Prior ingestion of exogenous ketone monoester attenuates the glycaemic response to an oral glucose tolerance test in healthy young individuals.

KEY POINTS: The recent development of exogenous ketone supplements allows direct testing of the metabolic effects of elevated blood ketones without the confounding influence of widespread changes experienced with ketogenic diets or prolonged fasting. In the present study, we determined the effect of (R)-3-hydroxybutyl (R)-3-hydroxybutyrate ketone monoester on the glycaemic response and insulin sensitivity index during a 2 h oral glucose tolerance test (OGTT) in humans. The results obtained show that consuming a ketone monoester supplement 30 min prior to an OGTT reduced the glycaemic response and markers of insulin sensitivity without affecting insulin secretion. The findings of the present study provides evidence that ketone supplements could have therapeutic potential for future application as a glucose-lowering nutritional supplement. ABSTRACT: The main objectives of the present study were: (i) to determine whether acute ingestion of ketone monoester (Kme ); (R)-3-hydroxybutyl (R)-3-hydroxybutyrate impacts plasma glucose levels during a standardized oral glucose tolerance test (OGTT) and (ii) to compare changes in insulin concentrations and estimates of insulin sensitivity after acute Kme supplementation. Twenty healthy participants (n = 10 males/females) aged between 18 and 35 years took part in a randomized cross-over study. After an overnight fast, participants consumed a Kme supplement (ΔG®; TΔS Ltd, UK, Oxford, UK; 0.45 ml kg-1 body weight) or placebo (water) 30 min before completing a 75 g OGTT. Blood samples were collected every 15-30 min over 2.5 h. The participants and study personnel performing the laboratory analyses were blinded to the study condition. Kme acutely raised blood d-beta-hydroxybutyrate (ß-OHB) to 3.2 ± 0.6 mm within 30 min with levels remaining elevated throughout the entire OGTT. Compared to placebo, Kme significantly decreased the glucose area under the curve (AUC; -17%, P = 0.001), non-esterified fatty acid AUC (-44%, P < 0.001) and C-peptide incremental AUC (P = 0.005), at the same time as improving oral glucose insulin sensitivity index by ∼11% (P = 0.001). In conclusion, a Kme supplement that acutely increased ß-OHB levels up to ∼3 mm attenuated the glycaemic response to an OGTT in healthy humans. The reduction in glycaemic response did not appear to be driven by an increase in insulin secretion, although it was accompanied by improved markers of insulin sensitivity. These results suggest that ketone monoester supplements could have therapeutic potential in the management and prevention of metabolic diseases.

The active metabolite of leflunomide, A77 1726, attenuates inflammatory arthritis in mice with spontaneous arthritis via induction of heme oxygenase-1.

BACKGROUND: Leflunomide is a low-molecular-weight compound that is widely used in the treatment of rheumatoid arthritis. Although leflunomide is thought to act through the inhibition of the de novo pyrimidine synthesis, the molecular mechanism of the drug remains largely unknown. We investigated the antiarthritis effects and mechanisms of action of the active metabolite of leflunomide, A77 1726, in interleukin-1 receptor antagonist-knockout (IL-1Ra-KO) mice. METHODS: 14- to 15-week-old male IL-1Ra-KO mice were treated with 10 or 30 mg/kg A77 1726 via intraperitoneal injection three times per week for 6 weeks. The effects of A77 1726 on arthritis severities were assessed by clinical scoring and histological analysis. The serum concentrations of IL-1ß, tumor necrosis factor-α (TNF-α), and malondialdehyde were measured by enzyme-linked immunosorbent assay. Histologic analysis of the joints was performed using Safranin O, and immunohistochemical staining. The frequencies of interleukin-17-producing CD4+ T (Th17) cells were analyzed by flow cytometry. Heme oxygenase-1 (HO-1) expression in splenic CD4+ T cells isolated from A77 1726-treated arthritis mice were assessed by western blotting. RESULTS: A77 1726 treatment induced heme oxygenase-1 (HO-1) in Jurkat cells and primary mouse T cells. Interestingly, A77 1726 inhibited Th17 cell differentiation. In vivo, A77 1726 reduced the clinical arthritis severity of histological inflammation and cartilage destruction. The joints isolated from A77 1726-treated mice showed decreased expression of inducible nitric oxide synthase, nitrotyrosine, TNF-α, and IL-1ß. The serum levels of TNF-α, IL-1ß, and malondialdehyde were also decreased in A77 1726-treated mice. Whereas the number of Th17 cells in spleens was decreased in A77 1726-treated arthritis mice, a significant increase in the number of Treg cells in spleens was observed. Interestingly, HO-1 expression was significantly higher in splenic CD4+ T cells isolated from A77 1726-treated mice compared with those from vehicle-treated mice, whereas HO-1 expression of splenic non-CD4+ T cells did not differ between groups. CONCLUSION: The inhibitory effects of A77 1726 on joint inflammation and oxidative stress in autoimmune arthritis may be associated with HO-1 induction in CD4+ T cells.

