Gender differences and dose proportionality in the toxicokinetics of udenafil and its active metabolite following oral administration in rodents.

Udenafil is a long-acting oral phosphodiesterase type 5 inhibitor used to treat erectile dysfunction which may also have beneficial effects on cardiovascular diseases. Udenafil is mainly biotransformed to the active metabolite N-dealkylated udenafil via cytochrome P450 3A. The aim of this study was to investigate the gender differences and dose proportionality of the toxicokinetics of udenafil and its metabolite N-dealkylated udenafil in rodents. Udenafil was administered orally by gavage to male and female B6C3F1/N mice (100, 240, 350, and 500 mg/kg) and F344 rats (60, 120, and 240 mg/kg). Plasma concentrations of udenafil and N-dealkylated udenafil were simultaneous measured via liquid chromatography-tandem mass spectrometry. Female mice showed higher systemic exposure to udenafil than male mice, whereas female rats showed lower systemic exposure to udenafil than male rats after repeated administration at high dose. Systemic exposure to the metabolite, N-dealkylated udenafil, was lower in female than male mice and rats. A dose proportionality assessment by power model revealed a lack of dose proportionality in systemic exposure (Cmax, AUC24h and AUCinf) after administration of 100-500 mg/kg of udenafil in mice and 60-240 mg/kg in rats. This study thus demonstrates gender and species differences with regard to the toxicokinetic profiles of udenafil and its active metabolite N-dealkylated udenafil after oral administration of udenafil to mice and rats of both sexes. Our findings suggest the possibility of gender differences in the toxicokinetics of udenafil in humans and suggests that further study is needed in this cohort.

DA-6034-induced mucin secretion via Ca2+-dependent pathways through P2Y receptor stimulation.

PURPOSE: We evaluated whether DA-6034 is involved in mucin secretion via P2Y receptor activation and/or intracellular Ca2+ concentration ([Ca2+]i) change. Also, we investigated the effect of P2Y receptor inhibitors or Ca2+ chelators on the DA-6034-induced mucin secretion and [Ca2+]i increases. METHODS: Effects of DA-6034 on mucin expression in primary, cultured, conjunctival epithelial cells was studied using RT-PCR, Western blot analysis, and periodic acid-schiff (PAS) staining. To evaluate thin film layer thickness generated by mucin and fluid secretion, cells were incubated in DA-6034 with/without P2Y antagonists or extracellular/intracellular Ca2+ chelators, and were imaged with confocal microscope using Texas Red-dextran dye. In addition, DA-6034-induced Ca2+-dependent Cl- channels opening was evaluated using perforated patch clamp. Fluo-4/AM was used to measure changes in [Ca2+]i induced by DA-6034 in Ca2+-free or Ca2+-containing buffered condition, as well as P2Y antagonists. RESULTS: DA-6034 induced the expression of mucin genes, production of mucin protein, and increase of number of mucin-secreting cells. P2Y antagonists inhibited DA-6034-induced mucin and fluid secretion, which was also affected by extracellular/intracellular Ca2+ chelators. DA-6034 stimulated Cl- channel opening and [Ca2+]i elevation. Further, [Ca2+]i increases induced by DA-6034 were lacking in either P2Y antagonists or Ca2+-free buffered condition, and diminished when endoplasmic reticulum Ca2+ was depleted by cyclopiazonic acid in Ca2+-free buffered condition. CONCLUSIONS: This study demonstrated that DA-6034 has a potential to induce mucin secretion via Ca2+-dependent pathways through P2Y receptors in multilayer, cultured, human conjunctival epithelial cells.

Proof of mechanism study of a novel serotonin transporter blocker, DA-8031, using [11C]DASB positron emission tomography and in vivo microdialysis.

