• Journal of Ginseng Research
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• v.16 no.3
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• pp.175-182
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• 1992

Intravenous administration of saponin from the root of Panax ginseng (red ginseng) lowered the blood pressure in a dose-dependent manner (10~100 mg/kg B.W) in anesthetized rats. Therefore, experiments were designed to study whether this lowering of blood pressure is associated with the release of endothelium-derived relaxing factor. Rings of thoracic aorta with and without endothelium were suspended for the measurement of isometric tension in organ chamber. All experiments were performed in the presence of indomethacin (10-5 M). Ginseng saponin (10-5~3$\times$10-4 g/ml) relaxed contractions induced by phenylephrine (10-5 M) in the aorta with endothelium but not in that without endothelium. Treatment of aortic rings with NG_monomethyl-L-arginine (L-NMMA 10-4 M for 30 min), a competive inhibitor of nitric oxide synthase and methylene blue (M.B., 3$\times$10-7 M for 30 min), an inhibitor of soluble guanylate cyclase, diminished the relaxation induced by ginseng saponin. In thoracic aortic rings from rats treated with ginseng saponin for 2 weeks intraperitoneally, the relaxation to acetylcholine was increased compared with non-ginseng treated rings. These data suggest that red ginseng saponin evokes hypotension and that vascular relaxations induced by red ginseng saponin are inediatpd by release of endothelium-derived relaxing factor.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.182-189
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• 1998

Administration of ginsenosides, a mixture of saponin extracted from Panax ginseng, decreased blood pressure in rat. Previous studies have shown that ginsenosides caused endothelium-dependent relaxation, which was associated with the formation of cyclic GMP, suggested that ginsenosides caused release of nitric oxide (NO) from the vascular endothelium. The aim of the present study was to characterize the endothelium-independent relaxation to ginsenosides in the isolated rat aorta. Ginsenosides caused a concentration-dependent relaxation of rat aortic rings without endothelium constricted with 25 mM KCI but affected only minimally those constricted with 60 mM KCI. Ginsenoside Rg3 (Rg3) was a more potent vasorelaxing agonist than total ginsenoside mixture and also the ginsenoside PPT and PPD groups. Relaxation to ginsenosides were markedly reduced by TEA, but not by glibenclamide. Rg3 significantly inhibited Cal'-induced concentration-contraction curves and the "50a2'influx in aortic rings incubated in 25 mM KCI whereas those responses were not affected in 60 mM KCI. Rg3 caused efflux of $"Rb in aortic rings that was inhibited by tetraethy- lammonium (TEA), an inhibitor of Ca"-dependent K'channels, but not by glibenclamide, an inhibitor of AfP-dependent K'channels. These findings indicate that ginsenosides may induce vasorelaxation via activation of Ca2'-dependent K'channels resulting in hyperpolarization of the vas- cular smooth muscle with subsequent inhibition of the opening of voltage-dependent Caf'channels. These effects could contribute to explain the red ginseng-associated vasodilation and the beneficial effect on the cardiovascular system.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.99-106
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• 2005

Background: Cyclic guanosine monophosphate (cGMP) and opioid receptors are involved in the modulation of nociception. Although the opioid receptors agonists are active in pain, the effect of an phospodiesterase inhibitor (zaprinast) for increasing the level of cGMP has not been thoroughly investigated at the spinal level. This study examined the effects of intrathecal zaprinast and morphine in a nociceptive test and we also examined the nature of the pharmacological interaction after the coadministration of zaprinast with morphine. The role of the nitric oxide (NO)-cGMP-potassium channel pathway on the effect of zaprinast was further clarified. Methods: Catheters were inserted into the intrathecal space of male SD rats. For the induction of pain, $50{\mu}l$ of 5% formalin solution was applied to the hindpaw. Isobolographic analysis was used for the evaluation of the drug interaction between zaprinast and morphine. Furthermore, NO synthase inhibitor ($_L-NMMA$), guanylyl cyclase inhibitor (ODQ) or a potassium channel blocker (glibenclamide) were intrathecally administered to verify the involvement of the NO-cGMP- potassium channel pathway on the antinociception effect of zaprinast. Results: Both zaprinast and morphine produced an antinociceptive effect during phase 1 and phase 2 in the formalin test. Isobolographic analysis revealed a synergistic interaction after the intrathecal administration of the zaprinast-morphine mixture in both phases. Intrathecal $_L-NMMA$, ODQ and glibenclamide did not reverse the antinociception of zaprinast in either phase. Conclusions: These results suggest that zaprinast, morphine and the mixture of the two drugs are effective against acute pain and they facilitated pain state at the spinal level. Thus, the spinal combination of zaprinast with morphine may be useful for the management of pain. However, the NO-sensitive cGMP-potassium channel pathway did not contribute to the antinocieptive mechanism of zaprinast in the spinal cord.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.28-38
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• 2008

