CYBERMED LIFE - ORGANIC  & NATURAL LIVING

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Oxidative Stress

Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Disturbances in the normal redox state of cells can cause toxic effects through the production of peroxides and free radicals that damage all components of the cell, including proteins, lipids, and DNA. Oxidative stress from oxidative metabolism causes base damage, as well as strand breaks in DNA. Base damage is mostly indirect and caused by reactive oxygen species (ROS) generated, e.g. O2 (superoxide radical), OH (hydroxyl radical) and H2O2 (hydrogen peroxide). Further, some reactive oxidative species act as cellular messengers in redox signaling. Thus, oxidative stress can cause disruptions in normal mechanisms of cellular signaling.

In humans, oxidative stress is thought to be involved in the development of ADHD, cancer, Parkinson's disease, Lafora disease, Alzheimer's disease, atherosclerosis, heart failure, myocardial infarction, fragile X syndrome, sickle-cell disease, lichen planus, vitiligo, autism, infection, chronic fatigue syndrome, and depression and seems to be characteristic of individuals with Asperger syndrome. However, reactive oxygen species can be beneficial, as they are used by the immune system as a way to attack and kill pathogens. Short-term oxidative stress may also be important in prevention of aging by induction of a process named mitohormesis.

  • Antioxidant,α-amylase and α-glucosidase activity of various solvent fractions of I. obliquus and the preventive role of active fraction against HOinduced damage in hepatic L02 cells as fungisome.

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    Abstract Title:

    Antioxidant,α-amylase and α-glucosidase activity of various solvent fractions of I. obliquus and the preventive role of active fraction against HOinduced damage in hepatic L02 cells as fungisome.

    Abstract Source:

    J Food Sci. 2020 Apr ;85(4):1060-1069. Epub 2020 Mar 9. PMID: 32147838

    Abstract Author(s):

    Xudong Gao, Ramesh Kumar Santhanam, Zihan Xue, Yanan Jia, Yajie Wang, Yangpeng Lu, Muenduen Phisalaphong, Haixia Chen

    Article Affiliation:

    Xudong Gao

    Abstract:

    Inonotus obliquus is a traditional mushroom well known for its therapeutic value. In this study, various solvent fractions of I. obliquus were preliminarily screened for their antioxidant,α-amylase and α-glucosidase inhibition properties. To improve the drug delivery, the active fraction (ethyl acetate fraction) of I. obliquus was synthesized into fungisome (ethyl acetate phophotidyl choline complex, EAPC) and its physical parameters were assessed using Fourier transform infrared spectroscopy (FTIR), High performance liquid chromatography (HPLC), Scanning electron microscope (SEM), and ς potential analysis. Then normal human hepatic L02 cells was used to evaluate the cytotoxicity of EAPC. The results showed that EA fraction possesses significant free radical scavenging, α-amylase and α-glucosidase inhibition properties. FTIR, SEM, and HPLC analysis confirmed the fungisome formation. The particle size of EAPC was 102.80 ± 0.42 nm and the ς potential was -54.30 ± 0.61 mV. The percentage of drug entrapment efficiency was 97.13% and the drug release rates of EAPC in simulated gastric fluid and simulated intestinal fluid were 75.04 ± 0.29% and 93.03 ± 0.36%, respectively. EAPC was nontoxic to L02 cells, however it could selectively fight against the HOinduced oxidative damage in L02 cells. This is the first study to provide scientific information to utilize the active fraction of I. obliquus as fungisome. PRACTICAL APPLICATIONS: Inonotus obliquus (IO) is a traditional medicinal fungus. The extracts of IO have obvious antioxidant and hypoglycemic activities. Ethyl acetate (EA) fraction of IO was encapsulated in liposomes to form EAPC. EAPC has a sustained-release effect. It has nontoxic to L02 cells and could protect L02 cells from oxidative damage caused by hydrogen peroxide. This study could provide new ideas for the treatment of diabetes.

  • Antioxidative and antiviral properties of flowering cherry fruits (Prunus serrulata L. var. spontanea).

    Abstract Title:

    Antioxidative and antiviral properties of flowering cherry fruits (Prunus serrulata L. var. spontanea).

    Abstract Source:

    Am J Chin Med. 2010;38(5):937-48. PMID: 20821824

    Abstract Author(s):

    Hong-Sun Yook, Kyoung-Hee Kim, Jung-Eun Park, Hyun-Jin Shin

    Article Affiliation:

    Department of Food and Nutrition, Chungnam National University, Daejeon, 305-764, Korea.

    Abstract:

    The phenolic compounds of many fruits have been known to be efficient cellular protective antioxidants. In this study, antioxidative and antiviral properties of flowering cherry cultivars (Prunus yedoensis, Prunus sargentii, Prunus lannesiana, and Prunus cerasus) in Korea were investigated. The antioxidant property was assayed for specific activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) hydroxy radical scavenging activity, reducing power capacity, and superoxide dismutase (SOD) like activity. In addition, antiviral activity was determined by inhibition studies on the infection cycle of porcine epidemic diarrhea virus (PEDV), measured as minimum concentration of cherry extracts that inhibited 50% of cytopathic effect (CPE) on PEDV. Our results show that the four varieties of cherries contain substantially high antioxidants and antiviral activities. In particular, P. cerasus contains higher antioxidants and antiviral activities as well as polyphenolic content than other varieties. Our data indicate that Korean native cherry cultivars could be beneficial supplements of dietary antioxidants and natural antiviral agents.

