Syringic acid induces cancer cell death in the presence of Cu (II) ions via pro-oxidant activity

Objective: To investigate the effects of syringic acid on HEK 293 and HepG2 cells in the absence and presence of exogenous Cu (II) and Fe (II) ions. Methods: The antiproliferative effects of syringic acid on HEK 293 and HepG2 cells in the absence and presence of exogenous Cu (II) and Fe (II) ions were examined by MTT assay. Additionally, colony-forming, reactive oxidative species (ROS) generation, apoptosis induction, autophagy, mitochondrial membrane potential, and mitochondrial mass were investigated. Results: At 24 and 72 h, no significant differences were observed in the viability of HepG2 cells between the control and syringic acid + Fe (II) groups. However, exposure of HepG2 cells to syringic acid + Cu (II) for 72 h reduced the cell viability significantly. Furthermore, ROS formation, induction of apoptosis, and autophagic vacuoles were significantly increased in HepG2 cells without marked changes in mitochondrial membrane potential and mitochondrial mass. Moreover, syringic acid + Cu (II) reduced the plating efficiency and surviving fraction significantly. Conclusions: The combination of syringic acid with Cu (II) was toxic to cancer cells and showed pro-oxidant activity. In addition, this combination induced autophagy in cancer cells with less cytotoxic effects on normal cells, which is a potential candidate for the development of novel therapeutics towards cancer.

Role of redox iron towards an increase in mortality among patients: a systemic review and meta-analysis

An increase in biochemical concentrations of non-transferrin bound iron (NTBI) within the patients with an increase in serum iron concentration was evaluated with the following objectives: (a) Iron overloading diseases/conditions with free radicle form of ‘iron containing’ reactive oxygen species (ROS) and its imbalance mediated mortality, and (b) Intervention with iron containing drugs in context to increased redox iron concentration and treatment induced mortality. Literature search was done within Pubmed and cochrane review articles. The Redox iron levels are increased during dys-erythropoiesis and among transfusion recipient population and are responsive to iron-chelation therapy. Near expiry ‘stored blood units’ show a significant rise in the ROS level. Iron mediated ROS damage may be estimated by the serum antioxidant level, and show reduction in toxicity with high antioxidant, low pro-oxidant levels. Iron drug therapy causes a significant increase in NTBI and labile iron levels. Hospitalized patients on iron therapy however show a lower mortality rate. Serum ferritin is a mortality indicator among the high-dose iron therapy and transfusion dependent population. The cumulative difference of pre-chelation to post chelation ROS iron level was 0.97 (0.62; 1.32; N=261) among the transfusion dependent subjects and 2.89 (1.81–3.98; N=130) in the post iron therapy ‘iron ROS’ group. In conclusion, iron mediated mortality may not be mediated by redox iron among multi-transfused and iron overloaded patients.

Bacillus sp. SAB E-41-derived extract shows antiaging properties via ctt1-mediated oxidative stress tolerance response in yeast Schizosaccharomyces pombe

Objective: To analyze potential activation of oxidative stress tolerance systems by SAB E-41 bacterial extract in promoting the life span of yeast Schizosaccharomyces pombe. Methods: In vitro analysis was done to assess antioxidant activity of SAB E-41 bacterial extract. Antiaging property of the particular extract was then assayed through spot test and chronological life span assays. Furthermore, sty1 mitogen-activated protein kinase, pap1 transcriptional factor of oxidative stress response and its downstream genes, ctt1 were evaluated via real time PCR. The protein level of ctt1 was then observed via Western Blot analysis. In addition, accumulation of reactive oxygen species and mitochondrial activity were conducted to understand the effect of SAB E-41 upon oxidative stress response systems in vivo. Results: The IC

The role of carnosine on the oxidation reaction in vitro / 安徽医科大学学报

In this study, HRP or FeCl3were used as the catalysts in MTT, TMB and Mino reaction system, the effects of carnosine on the oxidation reaction were evaluated respectively. Indeed, carnosine was a pro-oxidant in luminol reaction, however an anti-oxidant in MTT assay. Once TMB was its substrate, carnosine was neutral in oxi-dation. Thus, it is supposed that the oxidative property of carnosine depends on the substrates.

