Inhibition Of Superoxide Generation Research Articles

Trinorditerpenes from the roots of Flueggea virosa

Two trinorditerpenes, flueggrenes A and B (1 and 2), have been isolated from the roots of Flueggea virosa. Their structures were established by extensive analyses of spectroscopic data. The isolates were evaluated for anti-HCV activity, as well as the inhibition of superoxide anion generation and elastase release in response to FMLP/cytochalasin B.

Vitamin D Protects Human Endothelial Cells From Oxidative Stress Through the Autophagic and Survival Pathways

Recently, vitamin D (VitD) has been recognized as increasingly importance in many cellular functions of several tissues and organs other than bone. In particular, VitD showed important beneficial effects in the cardiovascular system. Although the relationship among VitD, endothelium, and cardiovascular disease is well established, little is known about the antioxidant effect of VitD. Our objective was to study the intracellular pathways activated by VitD in cultured human umbilical vein endothelial cells undergoing oxidative stress. Nitric oxide production, cell viability, reactive oxygen species, the mitochondrial permeability transition pore, membrane potential, and caspase-3 activity were measured during oxidative stress induced by administration of 200 μM hydrogen peroxide for 20 minutes. Experiments were repeated in the presence of specific vitamin D receptor ligand ZK191784. Pretreatment with VitD alone or in combination with ZK191784 is able to reduce the apoptosis-related gene expression, involving both intrinsic and extrinsic pathways. At the same time, it has been shown the activation of pro-autophagic beclin 1 and the phosphorylation of ERK1/2 and Akt, indicating a modulation between apoptosis and autophagy. Moreover, VitD alone or in combination with ZK191784 is able to prevent the loss of mitochondrial potential and the consequent cytochrome C release and caspase activation. The present study shows that VitD may prevent endothelial cell death through modulation of the interplay between apoptosis and autophagy. This effect is obtained by inhibiting superoxide anion generation, maintaining mitochondria function and cell viability, activating survival kinases, and inducing NO production.

Synthesis and structural characterization of an anti-inflammatory principle purified from Lindera aggregata

Linderaggrine A (1) was characterized from the roots of Lindera aggregata and its chemical structure was established by the spectral analysis and chemical transformation. The chemical preparation of 1 and its isomer 2 provide unambiguous evidences for the structural determination of the naturally isolated compound. In addition, the inhibition of superoxide anion generation and elastase release by human neutrophils in response to FMLP/cytochalasin B of these synthetic products had been examined and among the tested compounds, linderaggrine A (1) displayed significant potential against the superoxide anion generation.

Achyranthes bidentata Polypeptides Reduces Oxidative Stress and Exerts Protective Effects against Myocardial Ischemic/Reperfusion Injury in Rats

Achyranthes bidentata, a Chinese medicinal herb, is reported to be neuroprotective. However, its role in cardioprotection remains largely unknown. Our present study aimed to investigate the effects of Achyranthes bidentata polypeptides (ABPP) preconditioning on myocardial ischemia/reperfusion (MI/R) injury and to test the possible mechanisms. Rats were treated with ABPP (10 mg/kg/d, i.p.) or saline once daily for one week. Afterward, all the animals were subjected to 30 min of myocardial ischemia followed by 4 h of reperfusion. ABPP preconditioning for one week significantly improved cardiac function following MI/R. Meanwhile, ABPP reduced infarct size, plasma creatine kinase (CK)/lactate dehydrogenase (LDH) activities and myocardial apoptosis at the end of reperfusion in rat hearts. Moreover, ABPP preconditioning significantly inhibited superoxide generation, gp91phox expression, malonaldialdehyde formation and enhanced superoxide dismutase activity in I/R hearts. Furthermore, ABPP treatment inhibited PTEN expression and increased Akt phosphorylation in I/R rat heart. PI3K inhibitor wortmannin blocked Akt activation, and abolished ABPP-stimulated anti-oxidant effect and cardioprotection. Our study demonstrated for the first time that ABPP reduces oxidative stress and exerts cardioprotection against MI/R injury in rats. Inhibition of PTEN and activation of Akt may contribute to the anti-oxidant capacity and cardioprotection of ABPP.

