Abstract Antioxidant Activity Research Articles

Effects of antioxidant activity of black maize in corn borer larval survival and growth

Antioxidant activity (AA) of black maize kernels attributed mainly to polyphenols has potential effects on health and possible defense functions against pests. Our objective was to evaluate the effects of maize polyphenols and AA in survival and growth of larvae of the corn borer Sesamia nonagrioides. We carried out two bioassays with S. nonagrioides larvae grown in artificial diet with white and black maize flour and control. AA was tested spectrophotometrically on each of the diets using four methods. The different measurements of AA were strongly correlated, indicating that these measurements were highly reliable. The control diet, the white-maize-diet and black-maize-diet with vitamin C and without H2O2 had the highest antioxidant activity. The processing of the maize flour altered the AA of the polyphenols. The control treatment had the highest AA, and vitamin C had stronger AA than polyphenols. AA of vitamin C hides that of polyphenols probably due to environmental effects, dilution of polyphenols, or interactions with other substances. Larvae grew more in the control diet and the addition of H2O2 had not significant effects on weight. There was a weak rank correlation between AA and larval weight. Mortality was lowest for the control diet with or without H2O2 followed by white maize with or without H2O2 and black maize without H2O2. Effects of polyphenols depend on other substances that might interact with them. The results indicate that antioxidant activity has insecticide effects on young larvae and, as the larvae grow, antioxidants have positive effects on larvae.

Preliminary Investigation of Bioactivity of Green Tea (Camellia Sinensis), Rooibos (Asphalatus Linearis), and Yerba Mate (Ilex Paraguariensis)

Antioxidant activity (AOA) of three kinds of herbal teas was tested through determination on total phenolics content, total antioxidant activity, ferrous ion-chelating ability, as well as antimicrobial activity, and activity effects on enzyme catalase. Green tea showed the highest total phenolics and best ferrous ion-chelating ability. The teas were not effective against bacteria, although they had an activating effect on enzyme catalase.

Antioxidant activity of free radical reactions inhibitors, applied to the dressing material for wound healing

Antioxidant activity (AA) of inhibitors of free radical reactions (FRR) (dieton, mexidol, trypsin), applied to the dressing material for wound healing was studied using a model system containing suspension of laminated liposomes, formed from the fraction of total chicken yolk phospholipids. Lipid peroxidation (LPO) of liposome membranes was initiated by addition of Fe2+ ions. The kinetics of FRR was monitored by coumarin enhanced chemiluminescence (CL). AA of the inhibitors was determined by their ability to intercept aqueous and hydrophobic free radicals and chelate Fe2+ ions. Their ability to intercept radicals reduced in the following order: dieton > trypsin > mexidol. We have also found previously unknown ability of mexidol to interact with Fe2+ and to eliminate the FRR catalyst. Studying AA of the FRR inhibitors in the two-components mixture, containing dieton and mexidol, we have observed the multifunctional effect: dieton increased the duration of latent period of CL by intersepting lipid peroxyl radicals, while mexidol, decreased this parameter by interacting with Fe2+, i.e. mexidol masked the action of dieton. Study of AA of two-components mixture, containing mexidol and trypsin has demonstrated the same multifunctional effect. In the two-component mixture, containing trypsin and dieton, the inhibitors exhibit synergistic action. All the antioxidant properties of these FRR inhibitors were also preserved in the three component mixture. Thus, the mixture dieton, mexidol and trypsin, possesses high AA, that validates their use in the dressing materials employed for wound healing.