1-1-diphenyl-2-picrylhydrazyl and Atherosclerosis

Myeloperoxidase (MPO) is known to cause oxidative stress and inflammation leading to cardiovascular disease (CVD) complications. MPO-mediated oxidation of lipoproteins leads to dysfunctional entities altering the landscape of lipoprotein functionality. The specificity of guaiacol derivatives toward preventing MPO-mediated oxidation to limit MPO's harmful effects is unknown. Diligent in silico studies were accomplished for a portfolio of compounds with guaiacol as a building block. The compounds' activity toward MPO inhibition was also validated. The role of these chemical entities in controlling MPO-mediated oxidation of lipoproteins (LDL and HDL) was shown to agree with our approach of developing powerful MPO inhibitors. The mechanism of MPO inhibition was demonstrated to be reversible in nature. This study reveals that there is great potential for guaiacol derivatives as therapeutics for CVD by modulating lipid profiles, reducing atherosclerotic plaque burden, and subsequently optimizing cardiovascular functions.

Topics: Animals; Antioxidants; Atherosclerosis; Benzothiazoles; Biphenyl Compounds; Cardiovascular Diseases; Cell Survival; Cells, Cultured; Dose-Response Relationship, Drug; Enzyme Inhibitors; Guaiacol; Humans; Interleukin-1beta; Lipopolysaccharides; Mice; Molecular Docking Simulation; Molecular Structure; Peroxidase; Picrates; RAW 264.7 Cells; Structure-Activity Relationship; Sulfonic Acids; Tumor Necrosis Factor-alpha

Pathogenesis of atherosclerosis involves vascular smooth muscle cell (VSMC) migration and proliferation followed by an inflammation mediated by activated macrophages in the tunica intima of blood vessels. Cepharanthine (CEP) belongs to bisbenzylisoquinoline alkaloids found in the plant Stephania cepharantha, which has been used for various diseases like cancer, alopecia areata, venomous snakebites, and malaria. In this study, we investigated whether CEP suppresses VSMC migration and proliferation and inhibits inflammatory mediator production in macrophage (RAW264.7). Our results showed that CEP possessed significant DPPH scavenging and metal chelating activities. It also markedly inhibited lipid peroxidation. Similarly, CEP suppressed the nitric oxide (NO) production and expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) in RAW264.7 cells. Moreover, the level of prostaglandin E2 was also suppressed and the formation of macrophage derived foam cell was attenuated in RAW264.7 cells. Likewise, NO production in isolated peritoneal macrophage and VSMC migration in response to LPS stimulated RAW264.7 was also halted by CEP treatment. Also, VSMC migration induced by platelet-derived growth factor (PDGF-BB) was inhibited by CEP dose dependently. The anti-migratory effect of CEP on VSMCs was due to its inhibitory effect on metalloproteinase-9 (MMP-9) expression, preventing the degradation of extracellular matrix (ECM) component. Furthermore, CEP suppressed PDGF-BB induced VSMC proliferation by down-regulation of mitogen activated protein kinase (MAPK) signaling molecules. CEP also inhibited the translocation of NF-κB from cytosol to nucleus. Thus, our results suggest that CEP exerts potent anti-atherosclerotic effect through attenuation of inflammation, lipid peroxidation and VSMC migration and proliferation.

Topics: Animals; Anti-Inflammatory Agents; Atherosclerosis; Becaplermin; Benzylisoquinolines; Biphenyl Compounds; Cell Movement; Cell Proliferation; Cells, Cultured; Cyclooxygenase 2; Dinoprostone; Humans; Iron; Lipid Peroxidation; Mice; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nitric Oxide; Nitric Oxide Synthase Type II; Picrates; Proto-Oncogene Proteins c-sis; RAW 264.7 Cells

The antioxidant activities of ethyl acetate extraction of purple rice (EAEPR) were evaluated by various methods in vitro and in vivo. In in vitro antioxidant assays, EAEPR was found to have strong 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity hydroxyl radical, reducing power and metal-ion chelating activity. In in vivo antioxidant assays, mice were administered with EAEPR via gavage for 42 consecutive days. As a result, administration of EAEPR significantly enhanced the activities of glutathione peroxidase in serums and livers of mice. EAEPR could improve the lipid status, especially total cholesterol and low-density lipoprotein cholesterol levels. In addition, total phenolic content of EAEPR was 188.21mg/g. The main phenolic compounds in EAEPR analyzed by ultra-high performance liquid chromatography tandem mass spectrometry were determined as ferulic acid and quercetin. The contents of ferulic acid and quercetin in EAEPR were 14.21mg/g and 35.28mg/g, respectively. The Nrf2 expression was significantly elevated after administration of EAEPR.These results suggested that EAEPR had potent antioxidant activity and could be explored as a novel natural antioxidant.