Evaluation of prooxidant-antioxidant balance in in vitro fertilization-conceived mice / 대한생식의학회지

OBJECTIVE: Concerns about the safety of assisted reproductive technology (ART) have been raised, as some studies have shown elevated incidence rates of childhood cancer, asthma, allergies, and other diseases in ART-conceived babies. Findings regarding the health of ART-conceived babies are controversial. The present study was conducted to evaluate the prooxidant-antioxidant balance (PAB) in in vitro fertilization (IVF)-conceived mice in comparison to naturally conceived offspring. METHODS: Mice (6–8 weeks) were divided into two groups (IVF-conceived and naturally conceived) matched by sex, age, weight, and litter size. A 1-mL blood sample was taken and the sera were separated. The oxidant-antioxidant balance was evaluated using a fast and reliable PAB assay. The results were expressed as mean±standard deviation. RESULTS: The mean PAB values (HK units) in the IVF-conceived and naturally conceived groups were 59.70±22.30 and 54.70±18.22, respectively (p=0.82). CONCLUSION: Since free radicals contribute to several pathological conditions and antioxidants play an important protective role against oxidative stress, evaluating the oxidant-antioxidant balance is very important. Although the results of this study showed that the quality of the defense mechanism against free radicals was not significantly different between the IVF-conceived and naturally conceived mice, other parameters of metabolic dysfunction need to be measured.

Bacillus sp. SAB E-41-derived extract shows antiaging properties via ctt1-mediated oxidative stress tolerance response in yeast Schizosaccharomyces pombe

Objective: To analyze potential activation of oxidative stress tolerance systems by SAB E-41 bacterial extract in promoting the life span of yeast Schizosaccharomyces pombe. Methods: In vitro analysis was done to assess antioxidant activity of SAB E-41 bacterial extract. Antiaging property of the particular extract was then assayed through spot test and chronological life span assays. Furthermore, sty1 mitogen-activated protein kinase, pap1 transcriptional factor of oxidative stress response and its downstream genes, ctt1 were evaluated via real time PCR. The protein level of ctt1 was then observed via Western Blot analysis. In addition, accumulation of reactive oxygen species and mitochondrial activity were conducted to understand the effect of SAB E-41 upon oxidative stress response systems in vivo. Results: The IC50 values of corresponding extract for antioxidant (DPPH; ABTS) and antiglycation were 402.40, 358.13 and 683.55 μg/mL, respectively. In addition, SAB E-41 extract (750 μg/mL) exhibited antiaging properties, which could be attributed to significant up-regulation of oxidative stress response genes, sty1, pap1 and ctt1. Interestingly, SAB E-41 extract could enhance stress tolerance phenotype of Schizosaccharomyces pombe against H2O2-induced oxidative stress. These results were supported by increasing mitochondrial activity and reactive oxygen species intracellular levels. Conclusions: SAB E-41 extract could promote yeast life span likely via up-regulation of oxidative stress responses in yeast. Our results suggest that adaptive response via up-regulation of oxidative stress transcriptional factors, and its downstream gene, ctt1, as well as mitochondrial activity contributes in combating oxidative stress thus promoting yeast life span.

Evaluation of Advanced Oxidation Protein Products, Prooxidant-Antioxidant Balance, and Total Antioxidant Capacity in Untreated Vitiligo Patients

BACKGROUND: Vitiligo is a chronic, common disease of unknown etiology, and oxidative stress is suggested to have a role in its etiopathogenesis. OBJECTIVE: Advanced oxidation protein products (AOPPs), prooxidant-antioxidant balance (PAB), and ferric-reducing antioxidant power (FRAP) were evaluated regarding their role in the pathogenesis of vitiligo as well as their relationship with clinical presentation and disease severity, and these parameters were compared with those of healthy controls. METHODS: The study included 53 patients with vitiligo and 20 healthy volunteers as the control group. AOPP level, PAB, and FRAP were determined by colorimetric methods. RESULTS: PAB and FRAP level were significantly higher in patients with vitiligo than in healthy controls (p<0.001). The AOPP levels in vitiligo patients were not statistically significantly higher than those in healthy controls. The Vitiligo Area Scoring Index positively correlated with disease duration (r(s): 0.531, p<0.001). CONCLUSION: To the best of our knowledge, this is the first report of AOPP and PAB status in vitiligo. PAB may be used as an indicator for oxidative stress in the etiopathogenesis of vitiligo. Our results show that these parameters may play a major role in the melanocyte damage observed in vitiligo. Further studies are required to confirm the mechanisms underlying this effect.

Vitamin E Supplementation Improves Oxidant-antioxidant Balance in Chronic Renal Failure Patients Treated by Hemodialysis.