  • Antioxidative and antiviral properties of flowering cherry fruits (Prunus serrulata L. var. spontanea).

    Abstract Title:

    Antioxidative and antiviral properties of flowering cherry fruits (Prunus serrulata L. var. spontanea).

    Abstract Source:

    Am J Chin Med. 2010;38(5):937-48. PMID: 20821824

    Abstract Author(s):

    Hong-Sun Yook, Kyoung-Hee Kim, Jung-Eun Park, Hyun-Jin Shin

    Article Affiliation:

    Department of Food and Nutrition, Chungnam National University, Daejeon, 305-764, Korea.

    Abstract:

    The phenolic compounds of many fruits have been known to be efficient cellular protective antioxidants. In this study, antioxidative and antiviral properties of flowering cherry cultivars (Prunus yedoensis, Prunus sargentii, Prunus lannesiana, and Prunus cerasus) in Korea were investigated. The antioxidant property was assayed for specific activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) hydroxy radical scavenging activity, reducing power capacity, and superoxide dismutase (SOD) like activity. In addition, antiviral activity was determined by inhibition studies on the infection cycle of porcine epidemic diarrhea virus (PEDV), measured as minimum concentration of cherry extracts that inhibited 50% of cytopathic effect (CPE) on PEDV. Our results show that the four varieties of cherries contain substantially high antioxidants and antiviral activities. In particular, P. cerasus contains higher antioxidants and antiviral activities as well as polyphenolic content than other varieties. Our data indicate that Korean native cherry cultivars could be beneficial supplements of dietary antioxidants and natural antiviral agents.

  • Antioxidative and antiviral properties of flowering cherry fruits (Prunus serrulata L. var. spontanea).

    Abstract Title:

    Antioxidative and antiviral properties of flowering cherry fruits (Prunus serrulata L. var. spontanea).

    Abstract Source:

    Am J Chin Med. 2010;38(5):937-48. PMID: 20821824

    Abstract Author(s):

    Hong-Sun Yook, Kyoung-Hee Kim, Jung-Eun Park, Hyun-Jin Shin

    Article Affiliation:

    Department of Food and Nutrition, Chungnam National University, Daejeon, 305-764, Korea.

    Abstract:

    The phenolic compounds of many fruits have been known to be efficient cellular protective antioxidants. In this study, antioxidative and antiviral properties of flowering cherry cultivars (Prunus yedoensis, Prunus sargentii, Prunus lannesiana, and Prunus cerasus) in Korea were investigated. The antioxidant property was assayed for specific activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) hydroxy radical scavenging activity, reducing power capacity, and superoxide dismutase (SOD) like activity. In addition, antiviral activity was determined by inhibition studies on the infection cycle of porcine epidemic diarrhea virus (PEDV), measured as minimum concentration of cherry extracts that inhibited 50% of cytopathic effect (CPE) on PEDV. Our results show that the four varieties of cherries contain substantially high antioxidants and antiviral activities. In particular, P. cerasus contains higher antioxidants and antiviral activities as well as polyphenolic content than other varieties. Our data indicate that Korean native cherry cultivars could be beneficial supplements of dietary antioxidants and natural antiviral agents.

  • Antioxidative properties of crude polysaccharides from Inonotus obliquus. 📎

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    Abstract Title:

    Antioxidative properties of crude polysaccharides from Inonotus obliquus.

    Abstract Source:

    Int J Mol Sci. 2012 ;13(7):9194-206. Epub 2012 Jul 23. PMID: 22942760

    Abstract Author(s):

    Haibo Mu, Amin Zhang, Wuxia Zhang, Guoting Cui, Shunchun Wang, Jinyou Duan

    Article Affiliation:

    Haibo Mu

    Abstract:

    The mushroom Inonotus obliquus has been widely used as a folk medicine in Russia, Poland and most of the Baltic countries. In this study, water-soluble and alkali-soluble crude polysaccharides (IOW and IOA) were isolated from I. obliquus, and the carbohydrate-rich fractions IOW-1 and IOA-1 were obtained respectively after deproteination and depigmentation. Their contents, such as neutral carbohydrate, uronic acid and protein, were measured. Their antioxidant properties against chemicals-induced reactive species (ROS) including 1,1'-Diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide anion radical, as well as their protective effects on H(2)O(2)-induced PC12 cell death were investigated. Results showed that I. obliquus polysaccharides can scavenge all ROS tested above in a dose-dependent manner. IOA and its product IOA-1 could rescue PC12 cell viability from 38.6% to 79.8% and 83.0% at a concentration of 20μg/mL. Similarly, IOW and its product IOW-1 at the same dose, can also increase cell viability to 84.9% and 88.6% respectively. The antioxidative activities of water-soluble and alkali-soluble polysaccharide constituents from I. obliquus might contribute to diverse medicinal and nutritional valuesof this mushroom.

