Effects of DA-9801 on the inflammation and apoptosis induced by angiotensin II in human dermal microvascular endothelial cells.

DA-9801, a plant-based drug used for the treatment of diabetic neuropathy, is known to improve angiotensin II (Ang II)-induced vascular endothelial cell dysfunction. However, the underlying mechanism is not fully understood. We aimed to determine whether the protective effect of DA-9801 against Ang II-induced endothelial cell dysfunction was mediated via inhibition of endothelial cell inflammation and apoptosis.

Novel botanical drug DA-9803 prevents deficits in Alzheimer's mouse models.

Background: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by deposition of amyloid plaques and disruption of neural circuitry, leading to cognitive decline. Animal models of AD deposit senile plaques and exhibit structural and functional deficits in neurons and neural networks. An effective treatment would prevent or restore these deficits, including calcium dyshomeostasis observed with in-vivo imaging.

Prevention and treatment effect of evogliptin on hepatic steatosis in high-fat-fed animal models.

Dipeptidyl peptidase 4 (DPP4) is an adipokine that interrupts insulin signaling. The resulting insulin resistance exacerbates hepatic steatosis. We previously reported that the novel DPP4 inhibitor evogliptin improves insulin resistance.

New reliable scoring system, Toyama mouse score, to evaluate locomotor function following spinal cord injury in mice.

Background: Among the variety of methods used to evaluate locomotor function following a spinal cord injury (SCI), the Basso Mouse Scale score (BMS) has been widely used for mice. However, the BMS mainly focuses on hindlimb movement rather than on graded changes in body support ability. In addition, some of the scoring methods include double or triple criteria within a single score, which likely leads to an increase in the deviation within the data.

DA-1229, a novel and potent DPP4 inhibitor, improves insulin resistance and delays the onset of diabetes.

Aim: To characterize the pharmacodynamic profile of DA-1229, a novel dipeptidyl peptidase (DPP) 4 inhibitor.

Main Methods: Enzyme inhibition assays against DPP4, DPP8 and DPP9. Antidiabetic effects of DA-1229 in HF-DIO mice and young db/db mice.

Discovery of DA-1229: a potent, long acting dipeptidyl peptidase-4 inhibitor for the treatment of type 2 diabetes.

A series of β-amino amide containing substituted piperazine-2-one derivatives was synthesized and evaluated as inhibitors of dipeptidyl pepdidase-4 (DPP-4) for the treatment of type 2 diabetes. As results of intensive SAR study of the series, (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl)-butanoyl]-3-(t-butoxymethyl)-piperazin-2-one (DA-1229) displayed potent DPP-4 inhibition pattern in several animal models, was selected for clinical development.

A novel dipeptidyl peptidase IV inhibitor DA-1229 ameliorates streptozotocin-induced diabetes by increasing β-cell replication and neogenesis.

We studied the effect of a novel dipeptidyl peptidase IV (DPP IV) inhibitor, DA-1229, on blood glucose profile and pancreatic β-cell mass in established diabetes after streptozotocin (STZ) treatment. Mice that developed diabetes after administration of STZ 100mg/kg were treated with DA-1229 for 13 weeks. DA-1229 significantly reduced plasma DPP IV activity, and enhanced glucagon-like peptide 1 (GLP-1) levels.

PAM-1616, a selective peroxisome proliferator-activated receptor γ modulator with preserved anti-diabetic efficacy and reduced adverse effects.

Peroxisome proliferator-activated receptor (PPAR) γ is known to be a key regulator of insulin resistance. PAM-1616 is a novel, non-thiazolidinedione small molecule compound synthesized in Dong-A Research Center. In this study, we characterized the pharmacological and safety profiles of PAM-1616 as a selective PPARγ modulator.

PAR-1622 is a selective peroxisome proliferator-activated receptor gamma partial activator with preserved antidiabetic efficacy and broader safety profile for fluid retention.

