• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 국제심포지움
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• pp.88.2-98
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• 2002

A wide arry of naturally occurring substances particularly those present in dietary and medicinal plants, have been reported to possess substantial cancer chemopreventive properties. Certain phytochemicals retain strong antioxidative and anti-inflammatory properties which appear to contribute to their chemopreventive or chemoprotective activities. Inducible cyclooxygenase(COX-2) and nitric oxide synthase (iNOS) are important enzymes that mediate inflammatory processes. There is some evidence that expression of both COX-2 and iNOS is co-regulated by the eukaryotic transcription factor NF-$textsc{k}$B. Increased expression of COX-2 and/or iNOS has been associated with pathophysiology of certain types of human cancers as well as inflammatory diseases. Since inflammation is closely linked to tumor promotion, substances with potent anti-inflammatory activies are anticipated to exert chemopreventive effects on carcinogenesis, particularly in the promotion stage. An example is curcumin, a yellow pigment of turmeric (Curcuma longa L., Zingiberaceae), that strongly occurring diaryl heptanoids structurally related to curcumin have substantial anti-tumor promotional activities in two-stage mouse skin carcinogenesis. Thus, yakuchinone A [1-(4'-hydroxy-3'-methoxyphenyl)-7-phenyl-3heptanone] and yakuchinone B [1-(4'-hydroxy-3'methoxyphenyl)-7-phenylhept-1-en-3-one] present in Alpinia oxyphylla Miquel (Zingiberacease) attenuate phorbol ester-induced inflammation and papilloma formation in female ICR mice. These diarylheptanoids also suppressed phorbol ester-induced activation of epdermal ornithine decarboxylase and its mRNA expression when applied onto shaven backs of mice. Yakuchinone A and B as well as curcumin inhibited phorbol ester-induced expression of COX-2 and iNOS and their mRNA in mouse skin via inactivation of NF-$textsc{k}$B. Capsaicin, a major pungent ingredient of red pepper also attenuated phorbol ester-induced NF-$textsc{k}$B activation. Similar suppression of COX-2 and iNOS and down-regulation of NF-$textsc{k}$B activation for its DNA binding were observed with the ginsenosied Rg3 and the ethanol extract of Artemisia asiatica. We have also found that certain anti-inflammatory phytochemicals exert inhibitory effects on phorbol ester-induced COX-2 expression and NF-$textsc{k}$B activation in immortalized human breast epithelial (MCF-10A) cells in culture. One of the plausible mechanisms undelying inhibition by aforementioned phytochemicals of phorbol ester-induced NF-$textsc{k}$B activation involves interference with degragation of the inhibitory unit, I$textsc{k}$Ba, which blocks subsequent nuclear translocation of the functionally active p65 subunit of NF-$textsc{k}$B. the activation of epidermal NF-$textsc{k}$B by phorbol ester and subsequent induction of COX-2 hence appear to play an important role in intracellular signaling pathwasy leading to tumor promotion and targeted inhibition of NF-$textsc{k}$B may provide a new promising cancer chemopreventive strategy.

• 생명과학회지
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• 제25권9호
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• pp.976-983
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• 2015

Achyranthoside C dimethyl ester (ACDE)는 우슬에서 분리한 oleanolic acid glycoside이다. 본 연구에서는 RAW264.7 대식세포에서 ACDE의 항염증 효과를 관찰하고 그 작용 기전을 연구하였다. ACDE는 세포에 독성을 유도하지 않으면서 heme oxygenase-1 (HO-1)의 발현을 유도하였다. ACDE 는 HO-1의 발현에 관여하는 전사인자인 nuclear factor E2-related factor 2 (Nrf2)를 핵으로 이동시켰다. 또한 ACDE에 의한 HO-1의 발현은 phosphatidylinositol 3-kinase (PI-3K) 및 mitogen activated protein kinases (MAPK) 억제제에 의해 감소되었으며, ACDE가 Akt, c-Jun kinase (JNK), extracellular signal regulated kinase (ERK), p38 kinase의 인산화를 유도하였다. 한편 ACDE는 lipopolysaccharide (LPS)로 인한 nitric oxide (NO)의 생성과 inducible NO synthase (iNOS) 발현을 억제하였으며 HO-1 siRNA를 처리했을 때 ACDE가 iNOS의 발현을 억제하지 못하였다. 이상의 결과를 종합해보면, ACDE는 대식세포에서 PI3K/Akt 및 MAPK와 Nrf2 신호전달과정을 통해 HO-1의 발현을 유도함으로써 NO와 같은 염증매개물질의 생성을 억제한다는 것을 알 수 있다. 이러한 연구결과는 ACDE가 항염증제로 사용될 수 있음을 시사한다.

