Publications by authors named "Byoung-Ok Ahn"

This study investigated the effects of acetyl-L-carnitine (ALC) in secondarily-induced cerebral chronic ischemia models using rats with permanent ligation of bilateral common carotid arteries (BCCL) and spontaneously hypertensive rats (SHR). Additionally, we used normal aged rats as a primary dementia model. Chronic ALC administration at 100 mg/kg (p.

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Background And Aim: 7-Carboxymethyloxy-3',4',5-trimethoxy flavone (DA6034), a synthetic derivative of eupatilin, has a protective effect on gastric mucosa against various ulcerogens, and is currently in the phase III clinical trial in the treatment of peptic ulcer disease. Cell migration and/or growth plays a role in the repair process of gastric ulcer, so this study investigated the effect of DA6034 on the movement and proliferation of gastric epithelial cells and its associated signaling pathway.

Methods: The migration of AGS or SNU484 human gastric epithelial cells was shown by scratch-induced wound healing and transwell assays, and the proliferation of the cells was assessed by FACS and proliferation assays.

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Introduction: Preservation of the cavernous nerves (CNs) during radical prostatectomy is crucial for the patient's erectile function. Despite advances in operative technique, the majority of men report compromised erectile function postprostatectomy or complete loss of potency due to CN trauma even with nerve-sparing modifications.

Aim:   This study was designed to investigate whether repeated dosing of udenafil, a phosphodiesterase type 5 inhibitor, helps to improve erectile function after CN injury.

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Objectives: To evaluate the efficacy of DA-8031 against premature ejaculation, we performed in vitro and in vivo pharmacologic studies.

Methods: We used a monoamine transporter binding affinity assay, receptor binding affinity assay, monoamine reuptake inhibition assay, and serotonin uptake inhibition assay in platelets and chemically induced ejaculation models in rats.

Results: The present study reports on the pharmacologic profile of the putative antipremature ejaculation drug, DA-8031.

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Introduction: Radical prostatectomy is the treatment of choice for prostate cancer patients. Despite the introduction of nerve-sparing surgical techniques, its success is not entirely guaranteed and the majority of patients report compromised erectile function following surgical procedures.

Aim: This study was performed to investigate the effect of repeated dosing of udenafil, a novel phosphodiesterase type 5 inhibitor, on penile hypoxia and fibrosis induced by bilateral cavernous nerve resection (BCNR) in rats.

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The purpose of this study was to investigate the therapeutic efficacy of udenafil (CAS 268203-93-6), a phosphodiesterase type 5 (PDE5) inhibitor, on bile duct ligation (BDL)-induced portal hypertension. Udenafil was given orally to rats at dose levels of 1, 5 or 25 mg/kg/day for 3 weeks in order to examine the chronic effect on portal venous pressure (PVP). Udenafil was also given orally to investigate the sequential change of PVP in BDL animals.

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This study was designed to assess whether DA-6034 (7-carboxymethyloxy-3',4',5-trimethoxy flavone monohydrate), a new synthetic derivative of eupatilin, increases secretion of mucin-like glycoprotein and some mucins species in conjunctiva and cornea, and contributes to the preservation of ocular surface integrity. Human conjunctival and corneal epithelial cells were incubated with DA-6034 (1-250 microM). To investigate mucin secreting activity more directly, isolated rat conjunctival goblet cells were also used.

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Purpose: This study was conducted to evaluate the effect of DA-6034, a potent secretagogue, on aqueous tear fluid secretion and its quality in normal rabbit. We also evaluated, in animal models of experimentally induced dry eye disease, its effectiveness over time to stimulate aqueous tear production by ocular ferning test and goblet cell proliferation.

Methods: Aqueous tear production, total protein levels, and glycoprotein levels in normal rabbits were evaluated after topical application of DA-6034 (0.

