Inhibited H2 O2 Research Articles

Synergistic antioxidant effects of petunidin and lycopene in H9c2 cells submitted to hydrogen peroxide: Role of Akt/Nrf2 pathway.

Phenolics and carotenoids coexist in fruits and vegetables and could possess interaction effects after consumption. The present study aims to elucidate the possible mechanisms of the antioxidant interactions between anthocyanins and carotenoids using petunidin and lycopene as examples in hydrogen peroxide (H2 O2 )-induced heart myofibroblast cell (H9c2) line model. The results revealed that petunidin and lycopene showed antioxidant effects and petunidin in a larger proportion mixed with lycopene, for example, petunidin: lycopene = 9:1 significantly protected against the loss of the cell viability (8.98±1.03%) and intracellular antioxidant enzyme activities of superoxide dismutase (SOD, 27.07±3.51%), catalase (CAT, 29.51±6.12%), and glutathione peroxidase (GSH-Px, 20.33±2.65%). Moreover, the messenger RNA (mRNA) and protein expressions of NAD(P)H quinone reductase (NQO1) and heme oxygenase (HO-1) of the nuclear factor erythrocyte 2-related factor 2 (Nrf2) signaling pathway were significantly induced in petunidin, lycopene, and synergistic combinations, suggesting that the antioxidant action was through activating the Nrf2 antioxidant response pathway. This was further validated by Nrf2 siRNA, and the results that petunidin significantly induced more of NQO1 expression and lycopene more of HO-1 suggested that the synergism may be a result of concerted actions by the two compounds on these two different target genes of the Nrf2 pathway. The two compounds also significantly increased the phosphorylation of Akt in synergistic combinations. Findings of the present study demonstrated that petunidin and lycopene exerted synergistic antioxidant effects when petunidin in a larger proportion in the combinations and contribute to the prevention of cellular redox homeostasis, which might provide a theoretical basis for phenolics and carotenoids playing beneficial effects on the cardiovascular risk. PRACTICAL APPLICATION: In this study, we revealed that the combined treatments of petunidin and lycopen inhibited H2 O2 -induced oxidative damage in myocardial cells. Moreover, the treatments contributed to the Nrf2 pathway and the restoration of cellular redox homeostasis might provide a theoretical basis for phenolics and carotenoids playing beneficial effects on the cardiovascular risk.

CSF1-associated decrease in endometrial macrophages may contribute to Asherman's syndrome.

Asherman's syndrome (AS) is characterized by endometrial fibrosis leading to intrauterine adhesions and symptoms like hypomenorrhea, infertility, and recurrent pregnancy loss. Macrophages are key regulators of inflammation, tissue repair, regeneration, and fibrosis. However, the role of macrophages in AS remains unclear. Endometrial biopsies of AS patients and controls were collected during the late proliferating phase of menstrual cycle. Fibrosis and proliferation markers were detected by Masson's trichrome staining and immunohistochemistry. Macrophages were examined by immunostaining and flow cytometry. The expression levels of CCL2, CSF1, CSF1R, and GM-CSF were detected by quantitative real-time polymerase chain reaction (q-PCR) and immunohistochemistry. A well-differentiated endometrial cell line Ishikawa (IK) was used for in vitro studies. Macrophages differentiating from THP-1 monocytic cells were polarized by IL-4/IL-13. Their culture supernatants (M(IL-4/13)-S) were applied to H2 O2 or bleomycin-damaged IK cells. In AS patients, endometrial stroma was replaced by fibrous tissue and cell proliferation was reduced. Macrophages in endometrial tissue were mainly alternative activated macrophages and their number was significantly decreased in AS patients. The CSF1 expression level was reduced in AS patients. M(IL-4/13)-S promoted the growth and migration of IK cells and inhibited H2 O2 -induced apoptosis. M(IL-4/13)-S protected IK cells from bleomycin-induced fibrosis. Macrophages are critical cells involved in the process of endometrial repair and fibrosis. The decreased amount of endometrial macrophages may be attributed to the reduced expression level of CSF1. Manipulation of macrophage activation/function may provide a novel therapeutic target for AS.