Topics: Acetates; Animals; Antioxidants; Atherosclerosis; Biphenyl Compounds; Chelating Agents; Diet; Fatty Liver; Free Radical Scavengers; Gene Expression Regulation; Iron; Lipids; Liver; Male; Mice; Oryza; Oxidation-Reduction; Phenols; Picrates; Real-Time Polymerase Chain Reaction

Hwangryunhaedok-tang (HHT) is a traditional herbal medicine that is used for the treatment of fever, inflammation, gastritis, and hypertension. In this study, we performed simultaneous determination of the five components, geniposide (1), baicalin (2), coptisine (3), palmatine (4), and berberine (5) in HHT by using a high-performance liquid chromatography-photodiode array (HPLC-PDA) analysis. We also evaluated the antioxidative activity of HHT and compounds 1-5 by measuring their effects on low-density lipoprotein (LDL) oxidation and antiproliferative abilities in vascular smooth muscle cells (VSMCs).. Five compounds were separated within 40 min by using a Gemini C18 column (temp. 35°C; two-component gradient elution; flow rate 1.0 mL/min; detector 240 and 277 nm). The activities of HHT and compounds 1-5 were tested with the radical scavengers 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and 2,2-diphenyl-1-picrylhydrazyl, in thiobarbituric acid reactive substance assays, and in relative electrophoretic mobility assays using CuSO4-induced LDL oxidation systems. The antiproliferative effects of samples on platelet-derived growth factor (PDGF)-induced VSMC proliferation were studied by using a cell proliferation assay.. Regression analysis of the five major compounds showed good linearity (r (2) ≥ 0.9997) in different concentration ranges. The recoveries of the five compounds were in the range 86.31-110.78%, with relative standard deviations below 2.1%; those of intra- and interday precision were 0.04-3.78% and 0.04-1.69%, respectively. HHT reduced the oxidation properties of LDL induced by CuSO4 and inhibited cell proliferation in PDGF-treated VSMCs. Among the five components, compound 2 could effectively suppress LDL oxidation and PDGF-induced VSMC proliferation.. The established HPLC-PDA method will help to improve quality control of HHT. The results demonstrate that HHT has antiatherosclerotic activity and that it functions by modulating LDL oxidation and VSMC proliferation. The effects of HHT may be attributed, at least I part, to compound 2.

Topics: Animals; Antioxidants; Atherosclerosis; Berberine; Berberine Alkaloids; Biphenyl Compounds; Cell Proliferation; Chromatography, High Pressure Liquid; Coptis; Drugs, Chinese Herbal; Flavonoids; Gardenia; Iridoids; Lipoproteins, LDL; Medicine, Korean Traditional; Muscle, Smooth, Vascular; Phellodendron; Phytotherapy; Picrates; Platelet-Derived Growth Factor; Rats; Regression Analysis; Scutellaria

Because atherosclerosis is an inflammatory process involving a series of pathological events such as dyslipidemia, oxidative stress, and blood clotting mechanisms, we hereby report the synthesis and evaluation of novel compounds in which antioxidant, anti-inflammatory, and squalene synthase (SQS) inhibitory/hypolipidemic activities are combined in simple molecules through design. The coupling of two different pharmacophores afforded compounds 1-12, whose biological profile was markedly improved compared to those of parent lead structures (i.e., the hypolipidemic 2-hydroxy-2-aryl-(benzo)oxa(or thia)zine and the antioxidant phenothiazine). Most derivatives strongly inhibited in vitro microsomal lipid and LDL peroxidation, exhibiting potent free-radical scavenging activity. They further significantly inhibited SQS activity and showed remarkable antidyslipidemic activity in vivo in animal models of acute and high-fat-induced hyperlipidemia. Finally, several compounds showed anti-inflammatory activity in vitro, inhibiting cycloxygenase (COX-1/2) activity. The multimodal properties of the new compounds and especially their combined antioxidant/SQS/COX inhibitory activity render them interesting lead compounds for further evaluation against atherosclerosis.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Atherosclerosis; Biphenyl Compounds; Carrageenan; Cholesterol, Dietary; Cyclooxygenase Inhibitors; Diet, High-Fat; Drug Design; Edema; Enzyme Inhibitors; Farnesyl-Diphosphate Farnesyltransferase; Hypolipidemic Agents; In Vitro Techniques; Indicators and Reagents; Lipid Peroxidation; Magnetic Resonance Spectroscopy; Male; Mice; Microsomes; Phenothiazines; Picrates; Rats

