Targeted metabolome profiling by dual-probe microdialysis sampling and treatment using Gardenia jasminoides for rats with type 2 diabetes.

Diabetes causes a variety of end-stage organ complications, including diabetic nephropathy. Metabolomics offers an approach for characterizing biofluid metabolic changes, but studies focusing on diabetic nephropathy are limited due to the loss of tissue-specific metabolic information. A microdialysis application for the sampling of intact endogenous metabolites has been developed, utilizing two probes simultaneously inserted into the kidney tissues and jugular vein of rats with type 2 diabetes. The comprehensive and quantitative analysis of 20 diagnostic biomarkers closely realated to type 2 diabetes and its complications were performed. Results indicated that amino acid and nucleotide levels were lower in diabetic rats, revealing that the metabolic pathways of amino acid, as well as purine and pyrimidine, were disturbed. Targeted metabolomics using mass spectrometry was performed to find potential therapeutic biomarkers and related metabolic pathways of Gardenia jasminoides (G. jasminoides) for treating diabetes. Results suggested that seven biomarkers in the kidney and five biomarkers in the blood were related to G. jasminoides. In addition, the marked perturbations of pathways were regulated after treatment with G. jasminoides, including amino acid metabolism and purine metabolism. These biomarkers and metabolic pathways provided new understanding for molecular mechanisms of G. jasminoides for treating diabetes and its complications.

Pharmacokinetic interaction between Kaempferia parviflora extract and sildenafil in rats.

Kaempferia parviflora (KP) is a plant widely used in Southeast Asia. Its major compounds are 3,5,7,3',4'-pentamethoxyflavone (PMF), 5,7,4'-trimethoxylflavone (TMF), and 5,7-dimethoxyflavone (DMF). This study investigated the effect of KP extract on the blood levels and pharmacokinetics of sildenafil co-administration in rats. Rats were randomly assigned to four groups. Groups 1, 2, and 3 were given sildenafil 20 mg/kg daily for 9 days. On days 4-9 of each treatment period, the treated rats received KP extract (250 mg/kg) and vehicle (groups 2 and 3, respectively). Group 4 received KP extract only (250 mg/kg daily for 9 days). Daily blood concentrations of sildenafil, PMF, TMF, and DMF were determined by HPLC to evaluate the daily blood level interactions. Additional blood samples were collected at various times on the last day of treatment to evaluate the pharmacokinetic interactions. The KP extract decreased blood levels of sildenafil on the first day of co-administration by 95 % but the percentage reduction was insignificant on subsequent days. When co-administered with KP extract, the area under the curve (AUC), maximum concentration (C max), and half-life (T 1/2) of sildenafil were decreased by 60-65, 40-52, and 32-54 %, respectively, with the elimination rate constant (K e) increased by 37-77 %. In addition, PMF, TMF, and DMF concentrations and their AUC, C max, T max, K e, and T 1/2 values were changed after co-administration of KP extract and sildenafil.

Effect of a wild blueberry (Vaccinium angustifolium) drink intervention on markers of oxidative stress, inflammation and endothelial function in humans with cardiovascular risk factors.

PURPOSE: Wild blueberries (WB) (Vaccinium angustifolium) are rich sources of polyphenols, such as flavonols, phenolic acids and anthocyanins (ACNs), reported to decrease the risk of cardiovascular and degenerative diseases. This study investigated the effect of regular consumption of a WB or a placebo (PL) drink on markers of oxidative stress, inflammation and endothelial function in subjects with risk factors for cardiovascular disease. METHODS: Eighteen male volunteers (ages 47.8 ± 9.7 years; body mass index 24.8 ± 2.6 kg/m²) received according to a cross-over design, a WB (25 g freeze-dried powder, providing 375 mg of ACNs) or a PL drink for 6 weeks, spaced by a 6-week wash-out. Endogenous and oxidatively induced DNA damage in blood mononuclear cells, serum interleukin levels, reactive hyperemia index, nitric oxide, soluble vascular adhesion molecule concentration and other variables were analyzed. RESULTS: Wild blueberry drink intake significantly reduced the levels of endogenously oxidized DNA bases (from 12.5 ± 5.6 % to 9.6 ± 3.5 %, p ≤ 0.01) and the levels of H2O2-induced DNA damage (from 45.8 ± 7.9 % to 37.2 ± 9.1 %, p ≤ 0.01), while no effect was found after the PL drink. No significant differences were detected for markers of endothelial function and the other variables under study. CONCLUSIONS: In conclusion, the consumption of the WB drink for 6 weeks significantly reduced the levels of oxidized DNA bases and increased the resistance to oxidatively induced DNA damage. Future studies should address in greater detail the role of WB in endothelial function.

Gallic acid intake induces alterations to systems metabolism in rats.

