• Korean Journal of Pharmacognosy
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• v.24 no.4
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• pp.304-308
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• 1993

A platelet activating factor(PAF) antagonist ginkgolides produced from Ginkgo biloba are well known for their potential usage in septic shock and other PAF related diseases. Even though they are extracted from the leaves and on occasion the root bark, the exact biosynthetic site and pathway have not proved yet. In order to locate the enzymes involved and elucidate the biosynthetic site of the compounds, embryo-derived aseptic intact plantlet and plantlet without root have been cultured on 0.3% active carbon-containing solid Murashige and Skoog's medium. The leaves from the six-week-old normal plantlet contained similar amount of ginkgolide B to that of outdoor plant leaves, while the plantlets without root had less than 30% of the ginkgolide B compared to the in vitro intact plantlets. The results suggest that the ginkgolides may be synthesized in the root and transported to the aerial part.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1391-1398
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• 2005

The anti-thrombic properties of the oriental herbal medicine Daejowhan(DJW, 大造丸) which consists of 11 kinds of herbs (indicated as ratio) of Rehmanniae Radix 24%, Hominis Placenta 5%, Testudinis Carapax 9%, Eucommiae Cortex 9%, Asparagi Radix 9%, Phellodendri Cortex 9%, Achyranthis Radix 7%, Liriopis Tuber 7%, Angelicae Sinensis Radix 7%, Ginseng Radix 5% and Schizandrae Fructus 3% were investigated. The water extracts from DJW inhibited Platelet-activating factor(PAF) induced platelet aggregation. DJW was extracted with methanol and further fractionated by ethylacetate. A 70% methanol extract showed a strong inhibition against PAF-induced aggregation in vitro and in vivo assays. The ethylacetate soluble fraction was shown to have inhibitory effect on PAF-induced platelet aggregation in vitro assay. The ethylacetate soluble fraction specially protected against the lethality of PAF, while verapamil did not afford any protection. These results indicate that the water extracts and alcoholic-fractions inhibit the action of PAF in vivo by an antagonistic effect on PAF, so that it may be useful in treating disorders caused by PAF, such as acute allergy, inflammation, asthma, gastrointestinal ulceration, toxic shock and so forth. DJW was investigated regarding its assumed anti-thrombic action on human platelets which was deduced from its ability to suppress Arachidonic acid(AA)-induced aggregation, exocytosis of ATP, and inhibition of Cyclooxygenase(COX) and Thromboxane synthase(TXS) activity. The latter two effects were estimated from the generation of Prostaglandin $E_2(PGE_2)$ and Thromboxane $A_2(TXA_2)$ respectively. Exogenously applied AA ($100{\mu}mol/{\ell}$) provoked a $89\%$ aggregation of platelets, the release of 14 pmol ATP, and the formation of either 225 pg $TXA_2$ or 45 pg $PGE_2$, each parameter being related to 106 platelets. An application of DJW 5 min before AA dose-dependently diminished aggregation, ATP-release and the synthesis of $TXA_2$ and $PGE_2$ with $IC_{50}$ values of 74, 108, 65, $72{\mu}g/m{\ell}$, respectively. The similarity of the $IC_{50}$ values suggest an inhibition of COX by DJW as primary target, thus suppressing the generation of $TXA_2$ which induces aggregation of platelets and exocytosis of ATP by its binding on $TXA_2$-receptors.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.261.1-261
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• 1996

No Abstract, See Full Text

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.203-203
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• 1996

It has been known that pinusolide isolated from Biota orientalis inhibits specifically [$^3$H] PAF binding to and PAF-induced aggregation of rabbit platelets in vitro. The present study was undertaken to evaluate the effects of pinusolide on hypotension and bronchoconstriction due to PAF. PAF(i.v.) in doses of 0.01 to 0.3 $\mu\textrm{g}$/kg induced a dose-dependent hypotension without tachyphylaxis in rat. Pinusolide(5～20 mg/kg, i.v.) inhibited PAF(0.03 $\mu\textrm{g}$/kg, i.v.)-induced hypotension dose-dependently, while it failed to block the hypotensive action of histamine, serotonin and acetylcholine. It inhibited bronchoconstriction and cutaneous vascular permeability induced by PAF in anesthetized guinea-pigs and rats, respectively, but it showed no inhibitory effect on the increase in bronchial resistance by histamine and acetylcholine. These results strongly suggest that in vivo pinusolide acts as a selective antagonist of PAF.

