Antitumor Potential of Sericite Treatment Mediated by Cell Cycle Arrest in Triple-Negative MDA-MB231 Breast Cancer Cells.

Breast cancer is the most common cancer and the leading cause of cancer-related mortality among females worldwide. Triple-negative breast cancer (TNBC) accounts for about 10-15% of all breast cancers and is usually more aggressive and has a poorer prognosis. Sericite has been known to have antitumor and immune-stimulatory effects. Although the chemopreventive potential of sericite has been demonstrated in other cancers, its molecular pathways in TNBC still require investigation. Thus, in the present study, the antitumor mechanism of sericite against MDA-MB231 breast cancer cells was examined in vitro and in an in vivo xenograft mouse model. Sericite treatment reduced cell proliferation and cell proliferation marker proliferating cell nuclear antigen (PCNA) in MDA-MB231 cells. It also decreased the total cell number and arrested cells in the G0/G1 phase of the cell cycle with an increase in the phosphorylation of P53 and upregulation of cell cycle regulatory proteins P21 and P16. In addition, sericite treatment also induced apoptosis signaling, which was evident by the upregulation of apoptotic protein markers cleaved caspases 3 and 9. A reduction in reactive oxygen species (ROS), NADPH oxidase 4 (NOX4), p22phox, and heat shock proteins (HSPs) was also observed. Similar results were obtained in vivo with significantly reduced tumor volume in sericite-administered mice. Collectively, these findings suggest that sericite has antitumor potential based on its property to induce cell cycle arrest and apoptotic cell death and therefore could serve as a potential therapeutic agent and crucial candidate in anticancer drug development for TNBC.

CRIF1 Deficiency Increased Homocysteine Production by Disrupting Dihydrofolate Reductase Expression in Vascular Endothelial Cells.

Elevated plasma homocysteine levels can induce vascular endothelial dysfunction; however, the mechanisms regulating homocysteine metabolism in impaired endothelial cells are currently unclear. In this study, we deleted the essential mitoribosomal gene CR6 interacting factor 1 (CRIF1) in human umbilical vein endothelial cells (HUVECs) and mice to induce endothelial cell dysfunction; then, we monitored homocysteine accumulation. We found that CRIF1 downregulation caused significant increases in intracellular and plasma concentrations of homocysteine, which were associated with decreased levels of folate cycle intermediates such as 5-methyltetrahydrofolate (MTHF) and tetrahydrofolate (THF). Moreover, dihydrofolate reductase (DHFR), a key enzyme in folate-mediated metabolism, exhibited impaired activity and decreased protein expression in CRIF1 knockdown endothelial cells. Supplementation with folic acid did not restore DHFR expression levels or MTHF and homocysteine concentrations in endothelial cells with a CRIF1 deletion or DHFR knockdown. However, the overexpression of DHFR in CRIF1 knockdown endothelial cells resulted in decreased accumulation of homocysteine. Taken together, our findings suggest that CRIF1-deleted endothelial cells accumulated more homocysteine, compared with control cells; this was primarily mediated by the disruption of DHFR expression.

Protective Role of Dietary Capsanthin in a Mouse Model of Nonalcoholic Fatty Liver Disease.

Capsanthin is the main carotenoid compound in red paprika (Capsicum annuum L.). However, little is known about the beneficial effects of capsanthin in nonalcoholic fatty liver disease (NAFLD). In this study, the hepatoprotective activity of capsanthin was investigated in a mouse model of NAFLD. Apolipoprotein-E knockout mice were fed with normal diet, Western-type diet (WD, NAFLD model), WD with capsanthin (0.5 mg/kg of body weight/day, CAP), WD with capsanthin-rich extract (25 mg/kg of body weight/day; CRE), or WD with red paprika powder (25 mg/kg of body weight/day, RPP) for 12 weeks. The carotenoid content in CRE or RPP was analyzed using ultraperformance liquid chromatography. The capsanthin concentration in CRE was 2067 mg/100 g of dry weight, which was 63% of total carotenoids. The oral administration of CRE or capsanthin significantly reduced the WD-induced increase in body weight and lipid accumulation in the liver (vs. the RPP group). In addition, CRE or capsanthin significantly inhibited the WD-induced increase in cholesterol and low-density lipoprotein levels. Furthermore, CRE or capsanthin showed reduced levels of plasma alanine and aspartate aminotransferase (ALT and AST, respectively), suggesting a steatohepatitis protective effect. Capsanthin regulated mRNA levels of peroxisome proliferator-activated receptor alpha (Pparα), carnitine palmitoyltransferase 1A (Cpt1a), acyl-CoA oxidase 1 (Acox1), and sterol regulatory element binding protein-1c (Srebp1c), which are associated with hepatic fatty acid metabolism. Overall, our results suggest that the capsanthin of red paprika plays a protective role against hepatic steatosis/steatohepatitis in NAFLD.