Inhibition effect of super atmospheric O2 packaging on H2O2-production and the key enzymes of ligin biosynthesis in fresh-cut Chinese cabbage

Fresh-cut Chinese cabbage was packaged by super atmospheric O2, and held at 4 °C, taking air packaging as control. The contents of lignin and H2O2 and, the activities and transcription expressions of four key enzymes of lignin synthesis, i.e., phenylalanine ammonia-lyase (PAL), 4-coumarate: CoA ligase (4-CL), cinnamyl alcohol dehydrogenase (CAD) and peroxidase (POD), were determined in the cabbage. The results showed that the lignin content of the cabbage packaged by super atmospheric O2 was markedly reduced (p < 0.05) in comparison with control from day 3 to 12 during storage at 4 ºC. The H2O2 concentrations in fresh-cut Chinese cabbage under super atmospheric O2 was lower than that of control during storage at 4 °C and, significantly lower (p < 0.05) on day 8 of storage. The activities of PAL, 4-CL, CAD and POD under super atmospheric O2 packaging were significantly lower (p < 0.05) than that of control from day 3 to 12 of storage at 4 ºC, except for 4-CL on day 9. Moreover, the transcript expressions of POD genes in the cabbage in super atmospheric O2 were dramatically reduced compared with control on day 8 of storage at 4 °C. It is suggested that the suppression of lignin synthesis of the cabbage under super atmospheric O2 packaging was attributed to the inhibition of H2O2, which feedback-regulated the key enzymes activities directly or indirectly.

Phytochemical screening, antioxidant, analgesic and acetylcholinesterase inhibitory effects of Pittosporum tobira leaves

The objective of this study was to determine in the first time the phytoconstituents and the in vitro antioxidant and enzyme inhibitory properties of the ethanol extract of P. tobira leaves (PTL) and to assess its in vivo pharmacological action on pain.Phytochemical screening was done using standard protocols. The antioxidant potential was investigated using two methods including hydrogen peroxide and DPPH radical-scavenging assays. An assessment of the anti-acetylcholinesterase activity of PTL was performed. The analgesic activity was also evaluated using a hot plate and acetic acid assays.Alkaloid, saponins, cardiac glycoside, terpenoids, flavonoids and reducing sugars were found to be present in the leaf of P. tobira. PTL showed a significant antioxidant capacity by inhibition of DPPH radical (EC50 = 143.4 µg/mL) and H2O2 (EC50 = 46.29± 2.1 µg/mL) scavenging activities. Moreover, acetylcholinesterase enzyme was strongly inhibited by PTL with the IC50 value of 100.79 µg/mL. The analgesic effect of PTL was evaluated in mice after intraperitoneal injection of acetic acid (1%, 10 mL/kg, ip). The results showed that PTL reduced significantly the abdominal writhing in mice with an inhibition percentage of 14.78%, comparable with standard paracetamol (10.31%). Furthermore, PTL (350 mg / kg) increased remarkably the reaction time of mice with relatively extended duration of stimulation in the hot-plate test when compared to the control groups.We conclude that the leaf extract of P. tobira possesses potential antioxidant, anti-nociceptive, and anti-acetylcholinesterase properties which could be assigned to the presence of bioactive compounds in its composition.

Nanoplasmonic sensing of NADH by inhibiting the oxidative etching of gold nanorods

The plasmonic spectral sensing method based on the etching of gold nanorods has been a powerful tool in the field of biomedical detection. Among the plasmonic etching sensors, the most popular sensing strategy is the “positive oxidative etching” plasmonic sensor that is based on plasmon blue-shifting due to nanorod shortening. In this study, we proposed a nanoplasmonic detection of dihydronicotinamide adenine dinucleotide (NADH) based on negative oxidative etching: NADH-mediated inhibition of H2O2 induced gold nanorods etching. In the presence of NADH, the bromine intermediates (Br3− and Br2) used for etching gold nanorods were reduced and consumed, inhibiting the etching rate and resulting in a small blue-shift of the longitudinal plasmon band (LPB). This shift can be utilized to sense the presence of NADH. Under the optimal reaction conditions, the LPB difference (Δλ) of etched gold nanorods and the concentration of NADH had a good linear relationship in the range of 0–4.9 × 10−6 mol/L. The nanoplasmonic sensing showed a satisfactory preference for NADH over other common substances tested. It was successfully applied to the detection of NADH in PBS solution. This system provides a platform for the detection of targets in NADH-generated enzyme catalysis.

