• Title, Summary, Keyword: Phospholipase $A_2$

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Anti-inflammatory Activity and Phospholipase $A_2$ Inhibition of Noni (Morinda citrifolia) Methanol Extracts (노니(Morinda citrifolia) 메타놀 추출물의 Phospholipase $A_2$ 억제와 항염증 활성)

  • Choi, Byung Chul;Sim, Sang Soo
    • YAKHAK HOEJI
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    • v.49 no.5
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    • pp.405-409
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    • 2005
  • To investigate anti-inflammatory activity of Noni extracts, we measured the phospholipase $A_2$ activity using both in vitro and in vivo system. Water soluble fraction of Noni extracts did not affect melittin-induced arachidonic acid release, whereas lipid soluble fraction inhibited it in a dose dependent manner in Raw 264.7 cells. The purified phos­pholipase $A_2$ activity was dose-dependently inhibited by lipid soluble fraction of Noni extracts but not by its water soluble fraction. Lipid peroxidation, myeloperoxidase and phospholipase $A_2$ activity in incised skin of mice were significantly increased as compared with those in non-incised skin, and these increase was attenuated by the treatment with Noni pow­der. Our data suggest that Noni extracts has anti-inflammatory activity, and this is, in part, caused by inhibitory activity of phospholipase $A_2$.

Bioluminescent assay of Phospholipase C Using A Luminescent Marine Mutant Bacterium Vibrio harveyi M-17

  • Cho, Ki-Woong;Mo, Sang-Jun;Lee, Hyi-Seung;Park, Jung-Rae;Jongheon Shin
    • Journal of Microbiology
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    • v.38 no.3
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    • pp.150-155
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    • 2000
  • A bioluminescent assay method for detecting the activity of phospholipase C(PLC; phosphatidyl choline cholinephosphohydrolase, EC 3.1.4.3) was developed using bioluminescent marine bacteria. Phospholipase C from Bacillus cereus and sn-1,2- dimyristoyl glycerol was further hydrolyzed with lipase from Candida ecylidracea. The hydrolyzed myristic acid was quantified using a dark mutant of Vibrio harveyi (designated as M-17). The in vivo light intensity of which was stimulated specifically up to one thousand fold in the presence of myristic acid. The rates of the hdrolysis of the DMPC substrate by the phospholipase measured by the luminescence method were linear with time and the were estalished to detect as little as 0.1 mUnit of phospholipase C and 5 nM of myristic acid production.

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The Study of Aati-cancer Effects of Bee Venom for Aqua-acupuncure (약침용(藥鍼用) 봉독성분(蜂毒成分) 중(中) Apamin, Melittin의 항암작용(抗癌作用))

  • Kwon, Do-Hee;Lee, Jae-dong;Choi, Do-Yong
    • Journal of Acupuncture Research
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    • v.18 no.1
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    • pp.129-145
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    • 2001
  • Objectives : To characterize the antitumorigenic potential of three representative bee venom components, Melittin, Apamin, and Phospholipase A2, their effects on cell proliferation and apotosis of the human melanoma cell line SK-MEL-2 were analyzed using molecular biological approaches. Methodes & Results : To determine the doses of the drugs that do not induce cytotoxic damage to this cell line, cell viability was examined by MTT assay. While SK-MEL-2 cells treated with 0.5 - 2.0㎍/㎖ of each drug showed no recognizable cytotoxic effect, marked reductions of cell viability were detected at concentrations over 5.0㎍/㎖. [3H]thymidine incorporation assay for cell proliferation demonstrated that DNA replication of SK-MEL-2 cells is inhibited by Apamin and Phospholipase A2 in a dose-dependent manner. Consistent with this result, the cells were accumulated at the G1 phase of the cell cycle after treatment with Apamin and Phospholipase A2, whereas no detectable change in cell proliferation was identified by Melittin treatment. In addition, tryphan blue exclusion and flow cytometric analyses showed that all of these drugs can trigger apoptotic cell death of SK-MEL-2, suggesting that Melittin, Apamin, and Phospholipase A2 have antitumorigenic potential through the suppression of cell growth and/or induction of apoptosis. Qantitative RT-PCR analysis revealed that Apamin and Phospholipase A2 inhibit expression of growth-promoting genes such as c-Jun, c-Fos, and Cyciin D1. Furthermore, Phospholipase A2 induced tumor suppressors p53 and p21/Wafl. In addition, all three drugs were found to activate expression of a representative apoptosis-inducing gene Bax while expression of apoptosis-suppressing Bcl-2 and Bcl-XL genes was not changed. Taken together, this study strongly suggests that Metittin, Apamin, and Phosphalipase A2 may have antitumorigenic activities, which are associated with its growth-inhibiting and/or apoptosis-inducing potentials.