• Journal of Yeungnam Medical Science
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• 제14권2호
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• pp.337-349
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• 1997

세균 내독소에 의하여 발생하는 패혈성 쇼크와 혈관 반응성 감소의 원인을 관찰하였다. 혈관 절편이 고정된 실험조에 세균 내독소 0.2 mg 투여한 경우 $36{\pm}3.65$ nM NO가 발생되었고, NO 발생에 의한 혈관 이완 효과를 억제하기 위해 전처치한 L-MAME, methylene blue는 혈관 절편의 phenylephrine (PE) 유발 수축 반응을 증가시켰으며 methylene blue에 의해 더 강한 수축 반응의 증가가 관찰되었다. 이때 혈관 내피세포가 존재할 경우에 PE에 대한 혈관 반응성이 증가되는 경향을 나타내었다. 세균 내독소 투여에 의해 acetylcholine 유발 혈관 이완은 증가되는 경향을 나타내었고, 전처치한 L-NAME, methylene blue에 의해 혈관 절편의 acetylcholine (ACh) 유발 이완은 억제되었으며 methylene blue에 의해 현저히 억제되었다. 그러나 세균 내독소를 투여하지 않은 군의 ACh 유발 혈관 이완 반응은 methylene blue에 의해서만 억제되었다. 결론적으로 세균 내독소에 의한 혈관 반응성 감소와 혈관 이완 반응은 NO가 발생되어 guanylyl cyclase를 활성화하여 유발된다고 생각되며, 세균 내독소에 의한 효과는 L-arginine NO pathway 보다는 cyclic GMP 신호전달계를 경유한 경로에서 더 많은 영향을 받는것으로 사료된다.

• The Korean Journal of Physiology
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• 제28권2호
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• pp.225-231
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• 1994

The present study was undertaken to investigate the role of endogenous nitric oxide in renin release under different physiological conditions. In the first series of experiments, renin release was either inhibited by acute volume-expansion (VE) or stimulated by clipping one renal artery in the rat. VE was induced by intravenous infusion of saline (0.9% NaCl) up to 5% of the body weight over 45 min under thiopental (50 mg/kg, IP) anesthesia. VE caused a decrease of plasma renin concentration (PRC). With $N^G-nitro-L-arginine$ methyl ester $(L-NAME,\;5\;{\mu}g/kg\;per\;min)$ superadded to VE, PRC decreased further. The magnitude of increase in plasma atrial natriuretic peptide levels following VE was not affected by the L-NAME. In two-kidney, one clip rats, L-NAME-supplementation resulted in a decrease, and L-arginine-supplementation an increase of PRC. Plasma atrial natriuretic peptide levels were significantly lower in the L-arginine group than in the control. Blood pressure did not differ among the L-NAME, L-arginine, and control groups. In another series of experiments, the renin response to a blockade of NO synthesis was examined using in vitro preparations from isolated renal cortex. L-NAME significantly increased basal renin release, although it was without effect on the isoproterenol-stimulated release. These findings suggest that endogenous nitric oxide significantly contributes to the renin release. Since many factors may affect the renin release in vivo, an interaction between NO and renin under various pathophysiological states is to be further defined.

• 대한의생명과학회지
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• 제16권1호
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• pp.25-32
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• 2010

Sprague-Dawley(SD) rats were orally administered with $N^G$-nitro-L-arginine methyl ester(L-NAME) which inhibits or blocks the production of nitric oxide from L-arginine in vascular endothelial cells and vessel tissue to statistically examine the effects of nitric oxide on some physiological changes such as blood pressure and heart rate, and to confirm the apoptosis induced by the suppressed nitric oxide activity in some related organs under light microscope. Systolic blood pressure significantly increased 28.5% by the chronic treatment of L-NAME for 8 weeks (P<0.001), no significant difference, however, was observed in heart rate between the control group and the L-NAME-treated group regardless of their age. Hematoxylin-eosin staining showed some histological alterations only in kidney among the examined organs; heart, liver, pancreas, and adrenal gland from the L-NAME-treated group. TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) test showed a strong positive reaction, representing that the chronic treatment of L-NAME facilitates apoptosis, in the cortex and medulla of kidney, but not any significance detectable in the other organs. These results conclude that chronic treatment of L-NAME significantly increases blood pressure, and that the followed inhibition of nitric oxide synthesis occurs a typical inducement of apoptosis in kidney.