Hydrogen peroxide and nitric oxide are involved in programmed cell death induced by cryopreservation in Dendrobium protocorm-like bodies

Programmed cell death (PCD) plays a key role in animal tissue cell death following cryopreservation. However, there are few studies evaluating the plant PCD characteristics induced by cryopreservation and the possible role of signal molecules in PCD. Here, we performed cell ultrastructural observation and evaluation of PCD-regulating gene expression, caspase-3-like activity, and hydrogen peroxide (H2O2) and nitric oxide (NO) contents occurring in Dendrobium protocorm-like bodies (PLBs) cryopreserved by vitrification. The main changes in cell ultrastructure were noted at the plant vitrification solution 2 (PVS2) dehydration stage with severe plasmolysis, chromatin condensation and vesicle formation. Liquid nitrogen exposure increased autophagy activity with the appearance of many autophagic vesicles. Expression of the autophagy-related protein 8C gene (Atg 8C) and reticulon-like protein B8 gene (Rtnl B8) was increased at the preculture and cooling-rewarming stages, while bax inhibitor 1-like gene (BIL 1) expression was decreased at the preculture and PVS2 dehydration stages compared with expression levels in fresh PLBs (CK). Caspase-3-like activity was low at the preculture stage but increased significantly with the treatment of loading and PVS2 dehydration and finally reached a peak at the stage of cooling-rewarming. Both H2O2 and NO began to increase at the preculture stage, reached the highest value at the loading stage, and then decreased at the late stage of cryopreservation. Catalase (CAT) and 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) addition at the preculture stage significantly increased survival and decreased caspase-3-like activity in cryopreserved PLBs. These results indicated that the cryopreservation protocol, especially PVS2 dehydration and cooling-rewarming, induced PCD in D. nobile PLBs. H2O2 and NO produced at the preculture stage may also be involved. Cryopreservation protocol by vitrification, especially the PVS2 dehydration and cooling-rewarming, induced programmed cell death in PLBs. Inhibition of H2O2 and NO produced at the preculture stage can decrease caspase-3-like activity and improve PLBs viability.

Synthesis, structure-activity relationship studies and biological characterization of new [1,2,4]triazolo[1,5-a]pyrimidine-based LSD1/KDM1A inhibitors

The histone lysine specific demethylase 1 (LSD1/KDM1A) is implicated in the development of cancers, targeting LSD1 has been recognized as a promising strategy for cancer therapy. To date, some small-molecule inhibitors are currently being investigated in clinical trials. Herein we report the design, synthesis and biochemical characterization of [1,2,4]triazolo[1,5-a]pyrimidine derivatives as new LSD1 inhibitors. Of these compounds, compound C26 inhibited LSD1 in a reversible manner (IC50 = 1.72 μM) and showed selectivity to LSD1 over MAO-A/B. Besides, compound C26 displayed FAD-competitive binding to LSD1. Interestingly, C26 did not inhibit horseradish peroxidase (HRP) and quench H2O2, thus excluding the possibility that LSD1 inhibition by C26 was due to the HRP inhibition and consumption of H2O2. In LSD1 overexpressed A549 cells, compound C26 concentration-dependently induced accumulation of H3K4me1/me2 and H3K9me2 and showed cellular target engagement to LSD1. Additionally, compound C26 significantly inhibited migration of A549 cells in a concentration-dependent manner, further western blot analysis showed that C26 increased expression levels of epithelial cell markers E-Cadherin and Claudin-1, down-regulated mesenchymal cell marker N-Cadherin and the upstream transcription factors Snail and Slug. Docking studies were also performed to rationalize the potency of C26 toward LSD1. To conclude, the [1,2,4]triazolo[1,5-a]pyrimidine could serve as a promising scaffold for the development of new LSD1 inhibitors.

Organic Pollutant Degradation in Water by the Vacuum-Ultraviolet/Ultraviolet/H2O2 Process: Inhibition and Enhancement Roles of H2O2.

