Cyclophosphamide in multiple sclerosis: scientific rationale, history and novel treatment paradigms

For patients with relapsing-remitting multiple sclerosis (RRMS), there are currently six approved medications that have been shown to alter the natural course of the disease. The approved medications include three beta interferon formulations, glatiramer acetate, natalizumab and mitoxantrone. Treating aggressive forms of RRMS and progressive disease forms of MS still presents a great challenge to neurologists. Intense immunosuppression has long been thought to be the only feasible therapeutic option. In patients with progressive forms of MS, lymphoid tissues have been detected in the central nervous system (CNS) that may play a critical role in perpetuating local inflammation. Agents that are currently approved for patients with MS have no or very limited bioavailability in the brain and spinal cord. In contrast, cyclophosphamide (CYC), an alkylating agent, penetrates the blood-brain barrier and CNS parenchyma well. However, while CYC has been used in clinical trials and off-label in clinical practice in patients with MS for over three decades, data on its efficacy in very heterogeneous groups of study patients have been conflicting. New myeloablative treatment paradigms with CYC may provide a therapeutic option in patients that do not respond to other agents. In this article we review the scientific rationale that led to the initial clinical trials with CYC. We will also outline the safety, tolerability and efficacy of CYC and provide neurologists with guidelines for its use in patients with MS and other inflammatory disorders of the CNS, including neuromyelitis optica (NMO). Finally, an outlook into relatively novel treatment approaches is provided.

Analysis of the extracts of Isatis tinctoria by new analytical approaches of HPLC, MS and NMR

The methods of extraction, separation and analysis of alkaloids and indole glucosinolates (GLs) ofIsatis tinctoria were reviewed. Different analytical approaches such as High-pressure Liquid Chromatography (HPLC), Liquid Chromatography with Electrospray Ionization Mass Spectrometry (LC/ESI/MS), Electrospray Ionization Time-Of-Flight Mass Spectrometry (ESI-TOF-MS), and Nuclear Magnetic Resonance (NMR) were used to validate and identity of these constituents. These methods provide rapid separation, identification and quantitative measurements of alkaloids and GLs of Isatis tinctoria. By connection with different detectors to HPLC such as PDA, ELSD, ESI- and APCI-MS in positive and negative ion modes, complicated compounds could be detected with at least two independent detection modes. The molecular formula can be derived in a second step of ESI-TOF-MS data. But for some constituents, UV and MS cannot provide sufficient structure identification. After peak purification, NMR by semi-preparative HPLC can be used as a complementary method.

Discovery of CS-0777: A Potent, Selective, and Orally Active S1P1 Agonist

CS-0777 (3) is phosphorylated in vivo, and the phosphate of CS-0777 (CS-0777-P) (4) acts as a selective S1P receptor-1 (S1P1) modulator. We report herein the synthesis of CS-0777 and CS-0777-P, pharmacological effects such as S1P1 and S1P3 agonist activity in vitro, peripheral blood lymphocyte lowering effects and the suppressive effect on experimental autoimmune encephalomyelitis (EAE), and also the pharmacokinetics in rats. CS-0777-P had ∼320-fold greater agonist activity for human S1P1 (EC50; 1.1 nM) relative to S1P3 (EC50; 350 nM). Following administration of single oral doses of 0.1 and 1 mg/kg of CS-0777 in rats, lymphocyte counts decreased significantly, with a nadir at 12 h postdose and recovery to vehicle control levels by 5 days postdose. In the EAE model compared to the vehicle-treated group, significant decreases in the cumulative EAE scores were observed for the 0.1 and 1 mg/kg CS-0777 groups in rats. CS-0777 is currently in clinical trials for the treatment of multiple sclerosis (MS).

Detection, isolation and characterization of principal synthetic route indicative impurities in verapamil hydrochloride

Two unknown impurities were detected in verapamil hydrochloride bulk drug using isocratic reversed-phase high performance liquid chromatography (HPLC). These impurities were isolated by preparative HPLC. Spectral data for the isolated impurities were collected. Based on the spectral data derived from two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy and mass spectrometry (MS), impurity-1 and impurity-2 were characterized as 2-(3,4-dimethoxyphenyl)-3-methylbut-2-enenitrile and 2-(3,4-dimethoxyphenyl)-2-isopropyl-3-methylbutanenitrile, respectively.

Understanding the roles of the kynurenine pathway in multiple sclerosis progression

The kynurenine pathway (KP) is a major degradative pathway of tryptophan ultimately leading to the production of nicotinamide adenine dinucleotide (NAD⁺) and is also one of the major regulatory mechanisms of the immune response. The KP is known to be involved in several neuroinflammatory disorders including Alzheimer’s disease, amyotrophic lateral sclerosis, AIDS dementia complex, Parkinson’s disease, schizophrenia, Huntington’s disease and brain tumours. However, the KP remains a relatively new topic for the field of multiple sclerosis (MS). Over the last 2–3 years, some evidence has progressively emerged suggesting that the KP is likely to be involved in the pathogenesis of autoimmune diseases especially MS. Some KP modulators are already in clinical trials for other inflammatory diseases and would potentially provide a new and important therapeutic strategy for MS patients. This review summarizes the known relationships between the KP and MS.

