• Archives of Pharmacal Research
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• v.12 no.4
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• pp.276-281
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• 1989

Selective inhibition of seven new PDE inhibitors on cyclic nucleotide PDE isozymes was investigated. Three PDE isozymes (PDE I, II and III) of guinea pig left ventricular muscles were used. All tested agents inhibited cyclic AMP hydrolysis by PDE III IN A concentration-dependent manner. Some agents represented more potent and selective inhibitory effect on PDE III than that of imazodan.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.615-624
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• 2003

Vascular smooth muscle relaxation is modulated by an increase in cGMP subsequent to nitric oxide (NO) production by endothelial cells. The effects of cAMP and cGMP phosphodiesterase (PDE) inhibitors were investigated in phenylephrine-precontracted rat aorta rings by using the specific inhibitors of PDE I, III, IV and V as relaxing agents (calmodulin-activated PDE inhibitors, IBMX and $W_7$, type I; cAMP-specific PDE inhibitors, milrinone, type IV; Ro 20-1724, type III and cGMP-specific PDE inhibitor, zaprinast, type V). All the PDE inhibitors produced a concentration-dependent relaxation in the ring with intact endothelium (+E). Except for milrinone, all the PDE inhibitors-induced relaxations were inhibited by removal of extracellular $Ca^{2+}$, $N^G$-nitro-L-arginine, $N^G$-nitro-L-arginine methyl ester, methylene blue (MS) or nifedipine. The specific PDE I and PDE IV inhibitors both produced endothelium-independent relaxations which were inhibited by MS in -E rings. However, zaprinast had no effect in -E rings. Except for milrinone, sodium nitroprusside (a NO donor)-induced relaxation was significantly augmented by all PDE inhibitors in +E rings. The results suggest that I) the vasorelaxant properties of IBMX, $W_7$, Ro 20-1724 and zaprinast are dependent on endothelium or on interaction with $Ca^{2+}$ regulation, 2) each PDE is differently distributed in vascular tissues (endothelial and smooth muscle cells), 3) the vasodilations of PDE inhibitors are due to the increase of cAMP and cGMP formation through inhibition of cAMP- and cGMP-PDE and 4) the vasodilation action of milrinone does not involve in endothelial-cyclic nucleotide system.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.873-878
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• 2002

OA-8159, a new Phosphodiesterase (PDE) 5 inhibitor, has exhibited potent erectogenic potential in a penile erection test in rats and anesthetized dogs. In this study, we investigated the mechanism of its erectogenic activity by measuring the activity of OA-8159 against a various PDE isozymes and assessing cGMP and cAMP formation in a rabbit corpus cavernosum in vitro. DA-8159 inhibited the PDE 5 activity in rabbit and human platelets, which the $IC_{50}$ was 5.84$\pm$1.70 nM and 8.25$\pm$2.90 nM, respectively. The $IC_{50}$ of DA-8159 on PDE 1, PDE2, PDE 3 and PDE 6 were 870$\pm$57.4 nM, $101\pm$5 $\mu$M, 52.0$\pm$3.53 $\mu$M and 53.3$\pm$2.47 nM, respectively. This suggests that DA-8159 is a potent, highly selective, competitive inhibitor of PDE 5-catalyzed cGMP hydrolysis. The rates of cGMP hydrolysis catalyzed by human platelets-derived PDE 5 as a function of the cGMP concentration (5~100 nM) and two-fixed DA-8159 concentration (11.3 and 18.8 nM) were investigated in order to characterize the mode of PDE 5 inhibition by DA-8159. DA-8159 increased the apparent 4K_{m}$ value for cGMP hydrolysis but had no effect on the apparent $V_{max}$, indicating a competitive mode of inhibition. DA-8159 increased the cGMP concentrations in the rabbit corpus cavernosum dose dependently. In the presence of sodium nitroprusside (SNP), DA-8159 significantly sti\mulated the accu\mulation of cGMP when compared to the control level. This indicated that the enhancement of a penile erection by DA-8159 involved the relaxation of the cavernosal smooth \muscle by NO-sti\mulated cGMP accu\mulation. In conclusion, DA-8159 is a selective inhibitor of PDE 5-catalyzed cGMP hydrolysis and the enhancement of a penile erection by DA-8159 is mediated by the relaxation of the cavernosal smooth \muscle by the NO-sti\mulated cGMP accu\mulation.