Effect of a new herbal composition comprised of red clover and hop extract on human endothelial cell damage and vasorelaxant activity.

Hormone replacement therapy may cause various side effects, including enhancing the risk of cardiovascular disease (CVD) in postmenopausal women. Here, we investigated the effect of red clover and hop extract combination (RHEC) on estrogen receptor (ER) binding and endothelial function of human umbilical vein endothelial cells (HUVECs) to develop an herbal agent for reducing the risk of CVDs. In ER competitor assay, RHEC showed binding affinity toward ERα and ERß with IC50 values of 5.92 µg/ml and 1.66 µg/ml, respectively. In HUVECs, RHEC significantly increased the cell viability and reduced the reactive oxygen species production against oxidative stress-induced damage. We also showed that RHEC increased the NO production through upregulating the endothelial nitric oxide synthase expression via ER activation in estrogen depleted condition. In particular, RHEC showed greater efficacy with increase in NO and decrease in endothelin-1 than red clover or hop treatment alone. Additionally, 0.3-0.5 mg/ml of RHEC-induced vasorelaxation of rat aortic rings precontracted by phenylephrine. PRACTICAL APPLICATIONS: Recently, a large interest has grown in the synergistic effects of phytochemicals for better therapies to treat various diseases. Red clover and hop are well-known edible plants which are widely used to help relieve postmenopausal symptoms including CVD. However, their combination has not been studied so far. For the first time, we demonstrated that RHEC, a new herbal combination comprising the extracts from red clover and hop, appeared to be effective in protection of endothelial function against oxidative stress and estrogen depletion. Therefore, RHEC could be a potent herbal agent for reducing the risk of endothelial damage.

Far-Infrared-Emitting Sericite Board Upregulates Endothelial Nitric Oxide Synthase Activity through Increasing Biosynthesis of Tetrahydrobiopterin in Endothelial Cells.

Far-infrared ray (FIR) therapy has been reported to exert beneficial effects on cardiovascular function by elevating endothelial nitric oxide synthesis (eNOS) activity and nitric oxide (NO) production. Tetrahydrobiopterin (BH4) is a key determinant of eNOS-dependent NO synthesis in vascular endothelial cells. However, whether BH4 synthesis is associated with the effects of FIR on eNOS/NO production has not yet been investigated. In this study, we investigated the effects of FIR on BH4-dependent eNOS/NO production and vascular function. We used FIR-emitting sericite boards as an experimental material and placed human umbilical vein endothelial cells (HUVECs) and Sprague-Dawley rats on the boards with or without FIR irradiation and then evaluated vascular relaxation by detecting NO generation, BH4 synthesis, and Akt/eNOS activation. Our results showed that FIR radiation significantly enhanced Akt/eNOS phosphorylation and NO production in human endothelial cells and aorta tissues. FIR can also induce BH4 storage by elevating levels of enzymes (e.g., guanosine triphosphate cyclohydrolase-1, 6-pyruvoyl tetrahydrobiopterin synthase, sepiapterin reductase, and dihydrofolate reductase), which ultimately results in NO production. These results indicate that FIR upregulated eNOS-dependent NO generation via BH4 synthesis and Akt phosphorylation, which contributes to the regulation of vascular function. This might develop potential clinical application of FIR to treat vascular diseases by augmenting the BH4/NO pathway.

Anthocyanin-Rich Extract from Red Chinese Cabbage Alleviates Vascular Inflammation in Endothelial Cells and Apo E-/- Mice.

