Disulfiram metabolite S-methyl-N,N-diethylthiocarbamate quantitation in human plasma with reverse phase ultra performance liquid chromatography and mass spectrometry

Degradation of Amyloid-β Species by Multi-Copper Oxidases

Background

Reduction of the production of amyloid-β (Aβ) species has been intensively investigated as potential therapeutic approaches for Alzheimer's disease (AD). However, the degradation of Aβ species, another potential beneficial approach, has been far less explored.

Objective

To investigate the potential of multi-copper oxidases (MCOs) in degrading Aβ peptides and their potential benefits for AD treatment.

Methods

We investigated the degradation efficiency of MCOs by using electrophoresis and validated the ceruloplasmin (CP)-Aβ interaction using total internal reflection fluorescence microscopy, fluorescence photometer, and fluorescence polarization measurement. We also investigated the therapeutic effect of ascorbate oxidase (AO) by using induced pluripotent stem (iPS) neuron cells and electrophysiological analysis with brain slices.

Results

We discovered that CP, an important MCO in human blood, could degrade Aβ peptides. We also found that other MCOs could induce Aβ degradation as well. Remarkably, we revealed that AO had the strongest degrading effect among the tested MCOs. Using iPS neuron cells, we observed that AO could rescue neuron toxicity which induced by Aβ oligomers. In addition, our electrophysiological analysis with brain slices suggested that AO could prevent an Aβ-induced deficit in synaptic transmission in the hippocampus.

Conclusions

To the best of our knowledge, our report is the first to demonstrate that MCOs have a degrading function for peptides/proteins. Further investigations are warranted to explore the possible benefits of MCOs for future AD treatment.

Development and validation of reversed-phase-HPLC method for simultaneous quantification of fulvestrant and disulfiram in liposomes

This study aims to develop and validate an HPLC technique for the determination of fulvestrant and disulfiram in liposomes. Encapsulation of both drugs into liposomes may improve their anticancer potential. Validation was performed following the International Conference on Harmonization guidelines for specificity, linearity, limit of detection, limit of quantification, precision, accuracy and robustness. Method specificity displayed no interference and linearity over 25-200 and 12.5-100 μg/ml for fulvestrant and disulfiram, respectively. Precision and accuracy exhibited a low relative standard deviation (<1.70%) and appropriate recovery. The validated method could be designated as a proper method for the simultaneous determination of fulvestrant and disulfiram in liposomes. The liposomes displayed 148.5 ± 5.1 nm size. The encapsulation efficiencies were 73.52 and 50.50% for fulvestrant and disulfiram, respectively.

Degradation of amyloid beta species by multi-copper oxidases

Reduction of the production of amyloid beta (Aβ) species has been intensively investigated as potential therapeutic approaches for Alzheimer's disease (AD). However, the degradation of Aβ species, another potential beneficial approach, has been far less explored. In this study, we discovered that ceruloplasmin (CP), an important multi-copper oxidase (MCO) in human blood, could degrade Aβ peptides. We also found that the presence of Vitamin C could enhance the degrading effect in a concentration-dependent manner. We then validated the CP-Aβ interaction using total internal reflection fluorescence (TIRF) microscopy, fluorescence photometer, and fluorescence polarization measurement. Based on the above discovery, we hypothesized that other MCOs had similar Aβ-degrading functions. Indeed, we found that other MCOs could induce Aβ degradation as well. Remarkably, we revealed that ascorbate oxidase (AO) had the strongest degrading effect among the tested MCOs. Using induced pluripotent stem (iPS) neuron cells, we observed that AO could rescue neuron toxicity which induced by Aβ oligomers. In addition, our electrophysiological analysis with brain slices suggested that AO could prevent an Ab-induced deficit in synaptic transmission in the hippocampus. To the best of our knowledge, our report is the first to demonstrate that MCOs have a degrading function for peptides/proteins. Further investigations are warranted to explore the possible benefits of MCOs for future AD treatment.

Disulfiram (Tetraethylthiuram Disulfide) in the Treatment of Lyme Disease and Babesiosis: Report of Experience in Three Cases

Three patients, each of whom had required intensive open-ended antimicrobial therapy for control of the symptoms of chronic relapsing neurological Lyme disease and relapsing babesiosis, were able to discontinue treatment and remain clinically well for periods of observation of 6–23 months following the completion of a finite course of treatment solely with disulfiram. One patient relapsed at six months and is being re-treated with disulfiram.

