Mini Reviews in Medicinal Chemistry - Volume 15, Issue 14, 2015

Painful diabetic neuropathy (PDN) is one of most common complication of diabetes, usually affecting 50% of diabetic patients and remains important cause of morbidity, mortality and deterioration of quality of life. PDN is well characterised by chronic hyperglycemia, alterations in expression and kinetics of voltage-gated sodium channels (VGSCs) and neuro-inflammation which together may result into sensorimotor deficits in peripheral nervous system. Peripheral nociceptive neurons express variety of sodium channel isoforms particularly Nav1.3, Nav1.7, Nav1.8 and Nav1.9, each play a key role in physiology of nociception by undergoing respective dynamic changes in expression and voltage-dependent gating properties. Thus, they are critical determinants of sensory neuronal excitability and associated neuropathic pain signal. Recent preclinical and clinical trial research has shed light on VGSCs as most compelling target in the treatment of PDN, a development that may open up new therapeutic approaches involving subtype selective sodium channel blockers to boost clinical efficacy, cost effectiveness, better tolerability and targeted treatment. In this review, we have summarized structure and functions of VGSCs and their involvement in the pathophysiology of neuropathic pain along with the current status of pharmacological interventions targeted at VGSCs in the treatment of diabetic neuropathy.

A natural pentacyclic triterpenoid oleanolic acid 1 and its biotransformed metabolites 2-3 are potential α-glucosidase inhibitors. To elucidate the inhibitory mechanism of compounds 1, 2 and 3 against α-glucosidase, we calculated (i) their electronic and optical properties using DFT and TD-DFT at the B3LYP/6-31G(d) level in gas and IEF-PCM solvent; and (ii) their binding energies to α-glucosidase via docking study. DFT results showed that the α-glucosidase inhibtion is mainly depend on the polarity parameters of the studied compounds. Docking results revealed that the activity increased with binding energies (i.e. the stability of ligand-receptor complex). The specroscopic data of oleanolic acid 1 and its metabolites 2 and 3 are well predicetd for 13C NMR chemical shifts (R2=99%) and 1H NMR chemical shifts (R2=90%); and for (ii) UV/vis spectra. The assignments and interpretation of NMR chemical shifts and bathochromic shift of λMAX absorption bands are discussed.

Diseases started even before the existence of human beings. Therefore, when the civilization began, the biggest threats for human were diseases. Man has made several sincere attempts for the search of new drugs in order to cure and control different diseases. Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder that accounts for about 85-95% of all diagnosed cases of diabetes. It is characterized by abnormalities in glucose homeostasis in many organs, and is associated with considerable morbidity and mortality. Extensive research has been carried out using rational drug design to identify and optimize new leads for molecular targets of T2DM, which include Heterocyclic compounds, metal complexes, H3 receptor antagonists, glucagon receptor antagonists and human incretin-degrading enzyme dipeptidyl peptidase IV inhibitors.

Hyperglycemia recognized during hospitalization for acute coronary syndromes (ACS) is common. It is a powerful predictor of worse prognosis in patients both with and without previously known diabetes mellitus. Hyperglycemia during ACS is caused by an inflammatory and adrenergic response to ischemic stress, when catecholamines are released and glycogenolysis induced. The link between hyperglycemia and prognosis in ACS patients is multi-factorial. Hyperglycemia exerts detrimental effects on left ventricular and platelet function and it also activates other systemic pathological processes that contribute to cellular and tissue injury such as increasing oxidative stress and worsening endothelial function. Glucose management strategies in ACS may improve outcome in patients with hyperglycemia, by reducing inflammatory and clotting mediators, by improving endothelial function and fibrinolysis and by reducing infarct size. Most of available oral anti-diabetic drugs are contraindicated for the increased risk of hypoglycemia. Thus, insulin is the preferred agent for glycemic control in ACS and conversion from intravenous to subcutaneous therapy commonly occurs when the critical acute phase of ACS resolves. Pharmacodynamics of insulin allows it to be adaptable to the changing physiology of the ACS patient, is easily titrated and has no dosage threshold. Nevertheless, findings concerning the effect on ACS-related mortality of the control of glucose levels by intravenous infusion of insulin have been conflicting and intervention trials are needed to optimize the definition of hyperglycemia and to establish appropriate modalities and goals of glucose lowering treatment. In particular, the clinical benefit of an aggressive treatment with insulin is yet unproved.