OBJECTIVE: To investigate the efficacy of DA-8031, a novel compound for the treatment of premature ejaculation, we measured serotonin transporter (SERT) occupancy by DA-8031, as well as DA-8031-induced changes in extracellular serotonin levels, in the rat brain using positron emission tomography (PET) and 11C-N,N-dimethyl-2-(2-amino-4-cyanophenylthio) benzylamine ([11C]DASB) and in vivo microdialysis, respectively. METHODS: [11C]DASB PET scans were performed in rats with graded doses of DA-8031 (vehicle: 10, 30, and 100 mg/kg). SERT occupancy in the midbrain was determined using binding potentials for [11C]DASB calculated by the multilinear reference tissue model. Extracellular serotonin levels were monitored in the dorsal raphe nucleus of rats after the administration of DA-8031 (10-100 mg/kg) using in vivo microdialysis. RESULTS: PET data indicated a reduction of [11C]DASB binding to SERTs in the midbrain as a function of DA-8031 dose. SERT occupancy for each DA-8031 dose (10-100 mg/kg) ranged between 31% and 84%. The drug dose required for 50% occupancy of SERT was 13.5 mg/kg in the midbrain, comparable with previous preclinical behavioral data (∼10-30 mg/kg). In vivo microdialysis showed that DA-8031 produced a dose-dependent increase in extracellular serotonin levels in the dorsal raphe nucleus (33%-81% increase for doses of 10-100 mg/kg). CONCLUSION: These preclinical data provide a proof of mechanism for DA-8031 as a novel compound of targeting the SERT for the treatment of premature ejaculation, warranting further clinical trials. They also offer insight into the optimal drug dose needed to exert therapeutic effects while minimizing adverse effects in humans.

DA-6034 Induces [Ca(2+)]i Increase in Epithelial Cells.

DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces Ca(2+) signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in Ca(2+) signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated Ca(2+)-activated Cl(-) channels (CaCCs) and increased intracellular calcium concentrations ([Ca(2+)]i) in primary cultured human conjunctival cells. DA-6034 also increased [Ca(2+)]i in mouse salivary gland cells and human corneal epithelial cells. [Ca(2+)]i increase of DA-6034 was dependent on the Ca(2+) entry from extracellular and Ca(2+) release from internal Ca(2+) stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate (IP3) pathway and lysosomal Ca(2+) stores. These results suggest that DA-6034 induces Ca(2+) signaling via extracellular Ca(2+) entry and RyRs-sensitive Ca(2+) release from internal Ca(2+) stores in epithelial cells.

Effect of DA-8031, a novel oral compound for premature ejaculation, on male rat sexual behavior.

OBJECTIVES: DA-8031 is a potent and selective serotonin transporter inhibitor developed for the treatment of premature ejaculation. The aim of the present study was to investigate the effects of DA-8031 on male sexual behavior in a rat model. METHODS: Sexual behavior was examined after an acute oral administration of 10, 30 or 100 mg/kg of DA-8031 in copulation studies with female rats. Pharmacokinetic parameters were calculated after oral administration of DA-8031 at a dose level of 30 mg/kg. RESULTS: DA-8031 treatment produced a dose-dependent increase in ejaculation latency time and showed statistical significance at 30 and 100 mg/kg dosage levels compared with the vehicle (P < 0.05). In addition, DA-8031 treatment reduced the mean number of ejaculations in a dose-dependent manner. No changes in post-ejaculatory interval, numbers of mounts, intromissions or ejaculations were observed at any dose. In pharmacokinetic study, the blood concentration of DA-8031 peaked at 0.38 ± 0.14 h after oral administration, and then rapidly declined with a half-life of 1.79 ± 0.32 h. CONCLUSIONS: Treatment with DA-8031 delays the ejaculation latency time without affecting the initiation of mounting behavior or post-ejaculatory interval in rats. Furthermore, DA-8031 is rapidly absorbed and eliminated after oral administration in rats. These preclinical findings provide a clue for the clinical testing of DA-8031 as an "on-demand" agent for premature ejaculation.

Ejaculatory responses are inhibited by a new chemical entity, DA-8031, in preclinical rodent models of ejaculation.

