Elevated copper and oxidative stress in cancer cells as a target for cancer treatment

Novel multifunctional polymers from aromatic diamines by oxidative polymerizations.

Much work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. We analysed the antioxidant activity of the rutin (quercetin-3-rhamnosyl glucoside) using different assays including: total antioxidant activity and reducing power, hydroxyl radical scavenging assay, superoxide radical scavenging assay, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay and lipid peroxidation assay which uses egg yolk as the lipid-rich source. Total antioxidant capacity was determined by the assay based on the decrease in absorbance of β-carotene by the sample. Rutin exhibited strong DPPH radical scavenging activity. At the concentration of 0.05 mg/ml, ascorbic acid (Vc), butylated hydroxytoluene (BHT) and rutin showed 92.8%, 58.8%, and 90.4% inhibition, respectively. In addition, rutin had effective inhibition of lipid peroxidation. Those various antioxidant activities were compared to standard antioxidants such as BHT and Vc.

In vitro antioxidant properties of rutin

Montmorillonite as a drug delivery system: intercalation and in vitro release of timolol maleate.

A platinum electrode was modified with electropolymerized films of 4-allyl-2-methoxyphenol (eugenol) by its oxidative polymerization from an alkaline solution by cyclic voltammetry. The modified electrode was than used to determine dopamine (DA) in an excess of ascorbic acid (AA) by differential pulse voltammetry. The peak positions as well as relative sensitivity DA/AA were affected by the potential window applied for the polymerization. For polymerization between 0 and 2.2 V, the peak potentials recorded in a phosphate buffer solution (pH 7.4) were −61 and +152 mV vs Ag/AgCl for AA and DA, respectively. After a 5-min equilibration, relative sensitivity DA/AA was 164 and the current sensitivity for DA was 7.9 nA μM-1. The detection limit for S/N = 3 is 0.1 μM. The high selectivity and sensitivity for DA was found to be due to charge discrimination/analyte accumulation and an effect of catalytic mediation of redox sites. Chronocoulometric data reveal that DA is accumulated on the electrode as a monolayer....

Polyeugenol-modified platinum electrode for selective detection of dopamine in the presence of ascorbic Acid.

Antioxidant activity and proline content of leaf extracts from Dorystoechas hastata

Laccase immobilized polyacrylamide-alginate cryogel: A candidate for treatment of effluents

An amperometric biosensor for glucose based on a novel polymeric matrix is described. The sensor was prepared by electrochemical polymerization of p-aminophenol in the presence of glucose oxidase on Pt substrates in a KCl solution at a potential of 0.6 V (vs. Ag/AgCl). The chronoamperometric response of poly(p-aminopheno1)-glucose oxidase biosensor to hydrogen peroxide formed as the result of enzymatic reaction was measured at a potential of 0.7 V (vs. Ag/AgCl) in PBS solution. It was shown that a biosensor prepared by this one- step procedure has a linear range up to 6mM glucose, a response time less than 5 s and a lifetime around 15 days. The sensitivity of the electrode was superior to that of much publicized polypyrrole based glucose oxidase electrode. Also, the substrate selectivity of PAP/GOx electrode was tested for coexisting substances such as lactose, sucrose, urea, paracetamol, uric and ascorbic acid and no discernible anodic response was observed above the background current.

The preparation and sensor application of poly(p‐aminophenol)

Background: Considerable evidences have linked oxidative damage and cancer. In this article, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) activities, and malondialdehyde (MDA) and nitric oxide metabolites' levels (NOx) were investigated in patients with stomach cancer. Methods: All measurments were done by spectrophotometric techniques. Results: We observed a significant decrease in the activities of SOD and CAT in tumour tissues when compared with control tissues. The different of GSHPx activities and NO metabolite' levels were not statistically significant. MDA levels were significantly increased. Conclusions: We conclude that increased MDA levels and decreased antioxidant enzyme activities can be valuable parameters in assessing the possible risk of cancer.

Arife Alev Karagözler

Papers

Antioxidant activity and proline content of leaf extracts from Dorystoechas hastata

Laccase immobilized polyacrylamide-alginate cryogel: A candidate for treatment of effluents

The preparation and sensor application of poly(p‐aminophenol)

Lipid peroxidation and antioxidant status in stomach cancer.

Magnetic hydrophobic affinity nanobeads for lysozyme separation