  • Antistress and antioxidant effects of virgin coconut oil in vivo📎

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    Abstract Title:

    Antistress and antioxidant effects of virgin coconut oil in vivo.

    Abstract Source:

    Exp Ther Med. 2015 Jan ;9(1):39-42. Epub 2014 Nov 3. PMID: 25452773

    Abstract Author(s):

    Swee Keong Yeap, Boon Kee Beh, Norlaily Mohd Ali, Hamidah Mohd Yusof, Wan Yong Ho, Soo Peng Koh, Noorjahan Banu Alitheen, Kamariah Long

    Article Affiliation:

    Swee Keong Yeap

    Abstract:

    Virgin coconut oil (VCO) has been consumed worldwide for various health-related reasons and some of its benefits have been scientifically evaluated. Medium-chain fatty acids were found to be a potential antidepressant functional food; however, this effect had not been evaluated in VCO, which is rich in polyphenols and medium-chain fatty acids. The aim of this study was to evaluate the antistress and antioxidant effects of VCO in vivo, using mice with stress-induced injury. The antistress effect of VCO (administered per os, at a dose of 10 ml/kg body weight) was evaluated using the forced swim test and chronic cold restraint stress models. VCO was able to reduce immobility time and restore oxidative stress in mice post-swim test. Furthermore, mice treated with VCO were found to exhibit higher levels of brain antioxidants, lower levels of brain 5-hydroxytryptamine and reduced weight of the adrenal glands. Consequently, the serum cholesterol, triglyceride, glucose and corticosterone levels were also lower in VCO-treated mice. These results suggest the potential value of VCO as an antistress functional oil.

  • Ascorbate deficiency and oxidative stress in the alveolar type II cell. 📎

    Abstract Title:

    Ascorbate deficiency and oxidative stress in the alveolar type II cell.

    Abstract Source:

    Am J Physiol Lung Cell Mol Physiol. 1997 Oct 1 ;273(4):L782-L788. PMID: 29585842

    Abstract Author(s):

    Lou Ann S Brown, Frank L Harris, Dean P Jones

    Article Affiliation:

    Lou Ann S Brown

    Abstract:

    The objective of this study was to determine the impact of limited ascorbate (Asc) availability on type II cell sensitivity to oxidant stress. Guinea pigs were fed diets with or without Asc for 18 days, and type II cells were isolated. Although lung Asc was decreased by 90% in deficient animals (scorbutic), type II cell Asc was decreased by 50%. Upon treatment with 250μM HO, the necrotic injury was twofold greater in scorbutic cells compared with control cells. With 100μM HOtreatment, apoptotic injury was twofold greater in scorbutic cells compared with control cells. Although there was less necrotic injury in cells exposed to 95% O, the scorbutic cells were more sensitive than control cells. Asc pretreatment protected against necrosis and apoptosis. The Asc analog isoascorbate provided partial protection and suggested that part of the protection was not chemical detoxification but was Asc specific. We conclude that limited Asc availability resulted in a functional type II cell but a cell more sensitive to oxidant-induced injury.

  • Ascorbic acid ameliorates seizures and brain damage in rats through inhibiting autophagy.

    Abstract Title:

    Ascorbic acid ameliorates seizures and brain damage in rats through inhibiting autophagy.

    Abstract Source:

    Brain Res. 2013 Oct 16 ;1535:115-23. Epub 2013 Aug 28. PMID: 23994218

    Abstract Author(s):

    Yan Dong, Shengjun Wang, Tongxia Zhang, Xiuhe Zhao, Xuewu Liu, Lili Cao, Zhaofu Chi

    Article Affiliation:

    Yan Dong

    Abstract:

    Oxidative stress is a mechanism of cell death induced by seizures. Antioxidant compounds have neuroprotective effects due to their ability to inhibit free radical production. Autophagy is a process in which cytoplasmic components such as organelles and proteins are delivered to the lysosomal compartment for degradation, and plays an essential role in the maintenance of cellular homeostasis. The activity of autophagy is enhanced during oxidative stress. The objectives of this work were first to study the inhibitory action of antioxidant ascorbic acid on behavioral changes and brain damage induced by high doses of pilocarpine, then to study the effect of ascorbic acid on oxidative stress (MDA and SOD were used to estimate oxidative stress) and activated autophagy (beclin 1 was used to estimate autophagy) induced by seizures, aiming to further clarify the mechanism of action of this antioxidant compound. In order to determinate neuroprotective effects, we studied the effects of ascorbic acid (500 mg/kg, i.p.) on the behavior and brain lesions observed after seizures induced by pilocarpine (340 mg/kg, i.p., P340 model) in rats. Ascorbic acid injections prior to pilocarpine suppressed behavioral seizure episodes by increasing the latency to the first myoclonic, clonic and tonic seizure and decreasing the percentage of incidence of clonic and tonic seizures as well as the mortality rate. These findings suggested that oxidative stress can be produced and autophagy is increased during brain damage induced by seizures. In the P340 model, ascorbic acid significantly decreased cerebral damage, reduced oxidative stress and inhibited autophagy by reducing de novo synthesis of beclin 1. Antioxidant compound can exert neuroprotective effects associated with inhibition of free radical production and autophagy. These results highlighted the promising therapeutic potential of ascorbic acid in treatment for seizures.