OBJECTIVE: To investigate the efficacy of DA-8031, a novel compound for the treatment of premature ejaculation (PE), we performed in vivo pharmacological studies using 2 preclinical animal models, electrical stimulation of sensory branch of pudendal nerve (SBPdn) and para-chloroamphetamine (PCA)-induced ejaculation model. METHODS: First of all, in electrical stimulation of an SBPdn model, an SBPdn in the pelvic canal of the spinal cord transected from rats was identified. Then an electromyogram (EMG) of the bulbospongiosus (BS) muscle was recorded during electrical stimulation of SBPdn after single intravenous (IV) dosing of DA-8031 and its reference drug, dapoxetine. In the second model, both seminal vesicle pressure (SVP) and the EMG profile of the BS muscle were recorded in PCA-induced ejaculation animals after treated with the same dosing regimen. RESULTS: Area under the curve (AUC) of the BS muscle by EMG wave exhibited a significant reduction in the DA-8031 and dapoxetine 3 mg/kg treated groups, and maximum amplitudes were also significantly decreased in DA-8031 1, 3 mg/kg and dapoxetine 3 mg/kg dose level in the SBPdN stimulation model. Consistent with these findings, in a PCA-induced ejaculation model, SVP increase was significantly inhibited from DA-8031 0.3 mg/kg dose level, and AUC of BS muscle EMG significantly decreased in the DA-8031 1, 3 mg/kg groups. CONCLUSION: The present study implied that DA-8031 contributed to an effective co-coordinated inhibition of the expulsion phase of ejaculation by modulating BS muscle activity and the emission phase through blocking SVP rise. From these findings, DA-8031 is further expected to have clinical efficacy in human studies.

Chronic administration of udenafil, a selective phosphodiesterase type 5 inhibitor, promotes erectile function recovery in an animal model of bilateral cavernous nerve crush injury.

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. METHODS: Using the CN crush injury model, 8-week-old male Sprague Dawley rats were divided into the following groups; sham-operated group, bilateral CN crush injury exposed to either no udenafil (vehicle) or udenafil (5, 20 mg/kg) daily for two different durations (4 and 8 weeks, p.o.). MAIN OUTCOME MEASURES: At both time points, CN electrical stimulation was used to assess erectile function by measuring the intracavernous pressure. The expressions of hypoxia-inducible factor 1-alpha (HIF-1α), transforming growth factor-beta (TGF-ß1), nerve growth factor (NGF), endothelin B receptor (ET(B) ), endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), and sonic hedgehog homolog (SHH) in penile tissue were examined. Immunohistochemical antibody staining was performed for NGF, eNOS, nNOS, CD31, and alpha-smooth muscle actin (α-SMA). Additionally, terminal deoxynucleotidyl transferase-mediated nick-end labeling assay was performed to quantify apoptosis and the tissue slides were stained for Masson's trichrome to assess the smooth muscle/collagen ratio. RESULTS: Udenafil improved erectile function in a dose- and time-dependent manner with the maximum erectile function recovery achieved by 20 mg/kg udenafil at an 8-week time point. CN injury increased the expression of HIF-1α, TGF-ß1, NGF, and ET(B) , however, decreased the expression of eNOS, nNOS, and SHH. Udenafil significantly suppressed these alterations. The results from the histological analyses show that udenafil markedly reduces apoptosis induced by CN injury and augments the smooth muscle/collagen ratio. CONCLUSIONS: CN injury induces significantly impaired erectile function and altered gene/protein expression. Chronic administration of udenafil preserves erectile function and has a beneficial role against the pathophysiological consequences of CN injury.

Candidate molecule for premature ejaculation, DA-8031: in vivo and in vitro characterization of DA-8031.

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. DA-8031 exhibits high affinity and selectivity to the serotonin transporter (Ki value 1.94 nM for 5-hydroxytryptamine transporter, 22 020 nM for norepinephrine transporter, and 77 679 nM for dopamine transporter) and potency to inhibit serotonin reuptake into the rat brain synaptosome in vitro (half maximal inhibitory concentration 6.52 nM for 5-hydroxytryptamine, 30.2 µM for norepinephrine, and 136.9 µM for dopamine). In the platelet serotonin uptake study, DA-8031 exhibited significant inhibition at oral doses of 10 and 30 mg/kg in a dose-dependent manner. In the sexual response studies, after oral and intravenous administration of DA-8031, ejaculation was significantly inhibited in both para-chloroamphetamine- and meta-chlorophenylpiperazine-mediated ejaculation models in rats. CONCLUSIONS: The pharmacologic profiles observed in the present study suggest the potential for DA-8031 as a therapeutic agent useful in the treatment of premature ejaculation.

