Pharmacokinetics of high-dose oral thiamine hydrochloride in healthy subjects

Whole blood thiamine, intravenous thiamine supplementation and delirium occurrence in the intensive care unit: retrospective cohort analyses

BACKGROUND

Thiamine di-phosphate is an essential cofactor in glucose metabolism, glutamate transformation and acetylcholinesterase activity, pathways associated with delirium occurrence. We hypothesised that a deficiency in whole blood thiamine and intravenous thiamine supplementation could impact delirium occurrence.

AIM

To establish whether a deficiency in whole blood thiamine and/or intravenous thiamine supplementation within 72 h of intensive care admission is associated with delirium occurrence.

METHOD

The first dataset was secondary analysis of a previous study in an intensive care unit in the Netherlands, reported in 2017. The second dataset contained consecutive intensive care admissions 2 years before (period 1: October 2014 to October 2016) and after (period 2: April 2017 to April 2019) routine thiamine supplementation was introduced within 72 h of admission. Delirium was defined as a positive Confusion Assessment Method-Intensive Care Unit score(s) in 24 h.

RESULTS

Analysis of the first dataset (n = 57) using logistic regression showed no relationship between delirium and sepsis or whole blood thiamine, but a significant association with age (p = 0.014). In the second dataset (n = 3074), 15.1% received IV thiamine in period 1 and 62.6% during period 2. Hierarchical regression analysis reported reduction in delirium occurrence in the second period; this did not reach statistical significance, OR = 0.81 (95% CI 0.652-1.002); p = 0.052.

CONCLUSION

No relationship was detected between whole blood thiamine and delirium occurrence on admission, at 24 and 48 h. It remains unclear whether routine intravenous thiamine supplementation during intensive care admission impacts delirium occurrence. Further prospective randomised clinical trials are needed.

High-dose oral thiamine versus placebo for chronic fatigue in patients with primary biliary cholangitis: A crossover randomized clinical trial

BACKGROUND & AIMS

Fatigue has high negative impact on many patients with primary biliary cholangitis (PBC) and treatment options are limited. Recently we showed favorable effects of four weeks of high-dose thiamine treatment on fatigue in patients with inflammatory bowel disease. We aimed to investigate the effect and safety of high-dose (600-1800 mg daily) oral thiamine treatment on chronic fatigue in patients with PBC.

METHODS

Randomized, double-blinded, placebo-controlled crossover trial including patients with severe PBC-related fatigue. Participants were allocated 1:1 to either group 1) 4 weeks of high-dose thiamine, 4 weeks of washout, and 4 weeks of placebo; or group 2) 4 weeks of placebo, washout, and high-dose thiamine, respectively. Fatigue severity was quantified using the fatigue subscale of the PBC-40 questionnaire. The primary outcome was a fatigue reduction of ≥ 5 points after 4 weeks of high-dose thiamine treatment.

RESULTS

We enrolled 36 patients; 34 completed the study. The overall mean reduction in fatigue was 5.0 points (95% CI: 2.5 to 7.5; p < 0.001) for the combined group 1 and group 2. Crossover analysis showed a mean increase in fatigue of 0.3 points (95% CI: -4.2 to 3.8) after high-dose thiamine treatment compared to a 1.4 points (95% CI: 6.2 to -3.4) mean reduction after placebo (p = 0.55). Only mild and transient adverse events were recorded.

CONCLUSION

Four weeks of high-dose oral thiamine treatment in patients with PBC was well tolerated and safe. However, high-dose thiamine was not superior to placebo in reducing PBC-related fatigue.

TRIAL REGISTRATION

The trial was registered in the ClinicalTrials.gov (NCT04893993) and EudraCT (2020-004935-26).

B-vitamins, related vitamers, and metabolites in patients with quiescent inflammatory bowel disease and chronic fatigue treated with high dose oral thiamine

BACKGROUND

High doses of oral thiamine improve clinical fatigue scores in patients with quiescent inflammatory bowel disease (IBD) and chronic fatigue. In this study we analysed plasma samples obtained in a randomised clinical trial and aimed compare levels of vitamins B1, B2, B3 and B6, and their related vitamers and metabolites in patients with IBD, with or without chronic fatigue and with or without effect of high dose oral thiamine for chronic fatigue.

METHODS

Blood samples from patients with fatigue were drawn prior and after thiamine exposure and only once for patients without fatigue. A wide panel of analysis were done at Bevital AS Lab.

RESULTS

Concentration of flavin mononucleotide (FMN) was lower in patients with chronic fatigue compared to patients without fatigue (p = 0.02). Patients with chronic fatigue who reported a positive effect on fatigue after 4 weeks of high dose thiamine treatment had a statistically significantly lower level of riboflavin after thiamine treatment (p = 0.01).

CONCLUSION

FMN and Riboflavin were associated with chronic fatigue in patients with quiescent IBD. Levels of other B vitamins and metabolites were not significantly different between the investigated groups or related to effect of the thiamine intervention.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov study identifier NCT036347359. Registered 15 August 2018, https://clinicaltrials.gov/study/NCT03634735?cond=Inflammatory%20Bowel%20Diseases&intr=Thiamine&rank=1.

Availability of abundant thiamine determines efficiency of thermogenic activation in human neck area derived adipocytes

Brown/beige adipocytes express uncoupling protein-1 (UCP1) that enables them to dissipate energy as heat. Systematic activation of this process can alleviate obesity. Human brown adipose tissues are interspersed in distinct anatomical regions including deep neck. We found that UCP1 enriched adipocytes differentiated from precursors of this depot highly expressed ThTr2 transporter of thiamine and consumed thiamine during thermogenic activation of these adipocytes by cAMP which mimics adrenergic stimulation. Inhibition of ThTr2 led to lower thiamine consumption with decreased proton leak respiration reflecting reduced uncoupling. In the absence of thiamine, cAMP-induced uncoupling was diminished but restored by thiamine addition reaching the highest levels at thiamine concentrations larger than present in human blood plasma. Thiamine is converted to thiamine pyrophosphate (TPP) in cells; the addition of TPP to permeabilized adipocytes increased uncoupling fueled by TPP-dependent pyruvate dehydrogenase. ThTr2 inhibition also hampered cAMP-dependent induction of UCP1, PGC1a, and other browning marker genes, and thermogenic induction of these genes was potentiated by thiamine in a concentration dependent manner. Our study reveals the importance of amply supplied thiamine during thermogenic activation in human adipocytes which provides TPP for TPP-dependent enzymes not fully saturated with this cofactor and by potentiating the induction of thermogenic genes.

In Vivo Evaluation of Thiamine Hydrochloride with Gastro-Retentive Drug Delivery in Healthy Human Volunteers Using Gamma Scintigraphy

A floating tablet system containing thiamine hydrochloride, a model drug with a narrow absorption window, was evaluated. The tablet was found to have a floating lag time of less than 30 s with a sustained drug release over 12 h during in vitro dissolution studies. The gastro-retentive property of the tablet in relation to the bioavailability of thiamine was determined in healthy human volunteers using gamma scintigraphy under fasted and fed conditions. The gastro-retentive time of the floating tablet could be prolonged up to 10 h under the fed state, compared to about 1.8 h in the fasted state. The prolonged gastric retention under the fed state resulted in a 2.8-fold increase in oral bioavailability of thiamine compared to that of the fasted state. There was also a 1.4-fold increase in thiamine absorption compared to that of a conventional immediate release tablet in the fed state. In the fasted state, the extent of thiamine absorption from the floating tablet was only about 70% of that absorbed from the immediate release tablet. Thus, to achieve a better performance, such floating tablet systems should be administered under a fed condition, to prolong the gastric retention time.