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Bradykinin-Mediated Stimulation of Phospholipase D in Rabbit Kidney Proximal Tubule Cells

  • Park, Kyung-Hyup;Jung, Jee-Chang;Chung, Sung-Hyun
    • Biomolecules & Therapeutics
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    • v.2 no.1
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    • pp.39-46
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    • 1994
  • The present study was undertaken to demonstrate whether or not bradykinin activates a phospholipase D in rabbit kidney proximal tubule cells. By measuring the formation of [$^3$H]phosphatidic acid and [$^3$H]phosphatidylethanol we could elucidate the direct stimulation of phospholipase D by bradykinin. Bradykinin leads to a rapid increase in [$^3$H]phosphatidic acid and [$^3$H]diacylglycerol, and [$^3$H]phosphatidic acid formation preceded the formation of [$^3$H]diacylglycerol. This result suggests that some phosphatidic acid seems to be formed directly from phosphatidylcholine by the action of phospholipase D, not from diacylglycerol by the action of diacylglycerol kinase. In addition, the other mechanisms by which phospholipase D is activated was examined. We have found that phospholipase D was activated and regulated by extracellular calcium ion and pertussis toxin-insensitive G protein, respectively. It has also been shown that bradykinin may activate phospholipase D through protein kinase C-dependent pathway. In conclusion, we are now, for the first time, strongly suggesting that bradykinin-induced activation of phospholipase D in the rabbit kidney proximal tubule cells is mediated by a pertussis toxin-insensitive G protein and is dependent of protein kinase C.

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Purification of Phospholipase $A_2$ from Scutellaria baicalensis Suspension Cells (황금 배양 세포로부터 Phospholipase $A_2$의 분리)

  • Ma, Choong-Je;Kim, Dae-Kyung
    • Korean Journal of Pharmacognosy
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    • v.40 no.1
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    • pp.13-17
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    • 2009
  • It was previously reported that yeast elicitor transiently increased oleanolic acid and ursolic acid in Scutellaria baicalensis suspension cultures and also doubled phospholipase $A_2$ ($PLA_2$) activity. Thus, $PLA_2$ was purified from the soluble fractions of S. baicalensis suspension cultures and the characters of the purified $PLA_2$ were identified. The $PLA_2$ was purified about 160 times compared with the starting soluble-protein extract from S. baicalensis suspension culture cells. The purified protein showed a molecular mass of about 43 kDa by SDS-PAGE. The purified plant $PLA_2$ had a neutral pH optimum (pH 7.0) and required $Ca^{2+}$ for activity. The $PLA_2$ activity was inhibited by mammalian $PLA_2$ inhibitors such as 5,8,11,14-eicosatetraynoic acid(ETYA) and arachidonyl trifluoromethyl ketone ($AACOCF_3$).

Inhibitory Effects of Hydroxybrazilin on the Platelet Phospholipase $A_2$ Activities in Normal and Streptozotocin Induced Diabetic Rats (Streptozotocin 유도 당뇨병 랫드의 혈소판 Phospholipase $A_2$ 활성에 미치는 Hydroxybrazilin의 영향)

  • Moon, Chang-Hyun;Lim, Dong-Soon;Cho, Tae-Soon;Kim, Ji-Young
    • YAKHAK HOEJI
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    • v.38 no.1
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    • pp.97-101
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    • 1994
  • Platelets play a very important role in nomal hemostasis and their functions are more enhanced in various pathogenic states than in normal state. Especially it has been postulated that abnormal platelet and endothelium function might be major factors of microcirculatory disturbance in diabetes mellitus. Hydroxybrazilin, a phenolic constituent of Hematoxylon campechianum has been examined for its inhibitory effect on platelet aggregation. Its antiaggregatory effect might be mediated through the decrease of ATP release from dense granule and those of thromboxane $A_2$ production in normal and streptozotocin induced diabetic rats. The present study was undertaken to gain insight into the mechanism that hydroxybrazilin inhibited thromboxane $A_2$ production in platelets. Thus we measured the effect of hydroxybrazilin on phospholipase $A_2$, a rate limiting step of thromboxane $A_2$ production, in normal and streptozotocin induced diabetic rats. Hydroxybrazilin significantly inhibited the platelet phospholipase $A_2$ activity in normal and streptozotocin induced diabetic rats.