Bioactive Secondary Metabolites of a Marine Bacillus sp. Inhibit Superoxide Generation and Elastase Release in Human Neutrophils by Blocking Formyl Peptide Receptor 1

It is well known that overwhelming neutrophil activation is closely related to acute and chronic inflammatory injuries. Formyl peptide receptor 1 (FPR1) plays an important role in activation of neutrophils and may represent a potent therapeutic target in inflammatory diseases. In the present study, we demonstrated that IA-LBI07-1 (IA), an extract of bioactive secondary metabolites from a marine Bacillus sp., has anti-inflammatory effects in human neutrophils. IA significantly inhibited superoxide generation and elastase release in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-activated neutrophils, but failed to suppress the cell responses activated by non-FPR1 agonists. IA did not alter superoxide production and elastase activity in cell-free systems. IA also attenuated the downstream signaling from FPR1, such as the Ca2+, MAP kinases and AKT pathways. In addition, IA inhibited the binding of N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein, a fluorescent analogue of FMLP, to FPR1 in human neutrophils and FPR1-transfected HEK293 cells. Taken together, these results show that the anti-inflammatory effects of IA in human neutrophils are through the inhibition of FPR1. Also, our data suggest that IA may have therapeutic potential to decrease tissue damage induced by human neutrophils.

Honokiol Dimers and Magnolol Derivatives with New Carbon Skeletons from the Roots of Magnolia officinalis and Their Inhibitory Effects on Superoxide Anion Generation and Elastase Release

Two honokiol dimers, houpulins A and B (1 and 2), and two magnolol derivatives, houpulins C and D (3 and 4), were isolated and characterized from an ethanol extract obtained from the roots of Magnolia officinalis. The chemical structures were determined based on spectroscopic and physicochemical analyses, which included 1D and 2D NMR, as well as mass spectrometry data. These four oligomers possess new carbon skeletons postulated to be biosynthesized from the coupling of three or four C6-C3 subunits. In addition, the new oligomers were evaluated for inhibition of superoxide anion generation and elastase release, and houpulin B (2) was identified as a new anti-inflammatory lead compound.

An epigenetic modifier enhances the production of anti-diabetic and anti-inflammatory sesquiterpenoids from Aspergillus sydowii

The addition of a DNA methyltransferase inhibitor, 5-azacytidine, to Aspergillus sydowii fungus culture broth changed its secondary metabolites profile. Analysis of the culture broth extract led to the isolation of three new bisabolane-type sesquiterpenoids: (7S)-(+)-7-O-methylsydonol (1), (7S,11S)-(+)-12-hydroxysydonic acid (2) and 7-deoxy-7,14-didehydrosydonol (3), along with eight known compounds. The isolated compounds were evaluated for their anti-diabetic and anti-inflammatory activities. Among the isolates, (S)-(+)-sydonol (4) did not only potentiate insulin-stimulated glucose consumption but also prevented lipid accumulation in 3T3-L1 adipocytes. Additionally, (S)-(+)-sydonol (4) exhibited significant anti-inflammatory activity through inhibiting superoxide anion generation and elastase release by fMLP/CB-induced human neutrophils. This is the first report on isolating a secondary metabolite with anti-diabetic and anti-inflammatory activities from microorganisms.

Anti-inflammatory Diterpenoids from Croton tonkinensis

Phytochemical investigation of the methanolic extract of Croton tonkinensis afforded two known kauranes (1, 2), eight new ent-kauranes (3-10), and 16 known ent-kaurane-type diterpenoids (12-27). In addition, 30 known compounds were identified by comparison of their physical and spectroscopic data with reported data. Among the isolated compounds, ent-18-acetoxykaur-16-en-15-one (20) displayed the most significant inhibition of superoxide anion generation and elastase release.

1,5-Diphenylpent-3-en-1-ynes and methyl naphthalene carboxylates from Lawsonia inermis and their anti-inflammatory activity

