Role of MC-1 alone and in combination with tissue plasminogen activator in focal ischemic brain injury in rats

A Novel Two-Dimensional Liquid Chromatography Combined with Ultraviolet Detection Method for Quantitative Determination of Pyridoxal 5'-Phosphate, 4-Pyridoxine Acid and Pyridoxal in Animal Plasma

Vitamin B₆ is an indispensable micronutrient in organisms and is widely distributed in blood, tissues, and organs. Changes in the content and ratio of vitamin B6 can affect the entire physiological condition of the body, so it becomes particularly important to reveal the relationship between changes in its content and disease by monitoring vitamin B6 levels in the organism. In this study, a two-dimensional liquid chromatography-UV detector (2D-LC-UV) was used to establish a method for the simultaneous detection of PLP, PA, and PL for the first time. First, PLP, PA, and PL were extracted with plasma: 0.6 M TCA: ultrapure water = 1:2:3 (v/v/v) and then derivatized. Enrichment and preliminary separation were performed on a one-dimensional column and automatically entered into a two-dimensional column for further separation. This method exhibited good selectivity, and the correlation coefficients for the analyte calibration curves were >0.99. The detection limits for PLP, PA, and PL were 0.1, 0.2, and 4 nmol/L, respectively. The results showed that the system has high loading capacity, excellent resolution, and a good peak shape. This method is expected to provide applicability for the determination of PLP, PA, and PL in pharmacological, pharmaceutical, and clinical research.

Identification of biomarkers and candidate small-molecule drugs in lipopolysaccharide (LPS)-induced acute lung injury by bioinformatics analysis

BACKGROUND/OBJECTIVE

Acute lung injury (ALI) is a critical clinical syndrome with high rates of incidence and mortality. However, its molecular mechanism remains unclear. The current work aimed to explore the molecular mechanisms of ALI by identifying different expression genes (DEGs) and candidate drugs using a combination of chip analysis and experimental validation.

METHODS

Three microarray datasets were downloaded from Gene Expression Omnibus (GEO) database to obtain DEGs. We conducted a Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway-enrichment analyses of overlapping DEGs among three databases. The expression level of key gene was verified by Western blotting analysis in LPS-treated ALI cell models. Finally, we predicted the candidate drugs targeting the key gene that might be effective for ALI treatment, and the role of candidate drug in treating ALI was verified by investigation.

RESULTS

A total 29 overlapping DEGs were up-regulated in LPS-induced ALI groups. They were enriched in inflammation and inflammation-related pathways. Serpin family A member 3 (SERPINA3) was defined as a key gene because it was associated with inflammation pathway and up-regulated in microarray datasets in LPS-induced ALI. In LPS-induced human bronchial epithelial cells transformed with Ad12-SV40-2B (BEAS-2B) cells, SERPINA3 was enhanced. Pyridoxal phosphate as an upstream drug of SERPINA3 could improve cell viability and reduce expression inflammatory factors in LPS-treated BEAS-2B cells.

CONCLUSION

Our study suggested that pyridoxal phosphate could be a candidate drug targeting SERPINA3 gene in LPS-induced ALI. It has protective and anti-inflammatory effects in BEAS-2B cells, and may become a potential novel treatment for ALI.

Advances in treatment strategies for ischemia reperfusion injury

INTRODUCTION

Ischemia-reperfusion injury (IRI) involves a complex sequence of events and limits the outcome of various surgical interventions. Clinical trials, based on the data of experimental models, aim to prove whether a pharmacological or technical approach could be suitable to provide a beneficial effect in humans. Due to the complexity of IRI, few pharmacological treatments have been investigated in clinical Phase III.

AREAS COVERED

In this review we report clinical trials that test specific drugs in clinical trials of organ transplantation. These studies form part of Phase II trials and examine the administration of caspase inhibitors, P-selectin antagonist or an antioxidant component in order to attenuate cold IRI during transplantation. Moreover, we provide a brief description of drugs tested on trials of different clinical situations associated to IRI, such as the coronary artery bypass graft surgery and percutaneous coronary intervention.

EXPERT OPINION

Future clinical trials could be centered on the application of techniques suitable for organs with increased vulnerability toward IRI. Furthermore, the standardization of reliable biomarkers and a careful estimation of the impact of high risk factors may be the key in order to achieve a more critical evaluation of the obtained results.

Antihypertensive and neuroprotective actions of pyridoxine and its derivatives

Vitamin B6 plays a crucial role in the nervous system as the amino acid decarboxylases involved in the synthesis of all putative neurotransmitters requires the coenzyme pyridoxal phosphate. Vitamin B6 in its various forms has antioxidant properties. Pyridoxal phosphate has a role in regulating cellular calcium transport through both the voltage-mediated and ATP-mediated purinergic mechanisms of cellular calcium influx and, hence, has a role in the control of hypertension. Pharmacological doses of vitamin B6 appear to decrease the high blood pressure associated with both genetic and nongenetic models of hypertension. Vitamin B6 has a crucial role in the normal function of the central and peripheral nervous systems. It also protects against ischemia and glutamate-induced neurotoxicity.

