ascorbic-acid and troxerutin

The present study was aimed to investigate the chemopreventive potential of troxerutin on 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the antioxidant and lipid peroxidation (LPO) status. Rats were randomly divided into six groups. Group I rats served as control. Group II rats received troxerutin (50 mg/kgb.w., p.o.) for 16 weeks. Groups III-VI rats received subcutaneous injections of DMH (20 mg/kgb.w., s.c.) once a week, for the first 4 weeks. In addition to DMH, groups IV-VI rats received troxerutin at the doses of 12.5, 25 and 50 mg/kgb.w., respectively. In DMH treated rats, our results showed decreased activities of antioxidants and increased levels of LPO in the liver. Moreover, LPO and antioxidants in the colon were found to be significantly diminished in DMH the treated rats. Furthermore, enhanced activity of colonic vitamin C and vitamin E levels were observed in DMH alone treated rats (group III), which was significantly reversed on troxerutin supplementation. Troxerutin at the dose of 25 mg/kgb.w. had shown profound beneficial effects by exhibiting near normal biochemical profile and well-preserved colon histology as compared to the other two tested doses (12.5 and 50 mg/kgb.w.). These findings suggest that troxerutin could serve as a novel agent for colon cancer chemoprevention.

Topics: 1,2-Dimethylhydrazine; Administration, Oral; Animals; Antineoplastic Agents; Ascorbic Acid; Carcinogens; Catalase; Colon; Colonic Neoplasms; Glutathione; Hydroxyethylrutoside; Lipid Peroxidation; Liver; Male; Rats; Rats, Wistar; Superoxide Dismutase; Vitamin E

Arachidonic acid was investigated for its vascular permeabilizing potential in the rat peritoneal cavity and for its mechanism of action. The antagonistic potential of antioxidants (vitamin E, vitamin C and troxerutin) was also evaluated. Vascular permeability was equated to the rate of extravasation of Evans blue dye from plasma into the peritoneal cavity. Baseline permeability was linear up to 2 h, with a rate constant (k) of 0.0031+/-0.0007 h(-1). Intravenous arachidonate (from 30 microg/kg to 3 mg/kg) induced an immediate, dose-related and significant increase in permeability (ranging from 80% to 150%), which was comparable to the effect induced by similar doses of serotonin. Aspirin (10 mg/kg) reduced the arachidonate-induced permeability by 75%, but interestingly neither the stable thromboxane A(2) receptor agonist U46619 (prostaglandin H(2) endoperoxide epoxymethane) nor prostacyclin was able to increase peritoneal vascular permeability. In contrast, the permeabilizing action of arachidonic acid was very sensitive to antioxidant agents. Thus, vitamin C and the flavonoid compound troxerutin (100 mg/kg) fully abolished arachidonate-induced permeability, whereas vitamin E had only a partial effect (40-100% inhibition). In conclusion, intravenous administration of arachidonic acid strongly enhanced peritoneal vascular permeability in the rat, apparently via free radical generation. This rat peritoneal model can be used to evaluate the in vivo antinflammatory potential of antioxidant drugs.

Topics: Animals; Antioxidants; Arachidonic Acid; Ascorbic Acid; Capillary Permeability; Coloring Agents; Disease Models, Animal; Evans Blue; Extravasation of Diagnostic and Therapeutic Materials; Hydroxyethylrutoside; Injections, Intravenous; Male; Peritoneal Cavity; Rats; Rats, Wistar; Reactive Oxygen Species; Time Factors; Vitamin E

By its 'protective function', human skin is a potential target for the production of free radicals. The role played by topically applied antioxidants as inhibitors of oxidative stress damage was felt to be worth investigation.. To investigate the free radical scavenging (superoxide, hydroxyl and peroxyl radicals) and skin penetration of troxerutin in association with ascorbyl palmitate and alpha-tocopheryl succinate, esters of two vitamins commonly used in skin care products.. The compounds' scavenging activities, in a concentration-dependent manner, were as follows: hydroxyl radicals in a Fenton-based assay; superoxide radicals in a hypoxanthine/xanthine oxidase system; and lipid peroxidation inhibition of liver microsomes was induced by 2,2'-azobis-(2-amidinopropane) dihydrochloride (ABAP).. A synergic action was observed between alpha-tocopheryl succinate and troxerutin for hydroxyl radical scavenging, between the three compounds for superoxide scavenging and between troxerutin and ascorbyl palmitate in lipid peroxidation inhibition.. Using a stripping method, it was shown that the three substances, incorporated in a pharmaceutical preparation, permeated through human epidermis. Thus, this association can improve skin care products for preventing free radical-mediated damage.

Topics: Adult; Animals; Antioxidants; Ascorbic Acid; Chromatography, High Pressure Liquid; Drug Combinations; Female; Free Radical Scavengers; Free Radicals; Gels; Humans; Hydroxyethylrutoside; Lipid Peroxidation; Male; Microsomes, Liver; Oxidative Stress; Rats; Rats, Wistar; Skin; Skin Absorption; Tocopherols; Vitamin E

The endothelo-protective activity of a series of low-molecular oxygen-derived free radical scavengers (OFRS) was tested in rats. A model of endothelaemia provoked by intravenous administration of hydrogen peroxide was used. With each OFRS the activity in the hydrogen peroxide model was compared with that in the less specific model using the provocation by citrate as a calcium chelating agent. Relatively unspecific but biologically important OFRS, ascorbic acid, tocopherol, troxerutin and glutathione were tested in the first phase of the study. A marked optimum of endothelo-protective activity was shown with all agents, the optimum against hydrogen peroxide having been observed at doses from 3 to 50 times lower than against citrate. Ascorbic acid, troxerutin and the combination of both were also tested in another model based on leg ischaemia produced by ligature of the common femoral artery. Without OFRS, a marked increase of endothelaemia was observed after 30-60 min ischaemia showing a second peak after the release of the ligature. This second peak was completely abolished by the preventive administration of OFRS in a dose which was also effective in the hydrogen peroxide model.

Topics: alpha-Tocopherol; Animals; Anticoagulants; Ascorbic Acid; Aspirin; Coronary Disease; Endothelium; Female; Femoral Artery; Free Radicals; Heparin; Hydrogen Peroxide; Hydroxyethylrutoside; Kinetics; Lactates; Lactic Acid; Perfusion; Pyruvates; Pyruvic Acid; Rats; Rats, Inbred Strains; Rutin; Tocopherols; Vitamin E