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A combination of antihypertensive agents can better control blood pressure and reduce the number and severity of side effects than a monotherapy. Since both CCBs (calcium channel blockers) and ARBs (angiotensin II receptor type-1 blockers) are current and effective antihypertensive drugs, this study assessed the synergistic antihypertensive effects as well as the optimal combination ratio of these two drugs. Amlodipine (3 mg/kg) or losartan (30 mg/kg) alone or a combination of each drug at a ratio 1:10 and 1:20 was administered orally to spontaneously hypertensive rats (SHR).

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This study evaluated the gastroprotective activity of DA-6034 against various ulcerogens including ethanol, aspirin, indomethacin, stress, and acetic acid. The basic mechanisms of DA-6034 as a defensive factor such as mucus secretion and endogenous prostaglandin E(2) synthesis were determined. Rats with gastric lesions induced by ethanol-HCl, aspirin, indomethacin, and stress that had been pretreated with DA-6034 orally showed a statistically significant decrease or decreasing tendency of the gastric lesion.

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Gene expression changes in the corpus cavernosum of hypercholesterolemic rats were not fully assessed, which were not previously known to be associated with hypercholesterolemia-related erectile dysfunction (ED). To provide molecular insight into pathophysiology of hypercholesterolemia-related ED and to investigate the effects of Udenafil, a phosphodiesterase type 5 (PDE5) inhibitor, on gene expression, we performed microarray gene expression analysis via gene discovery methods using GenoCheck platinum cDNA chip (Ansan, S. Korea).

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Hypertension is a common problem in elderly patients, which usually requires chronic therapy under various physiological conditions including low gastric acidity (hypo- or anacidity). This study investigated a new salt type of amlodipine (CAS 88150-42-9) on blood pressure and hypertension-related complications in stroke-prone spontaneously hypertensive rats (SHR-SP). Amlodipine orotate was prepared by reacting orotic acid and amlodipine to increase the dissolution rate at higher gastric pH conditions.

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Aim: To examine the effect of DA-9601, a new gastroprotective agent, on the vulnerability of ethanol-treated rat's stomach to naproxen (NAP).

Methods: Male Sprague-Dawley rats were pretreated with 1 mL of 50% ethanol twice a day for 5 d and then NAP (50 mg/kg) was administered. DA-9601 was administered 1 h before NAP.

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Aim: To investigate the therapeutic effects of DA-9601 on sodium taurocholate (TCA)-induced chronic reflux gastritis in SD rats.

Methods: In this study, we have investigated the therapeutic effects of DA-9601 on chronic erosive and atrophic gastritis induced by 6 mo of TCA administration (5 mmol/L in drinking water) in SD rats.

Results: Four weeks of DA-9601 administration (0.

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Nuclear factor kappa B (NF-kappaB) regulates the expression of multiple cytokines, chemokines, and cell adhesion molecules that are involved in the pathogenesis of asthma. We investigated the anti-asthmatic effects and the mechanism of action of DA-9201, an extract of the black rice, in a mouse model of asthma. Mice immunized with ovalbumin (OVA) were administered with DA-9201 (30, 100 or 300 mg/kg) or dexamethasone (DEXA, 3 mg/kg) for 2 weeks and challenged with aerosolized OVA during the last 3 days.

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The vascular changes associated with early diabetic retinopathy, which include the formation of microaneurysms and acellular capillaries, vessel dilation, vascular endothelial growth factor expression, were investigated experimentally in streptozotocin-induced diabetic rats treated with antioxidants: troxerutin (trihydroxy-ethylrutoside, CAS 7085-55-4), Vaccinium myrtillus, and calcium dobesilate (hydroquinone calcium sulfonate, CAS 20123-80-2). The development and progression of retinopathy was followed using fundus photography. After 3 months, the rats were sacrificed and half of the eyes were prepared for neovascularization analysis, and the other half were used for VEGF (vascular endothelial growth factor) analysis.

