A review of phenformin, metformin, and imeglimin.

Diabetes mellitus is a serious metabolic disorder affecting millions of people worldwide. Phenformin and metformin are biguanide antidiabetic agents that are conveniently synthesized in a single-step chemical reaction. Phenformin was once used to lower blood glucose levels, but later withdrawn from the market in several countries because it was frequently associated with lactic acidosis. Metformin is still a widely prescribed medication for the treatment of type 2 diabetes despite the introduction of several newer antidiabetic agents. Metformin is administered orally and has desirable pharmacokinetics. Incidence of metformin-induced lactic acidosis is serious but very rare. Imeglimin, a novel molecule being investigated by Poxel and Sumitomo Dainippon Pharma in Japan, is currently in clinical trials for the treatment of type 2 diabetes. Unlike metformin, imeglimin is a cyclic molecule containing a triazine ring. However, like metformin, imeglimin is also a basic small molecule. Imeglimin is synthesized from metformin as a precursor via a single step chemical reaction. Recent mechanism of action studies suggests that imeglimin improves mitochondria function, when given in combination with metformin it helps achieve better glycemic control in patients with type 2 diabetes. We herein describe and compare the current status, synthesis, physicochemical properties, pharmacokinetic parameters, mechanism of action, and preclinical/clinical studies of metformin and imeglimin.

The effect of repeated testing of pharmacy calculations and drug knowledge to improve knowledge retention in pharmacy students.

BACKGROUND AND PURPOSE: Repeated testing has been shown to improve knowledge retention in students. However, there is limited literature on the effect of repeated testing in pharmacy students. Our objective was to determine if repeated testing improved retention of pharmacy calculations and drug knowledge. EDUCATIONAL ACTIVITY AND SETTING: Second, third, and fourth year pharmacy students were invited to participate in this voluntary study. Participants were divided into GPA categories and randomly assigned to a control or study group. Seven quizzes were given to the study group over one academic year. No quizzes were given to the control group. Both groups had access to the question bank from which the quizzes were constructed. A final exam and survey were given to both groups at the end of the study. FINDINGS: We did not find an effect of repeated testing on knowledge retention for the study group compared to the control group in the study. However, when fourth year students were excluded from the analysis, we observed a benefit of repeated testing for lower-performing students. Over 90% of survey respondents agreed that repeated testing promoted long term knowledge and that students should test themselves repeatedly. However, approximately 60% of students admitted to not testing themselves repeatedly. Nearly 85% of survey respondents agreed that the school should implement a repeated testing program. SUMMARY: Overall, students believe repeated testing is beneficial, but few do it on their own. Repeated testing showed a benefit in at-risk students. Implementing a program of repeated testing can help low-performing students succeed academically.

Alzheimer's Drug Discovery Maze: A Snap View of the Past Decade's Diverse Pharmacological Targets for the Disorder.

The discovery of disease modifying anti-Alzheimer's molecules continues to be dared by: disease target multiplicity, downstream neurodegenerative biochemistry complexities, and genotype implications. A confluence of the above ingredients has contributed to a pipeline of creative molecules that regrettably underperform in clinical trials. Thus far, only five palliative pharmacotherapeutic agents, that is, four acetylcholine potentiating agents and an N-methyl-D-aspartate (NMDA) antagonist are clinically available. In this review we collectively describe the currently suggested targetable pathways for designing anti-Alzheimer's agents (palliative and/or disease modifying). We are prompted to contribute in this manner out of a desire to simplify and consolidate, to a certain extent, the divergent target literature on Alzheimer's drug discovery. We herein provide a summary update and perspective on realized and potentially druggable pharmacological targets for this CNS disorder. This article covers mostly the 2005-2015 medicinal chemistry/pharmacological/biological literature space on the subject.

The Validation of a Case-Based, Cumulative Assessment and Progressions Examination.