Lawsonia inermis (Lythraceae) known as henna is one of the most popular and ancient plants used in cosmetics and hair dying. It is cultivated for its leaves but other parts such as seeds, flowers, stem bark and roots are also used in traditional medicine for millennia. Henna tattoo paste also proved to be beneficial for wound healing and in several skin diseases suggesting potent anti-inflammatory activity. To evaluate henna anti-inflammatory activity, 31 compounds, including three 1,5-diphenylpent-3-en-1-yne derivatives, lawsochylin A-C and three methyl naphthalene carboxylates, lawsonaphthoate A-C, were isolated from the stems and leaves of henna utilizing a bioassay-guided fractionation. The structures of the compounds were elucidated by spectroscopic data. Two compounds, lawsochylin A and lawsonaphthoate A showed potent anti-inflammatory activity by inhibition of superoxide anion generation (IC(50)=1.80 and 1.90 μg/ml) and elastase release (IC(50)=1.58 and 3.17 μg/ml) of human neutrophils in response to fMLP or cytochalasin B. Moreover, the known compounds, luteolin, apigenin, 4S-4-hydroxy-α-tetralone, and 2-butoxysuccinic acid, also showed potent inhibition of superoxide anion generation (IC(50)=0.75-1.78 μg/ml) and elastase release (IC(50)=1.62-3.61 μg/ml).

Isolation and Synthesis of Melodamide A, a New Anti-inflammatory Phenolic Amide from the Leaves of Melodorum fruticosum

Together with twelve known compounds (2-13), melodamide A (1), a new phenolic amide possessing p-quinol moiety, was purified and characterized from the methanolic extracts of the leaves of Melodorum fruticosum. The structure of melodamide A (1) was established with a combination of 2D NMR experiments, HR-ESI-MS and X-ray analyses. The other known compounds were identified by comparison of their spectroscopic and physical data with those reported in the literature. Moreover, some isolated compounds were examined for their inhibitory activity towards superoxide anion generation and elastase release in human neutrophils. Among the tested compounds, 1, 3, and 5 exhibited strong inhibition of superoxide anion generation with IC50 values ranging from 5.25 to 8.65 µM. Furthermore, synthesis and biological evaluation of melodamide A (1) and its analogs (14a-p) were described.

UFM24, a novel natural product, inhibits superoxide generation and CD11b expression in activated human neutrophils

UFM24, a novel natural product, inhibits superoxide generation and CD11b expression in activated human neutrophils

New approach to the characterization and quantification of Antrodia cinnamomea benzenoid components utilizing HPLC-PDA, qNMR and HPLC-tandem MS: Comparing the wild fruiting bodies and its artificial cultivated commercial products

Antrodia cinnamomea (AC) is one of the Far East's treasured medicinal mushrooms and a major ingredient in different nutritional supplements targeting several serious ailments. Developing a sensitive simple quality control protocol for AC and its products is an unmet goal which we target in the current investigation through detecting its biomarkers. Among the AC components, benzenoid derivatives are considered therapeutically attractive due their anti-inflammatory and cytotoxic activities. We proposed a convenient method for concentrating the benzenoid-rich fraction (FNH), from AC wild fruiting bodies ethanolic extract (EEAC). Three benzenoids, 4,7-dimethoxy-5-methyl-1,3-benzodioxole (1), antrocamphin A (2) and 4,7-dimethoxy-5-methyl-6-(3-methylbut-3-en-1-ynyl)-1,3-benzodioxole (3) were purified and their structures were elucidated. Different wild AC samples and the separated benzenoids (1–3) exhibited anti-inflammatory activity through inhibiting superoxide anion generation and elastase release by human neutrophils in response to N-formyl-methionyl-leucyl-phenylalanine (FMLP)/cytochalasin B (CB). Compound 1 exhibited the most potent activity against superoxide anion generation (IC50 5.08μg/ml) while compounds 2 and 3 were less active (IC50>10μg/ml) implying the advantageous use of 1–3 as biomarkers for AC.HPLC-tandem MS analytical protocol was developed for the quantification of the three major benzenoids from different AC commercial products. The results showed that compound 1 is a unique characteristic biomarker for AC quality control. The concentrations of compounds 2 and 3 were higher in certain sources of AC fruiting bodies and were absent in mycelia, suggesting their usefulness as biomarkers for quality control of fruiting bodies products. The HPLC-tandem MS results were compared to the results obtained by quantitative NMR.