Udenafil enhances the recovery of erectile function and ameliorates the pathophysiological consequences of cavernous nerve resection.

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. METHODS: Thirty male Sprague-Dawley rats (300-320 g) were used in this study. The animals were divided into three groups; group I consisted of sham-operated animals (N = 10), animals in group II underwent BCNR alone (N = 10), and animals in group III were orally treated with 10 mg/kg udenafil b.i.d. for 8 weeks following BCNR (N = 10). MAIN OUTCOME MEASURES: The expression of transforming growth factor-beta1, hypoxia-inducible factor-1 alpha, endothelial nitric oxide synthase, neuronal nitric oxide synthase, and endothelin B receptor in penile tissue was examined at gene level. Additionally, erectile function, measured by intracavernous pressure (ICP), and pathological changes in the corpus cavernosum were examined. RESULTS: While fibrosis, apoptosis, and the expression of TGF-beta1, HIF-1 alpha, and ET(B) were significantly increased, and the expression of eNOS and nNOS were significantly decreased in group II, compared with the sham-operated animals, repeated dosing of udenafil significantly ameliorated these changes. Erectile function was profoundly impaired in animals that underwent BCNR alone, and udenafil treatment significantly attenuated this impairment as measured by ICP. CONCLUSIONS: These results demonstrate that long-term administration of udenafil ameliorates penile hypoxia and fibrosis induced by cavernous nerve resection. This study also suggests the potential beneficial role of repeated dosing of udenafil in the recovery of erectile function in patients with neuronal erectile dysfunction.

The therapeutic effect of DA-6034 on ocular inflammation via suppression of MMP-9 and inflammatory cytokines and activation of the MAPK signaling pathway in an experimental dry eye model.

PURPOSE: To investigate the effect of DA-6034, 7-carboxymethyloxy-3',4',5-trimethoxy flavone, in experimentally-induced inflammatory dry eye in rabbit. In addition, to elucidate the mechanism of DA-6034, we evaluated the mitogen-activated protein kinase (MAPK) signaling pathway and transcriptional factor-kappa B (NF-kB) in corneal epithelial cells. METHODS: Rabbit lacrimal glands were injected with the T-cell mitogen concanavalin A (Con A). DA-6034 was then administered topically four times a day for six days starting 24 hr after Con A injection. Tear volume, tear function, MMP-9 and inflammatory cytokine levels in the lacrimal glands, and histological evaluation were subsequently assessed. In in vitro study, phosphorylated MAPKs (c-Jun NH2-terminal kinase (JNK) and p38 MAPK) and NF-kB were detected by enzyme-linked immunosorbent assay (ELISA) using human corneal epithelial cells. RESULTS: A single injection of Con A into the lacrimal glands induced a pronounced inflammatory response, caused elevated levels of MMP-9 and cytokines IL-8 and TGF-beta(1), and induced a decrease in tear volume and shortening of tear breakup time (TBUT). In this inflammation model of dry eye, DA-6034 clearly showed therapeutic efficacy by restoring tear function and inhibiting inflammatory responses after topical ocular application. Furthermore, DA-6034 attenuated the phosphorylation of JNK and p38 MAPK and inhibited NF-kB activation in a concentration-dependent manner in corneal epithelial cells. CONCLUSIONS: These results suggest that DA-6034 has the therapeutic effect in rabbit lacrimal gland inflammation model of dry eye and might be a potential treatment option for acute dry eye syndrome.

Effects of DA-6034, a flavonoid derivative, on mucin-like glycoprotein and ocular surface integrity in a rabbit model.