Sustainable bio-based antimicrobials derived from fatty acids: Synthesis, safety, and efficacy

Some conventional sanitizers and antibiotics used in food industry may be of concerns due to generation of toxic byproducts, impact on the environment, and the emergence of antibiotic resistance bacteria. Bio-based antimicrobials can be an alternative to conventional sanitizers since they are produced from renewable resources, and the bacterial resistance to these compounds is of less concern than those of currently used antibiotics. Among the bio-based antimicrobial compounds, those produced via either fermentation or chemical synthesis by covalently or electrovalently attaching specific moieties to the fatty acid have drawn attention in recent years. Disaccharide, arginine, vitamin B1, and phenolics are linked to fatty acids resulting in the production of sophorolipid, lauric arginate ethyl ester, thiamin dilauryl sulfate, and phenolic branched-chain fatty acid, respectively, all of which are reported to exhibit antimicrobial activity by targeting the cell membrane of the bacteria. Also, studies that applied these compounds as food preservatives by combining them with other compounds or treatments have been reviewed regarding extending the shelf life and inactivating foodborne pathogens of foods and food products. In addition, the phenolic branched-chain fatty acids, which are relatively new compounds compared to the others, are highlighted in this review.

Intermediate role of gut microbiota in vitamin B nutrition and its influences on human health

Vitamin B consists of a group of water-soluble micronutrients that are mainly derived from the daily diet. They serve as cofactors, mediating multiple metabolic pathways in humans. As an integrated part of human health, gut microbiota could produce, consume, and even compete for vitamin B with the host. The interplay between gut microbiota and the host might be a crucial factor affecting the absorbing processes of vitamin B. On the other hand, vitamin B supplementation or deficiency might impact the growth of specific bacteria, resulting in changes in the composition and function of gut microbiota. Together, the interplay between vitamin B and gut microbiota might systemically contribute to human health. In this review, we summarized the interactions between vitamin B and gut microbiota and tried to reveal the underlying mechanism so that we can have a better understanding of its role in human health.

Biological Properties of Vitamins of the B-Complex, Part 1: Vitamins B1, B2, B3, and B5

This review summarizes the current knowledge on essential vitamins B₁, B₂, B₃, and B₅. These B-complex vitamins must be taken from diet, with the exception of vitamin B₃, that can also be synthetized from amino acid tryptophan. All of these vitamins are water soluble, which determines their main properties, namely: they are partly lost when food is washed or boiled since they migrate to the water; the requirement of membrane transporters for their permeation into the cells; and their safety since any excess is rapidly eliminated via the kidney. The therapeutic use of B-complex vitamins is mostly limited to hypovitaminoses or similar conditions, but, as they are generally very safe, they have also been examined in other pathological conditions. Nicotinic acid, a form of vitamin B₃, is the only exception because it is a known hypolipidemic agent in gram doses. The article also sums up: (i) the current methods for detection of the vitamins of the B-complex in biological fluids; (ii) the food and other sources of these vitamins including the effect of common processing and storage methods on their content; and (iii) their physiological function.

Long-term maintenance treatment with 300 mg thiamine for fatigue in patients with inflammatory bowel disease: results from an open-label extension of the TARIF study

OBJECTIVE AND AIMS

Fatigue is common in inflammatory bowel disease (IBD). In a RCT we demonstrated reductions in fatigue after 4 weeks' treatment with high-dose oral thiamine. We aimed to investigate whether 300 mg thiamine daily for 12 weeks could maintain the achieved levels of fatigue in patients with IBD after a 4-week intervention with high-dose thiamine; and evaluate the effect of a 6-month period where patients were free to take oral thiamine.

METHODS

A randomised, open-label, controlled trial, performed as a long-term extension (LTE) study of an initial randomised, high-dose thiamine trial. Patients were allocated 1:1 to 300 mg oral thiamine or no thiamine for 12 weeks. Subsequently, the patients were allowed to self-treat with over-the-counter (OTC) oral thiamine 6-month.

RESULTS

Regardless of allocation in the LTE study fatigue severity increased in the study period. No significant effect of 300 mg oral thiamine were found, when stratifying for initial allocation in the high-dose study or fatigue level at entry in the LTE study. Patients who took OTC thiamine had lower level of fatigue 6 month later (7.8; 95% CI: 5.5-10.1) when compared to the remains (11.0; 95% CI: 9.2-12.8) (p = .02). After the 6-months follow-up without restrictions, 66% of patients had reached normal fatigue levels.

CONCLUSIONS

We found no beneficial effect on fatigue from thiamine taken in doses of 300 mg per day for 12 weeks following high-dose treatment. After a 6-months follow-up without restrictions 66% had reached a normal level of fatigue.

CLINICAL TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov under study identifier NCT03634735.

Pharmacokinetics of thiamine (vitamin B1) in adult horses after administration of three single intravenous doses

Thiamine is a vital co-factor for several anti-inflammatory and antioxidant processes that are critical for mitigation of sepsis-associated inflammation, but pharmacokinetic (PK) analysis has not been reported in horses. We hypothesized that IV thiamine hydrochloride (TH) at increasing dosages would result in corresponding increases in plasma thiamine concentrations without causing adverse effects. A randomized cross-over study was performed in 9 healthy horses that each received TH at 5, 10, and 20 mg/kg IV. Blood was collected immediately prior to drug administration and at several time points thereafter. High-performance liquid chromatography with mass spectrometry was used to quantify thiamine concentrations at each time point. Non-compartmental PK methods showed that IV TH resulted in supraphysiologic plasma concentrations with a short half-life (0.77-1.12 h) and no adverse clinical signs were observed. The terminal rate constant decreased as the dosage increased (p < .0001) and clearance significantly decreased at the 20 mg/kg dosage (p = .0011). The area under the curve (AUC) increased in a non-linear fashion. These findings suggest that thiamine follows non-linear elimination kinetics in horses, which is likely due to saturation of renal elimination. Future studies are needed to identify therapeutic plasma concentrations and develop thiamine dosing recommendations for horses.

The Potential of a Site-Specific Delivery of Thiamine Hydrochloride as a Novel Insect Repellent Exerting Long-Term Protection on Human Skin: In-vitro, Ex-vivo Study and Clinical Assessment

Thiamine hydrochloride (TH) was thought to exert a good insect repellent activity. The purpose of this work was to develop a formulation that releases TH in sustained regimen on human skin. Long lasting protection against mosquito bites was achieved. Pullulan acetate (PA) was used to prepare TH nanospheres. Optimal system was incorporated in Pluronic® hydrogel. Formulae were tested for in-vitro release and ex-vivo permeation. Complete protection time (CPT) was done adopting Kaplan-Meier survival function for the synthetic repellent (DEET), TH solution and nanospheres in hydrogel. Release profile of TH solution, nanospheres and nanosphere-loaded hydrogel (DG) demonstrated an added effect of DG, where t _1/2 was 11.2 ± 1.4 h. SEM for DG showed homogenous dispersion of nanospheres inside the matrix of the gel. Ex-vivo permeation showed only 0.761 ± 0.04% of TH in hydrogel permeated the skin after 12 h, while 44.98 ± 3.2% permeated when TH solution was applied. Clinical study revealed a significant difference in CPT between TH solution with either DEET or (DG) (p<0.05), and no significant difference between DEET and DG with CPT 400 ± 31 and 360 ± 18 min, respectively (P > 0.05). The high efficacy of TH-loaded hydrogel rendered it a successful alternative for DEET, offering long protection against mosquito bites.