Substituted carbamothioic amine-1-carbothioic thioanhydrides as novel trichomonicidal fungicides: Design, synthesis, and biology

Sexually transmitted diseases like trichomoniasis along with opportunistic fungal infections like candidiasis are major global health burden in female reproductive health. In this context a novel non-nitroimidazole class of substituted carbamothioic amine-1-carbothioic thioanhydride series was designed, synthesized, evaluated for trichomonacidal and fungicidal activities, and was found to be more active than the standard drug Metronidazole (MTZ). Compounds were trichomonicidal in the MIC ranges of 4.77-294.1 μM and 32.46-735.20 μM against MTZ-susceptible and -resistant strains, respectively. Further, compounds inhibited the growth of at least two out of ten fungal strains tested at MIC of 7.50-240.38 μM. The most active compound (20) of this series was 3.8 and 9.5 fold more active than the MTZ against the two Trichomonas strains tested. Compound 20 also significantly inhibited the sulfhydryl groups present over Trichomonas vaginalis and was found to be more active than the MTZ in vivo. Further, a docking analysis carried out with cysteine proteases supported their thiol inhibiting ability and preliminary pharmacokinetic study has shown good distribution and systemic clearance.

Interaction of disulfiram with antiretroviral medications: efavirenz increases while atazanavir decreases disulfiram effect on enzymes of alcohol metabolism

BACKGROUND AND OBJECTIVES

Alcohol abuse complicates treatment of HIV disease and is linked to poor outcomes. Alcohol pharmacotherapies, including disulfiram (DIS), are infrequently utilized in co-occurring HIV and alcohol use disorders possibly related to concerns about drug interactions between antiretroviral (ARV) medications and DIS.

METHOD

This pharmacokinetics study (n=40) examined the effect of DIS on efavirenz (EFV), ritonavir (RTV), or atazanavir (ATV) and the effect of these ARV medications on DIS metabolism and aldehyde dehydrogenase (ALDH) activity which mediates the DIS-alcohol reaction.

RESULTS

EFV administration was associated with decreased S-Methyl-N-N-diethylthiocarbamate (DIS carbamate), a metabolite of DIS (p=.001) and a precursor to the metabolite responsible for ALDH inhibition, S-methyl-N,N-diethylthiolcarbamate sulfoxide (DETC-MeSO). EFV was associated with increased DIS inhibition of ALDH activity relative to DIS alone administration possibly as a result of EFV-associated induction of CYP 3A4 which metabolizes the carbamate to DETC-MeSO (which inhibits ALDH). Conversely, ATV co-administration reduced the effect of DIS on ALDH activity possibly as a result of ATV inhibition of CYP 3A4. DIS administration had no significant effect on any ARV studied.

DISCUSSION/CONCLUSIONS

ATV may render DIS ineffective in treatment of alcoholism.

FUTURE DIRECTIONS

DIS is infrequently utilized in HIV-infected individuals due to concerns about adverse interactions and side effects. Findings from this study indicate that, with ongoing clinical monitoring, DIS should be reconsidered given its potential efficacy for alcohol and potentially, cocaine use disorders, that may occur in this population.

A urinary metabonomics study on biochemical changes in yeast-induced pyrexia rats: a new approach to elucidating the biochemical basis of the febrile response

Fever is a prominent feature of many diseases, such as infection, inflammation and trauma. In the clinic, fever can be easily judged by measuring the body temperature; however, the pathogenesis of fever is still not fully understood. A febrile response is a systemic pathological process that can cause metabolic disorders. Metabonomics can provide powerful tools to reveal the pathological mechanisms for such a systemic disease. Thus, to reveal subtle metabolic changes under the condition of fever and to explore its mechanism, an ultra performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry metabonomics approach was employed to investigate the urine biochemical characteristics of yeast-induced pyrexia rats. The acquired data were subjected to principal component analysis for differentiating the pyrexia rats from the control rats. Potential biomarkers were screened by using orthogonal partial least-squares-discriminant analysis and were identified by accurate mass, database, and MS/MS fragment information obtained from the MS(E) technique. Sixteen metabolites in rat urine were identified as potential biomarkers. The relative intensities of the 15 potential biomarkers were calculated. The thermoregulatory circuitry of "endogenous pyrogen (EP) ↑-hypothalamus Na⁺/Ca²⁺-cAMP↑" was partially confirmed in this study. The results suggested that UPLC/MS-based metabolic profiling of rat urine identifies impaired tryptophan metabolism as the mechanism of yeast-induced fever. This research provided informative data that the impaired tryptophan metabolism might be one of the important reasons in elucidating the biochemical basis of the febrile response.