• Journal of Life Science
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• v.26 no.12
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• pp.1355-1359
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• 2016

Human bone marrow mesenchymal stem cells (hBM-MSCs) can differentiate into various cell types including osteoblasts, adipocytes, chondrocytes, and myocytes. Previous studies, including our own, have shown that MSCs can also differentiate into neuron-like cells. However, their rate of neuronal differentiation is not sufficient for application to stem cell therapy, which requires well-defined cell types. For this purpose, we first examined the expression of neuronal lineage markers (GFAP, MAP-2, KCNH1, Nestin, NF-M, and Tuj-1) by real-time PCR, western blot, and immunocytochemical staining. The expressions of the astrocyte marker GFAP and neuronal markers NF-M and Tuj-1 increased in neuronal differentiated MSCs (dMSCs). To improve the neuronal differentiation efficiency, PDE4, an important signaling intermediator in the progression of neuronal differentiation, was modulated using well-known inhibitors such as rolipram or resveratrol and then differentiated into neuronal cells (Roli- or RSV-dMSCs). The expressions of NF-M, Tuj-1 were increased while that of GFAP decreased in Roli- and RSV-dMSCs, which were examined by real-time PCR, western blot, and immunocytochemical staining. From these experiments, we have found that the neuronal differentiation efficiency can be ameliorated by the modulation of PDE4 activity.

• Korean Journal of Pharmacognosy
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• v.45 no.3
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• pp.268-274
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• 2014

The aim of this study is to explore the potent phosphodiesterase 4 and 7 inhibitor from various herbal medicines for atopy treatment. In this study, 51 kinds of each herbal medicine, which were extracted with ethanol, was carried out the screening of PDE 4 and 7 inhibition using enzyme inhibitory assay. Of these, 8 species of herbal medicines, Rubus coreanus, Duchesnea chrysantha, Alisma orientale, Rehmannia glutinosa, Angelica dahurica, Thuja orientalis, Astragalus membranaceus and Perilla frutescens were screened as potential inhibitor against PDE 4 and 7. Among 8 species, Duchesnea chrysantha showed poteinial anti-atopic effect on DNCB-induced atopic model. Duchesnea chrysantha extract decreased serum IgE and histamine release significantly.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.81-81
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• 2018

The present study was investigated on in vitro anti-obesity effect of 4-hydroxybenzyl alcohol from Cudrania tricuspidata. We isolated various compounds from Cudrania tricuspidata. Among these compounds, anti-obesity effects of 4-hydroxybenzyl alcohol was examined by lipase activity assay, cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase type IV (PDE4) activity assay, and citrate synthase activity assay. 4-hydroxybenzyl alcohol and Cudrania tricuspidata extracts inhibited the enzymatic activities of lipase, PDE4, and citrate synthase. Lipase is known to mediate the hydrolysis of triacylglycerol in adipose tissue and cholesterol esters in other tissue or cells. Also, PDE4 hydrolyses cAMP, a crucial secondary messenger for in metabolic pathways including glucose and lipid metabolism, lipolysis, and thermogenic function. 4-hydroxybenzyl alcohol and Cudrania tricuspidata extracts induced the inhibitory effect against each enzymatic activity on several specific substrates as observed by detection at 405 or 412 nm. These findings might be attributable to the inhibition of adipogenesis, and partial prevention of obesity. In conclusion, these results show that 4-hydroxybenzyl alcohol and Cudrania tricuspidata may be a critical candidate as a natural anti-obesity source.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.332-337
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• 2000

This study describes the synthesis, in vitro evaluation and molecular modeling study of novel compounds for the inhibition of TNF-$\alpha$production, Among these compounds, 2-[3-(cyclopentyloxy)-4-methoxyphenyl]-1-isoindolinone (9) was selected as a lead compound and its pyridine derivative 10 was more potent in activity and safer than rolipram.