Overexpression of stanniocalcin-1 inhibits reactive oxygen species and renal ischemia/reperfusion injury in mice

Reactive oxygen species, endothelial dysfunction, inflammation, and mitogen-activated protein kinases have important roles in the pathogenesis of ischemia/reperfusion kidney injury. Stanniocalcin-1 (STC1) suppresses superoxide generation in many systems through induction of mitochondrial uncoupling proteins and blocks the cytokine-induced rise in endothelial permeability. Here we tested whether transgenic overexpression of STC1 protects from bilateral ischemia/reperfusion kidney injury. This injury in wild type mice caused a halving of the creatinine clearance; severe tubular vacuolization and cast formation; increased infiltration of macrophages and T cells; higher vascular permeability; greater production of superoxide and hydrogen peroxide; and higher ratio of activated ERK/activated JNK and p38, all compared to sham-treated controls. Mice transgenic for human STC1 expression, however, had resistance to equivalent ischemia/reperfusion injury indicated as no significant change from controls in any of these parameters. Tubular epithelial cells in transgenic mice expressed higher mitochondrial uncoupling protein 2 and lower superoxide generation. Pre-treatment of transgenic mice with paraquat, a generator of reactive oxygen species, before injury restored the susceptibility to ischemia/reperfusion kidney injury, suggesting that STC1 protects by an anti-oxidant mechanism. Thus, STC1 may be a therapeutic target for ischemia/reperfusion kidney injury.

Constituents from Vigna vexillata and their anti-inflammatory activity.

The seeds of Vigna genus are important food resources and there have already been many reports regarding their bioactivities. In our preliminary bioassay, the chloroform layer of methanol extracts of V. vexillata demonstrated significant anti-inflammatory bioactivity. Therefore, the present research is aimed to purify and identify the anti-inflammatory principles of V. vexillata. One new sterol (1) and two new isoflavones (2,3) were reported from the natural sources for the first time and their chemical structures were determined by the spectroscopic and mass spectrometric analyses. In addition, 37 known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature. Among the isolates, daidzein (23), abscisic acid (25), and quercetin (40) displayed the most significant inhibition of superoxide anion generation and elastase release.

Human Stanniocalcin-1 Suppresses Angiotensin II-Induced Superoxide Generation in Cardiomyocytes through UCP3-Mediated Anti-Oxidant Pathway

RationaleWe have previously shown increased cardiac stanniocalcin-1 (STC1) in patients with idiopathic dilated cardiomyopathy. STC1 localizes to the inner mitochondrial membrane and transgenic over-expression of STC1 is associated with increased energy utilization.ObjectiveWe examined the hypothesis that STC1 uncouples mitochondrial oxidative phosphorylation - to suppress superoxide generation and modulate neurohormonal effects on cardiomyocytes.Methods and ResultsCompared to WT mouse heart, STC1 Tg heart displays: 2-fold higher uncoupling protein 3 (UCP3) levels, but no effect on UCP2 protein; 40% lower ATP levels; but similar activities of respiratory chain complexes I-IV. In cultured adult rat and freshly-isolated mouse cardiomyocytes, rSTC1 induces UCP3, but not UCP2. Treatment of cardiomyocytes with STC1 decreases mitochondrial membrane potential and suppresses baseline and angiotensin II (Ang II)-induced superoxide generation. Furthermore, baseline superoxide generation is higher in freshly-isolated adult UCP3−/− mouse cardiomyocytes compared to WT, suggesting an important role for UCP3 in regulating cardiomyocyte ROS under physiologic conditions. Treatment of UCP3−/− cardiomyocytes with rSTC1 failed to suppress superoxide generation, suggesting that the effects of STC1 on superoxide generation in cardiomyocytes are UCP3-dependent.ConclusionSTC1 activates a novel anti-oxidant pathway in cardiac myocytes through induction of UCP3, and may play an important role in suppressing ROS in the heart under normal physiologic conditions and ameliorate the deleterious effects of Ang II-mediated cardiac injury. Importantly, our data point to a critical role for the mitochondria in regulating ROS generation in response to Ang II.

Anti-tumour promoting activity and antioxidant properties of girinimbine isolated from the stem bark of Murraya koenigii S.