A vacuum-ultraviolet/ultraviolet (VUV/UV) mercury lamp was found to be a highly efficient radiation source for UV-based advanced oxidation processes (AOPs). If this lamp could enhance the UV/H2O2 process, it would be very attractive. Hence, we have investigated sulfamethazine (SMN) degradation by the VUV/UV/H2O2 process based on a bench-scale mini-fluidic VUV/UV photoreaction system (MVPS), a pilot reactor, and a model analysis. At high [SMN]0 in the MVPS, the apparent SMN degradation rate constant ( k'app) increased with increasing H2O2 dose, while at low [SMN]0, k'app decreased with increasing H2O2 dose; this behavior was unexpected. Meanwhile, at low [SMN]0 in a pilot reactor, H2O2 induced just a slight enhancement in the VUV/UV/H2O process. A numerical simulation of the process suggested that for an integrated AOP (i.e., VUV/UV/H2O2) consisting of various component AOPs, H2O2 could inhibit the component AOPs with HO* that did not originate from H2O2 (e.g., VUV photolysis of water). The apparent H2O2 role in the integrated AOPs was dependent on the contribution comparison between component AOPs that involved HO* that did or did not originate from H2O2. These results revealed important information regarding the application of the VUV/UV/H2O2 process in water treatment.

Transactive response DNA binding protein of 43/histone deacetylase 6 axis alleviates H 2 O 2 -induced retinal ganglion cells injury through inhibiting apoptosis and autophagy.

Oxidative damage is believed to contribute to the pathogenesis of diabetic retinopathy (DR). The current study aimed to detect the effects of transactive response DNA binding protein of 43 (TDP-43) on cell damage induced by hydrogen peroxide (H2 O2 ) in retinal ganglion cells (RGCs) and to investigate the molecular mechanisms involved in this process. We observed that TDP-43 was highly expressed in RGC-5 cells induced by H2 O2 , and that repression of TDP-43 obviously ameliorated H2 O2 -induced RGC-5 cell injury. In addition, loss of TDP-43 profoundly mitigated H2 O2 -triggered oxidative stress by decreasing the production of intracellular reactive oxygen species and the activity of oxidative stress indicator malondialdehyde, as well as enhancing the content of antioxidant enzymes superoxide dismutase, glutathione peroxidase and catalase to restore the antioxidant defense system. Moreover, suppression of TDP-43 obviously obstructed H2 O2 -induced apoptosis. Meanwhile, knockdown of TDP-43 attenuated the expression of the proapoptotic proteins Bax and Cytochrome c, elevated the anti-apoptotic protein Bcl-2, and suppressed the activation of caspase 3 in H2 O2 -induced RGC-5 cells. Moreover, elimination of TDP-43 inhibited H2 O2 -triggered autophagy, which appeared as decreased expression of LC3II/I and Beclin-1, along with p62 degradation. Importantly, silencing of TDP-43 diminished the expression of histone deacetylase 6 (HDAC6), and HDAC6 also abolished the inhibitory effect of TDP-43 inhibition on H2 O2 -induced apoptosis and autophagy. Collectively, our findings demonstrated that depletion of TDP-43 may protect RGC-5 cells against oxidative stress-mediated apoptosis and autophagy by suppressing its target HDAC6. Thus, the TDP-43/HDAC6 axis might be a promising strategy for the treatment of DR.

Downregulation of long noncoding RNA Sox2ot protects PC-12 cells from hydrogen peroxide-induced injury in spinal cord injury via regulating the miR-211-myeloid cell leukemia-1 isoform2 axis.

This study aimed to investigate the effects and possible mechanisms of long noncoding RNA (lncRNA) Sox2 overlapping transcript (Sox2ot) on hydrogen peroxide (H2 O2 )-induced injury in pheochromocytoma (PC-12) cells. PC-12 cells were treated with H2 O2 to cell injury. The cells were transfected with short-hairpin RNA directed against Sox2ot (sh-Sox2ot), small interfering RNA directed against myeloid cell leukemia-1 (MCL-1) isoform2 (si-MCL-1), a miR-211 mimic, a miR-211 inhibitor, and their negative controls. Under different transfected treatments, cell viability, migration, invasion, and apoptosis as well as the expressions of apoptosis- and autophagy-related proteins were investigated. Besides, the regulatory relationships between Sox2ot and miR-211, miR-211 and MCL-1, as well as between MCL-1 and the protein kinase B (Akt)/mammalian target of the rapamycin (mTOR)/p70 ribosomal S6 protein kinase (p70S6K) signaling pathway were explored. Suppression of Sox2ot inhibited H2 O2 -induced PC-12 cell injury by increasing cell viability, migration, invasion, and decreasing apoptosis and autophagy. Moreover, suppression of Sox2ot increased miR-211 expression and alleviated H2 O2 -induced injury in PC-12 cells possibly via upregulation of miR-211. Furthermore, MCL-1 isoform2 was identified as a direct target of miR-211 and could be negatively regulated by miR-211. Suppression of miR-211 aggravated H2 O2 -induced cell injury by regulation of MCL-1 isoform2. Besides, inhibition of miR-211 suppressed the activation of the Akt/mTOR/p70S6K signaling pathway in H2 O2 -treated PC-12 cells, which was reversed after knockdown of MCL-1 isoform2 at the same time. Our findings indicate that downregulation of Sox2ot may protect PC-12 cells from H2 O2 -induced injury in SCI via targeting the miR-211/MCL-1 isoform2 axis. MCL-1 isoform2 may further regulate the activation of the Akt/mTOR/p70S6K pathway to mediate H2 O2 -induced injury. The Sox2ot-miR-211-MCL-1 isoform2 axis may be a promising therapeutic strategy for SCI.

Antioxidant effect of human placenta hydrolysate against oxidative stress on muscle atrophy.

Sarcopenia, which refers to the muscle loss that accompanies aging, is a complex neuromuscular disorder with a clinically high prevalence and mortality. Despite many efforts to protect against muscle weakness and muscle atrophy, the incidence of sarcopenia and its related permanent disabilities continue to increase. In this study, we found that treatment with human placental hydrolysate (hPH) significantly increased the viability (approximately 15%) of H2 O2 -stimulated C2C12 cells. Additionally, while H2 O2 -stimulated cells showed irregular morphology, hPH treatment restored their morphology to that of cells cultured under normal conditions. We further showed that hPH treatment effectively inhibited H2 O2 -induced cell death. Reactive oxygen species (ROS) generation and Mstn expression induced by oxidative stress are closely associated with muscular dysfunction followed by atrophy. Exposure of C2C12 cells to H2 O2 induced abundant production of intracellular ROS, mitochondrial superoxide, and mitochondrial dysfunction as well as myostatin expression via nuclear factor-κB (NF-κB) signaling; these effects were attenuated by hPH. Additionally, hPH decreased mitochondria fission-related gene expression (Drp1 and BNIP3) and increased mitochondria biogenesis via the Sirt1/AMPK/PGC-1α pathway and autophagy regulation. In vivo studies revealed that hPH-mediated prevention of atrophy was achieved predominantly through regulation of myostatin and PGC-1α expression and autophagy. Taken together, our findings indicate that hPH is potentially protective against muscle atrophy and oxidative cell death.

Regulation of monocyte redox balance by 1,8-cineole (eucalyptol) controls oxidative stress and pro-inflammatory responses in vitro: A new option to increase the antioxidant effects of combined respiratory therapy with budesonide and formoterol?

Abstract Background Airway mucus hypersecretion is the typical feature of COPD and asthma. Hypersecretion is caused by reactive oxygen species (ROS) and links the COPD-bronchitis phenotype to frequent exacerbations. Since the monoterpene 1,8-cineole is known for its secretolytic activity, we studied the antioxidant activity of 1,8-cineole. Methods Using a culture model of fetal calf serum (FCS)-stimulated human monocytes, we determined the effects of 1,8-cineole, at therapeutic concentrations (10−10–10−5 M) on superoxide anions (O2−), superoxide dismutase (SOD), hydrogen peroxide (H2O2) and of LPS-stimulated 8-isoprostanes (8-IsoP) and TNF-α. The effect of formoterol (F), budesonide (BUD), BUD + F without and with 1,8-cineole were determined on O2−-release. Results 1,8-cineole (10−5 M) strongly inhibited O2− (−53%, p Conclusions We report an inhibition of superoxide anions, balancing partial dismutation of superoxide anions and independent inhibition of H2O2 by 1,8-cineole. These results suggest a non-specific combined, antioxidant and anti-inflammatory mode of action of 1,8-cineole as bifunctional drug for further clinical evaluation in mild to severe COPD and as adjunctive therapy to control disease progression.

A Comparison Investigation on Antioxidant Activities, Physicochemical Properties and Phytochemical Contents of Kiwifruit Genotypes and Cultivars

ABSTRACTThe present work was conducted to find the physicochemical properties, chemical components and antioxidant capacity of kiwifruit hydroalcoholic extracts (B-31, HO-1-14, J-242, Bruno, Greenlight, Hayward, Monty, Topstar) grown Yalova, Turkey. Phytochemical tests were performed to determine total phenolic, flavonoid and ascorbic acid. Moreover, the kiwifruit extracts were subjected to evaluate their antioxidant potential using different in vitro assays such as total antioxidant, inhibition of lipid peroxidation, reducing power, metal chelating, free radical, H2O2 and superoxide anion scavenging activities at 50–500 μg mL−1, and also found EC50 and IC50 values. The soluble solid content (SSC), titratable acidity (TA) and pH were analyzed in all the genotypes and cultivars. The highest total phenolic, flavonoid and ascorbic acid content were found in J-242 (89.53 mg GAE/100 g), J-242 (109.13 mg QE/100 g) and HO-1-14 (64.15 mg/100 g), respectively. The linoleic, palmitic, stearic and oleic acid methyl esters were detected in all kiwifruit extracts by GC/MS. Significant differences were found between genotypes and cultivars in the antioxidant tests. The extracts showed high inhibition of lipid peroxidation and compared to standards, significantly (p < 0.05). The GC/MS analyses confirmed quantitative variability in the antioxidant profiles. The SSC, TA and pH of kiwifruit genotypes and cultivars showed a moderate level. The key parameters for the most active kiwifruit included the following: total antioxidant activity for B-31, H2O2 scavenging activity for J-242 and metal chelating activity for Topstar. In conclusion, this study exhibited the important role played by the genotypes and cultivars background on the chemical content and antioxidant profiles.

Nobiletin protects human retinal pigment epithelial cells from hydrogen peroxide-induced oxidative damage.

Nobiletin(3',4',5,6,7,8-hexamethoxyflavone), a dietary polymethoxylated flavonoid found inCitrusfruits, has been reported to have antioxidant effect. However, the effect of nobiletin on human retinal pigment epithelium (RPE) cells induced by hydrogen peroxide (H2 O2 ) is still unclear.Therefore, we investigated the protective effect of nobiletin against H2 O2 -induced cell death in RPE cells. Our results demonstrated that nobiletin significantly increased cell viability from oxidative stress. Nobiletin inhibited H2 O2 -induced ROS production and caspase-3/7 activity in ARPE-19 cells. Furthermore, nobiletin significantly increased Akt phosphorylation in ARPE-19 cells exposed to H2 O2 . Meanwhile, LY294002, an inhibitor of PI3K/Akt, abolished the protective effect of nobiletin against H2 O2 -induced decreased cell viability and increased caspase-3/7 activity in ARPE-19 cells. In summary, these data show that nobiletin protects RPE cells against oxidative stress through activation of the Akt-signaling pathway. Thus, nobiletin should be an oxidant that attenuates the development of age-related macular degeneration.

Hollow Pd–Sn Nanocrystals for Efficient Direct H2O2 Synthesis: The Critical Role of Sn on Structure Evolution and Catalytic Performance

The development of efficient catalysts with high activity and selectivity for the direct synthesis of H2O2 from H2 and O2 is highly desirable yet challenging. Herein, a series of Pd–Sn bimetallic nanocrystals with hollow structure have been successfully created as highly active and selective catalysts for direct H2O2 synthesis. We found that the introduction of Sn played an important role on the morphology evolution and composition control of the hollow Pd–Sn nanocrystals. Significantly, after rapid thermal treatment, the obtained hollow Pd–Sn/TiO2 catalysts can deliver complete inhibition of H2O2 decomposition/hydrogenation, resulting in a large activity enhancement for the H2O2 production. The H2 selectivity could be further improved by using water as the reaction solvent. Further investigation showed that the large activity enhancement of hollow Pd–Sn/TiO2 catalysts for the direct H2O2 synthesis can be attributed to the presence of PdO, the ensemble effect between the Pd and Sn, and the interface effec...