Gossypetin, a flavone originally isolated from Hibiscus species, has been shown to possess antioxidant, antimicrobial, and antimutagenic activities. Here, we investigated the mechanism(s) underlying the anti-atherosclerotic potential of gossypetin. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay showed that the addition of >50μM of gossypetin could scavenge over 50% of DPPH radicals. The inhibitory effects of gossypetin on the lipid and protein oxidation of LDL were defined by thiobarbituric acid reactive substance (TBARS) assay, the relative electrophoretic mobility (REM) of oxidized LDL (ox-LDL), and fragmentation of apoB in the Cu(2+)-induced oxidation of LDL. Gossypetin showed potential in reducing ox-LDL-induced foam cell formation and intracellular lipid accumulation, and uptake ability of macrophages under non-cytotoxic concentrations. Molecular data showed that these influences of gossypetin might be mediated via peroxisome proliferator-activated receptor α (PPARα)/liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) and PPARγ/scavenger receptor CD36 pathways, as demonstrated by the transfection of PPARα siRNA or PPARγ expression vector. Our data implied that gossypetin regulated the PPAR signals, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that gossypetin potentially could be developed as an anti-atherosclerotic agent.

Topics: Animals; Atherosclerosis; Biphenyl Compounds; Cell Culture Techniques; Cell Line; Cell Survival; Electrophoretic Mobility Shift Assay; Flavonoids; Foam Cells; Free Radical Scavengers; Humans; Lipid Peroxidation; Lipoproteins, LDL; Mice; Picrates; Thiobarbituric Acid Reactive Substances

It is well known that extracts of purple sweet potato (PSP) have potent antioxidant activity. However, it has not been established whether extracts of PSP inhibit oxidation of low-density lipoprotein (LDL) or protein glycation. LDL oxidation and protein glycation are well-known risk factors for chronic metabolic diseases, such as atherosclerosis and diabetes mellitus. Chopped and sliced PSP and yellow sweet potato (YSP) were extracted individually at a concentration of 1 g of PSP tuber/mL using either ethanol or water for 6 hours. The PSP ethanol extract (100-fold diluted) showed stronger radical (2,2-diphenyl-1-picrylhydrazyl radical) scavenging activity than the water extract of PSP and the ethanol extract of YSP (up to a sixfold higher activity). The ethanol extract of PSP also exhibited the highest increase in ferric reducing ability among all extracts. Cupric ion-mediated LDL oxidation was strongly inhibited by the ethanol extract of PSP, with similar potency to vitamin C treatment (final concentration, 10 mM). The PSP extract strongly inhibited fructose-mediated protein glycation as determined by fluorescence spectroscopy. The PSP extract-treated apolipoprotein (apo) A-I showed a decreased multimerization pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whereas glycated apoA-I showed the strongest multimeric band. PSP extract treatment also inhibited the uptake of oxidized LDL into human macrophage cells with suppression of malondialdehyde production in the cell culture medium. In conclusion, these results suggest that the extract of PSP can be used as a putative anti-atherosclerotic and antidiabetic agent with strong antioxidant functions. This is the first report to show the biological functions of PSP extract to treat hyperlipidemic and hyperglycemic disorders.

Topics: Antioxidants; Apolipoprotein A-I; Ascorbic Acid; Atherosclerosis; Biphenyl Compounds; Cholesterol, LDL; Fructose; Glycation End Products, Advanced; Glycosylation; Humans; Ipomoea batatas; Lipid Peroxidation; Macrophages; Malondialdehyde; Phytotherapy; Picrates; Plant Extracts; Plant Roots

Low-density lipoprotein (LDL) oxidation plays a role in atherosclerosis; therefore the lower the formation of oxidative LDL (oxLDL), the lower the occurrence of coronary heart diseases (CHD). Mulberry, the fruit of Morus alba L., is used effectively in Chinese medicines for prevention of CHD. However, the mechanism of this action is unclear. Two extracts, MWEs (mulberry water extracts) and MACs (mulberry anthocyanin-rich extracts), which exhibit antioxidative and anti-atherosclerogensis abilities in vitro. Data showed that MWEs and MACs were able to inhibit (P<0.05) the relative electrophoretic mobility (REM), ApoB fragmentation, and thiobarbituric acid reaction substances (TBARS) formation in Cu2+ -mediated oxidation LDL. MWEs and MACs also had the ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging for reducing the formation of free radicals mediated by copper ions. Furthermore, we observed that MWEs and MACs could decrease (P<0.05) macrophage death induced by oxLDL. In addition, the MWEs and MACs also could inhibit (P<0.05) the formation of foam cells. Both MWEs and MACs showed a great ability of scavenging radicals, inhibition of LDL oxidation, and decrease in atherogenic stimuli in macrophages, while the efficacy of MACs is 10-fold greater than that of MWEs. It also demonstrated that anthocyanin components in mulberry extracts were regarded as the prevention of atherosclerosis.