• The Korean Journal of Physiology and Pharmacology
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• 제7권2호
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• pp.73-77
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• 2003

The effects of nitric oxide on the vestibular function recovery following unilateral labyrinthectomy (UL) were studied. Sprague-Dawley male rats, treated with nitric oxide liberating agent sodium nitroprusside (SNP) and NOS inhibitor $N^G$-nitro-L-arginine methyl ester (L-NAME), were subjected to destruction of the unilateral vestibular apparatus, and then spontaneous nystagmus was observed in the rat. To explore the effects of nitric oxide on the neuronal excitability, whole cell patch clamp technique was applied on isolated medial vestibular nuclear neurons. The frequency of spontaneous nystagmus in SNP treated rats was lesser than that of spontaneous nystagmus in control animals. In contrast, pre-UL treatment with L-NAME resulted in a significant increase in spontaneous nystagmus frequency. In addition, SNP increased the frequency of spontaneous action potential in isolated medial vestibular nuclear neurons. Potassium currents of the vestibular nuclear neurons were inhibited by SNP. After blockade of calcium dependent potassium currents by high EGTA (11 mM) in a pipette solution, SNP did not inhibit outward potassium currents. 1H-[1,2,4] oxadiazolo [4,3-a] quinozalin-1-one (ODQ), a specific inhibitor of soluble guanylyl cyclase, inhibited the effects of SNP on the spontaneous firing and the potassium current. These results suggest that nitric oxide after unilateral labyrinthectomy would help to facilitate vestibular compensation by inhibiting calcium-dependent potassium currents through increasing intracellular cGMP, and consequently would increase excitability in ipsilateral vestibular nuclear neurons.

• The Korean Journal of Physiology and Pharmacology
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• 제5권1호
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• pp.41-46
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• 2001

To investigate the mutual relationship between angiotensin II (Ang II) and nitric oxide (NO) in paraventricular nucleus (PVN), Ang II receptor type Ia $(AT_{1A}),$ type Ib $(AT_{1B}),$ endothelial constitutive nitric oxide synthase (ecNOS), and neuronal constitutive nitric oxide synthase (ncNOS) mRNA levels of rat PVN were measured after unilateral carotid artery ligation. $AT_{1A}$ and $AT_{1B}$ mRNA levels were markedly elevated 6 hrs after unilateral carotid artery ligation. Losartan injection $(10\;{\mu}g/0.3\;{\mu}l)$ into the PVN augmented of the increment of $AT_{1A}$ and $AT_{1B}$ mRNAs It also increased ecNOS gene expression. In addition, $AT_{1B}$ mRNA levels increased after N-nitro-L-arginine methyl ester (L-NAME) injection $(50\;{\mu}g/0.3\;{\mu}l)$ into the PVN. These results suggest that Ang II and NO in the rat PVN may interplay, at least in part, through regulation of gene expression of ecNOS and $AT_{1B},$ respectively.

• 약학회지
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• 제57권5호
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• pp.376-381
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• 2013

The present study was undertaken to investigate the influence of curcumin on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that curcumin, the primary ingredient of Curcuma longa, plays a role in vascular relaxation through inhibition of Rho-kinase in rat aortae. Denuded arterial rings from male Sprague-Dawley rats were used and isometric tensions were recorded using a computerized data acquisition system. Interestingly, curcumin inhibited fluoride-induced contraction but didn't inhibit phorbol ester-induced contraction suggesting that additional pathways different from endothelial nitric oxide synthesis might be involved in the vasorelaxation. Furthermore, curcumin significantly inhibited fluoride-induced increases in pMYPT1 levels. On the other hand, it didn't significantly inhibit phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving inhibition of fluoride-induced MYPT1 phosphorylation. This study provides evidence that curcumin induces vascular relaxation through inhibition of Rho-kinase in rat aortae.

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 NEW STRATEGY FOR DRUG DEVELOPMENT IN POST-GENOMIC ERA(대한약학회)
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• pp.139.2-140
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• 2000

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 춘계총회 및 학술대회
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• pp.94.1-94.1
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• 2000