  • Ascorbic acid and beta-carotene reduce stress-induced oxidative organ damage in rats.

    Abstract Title:

    Ascorbic acid and beta-carotene reduce stress-induced oxidative organ damage in rats.

    Abstract Source:

    Biotech Histochem. 2016 Sep 14:1-10. Epub 2016 Sep 14. PMID: 27629436

    Abstract Author(s):

    M Esrefoglu, A Akinci, E Taslidere, H Elbe, A Cetin, B Ates

    Article Affiliation:

    M Esrefoglu

    Abstract:

    Antioxidants are potential therapeutic agents for reducing stress-induced organ damage. We investigated the effects of ascorbic acid andβ-carotene on oxidative stress-induced cerebral, cerebellar, cardiac and hepatic damage using microscopy and biochemistry. Male Wistar albino rats were divided into five groups: untreated control, stressed, stressed + saline, stressed + ascorbic acid and stressed + β-carotene. The rats in the stressed groups were subjected to starvation, immobilization and cold. The histopathological damage scores for the stressed and stressed + saline groups were higher than those of the control group for all organs examined. The histopathological damage scores and mean tissue malondialdehyde levels for thegroups treated with antioxidants were lower than those for the stressed and stressed + saline groups. Mean tissue superoxide dismutase activities for groups that received antioxidants were higher than those for the stressed + saline group for most organs evaluated. Ascorbic acid and β-carotene canreduce stress-induced organ damage by both inhibiting lipid oxidation and supporting the cellular antioxidant defense system.

  • Ascorbic acid attenuates acute pulmonary oxidative stress and inflammation caused by zinc oxide nanoparticles. 📎

    Abstract Title:

    Ascorbic acid attenuates acute pulmonary oxidative stress and inflammation caused by zinc oxide nanoparticles.

    Abstract Source:

    J Occup Health. 2015 ;57(2):118-25. Epub 2015 Aug 10. PMID: 25735507

    Abstract Author(s):

    Hiroko Fukui, Hitoshi Iwahashi, Shigehisa Endoh, Keiko Nishio, Yasukazu Yoshida, Yoshihisa Hagihara, Masanori Horie

    Article Affiliation:

    Hiroko Fukui

    Abstract:

    OBJECTIVES:It is known that inhalation of zinc oxide nanoparticles (ZnO NPs) induces acute pulmonary dysfunction, including oxidative stress, inflammation, and injury, but there are no reports on how to prevent these adverse effects. We have previously reported that the pulmonary symptoms caused by ZnO NPs were associated with oxidative stress; in the present study, we therefore investigated the use of ascorbic acid (AA), which is known as vitamin C, to prevent these toxic effects.

    METHODS:A ZnO NP dispersion was introduced into rat lungs by intratracheal injection, and thereafter a 1% aqueous AA solution was given as drinking water. Bronchoalveolar lavage fluid was collected at 1 day and 1 week after injection, and lactate dehydrogenase (LDH) activity, heme oxygenase-1 (HO-1), and interleukin-6 (IL-6) levels were measured. In addition, expression of the chemokine cytokine-induced neutrophil chemoattractants (CINCs), HO-1, and metallothionein-1 (MT-1) genes in the lungs were determined.

    RESULTS:Acute oxidative stress induced by ZnO NPs was suppressed by supplying AA. Increases in LDH activity and IL-6 concentration were also suppressed by AA, as was the expression of the CINC-1, CINC-3, and HO-1 genes.

    CONCLUSIONS:Oral intake of AA prevents acute pulmonary oxidative stress and inflammation caused by ZnO NPs. Intake of AA after unanticipated exposure to ZnO NPs is possibly the first effective treatment for the acute pulmonary dysfunction they cause.

  • Ascorbic acid prevents zinc oxide nanoparticle-induced intracellular oxidative stress and inflammatory responses.

    Abstract Title:

    Ascorbic acid prevents zinc oxide nanoparticle-induced intracellular oxidative stress and inflammatory responses.

    Abstract Source:

    Toxicol Ind Health. 2017 Jan 1:748233717707361. Epub 2017 Jan 1. PMID: 28854869

    Abstract Author(s):

    Hiroko Fukui, Hitoshi Iwahashi, Keiko Nishio, Yoshihisa Hagihara, Yasukazu Yoshida, Masanori Horie

    Article Affiliation:

    Hiroko Fukui

    Abstract:

    Exposure to zinc oxide nanoparticles (ZnO NPs) promotes acute pulmonary toxicity through oxidative stress and inflammation. Furthermore, dissolved zinc from ZnO NPs induces the formation of intracellular reactive oxygen species (ROS). We previously reported that supplemental ascorbic acid (AA) inhibits ZnO NP-induced acute pulmonary toxicity in a rat model; however, the mechanism of this action remains unclear. Therefore, we investigated the effects of AA on ZnO NP-induced cytotoxicity in human lung carcinoma A549 cells. AA was found to suppress intracellular production of ROS, and thus reduce the subsequent inflammation of ZnO NPs. However, intracellular Zn(2+) concentrations were higher in AA-treated cells than in AA-untreated cells. AA was found to react with Zn(2+) but not with the ZnO NPs themselves. These results suggest the possibility that AA-chelated extracellular Zn(2+) and the Zn-AA complex was readily taken up into cell. Even if the intracellular Zn(2+) level was high, cytotoxicity might be reduced because the Zn-AA complex was stable. Co-treatment of AA to A549 inhibited ROS production and subsequent intracellular inflammatory responses. These results are consistent with those previously reported from an in vivo model. Thus, two possibilities can be considered about the cytotoxicity-reducing the effect of AA: antioxidant efficacy and chelating effect.

  • Ascorbic acid provides protection for human chondrocytes against oxidative stress. 📎

    Abstract Title:

    Ascorbic acid provides protection for human chondrocytes against oxidative stress.

    Abstract Source:

    Mol Med Rep. 2015 Aug 20. Epub 2015 Aug 20. PMID: 26300283

    Abstract Author(s):

    Zhiqiang Chang, Lifeng Huo, Pengfei Li, Yimin Wu, Pei Zhang

    Article Affiliation:

    Zhiqiang Chang

    Abstract:

    Oxidative stress is considered to be an important cause of dysfunction in chondrocytes and articular cartilage degradation, which leads to the pathogenesis of osteoarthritis (OA) and cartilage aging. The present study aimed to assess the effects of the widely applied antioxidant, ascorbic acid (AA), on human chondrocytes against hydrogen peroxide (H2O2) in vitro. Using annexin V‑fluorescein isothiocyanate, 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyl tetrazolium bromide and senescence‑associated β‑galactosidase assays, the present study identified that AA reduced apoptosis, reduced the loss of viability and markedly decreased H2O2‑mediated senescence in cells treated with H2O2. Furthermore, AA not only stimulated the expression levels of collagens and proteoglycans, but also inhibited the differentiation of chondrocytes under conditions of oxidative stress. In addition, reverse transcription‑quantitative polymerase chain reaction and western blotting demonstrated that AA decreased the activity of nrf2, NF‑κB, AP1 and matrix metalloproteinase‑3, which is stimulated by H2O2. In conclusion, AA efficiently protected human chondrocytes against damage induced by H2O2 by regulating multiple regulatory pathways.

  • Ascorbic acid supplementation improves skeletal muscle oxidative stress and insulin sensitivity in people with type 2 diabetes: Findings of a randomized controlled study.

    Abstract Title:

    Ascorbic acid supplementation improves skeletal muscle oxidative stress and insulin sensitivity in people with type 2 diabetes: Findings of a randomized controlled study.

    Abstract Source:

    Free Radic Biol Med. 2016 Jan 13. Epub 2016 Jan 13. PMID: 26774673

    Abstract Author(s):

    Shaun A Mason, Paul A Della Gatta, Rod J Snow, Aaron P Russell, Glenn D Wadley

    Article Affiliation:

    Shaun A Mason

    Abstract:

    AIM/HYPOTHESIS:Skeletal muscle insulin resistance and oxidative stress are characteristic metabolic disturbances in people with type 2 diabetes. Studies in insulin resistant rodents show an improvement in skeletal muscle insulin sensitivity and oxidative stress following antioxidant supplementation. We therefore investigated the potential ameliorative effects of antioxidant ascorbic acid (AA) supplementation on skeletal muscle insulin sensitivity and oxidative stress in people with type 2 diabetes.

    METHODS:Participants with stable glucose control commenced a randomized cross-over study involving four months of AA (2×500mg/day) or placebo supplementation. Insulin sensitivity was assessed using a hyperinsulinaemic, euglycaemic clamp coupled with infusion of 6,6-D2 glucose. Muscle biopsies were measured for AA concentration and oxidative stress markers that included basal measures (2',7'-dichlorofluorescin [DCFH] oxidation, ratio of reduced-to-oxidized glutathione [GSH/GSSG] and F2-Isoprostanes) and insulin-stimulated measures (DCFH oxidation). Antioxidant concentrations, citrate synthase activity and protein abundances of sodium-dependent vitamin C transporter 2 (SVCT2), total Akt and phosphorylated Akt (ser473) were also measured in muscle samples.

    RESULTS:AA supplementation significantly increased insulin-mediated glucose disposal (delta rate of glucose disappearance;∆Rd) (p=0.009), peripheral insulin-sensitivity index (p=0.046), skeletal muscle AA concentration (p=0.017) and muscle SVCT2 protein expression (p=0.008); but significantly decreased skeletal muscle DCFH oxidation during hyperinsulinaemia (p=0.007) when compared with placebo. Total superoxide dismutase activity was also lower following AA supplementation when compared with placebo (p=0.006). Basal oxidative stress markers, citrate synthase activity, endogenous glucose production, HbA1C and muscle Akt expression were not significantly altered by AA supplementation.

    CONCLUSIONS/INTERPRETATION:In summary, oral AA supplementation ameliorates skeletal muscle oxidative stress during hyperinsulinaemia and improves insulin-mediated glucose disposal in people with type 2 diabetes. Findings implicate AA supplementation as a potentially inexpensive, convenient, and effective adjunct therapy in the treatment of insulin resistance in people with type 2 diabetes.

  • Ascorbic acid synergistically potentiates phloxine b-induced photocytotoxicity in human acute promyelocytic leukemia cells.

    Abstract Title:

    Ascorbic acid synergistically potentiates phloxine b-induced photocytotoxicity in human acute promyelocytic leukemia cells.

    Abstract Source:

    J Biochem Mol Toxicol. 2014 Apr ;28(4):167-73. Epub 2014 Jan 31. PMID: 24488945

    Abstract Author(s):

    Hang Qi, Qian Wu, Naomi Abe, Shunya Saiki, Beiwei Zhu, Yoshiyuki Murata, Yoshimasa Nakamura

    Article Affiliation:

    Hang Qi

    Abstract:

    Ascorbic acid (AsA) is known as an antioxidant but concomitantly possesses a pro-oxidant property. Because the impact of AsA on photodynamic therapy response is unclear, we investigated the effect of AsA on photocytotoxicity induced by phloxine B in human acute promyelocytic leukemia HL-60 cells. AsA synergistically enhanced phloxine B-induced photocytotoxic effects, including inhibition of cell proliferation, DNA ladder formation, and caspase-3 activation, whereas AsA itself showed no photocytotoxicity. AsA also enhanced the consumption of the reduced glutathione level compared with the cells treated with phloxine B alone under the light condition. Combination of AsA with phloxine B under the light condition enhanced the phosphorylation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase (MAPK). These effects were completely cancelled by catalase. These results suggest that AsA synergistically enhances phloxine B-induced photocytotoxicity, possibly through the extracellular oxidative stress-dependent MAPK pathway activation.

  • Association between prenatal exposure to metals and neonatal morbidity.

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    Abstract Title:

    Association between prenatal exposure to metals and neonatal morbidity.

    Abstract Source:

    J Toxicol Environ Health A. 2014 ;77(21):1281-4. PMID: 25268554

    Abstract Author(s):

    Isabella Karakis, Batia Sarov, Daniella Landau, Esther Manor, Maayan Yitshak-Sade, Michal Rotenberg, Reli Hershkovitz, Itamar Grotto, Elena Gurevich, Lena Novack

    Article Affiliation:

    Isabella Karakis

    Abstract:

    An association between prenatal exposure to (semi-)metals and of neonatal morbidity was assessed by introducing an oxidative stress as a possible intermediate step. An oxidative stress was measured by cell proliferation (CP) ratio in umbilical cord blood cells. Urine samples of 18 out of 58 enrolled women (31%) were positive for (semi-)metals; 25.9% of women were positive for aluminum (Al). The CP ratio was higher (1) in subjects with Al, (2) in mothers to newborns diagnosed as small-for-gestational age (p value = .052), (3) neonates that weighed less (p value = .079), and (4) in women who experienced repeated abortions (p value = .049). Our findings suggest the possibility of metal-induced oxidative stress.

  • Association of leukocyte telomere length with oxidative stress in yoga practitioners. 📎

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    Abstract Title:

    Association of leukocyte telomere length with oxidative stress in yoga practitioners.

    Abstract Source:

    J Clin Diagn Res. 2015 Mar ;9(3):CC01-3. Epub 2015 Mar 1. PMID: 25954614

    Abstract Author(s):

    Bandi Hari Krishna, Gorantla Shravya Keerthi, Chintala Kiran Kumar, Natham Mallikarjuna Reddy

    Article Affiliation:

    Bandi Hari Krishna

    Abstract:

    OBJECTIVE:Yoga is a mind-body modulation technique that has been shown to have beneficial effects on various diseases related to various systems in the body. However, the molecular basis of mechanism of action is not clear. Hence, this study was designed to study the leukocyte telomere biology and its relation with homocysteine and oxidative stress in yoga practitioners.

    MATERIALS AND METHODS:This is a prospective case-control study involving Yoga practitioners aged 30-40 y with minimum of two years yoga practice (Yoga group) and age, gender and body mass index matched sedentary healthy general population with no medical problems (Control group). Leukocyte telomere length (LTL) was measured by using quantitative PCR (qPCR), fasting plasma homocysteine was measured by a rapid high-performance liquid chromatography assay and the oxidative stress was assessed with total antioxidant status (TAOS), malondialdehyde (MDA) measured by calorimetry.

    RESULTS:The LTL was shorter in control group than in yoga group (p<0.001). The TAOS was more in yoga group when compared to control group (p=0.008), MDA and homocysteine was high in control group when compared to Yoga group (p<0.001). Further, the LTL was positively correlated with TAOS (r=0.841, p<0.001) and negatively correlated with MDA (r=-0.931, p<0.001) and Homocysteine (r=-0.756, p<0.001).

