• 생약학회지
• /
• 제34권1호통권132호
• /
• pp.109-117
• /
• 2003

Arachidonic acid(AA), which is stored in membrane glycerophospholipids, is liberated by phospholipase $A_2(PLA_2)$ enzymes and is sequentially converted to cyclooxygenase (COX) and lipoxygenase (LOX) then to various bioactive prostaglandins (PGs,) and leukotrienes (LTs). In order to find the specific inhibitors of AA metabolism enzymes such as $PLA_2$, COX-2, 5-LO and lyso PAF acetyltransferase. 195 Korean indigenous plant extracts were evaluated for their inhibitory activity on $PGD_2,\;LTC_4$ production from cytokine-induced mouse bone marrow-derived mast cells (BMMC) and arachidonic acid released from phospholipid and PAF production from lyso PAF. From this screening procedure, methanol extract of eight plants such as Saururus chinensis, Aster tataricus, Chrysanthemum cinerariaefolium, Reynoutria japonica, Disocorea nipponica, Epimedium koreanum, impatiens textori, Veronica rotunda var. subintegra were found to inhibit production of inflammatory mediators in vitro assay system.

• The Korean Journal of Physiology and Pharmacology
• /
• 제1권4호
• /
• pp.393-402
• /
• 1997

In the present study, we characterized the angiotensin II (AII)-induced relaxations in the phenylephrine-precontracted rabbit mesenteric arteries with endothelium. 1) AII-induced relaxation was consistently observed in the rabbit mesenteric arteries with and without endothelium, but not in the aortic segment with endothelium. 2) AII-induced endothelium-dependent relaxation was markedly inhibited by $N^w-nitro-L-arginine$ (L-NNA, $100\;{\mu}M$), methylene blue ($10\;{\mu}M$) and LY83583 ($10\;{\mu}M$), respectively. 3) Inhibition of cyclooxygenase with indomethacin ($10\;{\mu}M$) strongly decreased the vasorelaxant response to AII irrespective of the presence of endothelium. 4) 7-Ethoxyresorufin ($1\;{\mu}M$) and clotrimazole ($1\;{\mu}M$), inhibitors of cytochrome P-450-dependent arachidonic acid metabolism, greatly attenuated the vasodilator response to AII. 5) Carbacyclin, arachidonic acid and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) caused concentration-dependent relaxations in the mesenteric artery with endothelium, which were inhibited by L-NNA and methylene blue. 6) AII and $PGF_{2{\alpha}}$ significantly stimulated cyclic GMP formation in the mesenteric arteries with endothelium, which was inhibited by L-NNA and methylene blue, respectively. 7) AII enhanced synthesis of $PGF_{2{\alpha}}$ and 6-keto $PGF_{1{\alpha}}$ from the arterial segments with endothelium, which was inhibitable by indomethacin, but not by L-NNA. In conclusion, the vasorelaxant responses to AII of the rabbit mesenteric artery with endothelium are subserved by arachidonic acid and its metabolites produced via activation of cyclooxygenase and cytochrome P-450 enzyme as well as by nitric oxide.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 1995년도 Proceedings of special lectures on Molecular Biological Approaches to Plant Disease National Agricultural Science and Technology Institute Suwon, Korea
• /
• pp.55-75
• /
• 1995

Induction of HMG-Co A reductase (HMGR) is essential for the biosynthesis of sesquiterpenoid phytoalexins and steroid derivatives in Solanaceous plants following wounding and pathogen infection. To better understand this complex step in stress-responsive isoprenoid synthesis, three classes of cDNAs for HMGR (hmg1, hmg2, and hmg3) were isolated from a potato tuber library. The potato cDNAs had extensive homology in open reading frames but had low homology in the 3'-untranslated regions. RNA gel blot analysis using gene-specific probes revealed that hmg1 is induced by wounding but wound induction is strongly suppressed by arachidonic acid or by inoculation with Phytophthora infestants. In contrast, hmg2 and hmg3 are slightly induced by wounding and strongly enhanced by arachidonic acid or inoculation. The induction and suppression of HMGR genes parallel the suppression of steroid and stimulation of sesquiterpenoid accumulations observed in earlier investigations. Treatment of the tuber disks with a low concentration of methyl-jasmonate doubled the wound induced accumulation of hmg1 transcripts and steroid-glycoalkaloid accumulation, but did not affect the abundance of transcripts for hmg2 or hmg3 nor induce phytoalexins. High concentration of methyl-jasmonate suppressed hmg1 mRNA and steroid-glycoalkaloid accumulation, induced hmg3 mRNA, and did not elicit phytoalexins. Lipoxygenase inhibitors suppressed the accumulation of of hmg1 transcripts and steroid-glycoalkaloids, which were restored by exogeneous methyl-jasmonate. Methyl-jasmonate applied together with arachidonic acid enhanced the elicitor induced accumulation of sesquiterpenes and sustained steroid-glycoalkaloid levels with transcript levels for the various HMGR mRNAs equal to or greater than wound-only treatment. These results domonstrate that the consequences of wound- and pathogen-responses of plants are different at the levels of gene expression and associated secondary metabolism.

