Min-Ja Lee

Curcumin inhibits TNFα-induced lectin-like oxidised LDL receptor-1 (LOX-1) expression and suppresses the inflammatory response in human umbilical vein endothelial cells (HUVECs) by an antioxidant mechanism

In this study, the anti-oxidative activities of 70% ethanol extract from Curcuma aromatica Salisb. (CAS) and curcumin (CUR) were studied. The CAS extracts and CUR were both found to have a potent scavenging activity against the reactive species tested, as well as an inhibitory effect on LDL oxidation. Cultured human umbilical vein endothelial cells (HUVECs) were stimulated with tumour necrosis factor α (TNFα), expression of intracellular reactive oxygen species (ROS), nitric oxide (NO), endothelial nitric oxide synthase (eNOS), lectin-like oxidised LDL receptor-1 (LOX-1), adhesion molecules, inhibitory kappa Bα (IκBα) and nuclear factor kappa B (NFκB) were measured. In HUVECs stimulated with TNFα, CUR significantly suppressed expression of the intracellular ROS, LOX-1 and adhesion molecules, degradation of IκBα and translocation of NFκB, while inducing production of NO by phosphorylation of eNOS (p <0.05). In conclusion, CAS and CUR may modulate lipoprotein composition and attenuate oxidative stress by elevated antioxidant processes.

Genistein Suppresses Tumor Necrosis Factor-α-Induced Proliferation via the Apoptotic Signaling Pathway in Human Aortic Smooth Muscle Cells

The proliferation of vascular smooth muscle cells (VSMCs) plays a key role in the development of atherosclerosis. Abnormal VSMC proliferation induces vascular dysfunction and several other pathological processes. The present study investigated the apoptotic effects of genistein on tumor necrosis factor-alpha (TNF-alpha)-induced proliferation in human aortic smooth muscle cells (HASMCs). The apoptotic effects of genistein were assessed to determine the mechanism(s) of its antiproliferative activity, including MTT, LDH assay, morphological change of cell, DNA fragmentation, and expression levels of pro- or anti-apoptotic molecules by RT-PCR and Western blots. The results show that genistein significantly reduced cell proliferation in TNF-alpha-induced HASMCs. Genistein also reduced intracellular nuclei staining with DAPI in a dose-dependent manner. In addition, genistein increased nucleosomal DNA fragmentation, increased the expression levels of Bax and c-Myc, and decreased the expression levels of Bcl-2 and Bcl-xL in TNF-alpha-induced HASMCs. Taken together, these findings indicate that genistein regulates the activation of apoptosis-related molecules in TNF-alpha-induced HASMCs, leading to the suppression of proliferation and induction of apoptosis.

Effect of bamboo culm extract on oxidative stress and genetic expression: Bamboo culm extract ameliorates cell adhesion molecule expression and NFκB activity through the suppression of the oxidative stress

BACKGROUND & AIMS This study was designed to investigate whether bamboo culm extract (BCE) supplementation may ameliorate risk factors of cardiovascular diseases, such as hypercholesterolemia. METHODS Oxidative stress and inflammatory mediators in plasma, livers of C57BL/6 mice fed high-cholesterol diet and calf pulmonary artery endothelial (CPAE) cells. Briefly, C57BL/6 mice were fed the high-cholesterol diet which was supplemented with 1% (w/w), or 3% (w/w) of BCE for 16 weeks. The concentration of total cholesterol, LDL-cholesterol, HDL-cholesterol level and atherogenic index were measured. Plasma TEAC value, hepatic thiobarbituric acid reactive substances (TBARS), protein carbonyl values and hepatic antioxidant enzyme activities, such as Cu,Zn-superoxide dismutase (SOD), Mn-SOD, glutathione peroxidase (GSH-Px), GSH reductase and catalase were determined. In addition, hepatic nuclear factor kappa B activities were detected. In the calf pulmonary artery endothelial (CPAE) cells stimulated with lipopolysaccharide, the expression of vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1) were measured. RESULTS Plasma cholesterol level was decreased, while HDL-cholesterol was increased, thus atherogenic index was lowered in BCE-supplemented animals. Plasma trolox equivalent and hepatic thiobarbituric acid reactive substances and protein carbonyl values were lowered significantly in BCE groups (p<0.05) in a dose-dependent manner. Hepatic antioxidative enzyme activities, such as Cu,Zn-superoxide dismutase (SOD), Mn-SOD, glutathione peroxidase (GSH-P), GSH reductase, and catalase were elevated in mice fed BCE-supplemented diets (p<0.05). Nuclear factor kappa B activities of livers and vascular cell adhesion molecule-1 and intracellular cell adhesion molecule-1 expressions in CPAE cells stimulated with lipopolysaccharide were significantly lowered in BCE groups (p<0.05). CONCLUSION These results suggest that BCE supplementation may modulate lipoprotein composition and attenuate oxidative stress by elevated antioxidative processes, thus suppressing inflammatory mediator activation as possible mechanism of its anti-atherogenic effect.