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Effect of Phospholipase D on the L-$\alpha$-Dimyristoyl-phosphatidyl Choline Liposome Containing Cholesterol, L-$\alpha$-Phosphatidylinositol and L-$\alpha$-Phosphatidylserine (Cholesterol, L-$\alpha$-Phosphatidylinositol, L-$\alpha$-Phosphatidylserine을 함유한 L-$\alpha$-Dimyristoyl-phosphatidyl Choline 리포솜에 대한 Phospholipase D의 작용에 관한 연구)

  • 이은옥
    • YAKHAK HOEJI
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    • v.27 no.4
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    • pp.249-256
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    • 1983
  • When the reaction rate constant k of phospholipase D on liposome was measured by the ANS fluorometry, k of phospholipase D on DMPC liposome which was made of L-$\alpha$-PI, cholesterol and L-$\alpha$-PS decreased than that of phospholipase D on DMPC liposome with cholesterol or with PI and cholesterol. Optimal $Ca^{2+}$ concentration, the most important factor on effect of phospholipase D, also decreased to 1mM, as compared with 10mM and 60mM respectively when cholesterol and PI were added, and cholesterol only was added. The change of cholesterol Mol% had a great influence on k value of phospholipase D. But in case of addition of L-$\alpha$-PS to cholesterol, the influence was relatively diminished.

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Inhibitory Activity of Amentoflavone on Arachidonic Acid Releasing Enzyme, Phopholipase $A_2$ and Inhibition of Histamine Release from Mast Cells (Amentoflavone의 아라키돈산 유리효소인 phopholipase $A_2$에 대한 저해활성 및 비만세포에서 histamine 유리 억제효과)

  • Moon, Tae-Chul;Lee, Eun-Kyung;Lee, Sung-Ho;Son, Kun-Ho;Kim, Hyun-Pyo;Kang, Sam-Sik;Chang, Hyeun-Wook
    • Korean Journal of Pharmacognosy
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    • v.33 no.1
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    • pp.49-52
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    • 2002
  • Amentoflavone, naturally occurring biflavonoid, isolated from the leaves of Ginko biloba, selectively inhibited human seceretory phospholipase $A_2$. This compound potently and irreversibly inhibited human group IIA in a dose dependent manner with an $IC_50$ about $3\;{\mu}M$. Amentoflavone inhibited phospholipase $A_2$ by a noncompetitive manner with the apparent Ki value of $1{\times}10^{-5}M$. In addition, the inhibitory activity of amentoflavone is rather specific against group IIA phospholipase $A_2$ than group IB phospholipase $A_2$. Furthermore, this compound strong inhibit histamine release from $A_{23187}$ treated rat peritoneal mast cells. These results indicate naturally occurring biflavonoid represents a novel anti-inflammatory agent.

Phospholipase $A_{2}$ Activity and Lipid Peroxidation in Liver Microsome of Streptozotocin Induced Diabetic Rats (당뇨쥐의 간 Microsome에서 Phopholipase A_{2} 활성과 지질과산화)

  • 이순재;최정화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.5
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    • pp.908-913
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    • 1997
  • The purpose of this study was to investigate phospholipase $A_{2}$ activity and lipid peroxidation I streptozotocin induced diabetic rats. Sprague-Dawley male rats weighting-Dawley male rats weighting 300$\pm$10gm were randomly assigned to normal and STZ-induced diabetic group. Diabetes was induced by intravenous injection of 55mg/kg of STZ in sodium citrate buffer(pH 4.3). Animals were sacrificed at the 6th day of diabetic states. Body weight gains were lower in DM group. Phosphatidylcholine hydrolysis in liver was not significantly different between two groups, whereas phosphatidylethanolamine hydrolysis in liver was increased by 69% in DM group comparing with that of normal group. Liver microsomal phospholipase $A_{2}$ activity and level of TBARS was increased by 91%, 109% in DM group compared with that of normal group, respectively. The present results indicate that phospholipase $A_{2}$ activity is specific to PE hydrolysis, leading to lipid peroxidation process in STZ induced diabetic rats.

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Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells

  • Song, Ho-Sun;Kim, Hee-Rae;Ko, Myoung-Soo;Jeong, Jae-Min;Kim, Yong-Ho;Kim, Myung-Cheul;Hwang, Yeon-Hee;Sohn, Uy-Dong;Gimm, Yoon-Myoung;Myung, Sung-Ho;Sim, Sang-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.427-433
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    • 2010
  • This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase $A_2$ ($PLA_2$), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and $0.5\;{\mu}M$ melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free $PLA_2$ assay, we failed to observe tbe change of $cPLA_2$ and $sPLA_2$ activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells.