Introduction: In Malaysia, Heterotrigona itama sp. (stingless bee) industries start to grow rapidly since 2015 but the study on its health benefit is still lacking. This study was aimed to analyse and compare the sugar content, minerals and antioxidant properties of stingless bee honey collected from forest and suburban area in Malaysia. Methods: Sugar content was determined by HPLC, minerals and heavy metals was determined by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) and Atomic Absorption Spectrometer (AAS), total phenolic content (TPC) and total flavonoid content (TFC) by Folin-Ciocalteu and aluminium chloride colorimetry method, respectively. For determining the antioxidant activity of the samples, 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH), 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assay were used. Results: Fructose, glucose and sucrose are found in all samples in range of 16.03-33.13 g/100g, 8.63-20.72 g/100g and 2.68-34.04 g/100g, respectively. Potassium and sodium were major minerals in all stingless bee honey with an average of 622.36 and 496.01 mg/kg, respectively. Sample from the forest (Sibu, F2) has the highest TPC and TFC with value 520.663±8.119µg GAE/g and 443.25±18.194µg RE/g, respectively. The higher antioxidant activities (DPPH, ABTS, FRAP) also found in samples collected from the forest (F2) with 602.15±12.7 µg TE/g, 575.18±9.38 µg TE/g and 641.36±42.11µg TE/g, respectively. Conclusion: All stingless bee honey studied shown a significant amount of important minerals and antioxidant properties with samples from forest clearly shown significantly higher TPC and TFC as well as the antioxidant activity than samples collected from the suburban area.
Antioxidant

Introduction: Archidendron bubalinum is an underutilised plant with numerous antioxidant properties and has a great potential to inhibit enzymes linked with diabetes and obesity. Food irradiation is an advanced technology to prolong the lifespan of plant, prevent physical spoilage and eradicate food borne disease. Present study was aimed to determine the total antioxidant activity, enzymatic inhibition against alpha-amylase, alpha-glucosidase and pancreatic lipase and the toxicity levels of non-irradiated and irradiated (3, 6, 9 & 12 kGy) hot aqueous extract of A. bubalinum. Methods: The antioxidant ability of the extract was determined by total phenolic content (TPC), total flavanoid content (TFC), Diphenyl-1-Picrylhydrazyl (DPPH), β-carotene assay and ferric reducing antioxidant potential (FRAP) assay. The inhibitory activities were evaluated using α-amylase, α-glucosidase, and pancreatic lipase inhibition assay. The toxicity levels of A. bubalinum extract were determined using Brine shrimp and Zebra-fish assays. Results: Results showed that irradiated A. bubalinum at 12 kGy demonstrated the highest TFC (448.99 ± 5.02 mg GAE/g), FRAP (2.55 ± 0.40 mmol Fe2+/g) and β-carotene bleaching activity (79.49%). Whereas, non-irradiated A. bubalinum samples expressed the highest TPC (2517.07 ± 15.81 mg GAE/g) and exhibited the lowest IC50 values of α-amylase (31.99 ± 3.15 μg/ml), α-glucosidase (23.40 ± 0.69μg/ml) and pancreatic lipase (32.81 ± 7.96 μg/ml) activity. The toxicity assays also showed no significant different between irradiated and non-irradiated samples. Conclusion: The study suggests that gamma irradiation has the prospective future to increase antioxidant properties and maintaining the enzyme inhibitory activities to preserve the sample of A. bubalinum for commercial purposes
Antioxidant

Activity of some erythrocyte antioxidant enzymes SOD, GPx and GR and total plasma antioxidant status were investigated on 58 workers who were working an a petroleum company. The results showed that there are negative correlation between blood lead level with activity of GPx and GR enzymes (r= -0.5724 and -0.4341, respectively). There was a slight decrease in total plasma antioxidant status of groups with high blood lead level, but it is insignificant.
Antioxidant ; Enzymology ; Erythrocytes

The cytoprotective enzyme heme oxygenase-1 (HO-1) influences endothelial cell survival, proliferation, inflammatory response, and angiogenesis in response to various angiogenic stimuli. In this study, we investigate the involvement of HO-1 in the angiogenic activity of orexin-A. We showed that orexin-A stimulates expression and activity of HO-1 in human umbilical vein endothelial cells (HUVECs). Furthermore, we showed that inhibition of HO-1 by tin (Sn) protoporphryin-IX (SnPP) reduced orexin-A-induced angiogenesis in vivo and ex vivo. Orexin-A-stimulated endothelial tube formation and chemotactic activity were also blocked in SnPP-treated vascular endothelial cells. Orexin-A treatment increased the expression of nuclear factor erythroid-derived 2 related factor 2 (Nrf2), and antioxidant response element (ARE) luciferase activity, leading to induction of HO-1. Collectively, these findings indicate that HO-1 plays a role as an important mediator of orexin-A-induced angiogenesis, and provide new possibilities for therapeutic approaches in pathophysiological conditions associated with angiogenesis.
Antioxidant Response Elements ; Endothelial Cells* ; Heme Oxygenase-1* ; Human Umbilical Vein Endothelial Cells ; Luciferases ; Tin ; Orexins

Keratinocytes are constantly exposed to extracellular insults, such as ultraviolet B, toxic chemicals and mechanical stress, all of which can facilitate the aging of keratinocytes via the generation of intracellular reactive oxygen species (ROS). Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that plays a critical role in protecting keratinocytes against oxidants and xenobiotics by binding to the antioxidant response element (ARE), a cis-acting element existing in the promoter of most phase II cytoprotective genes. In the present study, we have attempted to find novel ethanol extract(s) of indigenous plants of Jeju island, Korea that can activate the Nrf2/ARE-dependent gene expression in human keratinocyte HaCaT cells. As a result, we identified that ethanol extract of Cirsium japonicum var. ussuriense Kitamura (ECJUK) elicited strong stimulatory effect on the ARE-dependent gene expression. Supporting this observation, we found that ECJUK induced the expression of Nrf2, hemoxygenase-1, and NAD(P)H:quinone oxidoreductase-1 and this event was correlated with Akt1 phosphorylation. We also found that ECJUK increased the intracellular reduced glutathione level and suppressed 12-O-tetradecanoylphorbol acetate-induced 8-hydroxyguanosine formation without affecting the overall viability. Collectively, our results provide evidence that ECJUK can protect against oxidative stress-mediated damages through the activation of Nrf2/ARE-dependent phase II cytoprotective gene expression.
Aging ; Antioxidant Response Elements* ; Cirsium* ; DNA Damage* ; DNA* ; Ethanol* ; Gene Expression ; Glutathione ; Humans* ; Keratinocytes* ; Korea ; Oxidants ; Phosphorylation ; Reactive Oxygen Species ; Stress, Mechanical ; Transcription Factors ; Xenobiotics

Our previous study demonstrated that methanolic extract of Chrysanthemum zawadskii Herbich var. latilobum Kitamura (Compositae) has the potential to induce detoxifying enzymes such as NAD(P)H:(quinone acceptor) oxidoreductase 1 (EC 1.6.99.2) (NQO1, QR) and glutathione S-transferase (GST). In this study we further fractionated methanolic extract of Chrysanthemum zawadskii and investigated the detoxifying enzyme-inducing potential of each fraction. The fraction (CZ-6) shown the highest QR-inducing activity was found to contain (+)-(3S,4S,5R,8S)-(E)-8-acetoxy-4-hydroxy-3-isovaleroyloxy-2-(hexa-2,4-diynyliden)-1,6-dioxaspiro [4,5] decane and increased QR enzyme activity in a dose-dependent manner. Furthermore, CZ-6 fraction caused a dose-dependent enhancement of luciferase activity in HepG2-C8 cells generated by stably transfecting antioxidant response element-luciferase gene construct, suggesting that it induces antioxidant/detoxifying enzymes through antioxidant response element (ARE)-mediated transcriptional activation of the relevant genes. Although CZ-6 fraction failed to induce hepatic QR in mice over the control, it restored QR activity suppressed by CCl4 treatment to the control level. Hepatic injury induced by CCl4 was also slightly protected by pretreatment with CZ-6. In conclusion, although CZ-6 fractionated from methanolic extract of Chrysanthemum zawadskii did not cause a significant QR induction in mice organs such as liver, kidney, and stomach, it showed protective effect from liver damage caused by CCl4.
Alkanes ; Animals ; Antioxidant Response Elements ; Carbon ; Carbon Tetrachloride ; Chrysanthemum ; Glutathione Transferase ; Kidney ; Liver ; Luciferases ; Methanol ; Mice ; NAD(P)H Dehydrogenase (Quinone) ; Stomach ; Transcriptional Activation

In the present study, we found that the natural compound arctigenin inhibited hydrogen peroxide-induced reactive oxygen species (ROS) production in rat primary astrocytes. Since hemeoxygenase-1 (HO-1) plays a critical role as an antioxidant defense factor in the brain, we examined the effect of arctigenin on HO-1 expression in rat primary astrocytes. We found that arctigenin increased HO-1 mRNA and protein levels. Arctigenin also increases the nuclear translocation and DNA binding of Nrf2/c-Jun to the antioxidant response element (ARE) on HO-1 promoter. In addition, arctigenin increased ARE-mediated transcriptional activities in rat primary astrocytes. Further mechanistic studies revealed that arctigenin increased the phosphorylation of AKT, a downstream substrate of phosphatidylinositol 3-kinase (PI3K). Treatment of cells with a PI3K-specific inhibitor, LY294002, suppressed the HO-1 expression, Nrf2 DNA binding and ARE-mediated transcriptional activities in arctigenin-treated astrocyte cells. The results collectively suggest that PI3K/AKT signaling pathway is at least partly involved in HO-1 expression by arctigenin via modulation of Nrf2/ARE axis in rat primary astrocytes.
Animals ; Antioxidant Response Elements ; Astrocytes* ; Axis, Cervical Vertebra ; Brain ; DNA ; Gene Expression* ; Hydrogen ; Phosphatidylinositol 3-Kinase ; Phosphorylation ; Rats* ; Reactive Oxygen Species ; RNA, Messenger

Minor ginsenosides Rh1 and Rg2 were isolated from Korean red ginseng and reported to have various biological effects on anti-inflammatory and anti-stress activities. However, the effects of Rh1 and Rg2 on antioxidant activity and their regulatory effects on the antioxidant enzymes have not been studied. Since oxidative stress is one of the major toxic inflammatory responses stimulated by lipopolysaccharides (LPS), the present study investigated the role of minor ginsenosides Rh1 and Rg2 on antioxidant effects in LPS-treated RAW 264.7 cells. In this study, we found that treatment with ginsenosides Rh1 and Rg2 strongly inhibited LPS-stimulated intracellular ROS production in cells. Luciferase assay showed that treatment with LPS reduced antioxidant response element (ARE) encoding the pARE-luc promoter activity, while ginsenosides inhibited the pARE-luc promoter activity. Moreover, ginsenosides Rh1 and Rg2 exhibited anti-oxidative activity in LPS-induced cells by upregulating antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase. Our results suggest that minor ginsenosides Rh1 and Rg2 may be potential bio-active compounds for antioxidative effects by inhibiting the generation of ROS in RAW 264.7 cells.
Antioxidant Response Elements ; Antioxidants ; Catalase ; Ginsenosides* ; Glutathione Peroxidase ; Lipopolysaccharides ; Luciferases ; Oxidative Stress* ; Panax ; RAW 264.7 Cells* ; Reactive Oxygen Species ; Superoxide Dismutase

Oxidative stress activates several intracellular signaling cascades that may have deleterious effects on neuronal cell survival. Thus, controlling oxidative stress has been suggested as an important strategy for prevention and/or treatment of neurodegenerative diseases. In this study, we found that ginsenoside Rh1 inhibited hydrogen peroxide-induced reactive oxygen species generation and subsequent cell death in rat primary astrocytes. Rh1 increased the expression of phase II antioxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1, superoxide dismutase-2, and catalase, that are under the control of Nrf2/ARE signaling pathways. Further mechanistic studies showed that Rh1 increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to the antioxidant response element (ARE), and increased the ARE-mediated transcription activities in rat primary astrocytes. Analysis of signaling pathways revealed that MAP kinases are important in HO-1 expression, and act by modulating ARE-mediated transcriptional activity. Therefore, the upregulation of antioxidant enzymes by Rh1 may provide preventive therapeutic potential for various neurodegenerative diseases that are associated with oxidative stress.
Animals ; Antioxidant Response Elements ; Astrocytes* ; Catalase ; Cell Death ; Cell Survival ; DNA ; Gene Expression* ; Heme Oxygenase-1 ; Hydrogen ; Neurodegenerative Diseases ; Neurons ; Oxidative Stress ; Phosphotransferases* ; Rats* ; Reactive Oxygen Species ; Superoxides ; Up-Regulation

BACKGROUND: NAD(P)H:quinone oxidoreductase-1 (NQO1) is a widely-distributed flavin adenine dinucleotide-dependent flavoprotein that promotes obligatory 2-electron reductions of quinones, quinoneimines, nitroaromatics, and azo dyes. This reduces quinone levels and thereby minimizes generation of excess reactive oxygen species (ROS) formed by redox cycling, and concurrent depletion of intracellular thiol pools. Ajoene is derived from crushed garlic. It is formed by a reaction involving two allicin molecules, and is composed of allyl sulfide and vinyl disulfide. Ajoene is present in two isomers, E- and Z-form. METHODS: Expression of antioxidant enzymes and nuclear factor E2-related factor-2 (Nrf2) was measured by Western blot analysis. NQO1 promoter activity was assessed by the luciferase reporter gene assay. ROS accumulation was monitored by using the fluorescence-generating probe 2′,7′-dichlorofluorescein diacetate. The intracellular glutathione levels were measured by using a commercially available kit. RESULTS: Z-ajoene significantly up-regulated the expression of representative antioxidant enzyme NQO1 in non-tumorigenic breast epithelial MCF-10A cells at non-toxic concentrations. Z-ajoene enhanced up-regulation and nuclear translocation of Nrf2, which plays a pivotal role in the induction of many genes encoding antioxidant enzymes and other cytoprotective proteins. Z-ajoene treatment also increased the activity of nqo1-promoter harboring antioxidant response element consensus sequences in MCF-10A cells. Silencing of Nrf2 by small interfering RNA abrogated ajoene-induced expression of NQO1. Z-ajoene activated extracellular signal-regulated kinase (ERK). Inhibition of ERK activation by U0126 abrogated ability of Z-ajoene to activate Nrf2 and to induce NQO1 expression. Intracellular ROS accumulation was observed after treatment with Z-ajoene, whereas the E-isoform was not effective. The inhibition of ROS by treatment with N-acetylcysteine, a radical scavenger, abrogated Z-ajoene-induced expression of NQO1 as well as activation of ERK and Nrf2, suggesting that Z-ajoene augments the Nrf2-dependent antioxidant defense via ROS generation and ERK activation. CONCLUSIONS: Z-ajoene induces NQO1 expression in MCF-10A cells through ROS-mediated activation of Nrf2.
Acetylcysteine ; Adenine ; Antioxidant Response Elements ; Azo Compounds ; Blotting, Western ; Breast ; Consensus Sequence ; Epithelial Cells ; Flavoproteins ; Garlic ; Genes, Reporter ; Glutathione ; Humans ; Luciferases ; NF-E2-Related Factor 2 ; Oxidation-Reduction ; Phosphotransferases ; Quinones ; Reactive Oxygen Species ; RNA, Small Interfering ; Up-Regulation