Girinimbine, a carbazole alkaloid isolated from the stem bark of Murraya koenigii was tested for the in vitro anti-tumour promoting and antioxidant activities. Anti-tumour promoting activity was determined by assaying the capability of this compound to inhibit the expression of early antigen of Epstein-Barr virus (EA-EBV) in Raji cells that was induced by the tumour promoter, phorbol 12-myristate 13-acetate. The concentration of this compound that gave an inhibition rate at fifty percent was 6.0 µg/mL and was not cytotoxic to the cells. Immunoblotting analysis of the expression of EA-EBV showed that girinimbine was able to suppress restricted early antigen (EA-R). However, diffused early antigen (EA-D) was partially suppressed when used at 32.0 µg/mL. Girinimbine exhibited a very strong antioxidant activity as compared to α-tocopherol and was able to inhibit superoxide generation in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiated premyelocytic HL-60 cells more than 95%, when treated with the compound at 5.3 and 26.3 µg/mL, respectively. However girinimbine failed to scavenge the stable diphenyl picryl hydrazyl (DPPH)-free radical.

Estrogen-dependent inhibition of dextrose-induced endoplasmic reticulum stress and superoxide generation in endothelial cells

Increased oxidative stress and endoplasmic reticulum stress (ER stress) have been implicated in atherosclerosis. Estrogens have potent antioxidant activity but their effects on ER stress have not been well studied. Therefore, we studied the effects of estradiol and related sex steroids on dextrose-induced ER stress and superoxide (SO) generation in human umbilical vein endothelial cells (HUVECs). Oxidative stress was measured using hydroethidine fluorescence and MCLA chemiluminescence. ER stress was measured with an ER stress-sensitive secreted alkaline phosphatase (ES-TRAP) assay and by Western blot analysis of the expression of GRP78, JNK1, and phosphorylated JNK1, markers for ER stress. A supraphysiological dextrose concentration (27.5mM) increased ER stress and SO generation compared to treatment with a physiological concentration (5.5mM) of dextrose. In the presence of estradiol or testosterone (T), ER stress and SO generation were significantly reduced. In contrast to T-treated cells, dihydrotestosterone and 5-methyltestosterone were ineffective at alleviating ER stress or SO generation. When HUVECs were treated with T and the aromatase inhibitor 4-hydroxy-4-androstene-3,17-dione, T was no longer effective at suppressing ER stress or inhibiting SO generation. Changes in GRP78 expression and JNK activity in HUVECs support the results obtained in the ES-TRAP assay. These results indicate that dextrose-induced endoplasmic reticulum stress and superoxide generation are reversed by estradiol and testosterone; however, the latter requires aromatase-dependent conversion to estradiol.

Chemical Constituents from Farfugium Japonicum Var. formosanum

Two new eremophilenolides, 6beta,8beta,10beta-trihydroxyeremophil-7(11)-en-12,8-olide (1) and 3beta-acetoxy-8alpha-hydroxy-6beta-methoxyeremophila-7(11),9-dien-12,8-olide (2) along with twenty-nine other compounds were obtained from the methanolic extracts of the aerial parts and rhizomes of Farfugium japonicum (L.) Kitam. var. formosanum (Hayata) Kitam. (Compositae = Asteraceae). The structures of the isolated compounds were characterized and identified by spectral techniques. Compounds 5, 6, 10, 12-24, 29, and 30, were reported for the first time from this genus. Cytotoxicity and anti-inflammatory activity of the isolated compounds were evaluated. Compounds 3 and 16 possessed moderate cytotoxicity against human breast cancer cell line (MCF 7). Compounds 3, 16, 25 and 26 exhibited moderate cytotoxicity against hepatoma cells (Hep G2 and Hep 3B). With respect to the anti-inflammatory activity, compounds 15 and 16 (each 10 microg/mL) inhibited superoxide anion generation by human neutrophils in response to fMLP/CB by 92.0% and 87.3%, respectively.

Anti-inflammatory effect of three iridoids in human neutrophils

To verify the anti-inflammatory potency of iridoids, three iridoids (two natural, loganic acid: LA; geniposide: GE; and an artefact, 7(S)-n-butyl morroniside: BM) were investigated in vitro on the inhibition of superoxide generation in human neutrophils. All compounds showed inhibitory effect on fMLP-induced superoxide generation in a concentration-dependent manner with the following order: BM>LA>GE. BM exhibits potent inhibitory activity on superoxide anion induced by PMA, while LA and GE showed weak effect. When AA was used as stimulus, the generation of superoxide anion was suppressed by BM in a concentration-dependent manner. LA and GE exhibit both sides effect on superoxide generation.

ChemInform Abstract: Bioactive Components from the Heartwood of Pterocarpus santalinus.

AbstractPterolinus K (I) and pterolinus L (II) are isolated from the P.