Topics: Anthocyanins; Atherosclerosis; Biphenyl Compounds; Copper; Foam Cells; Free Radical Scavengers; Fruit; Humans; Lipoproteins, LDL; Macrophages; Morus; Oxidation-Reduction; Picrates; Plant Extracts; Thiobarbituric Acid Reactive Substances

The properties of Mon Thong, Chani and Kan Yao durian (Durio zibethinus Murr.) cultivars were compared in vitro and in vivo studies in order to find the best one as a supplement to antiatherosclerotic diet. Total polyphenols (361.4+/-35.3 mgGAE/100g FW), flavonoids (93.9+/-8.9 mgCE/100g FW) and total antioxidant capacity determined by DPPH and beta-carotene-linoleic acid assays (261.3+/-25.3 microMTE/100g FW and 77.8+/-7.8% of inhibition) were maximal in Mon Thong in comparison with Chani and Kan Yao and showed a good correlation between these three variables (R(2)=0.9859). Five groups of rats were fed diets supplemented with cholesterol and different durian cultivars. Diets supplemented with Mon Thong and to a lesser degree with Chani and Kan Yao significantly hindered the rise in the plasma lipids (TC - 8.7%, 16.1% and 10.3% and (b) LDL-C - 20.1%, 31.3% and 23.5% for the Chol/Kan Yao, Chol/Mon Thong and Chol/Chani, respectively) and the decrease in plasma antioxidant activity (P<0.05). Nitrogen retention remained significantly higher in Chol/Mon Thong than in other diet groups. Diet supplemented with Mon Thong affected the composition of plasma fibrinogen in rats and showed more intensity in protein bands around 47 kDa. No lesions were found in the examined tissue of heart and brains. Mon Thong cultivar is preferable for the supplementation of the diet as positively influenced the lipid, antioxidant, protein and metabolic status. The durian fruit till now was not investigated extensively, therefore based on the results of this study durian cultivars can be used as a relatively new source of antioxidants.

Topics: Animals; Antioxidants; Atherosclerosis; beta Carotene; Biphenyl Compounds; Bombacaceae; Cholesterol, Dietary; Dietary Supplements; Flavonoids; Fruit; Hydrazines; Lipids; Male; Phenols; Phytotherapy; Picrates; Plant Preparations; Polyphenols; Rats; Rats, Wistar

Moringa oleifera is used in Thai traditional medicine as cardiotonic. Recent studies demonstrated its hypocholesterolaemic effect. However, to be clinically useful, more scientific data are needed.. We investigated the antioxidant, hypolipidaemic and antiatherosclerotic activities of Moringa oleifera leaf extract.. Scavenging activity of the extract on 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), and the inhibitory effect on Cu(2+)-induced low-density lipoprotein (LDL) oxidation were determined in in vitro experiment. The effects of the extract on cholesterol levels, conjugated diene (CD) and thiobarbituric acid reactive substances (TBARS) and plaque formations in cholesterol-fed rabbits were investigated.. We found that in scavenging DPPH radicals the extract and Trolox had IC(50) of 78.15+/-0.92 and 2.14+/-0.12microg/ml, respectively. The extract significantly (P<0.05) prolonged the lag-time of CD formation and inhibited TBARS formation in both in vitro and ex vivo experiments in a dose-dependent manner. In hypercholesterol-fed rabbits, at 12 weeks of treatment, it significantly (P<0.05) lowered the cholesterol levels and reduced the atherosclerotic plaque formation to about 50 and 86%, respectively. These effects were at degrees comparable to those of simvastatin.. The results indicate that this plant possesses antioxidant, hypolipidaemic and antiatherosclerotic activities and has therapeutic potential for the prevention of cardiovascular diseases.