Anthocyanins, the most prevalent flavonoids in red/purple fruits and vegetables, are known to improve immune responses and reduce chronic disease risks. In this study, the anti-inflammatory activities of an anthocyanin-rich extract from red Chinese cabbage (ArCC) were shown based on its inhibitory effects in cultured endothelial cells and hyperlipidemic apolipoprotein E-deficient mice. ArCC treatment suppressed monocyte adhesion to tumor necrosis factor-α-stimulated endothelial cells. This was validated by ArCC's ability to downregulate the expression and transcription of endothelial adhesion molecules, determined by immunoblot and luciferase promoter assays, respectively. The regulation of adhesion molecules was accompanied by transcriptional inhibition of nuclear factor-κB, which restricted cytoplasmic localization as shown by immunocytochemistry. Administration of ArCC (150 or 300 mg/kg/day) inhibited aortic inflammation in hyperlipidemic apolipoprotein E-deficient mice, as shown by in vivo imaging. Immunohistochemistry and plasma analysis showed that the aortas from these mice exhibited markedly lower leukocyte infiltration, reduced plaque formation, and lower concentrations of blood inflammatory cytokines than those observed in the control mice. The results suggest that the consumption of anthocyanin-rich red Chinese cabbage is closely correlated with lowering the risk of vascular inflammatory diseases.

Ethanol Extract of Brassica rapa ssp. pekinensis Suppresses Tumor Necrosis Factor-α-Induced Inflammatory Response in Human Umbilical Vein Endothelial Cells.

Brassica rapa L. ssp. pekinensis, commonly known as Chinese cabbage, is a cruciferous vegetable traditionally consumed in east Asia. Although its habitual consumption could account for the low incidence of chronic vascular inflammation, the therapeutic and protective potential of phytochemicals derived from Chinese cabbage has been poorly studied. In this study, we identified the phenolic compounds, kaempferol and quercetin, from the ethanol extract of Chinese cabbage (EtCC). We show for the first time that EtCC contains effective phytochemicals that suppress tumor necrosis factor (TNF)-α-induced inflammatory response in human umbilical vein endothelial cells. The EtCC inhibited TNF-α-induced monocyte adhesion to endothelial cells in a dose-dependent manner. The antiadhesive activity of EtCC directly correlated with downregulation of expression and transcription of vascular cell adhesion molecule-1 (VCAM-1). It was caused by an Nrf-2-dependent mechanism, leading to activation of antioxidant responsive element-driven promoter. Taken together, these results suggest that EtCC inhibits the expression of TNF-α-induced adhesion molecules through the indirect transcriptional modulation of VCAM-1 in endothelial cells. In conclusion, regular consumption of vegetables containing dietary phytochemicals might be a potential therapeutic strategy to protect against various stresses, to prevent several pathological conditions, and to treat chronic vascular inflammation, such as atherosclerosis.

Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation.

PURPOSE: Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism. MATERIALS AND METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay. RESULTS: SIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. N(G)-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition. CONCLUSION: These findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions.

Ulmus davidiana ethanol extract inhibits monocyte adhesion to tumor necrosis factor-alpha-stimulated endothelial cells.

BACKGROUND: Ulmus davidiana var. japonica Rehder (UD) has long been used in traditional folk medicine in Asia. This study is designed to investigate the antiadhesive activity of the ethanol extract of UD (UDE) and its underlying mechanisms in cultured endothelial cells. METHODS: The dried root bark of UD was extracted with 80% (v/v) ethanol. The antiadhesive activity of the UDE was investigated in cultured human umbilical vein endothelial cells and human embryonic kidney epithelial 293T (HEK 293T) cells stably transfected with pGL3-vascular cell adhesion molecule (VCAM)-1-luc. Monocyte adhesion in endothelial cells was induced by tumor necrosis factor-alpha (TNF-α), and the protective effects of UDE on monocyte-endothelial cell adhesion, VCAM-1 expression, reactive oxygen species production, and nuclear factor-κB activity were determined. RESULTS: Exposure to UDE at a concentration of 3-30 µg/mL for 24 hours produced no detectable cytotoxicity in human umbilical vein endothelial cells, but it significantly inhibited TNF-α-induced monocyte adhesion and VCAM-1 expression. TNF-α treatment of HEK 293T/VCAM-1-luc cells resulted in increased luciferase activity of the VCAM-1 promoter, which was inhibited by treatment with UDE. Additionally, TNF-α-induced reactive oxygen species generation, nuclear translocation of nuclear factor-κB, and IκBα degradation in human umbilical vein endothelial cells were effectively reduced by treatment with 30 µg/mL of UDE. CONCLUSION: Our results indicated that UDE treatment inhibited TNF-α-induced monocyte adhesion in endothelial cells, suggesting that UD may reduce vascular endothelial inflammation.

