• 대한수의학회지
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• 제43권4호
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• pp.551-554
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• 2003

Nitric oxide synthase (NOS) has been reported in uterus. We examined the expression of the NOS isoforms, constitutive endothelial (eNOS) and inducible NOS (iNOS), in bovine uterus by immunohistochemistry. eNOS immunoreactivity was localized predominantly to the endothelial cells that line uterine microvessels and to endometrial glandular epithelial cells, but was barely detectable in endometrial stromal cells. iNOS immunostaining was detected in glandular epithelial and stromal cells in the endometrium and in the endothelial cells of myometrial blood vessels. These findings suggest that both eNOS and iNOS may play important roles in the physiology of the uterus, possibly by generating NO.

• The Korean Journal of Physiology and Pharmacology
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• 제7권5호
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• pp.283-287
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• 2003

While nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is beneficial for host survival, it is also detrimental to the host. Thus, regulation of iNOS gene expression may be an effective therapeutic strategy for the prevention of unwanted reactions at various pathologic conditions. During the screening process for the possible iNOS regulators, we observed that esculetin is a potent inhibitor of cytokine-induced iNOS expression. The treatment of 3T3-L1 adipocytes with the tumor necrosis factor-${\alpha}$ (TNF) induced iNOS expression, leading to enhanced NO production. TNF-induced NO production was inhibited by esculetin in a dose-dependent manner. Esculetin inhibited the TNF-induced NO production at the transcriptional level through suppression of iNOS mRNA and subsequent iNOS protein expression. These results suggest esculetin, a component of natural products, as a naturally occurring, nontoxic means to attenuate iNOS expression and NO-mediated cytotoxicity.

• Toxicological Research
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• 제19권1호
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• pp.33-37
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• 2003

Asiaticoside has been tested for the ability as an anti-inflammatory drug using lipopolysaccharide (LPS)-stimulated macrophage cell line (RAW 264.7 cell). LPS treatment induced dramatically inducible nitric oxide synthase (iNOS) in RAW cells. However, asiaticoside inhibited LPS-stimulated iNOS induction in a concentration-dependent manner. Especially, higher concentrations (＞50 $\mu\textrm{M}$) of asiaticoside completely blocked iNOS induction. In addition, LPS-stimulated expression of inducible cyclooxygenase (COX-2) and interleukin-1 $\alpha$ (IL-1 $\alpha$) was inhibited by asiaticoside treatment. Asiaticoside up to 50 $\mu\textrm{M}$ still required to inhibit COX-2 and IL-1 $\alpha$ induced by LPS. Consistent with these findings, treatment with asiaticoside suppressed do novo synthesis and cellular accumulation of prostaglandin $E_2$ to a lesser extent, suggesting that asiaticoside blocked the induction as well as the activity of COX-2 These results suggest the possibility that asiaticoside may be effective therapeutic agents for septic shock and other inflammatory diseases.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.1048-1053
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• 2009

The present study was conducted to determine the effects of chitosan on nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in serum, and relative expression of iNOS mRNA in the duodenum, jejunum, and ileum of broiler chickens. A total of 240 one-day-old Arbor Acre mixed-sex broiler chickens were randomly allotted to six dietary treatments with five replicates in each treatment and eight chickens in each replicate. The broiler chickens in the six treatments were fed the basal diet supplemented with 0 (control), 0.05, 0.2, 0.5, 1.0 or 2.0 g/kg chitosan. The trial lasted for 42 days. The results showed that dietary chitosan enhanced NO content and iNOS activity in serum as well as iNOS mRNA expression in the duodenum and ileum of broiler chickens in a quadratic dose-dependent manner (p<0.05), and improved jejunum iNOS mRNA expression in a quadratic dose-dependent manner (p<0.10) with increasing addition of chitosan. Chicks fed a diet containing 0.5-1.0 g/kg chitosan had higher NO content and iNOS activity in serum as well as small-intestinal iNOS mRNA expression compared with birds given the control diet, but positive effects of chitosan tended to be suppressed when addition of chitosan in the diet was increased to 2.0 g/kg. These results implied that there was a threshold level of chitosan inclusion beyond which progressive reductions in serum NO content and small intestinal iNOS expression occured, and the regulation of chitosan on immune functions in chickens is probably associated with activated expression of iNOS and NO secretion.

• 대한의생명과학회지
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• 제19권3호
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• pp.180-187
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• 2013

Hypoxia is an integral part of the environment during luteolysis. In this study we examined whether hypoxia could directly stimulate endothelial cells to produce nitric oxide (NO). Endothelial cells were cultured in hypoxic (5% $O_2$) or normoxic (20% $O_2$) conditions and the levels of total NO, inducible NO and endothelial NO was measured. We found that hypoxia but not normoxia upregulated NO production. The increased NO levels correlated with increased inducible NO synthase (iNOS) expression whereas expression of endothelial NOS (eNOS) expression remained constant. Addition of the iNOS specific inhibitor 1400W to hypoxic cultures prevented NO production suggesting that hypoxia-induced NO production in endothelial cells was due mainly to upregulation of iNOS. We also found that prostaglandin $F_{2{\alpha}}$ (PGF) production was unaffected by hypoxia suggesting that upregulation of NO was not due to increased synthesis of PGF. In summary, we report that endothelial cells cultured under hypoxic conditions produce NO via the iNOS pathway. This study provides the importance of the relation between the hypoxic environment and the induction of NO by endothelial cells during regression of the corpus luteum in the ovary.