In traditional oriental medicine, Gentianae Radix has been used clinically for clearing away 'heat', removing dampness and purging fire in the liver and gall bladder. However, there has been a lack of studies regarding the effects of Gentianae Radix on the immunological activities. The present study was conducted to evaluate the effect of Gentianae Radix on the regulatory effects of cytokines and nitric oxide(NO) for the immunological activities in Raw 264.7 cells. After the treatment of Gentianae Radix MeOH extract, cell viability was measured by MTT assay, and NO production was monitored by measuring the nitrite content in culture medium. The expression of COX-2 and iNOS was determined by immunoblot analysis, and the content of levels of cytokines in media was analyzed by ELISA kit. Results provided evidence that Gentianae Radix inhibited the production of nitrite and nitrate (NO), inducible nitric oxide synthase (iNOS), $interleukin-l{\beta}$ $(IL-l{\beta})$ and IL-6, and the activation of phospholylation of inhibitor ${\kappa}B{\alpha}$ ($p-I {\kappa}B{\alpha}$) in Raw 264.7 cells activated with lipopolysaccharide (LPS). These findings suggest that Gentianae Radix can make anti-inflammatory effect, which may playa role in adjunctive therapy.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.225-232
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• 1998

To investigate the possible involvement of outward potassium ($K^+$) currents in nitric oxide-induced relaxation in intestinal smooth muscle, we used whole-cell patch clamp technique in freshly dispersed guinea-pig ileum longitudinal smooth muscle cells. When cells were held at -60 mV and depolarized from -40 mV to -50 mV in 10 mV increments, sustained outward $K^+$ currents were evoked. The outward $K^+$ currents were markedly increased by the addition of 10 ${\mu}M$ sodium nitroprusside (SNP). 10 ${\mu}M$ S-nitroso-N-acetylpenicillamine (SNAP) and 1 mM 8-Bromo-cyclic GMP (8-Br-cGMP) also showed a similar effect to that of SNP. 1 mM tetraethylammonium (TEA) significantly reduced depolarization-activated outward $K^+$ currents. SNP-enhanced outward $K^+$ currents were blocked by the application of TEA. High EGTA containing pipette solution (10 mM) reduced the control currents and also inhibited the SNP-enhanced outward $K^+$ currents. 5 mM 4-aminopyridine (4-AP) significantly reduced the control currents but showed no effect on SNP-enhanced outward $K^+$ currents. 0.3 ${\mu}M$ apamin and 10 ${\mu}M$ glibenclamide showed no effect on SNP-enhanced outward $K^+$ currents. 10 ${\mu}M$ 1H-[1,2,4]oxadiazolo [4,3-a]quinoxaline-1-one (ODQ), a specific inhibitor of soluble guanylate cyclase, significantly blocked SNP-enhanced $K^+$ currents. We conclude that NO donors activate the $Ca^{2+}-activated$ $K^+$ channels in guinea-pig ileal smooth muscle via activation of guanylate cyclase.