• The Journal of Internal Korean Medicine
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• v.37 no.4
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• pp.591-600
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• 2016

Objective: This study aimed to examine the relaxation effects and underlying mechanisms of Cynomorii herba (CH) extract in isolated rabbit corpus cavernous tissues.Methods: We experimented with CH extract (0.01-3.0 mg/mL). Nω-nitro-L-arginine (L-NNA) was experimented before the CH extract to contracted strips induced by phenylephrine (PE, 1 μM)and compared with nonexperimented. In addition, we experimented with calcium chloride (Ca²⁺, 1 mM) after pretreatment of the CH extract in Ca²⁺-free Krebs-Ringer solution to contracted strips induced by PE. The cell viability and nitric oxide (NO) concentration of human umbilical vein endothelial cells (HUVECs) were measured by an methylthiazol-2-yl-2, 5-diphenyl tetrazoliumbromide (MTT) assay and Griess reagent system. The ratio of smooth muscles to collagen fibers, in addition to eNOS- and PDE-5-positive reactions, was examined by histochemical and immunohistochemical staining.Results: The CH extract significantly induced the relaxation of the cavernous strips, and the pretreatment with L-NNA inhibited CH extract-induced relaxation. The L-NNA pretreatment reduced the increased contraction induced by the addition of Ca²⁺in Ca²⁺-free solution. Furthermore, the NO concentration of the HUVECs increased. When the CH extract was applied to the corpus cavernosum of the penis (CCP) of Sprague Dawley rats, the ratio of smooth muscles to collagen fibers by PE and the formation of eNOS around the helicine artery increased. However, the CH extract treatment decreased PDE-5 positive reactions.Conclusions: These results show that the relaxation effects induced by the CH extract are associated with the suppression of the influx of extracellular Ca²⁺ via the production of NO and eNOS and inhibition of PDE-5.

• Biomolecules & Therapeutics
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• v.28 no.4
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• pp.328-336
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• 2020

Diabetes mellitus affects the colonic motility developing gastrointestinal symptoms, such as constipation. The aim of the study was to examine the role of intracellular signaling pathways contributing to colonic dysmotility in diabetes mellitus. To generate diabetes mellitus, the rats were injected by a single high dose of streptozotocin (65 mg/kg) intraperitoneally. The proximal colons from both normal and diabetic rats were contracted by applying an electrical field stimulation with pulse voltage of 40 V in amplitude and pulse duration of 1 ms at frequencies of 1, 2, 4, and 6 Hz. The muscle strips from both normal rats and rats with diabetes mellitus were pretreated with different antagonists and inhibitors. Rats with diabetes mellitus had lower motility than the control group. There were significant differences in the percentage of inhibition of contraction between normal rats and rats with diabetes mellitus after the incubation of tetrodotoxin (neuronal blocker), atropine (muscarinic receptor antagonist), prazosin (α₁ adrenergic receptor antagonist), DPCPX (adenosine A1 receptor antagonist), verapamil (L-type Ca²⁺ channel blocker), U73122 (PLC inhibitor), ML-9 (MLCK inhibitor), udenafil (PDE₅ inhibitor), and methylene blue (guanylate cyclase inhibitor). The protein expression of p-MLC and PDE₅ were decreased in the diabetic group compared to the normal group. These results showed that the reduced colonic contractility resulted from the impaired neuronal conduction and decreased muscarinic receptor sensitivity, which resulted in decreased phosphorylation of MLC via MLCK, and cGMP activity through PDE₅.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1724-1731
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• 2009

This study was aimed to investigate the effect of phyto-extract fermented mixture (MP119) on the male sexual functions. The MP119 was evaluated for anti-impotency and anti-hypertensive effects via ACE (angiotensin converting enzyme) or PDE (phosphodiesterase) inhibition assay. $IC_{50}$ values of MP119 against ACE and PDE were 241.3${\pm}$35.5 ppm and 372.2${\pm}$33.8 ppm, respectively. To investigate the effect of testosterone expression by MP119, we performed cell media test using mouse Leydig-derived TM3 cells. Production of testosterone in TM3 cell was increased by MP119. Also, NO (nitric oxide) production of HUVEC (human umbilical vein endothelial cell) was increased when MP119 was added to the cultures. Forty male ICR mice were divided into 4 groups. MP119 was orally intubated for 7 days to group 1 and 3, and same volume of vehicle to group 2 and 4 as controls. After that, group 3 and 4 were intraperitoneally injected cadmium chloride at a single dose of 2 mg/kg. On the 8th experimental day, weights of testis, epididymis and seminal vesicle, number of sperm, concentrations of serum testosterone and cGMP were determined. The number of sperm, the concentrations of testosterone and cGMP were significantly increased in two experimental groups (group 1, 3). These results suggest that MP119 enhanced the sexual function of male mice, and could protect the sexual organs from the cadmium chloride as one of the endocrine disrupters.