• 한국응용곤충학회지
• /
• 제61권1호
• /
• pp.173-195
• /
• 2022

척추동물과 유사하게 곤충도 인지질분해효소(phospholipase A₂)의 촉매 작용으로 다양한 아이코사노이드를 합성한다. 그러나 일련의 아이코사노이드 생합성과정은 척추동물과 차이를 보이는데, 이는 곤충의 인지질에는 전구물질인 아라키도닉산의 함량이 낮기 때문이다. 대신에 비교적 풍부하게 존재하는 다가불포화지방산인 리놀레익산을 기반으로 사슬 연장 및 불포화반응으로 아라키도닉산을 합성하여 척추동물과 같이 아이코사노이드 전구물질로 이용하는 것 같다. 이렇게 해서 형성된 아라키도닉산은 다시 척추동물의 cyclooxygenase와 유사한 peroxynectin이 PGH₂ 형태의 프로스타글란딘(prostaglandin: PG) 전구물질을 형성하게 된다. 이후 여러 이성체 효소들의 특이적 반응에 의해 PGA₂, PGD₂, PGE₂, PGI₂, TXB₂의 다양한 PG가 생성된다. 반면에 또 다른 형태의 아이코사노이드인 에폭시아이코사트리에노익산(epoxyeicosatrienoic acid: EET)은 척추동물과 유사한 단일산화효소의 산화반응으로 아라키도닉산을 전구물질로 5,6-EET, 8,9-EET, 11,12-EET, 14,15-EET를 형성하게 된다. 그러나 세 번째 아이코사노이드 부류인 류코트리엔(leukotriene)의 경우 곤충 체내 존재는 확인되었지만 생합성 과정은 아직 밝혀지지 않았다. 이들 아이코사노이드가 곤충의 대사, 배설, 면역 및 생식에 관여하는 생리작용을 중개한다. 따라서 아이코사노이드 생합성 과정을 교란하는 물질 탐색은 새로운 살충제 개발 전략이 된다. 본 종설은 이 가운데 PG의 곤충 면역 중개 기작을 소개한다.

• Natural Product Sciences
• /
• 제6권4호
• /
• pp.170-178
• /
• 2000

Flavonoids are natural polyphenolic compounds widely distributed in plant kingdom. Although many flavonoids were found to show anti-inflammatory activity in vitro and in vivo, the potency of anti-inflammatory activity was not enough for a clinical trial. Thus, a search for finding potential flavonoid molecules is continuing. In this review, in vivo anti-inflammatory activity of various flavonoid derivatives is summarized mainly based on the results obtained in authors' laboratories. Among them, several biflavonoids such as amentoflavone and ginkgetin were found to possess anti-inflammatory activity on animal models of acute/chronic inflammation comparable to nonsteroidal and steroidal anti-inflammatory drugs currently used. In respect of their action mechanisms, the effects on arachidonic acid metabolism and nitric oxide production were described. Some flavonoids directly inhibit cyclooxygenase and/or lipoxygenase. Biflavones such as ochnaflavone and ginkgetin are inhibitors of phospholipase $A_2$. In recent studies, certain flavonoids were also found to suppress cyclooxygenase-2 and inducible nitric oxide synthase expression induced by inflammatory stimuli. Therefore, it is suggested that anti-inflammatory activity of the certain flavonoids (mainly flavones, flavonols and biflavonoids) may be mediated by direct inhibition of arachidonic acid metabolizing enzymes as well as suppression of the enzyme expression involved in inflammatory responses.