Repurposing Treatment of Wernicke-Korsakoff Syndrome for Th-17 Cell Immune Storm Syndrome and Neurological Symptoms in COVID-19: Thiamine Efficacy and Safety, In-Vitro Evidence and Pharmacokinetic Profile

Coronavirus disease identified in 2019 (COVID-19) can be complicated by the Th17 cell-mediated IL-17 proinflammatory response. We tested if thiamine can effectively lower the Th17 response in a clinical study [Proinflammatory state in alcohol use disorder patients termed as disease controls (DC)] and corroborated the results using an in vitro study. We developed an effective dose range and model for key pharmacokinetic measures with the potential of targeting the cytokine storm and neurological symptoms of COVID-19. Three-week 200 mg dose of thiamine was administered to sixteen DC patients. Eight healthy volunteers (HV) were also included in this investigation. A subsequent in vitro study was performed to validate the effectiveness of thiamine [100 mg/day equivalent (0.01 μg/ml)] treatment in lowering the Th17 proinflammatory response in a mouse macrophage cell line (RAW264.7) treated with ethanol. Based on recent publications, we compared the results of the IL-17 response from our clinical and in vitro study to those found in other proinflammatory disease conditions (metabolic conditions, septic shock, viral infections and COVID-19) and effective and safe dose ranges of thiamine. We developed a pharmacokinetic profile for thiamine dose range as a novel intervention strategy in COVID-19. DC group showed significantly elevated proinflammatory cytokines compared to HV. Thiamine-treated DC patients showed significant lowering in IL-17 and increase in the IL-22 levels. In humans, a range of 79-474 mg daily of thiamine was estimated to be effective and safe as an intervention for the COVID-19 cytokine storm. A literature review showed that several neurological symptoms of COVID-19 (∼45.5% of the severe cases) occur in other viral infections and neuroinflammatory states that may also respond to thiamine treatment. Thiamine, a very safe drug even at very high doses, could be repurposed for treating the Th17 mediated IL-17 immune storm, and the subsequent neurological symptoms observed in COVID-19. Further studies using thiamine as an intervention/prevention strategy in COVID-19 patients could identify its precise anti-inflammatory role.

High-dose thiamine strategy in Wernicke-Korsakoff syndrome and related thiamine deficiency conditions associated with alcohol use disorder

Thiamine is essential for the activity of several enzymes associated with energy metabolism in humans. Chronic alcohol use is associated with deficiency of thiamine along with other vitamins through several mechanisms. Several neuropsychiatric syndromes have been associated with thiamine deficiency in the context of alcohol use disorder including Wernicke-Korsakoff syndrome, alcoholic cerebellar syndrome, alcoholic peripheral neuropathy, and possibly, Marchiafava-Bignami syndrome. High-dose thiamine replacement is suggested for these neuropsychiatric syndromes.

Wernicke's encephalopathy - from basic science to clinical practice. Part 1: Understanding the role of thiamine

Wernicke's encephalopathy (WE) is an acute neuropsychiatric state. Untreated, WE can lead to coma or death, or progress to Korsakoff syndrome (KS) - a dementia characterized by irreversible loss of anterograde memory. Thiamine (vitamin B1) deficiency lies at the heart of this condition. Yet, our understanding of thiamine regarding prophylaxis and treatment of WE remains limited. This may contribute to the current undertreatment of WE in clinical practice. The overall aim of this review is to identify the best strategies for prophylaxis and treatment of WE in regard to (a) dose of thiamine, (b) mode of administration, (c) timing of switch from one mode of administration to another, (d) duration of administration, and (e) use of magnesium along thiamine as an essential cofactor. Evidence from randomized controlled trials and other intervention studies is virtually absent. Therefore, we have to resort to basic science for proof of principle instead. Here, we present the first part of our clinical review, in which we explore the physiology of thiamine and the pathophysiology of thiamine deficiency. We first explore both of these in their historical context. We then review the pharmacodynamics and pharmacokinetics of thiamine, exploring the roles of the six currently known thiamine compounds, their transporters, and target enzymes. We also explore the significance of magnesium as a cofactor in thiamine-facilitated enzymatic reactions and thiamine transport. In the second (forthcoming) part of this review, we will use the findings of the current review to make evidence-based inferences about strategies for prophylaxis and treatment of WE.

Thiamine deficiency disorders: a clinical perspective

Thiamine is an essential water‐soluble vitamin that plays an important role in energy metabolism. Thiamine deficiency presents many challenges to clinicians, in part due to the broad clinical spectrum, referred to as thiamine deficiency disorders (TDDs), affecting the metabolic, neurologic, cardiovascular, respiratory, gastrointestinal, and musculoskeletal systems. Concurrent illnesses and overlapping signs and symptoms with other disorders can further complicate this. As such, TDDs are frequently misdiagnosed and treatment opportunities missed, with fatal consequences or permanent neurologic sequelae. In the absence of specific diagnostic tests, a low threshold of clinical suspicion and early therapeutic thiamine is currently the best approach. Even in severe cases, rapid clinical improvement can occur within hours or days, with neurological involvement possibly requiring higher doses and a longer recovery time. Active research aims to help better identify patients with thiamine‐responsive disorders and future research is needed to determine effective dosing regimens for the various clinical presentations of TDDs. Understanding the clinical diagnosis and global burden of thiamine deficiency will help to implement national surveillance and population‐level prevention programs, with education to sensitize clinicians to TDDs. With concerted effort, the morbidity and mortality related to thiamine deficiency can be reduced.

Alpha-lipoic acid alters the antitumor effect of bortezomib in melanoma cells in vitro

Bortezomib (BOZ) is a proteasome inhibitor chemotherapeutic agent utilized to treat multiple myeloma and recently offered to cure melanoma. Bortezomib-induced neuropathy is one of the dose-limiting side-effects, which can be treated with antioxidants (e.g. alpha-lipoic acid-ALA and Vitamin B1-vit B1). We hypothesized that these antioxidants may counteract the antitumor activity by disrupting the BOZ-induced pathways (e.g. proteasome inhibition or reactive oxygen species generation). The objectives were: (i) to verify the anti-proliferative effect of BOZ; (ii) to compare the influence of the antioxidants on the antitumor effect of BOZ in melanoma (A2058) and myeloma (U266) cells. At first, the reduction in the anti-proliferative effect of BOZ by ALA was proved in melanoma cells. Analysis of p53 phosphorylation and the cell cycle progression revealed that ALA failed to counteract these effects of BOZ. Nevertheless, a good correlation was found between the inhibition of the anti-proliferative effect, the anti-proteasome activity and the oxidative stress level after the co-treatment with 20 ng/mL BOZ + 100 μg/mL ALA. Downregulation of apoptotic proteins such as HO-1 and Claspin along with the inhibition of the cleavage of Caspase-3 indicated the proteomic background of the altered responsiveness of the melanoma cells exposed to BOZ + ALA. This phenomenon draws attention to the proper application of cancer supportive care to avoid possible interactions.

Therapeutic Prospects for Th-17 Cell Immune Storm Syndrome and Neurological Symptoms in COVID-19: Thiamine Efficacy and Safety, In-vitro Evidence and Pharmacokinetic Profile

Introduction Emerging infectious diseases, especially the coronavirus disease identified in 2019 (COVID-19), can be complicated by a severe exacerbation in the Th17 cell-mediated IL-17 proinflammatory immune storm. This enhanced immune response plays a major role in mortality and morbidity, including neurological symptoms. We hypothesized that countering the cytokine storm with thiamine may have therapeutic efficacy in lowering the Th17 cell proinflammatory response. We used an in vitro study and corroborated those results in disease controls (DC). We developed an effective dose range and model for key pharmacokinetic measures with the potential of targeting the cytokine storm and neurological symptoms of COVID-19. Study Participants and Methods We investigated the effect of a three-week 200 mg dose of thiamine in lowering the Th17 response in sixteen DC (proinflammatory origin due to heavy alcohol drinking) patients; and eight healthy control/volunteers (HV) as a pilot clinical-translational investigation. To further investigate, we performed an in vitro study evaluating the effectiveness of thiamine treatment in lowering the Th17 proinflammatory response in a mouse macrophage cell line (RAW264.7) treated with ethanol. In this in vitro study, 100 mg/day equivalent (0.01 ug/ml) thiamine was used. Based on recent publications, we compared the results of the IL-17 response from our clinical and in vitro study to those found in other proinflammatory disease conditions (metabolic conditions, septic shock, viral infections and COVID-19), including symptoms, and dose ranges of effective and safe administration of thiamine. We developed a dose range and pharmacokinetic profile for thiamine as a novel intervention strategy in COVID-19 to alleviate the effects of the cytokine storm and neurological symptoms. Results The DC group showed significantly elevated proinflammatory cytokines compared to HV. Three-week of 200 mg daily thiamine treatment significantly lowered the baseline IL-17 levels while increased IL-22 levels (anti-inflammatory response). This was validated by an in vitro macrophage response using a lower thiamine dose equivalent (100 mg), which resulted in attenuation of IL-17 and elevation of IL-22 at the mRNA level compared to the ethanol-only treated group. In humans, a range of 79-474 mg daily of thiamine was estimated to be effective and safe as an intervention for the COVID-19 cytokine storm. A literature review showed that several neurological symptoms of COVID-19 (which exist in 45.5% of the severe cases) occur in other viral infections and neuroinflammatory states that may also respond to thiamine treatment. Discussion The Th17 mediated IL-17 proinflammatory response can potentially be attenuated by thiamine. Thiamine, a very safe drug even at very high doses, could be repurposed for treating the cytokine/immune storm of COVID-19 and the subsequent neurological symptoms observed in COVID-19 patients. Further studies using thiamine as an interventional/prevention strategy in severe COVID-19 patients could identify its precise anti-inflammatory role.

Development and Characterization of Inkjet Printed Edible Films for Buccal Delivery of B-Complex Vitamins

Buccal films containing two vitamins, i.e., thiamine hydrochloride (THCl) and nicotinic acid (NA), were fabricated via two-dimensional (2D) inkjet printing. For the preparation of buccal films, solubility studies and rheological evaluations were conducted in distilled water and propylene-glycol (PG) as main solvent and viscosity/surface tension modifier, respectively. The increased solubility in the solvents' mixture indicated that manufacturing of several doses of the THCl and NA is achievable. Various doses were deposited onto sugar-sheet substrates, by increasing the number of printing passes. The physiochemical characterization (SEM, DSC, FTIR) revealed that inkjet printing does not affect the solid state of the matrix. Water uptake studies were conducted, to compare the different vitamin-loaded formulations. The in vitro release studies indicated the burst release of both vitamins within 10 min, a preferable feature for buccal administration. The in vitro permeation studies indicated that higher concentrations of the vitamins onto the sugar sheet improved the in vitro permeation performance of printed formulations.

Does the Affinity of Cisplatin to B-Vitamins Impair the Therapeutic Effect in the Case of Patients with Lung Cancer-consuming Carrot or Beet Juice?

BACKGROUND

Cisplatin (CisPt) has a well-recognized anticancer activity by interacting with DNA and inducing programmed cell death. However, theoretical studies performed on the molecular level suggest that such nonspecific interactions can also take place with many competitive compounds, such as vitamins containing aromatic rings with lone-pair orbitals.

OBJECTIVE

This work is a theoretical study on the initial Pt-N₇(N₁) bond formation with vitamins from B group and their comparison with values characterizing native purines.

METHODS

Geometries of studied structures were optimized with an aid of Gaussian 09 using the B3LYP functional with the 6-31G** basis set. Atomic orbitals of platinum were represented by the lanl2dz basis. Solvation free energies were evaluated by a self-consistent reaction field (SCRF) approach. A dielectric constant of 78 for water was used in the PCM continuum model computations along with radii Bondii.

RESULTS

The affinities of mono-aqua cis~[Pt(NH₃)₂Cl(H₂O)]+ and di-aqua cis~ [Pt(NH₃)₂(H₂O)₂]²⁺ derivatives of Cisplatinum toward compounds belonging to the group of eight B vitamins were studied and compared to interactions with canonical purines. All the values of ΔGr unambiguously indicate that reactions with cisPt-diaqua are more preferable, but the comparison of ΔGr values obtained for compounds from vitamin B group and the ones characterizing complexes created by Guanine molecules indicates higher affinity of cisPt monomers toward purines.

CONCLUSION

Based on the observations, the regular intake of vitamin-rich beetroot or carrot juices is strongly discouraged during anticancer therapy using CisPt drug. To confirm the results of the performed computational study, detailed clinical trials should be performed.

Association Between IV Thiamine and Mortality in Patients With Septic Shock: A Nationwide Observational Study

OBJECTIVES

To examine the effect of thiamine administration on mortality in patients with septic shock requiring norepinephrine.

DESIGN

Retrospective observational cohort study from July 2010 to March 2017.

SETTING

More than 1,000 acute care hospitals covering approximately 90% of all tertiary care emergency hospitals in Japan.

PATIENTS

Patients with septic shock requiring norepinephrine within 2 days of admission were retrospectively reviewed.

INTERVENTIONS

Patients who received greater than or equal to 100 mg of thiamine within 2 days of admission were included in the thiamine group and those who did not were included in the control group.

MEASUREMENTS AND MAIN RESULTS

We identified a total of 68,571 eligible patients, including 18,780 and 49,791 patients in the thiamine and control groups, respectively. In the thiamine group, 100 and 200 mg of thiamine per day were administered to 10,143 (54.0%) and 7,679 (40.9%) patients, respectively. The 28-day mortality were 19.2% (3,609/18,780) and 17.8% (8,845/49,791) in the thiamine and control groups, respectively. After adjusting for confounders by inverse probability of treatment weighting, no significant differences were observed between the two groups (risk difference, 0.2%; 95% CI, -0.5% to 0.9%). There were also no significant differences between the 100-mg thiamine group and the control group (risk difference, 0.6%; 95% CI, -0.3% to 1.4%) or between the 200-mg thiamine group and the control group (risk difference, -0.3%; 95% CI, -1.3% to 0.8%).

CONCLUSIONS

The findings of this nationwide database-based observational study did not support an association between thiamine administration early after admission and the 28-day mortality in patients with septic shock.

High-dose vitamin B supplementation for persistent visual deficit in multiple sclerosis: a pilot study

The aim of this study is to investigate the potential neuroprotective effect of high-doses vitamins B1, B6 and B12 in patients with relapsing-remitting multiple sclerosis (RRMS) and persistent visual loss after acute optic neuritis (AON). Sixteen patients (20 eyes) diagnosed with RRMS and visual permanent disability following AON were enrolled for the present open, pilot study. Each patient was treated with oral high-doses 300 mg of vitamin B1, 450 mg of vitamin B6 and 1,500 mcg of vitamin B12, as add-on treatment to concomitant disease-modifying therapies (DMTs) for consecutive 90 days. Outcome measures were to determine changes from baseline to month three in visual acuity (VA) and visual field (VF) testing, with correlations with clinical parameters. Logistical regression was performed to evaluate predictors of final VA. A statistically significant improvement was registered in visual acuity (p = 0.002) and foveal sensitivity threshold (FT) (p = 0.006) at follow-up compared to baseline. A similar trend was demonstrated for mean deviation (MD) (p < 0.0001), and pattern standard deviation (PSD) (p < 0.0001). Age at the time of inclusion was positively correlated with latency time (rho = 0.47, p = 0.03), while showing a negative correlation with visual acuity (rho = - 0.45, p = 0.04) and foveal sensitivity threshold (rho = - 0.6, p = 0.005) at follow up. A statistically significant correlation was demonstrated between foveal sensitivity threshold and visual acuity at baseline (rho = 0.79, p < 0.0001). In a linear regression model, the main predictor of visual acuity at follow up was the foveal sensitivity threshold (B = 1.39; p < 0.0001). Supplemental high-dose vitamins B1, B6 and B12 resulted as effective therapy to improve visual function parameters in MS-related visual persistent disability.

Effect of Combined Diclofenac and B Vitamins (Thiamine, Pyridoxine, and Cyanocobalamin) for Low Back Pain Management: Systematic Review and Meta-analysis

BACKGROUND

Cumulative evidence suggests an analgesic effect of thiamine, pyridoxine, and cyanocobalamin (TPC) in monotherapy, and also when combined with nonsteroidal anti-inflammatory drugs (NSAIDs), particularly diclofenac, in a synergistic manner. The aim of this review was to determine the effects of diclofenac combined with TPC compared with diclofenac monotherapy for low back pain (LBP) management.

METHODS

We searched for randomized clinical trials on the MEDLINE, EMBASE, LILACS, and Cochrane databases of records of clinical trials, among other sources. We evaluated the risk of bias regarding randomization, allocation concealment, blinding, incomplete outcome data, selective reporting, and other biases. A random-effects meta-analysis to examine patients with acute LBP (N = 1,108 adults) was performed, along with a subsequent sensitivity analysis.

RESULTS

Five studies in patients with LBP were included in the qualitative synthesis. Four of these studies in acute LBP were included in the first meta-analysis. A sensitivity test based on risk of bias (three moderate- to high-quality studies) found that the combination therapy of diclofenac plus TPC was associated with a significant reduction in the duration of treatment (around 50%) compared with diclofenac monotherapy (odds ratio = 2.23, 95% confidence interval = 1.59 to 3.13, P < 0.00001). We found no differences in the safety profile and patient satisfaction.

CONCLUSIONS

This meta-analysis demonstrated that combination therapy of diclofenac with TPC might have an analgesic superiority compared with diclofenac monotherapy in acute LBP. However, there is not enough evidence to recommend this therapy in other types of pain due to the scarcity of high-quality studies.

Thiamine transporter 2 is involved in high glucose-induced damage and altered thiamine availability in cell models of diabetic retinopathy

Thiamine prevents high glucose-induced damage in microvasculature, and progression of retinopathy and nephropathy in diabetic animals. Impaired thiamine availability causes renal damage in diabetic patients. Two single-nucleotide polymorphisms in SLC19A3 locus encoding for thiamine transporter 2 are associated with absent/minimal diabetic retinopathy and nephropathy despite long-term type 1 diabetes. We investigated the involvement of thiamine transporter 1 and thiamine transporter 2, and their transcription factor specificity protein 1, in high glucose-induced damage and altered thiamine availability in cells of the inner blood-retinal barrier. Human endothelial cells, pericytes and Müller cells were exposed to hyperglycaemic-like conditions and/or thiamine deficiency/over-supplementation in single/co-cultures. Expression and localization of thiamine transporter 1, thiamine transporter 2 and transcription factor specificity protein 1 were evaluated together with intracellular thiamine concentration, transketolase activity and permeability to thiamine. The effects of thiamine depletion on cell function (viability, apoptosis and migration) were also addressed. Thiamine transporter 2 and transcription factor specificity protein 1 expression were modulated by hyperglycaemic-like conditions. Transketolase activity, intracellular thiamine and permeability to thiamine were decreased in cells cultured in thiamine deficiency, and in pericytes in hyperglycaemic-like conditions. Thiamine depletion reduced cell viability and proliferation, while thiamine over-supplementation compensated for thiamine transporter 2 reduction by restoring thiamine uptake and transketolase activity. High glucose and reduced thiamine determine impairment in thiamine transport inside retinal cells and through the inner blood-retinal barrier. Thiamine transporter 2 modulation in our cell models suggests its major role in thiamine transport in retinal cells and its involvement in high glucose-induced damage and impaired thiamine availability.

Comparison of the Acute Postprandial Circulating B-Vitamin and Vitamer Responses to Single Breakfast Meals in Young and Older Individuals: Preliminary Secondary Outcomes of a Randomized Controlled Trial

B-vitamin deficiency is common in ageing populations either due to altered dietary habits or altered digestive and metabolic functions. There is limited data on the acute circulating concentrations of B-vitamins and their various forms (vitamers), following ingestion of realistic meals. This study compared the acute circulating B-vitamin and vitamer responses to either an energy-dense (ED) or a nutrient-dense (ND) breakfast meal, consumed in a randomized cross-over sequence, in older and younger adults (n = 15 and 15, aged 67.3 ± 1.5 and 22.7 ± 0.5 years (mean ± SEM), respectively). Eleven differing B-vitamins and vitamers were determined in plasma samples by ultra-high-performance liquid chromatography-tandem mass spectrometry, in the fasting and postprandial state (hourly for 5 h). While postprandial thiamine concentration increased following both meals, riboflavin increased only following a ND meal in both age groups. Many vitamins including nicotinic acid, pantothenic acid, pyridoxal, pyridoxamine, pyridoxal-5'phosphate, and 4-pyridoxic acid remained unaltered, and flavin mononucleotide (FMN), nicotinamide and nicotinuric acid concentrations reduced following both meals. Biological age and food composition had minimal impact on postprandial B-vitamin concentrations, yet the differences between the ED and ND meals for riboflavin highlight the importance of riboflavin intake to achieve adequacy.

Thiamine mimetics sulbutiamine and benfotiamine as a nutraceutical approach to anticancer therapy

Malignant cells frequently demonstrate an oncogenic-driven reliance on glycolytic metabolism to support their highly proliferative nature. Overexpression of pyruvate dehydrogenase kinase (PDK) may promote this unique metabolic signature of tumor cells by inhibiting mitochondrial function. PDKs function to phosphorylate and inhibit pyruvate dehydrogenase (PDH) activity. Silencing of PDK expression has previously been shown to restore mitochondrial function and reduce tumor cell proliferation. High dose Vitamin B1, or thiamine, possesses antitumor properties related to its capacity to reduce PDH phosphorylation and promote its enzymatic activity, presumably through PDK inhibition. Though a promising nutraceutical approach for cancer therapy, thiamine's low bioavailability may limit clinical effectiveness. Here, we have demonstrated exploiting the commercially available lipophilic thiamine analogs sulbutiamine and benfotiamine increases thiamine's anti-cancer effect in vitro. Determined by crystal violet proliferation assays, both sulbutiamine and benfotiamine reduced thiamine's millimolar IC50 value to micromolar equivalents. HPLC analysis revealed that sulbutiamine and benfotiamine significantly increased intracellular thiamine and TPP concentrations in vitro, corresponding with reduced levels of PDH phosphorylation. Through an ex vitro kinase screen, thiamine's activated cofactor form thiamine pyrophosphate (TPP) was found to inhibit the function of multiple PDK isoforms. Attempts to maximize intracellular TPP by exploiting thiamine homeostasis gene expression resulted in enhanced apoptosis in tumor cells. Based on our in vitro evaluations, we conclude that TPP serves as the active species mediating thiamine's inhibitory effect on tumor cell proliferation. Pharmacologic administration of benfotiamine, but not sulbutiamine, reduced tumor growth in a subcutaneous xenograft mouse model. It remains unclear if benfotiamine's effects in vivo are associated with PDK inhibition or through an alternative mechanism of action. Future work will aim to define the action of lipophilic thiamine mimetics in vivo in order to translate their clinical usefulness as anticancer strategies.