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. Corneal protection was investigated using a desiccation-induced rabbit model of dry eye syndrome. It was found that DA-6034 increased mucin-like glycoprotein levels of both conjunctival and corneal epithelial cells at concentrations above 100 microM. Using human conjunctival epithelial cells, it was demonstrated that treatment with DA-6034 (200 microM) significantly increased production of some mucins species including MUC1, MUC2, MUC4, MUC5AC, MUC5B, and MUC16. DA-6034 also significantly increased MUC5AC production from conjunctival goblet cells isolated from rats. In the rabbit desiccation model, an ophthalmic suspension containing 3% DA-6034 significantly reduced corneal damage induced by desiccation. These results suggest that DA-6034 is a good candidate for treatment of dry eye through maintaining ocular surface integrity, which might be related to mucin secretion.

Effects of DA-6034 on aqueous tear fluid secretion and conjunctival goblet cell proliferation.

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 (0.3, 1, and 3%). Moreover, time course aqueous tear volume measurement and ocular ferning test in tear fluid were performed in dry eyes of rabbits that had been given 1% atropine sulfate, topically. Altogether, tear fluid production and conjunctival goblet cell numbers were measured in dry eyes of mice that had been given topical scopolamine. RESULTS: Topical application of DA-6034 (0.3, 1, and 3%) significantly increased (P < 0.05) aqueous tear production in a concentration-dependent manner in normal rabbits. There was no change in total protein levels while glycoprotein levels were significantly increased (P < 0.05) at 3% DA-6034. The increase in aqueous tear fluid was significant (P < 0.05) and lasted for 2 h post-instillation in dry eyes of rabbits that had been given 1% atropine sulfate; 10-day repeated instillation of the drug in this model resulted in large and homogeneous fern-like tear patterns. In a mouse model, DA-6034 given as a 3% eyedrop solution significantly increased (P < 0.05) tear fluid production and conjunctival goblet cell number. CONCLUSIONS: These results suggest that DA-6034 accelerates not only tear secretion but also mucin production and may be a potential therapeutic agent for the treatment of dry eye disease.

Beneficial effects of the combination of amlodipine and losartan for lowering blood pressure in spontaneously hypertensive rats.

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). A four-week treatment of either 3 mg/kg amlodipine or 30 mg/kg losartan alone decreased the systolic blood pressure (SBP). However, their combination significantly lowered the SBP from the 3(rd) week, and there was a positive correlation between this reduction in blood pressure and the improvement in arterial endothelium-dependent relaxation. In addition, the combination therapy (1:20) decreased both the cardiac mass and left ventricular weight to a greater extent than with either amlodipine or losartan alone. The collagen content in the cardiac tissue was also significantly lower after the 4-week combination therapy (1:10). These results suggest that the combined use of amlodipine and losartan might be more effective in treating hypertension than a monotherapy.

Effect of udenafil on portal venous pressure and hepatic fibrosis in rats. A novel therapeutic option for portal hypertension.

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. The effect of udenafil on hepatic stellate cell activation and fibrotic change-related protein mRNA expression were examined. In a pharmacokinetic study, the pharmacokinetic parameters in sham-operated rats and BDL rats were compared. Three-week udenafil treatment decreased PVP by approximately 30% compared to the vehicle group. In a single oral administration study, the PVP of the udenafil treated group was lower than that of the control group throughout the experimental period. Compared to control, udenafil suppressed the expression of procollagen type I and alpha-smooth muscle actin mRNA. In the pharmacokinetic study, the AUC of udenafil in BDL rats was approximately 5 times higher than that in sham-operated rats. The results of this study suggest that udenafil has beneficial effects on portal hypertension and the effect may well be attributed to its anti-fibrogenic activity.

Why a combined intracavernosal injection with trimix and oral sildenafil is reliable therapy in the ultrasonographic evaluation of erectile dysfunction.