• Journal of Nutrition and Health
• /
• 제37권3호
• /
• pp.182-192
• /
• 2004

Conjugated linoleic acid (CLA) is the mixture of positional and geometric isomers of linoleic acid (LA), which is found abundantly in dairy products and meats. This study was performed to investigate the anticarcinogenic effect of CLA in HepG2 hepatoma cells. HepG2 cell were treated with LA and CLA at the various concentrations of 10, 20, 40, 80 uM each at different incubation times. After each incubation times, cell proliferation, fatty acids incorporation into cell, peroxidation and postaglandin E$_2$ (PGE$_2$) and thromboxane $A_2$ (TXA$_2$) for the eicosanoid metabolism were measured. LA treated HepG2 cells were increased cell growth 6 - 70％ of control whereas CLA increased cell death the half of those in LA group (p 〈 0.001). LA and CLA were incorporated very well into the cellular membranes four times higher than in control according to concentration and longer incubation times. Moreover, LA synthesized significantly arachidonic acids corresponding with LA concentration compared to CLA supplementation. The supplementation with LA increased intracellular lipid peroxides concentration corresponding with LA concentration and five times higher than those in CLA significantly at any incubation times (p 〈 0.001). PGE$_2$ and TXA$_2$ levels were three to twenty times lower in condition of CLA treatments than LA, respectively. Overall, the dietary CLA might change the HepG2 cell growth by the changes of cell composition, production of lipid peroxide. Since CLA have not changed the levels of arachidonic acid of cell membrane, which was sources of eicosanoids, eicosanoid synthesis was not increased in CLA compared to LA. Our results was suggest CLA has a possibility to protect the progress of atherosclerosis because CLA does not produce lipid production and endothelial contraction factors in liver.

• Journal of Nutrition and Health
• /
• 제33권6호
• /
• pp.632-638
• /
• 2000

This study was designed to observe the effect of green tea on colon tumor incidence and biomarkers of colon carcinogenesis in 1, 2-dimethlhydrazine-treated rats. Male Sprague Dawley rats at 7 weeks of age were divided into two groups: control and green tea(GT) groups. Control rats had distilled water as drinking water but GT group received green tea extracts(2.5%, w/v water) as drinking water throughout the experiment periods. All rats were fed the experimental diet containing 15% fat by weight for 20 weeks. and were i.m. injected with DMH for 6 weeks to give total dose of 180mg/kg body weight. Tumor incidence was reduced in GT group (39%) compared with control group (56%) Green tea significantly reduced cell proliferation (total cells per crypt, crypt length and proliferative zone) in colonic mucosa and also significantly reduced the levels of preformed prostalandin E2(PGE2) and thromboxance B2(TXB2) in colonic mucosa but the fatty acid profile of total lipid in colonic mucosa was not significantly influenced by green tea. However the relative percent of C20:4 and the levels f preformed PGE2 and TXB2. were significantly higher in tumor tissue compared with normal surrounding mucosa.Green tea increased the fecal excretion of total bile acid but not scondary bile acid which is known as one of promoters for colon cancer,. These results suggest that green tea could have preventive effect against colon cancer when consumed daily by influencing on antioxidant effect and the metabolism of arachidonic acid.

• Tuberculosis and Respiratory Diseases
• /
• 제39권4호
• /
• pp.304-309
• /
• 1992

연구배경 : 폐포대식세포에서 아라카돈산 대사산물의 생성을 자극하는 일부 인자에 의해서 지속적인 자극시 이와같은 자극으로 인해 생산된 아라키돈산 대사산물이 만성적인 기관지 수축과 섬유화, 계속되는 독성 산소기의 분비를 통하여 잘환의 진행을 항진시키게 된다고 알려져 있고 또한 폐가 외부 물질에 만성적으로 폭로됨으로 인한 질환은 진폐증이 그 대표적인 예라고 할 수 있다. 그러으로 대식세포나 호중구 또는 섬유모세포에서 생산하는 prostaglandin이나 leukotriene등 대사산물의 측정을 통하여 진폐증의 질환의 진행정도를 파악하려는 노력이 계속되고 있으나 아직 명백한 결론을 얻지 못하고 있다. 본 연구는 시험관내에서 폐포대식세포를 유리규산으로 자극시 아라키돈산 대사산물의 측정을 통하여 섬유화 과정에 미치는 prostaglandin $E_2$와 leukotriene $B_4$의 영향을 연구하기 위하여 시행되었다. 방법 : 쥐의 폐포대식세포를 유리규산분진, 자연산 석탄 분진, Lipopolysaccharide, calcium ionophore과 같은 자극제와 같이 배양하고 24, 48시 간후 방사선 동위원소를 이용하여 $PGE_2$와 $LTB_4$를 측정하였다. 결과 : 1) 정상 흰쥐의 폐포대식세포에서 $PGE_2$는 유리규산 자극시 48시간에서 무자극군에 비하여 유의한 감소를 보였다. 2) 실험규폐증군의 폐포대식세포에서 유리된 $PGE_2$는 유리규산 및 자연산 석탄분진으로 자극시 48시간에서 무자극군에 비하여 유의하게 감소하였다. 3) 정상 흰쥐의 폐포대식세포에서 $LTB_4$는 유리규산 자극후 24시간 및 48시간, 그리고 자연산 석탄분진으로 자극시 48시간에서 무자극군에 비하여 유의한 증가를 보였다. 4) 실험 규폐증의 폐포대식세포에서 유리된 $LTB_4$는 유리규산 및 자연산 석탄분진 자극시 장시간 및 48시간에서 무자극군에 비하여 모두 유의하게 증가하였다. 결론 : 본 실험 결과 시험관에서 유리규산과 자연산 석탄분진에 폐포대식세포가 폭로시 폐에 염증반응을 항진시킬 수 있는 방향으로 아라키돈산 대사가 이루어짐을 알았고 이와갈은 아라키돈산 대사의 변화가 진폐증의 병태생리에 중요한 인자로서 작용할 가능성이 있다고 하겠다.

