of high-energy nucleotides in the liver are reducing. The authors hypothesized that cold preservation sensitizes hepatocyte function to ischemic injury occurring during graft rewarming and that the injury can be prevented by short-term reperfusion. Rat livers were cold-preserved in University of Wisconsin solution for 0 to 18 hours and ischemically rewarmed for 0 to 45 minutes to simulate the implantation stage of transplantation. Hepatobiliary function was assessed using a blood-free perfusion model. In comparison with controls, neither 18-hour preservation nor 45-minute ischemic rewarming significantly influenced hepatocyte function. Compared with livers subjected to 45-minute ischemic rewarming, livers subjected to 9-hour preservation and 45-minute rewarming, and livers subjected to 18-hour preservation and 45-minute rewarming exhibited, respectively: 3.8 and 24 times reduced bile production, 4.3- and 116-fold decreased taurocholate excretion, and 3.1 and 42 times depressed bromosulfophthalein excretion. Thirty-minute oxygenated warm reperfusion after 9- and 18-hour preservation nearly completely blunted sensitization of hepatocyte function to rewarming ischemia. The authors found that short-term oxygenated reperfusion restored adenine nucleotides in liver tissue to the values found before organ preservation and that reperfusion with energy substrate containing solutions increased tissue adenosine triphosphate concentration to a higher level than that found before preservation. In conclusion, sensitization of hepatocyte function to rewarming ischemia increases disproportionally with storage time, suggesting that this phenomenon may play a role in graft dysfunctions with increasing liver preservation time. Short-term oxygenated reperfusion of the liver may protect hepatocyte functions against warm ischemic insult, even after extended preservation.

Direct high-performance liquid chromatographic determination of (R)- and (S)-propranolol in rat microdialysate using on-line column switching procedures.

Two different column-switching HPLC systems (CSWs), employing restricted access material for initial pretreatment of biological samples, were developed for the determination of propranolol enantiomers in microdialysate. CSW 1 was a single-pump set-up based on an initial sample clean-up step with a RP-18 ADS precolumn coupled with an ovomucoid analytical column for direct drug enantioseparation. For the two-pump column set-up (CSW 2), a teicoplanin analytical column was applied for the enantioselective assay after initial sample pretreatment using a RP-8 ADS precolumn. The inter-day precision of the CSW 1 ranged from 0.5 to 5.1% for (R)-propranolol and from 5.1 to 10.5% for (S)-propranolol. The limit of detection (LOD) was set at 10 ng/ml and 15 ng/ml for (R)- and (S)-propranolol, respectively. Inter-day relative standard deviation values of the CSW 2 ranged from 1.1 to 9.9% for (R)-propranolol and from 1.3 to 9.6% for (S)-propranolol. The LOD of the method was 3.0 ng/ml for (R)-propranolol and 2.5 ng/ml for (S)-propranolol. Both approaches were successfully applied for stereoselective monitoring of unbound propranolol levels in rat microdialysates.