Aims: The purpose of this study was to evaluate the effect of vitamin E supplementation on oxidant-antioxidant balance in chronic renal failure patients treated by hemodialysis. Study Design: The study utilized a randomized experimental design. The experimental intervention consisted of vitamin E supplementation Place and Duration of Study: 40 patients on hemodialysis (M/W=22/18; 36±12 years) received nutritional councils based on the NKF K/DOQI (National Kidney Foundation- Kidney Disease Outcomes Quality Initiative) guidelines. Patients were randomized into 2 groups:one was used as control and the second group was treated by vitamin E supplementation (100mg/day=146IU/d) during 30 days. Methodology: Pro-oxidant status was assessed by thiobarbituric acid reactive substances, hydroperoxides and carbonyls analysis. Antioxidant defence was performed by the analysis of Superoxide dismutase, Catalase, Glutathione reductase activities and Vitamin E amounts. Results: At 30 days of supplementation, in treated patients compared to controls, levels of triacylglycerols and total cholesterol were unchanged. Hydroperoxides concentrations were decreased (p<0.001) while thiobarbituric acid reactive substances concentrations were unchanged. Carbonyls levels were decreased (p<0.001). High concentrations of vitamin E were noted in treated group (p<0.01). Similar superoxide dismutase activity was noted. However, an increase in vitamin E concentrations, catalase and glutathione reductase activities were observed in treated group (p<0.01). Conclusion: In conclusion, in hemodialysis patients, vitamin E supplementation was without effect on lipid profile. However, vitamin E exerts a protective effect on cardiovascular diseases by decreasing radical attack of biological molecules and increasing antioxidant defense.

Antioxidant and pro-oxidant activity of Vitamin C in oral environment.

Context: Antioxidant properties and Vitamin C. Background: Vitamin C is a naturally occurring organic compound and a potent antioxidant preventing oxidative damage to lipids and other macromolecules. It can also exhibit bimodal activity as a pro‑oxidant at a higher concentration. Vitamin C has a switch over role from being an antioxidant in physiologic conditions to a pro‑oxidant under pathologic conditions. A systematic review of this role would help to elucidate whether it is an antioxidant or a pro‑oxidant in the oral environment. Objective: To review studies reported in the literature elucidating the activity of Vitamin C and determine whether it is an antioxidant or a pro‑oxidant. Materials and Methods: Articles were searched in PubMed, MEDLINE using appropriate key words like “Vitamin C,” “antioxidant activity,” “pro‑oxidant activity,” “oral health” “oral disease.” Hand search of journals was also performed. Articles were reviewed and analyzed. Results: Search strategy reviewed 10 relevant articles which studied the dual role of Vitamin C. 65% of authors analyzed antioxidant action of ascorbic acid compared to 35% of the pro‑oxidant potential. Vitamin C acts as an antioxidant and a pro‑oxidant by a plethora of mechanisms. Factors determining its bimodal activity were studied, and the frequencies of their occurrence in the literature were depicted in percentage. Conclusion: The data validates the role of Vitamin C as an antioxidant under physiologic conditions exhibiting a cross over role as a pro‑oxidant in pathological conditions. Further studies are required to substantiate its pro‑oxidant activity to draw concrete conclusions.

L-Arginine attenuates oxidative stress condition during cardiomyopathy.

Increased production of oxygen free radicals and decreased oxidant capacity occur in coronary artery diseases (CAD). This pro-oxidant shift in intracellular redox state may induce cell death by either direct cell membrane damage by lipid peroxidation or apoptosis through activation of transcription factors. These changes occur not only in cardiomyocytes, but also in cardiac sympathetic nerves, which are very sensitive to oxidative damage. Patients with heart failure encounter reduced peripheral blood flow at rest, during exercise and in response to endothelium-dependent vasodilators. Current treatments of cardiomyopathy, a degenerative condition of the myocardium frequently associated with heart failure have done little to enhance patient survival. Decreased myocardial contractility and altered regulation of peripheral circulation along with oxidative conditions are important contributors to the symptoms and prognosis of the disease process. Nitric oxide formed from L-arginine (2-amino-5 guanidinovaleric acid) metabolism in endothelial cells contributes to regulation of blood flow under these conditions. L-Arginine is the precursor of nitric oxide, an endogenous messenger molecule involved in a variety of endothelium-mediated physiological effects in the vascular system. In the present study, we investigated the effect of oral administration of L-arginine (3 g/day) on the intracellular redox status of the patients of ischemic cardiomyopathy aged 45-60 yrs. The enzymatic and non-enzymatic antioxidant parameters like superoxide dismutase, catalase, total thiols (TSH) and ascorbic acid along with pro-oxidant parameters, such as xanthine oxidase, as well as index of oxidative stress as protein carbonyl content and malondialdehyde (a marker of lipid peroxidation) were investigated in the plasma and RBC lysate. L-Arginine (3 g/day) administration was found to improve the levels of these parameters in the patients and regulate the blood flow, as evident by the improved blood pressure of the patients. Thus, it is inferred that L-arginine attenuates the oxidative stress conditions along with maintaining the blood pressure rate of patients suffering from cardiomyopathy.

Synergistic effect of calcium stearate and photo treatment on the rate of biodegradation of low density polyethylene spent saline vials.