    CONCLUSION:The LTL is well-preserved in people who practice Yoga regularly with lower systemic oxidative stress compared to those who have a relatively sedentary lifestyle despite lack of any medical disorders. The habitual yoga practice seems to inhibit replicative cellular senescence.

  • Astaxanthin and peridinin inhibit oxidative damage in Fe(2+)-loaded liposomes: scavenging oxyradicals or changing membrane permeability?

    Abstract Title:

    Astaxanthin and peridinin inhibit oxidative damage in Fe(2+)-loaded liposomes: scavenging oxyradicals or changing membrane permeability?

    Abstract Source:

    Biochem Biophys Res Commun. 2001 Oct 19;288(1):225-32. PMID: 11594777

    Abstract Author(s):

    M P Barros, E Pinto, P Colepicolo, M Pedersén

    Article Affiliation:

    Department of Botany, Stockholm University, SE-10691 Stockholm, Sweden. This email address is being protected from spambots. You need JavaScript enabled to view it.

    Abstract:

    Astaxanthin and peridinin, two typical carotenoids of marine microalgae, and lycopene were incorporated in phosphatidylcholine multilamellar liposomes and tested as inhibitors of lipid oxidation. Contrarily to peridinin results, astaxanthin strongly reduced lipid damage when the lipoperoxidation promoters-H(2)O(2), tert-butyl hydroperoxide (t-ButOOH) or ascorbate-and Fe(2+):EDTA were added simultaneously to the liposomes. In order to check if the antioxidant activity of carotenoids was also related to their effect on membrane permeability, the peroxidation processes were initiated by adding the promoters to Fe(2+)-loaded liposomes (encapsulated in the inner aqueous solution). Despite that the rigidifying effect of carotenoids in membranes was not directly measured here, peridinin probably has decreased membrane permeability to initiators (t-ButOOH>ascorbate>H(2)O(2)) since its incorporation limited oxidative damage on iron-liposomes. On the other hand, the antioxidant activity of astaxanthin in iron-containing vesicles might be derived from its known rigidifying effect and the inherent scavenging ability.

  • Attenuation of blood pressure in spontaneously hypertensive rats by acupuncture was associated with reduction oxidative stress and improvement from endothelial dysfunction.

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    Abstract Title:

    Attenuation of blood pressure in spontaneously hypertensive rats by acupuncture was associated with reduction oxidative stress and improvement from endothelial dysfunction.

    Abstract Source:

    Chin Med. 2016 ;11(1):38. Epub 2016 Aug 30. PMID: 27582785

    Abstract Author(s):

    Sin Bond Leung, Hongwei Zhang, Chi Wai Lau, Zhi-Xiu Lin

    Article Affiliation:

    Sin Bond Leung

    Abstract:

    BACKGROUND:Hypertension can be treated effectively by acupuncture; however, the association between acupuncture and endothelial function remains unknown. This study aimed to investigate the effects of acupuncture on endothelial dysfunction and oxidative stress-related parameters in spontaneously hypertensive animals.

    METHODS:Eighteen-week-old Wistar-Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) were arbitrarily divided into four groups: WKY control (n = 8), SHR control (n = 8), SHR sham-acupuncture (n = 8) and SHR acupuncture (n = 8). The SHR acupuncture group had electroacupuncture for 6 consecutive weeks on acupoints ST36 and LR3. Blood pressure was monitored during the treatment period, and animals were euthanized at the 6th week. Aortas were harvested for determination of angiotensin II levels, NADPH oxidase activity and nitrate/nitrite levels. The level of reactive oxygen species (ROS) was determined by dihydroethidium (DHE) imaging, and functional studies were performed to assess vascular reactivity. Endothelial nitric oxidesynthase was measured by Western blot assay.

    RESULTS:Blood pressure at the end of treatment was significantly lower in the SHR acupuncture group (185.0 ± 5.6 mmHg) compared with the SHR sham-acupuncture and the SHR control groups (201.0 ± 5.4 and 197.4 ± 5.9 mmHg, respectively; P < 0.001). Serum angiotensin II level in the SHR control group was significantly higher than in the WKY control group (P < 0.001), while it was significantly attenuated by acupuncture treatment (P = 0.023). DHE staining showed that ROS level was reduced in the aortas (P = 0.0017) and carotid arteries (P = 0.039) of acupuncture-treated SHRs. Biochemical assays showed that acupuncture inhibited the NADPH oxidase activity (P = 0.022) and enhanced antioxidant capacity (P = 0.0039). In functional studies, endothelium-dependent relaxation of aortic rings (P = 0.018) and carotid arteries (P = 0.022) in response to acetylcholine was improved in the SHR acupuncture group. Aortas of SHRs receiving acupuncture also expressed an elevated level of eNOS (P > 0.001) and p-eNOS (P = 0.012) and a reduced nitrotyrosine level (P = 0.0012). The nitrate/nitrite level in aortic tissue was also attenuated after acupuncture (P = 0.0018).

    CONCLUSION:The effects of acupuncture in treating hypertension were associated with reduced oxidative stress, increased nitric oxide bioavailability and endothelial function in SHRs.