A randomized, double-blind, placebo-controlled, multicenter study to evaluate the cardioprotective effects of MC-1 in patients undergoing high-risk coronary artery bypass graft surgery: MC-1 to Eliminate Necrosis and Damage in Coronary Artery Bypass Graft Surgery Trial (MEND-CABG) II--study design and rationale

BACKGROUND

Coronary artery bypass graft (CABG) surgery is effective in relieving angina and improving survival and quality of life in patients with obstructive coronary artery disease; however, recurrent angina, myocardial infarction, neurological injury, and death can occur in the perioperative and postoperative period. MC-1 (pyridoxal 5'-phosphate) is a novel agent that has shown promise in reducing myocardial necrosis by reducing cellular calcium overload after percutaneous coronary intervention and CABG surgery in high-risk patients undergoing these procedures.

METHODS

MEND-CABG II is a phase III study evaluating the efficacy and safety of MC-1 in reducing cardiovascular morbidity and mortality after CABG. High-risk patients undergoing CABG surgery will be randomly assigned to receive either MC-1 (250 mg/d) or matching placebo immediately before and continuing for 30 days after the procedure. The primary end point is the occurrence of cardiovascular death or nonfatal myocardial infarction through postoperative day 30. A total of 3023 patients were enrolled at 130 sites in Canada, the United States, and Germany between October 2006 and September 2007, with results anticipated shortly after completion of 90-day follow-up in March 2008.

CONCLUSIONS

The data from the MEND-CABG II trial will establish whether peri- and postoperative treatment with MC-1 can decrease the short- and intermediate-term morbidity and mortality of high-risk patients undergoing CABG surgery.

Time course of changes in pyridoxal 5'-phosphate (vitamin B6 active form) and its neuroprotection in experimental ischemic damage

In the present study, we investigated ischemia-induced changes of pyridoxal 5'-phosphate synthesizing enzyme and degrading enzyme and neuroprotective effects and roles of pyridoxal 5'-phosphate against ischemic damage in the gerbil hippocampal CA1 region. Pyridoxal 5'-phosphate oxidase and pyridoxal phosphate phosphatase immunoreactivities were changed in neurons up to 2 days after ischemia, while 4 days after ischemia their immunoreactivities were expressed in astrocytes. Pyridoxal 5'-phosphate oxidase immunoreactivity and its protein level were highest 12 h after ischemia, while those in pyridoxal phosphate phosphatase were highest 2 days after ischemia. Total activities of these enzymes were changed after ischemia, but specific activities of the enzymes were not altered. Treatment with pyridoxal 5'-phosphate into brains (4 microg/5 microl, i.c.v.) at 30 min before transient ischemia protected about 80% of CA1 pyramidal cells 4 days after ischemia and induced elevation of glutamic acid decarboxylase 67 immunoreactivity in the CA1 region. However, pyridoxal 5'-phosphate treatment into ischemic brains decreased GABA transaminase immunoreactivity in the CA1 region after ischemia. These results indicate that pyridoxal 5'-phosphate may be associated with the inhibitory discharge of GABA in the hippocampal CA1 neurons, and the increased level of GABA may protect hippocampal CA1 pyramidal cells from ischemic damage.

MC-1 (pyridoxal 5'-phosphate): novel therapeutic applications to reduce ischaemic injury

Despite the overall efficacy of mechanical reperfusion therapies, such as percutaneous coronary intervention and coronary artery bypass graft surgery, in reducing the morbidity and mortality that is associated with acute ischaemic syndromes, many of the treated patients develop ischaemia-reperfusion injury due to impaired microvascular integrity, embolisation of atherothrombotic debris and/or disrupted end-organ metabolism. MC-1 is an investigational drug from Medicure, Inc. In preclinical models of ischaemia and ischaemia-reperfusion injury, treatment with MC-1 has demonstrated significant cardio- and neuroprotective effects. Although the pharmacological activity of MC-1 may involve multiple mechanisms, research suggests that at least part of the protective effect may be mediated through its actions on purinergic receptors. Early clinical experience with MC-1 also appears to be promising: in a recent Phase II evaluation, treatment with MC-1 was associated with a statistically significant reduction in periprocedural infarct size (as measured by area under the curve creatine kinase-myocardial band) among high-risk patients undergoing elective percutaneous coronary intervention. Based on these findings, larger, randomised trials to confirm the safety and efficacy of MC-1 in the setting of coronary artery revascularisation with coronary artery bypass graft, acute coronary syndromes and stroke are ongoing or in development. These forthcoming evaluations should clarify the safety and efficacy of MC-1 and improve the understanding regarding its potential therapeutic role in a variety of clinical settings and indications.