5-hydroxyindole-2-carboxylic acid amides: novel histamine-3 receptor inverse agonists for the treatment of obesity

Obesity is a major risk factor in the development of conditions such as hypertension, hyperglycemia, dyslipidemia, coronary artery disease, and cancer. Several pieces of evidence across different species, including primates, underscore the implication of the histamine 3 receptor (H(3)R) in the regulation of food intake and body weight and the potential therapeutic effect of H(3)R inverse agonists. A pharmacophore model, based on public information and validated by previous investigations, was used to design several potential scaffolds. Out of these scaffolds, the 5-hydroxyindole-2-carboxylic acid amide appeared to be of great potential as a novel series of H(3)R inverse agonist. Extensive structure-activity relationships revealed the interconnectivity of microsomal clearance and hERG (human ether-a-go-go-related gene) affinity with lipophilicity, artificial membrane permeation, and basicity. This effort led to the identification of compounds reversing the (R)-alpha-methylhistamine-induced water intake increase in Wistar rats and, further, reducing food intake in diet-induced obese Sprague-Dawley rats. Of these, the biochemical, pharmacokinetic, and pharmacodynamic characteristics of (4,4-difluoropiperidin-1-yl)[1-isopropyl-5-(1-isopropylpiperidin-4-yloxy)-1H-indol-2-yl]methanone 36 are detailed

Histamine-3 Receptor Inverse Agonists for the Treatment of Obesity: Validation of the Target and Identification of Novel Series

Obesity is a major risk factor for the development of conditions such as hypertension, hyperglycemia, dyslipidemia, coronary artery disease and cancer. Several pieces of evidence, including data in primates, have demonstrated the beneficial effects of histamine-3 receptor (H 3 R) inverse agonists in the regulation of food intake and body weight. A pharmacophore model based on selected published H 3 R ligands and validated by previ- ous investigations, was used to identify the 5-oxy-2-carboxamide-indole core as a novel series of H 3 R inverse agonists. Extensive structure-activity relationship (SAR) investigations were rewarded by the identification of several compounds reversing ( R )- α -methyl-histamine-induced water intake increase and reducing food intake/ body weight in rodent models of obesity. Among those compounds, (4,4-difluoro-piperidin-1-yl)-[1-isopropyl-5- (1-isopropyl-piperidin-4-yloxy)-1 H -indol-2-yl]-methanone, selected as a lead compound, was exhibiting a prom- ising profile, including excellent pharmacokinetic properties, good in vitro safety profile and high efficacy in a chronic rodent model of obesity

The Q175 Mouse Model of Huntington’s Disease Shows Gene Dosage- and Age-Related Decline in Circadian Rhythms of Activity and Sleep

<div><p>Sleep and circadian disruptions are commonly reported by patients with neurodegenerative diseases, suggesting these may be an endophenotype of the disorders. Several mouse models of Huntington’s disease (HD) that recapitulate the disease progression and motor dysfunction of HD also exhibit sleep and circadian rhythm disruption. Of these, the strongest effects are observed in the transgenic models with multiple copies of mutant huntingtin gene. For developing treatments of the human disease, knock-in (KI) models offer advantages of genetic precision of the insertion and control of mutation copy number. Therefore, we assayed locomotor activity and immobility-defined sleep in a new model of HD with an expansion of the KI repeats (Q175). We found evidence for gene dose- and age-dependent circadian disruption in the behavior of the Q175 line. We did not see evidence for loss of cells or disruption of the molecular oscillator in the master pacemaker, the suprachiasmatic nucleus (SCN). The combination of the precise genetic targeting in the Q175 model and the observed sleep and circadian disruptions make it tractable to study the interaction of the underlying pathology of HD and the mechanisms by which the disruptions occur.</p></div