A Novel Arginase Inhibitor Derived from Scutellavia indica Restored Endothelial Function in ApoE-Null Mice Fed a High-Cholesterol Diet.

Elevated endothelial arginase activity decreases nitric oxide (NO) production by competing with the substrate l-arginine, previously reported, and reciprocally regulating endothelial nitric oxide synthase (eNOS) activity. Thus, arginase inhibitors may help treat vascular diseases associated with endothelial dysfunction. A screening of metabolites from medicinal plants revealed that (2S)-5,2',5'-trihydroxy-7,8-dimethoxy flavanone (TDF) was a noncompetitive inhibitor of arginase. We investigated whether TDF reciprocally regulated endothelial NO production and its possible mechanism. TDF noncompetitively inhibited arginase I and II activity in a dose-dependent manner. TDF incubation decreased arginase activity and increased NO production in human umbilical vein endothelial cells and isolated mouse aortic vessels and reduced reactive oxygen species (ROS) generation in the endothelium of the latter. These TDF-mediated effects were associated with increased eNOS phosphorylation and dimerization but not with changes in protein content. Endothelium-dependent vasorelaxant responses to acetylcholine (Ach) were significantly increased in TDF-incubated aortic rings and attenuated by incubation with soluble guanylyl cyclase inhibitor. Phenylephrine-induced vasoconstrictor responses were markedly attenuated in TDF-treated vessels from wild-type mice. In atherogenic-prone ApoE(-/-) mice, TDF attenuated the high-cholesterol diet (HCD)-induced increase in arginase activity, which was accompanied by restoration of NO production and reduction of ROS generation. TDF incubation induced eNOS dimerization and phosphorylation at Ser1177. In addition, TDF improved Ach-dependent vasorelaxation responses and attenuated U46619-dependent contractile responses but did not change sodium nitroprusside-induced vasorelaxation or N-NAME-induced vasoconstriction. The findings suggest that TDF may help treat cardiovascular diseases by reducing pathophysiology derived from HCD-mediated endothelial dysfunction.

The hexane fraction of Naematoloma sublateritium extract suppresses the TNF-α-induced metastatic potential of MDA-MB-231 breast cancer cells through modulation of the JNK and p38 pathways.

Naematoloma sublateritium (Fr.) P. Karst is a basidiomycete that has been used as traditional medicine. N. sublateritium produces a triterpenoid antitumor compound, clavaric acid, but, in general, the effects of N. sublateritium constituents against tumor invasion and metastasis have been poorly studied. To investigate the inhibitory effect of N. sublateritium constituents on highly invasive and metastatic tumor cells, the TNF-α-stimulated human breast cancer cell line, MDA-MB­231 was treated with the hexane fraction of an N. sublateritium extract (HFNS). Non-cytotoxic concentrations of HFNS markedly inhibited the invasion and migration of the MDA-MB­231 cells in the Matrigel invasion assay and wound-healing analysis, respectively. Gelatin zymography showed that HFNS suppressed the activity of MMP-9, but not of MMP-2. Immunoblotting demonstrated that treatment with HFNS had decreased the level of MMP-9 and urokinase plasminogen activator-1 (uPA-1), but had upregulated expression of the endogenous inhibitor proteins, including TIMP-1,-2, and PAI-1, in a dose-dependent manner. Furthermore, HFNS suppressed the phosphorylation of p38 and JNK1/2, but not that of ERK1/2. This was confirmed by pretreatment of cells with specific inhibitors prior to stimulation with TNF-α. HFNS treatment also led to a dose-dependent inhibition of the DNA-binding activities of AP-1 and NFκB, which are downstream targets of JNK and p38. These data suggested that HFNS inhibits the metastatic potential of MDA-MB­231 cells by inhibiting the phosphorylation of JNK/p38 and reducing AP-1 and NFκB DNA-binding activities. Therefore, HFNS may be a potential therapeutic agent against metastasis of breast cancer.