• Reproductive and Developmental Biology
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• v.30 no.2
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• pp.75-79
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• 2006

The developmental regulation of the preimplantation mammalian embryos is a fundamental step for preparing the implantation and it may be regulated by several autocrine and paracrine factors including platelet-activating factor. PAF improved the embryonic survival and implantation but its role during blastocyst development is still largely unknown. In this study, the effects and the possible pathway of PAF on developmental regulation of blastocyst to hatching stage were investigated. Developmental pattern in hatching embryo was a concentration-response curve showing maximal activity at 1 nM PAF, with decreasing activity at higher concentrations. $50{\mu}M$ 1-(5-isoquinolimnesulfonyl)-2-methylpiperazinme dihydrochloride (H-7), a PKC inhibitor, inhibited the progression of blastocyst to hatching embryo. In addition H-7 blocked the PAF effects on the blastocyst development. Besides tetradecanoylphorbol acetate (TPA), a PKC activator stimulated development of blastocyst to the hatching stage. These finding revealed that PAF support the blastocyst development to the hatching embryo. Also it is suggested that PAF action pathways in hatching supporting include the PKC signaling pathway.

• Biomolecules & Therapeutics
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• v.7 no.3
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• pp.234-241
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• 1999

The present study assessed the cerebroprotective effect of platelet-activating factor(PAF) antagonists in transient cerebral ischemia of rats. Right middle cerebral artery (MCA) of Sprague-Dawley rats was occluded for 2 hours using an intraluminal filament technique, and was reperfused for 6 hours following cerebral ischemia. The infarct area of seven coronal brain slices was measured morphometrically following stain ing in the 2% 2,3,5-triphenyltetrazolium chloride solution. The changes in regional cerebral blood flow (rCBF) and pial arteriolar diameter were measured by laser-Doppler flowmetry and by a videomicroscopy, respectively. The infarct size was significantly reduced by PAF antagonists, BN 52021 and CV-6209, which were administered i.p. 10 min before MCA occlusion. Pretreatment with PAF antagonists significantly restored the changes in pial arterial diameter as well as those in rCBF during the period of cerebral ischemia-reperfusion. PAF antagonists significantly inhibited the inducible nitric oxide synthase activity in the pial arteries ipsilateral to ischemia. These results suggest that PAF antagonists exert a cerebroprotective effect against ischemic brain damage through an improvement of postocclusive cerebral blood flow.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1051-1058
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• 2014

Platelet-activating factor receptor (PAFR) plays an important role in bacterial infection and inflammation. We examined the effect of the bacterial cell wall components lipopolysaccharide (LPS) and lipoteichoic acid (LTA) from Lactobacillus plantarum (pLTA) and Staphylococcus aureus (aLTA) on PAFR expression in THP-1, a monocyte-like cell line. LPS and aLTA, but not pLTA, significantly increased PAFR expression, whereas priming with pLTA inhibited LPS-mediated or aLTA-mediated PAFR expression. Expression of Toll-like receptor (TLR) 2 and 4, and CD14 increased with LPS and aLTA treatments, but was inhibited by pLTA pretreatment. Neutralizing antibodies against TLR2, TLR4, and CD14 showed that these receptors were important in LPS-mediated or aLTA-mediated PAFR expression. PAFR expression is mainly regulated by the nuclear factor kappa B signaling pathway. Blocking PAF binding to PAFR using a PAFR inhibitor indicated that LPS-mediated or aLTA-mediated PAF expression affected TNF-${\alpha}$ production. In the mouse small intestine, pLTA inhibited PAFR, TLR2, and TLR4 expression that was induced by heat-labile toxin. Our data suggested that pLTA has an anti-inflammatory effect by inhibiting the expression of PAFR that was induced by pathogenic ligands.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.107-120
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• 1993