The biodegradation of spent saline bottles, a low density polyethylene product (LDPE) by two selected Arthrobacter sp. under in vitro conditions is reported. Chemical and UV pretreatment play a vital role in enhancing the rate of biodegradation. Treated LDPE film exhibits a higher weight loss and density when compared to untreated films. Arthrobacter oxydans and Arthrobacter globiformis grew better in medium containing pretreated film than in medium containing untreated film. The decrease in density and weight loss of LDPE was also more for pretreated film when compared to untreated film indicating the affect of abiotic treatment on mechanical properties of LDPE. The decrease in the absorbance corresponding to carbonyl groups and double bonds that were generated during pretreatment suggest that some of the double bonds were cut by Arthrobacter species. Since Arthrobacter sp. are capable of degrading urea, splitting of urea group were also seen in FTIR spectrum indicating the evidence of biodegradation after microbial incubation. The results indicated that biodegradation rate could be enhanced by exposing LDPE to calcium stearate (a pro-oxidant) which acts as an initiator for the oxidation of the polymers leading to a decrease of molecular weight and formation of hydrophilic group. Therefore, the initial step for biodegradation of many inert polymers depends on a photo-oxidation of those polymers. The application in sufficient details with improved procedures utilizing recombinant microorganism with polymer degradation capacity can lead to a better plastic waste management in biomedical field. The present plastic disposal trend of waste accumulation can be minimized with this promising eco-friendly technique.

Comparative study of serum antioxidant and prooxidant parameters / Монголын Анагаах Ухаан

Background. Demographic transition is indication of population growth rates which impacted by global environmental changes and development of modern science. Last years, number of elderly people dramatically increasing in the world and this increases also showed up in Mongolia. Therefore, investigating the ageing process, risk factors for ageing and age related changes of the human body is important for diagnosing and decreasing age-related disease, improving the quality of life in elderly and healthy ageing. We aimed to investigate age related changes of antioxidant and prooxidant status among healthy Mongolian adults.Materials and Methods. 384 healthy subjects participated in this research. We measured serum level of antioxidant and prooxidant parameters in all subjects at the Functional diagnostic laboratory and Immunology laboratory of the Health Sciences University of Mongolia.Results. Serum level of malondialdehyde (MDA) that is parameter of prooxidant activity was lower in the 21-30 age groups and highest in upper 70 age groups. There was a significantly positive correlation between age and serum MDA level (r=0.665, p 0.01). Serum antioxidant parameters such as superoxide dismutase (SOD, r=-0.357, p 0.01), glutathione (GSH, r=-0.201, p 0.01) and total antioxidant activity (TAC, r=-0.256, p 0.01) has a negative correlation with age. But glutathione peroxidase (GPx, r=0.635, p 0.01) was significantly increased with age. That means the antioxidant activity is decreasing with the ageing process. Regression analyses showed that MDA, GPx, SOD, GSH, and TAC were significantly related with the ageing process.Conclusion. We concluded that the antioxidant activity is decreasing and oxidation process is increasing with age and oxidative stress is higher in healthy Mongolian adults. Furthermore, the serum lipid level is increasing from age 40and it can be the reason for arterial wall thickness.

DNA degradation by aqueous extract of Aloe vera in the presence of copper ions.

The plant Aloe vera has long been used in medicine, as dietary supplements and for cosmetic purposes. Aloe vera extracts are a rich source of polyphenols, such as aloin and aloe emodin and have shown a wide range of pharmacological properties, including anti-inflammatory and anti-cancer properties. The bioactive component aloe emodin has been reported to induce apoptosis in various cancer cell lines. Many of the biological activities of Aloe vera have been attributed to its antioxidant properties. However, most plant-derived polyphenols that are also present in Aloe vera may exhibit pro-oxidant properties either alone or in the presence of transition metals, such as copper. Previous reports from this laboratory have implicated the pro-oxidant action as one of the mechanisms for their anti-cancer properties. In the present paper, we show that aqueous extract of Aloe vera is also able to cause DNA degradation in the presence of copper ions. Further, the extract is also able to reduce Cu(II) to Cu(I) and generate reactive oxygen species, such as superoxide anion and hydroxyl radicals in a dose-dependent manner, which correlates with ability of the extract to cause DNA breakage. Thus, the study shows that in addition to antioxidant activity, Aloe vera extract also possess pro-oxidant properties, leading to oxidative DNA breakage.

The Prospects of Vitamin C in Cancer Therapy

Ascorbate (vitamin C) is a cofactor for a number of metabolic enzymes and is an indisputable essential vitamin C for humans. However, the potential of ascorbate as an anticancer agent has been a topic of controversy. A number of previous reports have addressed both positive aspects and limitations of ascorbate in cancer therapy. In this review, we briefly summarize the potential antitumor effects of ascorbate and its prospects for clinical use.