A standardized bamboo leaf extract inhibits monocyte adhesion to endothelial cells by modulating vascular cell adhesion protein-1.

Bamboo leaves (Phyllostachys pubescens Mazel ex J. Houz (Poacea)) have a long history of food and medical applications in Asia, including Japan and Korea. They have been used as a traditional medicine for centuries. We investigated the mechanism of anti-inflammatory activity of a bamboo leaf extract (BLE) on tumor necrosis factor-alpha (TNF-α)-induced monocyte adhesion in human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs to BLE did not inhibit cell viability or cause morphological changes at concentrations ranging from 1 µg/ml to 1 mg/ml. Treatment with 0.1 mg/ml BLE caused 63% inhibition of monocyte adhesion in TNF-α-activated HUVECs, which was associated with 38.4% suppression of vascular cell adhesion molecule-1 expression. Furthermore, TNF-α-induced reactive oxygen species generation was decreased to 47.9% in BLE treated TNF-α-activated HUVECs. BLE (0.05 mg/ml) also caused about 50% inhibition of interleukin-6 secretion from lipopolysaccharide-stimulated monocyte. The results indicate that BLE may be clinically useful as an anti-inflammatory or anti-oxidant for human cardiovascular disease including atherosclerosis.

Cordycepin-induced apoptosis and autophagy in breast cancer cells are independent of the estrogen receptor.

Cordycepin (3-deoxyadenosine), found in Cordyceps spp., has been known to have many therapeutic effects including immunomodulatory, anti-inflammatory, antimicrobial, and anti-aging effects. Moreover, anti-tumor and anti-metastatic effects of cordycepin have been reported, but the mechanism causing cancer cell death is poorly characterized. The present study was designed to investigate whether the mechanisms of cordycepin-induced cell death were associated with estrogen receptor in breast cancer cells. Exposure of both MDA-MB-231 and MCF-7 human breast cancer cells to cordycepin resulted in dose-responsive inhibition of cell growth and reduction in cell viability. The cordycepin-induced cell death in MDA-MB-231 cells was associated with several specific features of the mitochondria-mediated apoptotic pathway, which was confirmed by DNA fragmentation, TUNEL, and biochemical assays. Cordycepin also caused a dose-dependent increase in mitochondrial translocation of Bax, triggering cytosolic release of cytochrome c and activation of caspases-9 and -3. Interestingly, MCF-7 cells showed autophagy-associated cell death, as observed by the detection of an autophagosome-specific protein and large membranous vacuole ultrastructure morphology in the cytoplasm. Cordycepin-induced autophagic cell death has applications in treating MCF-7 cells with apoptotic defects, irrespective of the ER response. Although autophagy has a survival function in tumorigenesis of some cancer cells, autophagy may be important for cordycepin-induced MCF-7 cell death. In conclusion, the results of our study demonstrate that cordycepin effectively kills MDA-MB-231 and MCF-7 human breast cancer cell lines in culture. Hence, further studies should be conducted to determine whether cordycepin will be a clinically useful, ER-independent, chemotherapeutic agent for human breast cancer.

Arginase Inhibition by Ethylacetate Extract of Caesalpinia sappan Lignum Contributes to Activation of Endothelial Nitric Oxide Synthase.

Caesalpinia sappan (C. sappan) is a medicinal plant used for promoting blood circulation and removing stasis. During a screening procedure on medicinal plants, the ethylacetate extract of the lignum of C. sappan (CLE) showed inhibitory activity on arginase which has recently been reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. CLE inhibited arginase II activity prepared from kidney lysate in a dose-dependent manner. In HUVECs, inhibition of arginase activity by CLE reciprocally increased NOx production through enhancement of eNOS dimer stability without any significant changes in the protein levels of eNOS and arginase II expression. Furthermore, CLE-dependent arginase inhibition resulted in increase of NO generation and decrease of superoxide production on endothelium of isolated mice aorta. These results indicate that CLE augments NO production on endothelium through inhibition of arginase activity, and may imply their usefulness for the treatment of cardiovascular diseases associated with endothelial dysfunction.