Leonurus sibiricus Herb Extract Suppresses Oxidative Stress and Ameliorates Hypercholesterolemia in C57BL/6 Mice and TNF-α Induced Expression of Adhesion Molecules and Lectin-Like Oxidized LDL Receptor-1 in Human Umbilical Vein Endothelial Cells

In Leonurus sibiricus herb extract (LHE)-supplemented animals, plasma cholesterol decreased and high-density lipoprotein-cholesterol increased, resulting in a lowered atherogenic index. The plasma trolox equivalent antioxidant capacity, levels of hepatic thiobarbituric acid-reactive substances, and protein carbonyl values decreased significantly in LHE-supplemented mice (p<0.05), whereas the hepatic antioxidant indicators were all significantly elevated (p<0.05). In human umbilical vein endothelial cells stimulated with tumor necrosis factor alpha, LHE significantly suppressed intracellular reactive oxygen species, LOX-1, and adhesion molecules. LHE supplementation may modulate the lipoprotein composition and attenuate oxidative stress by elevated antioxidant processes, thus suppressing the activation of inflammatory mediators. This is a possible mechanism of the anti-atherogenic effect.

Caesalpinia sappan L. ameliorates hypercholesterolemia in C57BL/6 mice and suppresses inflammatory responses in human umbilical vein endothelial cells (HUVECs) by antioxidant mechanism.

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Protective effects of luteolin-7-O-β-D-glucuronide methyl ester from the ethyl acetate fraction of Lycopi Herba against pro-oxidant reactive species and low-density lipoprotein peroxidation

In this study the potent scavenging activity of “Lycopi Herba” (LH) extract was studied using the following: evaluation of the total phenolics, measuring the antioxidant activity by Trolox equivalent antioxidant concentration, measuring the scavenging effects on reactive oxygen species, on reactive nitrogen species, and measuring the inhibitory effect on Cu2+ induced human low-density lipoprotein oxidation in vitro. The ethyl acetate fraction from the LH extracts were found to have a potent scavenging activity against all of the reactive species tested, as well as an inhibitory effect on LDL oxidation. Therefore, we isolated and identified luteolin-7-O-β-D-glucuronide methyl ester as the major compound from the ethyl acetate fraction of LH and their antioxidant activities were evaluated.

RETRACTED: Antioxidant properties of benzylchroman derivatives from Caesalpinia sappan L. against oxidative stress evaluated in vitro

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Bamboo Culm Extract Supplementation Elevates HDL-Cholesterol and Ameliorates Oxidative Stress in C57BL/6 Mice Fed Atherogenic Diet

Previously, we reported that bamboo culms possess a stronger antioxidative capacity than bamboo leaves in vitro. In this study, we investigated whether bamboo culm extract (BCE) supplementation ameliorates oxidative stress and hepatic nuclear factor kappaB (NF kappa B) activation in C57BL/6 mice fed an atherogenic diet. In addition, the effect of BCE supplementation on plasma lipid levels of the animals was tested. The mice were randomly assigned to a normal diet, an atherogenic diet (control), or an atherogenic diet supplemented with 1% (wt/wt) BCE or 3% (wt/wt) BCE for 16 weeks. Atherogenic diet-induced oxidative stress, measured by hepatic thiobarbituric acid-reactive substances and protein carbonyls, was significantly lower in the BCE-supplemented groups than in the control (P < .05). Total antioxidative capacity was elevated in the BCE groups, along with greater activities of antioxidative enzymes such as superoxide dismutase and catalase, compared to the control or normal groups (P < .05). The hepatic NF kappa B binding activities were significantly lower in the BCE groups as well (P < .05). The high-density lipoprotein-cholesterol level was significantly elevated by BCE supplementation (P < .05), whereas the effects of BCE on triglyceride and total cholesterol were inconsistent. Results from this study suggest that BCE supplementation may lessen oxidative stress via a series of changes, including a reinforced antioxidant system, and also suggest that the lowered oxidative stress status may down-regulate the activation of inflammatory mediators.