Gallic acid (GA) and its metabolites are polyphenolic compounds present in daily diets and herbal medicines. To understand the GA effects on the endogenous metabolism of mammals, we systematically analyzed the metabonomic responses of rat plasma, liver, urine, and feces to a single GA dosage of 120 and 600 mg/kg, which were below the no-obvious-adverse-effect-level of 1 g/kg for rats. Clinical chemistry and histopathological assessments were conducted to provide complementary information. Our results showed that GA intake induced significant metabonomic changes in multiple rat biological matrices. Such changes were more outstanding in liver than in the other matrices and clearly showed dose- and time-dependence. The results suggested GA-induced promotion of oxidative stress as the major effect. High-dose GA caused significant metabolic changes involving glycogenolysis, glycolysis, TCA cycle, and metabolism of amino acids, purines, and pyrimidines, together with gut microbiota functions. Low-dose GA only caused some urinary metabonomic changes and to a much less degree. The GA-induced liver metabonomic changes were not completely recoverable within a week, although such recovery completed in plasma, urine, and feces within 80 h. These findings provided new essential information on the effects of dietary polyphenols and demonstrated the great potential of this nutrimetabonomics approach.

Effect of sauna bathing and beer ingestion on plasma concentrations of purine bases.

To determine whether sauna bathing alone or in combination with beer ingestion increases the plasma concentration of uric acid, 5 healthy subjects were tested. Urine and plasma measurements were performed before and after each took a sauna bath, ingested beer, and ingested beer just after taking a sauna bath, with a 2-week interval between each activity. Sauna bathing alone increased the plasma concentrations of uric acid and oxypurines (hypoxanthine and xanthine), and decreased the urinary and fractional excretion of uric acid, while beer ingestion alone increased the plasma concentrations and urinary excretion of uric acid and oxypurines. A combination of both increased the plasma concentration of uric acid and oxypurines, and decreased the urinary and fractional excretion of uric acid, with an increase in the urinary excretion of oxypurines. The increase in plasma concentration of uric acid with the combination protocol was not synergistic as compared to the sum of the increases by each alone. Body weight, urine volume, and the urinary excretion of sodium and chloride via dehydration were decreased following sauna bathing alone. These results suggest that sauna bathing had a relationship with enhanced purine degradation and a decrease in the urinary excretion of uric acid, leading to an increase in the plasma concentration of uric acid. Further, we concluded that extracellular volume loss may affect the common renal transport pathway of uric acid and xanthine. Therefore, it is recommended that patients with gout refrain from drinking alcoholic beverages, including beer, after taking a sauna bath, since the increase in plasma concentration of uric acid following the combination of sauna bathing and beer ingestion was additive.

[Vasoactive effects of femostone in women with metabolic postmenopausal syndrome]. / Vazoaktivnye éffekty femostona u zhenshchin s metabolicheskim postmenstrual'nym sindromom.

The metabolic postmenopausal syndrome (MPS) is characterized by a complex of metabolic disorders: lipid (76%), purin (56%), calcium-phosphorus (61%). There is also a rise in amplitude of spontaneous platelet aggregation (61%) and fibrinogen levels (78%). Clinically, these phenomena manifest in arterial hypertension and defective cerebral circulation. An estrogen-histogen drug femoston was tried for clinical effectiveness and tolerance in 40 females with MPS. Femoston was used in long-term regimen for 12 months. The response was observed in all the patients, all the above parameters underwent positive changes. The drug was well tolerated, side effects were moderate. No withdrawals occurred.

Cardiovascular and pulmonary response to oral administration of ATP in rabbits.

Extracellular purines such as ATP and adenosine participate in the regulation of cardiovascular and respiratory functions through specific P1 and P2 purine receptors. These properties have mainly been described after intravenous infusion. Experiments reported herein were designed to explore the possible effect of oral ATP administration (3 or 20 mg. kg(-1). day(-1)) on vascular, cardiac, and pulmonary functions in rabbits. Whereas a unique oral dose of ATP has no effect, chronic supplementation during 14 days reduces peripheral vascular resistance, pulmonary resistance, and respiratory frequency and increases arterial PO(2). No effect on central blood pressure and heart rate is observed, but an increase of the left ventricular work index is noticed subsequent to the diminution of vascular resistance. Rather similar cardiovascular modifications are observed in rabbits given 20 mg. kg(-1). day(-1) adenosine for 14 days but without variation of respiratory parameters. These original effects of repeated oral treatment with ATP may result from an adaptive metabolic response to nucleoside supplementation that might affect the turnover of extracellular purines leading to P1- and/or P2-receptor activation.

The effect of a nucleotide-nucleoside solution on hepatic regeneration in rats after partial hepatectomy and in primary monolayer culture of hepatocytes.

Purine and pyrimidine metabolism is a key process after hepatic surgery. To evaluate the effect of purine and pyrimidine supplementation on hepatic regeneration, the following clinical in vitro and in vivo experiments were performed. Changes in blood nucleotides, nucleosides and nucleobase were analyzed by high performance liquid chromatography in patients and rats after partial hepatectomy. The effect of supplementation of nucleotide-nucleoside solution (OG-VI) or their components on nucleic acids syntheses in primary monolayer cultured hepatocytes and preoperative intraperitoneal injection of OG-VI on hepatic regeneration in the partially hepatectomized rats were evaluated. Blood purine and pyrimidine levels in patients change after hepatectomy and their changes indicate increased salvage synthesis of purine and pyrimidine in the regenerating liver. Addition of appropriate amounts of inosine, GMP, uridine, or thymidine, the substrates for salvage purine and pyrimidine syntheses, to primary cultures of hepatocytes enhanced both DNA and RNA syntheses by the salvage and de novo pathways. The OG-VI mixture also enhanced the syntheses of DNA and RNA. Preoperative administration of OG-VI to partially-hepatectomized rats enhances hepatic DNA synthesis in a way similar to the in vitro study.

L-carnitine and coenzyme Q10 protective action against ischaemia and reperfusion of working rat heart.

The protective effect of L-carnitine, coenzyme Q10 and their combination on haemodynamic and metabolic variables has been investigated in isolated perfused working rat hearts after 10 min of global normothermic ischaemia followed by 60 min of reperfusion. In untreated rats or in rats treated only with L-carnitine or with coenzyme Q10, this experimental condition did not induce any irreversible myocardial injury as measured by leakage of cardiac enzymes; however, it decreased some haemodynamic parameters such as cardiac output and minute work, as well as the ATP concentration and the total adenine nucleotide pool. No variations in haemodynamic and metabolic parameters were observed in the rats treated with L-carnitine plus coenzyme Q10. In the perfusate of the hearts of the rats treated with both compounds, a lower purine release (a good index of myocardial energy balance) was also obtained. Although the molecular mechanisms remain to be defined, it appears that the association of L-carnitine and coenzyme Q10 is more effective than using these compounds separately. The complementary and synergic actions of L-carnitine and coenzyme Q10 on metabolism and against peroxidation by oxygen reaction species may explain the efficacy of their association.

Adenosine triphosphate turnover in humans. Decreased degradation during relative hyperphosphatemia.

The regulation of ATP metabolism by inorganic phosphate (Pi) was examined in five normal volunteers through measurements of ATP degradation during relative Pi depletion and repletion states. Relative Pi depletion was achieved through dietary restriction and phosphate binders, whereas a Pi-repleted state was produced by oral Pi supplementation. ATP was radioactively labeled by the infusion of [8(14)C]adenine. Fructose infusion was used to produce rapid ATP degradation during Pi depletion and repletion states. Baseline measurements indicated a significant decrease of Pi levels during phosphate depletion and no change in serum or urinary purines. Serum values of Pi declined 20 to 26% within 15 min after fructose infusion in all states. Urine measurements of ATP degradation products showed an eightfold increase within 15 min after fructose infusion in both Pi-depleted and -supplemented states. Urinary radioactive ATP degradation products were fourfold higher and urinary purine specific activity was more than threefold higher during Pi depletion as compared with Pi repletion. Our data indicate that there is decreased ATP degradation to purine end products during a relative phosphate repletion state as compared to a relative phosphate depletion state. These data show that ATP metabolism can be altered through manipulation of the relative Pi state in humans.

One-carbon metabolism in lectin-activated human lymphocytes.

Serine is an essential amino acid for the lectin-mediated transformation of human peripheral blood lymphocytes due to the inability of this cell to synthesize sufficient quantities via either the phosphorylated pathway or by reversal of the serine hydroxymethyltransferase reaction to meet the metabolic demands. The level of intracellular serine is tightly regulated, and the culture medium concentration for optimum cellular transformation falls within a relatively narrow range. The three-carbon atom of serine is the major source of one-carbon units required for purine and pyrimidine nucleotide biosynthesis, but the key effect of both serine deprivation and of high medium serine levels would appear to be on protein synthesis. Although an alternative source of one-carbon units, as provided by high levels of formate in the culture medium, can partially reverse the effects of serine deprivation, the only other demonstrable source of one-carbon units, tryptophan, requires serine for its incorporation and subsequent metabolism. Methionine is also essential for lymphocyte transformation and is involved in the synthesis of a small amount of phosphatidylcholine, although most of this phospholipid is provided by choline and lysophosphatidylcholine from the serum-supplemented culture medium.

Study of the purine metabolism in obese patients during a slimming diet.

Uric acid assays were performed in the blood serum from 20 obese patients (19 women and 1 man, with a mean age of 39.75 +/- 8.16 years), before and after an average period of three weeks of hypocaloric diet (400-500 cal/day) during which they lost about 8 kg of body weight each. The variations of uricemia were followed up in relation with the weight loss and with the presence or absence of changes in the plasma lipid values. The mean rise of uricemia in the whole lot of subjects, as well as in those who lost more than 8 kg b.w. were weakly significant, as compared to the initial values. In the patients distributed according to the changes of lipid values, the increase was not significant. In conditions of rapid weight loss, even when the diet was supplemented by 70 g proteins/day, the serum uric acid values rose up to the limit of plasma urate solubility. This imposes a periodical check-up of uricemia, at the beginning, in the course and at the end of the periods of rapid weight loss, in view of detecting and correcting the eventual disorders which might occur in such conditions.