  • Attenuation of blood pressure in spontaneously hypertensive rats by acupuncture was associated with reduction oxidative stress and improvement from endothelial dysfunction📎

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    Abstract Title:

    Attenuation of blood pressure in spontaneously hypertensive rats by acupuncture was associated with reduction oxidative stress and improvement from endothelial dysfunction.

    Abstract Source:

    Chin Med. 2016 ;11(1):38. Epub 2016 Aug 30. PMID: 27582785

    Abstract Author(s):

    Sin Bond Leung, Hongwei Zhang, Chi Wai Lau, Zhi-Xiu Lin

    Article Affiliation:

    Sin Bond Leung

    Abstract:

    BACKGROUND:Hypertension can be treated effectively by acupuncture; however, the association between acupuncture and endothelial function remains unknown. This study aimed to investigate the effects of acupuncture on endothelial dysfunction and oxidative stress-related parameters in spontaneously hypertensive animals.

    METHODS:Eighteen-week-old Wistar-Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) were arbitrarily divided into four groups: WKY control (n = 8), SHR control (n = 8), SHR sham-acupuncture (n = 8) and SHR acupuncture (n = 8). The SHR acupuncture group had electroacupuncture for 6 consecutive weeks on acupoints ST36 and LR3. Blood pressure was monitored during the treatment period, and animals were euthanized at the 6th week. Aortas were harvested for determination of angiotensin II levels, NADPH oxidase activity and nitrate/nitrite levels. The level of reactive oxygen species (ROS) was determined by dihydroethidium (DHE) imaging, and functional studies were performed to assess vascular reactivity. Endothelial nitric oxidesynthase was measured by Western blot assay.

    RESULTS:Blood pressure at the end of treatment was significantly lower in the SHR acupuncture group (185.0 ± 5.6 mmHg) compared with the SHR sham-acupuncture and the SHR control groups (201.0 ± 5.4 and 197.4 ± 5.9 mmHg, respectively; P < 0.001). Serum angiotensin II level in the SHR control group was significantly higher than in the WKY control group (P < 0.001), while it was significantly attenuated by acupuncture treatment (P = 0.023). DHE staining showed that ROS level was reduced in the aortas (P = 0.0017) and carotid arteries (P = 0.039) of acupuncture-treated SHRs. Biochemical assays showed that acupuncture inhibited the NADPH oxidase activity (P = 0.022) and enhanced antioxidant capacity (P = 0.0039). In functional studies, endothelium-dependent relaxation of aortic rings (P = 0.018) and carotid arteries (P = 0.022) in response to acetylcholine was improved in the SHR acupuncture group. Aortas of SHRs receiving acupuncture also expressed an elevated level of eNOS (P > 0.001) and p-eNOS (P = 0.012) and a reduced nitrotyrosine level (P = 0.0012). The nitrate/nitrite level in aortic tissue was also attenuated after acupuncture (P = 0.0018).

    CONCLUSION:The effects of acupuncture in treating hypertension were associated with reduced oxidative stress, increased nitric oxide bioavailability and endothelial function in SHRs.

  • Attenuation of oxidative stress-induced changes in thalassemic erythrocytes by vitamin E📎

    Abstract Title:

    Attenuation of oxidative stress-induced changes in thalassemic erythrocytes by vitamin E.

    Abstract Source:

    Pol J Pharmacol. 2004 Jan-Feb;56(1):85-96. PMID: 15047982

    Abstract Author(s):

    Nandita Das, Tapasi Das Chowdhury, Aindrila Chattopadhyay, Asoke G Datta

    Article Affiliation:

    Department of Life Science and Biotechnology, Jadavpur University, Kolkata-700 032, India.

    Abstract:

    The oxidative stress status of the transfusion-dependent Ebeta- and beta-thalassemia patients were studied before and after treatment with vitamin E for a period of four weeks. The level of cellular vitamin antioxidants viz. ascorbic acid and vitamin E in the thalassemia patients were found to be considerably lower compared to normal subjects. The activities of enzymatic antioxidants viz. catalase, glutathione peroxidase and glutathione reductase were found to be drastically reduced in untreated Ebeta- and beta-thalassemic patients when compared to normal subjects. However, the activity of superoxide dis-mutase was found to be increased in both types of untreated thalassemic patients when compared to normal individuals. An increase in superoxide dismutase and a decrease in catalase activity reflects the presence of a severe oxidative stress situation in the erythrocytes of the untreated transfusion dependent Ebeta- and beta-thalassemia patients. Changes in erythrocyte membrane protein pattern in untreated Ebeta- and beta-thalassemia patients when compared to normal erythrocyte further confirm the presence of continued oxidative stress in the ailing thalassemic erythrocytes. All these changes in the antioxidant status as well as the changes in the erythrocyte membrane proteins are ameliorated to considerable extent when the transfusion-dependent Ebeta- and beta-thalassemia patients were treated with vitamin E at a dose of 10 mg/kg/day for a period of four weeks. The patients during the treatment period did not exhibit any side effects and gained in body weight indicating a healthy status. The present study reveals that the lipophilic antioxidant vitamin E could be useful in the management of transfusion-dependant Ebeta- and beta-thalassemia patients.