OBJECTIVE: To evaluate prospectively and compare the clinical response and the change in nucleotides correlating with haemodynamic changes in the cavernosal arteries after an intracavernosal injection (ICI) with vasoactive agents with or without oral sildenafil in men with erectile dysfunction (ED). PATIENTS AND METHODS: In all, 80 patients with ED were prospectively evaluated by clinical assessments, measuring nucleotides in blood plasma and haemodynamics in cavernosal arteries. All patients had colour Doppler ultrasonography (CDU) twice with an interval of 5 h. First, each patient had CDU after ICI with trimix (0.25 mL) or prostaglandin E1 (PGE1, 5 microg), and the second CDU was after ICI trimix given 1 h after oral placebo (group I), sildenafil 25 mg (group II) or 100 mg (group III) and after ICI with PGE1 at 1 h after oral placebo (group IV) or 100 mg sildenafil (group V). Levels of cGMP and cAMP in peripheral venous and penile cavernosal blood plasma were measured at 15 min after ICI. RESULTS: The mean peak systolic velocity (PSV) at 5, 10, 15 min, and resistive index at 10 min in the second CDU after ICI with trimix, were significantly increased in group III. The mean (sem) levels of cavernosal cGMP were significantly increased in group III and V, from 1130.1 (313.5) to 2056.7 (580.4) and 1017.0 (214.2) to 1905.2 (915.0) fmol/mL, respectively. cAMP was significantly increased in group V, from 9533.1 (2068.4) to 12150 (3684.2) fmol/mL. CONCLUSIONS: The haemodynamic changes and cGMP and cAMP production in the cavernosum were improved by trimix plus sildenafil more than with than PGE1 plus sildenafil or one ICI with trimix or PGE1. The results suggest that ICI with trimix and sildenafil is the best combination for a pharmacological erection test.

Gastroprotective effects of DA-6034, a new flavonoid derivative, in various gastric mucosal damage models.

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. In acetic acid-induced gastric lesions, repeated oral administration of DA-6034 exhibited a U-shape activity in ulcer healing, with the maximum and minimum inhibition being observed at 30 and 10 mg/kg/day, respectively. DA-6034 also increased the mucus content in the gel layer as well as endogenous prostaglandin E(2) synthesis. These results suggest that DA-6034 prevents gastric mucosal injury, and these gastroprotective activities appear to be due to the increase in the gastric defensive systems.

Microarray analysis of gene expression profile in the corpus cavernosum of hypercholesterolemic rats after chronic treatment with PDE5 inhibitor.

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). Sixteen male Sprague-Dawley rats were fed 2% cholesterol diet for 5 months. Half of them were orally treated with Udenafil (20 mg/kg/day) simultaneously. Eight age-matched rats fed normal diet were served as normal control. RNA was extracted from corpus cavernosum and microarray analysis was performed. Decreased erectile responses and hypercholesterolemia were observed in hypercholesterolemic control group. In microarray analysis, 122 candidate genes were noted to be altered based on the magnitude of expression changes, which includes 44 down-regulated and 78 up-regulated genes compared with the age-matched normal controls. These changes were, however, significantly attenuated by treatment with Udenafil. Out of the 78 up-regulated genes, 8 genes were significantly decreased by the chronic treatment with Udenafil. The altered genes were cytochrome oxidase biogenesis protein OXA1, skeletal muscle myosin heavy chain, lipophilin, fast skeletal muscle isoforms beta/alpha, myosin light chain 3, cytochrome c oxidase, adipocyte fatty acid binding protein and one EST gene. In contrast, among the 44 down-regulated genes, Kruppel-like factor 5 and cyclin D1 genes were increased after the Udenafil treatment. These results provide the molecular basis for understanding the pathogenesis of hypercholesterolemia-related ED and offer clues on determining the underlying action mechanism of a PDE5 inhibitor.

Inhibitory effect of DA-9201, an extract of Oryza sativa L., on airway inflammation and bronchial hyperresponsiveness in mouse asthma model.