Chemical analyzes and antioxidant activities of essential oils of four wild Mentha species growing in the Tokat and its districts

The current work evaluated the chemical compositions of the essential oils (EOs) extracted from Mentha longifolia subsp. typhoides (Briq.) Harley var. typhoides PH. Davis, Mentha spicate L. subsp.spicata, Mentha longifolia (L.) Hudson subsp.longifolia and Mentha villoso nervata Opiz from gowning in the different locations of Tokat. The antioxidant activities of EOs were tested using total antioxidant activity, reducing power, inhibition of lipid peroxidation, metal chelating, H2O2, DPPH˙ and O2˙- scavenging activities. The chemical compositions of EOs were determined by GC and GC-MS. Significant differences were recorded between the percentages of many constituents depending on the geographical. The most important components were identified consecutively: linalool (nd-62.80%), menthone (0.31-60.81%), pulegone (nd-21.52%), isomenthone (nd-30.15%) and piperitoneoxide (nd-68.92%). The inhibition of lipid peroxidation, O2˙- and H2O2 scavenging activities of the EOs were very effective but their reduction power values were low. The results obtained validate that EOs of four Mentha species possess a source of antioxidant potential for medicinal and foods.

Evaluation of Hemolytic and Anti-Hemolytic Activity of the Aerial Parts of Sonchus Oleraceus Extracts

Plants have been used as alternative remedy for the treatment of various ailments since ancient times. The present study aimed to evaluate some of the biological activities of the plant Sonchus oleraceus in vitro including the hemolytic and antihemolytic effect. Hydromethanolic 80% and aqueous extracts of the aerial parts of plant were prepared using ultrasound-assisted extraction. Phyto-chemical analysis, hemolytic and anti-hemolytic activity of both extracts of Sonchus oleraceus were assessed. Phyto-chemical screening revealed the presence of tannins, carbohydrates, flavonoids, saponins, and phenolic compounds in both extracts. Hemolytic activity assessment has been conducted, using spectrophotometric method. The extracts had low hemolytic effect towards human erythrocytes in concentration-dependent manner.The extracts showed moderate membrane stabilizing effect against hypotonic-induced hemolysis at concentration range of (250-1000 µg/ml). This study also showed that extracts had potential antioxidant activity through the inhibition of H2O2 induced hemolysis. Both extracts showed remarkable antihemolytic activity against H2O2 induced hemolysis at all tested concentrations. It was concluded that the extracts of S. oleraceus manifest low hemolytic effect, and had antihemolytic activity. However, these effects need to be confirmed using in vivo models.

Role of NADPH Oxidase-4 in Human Endothelial Progenitor Cells.

Introduction: Endothelial progenitor cells (EPCs) display a unique ability to promote angiogenesis and restore endothelial function in injured blood vessels. NADPH oxidase 4 (NOX4)-derived hydrogen peroxide (H2O2) serves as a signaling molecule and promotes endothelial cell proliferation and migration as well as protecting against cell death. However, the role of NOX4 in EPC function is not completely understood.Methods: EPCs were isolated from human saphenous vein and mammary artery discarded during bypass surgery. NOX4 gene and protein expression in EPCs were measured by real time-PCR and Western blot analysis respectively. NOX4 gene expression was inhibited using an adenoviral vector expressing human NOX4 shRNA (Ad-NOX4i). H2O2 production was measured by Amplex red assay. EPC migration was evaluated using a transwell migration assay. EPC proliferation and viability were measured using trypan blue counts.Results: Inhibition of NOX4 using Ad-NOX4i reduced Nox4 gene and protein expression as well as H2O2 formation in EPCs. Inhibition of NOX4-derived H2O2 decreased both proliferation and migration of EPCs. Interestingly, pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) decreased NOX4 expression and reduced survival of EPCs. However, the survival of EPCs was further diminished by TNF-α in NOX4-knockdown cells, suggesting that NOX4 has a protective role in EPCs.Conclusion: These findings suggest that NOX4-type NADPH oxidase is important for proliferation and migration functions of EPCs and protects against pro-inflammatory cytokine induced EPC death. These properties of NOX4 may facilitate the efficient function of EPCs which is vital for successful neovascularization.

Involvement of endogenous antioxidant systems in the protective activity of pituitary adenylate cyclase-activating polypeptide against hydrogen peroxide-induced oxidative damages in cultured rat astrocytes.