Variability and Heritability of Thiamine Pharmacokinetics With Focus on OCT1 Effects on Membrane Transport and Pharmacokinetics in Humans

Thiamine is substrate of the hepatic uptake transporter organic cation transporter 1 (OCT1), and pathological lipid metabolism was associated with OCT1-dependent thiamine transport. However, it is unknown whether clinical pharmacokinetics of thiamine is modulated by OCT1 genotype. We analyzed thiamine transport in vitro, thiamine blood concentrations after high-dose and low-dose (nutritional) intake, and heritability of thiamine and thiamine-phosphate blood concentrations. The variant OCT1*2 had reduced and OCT1*3 to OCT1*6 had deficient thiamine uptake activity. However, pharmacokinetics of thiamine did not differ depending on OCT1 genotype. Further studies in primary human hepatocytes indicated that several cation transporters, including OCT1, OCT3, and THTR-2, contribute to hepatic uptake of thiamine. As much as 54% of the variation in thiamine and 75% in variation of thiamine monophosphate plasma concentrations was determined by heritable factors. Apparently, thiamine is not useful as a probe drug for OCT1 activity, but the high heritability, particularly of thiamine monophosphate, may stimulate further genomic research.

Alteration in MDA, GSH level and hematological changes due to thiamine deficiency in Mus musculus

It is known that thiamine deficiency may lead to Alzheimer’s diseases in humans. The present study has thus been conducted to understand the role of thiamine deficiency with respect to alteration in the peripheral blood of Swiss albino mice. For this purpose, adult Swiss albino mice (6–8 week old) were divided into three groups. The first group was control; the second (group II) and the third group (group III) were made thiamine deficient for 08 and 10 days respectively. Thiamine deficiency was induced in mice by injecting pyrithiamine (5 µg/10 g bwt) and feeding a thiamine deficient diet. The erythrocytes, leukocytes count, hemoglobin, hematocrit value, mass cell volume, mean corpuscular hemoglobin in blood of mice were determined by hematoanalyzer. Malondialdehyde (MDA) and reduced glutathione (GSH) level was also determined in serum of treated and non-treated groups. A significant reduction in leukocyte and erythrocyte count was observed in both the thiamine deficient groups as compared to control. Levels of hemoglobin and hematocrit value were also declined in the thiamine deficient groups. Enhancement in mass cell volume (MCV) level and decline in mean corpuscular hemoglobin (MCH) levels were observed in both thiamine deficient groups with respect to control. Inter-group comparison of all parameters also showed a significant value at p<0.01. In comparison with the control group, elevation in MDA and decline in GSH level was observed in both thiamine deficient groups which were statistically significant. These data indicate that thiamine deficiency leads to significant alterations in the hematological parameters as well as in MDA and GSH level.

Thiamine dose response in human milk with supplementation among lactating women in Cambodia: study protocol for a double-blind, four-parallel arm randomised controlled trial

INTRODUCTION

Thiamine (vitamin B1) deficiency remains a concern in Cambodia where women with low thiamine intake produce thiamine-poor milk, putting their breastfed infants at risk of impaired cognitive development and potentially fatal infantile beriberi. Thiamine fortification of salt is a potentially low-cost, passive means of combating thiamine deficiency; however, both the dose of thiamine required to optimise milk thiamine concentrations as well as usual salt intake of lactating women are unknown.

METHODS AND ANALYSIS

In this community-based randomised controlled trial, 320 lactating women from Kampong Thom, Cambodia will be randomised to one of four groups to consume one capsule daily containing 0, 1.2, 2.4 or 10 mg thiamine as thiamine hydrochloride, between 2 and 24 weeks postnatal. The primary objective is to estimate the dose where additional maternal intake of thiamine no longer meaningfully increases infant thiamine diphosphate concentrations 24 weeks postnatally. At 2, 12 and 24 weeks, we will collect sociodemographic, nutrition and health information, a battery of cognitive assessments, maternal (2 and 24 weeks) and infant (24 weeks only) venous blood samples (biomarkers: ThDP and transketolase activity) and human milk samples (also at 4 weeks; biomarker: milk thiamine concentrations). All participants and their families will consume study-provided salt ad libitum throughout the trial, and we will measure salt disappearance each fortnight. Repeat weighed salt intakes and urinary sodium concentrations will be measured among a subset of 100 participants. Parameters of Emax dose-response curves will be estimated using non-linear least squares models with both 'intention to treat' and a secondary 'per-protocol' (capsule compliance ≥80%) analyses.

ETHICS AND DISSEMINATION

Ethical approval was obtained in Cambodia (National Ethics Committee for Health Research 112/250NECHR), Canada (Mount Saint Vincent University Research Ethics Board 2017-141) and the USA (University of Oregon Institutional Review Board 07052018.008). Results will be shared with participants' communities, as well as relevant government and scientific stakeholders via presentations, academic manuscripts and consultations.

TRIAL REGISTRATION NUMBER

NCT03616288.

Supplemental thiamine for the treatment of acute heart failure syndrome: a randomized controlled trial

Background

The purpose of this pilot study was to determine if a definitive clinical trial of thiamine supplementation was warranted in patients with acute heart failure. We hypothesized that thiamine, when added to standard of care, would improve dyspnea (primary outcome) in hospitalized patients with acute heart failure. Peak expiratory flow rate, type B natriuretic peptide, free fatty acids, glucose, hospital length of stay, as well as 30-day rehospitalization and mortality were pre-planned secondary outcome measures.

Methods

This was a blinded experimental study at two urban academic hospitals. Consecutive patients admitted from the Emergency Department with a primary diagnosis of acute heart failure were recruited over 2 years. Patients on a daily dietary supplement were excluded. Randomization was stratified by type B natriuretic peptide and diabetes medication categories. Subjects received study drug (100 mg thiamine or placebo) in the evening of their first and second day. Outcome measures were obtained 8 h after study drug infusion. Dyspnea was measured on a 100-mm visual analog scale sitting up on oxygen, sitting up off oxygen, and lying supine off oxygen with 0 indicating no dyspnea. Data were analyzed using mixed-models as well as linear, negative binomial and logistic regression models to assess the impact of group on outcome measures.

Results

Of 130 subjects randomized, 118 had evaluable data (55 in the control and 63 in the treatment groups), 89% in both groups were adjudicated to have primarily AHF. Thiamine values increased significantly in the treatment group and were unchanged in the control group. One patient had thiamine deficiency. Only dyspnea measured sitting upright on oxygen differed significantly by group over time. No change was found for the other measures of dyspnea and all of the secondary measures.

Conclusions

In mild-moderate acute heart failure patients without thiamine deficiency, a standard dosing regimen of thiamine did not improve dyspnea, biomarkers, or other clinical parameters.

Trial registration

ClinicalTrials.gov: NCT00680706, May 20, 2008 (retrospectively registered).

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2506-8) contains supplementary material, which is available to authorized users.

Review of thiamine deficiency disorders: Wernicke encephalopathy and Korsakoff psychosis

Wernicke encephalopathy (WE) and Korsakoff psychosis (KP), together termed Wernicke-Korsakoff syndrome (WKS), are distinct yet overlapping neuropsychiatric disorders associated with thiamine deficiency. Thiamine pyrophosphate, the biologically active form of thiamine, is essential for multiple biochemical pathways involved in carbohydrate utilization. Both genetic susceptibilities and acquired deficiencies as a result of alcoholic and non-alcoholic factors are associated with thiamine deficiency or its impaired utilization. WKS is underdiagnosed because of the inconsistent clinical presentation and overlapping of symptoms with other neurological conditions. The identification and individualized treatment of WE based on the etiology is vital to prevent the development of the amnestic state associated with KP in genetically predisposed individuals. Through this review, we bring together the existing data from animal and human models to expound the etiopathogenesis, diagnosis, and therapeutic interventions for WE and KP.