Evaluation of the new MALDI matrix 4-chloro-alpha-cyanocinnamic acid

MALDI-TOF continues to be an important tool for many proteomic studies. Recently, a new rationally designed matrix 4-chloro-alpha-cyanocinnamic acid was introduced, which is reported to have superior performance as compared with the "gold standard" alpha-cyano-4-hydroxycinnamic acid (CHCA). In this study, the performance of this new matrix, using the Shimadzu Biotech Axima TOF(2) (Shimadzu Biotech, Manchester, UK), was investigated. The overall sequence coverage as well as sensitivity of this matrix were compared with CHCA using standard protein tryptic digests. The performance of this matrix with labile peptides, such as phosphopeptides and 4-sulfophenyl isothiocynate-derivatized peptides, to facilitate de novo sequencing was also explored. This matrix was found to be better performing than CHCA in overall sensitivity and showed better sequence coverage at low-digest levels, partly as a result of less of a bias for arginine-containing peptides. It also showed as much as a tenfold improvement in sensitivity with labile peptides on standard stainless-steel targets. In addition, as a result of the much cooler nature of this matrix, labile peptides are readily seen intact with much less fragmentation in mass spectrometry (MS) mode. This matrix was also evaluated in the MS/MS fragmentation modes of post-source decay (PSD) and collisional-induced dissociation (CID). It was found that fragmentation occurs readily in CID, however as a result of the very cool nature of this new matrix, the PSD fragments were quite weak. This matrix promises to be an important addition to the already extensive array of MALDI matrices.

Metabolic Fingerprinting in Toxicological Assessment Using FT-ICR MS

Detection of the toxicity of a candidate compound at an early stage of drug development is an emerging area of interest. It is difficult to determine all of the effects of metabolism of a compound using traditional approaches such as histopathology and serum biochemistry. The goal of a metabolomics approach is to determine all metabolites in a living system, with the potential to detect and identify biomarkers involved in toxicity onset. Here, we summarize the metabolic fingerprints for detection and identification of metabolic changes and biomarkers related to drug-induced toxicity using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS).

Diverse protein regulations on PHA formation in Ralstonia eutropha on short chain organic acids

Organic acids are considered as potential substrates for biosynthesis of polyhydroxyalkaonates. The acids may also be the metabolic inhibitors at moderate concentration levels. In this study, Ralstonia eutropha was used to elucidate the protein regulations when the bacterial cells pre-cultivated on glucose were exposed to three representative short chain organic acids, acetic, propionic and levulinic acids. The research compared and examined the proteins that might participate in PHA metabolism, primary metabolism, and cell's defense systems. A number of proteins were found to be induced in R. eutropha by using 1D-PAGE and nano-liquid chromatography tandem MS/MS. With the proteins being up-regulated, a dramatic change occurred in the induction of PHA metabolism, including fatty acid biosynthesis for acetate, β-oxidation for propionate and both for levulinic acid. Acetate kinase was induced in response to the presence of acetate or levulinic acid. The organic acids induced several proteins involved in amino acid biosynthesis, purine and pyrimidine biosynthesis, and cofactor biosynthesis in R. eutropha, but the regulations had a great variation. R. eutropha might employ different regulation mechanisms to maintain cell growth and PHA formation when the cells are exposed to the organic acids as sole source of carbon and energy.

Genetic determinants of hyperhomocysteinemia in atherosclerosis

Hyperhomocysteinemia (Hhcy) is an independent risk factor for the development of atherosclerosis. The mechanisms by which HHcy promotes cardiovascular disease may be due to activation of pro-inflammatory factors, endoplasmic reticulum (ER) stress and oxidative stress. We aimed to study (i) gene mutations that cause HHcy. (ii) Estimation of inflammatory marker like ultrasenitive C-reactive proteins (hs-CRP) and total antioxidant levels (iii) determination of Hcy- dependent gene expression in vivo. 25 HHcy patients and 25 healthy controls were taken for this study. Mutation detection in MTHFR, CBS, MS and eNOS gene was by PCR-based restriction enzyme analysis and subsequently expression study was carried out by Reverse Transcriptase PCR and cloning technique. A significant association of HHcy with MTHFR (C677T) and MS (A2756G) genotype was observed (p<0.05). There was no association of Hhcy and eNOS genotype. The Hhcy patients, showed no expression of the ER stress gene, GRP78 in lymphocytes. Our study showed no effect of Hcy on the CD18 gene (pro-inflammatory pathway) expression, but a significant association of tHcy and hs-CRP levels in HHcy grp (t=2.28, p<0.05). This shows that HHcy induces inflammatory response, which could lead to tissue injury in the pathogenesis of the atherosclerotic process. Our findings show higher mRNA expression of manganese superoxide dismutase (Mn SOD) in HHcy group as compared to the control group. The Total Antioxidant Status (TAS) estimated was found to be significantly lower in the HHcy group as compared to healthy normals (t=4.8, p<0.01). Taken together these findings strongly suggest that the adverse effects of homocysteine are at least partly mediated by oxidative stress. Our study supports the hypothesis that Hcy evokes adverse vascular effects by promoting oxidative damage to endothelial cells.

The analysis of N-glycolylneuraminic acid(NeuGc) of hepatoma tissue and K562 cell ferritins using HPLC and mass spectrometry

Ferritin is an iron-storage protein and its serum level is known to increase in the patient of with inflammation and malignant tumor. To further elucidate the difference between ferritins from normal human liver tissue and that of cancer cells, their sialic acids were analyzed. The Western blot analysis and the cytochemical staining using anti-NeuGc antiserum indicated that ferritins from the human hepatocarcinoma tissue and malignant K562 cells contain NeuGc, but that from the normal liver does not. The result was also confirmed by HPLC analysis and MALDI-TOF/MS analysis of sialic acids which were derivatized by the DMB method. It was also shown that the sialic acid content in hepatocarcinoma ferritin was much higher than that in the normal liver ferritin. These results suggest that normal and cancerous liver ferritins are qualitatively and quantitatively different in sialylation. In addition, K562 cells were shown to express NeuGc even if the cells were cultured in serum-free media which lack NeuGc. This is of interest from the current concept that expression of NeuGc in human cells is due to uptake and utilization of exogenous NeuGc.