Particulate or soluble stimuli appear to stimulate phagocytic cell's response by the change of $Ca^{2+}$ mobilization and by the activation of protein kinase C. In contrast, it is reported that activation of protein kinase C could attenuate agonist-stimulated elevation of $Ca^{2+}i$ in neutrophils. PAF elicited an increase of $Ca^{2+}i$ in peritoneal macrophages in a dose dependent fashion and $Ca^{2+}$ extrusion was accompanied. PAF-induced elevation of $Ca^{2+}i$ was not affected by TMB-8, verapamil and TTX. TEA stimulated PAF-induced mobilization of $Ca^{2+}i$ and delayed lowering of $Ca^{2+}i$. Five mM EGTA almost completely inhibited PAF-induced mobilization of $Ca^{2+}i$. After the addition of PAF, membrane permeability was markedly increased up to 5 min and then slowly increased. PAF-induced LDH release was slightly decreased by EGTA plus TMB-8. PAF-stimulated superoxide generation was inhibited by EGTA, TMB-8 and verapamil but not affected by TTX and TEA. PAF-induced elevation of $Ca^{2+}i$, increased membrane permeability and superoxide generation were inhibited by IQSP, chlorpromazine and propranolol. PAF-induced LDH release was significantly inhibited by chlorpromazine and minimally decreased by propranolol. After the pretreatment with PMA, the stimulatory effect of PAF on the elevation of $Ca^{2+}i$ and LDH release in macrophages was significantly decreased. These results suggest that PAF may exert the stimulatory action on peritoneal macrophages of mouse by the elevation of $Ca^{2+}i$ and by the activation of protein kinase C. Preactivation of protein kinase C appears to attenuate the stimulatory action of PAF on macrophage response.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.2
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• pp.99-104
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• 2000

We investigated the action of NOS inhibitors on NOS in rats. Both of nitric oxide synthase inhibitors, $N^G$-monomethyl-L-arginine $(L-NMMA,\;3\;{\mu}M)$ or $N^G$-nitro-L-arginine methylester $(L-NAME,\;30\;{\mu}M),$ augmented phenylephrine $(PE,\;10^{-7}\;M)-induced$ contraction which was inhibited by acetylcholine (ACh) in rat thoracic aorta. This augmentation by L-NAME or L-NMMA was attenuated with the treatment of NO precursor, arginine. ACh, however, decreased the augmentation induced by L-NMMA, but not by L-NAME. Superoxide dismutase (SOD, 50 u/ml) potentiated an inhibitory effect of ACh on the PE $(10^{-7}\;M)-induced$ contraction. It has been known that platelet activating factor itself induces iNOS. Platelet activating factor $(PAF,\;10^{-7}\;M)$ inhibited PE $(10^{-7}\;M)-induced$ contraction. Pretreatment with L-NMMA (30 mM) or L-NAME (30 mM) significantly blocked the inhibitory action of PAF on PE-induced contraction. L-NMMA (100 mM) or L-NAME (100 mM) reduced nerve conduction velocity (NCV) relevant to nNOS in rat sciatic nerve. ACh attenuated the reduction of NCV by L-NMMA-, but not by L-NAME-induced reduction of NCV. These results suggest that L-NMMA and/or L-NAME have different action on three types of NOS in rats.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.1
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• pp.1-6
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• 1996

There are a number of problems during the process of culture in vitro on fertilization and embryo development compared to those on in vivo counterparts. And the platelet activating factor (PAF), which is found not only in mammalian spermatozoa but also preembryos, is implicated on reproductive process. To improve the environment of culture on in vitro fertilization and embryo development, coculture using salpingeal epithelial cells has been considered to accept the better result on pregnancy rate. This study was designed to determine if two different culture systems, coculture alone and PAF treated coculture, are positive or negative influence on process of in vitro fertilization and embryo culture in mouse. The cell cleavage rate reached to 2-4 cell stage at 24 hours of culture is 56.81% (50/88) and 48.21%(54/112) respectively, in PAF treated group which is added PAF on coculture and in coculture group. But the rate of cells cleavage was similar in both group after 48 hours of culture. The rate of unfertilization after insemination of oocytes was higher in coculture group(55..53%) than in PAF treated group(42.37%). And in assessment of undeveped embryos, the rate of equalized cell block was similar on both, coculture alone (35.3%)and PAF treated coculture(35.5%). while unequalized cell block was higher rate in PAF treated coculture(19.4%) than coculture alone (11.8%). But the rate of cytoplasmic degeneration of undeveloped embryos was significantly higher in PAF treated coculture than coculture alone. In conclusion, we have observed that PAF treated coculture is superior in the rates of in vitro fertilization and early embryo cell cleavage compared to those in coculture alone, but there is no difference on the rates of embryo develpments, cell degeneration, cell quality in both PAF treated coculture and coculture alone when the embryo cells were continuosly cultured for 48 hours or more.