The Effects of Thiamine Tetrahydrofurfuryl Disulfide on Physiological Adaption and Exercise Performance Improvement

Thiamine, named as vitamin B1, is an important cofactor for the critical enzymes regarding to glucose metabolism, like transketolase, pyruvate dehydrogenase, and alpha-ketoglutarate dehydrogenase. The thiamine tetrahydrofurfuryl disulfide (TTFD) is a derivative of thiamine with higher bioavailability and solubility than thiamine and has been widely applied to health maintenance and disease therapy. Higher physical activities are associated with higher thiamine supplements for efficient energy metabolism. Furthermore, the effective dose of TTFD, beneficial to exercise physiological adaption and performance, still be further validated and the safety evaluation were also an important issue to be considered for potential application. ICR (Institute of Cancer Research) strain mice were allocated as 0, 50, 100, and 500 mg/kg dose groups and administrated by oral gavage consecutively for 6 weeks. Physical activities including grip strength and aerobic endurance were measured. Various fatigue-associated biochemical variables such as lactate, glucose, blood urine nitrogen (BUN) or creatine kinase (CK), were also assessed. The levels of liver and muscle glycogen were measured as an indicator of energy storage at the end of the experiment. Toxicity assessments for long-term supplementation were also further evaluated for safety consideration. TTFD supplementation significantly increased the endurance and grip strength and demonstrated beneficial effects on lactate production and clearance rate after an acute exercise challenge. The TTFD supplementation significantly mitigated the BUN and CK indexes after extended exercise and elevated the glycogen content in the liver and muscle tissues. According to body composition, biochemical and histopathological data, daily administration of TTFD for over 6 weeks (subacute toxicity) also demonstrated reasonable safety results for long-term and adequate supplementation. The toxicity of TTFD were also considered as safety for long-term supplementation with indicated doses. Furthermore, the TTDF could be applied to not only the health promotion but also improvement of exercise physiological adaption and the TTFD could be further considered as potential ergogenic aids combined with different nutrient strategy.

Oral High-Dose Thiamine Improves the Symptoms of Chronic Cluster Headache

Cluster headache is a rare painful primary disorder occurring in either episodic or chronic patterns. Several authors found that the hypothalamus, the brain region regulating endocrine function and autonomic system, is involved in the pathophysiology of cluster headache. Some authors have found in patients affected by this disease abnormality in glucose metabolism. Considering the role of thiamine in brain function, in energetic metabolism, and in pain modulation, we treated a patient affected by cluster headache with oral high-dose thiamine. We report a 41-year-old man suffering from primary chronic cluster headache since the age of 15 years. The patient began oral therapy with high-dose thiamine in December 2016. Oral thiamine supplementation led to a dramatic improvement of the symptoms. The therapy was effective in reversing all the symptoms of the disease. Our observation suggests that a thiamine deficiency due to enzymatic abnormalities or to dysfunction of the circulation of thiamine in the intracellular space could cause a neuronal selective impairment in the centers that are involved in this disease and could have an important role in the pathogenesis of the symptoms of cluster headache.

High-dose thiamine and essential tremor

Essential tremor is a common neurological disease. The medical treatment of this affection currently involves the use of propranolol, primidone and other drugs. These drugs, however, are often not effective in reducing tremor and cause side effects in a large share of the patients treated. The treatment with intramuscular high-dose thiamine has led to a rapid, remarkable and persistent improvement of the symptoms in two patients with essential tremor. This result suggests the possibility that high doses of intramuscular thiamine may be an affordable alternative, highly effective and long-lasting medical treatment that has shown no relevant side effect.

Alcohol-related cognitive impairment: current trends and future perspectives

Excessive alcohol use is associated with a wide range of physical, psychological and social consequences, and is responsible for a significant proportion of the burden of disease globally. An area which has received increasing interest is alcohol-related brain damage, not just because of the cost to the individual and society through resource utilization, but also because of the potential for prevention and reversibility. This paper aims to review the current literature on this subject and seeks to explore issues around diagnosis and treatment of alcohol-related brain damage.

Comparative Pharmacokinetic Analysis of Thiamine and Its Phosphorylated Metabolites Administered as Multivitamin Preparations

PURPOSE

Fursultiamine and benfotiamine are lipophilic thiamine derivatives used as oral sources of thiamine. Although there are many publications on the pharmacokinetic (PK) properties of thiamine-containing products, no direct comparisons between these agents . We aimed to compare the PK profiles of these lipophilic thiamine derivatives and to compare the extent of the increase in bioavailability to that of naïve thiamine.

METHODS

Two randomized, single-dose, 2-way crossover, full PK studies were conducted in healthy Korean male subjects (n = 24 per group). Among the test compounds, fursultiamine was compared with benfotiamine (reference A in study A) and thiamine nitrate (reference B in study B). All formulations were multivitamin preparations containing the test or reference formulation as the major thiamine source. In study A, the plasma and hemolysate concentrations of thiamine and its metabolites were measured, while only the plasma thiamine concentration was assayed in study B.

FINDINGS

The systemic thiamine exposure of the test compound was slightly greater than that of reference A, based on the geometric mean ratio (%) of the AUC_last value for plasma (116.6%) and hemolysate (137.5%). The thiamine diphosphate (TDP) distribution between plasma and hemolysate showed clear differences according to the formulations, in that more TDP was present in the hemolysate when thiamine was given as the test formulation. The AUC_last value of plasma thiamine showed a >300% increase when thiamine was given as the test formulation in study B. The summed total exposure to thiamine (thiamine + TDP in both plasma and hemolysate) observed as a point estimate after the administration of fursultiamine was slightly greater than that with benfotiamine; however, the 90% CI was within the conventional bioequivalence range.

IMPLICATIONS

These findings support clear benefits of lipophilic thiamine derivatives in the absorption of thiamine in healthy volunteers. Clinical Research Information Service identifiers: KCT0001419 (study A), KCT0001628 (study B).

Long-term treatment with thiamine as possible medical therapy for Friedreich ataxia

Thiamine (vitamin B1) is a cofactor of fundamental enzymes of cell energetic metabolism; its deficiency causes disorders affecting both the peripheral and central nervous system. Previous studies reported low thiamine levels in cerebrospinal fluid and pyruvate dehydrogenase dysfunction in Friedreich ataxia (FRDA). We investigated the effect of long-term treatment with thiamine in FRDA, evaluating changes in neurological symptoms, echocardiographic parameters, and plasma FXN mRNA levels. Thirty-four consecutive FRDA patients have been continuously treated with intramuscular thiamine 100 mg twice a week and have been assessed with the Scale for the Assessment and Rating of Ataxia (SARA) at baseline, after 1 month, and then every 3 months during treatment. Thiamine administration ranged from 80 to 930 days and was effective in improving total SARA scores from 26.6 ± 7.7 to 21.5 ± 6.2 (p < 0.02). Moreover, deep tendon reflexes reappeared in 57 % of patients with areflexia at baseline, and swallowing improved in 63 % of dysphagic patients. Clinical improvement was stable in all patients, who did not show worsening even after 2 years of treatment. In a subgroup of 13 patients who performed echocardiogram before and during treatment, interventricular septum thickness reduced significantly (p < 0.02). Frataxin mRNA blood levels were modestly increased in one-half of treated patients. We suppose that a focal thiamine deficiency may contribute to a selective neuronal damage in the areas involved in FRDA. Further studies are mandatory to evaluate thiamine role on FXN regulation, to exclude placebo effect, to verify our clinical results, and to confirm restorative and neuroprotective action of thiamine in FRDA.

Thiamine Deficiency in Tropical Pediatrics: New Insights into a Neglected but Vital Metabolic Challenge

In humans, thiamine is a micronutrient prone to depletion that may result in severe clinical abnormalities. This narrative review summarizes current knowledge on thiamine deficiency (TD) and bridges the gap between pathophysiology and clinical presentation by integrating thiamine metabolism at subcellular level with its function to vital organs. The broad clinical spectrum of TD is outlined, with emphasis on conditions encountered in tropical pediatric practice. In particular, TD is associated with type B lactic acidosis and classic forms of beriberi in children, but it is often unrecognized. Other severe acute conditions are associated with hypermetabolism, inducing a functional TD. The crucial role of thiamine in infant cognitive development is also highlighted in this review, along with analysis of the potential impact of TD in refeeding syndrome during severe acute malnutrition (SAM). This review aims to increase clinical awareness of TD in tropical settings where access to diagnostic tests is poor, and advocates for an early therapeutic thiamine challenge in resource-limited settings. Moreover, it provides evidence for thiamine as treatment in critical conditions requiring metabolic resuscitation, and gives rationale to the consideration of increased thiamine supplementation in therapeutic foods for malnourished children.