• Preventive Nutrition and Food Science
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• v.17 no.1
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• pp.22-28
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• 2012

Melaleuca leucadendron L. has been used as a tranquilizing, sedating, evil-dispelling and pain-relieving agent. We examined the effects of M. leucadendron L. extracts on oxidative stress and inflammation. M. leucadendron L. was extracted with methanol (MeOH) and then fractionated with chloroform ($CHCl_3$) and butanol (BuOH). Antioxidant activity of the MeOH extract and BuOH fraction were higher than that of both ${\alpha}$-tocopherol and butyrated hydroxytoluene (BHT). Total phenol content in the extracts of M. leucadendron L., especially the BuOH fraction, well correlated with the antioxidant activity. The anti-inflammatory activity of BuOH extracts were investigated by lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production, and cyclooxygenase-2 (COX-2) expression in RAW 264.7 macrophages. The BuOH fraction significantly inhibited LPS-induced NO and $PGE_2$ production. Furthermore, BuOH extract of M. leucadendron L. inhibited the expression of COX-2 and iNOS protein without an appreciable cytotoxic effect on RAW264.7 cells. The extract of M. leucadendron L. also suppressed the phosphorylation of inhibitor ${\kappa}B{\alpha}$ ($I{\kappa}B{\alpha}$) and its degradation associated with nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activation. Furthermore, BuOH fraction inhibited LPS-induced NF-${\kappa}B$ transcriptional activity in a dose-dependent manner. These results suggested that M. leucadendron L. could be useful as a natural antioxidant and anti-inflammatory resource.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.190-197
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• 2005

Advanced glycation end products (AGE) have been implicated in the pathogenesis of diabetic complications including nephropathy. However, the role of AGE in the activation of mesangial cells cultured under high glucose has not been elucidated. The effects of aminoguanidine, which prevents formation of AGE and protein cross-linking, on the synthesis of $TGF-{\beta}1$ and fibronectin by rat mesangial cells cultured under high glucose for 2 weeks were examined and compared with the effects of $N^G$-nitro-L-arginine methyl ester (NAME), a selective nitric oxide synthase inhibitor, because aminoguanidine also inhibits the inducible nitric oxide synthase. Culture of mesangial cells in 30 mM (high) glucose for 2 weeks induced 1.5-fold (ELISA) and 1.9-fold (Western blot analysis) increase in AGE in the culture media compared to 5.6 mM (control) glucose. Northern blot analysis revealed 1.5-fold increase in $TGF-{\beta}1$ and 1.7-fold increase in fibronectin mRNA expression in cells cultured under high glucose compared to control glucose. Increases in mRNA expression were followed by increased protein synthesis. Mink lung epithelial cell growth inhibition assay revealed 1.4-fold increase in $TGF-{\beta}1$ protein in high glucose media compared to control. Fibronectin protein also increased 2.1-fold that of control glucose by Western blot analysis. Administration of aminoguanidine suppressed AGE formation in a dose dependent manner and at the same time suppressed $TGF-{\beta}1$ and fibronectin synthesis by mesangial cells cultured in both control and high glucose. In contrast, NAME did not affect high glucose-induced changes. These findings support a role for AGE in high glucose-induced upregulation of $TGF-{\beta}1$ and fibronectin synthesis by mesangial cells.

• Biomolecules & Therapeutics
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• v.5 no.2
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• pp.202-210
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• 1997

Protective effect of DA-9601, an extract of Artemisia Herb, against ethanol-induced gastric mucosal injury was evaluated in rats. In the prophylactic study, DA-9601 exhibited total protection (99.4%) against absolute ethanol-induced gastropathy, And the protective effect of DA-9601 lasted up to 2 hours, which was longer than those of other contemporary mucoprotectants. In the treatment study, DA-9601 significantly facilitated the healing of 70% ethanol-induced mucosal damage, which was superior to cetraxate, a commonly used anti-ulcer drug. The mechanisms of mucoprotection of DA-9601 were also assessed. DA-9601 increased the release of prostaglandin E$_2$ from murine neutrophils in a dose-dependent manner in vitro. The cytoprotective effect of DA-9601 against ethanol-induced mucosal damage was significantly diminished by the concommitant injection of N$\omega$-nitro-L-arginine methyl ester (L-NAME, 5 mg/kg, i.v.), a non-specific nitric oxide (NO) synthase inhibitor, while it was not affected by preinjection of indomethacin (5 mg/kg, s.c.), a prostaglandins-depletor. And it was found that DA-9601 significantly enhanced adaptive cytoprotective action of 10% ethanol against absolute ethanol (56.9$\pm$6.5 vs 23.0$\pm$3.3 mm$^2$, p<0.05, mean$\pm$SEM), though its exact underlying mechanism remains to be clarified. The present fin[lings demonstrate that DA-9601 exerts gastroprotecticv actions for the stomach against ethanol through several different underlying mechanisms, in which prostanglandins and NO are involved. In conclusion, the results obtained suggest that DA-9601 can be useful both in prevention and treatment of ethanol-induced gastric damage.