Peroxisome proliferator-activated receptor (PPAR) gamma is known to be a key regulator of insulin resistance. PAR-1622 is a novel small molecule compound synthesized in Dong-A research center. In this study, we characterized the pharmacological profiles of PAR-1622, a selective partial activator of PPARgamma.

Lamotrigine prevents MK801-induced alterations in early growth response factor-1 mRNA levels and immunoreactivity in the rat brain.

MK801 (dizocilpine) induces selective neurotoxic effects in the retrosplenial cortex, ranging from neuronal vacuolization to irreversible neurodegeneration depending on the dose administered. Although lamotrigine prevents MK801-induced neuronal vacuolization in the retrosplenial cortex 4 h after injection, it is not clear whether lamotrigine attenuates the subsequent neurodegeneration that occurs 3-4 days later. Because early growth response factor-1 (egr-1) plays a key role in neurodegeneration and its expression is induced in the retrosplenial cortex following MK801 treatment, it is possible that lamotrigine may attenuate MK801-induced neurodegeneration via inhibition of egr-1 expression in the retrosplenial cortex.

Effects of repeated citalopram treatments on chronic mild stress-induced growth associated protein-43 mRNA expression in rat hippocampus.

Although growth associated protein-43 (GAP-43) is known to play a significant role in the regulation of axonal growth and the formation of new neuronal connections in the hippocampus, there is only a few studies on the effects of acute stress on GAP-43 mRNA expression in the hippocampus. Moreover, the effects of repeated citalopram treatment on chronic mild stress (CMS)-induced changes in GAP-43 mRNA expression in the hippocampus have not been explored before. To explore this question, male rats were exposed to acute immobilization stress or CMS.

Chronic mild stress decreases survival, but not proliferation, of new-born cells in adult rat hippocampus.

New-born cells continue to proliferate and survive to become mature granule cells in adult rat hippocampus. Although this process, known as neurogenesis, is inhibited by acute stress, it is not clear whether chronic stress affects neurogenesis. To determine whether chronic mild stress (CMS) influences neurogenesis in the adult rat hippocampus, male Sprague-Dawley rats were exposed to CMS and administered bromodeoxyuridine (BrdU) before or after CMS to observe the survival/differentiation or proliferation of new-born cells, respectively.

Effects of repeated tianeptine treatment on CRF mRNA expression in non-stressed and chronic mild stress-exposed rats.

Accumulating evidence suggests that dysregulation of corticotropin-releasing factor (CRF) may play a role in depression and that this dysregulation may be corrected by antidepressant drug treatment. Here, we examined whether chronic mild stress (CMS) alters CRF mRNA levels in stress-related brain areas including the bed nucleus of the stria terminalis (BNST) and the central nucleus of amygdala (CeA), and whether repeated tianeptine treatment can attenuate CMS-induced changes in CRF mRNA levels. Male rats were exposed to CMS for 19 days, and control animals were subjected to brief handling.

Doxapram increases corticotropin-releasing factor immunoreactivity and mRNA expression in the rat central nucleus of the amygdala.

Doxapram causes panic anxiety in humans. To determine whether doxapram alters corticotropin-releasing factor (CRF) expression in the central nucleus of the amygdala (CeA), paraventricular nucleus of hypothalamus (PVN), or bed nucleus of the stria terminalis (BNST), we used immunohistochemistry to measure CRF peptide in these brain areas after doxapram injection. Doxapram injection significantly increased CRF-like immunoreactivity (CRF-IR) within the CeA, but not in the BNST or PVN, and this increase was significant 2h after injection.

Stress-induced decrease of granule cell proliferation in adult rat hippocampus: assessment of granule cell proliferation using high doses of bromodeoxyuridine before and after restraint stress.

Stress is known to inhibit granule cell proliferation in the hippocampus. However, recent studies suggest that the commonly used dose of bromodeoxyuridine (BrdU) is insufficient to label all fractions of granule cells. Furthermore, stress-induced changes in BrdU availability may influence the labeling of newly born cells.