Vasorelaxing Activity of Ulmus davidiana Ethanol Extracts in Rats: Activation of Endothelial Nitric Oxide Synthase.

Ulmus davidiana var. japonica Rehder (Urticales: Ulmaceae) (UD) is a tree widespread in northeast Asia. It is traditionally used for anticancer and anti-inflammatory therapy. The present study investigated the effect of an ethanol extract of UD on vascular tension and its underlying mechanism in rats. The dried root bark of UD was ground and extracted with 80% ethanol. The prepared UD extract was used in further analysis. The effect of UD on the cell viability, vasoreactivity and hemodynamics were investigated using propidium iodide staining in cultured cells, isometric tension recording and blood pressure analysis, respectively. Low dose of UD (10~100µg/ml) did not affect endothelial cell viability, but high dose of UD reduced cell viability. UD induced vasorelaxation in the range of 0.1~10µg/ml with an ED(50) value of 2µg/ml. UD-induced vasorelaxation was completely abolished by removal of the endothelium or by pre-treatment with L-NAME, an inhibitor of nitric oxide synthase. UD inhibited calcium influx induced by phenylephrine and high K(+) and also completely abolished the effect of L-NAME. Intravenous injection of UD extracts (10~100 mg/kg) decreased arterial and ventricular pressure in a dose-dependent manner. Moreover, UD extracts reduced the ventricular contractility (+dP/dt) in anesthetized rats. However, UD-induced hypotensive actions were minimized in L-NAME-treated rats. Taken together, out results showed that UD induced vasorelaxation and has antihypertensive properties, which may be due the activation of nitric oxide synthase in endothelium.

Modulating effect of ginseng saponins on heterologously expressed HERG currents in Xenopus oocytes.

AIM: To examine the effects of ginseng saponins on the heterologously expressed human ether-a-go-go related gene (HERG) that encodes the rapid component of the delayed rectifier K+ channel. METHODS: A two-electrode voltage clamp technique was used. HERG currents were recorded in Xenopus oocytes injected with HERG cRNA. RESULTS: Crude saponins of Korean red ginseng (GS) induced a minimal increase of the maximal HERG conductance without changes in the voltage-dependent HERG current activation and inactivation curves. GS, however, decelerated HERG current deactivation in a concentration-dependent manner, which was more noticeable with panaxitriol (PT) than panaxidiol (PD). Consistently, ginseng saponins increased the HERG deactivation time constants with the order of potency of Rg1 (a major component of PT)>Rf1>Rb1 (a major component of PD). Re had little effect on HERG deactivation. During a cardiac action potential, GS increased the outward HERG current. CONCLUSION: Ginseng saponins enhance HERG currents, which could be in part a possible mechanism of the shortening cardiac action potential of ginseng saponins.

Effect of Korea red ginseng on cerebral blood flow and superoxide production.

AIM: To investigate the effects of Korea red ginseng (KRG) on the cerebral perfusion rate in the rats and the generation of superoxide anion in the endothelial cells. METHODS: The cerebral perfusion rate was measured using laser-doppler flowmetry before and after the administration of crude saponin (CS) and saponin-free fraction (SFF) of KRG in the anesthetized rats. The superoxide generation was measured by the method based on lucigenin-enhanced chemiluminescence in the cultured endothelial cells. RESULTS: The relative cerebral perfusion rate (rCBF) was significantly increased by the intraperitoneal injection of CS (100 mg/kg) in the rats, but SFF had no effect on the rCBF. Chronic treatment with CS for 7 d significantly inhibited the decrease of forebrain cerebral blood flow induced by clamping both carotid arteries in the rats. Furthermore, CS (0.1 g/L) significantly suppressed NADPH-induced superoxide generation in the human umbilical vein endothelial cells (P <0.01). CONCLUSION: The present study demonstrated that crude saponin fraction of KRG enhanced cerebral blood flow in rats. Furthermore, crude saponin fraction of KRG abrogated the NADPH-driven superoxide generation in endothelial cells.