• Nutrition Research and Practice
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• v.14 no.2
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• pp.109-116
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• 2020

BACKGROUND/OBJECTIVES: Excessive intake of simple sugars induces obesity and increases the risk of inflammation. Thus, interest in alternative sweeteners as a sugar substitute is increasing. The purpose of this study was to determine the effect of saccharin on inflammation in 3T3-L1 adipocytes. MATERIALS/METHODS: 3T3-L1 preadipocytes were differentiated into adipocytes. The adipocytes were treated with saccharin (0, 50, 100, and 200 ㎍/mL) for 24 h. Inflammation was induced by exposure of treated adipocytes to lipopolysaccharide (LPS) for 18 h and cell proliferation was measured. The concentration of nitric oxide (NO) was measured by using Griess reagent. Protein expressions of nuclear factor kappa B (NF-κB) and inhibitor κB (IκB) were determined by western blot analysis. The mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin 1β (IL-1β), interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-α (TNF-α) were determined by real-time PCR. RESULTS: Compared with the control group, the amount of NO and the mRNA expression of iNOS in the LPS-treated group were increased by about 17.6% and 46.9%, respectively, (P < 0.05), and those parameter levels were significantly decreased by saccharin treatment (P < 0.05). Protein expression of NF-κB was decreased and that of IκB was increased by saccharin treatment (P < 0.05). Saccharin decreased the mRNA expression of COX-2 and the inflammation cytokines (IL-1β, IL-6, MCP-1, and TNF-α) (P < 0.05). CONCLUSIONS: The results of this study suggest that saccharin can inhibit LPS-induced inflammatory responses in 3T3-L1 adipocytes via the NF-κB pathway.

• The Korean Journal of Pain
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• v.14 no.2
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• pp.225-230
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• 2001

Background: Opioids such as morphine are widely used in the treatment for pain, but chronic treatment with morphine can be complicated by the development of tolerance. The mechnisms of tolerance were still not completely understood, but recently it has been reported that NOS inhibitors can prevent development of morphine tolerance in animals. The present study accessed the possible role of supraspinal NO on antinociceptive effect of morphine in morphine tolerance using a highly specific inhibitor of the neuronal isoform of NOS, 1-(2-trifluoromethylphenyl) imidazole (TRIM). Methods: Thirty two male SD rats (300 g) were prepared with intracerebroventricular (icv) and IV cannulae. We administrated IV morphine, 3 mg/kg, daily for 4 days, resulting in tolerance. On the fifth day, a challenge dose of morphine, 3 mg/kg, was administered following pretreatment with icv TRIM, $10{\mu}g$. We also evaluated the antinociceptive effect of icv TRIM alone and the effect on a single dose of morphine (3 mg/kg) in morphine nave rats. Antinociception from morphine was determined by response to intraplantar injection of 5% formalin $100{\mu}l$ was qualified as the number of flinches in the first 0-10 min (first phase), 10-40 min Phase IIa, and 40-60 min (Phase IIb). Results: Pretreatment with icv TRIM significantly enhanced the antinociceptive effects of systemically administered morphine in morphine tolerant rats. The antinociceptive effect of morphine in opioid nave rats was also significantly increased by pretreatment with icv TRIM. Conclusions: Our results further support the hypothesis that supraspinal NO modulates morphine-sensitive nociceptive process in morphine tolerance due to chronic intravenous administration.