Tuberculosis is a leading killer of lives worldwide and the global curse of multi-drug resistant tuberculosis is attaining really dangerous levels. Synergistic interaction of HIV and TB is the twin epidemics in resource-limited countries as each potentiate progression of the other. The increasing emergence of MDR-TB and XDR-TB place an immense burden for the treatment of TB with currently available drugs. The situation urgently demands for the discovery of new drugs with novel mode of action and differs in structural features in order to overcome resistance appears in conventional TB therapeutics. The present report covers the discovery of three classes of antituberculosis drugs, Nitroimidazoles, Quinolones and Oxazolidinones, undergoing clinical development with fluorine atom in their structures. Highly electronegative fluorine atom plays a signature role in advancing medicinal innovations as it existence in the drug compounds critically influences metabolic stability and lipophilicity thereby delaying its elimination by the body which results into a long term in vivo efficiency of the drug. Presence of fluorine atom(s) in the drug structures described in this report, has been associated with the several fold increase in the overall potency of the compound as demonstrated since the early discoveries. 6 Fluorinated derivatives from these three classes as pretomanid, delamanid, moxifloxacin, gatifloxacin, linezolid and sutezolid have been discussed with their antituberculosis effects, mode of action, chemical synthetic routes and results of clinical studies.

Non-alcoholic fatty liver disease encompasses a spectrum of pathologies ranging from simple steatosis to non-alcoholic steatohepatitis. Patients with non-alcoholic steatohepatitis have increased risk of cirrhosis, liver failure and hepatocellular carcinoma. About 25% of subjects with simple steatosis progress to steatohepatitis; nowadays, the detailed pathological factors influencing the progression of non-alcoholic fatty liver disease remains unclear. It is proposed that genetic and environmental factors interact to determine the disease phenotype. Epigenetics could explain some relationships between genes and external influences. The epigenetic changes that have been related to non-alcoholic fatty liver disease are DNA methylation, onecarbon metabolism, histone modifications and the presence of micro-RNA. DNA methylation and micro-RNAs have been investigated in human samples, whereas histone modifications have only been studied until now in animal and cellular models. The aim of this study is to review the most relevant information about epigenetic changes in non-alcoholic steatohepatitis.

Lens epithelium-derived growth factor (LEDGF/p75) plays an essential role in the HIV-1 replication. It acts by tethering integrase (IN) into the host cellular chromatin. Due to its significance of the IN-LEDGF/p75 interaction affords a novel therapeutic approach for the design of new classes of antiretroviral agents. To date, many small molecules have been found to be the inhibitors of INLEDGF/ p75 interaction. This review summarizes recent advances in the development of potential structure-based IN-LEDGF/p75 interaction inhibitors. The work will be helpful to shed light on the antiretroviral drug development pipeline in the next future.

Lipases are part of the family of hydrolases that act on carboxylic ester bonds. They are involved in catalyzing the hydrolysis of triglycerides (TG) into chylomicrons and very low density lipoprotein (VLDL) particles. Uses of lipases are evolving rapidly and currently they are reported to show high potential in medicine. Intensive study and investigations have led researchers to explore lipases for their use in substitution therapy, where in enzyme deficiency during diseased conditions is compensated by their external administration. In our body, they are used to break down fats present in food so that they can be absorbed in the intestine and deficiency of lipases leads to malabsorption of fats and fat-soluble vitamins. Lipases help a person who has cystic fibrosis, Alzheimer’s disease, atherosclerosis and act as a candidate target for cancer prevention and therapy. They act as diagnostic tool and their presence or increasing levels can indicate certain infection or disease. Obesity causes metabolic disease and is a serious health problem around the world. Thus inhibiting digestive lipase to reduce fat absorption has become the main pharmacological approach to the treatment of obesity in recent years.