Astroglial cells possess an array of cellular defense mechanisms, including superoxide dismutase (SOD) and catalase antioxidant enzymes, to prevent damages caused by oxidative stress. Nevertheless, astroglial cell viability and functionality can be affected by significant oxidative stress. We have previously shown that pituitary adenylate cyclase-activating polypeptide (PACAP) is a potent glioprotective agent that prevents hydrogen peroxide (H2 O2 )-induced apoptosis in cultured astrocytes. The purpose of this study was to investigate the potential protective effect of PACAP against oxidative-generated alteration of astrocytic antioxidant systems. Incubation of cells with subnanomolar concentrations of PACAP inhibited H2 O2 -evoked reactive oxygen species accumulation, mitochondrial respiratory burst, and caspase-3 mRNA level increase. PACAP also stimulated SOD and catalase activities in a concentration-dependent manner, and counteracted the inhibitory effect of H2 O2 on the activity of these two antioxidant enzymes. The protective action of PACAP against H2 O2 -evoked inhibition of antioxidant systems in astrocytes was protein kinase A, PKC, and MAP-kinase dependent. In the presence of H2 O2 , the SOD blocker NaCN and the catalase inhibitor 3-aminotriazole, both suppressed the protective effects of PACAP on SOD and catalase activities, mitochondrial function, and cell survival. Taken together, these results indicate that the anti-apoptotic effect of PACAP on astroglial cells can account for the activation of endogenous antioxidant enzymes and reduction in respiration rate, thus preserving mitochondrial integrity and preventing caspase-3 expression provoked by oxidative stress. Considering its powerful anti-apoptotic and anti-oxidative properties, the PACAPergic signaling system should thus be considered for the development of new therapeutical approaches to cure various pathologies involving oxidative neurodegeneration. We propose the following cascade for the glioprotective action of Pituitary adenylate cyclase-activating polypeptide (PACAP) against H2 O2 -induced astrocyte damages and cell apoptosis in cultured rat astrocytes. PACAP, through activation of its receptor, PAC1-R, and the protein kinase A (PKA), protein kinase C (PKC), and MAP-kinases signaling pathways, prevents accumulation of ROS andinhibition of SOD and catalase activities. This allows the preservation of mitochondrial membrane integrity and the reduction in caspase-3 activation induced by H2 O2 . These data may lead to the development of new strategies for cerebral injury treatment. Cat, catalase; Cyt. C, cytochrome C; SOD, superoxide dismutase.

Studies on Inhibition of H2O2 Induced TGF–β1 Expression in Peripheral Blood Mononuclear Cells by Novel Pyridine Appended Lutein Derivative

Lutein a hydroxy carotenoid belonging to xanthophyll group having a hydroxylgroup attached to either end of the molecule, making it react more strongly with singlet oxygen than other carotenoids. In the present study, Lutein was modified by appending pyridine moiety for increased antioxidant activity and its ability to inhibit H2O2 induced TGF-β1 expression in peripheral blood mononuclear cells was investigated. Lutein was treated with Isonicotinic acid (Pyridine-4-carboxylic acid) in thepresence of DCC and DMF as solvent medium to obtain pyridine appended Lutein (2.28mg/ml). The pyridine appended Lutein was purified using silica gel-G (60–120mesh) column, further by HPLC and fractions were eluted at the rate of 1ml/min using water, acetonitrile, methanol and dichloromethane as mobile phase in the ratio 0.5:9.5:67.5:22.5. A major peak was obtained at 454nm with retention time of 1.60min. In dose dependent study, Pyridine appended Lutein at 0.42µmoles showed a maximum of 91.6% of DPPH radical scavenging activity in comparison to unmodified Lutein (80.76%). Unmodified Lutein showed maximum activity (86.18% at 1.25µmoles) with 2.97 folds higher than Pyridine appended Lutein. TGF–β1 expression in H2O2 (3mM) treated peripheral blood mononuclear cells was inhibited by 83.14% (152.1pg/ml) and 76.21% (214.62pg/ml) at 0.92µmoles of Pyridine appended Lutein and unmodified Lutein respectively compared to H2O2 treated cells (902.15pg/ml) without test samples. In conclusion, Pyridine appended Lutein showed higher DPPH radical scavenging activity and inhibited H2O2 induced TGF–β1 expression in peripheral blood mononuclear cells at low concentrations than unmodified Lutein.