• Archives of Pharmacal Research
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• 제26권4호
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• pp.301-305
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• 2003

Nitric oxide (NO) is an important bioactive agent that mediates a wide variety of physiological and pathophysiological events. NO overproduction by inducible nitric oxide synthase (iNOS) results in severe hypotension and inflammation. This investigation is part of a study to discover new iNOS inhibitors from medicinal plants using a macrophage cell culture system. Two sesquiterpenes (1 and 2) were isolated from Artemisia iwayomogi (Compositae) and were found to inhibit NO synthesis ($IC_{50} 3.64 \mu g/mL and 2.81 \mu$g/mL, respectively) in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Their structures were identified as 3-Ο-methyl-iso-secotanapartholide (1) and iso-secotanapartholide (2). Compounds 1 and 2 inhibited the LPS-induced expression of the iNOS enzyme in the RAW 264.7 cells. The inhibition of NO production via the down regulation of iNOS expression may substantially modulate the inflammatory responses.

• 대한의생명과학회지
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• 제25권2호
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• pp.196-200
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• 2019

Effect of retinoids, i.e., all-trans retinoic acid and 13-cis retinoic acid, on the activity of nitric oxide synthase (NOS) was evaluated in human malignant keratinocytes to examine the possible correlation of retinoids with NOS activities. All-trans retinoic acid and 13-cis retinoic acid did not alter the nitric oxide (NO) production. However, in the presence of lipopolysaccharide (LPS, $1{\mu}g/mL$), they significantly increased NO release in a dose-dependent manner until 48 h at concentrations of $50{\sim}100{\mu}M$. The degree of upregulation of NO by all-trans retinoic acid and 13-cis retinoic acid increased up to 35% and 37%, respectively, compared to that by the control, which demonstrated the upregulation of LPS-inducible nitric oxide synthase (iNOS)-dependent generation of NO as well as showing a crucial link between retinoids-induced activity and NOS. Findings of this study now suggest that the upregulation of LPS-iNOS activity may be associated with modulation of retinoids-induced control of cellular developmental processes, which may produce new therapeutics of retinoids in the complexity of how NO affects human keratinocytes.

• Natural Product Sciences
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• 제23권2호
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• pp.92-96
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• 2017

A sesquiterpene was purified from Artemisia iwayomogi methanolic extract during the course of searching anti-inflammatory principle from medicinal plants. A sesquiterpene identified as armefolin inhibited the production of nitric oxide (NO) and attenuated inducible nitric oxide synthase (iNOS) protein level in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Armefolin also down-regulated mRNA expressions of iNOS and pro-inflammatory cytokines, interleukin-$1{\beta}$ and interleukin-6 in LPS-activated macrophages. Moreover, armefolin suppressed the degradation of inhibitory-${\kappa}B{\alpha}$ (I-${\kappa}B{\alpha}$) in LPS-activated macrophages. These data suggest that armefolin from A. iwayomogi can suppress the LPS-induced production of NO and the expression of iNOS gene through inhibiting the degradation of I-${\kappa}B{\alpha}$. Taken together, armefolin from A. iwayomogi might be a candidate as promising anti-inflammatory agent.

• 약학회지
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• 제48권6호
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• pp.309-316
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• 2004

The present investigation was undertaken to find out the anticancer activity of monoterpene compounds. Monoterpenes showed generally the inhibitory effect on the proliferation o f L1210 cancer cells (cytotoxicity). Geraniol was found to exibit the most potent cytotoxic effect on L1210 cells with an IC50 values of $0.67{\mu}g/ml$. On the other hand, geraniol proved to be capable of stimulating the macrophage proliferation (135% of control). When the life prolonging activity of geraniol by daily oral administration of 0.1~10${\mu}g/10{\mu}l/20$ g body weight to Sarcoma 180 bearing ICR mouse was examined, there was also a significant elevation of survival (best result of 134% of control). The contradictory effects of geraniol on the proliferation of L1210 cells and macrophages proved to be accompanied by the coincident alterations of RNS (reactive nitrogen species) related enzymes activities such as inducible nitric oxide synthase (Inos) in macrophages and ROS (reactive oxygen species) related enzymes activities such as superoxide dismutase (SOD) in L1210 cells, respectively.

• 한국식품과학회지
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• 제46권4호
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• pp.511-515
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• 2014

각종 염증성 질환 및 패혈증으로 인한 치명적인 저혈압을 예방치료하는 약물 개발을 위한 기초 연구로서 유도성 NOS (inducible nitric oxide synthase, iNOS) 에 의한 NO의 과다 생성을 저해하는 성분을 천연물로부터 찾아내고자 본 연구를 수행하였다. NO 생성 저해활성의 검정은 대식세포주인 RAW 264.7 세포를 LPS로 활성화한 후, 유도되는 iNOS에 의해 생성되는 NO를 Griess 시약을 이용해 $NO_2{^-}$의 형태로 정량하였다. 또한 Western blot 실험 및 RT-PCR 실험을 시행하여 iNOS의 mRNA의 발현 및 단백 합성에 대한 영향을 조사하였다. 고량강(Alpinia officinarum Hance, Zingiberaceae)의 메탄올 추출물로부터 극성에 따른 용매 분획을 시행하여 활성성분을 분리하고 분광학적 분석법을 이용하여 분리한 단일성분이 flavonol 구조인 3,5,7-trihydroxy-2-phenylchromen-4-one (galangin, GLG)임을 확인하였다. 작용기전을 알아보기 위해, Western blot 및 RT-PCR 실험결과, 분리한 flavonol 성분(GLG)의 NO 생성저해 활성은 iNOS mRNA발현을 저해하여 iNOS 효소 단백질의 생성이 억제됨에 기인하는 것으로 확인하였다. 따라서, 고량강 추출물로부터 분리한 flavonol 화합물(GLG)이 iNOS 발현의 억제를 통해 다량의 NO 생산을 저해함으로써, 고량강(Alpinia officinarum)의 NO 과량생성과 관련된 염증성 질환에 대한 응용 가능성이 클 것으로 기대된다.