• 한국식생활문화학회지
• /
• 제35권3호
• /
• pp.302-310
• /
• 2020

Although the age-standardized incidence of gastric cancer has decreased in Korea, it remains the second most common type of cancer. The purpose of this study was to analyze the phospholipid fatty acid compositions of gastric mucosa in gastric cancer. Cancerous mucosa and noncancerous mucosa adjacent to cancerous tissues were obtained from 29 patients who had undergone gastrectomy for gastric adenocarcinoma. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS) were separated from phospholipids by thin-layer chromatography, and fatty acids were analyzed by gas chromatography. In cancerous mucosa, saturated fatty acids of total phospholipids and stearic acid of PE and PC contents as well as total phospholipids were significantly more abundant than in noncancerous tissues. The ratios of ω6 fatty acid products to linoleic acid of PC, PE, PI, and PS contents as well as total phospholipids were significantly higher in cancerous mucosa than in noncancerous mucosa. Arachidonic acid levels of PE and PI were significantly higher, but the PC level was lower in cancerous mucosa. These results suggest that the characteristic differences in fatty acid compositions of phospholipids and their subfractions shown in gastric cancerous mucosa may be affected by changes in lipid metabolism in gastric carcinogenesis. Further studies on structural and functional changes in phospholipids related to gastric carcinogenesis will be needed.

• 동아시아식생활학회지
• /
• 제24권3호
• /
• pp.325-334
• /
• 2014

The effects of aloe on liver function and lipid metabolic disorders induced by alcohol consumption were studied in rats using aloe power (0.25%, 0.5%, 1%) and 10% ethanol. 35 Sprague-Dawley (male, 4 weeks old) rats were divided into five groups and fed experimental diets for six weeks. Body weights of rats tended to be lower in all alcohol supplemented groups than in the control. Food intakes and dry feces per day were significantly lower in all alcohol supplemented groups than in the control. Atherogenic indices (AI) were highest in the alcohol group and decreased in proportion with aloe amount. Serum triglyceride level was significantly higher in the alcohol group than in the control, but tended to be lower in the aloe supplemented groups. In relation to liver function, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), and alkaline phosphatase (ALP) activities tended to be higher in the alcohol groups than in the control, but lower in the aloe groups, especially in the alcohol+0.5% AO group. The levels of liver cholesterol were significantly lower in the alcohol group than in the control and aloe supplemented groups. In the histochemical evaluation, fat droplets appeared extensively on the liver-lobule in the alcohol group, whereas they decreased slightly in the alcohol+0.25% AO group and apparently disappeared in the alcohol +0.5% AO. On the other hand, fat droplets appeared again on the liver-lobule in the alcohol+1% AO group, but were reduced compared with the alcohol group. Regarding the fatty acid composition of adipose tissue triglycerides, the level of linoleic acid (18:2) was significantly higher in the aloe supplemented group. Regarding the fatty acid composition of liver phosphatidylcholine (PC), the level of linoleic acid was higher in the alcohol group and alcohol+1% AO group than the other groups. In contrast, the level of arachidonic acid was significantly lower in the alcohol group. As a result, arachidonic / linoleic acid ratios were significantly lower in the alcohol group compared to the control group, whereas the ratios of the aloe supplemented groups were similar to that of the control group. Therefore, aloe had some beneficial effects on lipid metabolic disorders induced by alcohol and affected desaturation of fatty acids.