A new way to produce hyperketonemia: use of ketone ester in a case of Alzheimer's disease.

BACKGROUND: Providing ketone bodies to the brain can bypass metabolic blocks to glucose utilization and improve function in energy-starved neurons. For this, plasma ketones must be elevated well above the ≤ 0.2 mM default concentrations normally prevalent. Limitations of dietary methods currently used to produce therapeutic hyperketonemia have stimulated the search for better approaches. METHOD: Described herein is a new way to produce therapeutic hyperketonemia, entailing prolonged oral administration of a potent ketogenic agent--ketone monoester (KME)--to a patient with Alzheimer's disease dementia and a pretreatment Mini-Mental State Examination score of 12. RESULTS: The patient improved markedly in mood, affect, self-care, and cognitive and daily activity performance. The KME was well tolerated throughout the 20-month treatment period. Cognitive performance tracked plasma ß-hydroxybutyrate concentrations, with noticeable improvements in conversation and interaction at the higher levels, compared with predose levels. CONCLUSION: KME-induced hyperketonemia is robust, convenient, and safe, and the ester can be taken as an oral supplement without changing the habitual diet.

Induction of EMT-like phenotypes by an active metabolite of leflunomide and its contribution to pulmonary fibrosis.

Drug-induced interstitial lung disease (ILD), particularly pulmonary fibrosis, is a serious clinical concern and myofibroblasts have been suggested to have a major role, with it recently being revealed that some of these myofibroblasts are derived from lung epithelial cells through epithelial-mesenchymal transition (EMT). In this study, we examined the EMT-inducing abilities of drugs known to induce ILD clinically. EMT-like phenotypes were induced by A771726, an active metabolite of leflunomide having an inhibitory effect on dihydroorotate dehydrogenase (DHODH). Smad-interacting protein 1 (a transcription factor regulating EMT) and the Notch-signaling pathway but not transforming growth factor-ß was shown to be involved in A771726-induced EMT-like phenotypes. When the cultures were supplemented with exogenous uridine, the A771726-induced EMT-like phenotypes and activation of the Notch-signaling pathway disappeared. Similarly, an A771726 analog without inhibitory activity on DHODH produced no induction, suggesting that this process is mediated through the inhibition of DHODH. In vivo, administration of leflunomide stimulated bleomycin-induced EMT-like phenomenon in pulmonary tissue, and exacerbated bleomycin-induced pulmonary fibrosis, both of which were suppressed by coadministration of uridine. Taken together, these findings suggest that leflunomide-dependent exacerbation of bleomycin-induced pulmonary fibrosis is mediated by stimulation of EMT of lung epithelial cells, providing the first evidence that drug-induced pulmonary fibrosis involves EMT of these cells.

[The action of emoxipin, lithium oxybutyrate and pikamilon on the blood circulation of the ischemic brain]. / Izuchenie deistviia émoksipina, litiia oksibutirata i pikamilona na krovoobrashchenie ishemizirovannogo mozga.

Acute experiments were conducted on rats under nembutal anesthesia to compare the efficacy of emoxipin with that of lithium oxybutyrate and picamilon in the postischemic period after preventive and therapeutic injections in various doses. Emoxipin proved to be most effective in prevention of postischemic non-restoration of the flow of blood in the brain and in preservation of the autoregulation responses of the cerebral vessels. The possible mechanisms of the effect of the drug are discussed.

[Use of antihypoxants in the acute period of myocardial infarction]. / Primenenie antigipoksantov v ostrom periode infarkta miokarda.

A total of 620 patients with acute myocardial infarction were followed up in order to assess the efficacy of antihypoxants as a component of intensive care. 385 of these patients, divided into groups of 20-40 subjects, were administered one of 12 antihypoxants or sessions of hyperbaric oxygenation during the acute period of the disease, the rest were treated traditionally. Analysis of clinical, laboratory, and prognostic values showed the highest protective effect of amtizol, lithium hydroxybutyrate, piracetam, and ubiquinone. Cytochrome C, riboxine, mildronate, and olifen were somewhat less active, and solcoseryl, bemitil, trimethasidine, and aspisol were the least effective. The protective potentialities of standard sessions of hyperbaric oxygenation were virtually null. The author proposes a parameter D, reflecting the difference between actual and predicted mortality, and the rating (score) system for assessing the routine laboratory diagnostic tests to be used together with the known criteria for evaluation of the protective effects of antihypoxants in patients with acute myocardial infarction.

[The effect of lithium oxybutyrate on the development of the fetus and progeny in alcoholic intoxication of male rats]. / Vliianie litiia oksibutirata na razvitie ploda i potomstva v usloviiakh alkogol'noi intoksikatsii samtsov krys.

The effect of lithium hydroxybutyrate on the development of the fetus and offsprings was studied on a model of alcohol intoxication of male rats. Under such conditions lithium hydroxybutyrate relieved completely the negative action of alcohol on the reproductive function, according to all parameters. The learning ability of the offsprings and their behavioral disorders in a stress situation caused by alcohol were normalized. Two-week administration of 100 mg/kg lithium hydroxybutyrate had no negative effect on the embryonal and postnatal development of the offsprings.

[The effect of lithium derivatives of GABA on blood circulation and metabolic indices in the brain under ischemia]. / Vliianie litievykh proizvodnykh GAMK na krovoobrashchenie i nekotorye pokazateli metabolizma v golovnom mozge v usloviiakh ishemii.

In acute experiments on anesthetized cats with cerebral ischemia in conditions of autohemoperfusion of cerebral and peripheral vessels with a stable volume of blood we found that lithium oxybutirate and new GABA derivatives: LOS 1-84 and LOS 5-79 affect the cerebral blood flow and metabolism in the brain. Prophylactic intravenous injection of lithium oxybutirate did not affect the development of postischemic hyperperfusion but inhibited postischemic hyperperfusion. The compounds prevent the development of postischemic phenomena and promote the recovery of metabolism in the brain.

Daily activity and persistent sleep-wake schedule disorders.

1. Patients with disorders of entrainment to external time cues such as delayed sleep phase syndrome (DSPS) and non-24-hour sleep-wake syndrome (HNS) were treated with non-pharmacological interventions and/or pharmacological agents. 2. Resetting the circadian clock with chronotherapy was easy in all DSPS patients, but it was not as easy to maintain the reset rhythm without additional therapy. Triazolam was effective in treating the phase delay that reappeared after chronotherapy. 3. Vitamin B12 (methylcobalamin) was strikingly effective in some patients with DSPS or HNS. 4. All the adolescent patients who complained of inability to attend school finally returned to their classes after treatment. Maintaining the reset rhythm in adolescent patients was easier than in adults.

[An electromyographic method for determining the antihypoxic activity of preparations]. / Elektromiograficheskii metod opredeleniia protivogipoksicheskoi aktivnosti preparatov.

To measure drug antihypoxic activity, an electromyographic method was worked out. The main idea of the method is to estimate the influence of these substances on the amplitude of slow electric waves of smooth muscles on an isolated strip of rat small intestine in situ. This parameter whose value directly depends on tissue pO2 was recorded under the conditions of artificial ischemia of the intestinal strip. Circulatory hypoxia was simulated by the clamping of mesentery vessels, and the time was determined, during which the amplitude of slow electric waves reduced to 1/3 of the initial value in control animals and rats treated beforehand with the drugs under study. Antihypoxic activity of the drugs was calculated as difference in these time intervals between experiment and control, given in per cent.

[The lithium oxybutyrate correction of disorders in higher nervous activity in the progeny of alcoholized male rats]. / Korrektsiia litiia oksibutiratom narushenii vysshei nervnoi deiatel'nosti potomstva alkogolizirovannykh krys-samtsov.

In experiments on rats it was shown that alcohol administered intragastrically in a dose of 8 g/kg for 4 weeks produced long-term disturbances of CNS function in the offspring similar to those observed under clinical conditions. Early postnatal administration of lithium oxybutyrate (from the 8th through the 14th day of life) was found to prevent the development of the disturbances.

Suppression by gamma-hydroxybutyric acid of ethanol withdrawal syndrome in rats.

The ability of gamma-hydroxybutyric acid to suppress ethanol withdrawal syndrome was tested in male rats rendered physically dependent on ethanol by several intragastric administrations of ethanol (9-15 g/kg daily for 7 days). Gamma-hydroxybutyrate (0.25, 0.50 and 1.00 g/kg i.p.), administered 8 hr after the last ethanol dose, produced a dose-dependent inhibition of withdrawal signs such as tremors and audiogenically-induced seizures; the highest dose tested suppressed all ethanol withdrawal symptoms.

[Effect of sodium oxybutyrate on the development of a staphylococcal intoxication]. / Vliianie natriia oksibutirata na razvitie stafilokokkovoi intoksikatsii.

Sodium oxybutyrate (200 and 400 mg/kg) was found to increase life expectancy of the animals poisoned with staphylococcus toxin. The improvement of the blood supply to the bulbar structure of the brain as well as normalization of hemorheological parameters probably underlie the protective effect of the drug.

Protection by GABA agonists, gamma-hydroxybutyric acid, and valproic acid against seizures evoked in epileptic chicks by hyperthermia.

With microwave diathermy, febrile seizures were produced in epileptic chicks aged 2-5 days. Drugs that enhance GABAergic activity (i.e., GABA, muscimol, and progabide), as well as valproic acid and gamma-hydroxybutyric acid, produced dose-dependent increases in latency to onset of seizures.

[Dynamics of carrageenin-induced inflammation after use of lithium oxybutyrate]. / Dinamika karrageninovogo vospaleniia v usloviiakh primeneniia oksibutirata litiia.

Lithium hydroxybutyrate (200 mg/kg) has been shown to depress the development of carrageenan inflammation. Subcutaneous drug injection in chronic inflammation of the mucous membrane in the hamster cheek pouch restored the blood flow, checked dilatation of the blood vessels, decreased their permeability and prevented necrosis of the mucous membranes. Subcutaneous drug injection depressed all the signs of both phases of acute inflammatory reaction in the rat hind foot and promoted preservation of the hind foot function. Therefore, lithium hydroxybutyrate may be an effective preparation for the treatment of inflammation.

[Sodium oxybutyrate correction of the disorders in higher nervous activity in the progeny of alcoholized animals]. / Korrektsiia natriia oksibutiratom narushenii vysshei nervnoi deiatel'nosti potomstva alkogolizirovannykh zhivotnykh.

Alcoholization of female rats before pregnancy (8 g/kg) or during pregnancy (4 g/kg) leads to disturbances in the development of the offspring higher nervous activity manifested by impaired learning abilities, disordered emotional reactivity, reduced capacity to overcome stress-situation, deficit of GABAergic inhibitory processes in the cerebral cortex. An early postnatal administration of sodium hydroxybutyrate in a dose of 50 mg/kg prevents the development of the above mentioned disturbances of the higher nervous activity and neurophysiological alterations.

[Effect of lithium oxybutyrate on lipid metabolic changes in pituitrin-induced pulmonary edema]. / Vliianie oksibutirata litiia na izmeneniia lipidnogo obmena pri pituitrinovom oteke legkikh.

The experiments on white rats have confirmed that the development of lung edema following pituitrin infusion is characterized by considerable changes in phospholipid and cholesterol lung metabolism and cholesterol blood metabolism. Lithium hydroxybutyrate preinjection at a dose of 400 mg/kg prevented a decrease in cholesterol lung content and an increase in cholesterol blood plasma level which was accompanied by less prominent lung edema.