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This study was conducted to determine if the long-term administration of the phosphodiesterase type 5 (PDE 5) inhibitor, DA-8159, to diabetic rats can ameliorate the development of erectile dysfunction (ED) and endothelial dysfunction. After inducing diabetes with streptozotocin, DA-8159 was orally administered at a dose of 3 mg/kg or 10 mg/kg for 8 weeks. To examine the effect on erectile response, electrostimulation of the cavernous nerve with the parameters of 3 V, 5 ms, 5 Hz or 10 Hz, was performed to measure the intracavernous pressure (ICP) and mean arterial pressure (MAP).

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Peptic ulcer and gastroesophageal reflux are common acid-peptic related diseases. The pathophysiology of peptic ulcer disease has been centered on an imbalance between aggressive and defensive factors. This study was conducted to examine whether the combined use of omeprazole (CAS 73590-58-6), a proton pump inhibitor, and DA-9601, a novel anti-ulcer formulation of the extract of Artemisia asiatica Nakai, has synergistic effects on various peptic ulcers and gastroesophageal reflux diseases in animal models.

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Background/aim: Oxygen free radicals (OFRs) mediate an important step in the initiation of experimental acute pancreatitis and several clinical findings suggested the possible contribution of OFRs to the pathogenesis of pancreatic fibrosis. So far, there are no studies which reporting potential role of OFRs in development of chronic pancreatitis with the prevention with antioxidants. This study was aimed to establish the mice model of chronic fibrosing pancreatitis and to prove the involvement of OFRs in chronic pancreatitis with fibrosis.

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Objectives: To assess the efficacy of the phosphodiesterase 5 inhibitor, DA-8159, in selective serotonin reuptake inhibitor (SSRI)-induced rat erectile dysfunction model by measuring intracavernous pressure (ICP).

Methods: Erectile dysfunction was induced by oral administration of either paroxetine or fluoxetine in rats. The changes in ICP and mean arterial pressure (MAP) were simultaneously recorded throughout electrostimulation of the cavernous nerve with 2 or 10 Hz after intravenous injection of DA-8159 (1 mg/kg).

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Aim: To determine the efficacy and safety of DA-9601 on erosive gastritis versus cetraxate as a standard drug by gastrointestinal endoscopy.

Methods: Five hundred and twelve patients with erosive gastritis were divided into three groups. The groups received 180 mg or 360 mg of DA-9601, or 600 mg of cetraxate (Neuer) t.

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In this study, we evaluated the effects of oral administration of DA-8159, a selective phosphodiesterase-5 inhibitor, on the development of pulmonary hypertension (PH) induced by monocrotaline (MCT). Rats were administered either MCT (60 mg/kg) or saline. MCT-treated rats were divided into three groups and received orally administered vehicle, or 1 mg/kg or 5 mg/kg of DA-8159, twice a day for twenty-one days.

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The exposure of gastric mucosa to ethanol produces pathological changes such as inflammatory process, hemorrhagic erosions, even acute ulcers. The gastric mucosal lesions accompanied by a significant decrease of gastric blood flow and increase of reactive oxygen species (ROS) implicate a role of xanthine oxidase in ethanol-induced gastric hemorrhagic erosions. DA-9601, a novel antipeptic formulation of extracts of Artemisia asiatica Nakai, was studied for its inhibitory effect on gastric xanthine oxidase activity and type conversion of the enzyme that has a profound role in free radical generation.

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Objectives: DA-8159 is a pyrazolopyrimidinone derivative showing potent and selective phosphodiesterase 5 (PDE5) inhibition. In the previous study, DA-8159 induced a dose-dependent increase in the intracavernous pressure (ICP) in anaesthetized dogs. The aim of this study was to investigate the effects of DA-8159 on penile erection in conscious and acute spinal cord injured (ASCI) rabbits.

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Background/aims: Oxidative stress is one of the important underlying mechanisms of hepatic fibrosis. DA-9601, the ethanol extracts of Artemisia asiatica, has been reported to possess strong antioxidative and cytoprotective actions. We tried to evaluate whether antioxidant can ameliorate dimethylnitrosamine (DMN)-induced hepatic fibrosis.

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