Asthma is one of the major public health problems worldwide and the morbidity and mortality of asthma has increased in the past two decades. Accumulating data suggest that unnecessary immune responses and inflammation should be suppressed to treat asthma. The purpose of this study is to investigate the anti-asthmatic effects of DA-9201, an ethanolic extract of black rice (Oryza sativa L. var japonica), on an ovalbumin (OVA)-induced mouse model of asthma. Balb/c mice immunized with OVA were administered with DA-9201 (30, 100 or 300 mg/kg, p.o.) or dexamethasone (3 mg/kg, p.o.) and challenged with 1% aerosolized OVA for 30 min. The effects on airway inflammation, airway hyperresponsiveness (AHR), antibody profiles and cytokines were evaluated. DA-9201 treatment significantly reduced the number of eosinophils in bronchoalveolar lavage fluid (BALF) and ameliorated the AHR. Lung histological features also showed that DA-9201 reduced airway inflammation. Furthermore, DA-9201 treatment decreased IFN-gamma as well as IL-4, IL-5 and IL-13 levels in the supernatant of cultured splenocytes, and suppressed the level of OVA-specific IgG, IgG2a, IgG1 and total IgE in plasma. DA-9201 showed anti-asthmatic effects by suppressing unnecessary immune responses, airway inflammation, eosinophilia, AHR and IgE level. These results suggest DA-9201 might be beneficial for the treatment of asthma.

Erectile potentials of a new phosphodiesterase type 5 inhibitor, DA-8159, in diet-induced obese rats.

AIM: To examine the changes in the erectile function in diet-induced obese rats and investigate the oral efficacy of DA-8159, a new phosphodiesterase type 5 (PDE5) inhibitor, on penile erection in obese rats. METHODS: The rats were fed a high-energy diet for 12 weeks and divided into three groups: an obesity-resistant (OR) control group, an obesity-prone (OP) control group, and an OP-DA-8159 treatment (DA-8159) group. The electrostimulation-induced erectile responses were measured in all groups. The body weight, plasma cholesterol, triglyceride and glucose levels were also measured. RESULTS: In the OP control group, the maximum intracavernous pressure (ICP) and ICP/blood pressure (ICP/BP) ratio after electric stimulation were significantly lower than those in OR control group. The corresponding area under the curve (AUC) of the ICP/BP ratio, the detumescence time and the baseline cavernous pressure were also lower than those in the OR control group, but this difference was not significant. The body weight gain, plasma cholesterol and triglyceride level in the OP group were significantly higher than those in the OR group. After administering the DA-8159, a significant increase in the maximum ICP and the ICP/BP ratio were observed. The corresponding AUCs in the DA-8159 group were also higher than those in the two control groups. Furthermore, the detumescence time was significantly prolonged after treatment with DA-8159. CONCLUSION: These results demonstrate that diet-induced obesity affects the erectile function in rats and these erectile dysfunction (ED) can be improved by the treatment with DA-8159, indicating DA-8159 might be a treatment option for ED associated with obesity.

Effect of Oryza sativa extract on the progression of airway inflammation and remodeling in an experimental animal model of asthma.

Airway inflammation and remodeling in chronic asthma are characterized by airway eosinophilia, hyperplasia of smooth muscle and goblet cells, and subepithelial fibrosis. The present study was undertaken to evaluate the effects of DA-9201, an ethanolic extract of black rice (Oryza sativa L.), on airway inflammation and remodeling in a murine model of chronic asthma. BALB/c mice sensitized to ovalbumin (OVA) were chronically challenged with aerosolized OVA for 6 weeks. DA-9201 (30, 100, or 300 mg/kg) or dexamethasone (3 mg/kg) was orally administered during the last 4 and 2 weeks, respectively. Airway inflammation, lung pathology by histomorphometry and immunohistochemistry, IgE level and Th2 cytokines were evaluated. The OVA-treated mice showed extensive eosinophilia, chronic inflammatory responses and characteristics of airway remodeling including subepithelial fibrosis, smooth muscle hypertrophy, and goblet cell hyperplasia. As compared to the OVA-treated control group, treatment with DA-9201 resulted in significant reductions in the accumulation of eosinophils in peribronchial areas, chronic pulmonary inflammation and progression of airway remodeling. Furthermore, DA-9201 significantly reduced total serum and BALF IgE levels and Th2 cytokines. These results indicate that DA-9201 may play an important role in attenuating the progressing of airway inflammation and remodeling and suggest the potential benefits of DA-9201 in prevention or treatment of asthma.