OBJECTIVE: To assess content and criterion validity, as well as reliability of an internally developed, case-based, cumulative, high-stakes third-year Annual Student Assessment and Progression Examination (P3 ASAP Exam). METHODS: Content validity was assessed through the writing-reviewing process. Criterion validity was assessed by comparing student scores on the P3 ASAP Exam with the nationally validated Pharmacy Curriculum Outcomes Assessment (PCOA). Reliability was assessed with psychometric analysis comparing student performance over four years. RESULTS: The P3 ASAP Exam showed content validity through representation of didactic courses and professional outcomes. Similar scores on the P3 ASAP Exam and PCOA with Pearson correlation coefficient established criterion validity. Consistent student performance using Kuder-Richardson coefficient (KR-20) since 2012 reflected reliability of the examination. CONCLUSION: Pharmacy schools can implement internally developed, high-stakes, cumulative progression examinations that are valid and reliable using a robust writing-reviewing process and psychometric analyses.

SAR analysis of adenosine diphosphate (hydroxymethyl)pyrrolidinediol inhibition of poly(ADP-ribose) glycohydrolase.

Polyadenosine diphosphoribose glycohydrolase (PARG) catalyzes the intracellular hydrolysis of adenosine diphosphoribose polymers. Because structure-activity data are lacking for PARG, the specific inhibitor adenosine diphosphate (hydroxymethyl)pyrrolidinediol (ADP-HPD) was utilized to determine the effects of structure on inhibitor potency using PARG isolated from bovine thymus (bPARG) and recombinant bovine PARG catalytic fragment (rPARG-CF). Both enzymes were strongly inhibited by submicromolar levels of ADP-HPD, but ADP and the phosphorylated pyrrolidine displayed no activity. Utilizing ADP-HPD analogues containing 2-, N(6), or 8-adenosyl substituents or guanine instead of adenine, the importance of adenine ring recognition as well as a correlation between loss of PARG inhibition and the length and bulkiness of 8-adenosyl substituents was shown. Utilization of ADP-HPD analogues lacking one or both pyrrolidine cis-hydroxyls demonstrated their importance for inhibitor binding. Last, the similarity between naturally occurring bPARG and heterologously expressed rPARG-CF was demonstrated. Therefore, readily available rPARG-CF is suitable for use in future studies to determine the structural aspects of PARG.

Identification of an inhibitor binding site of poly(ADP-ribose) glycohydrolase.

Polymers of ADP-ribose involved in the maintenance of genomic integrity are converted to free ADP-ribose by the action of poly(ADP-ribose) glycohydrolase (PARG). As an approach to mapping functions of PARG onto the amino acid sequence of the protein, we report here experiments that identify an amino acid residue involved in the binding of potent PARG inhibitors. A photoreactive inhibitor, [alpha-(32)P]-8-azidoadenosine diphosphate (hydroxymethyl)pyrrolidinediol (8-N(3)-ADP-HPD), was used to photolabel a recombinant bovine PARG catalytic fragment (rPARG-CF). N-Terminal sequencing of tryptic and subtilitic peptides of photoderivatized rPARG-CF identified tyrosine 796 (Y796), a residue conserved in PARG across a wide range of organisms, as a site of photoderivatization. Site-directed mutants where this tyrosine residue was replaced with an alanine residue (Y796A) had a nearly 8-fold decrease in catalytic efficiency (k(cat)/K(M)), while replacement with a tryptophan residue (Y796W) had little effect on catalytic efficiency. Surface plasmon resonance spectroscopy using the PARG inhibitor 8-(aminohexyl)amino-ADP-HPD demonstrated that the binding constant of the inhibitor for Y796A was 21-fold lower (K(D) = 170 nM) than that of wild-type PARG (K(D) = 8.2 nM), while Y796W displayed a binding affinity similar to that of the wild-type enzyme. Our results indicate that Y796 is involved in inhibitor binding to PARG via a ring stacking interaction and identify a highly conserved region of the protein that putatively contains other residues involved in catalytic activity and/or substrate recognition.