Pharmacokinetics of the transdermal delivery of benfotiamine

AIMS

Accumulation of advanced glycation endpoints is a trigger to the development of diabetic peripheral neuropathy, which is a common complication of diabetes. Oral administration of benfotiamine (BFT) has shown some preclinical and clinical promise as a treatment for diabetic peripheral neuropathy. The purpose of this study was to evaluate the method of transdermal delivery of BFT as a possible, viable route of administration for the treatment of diabetic peripheral neuropathy.

METHODS

A single application of 10 mg of BFT was given to guinea pigs topically. The levels of thiamine (T), thiamine monophosphate, thiamine diphosphate, S-benzoylthiamine and BFT were measured in the blood, skin and muscle at different time points within 24 h.

RESULTS

At the 24-h time point, following the single BFT dose, the T level was increased 10× in the blood, more than 7× in the skin and almost 4× in the muscle compared to the untreated animals. The total T content (total) was increased 7× in the blood, 17× in the skin and 3× in the muscle compared to the untreated animals.

CONCLUSIONS

This strong increase in the tissue levels of T and the associated metabolic derivatives levels found in the blood and local tissues following a single dose indicate that topically applied BFT may be a viable and advantageous delivery method for the treatment of diabetic peripheral neuropathy.

B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review

The B-vitamins comprise a group of eight water soluble vitamins that perform essential, closely inter-related roles in cellular functioning, acting as co-enzymes in a vast array of catabolic and anabolic enzymatic reactions. Their collective effects are particularly prevalent to numerous aspects of brain function, including energy production, DNA/RNA synthesis/repair, genomic and non-genomic methylation, and the synthesis of numerous neurochemicals and signaling molecules. However, human epidemiological and controlled trial investigations, and the resultant scientific commentary, have focused almost exclusively on the small sub-set of vitamins (B9/B12/B6) that are the most prominent (but not the exclusive) B-vitamins involved in homocysteine metabolism. Scant regard has been paid to the other B vitamins. This review describes the closely inter-related functions of the eight B-vitamins and marshals evidence suggesting that adequate levels of all members of this group of micronutrients are essential for optimal physiological and neurological functioning. Furthermore, evidence from human research clearly shows both that a significant proportion of the populations of developed countries suffer from deficiencies or insufficiencies in one or more of this group of vitamins, and that, in the absence of an optimal diet, administration of the entire B-vitamin group, rather than a small sub-set, at doses greatly in excess of the current governmental recommendations, would be a rational approach for preserving brain health.

Can long-term thiamine treatment improve the clinical outcomes of myotonic dystrophy type 1?

Myotonic dystrophy type 1, also known as Steinert's disease, is an autosomal dominant disorder with multisystemic clinical features affecting the skeletal and cardiac muscles, the eyes, and the endocrine system. Thiamine (vitamin B1) is a cofactor of fundamental enzymes involved in the energetic cell metabolism; recent studies described its role in oxidative stress, protein processing, peroxisomal function, and gene expression. Thiamine deficiency is critical mainly in the central and peripheral nervous system, as well as in the muscular cells. Our aim was to investigate the potential therapeutical effects of long-term treatment with thiamine in myotonic dystrophy type 1 in an observational open-label pilot study. We described two patients with myotonic dystrophy type 1 treated with intramuscular thiamine 100 mg twice a week for 12 or 11 months. We evaluated the patients using the grading of muscle strength according to Medical Research Council (MRC), the Muscular Impairment Rating Scale (MIRS), and the Modified Barthel index. High-dose thiamine treatment was well tolerated and effective in improving the motor symptomatology, particularly the muscle strength evaluated with the MRC scale, and the patients' activities of daily living using the Modified Barthel Index. At the end of treatment, the MRC score was 5 in the proximal muscles and 2-4 in the distal muscles (the MRC score before the treatment was 3-4 and 1-3, respectively). The MIRS grade improved by 25% compared to baseline for both patients. In patient #1, the Modified Barthel Index improved by 44%, and in patient #2 by 29%. These findings suggest that clinical outcomes are improved by long-term thiamine treatment.

Long-Term Treatment with High-Dose Thiamine in Parkinson Disease: An Open-Label Pilot Study

OBJECTIVES

To investigate the potential clinical, restorative, and neuroprotective effects of long-term treatment with thiamine in Parkinson disease (PD).

DESIGN

Observational open-label pilot study.

SETTING

Outpatient neurologic rehabilitation clinic.

PATIENTS AND METHODS

Starting in June 2012, we have recruited 50 patients with PD (33 men and 17 women; mean age, 70.4 ± 12.9 years; mean disease duration, 7.3 ± 6.7 years). All the patients were assessed at baseline with the Unified Parkinson's Disease Rating Scale (UPDRS) and the Fatigue Severity Scale (FSS) and began treatment with 100 mg of thiamine administered intramuscularly twice a week, without any change to personal therapy. All the patients were re-evaluated after 1 month and then every 3 months during treatment.

RESULTS

Thiamine treatment led to significant improvement of motor and nonmotor symptoms: mean UPDRS scores (parts I-IV) improved from 38.55 ± 15.24 to 18.16 ± 15.08 (p = 2.4 × 10(-14), t test for paired data) within 3 months and remained stable over time; motor UPDRS part III score improved from 22.01 ± 8.57 to 9.92 ± 8.66 (p = 3.1 × 10(-22)). Some patients with a milder phenotype had complete clinical recovery. FSS scores, in six patients who had fatigue, improved from 53.00 ± 8.17 to 23.60 ± 7.77 (p < 0.0001, t test for paired data). Follow-up duration ranged from 95 to 831 days (mean, 291.6 ± 207.2 days).

CONCLUSIONS

Administration of parenteral high-dose thiamine was effective in reversing PD motor and nonmotor symptoms. The clinical improvement was stable over time in all the patients. From our clinical evidence, we hypothesize that a dysfunction of thiamine-dependent metabolic processes could cause selective neural damage in the centers typically affected by this disease and might be a fundamental molecular event provoking neurodegeneration. Thiamine could have both restorative and neuroprotective action in PD.

Determining the Role of Thiamine Deficiency in Systolic Heart Failure: A Meta-Analysis and Systematic Review

BACKGROUND

Approximately 5.7 million Americans carry the diagnosis of systolic heart failure (HF), a major health care burden. HF is a known manifestation of thiamine deficiency (TD). HF patients are at unique risk for developing TD, which may contribute to further altered cardiac function and symptoms.

METHODS AND RESULTS

We performed a systematic review of the literature and a meta-analysis to evaluate the prevalence of TD in HF patients, risk factors for and mechanisms of development of TD in HF population, and outcomes of thiamine supplementation in HF patients. We found 54 studies that met our selection criteria, 9 of which were suitable for meta-analysis. TD is more common in HF patients than control subjects (odds ratio 2.53, 95% confidence interval 1.65-3.87). Diuretic use, changes in dietary habits, and altered thiamine absorption and metabolism were identified as possible mechanisms of TD in HF patients. Small observational studies and randomized control trials suggest that thiamine supplementation in HF population may improve ejection fraction and reduce symptoms.

CONCLUSIONS

Thiamine deficiency is more prevalent in the HF population, and its supplementation may be beneficial. The therapeutic role of thiamine in HF warrants further study.