Topics: Animals; Antioxidants; Atherosclerosis; Biphenyl Compounds; Body Weight; Cholesterol; Cholesterol, Dietary; Humans; Hypolipidemic Agents; Lipids; Lipoproteins, LDL; Male; Moringa oleifera; Picrates; Plant Extracts; Plant Leaves; Rabbits; Simvastatin; Thiobarbituric Acid Reactive Substances; Vitamin E; Water

Atherosclerosis is a chronic inflammatory disease of the arterial wall. Kaempferol and rhamnocitrin (kaempferol 7-O-methyl ether) are two anti-inflammatory flavonoids commonly found in plants. The aim of this study is to investigate the function of kaempferol and rhamnocitrin on prevention of atherosclerosis. Chemical analyses demonstrated that kaempferol and rhamnocitrin were scavengers of DPPH (1,1-diphenyl-2-picrylhydrazyl) with IC50 of 26.10 +/- 1.33 and 28.38 +/- 3.07 microM, respectively. Copper-induced low-density lipoprotein (LDL) oxidation was inhibited by kaempferol and rhamnocitrin, with similar potency, as measured by decreased formation of malondialdehyde and relative electrophoretic mobility (REM) on agarose gel, while rhamnocitrin reduced delayed formation of conjugated dienes better than kaempferol. Cholesterol-laden macrophages are the hallmark of atherogenesis. The class B scavenger receptor, CD36, binds oxidized low-density lipoprotein (oxLDL), is found in atherosclerotic lesions, and is up-regulated by oxLDL. Addition of kaempferol and rhamnocitrin (20 microM) caused significant reductions in cell surface CD36 protein expression in THP-1-derived macrophages (p < 0.05). Reverse transcription quantitative PCR (RT-Q-PCR) showed that kaempferol and rhamnocitrin (20 microM) decreased oxLDL-induced CD36 mRNA expression (p < 0.01 and p < 0.05, respectively). Kaempferol- and rhamnocitrin-treated macrophages also showed reduction in 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanide perchlorate (DiI)-labeled oxLDL uptake. Current evidences indicate that kaempferol and rhamnocitrin not only protect LDL from oxidation but also prevent atherogenesis through suppressing macrophage uptake of oxLDL.

Topics: Anti-Inflammatory Agents; Atherosclerosis; Biphenyl Compounds; CD36 Antigens; Dose-Response Relationship, Drug; Flavonoids; Gene Expression; Humans; Inhibitory Concentration 50; Kaempferols; Lipid Peroxidation; Lipoproteins, LDL; Macrophages; Oxidation-Reduction; Picrates; RNA, Messenger

The oxidative modification of LDL may play an important role in the early events of atherogenesis. Thus the identification of antioxidative compounds may be of therapeutic and prophylactic importance regarding cardiovascular disease. Copper-chlorophyllin (Cu-CHL), a Cu(2+)-protoporphyrin IX complex, has been reported to inhibit lipid oxidation in biological membranes and liposomes. Hemin (Fe(3+)-protoporphyrin IX) has been shown to bind to LDL thereby inducing lipid peroxidation. As Cu-CHL has a similar structure as hemin, one may assume that Cu-CHL may compete with the hemin action on LDL. Therefore, in the present study Cu-CHL and the related compound magnesium-chlorophyllin (Mg-CHL) were examined in their ability to inhibit LDL oxidation initiated by hemin and other LDL oxidizing systems. LDL oxidation by hemin in presence of H(2)O(2) was strongly inhibited by both CHLs. Both chlorophyllins were also capable of effectively inhibiting LDL oxidation initiated by transition metal ions (Cu(2+)), human umbilical vein endothelial cells (HUVEC) and tyrosyl radicals generated by myeloperoxidase (MPO) in presence of H(2)O(2) and tyrosine. Cu- and Mg-CHL showed radical scavenging ability as demonstrated by the diphenylpicrylhydracylradical (DPPH)-radical assay and estimation of phenoxyl radical generated diphenyl (dityrosine) formation. As assessed by ultracentrifugation the chlorophyllins were found to bind to LDL (and HDL) in serum. The present study shows that copper chlorophyllin (Cu-CHL) and its magnesium analog could act as potent antagonists of atherogenic LDL modification induced by various oxidative stimuli. As inhibitory effects of the CHLs were found at concentrations as low as 1 mumol/l, which can be achieved in humans, the results may be physiologically/therapeutically relevant.

Topics: Atherosclerosis; Biphenyl Compounds; Cardiovascular Diseases; Catalysis; Cells, Cultured; Chlorophyll; Chlorophyllides; Copper; Dose-Response Relationship, Drug; Endothelium, Vascular; Free Radical Scavengers; Free Radicals; Hemin; Humans; Hydrazines; Hydrogen Peroxide; Ions; Iron; Lipid Peroxidation; Lipids; Lipoproteins; Lipoproteins, LDL; Magnesium; Malondialdehyde; Models, Chemical; Octanols; Oxygen; Picrates; Protoporphyrins; Pyrazoles; Pyrimidines; Thiobarbituric Acid Reactive Substances; Thromboplastin; Time Factors; Tyrosine; Umbilical Veins; Water