The use of antioxidants to prevent intracellular free radical damage is an area currently attracting considerable research interest. The compound 2',7'-dichlorofluorescin diacetate (DCFH-DA) is a probe for intracellular peroxide formation commonly used in such studies. During our studies we unexpectedly found that incubation of Trolox, a water soluble vitamin E analog, with DCFH-DA in cell-free...

The antioxidative activity of α-tocopherol and Trolox, a water-soluble carboxylic acid derivative of α-tocopherol, in an emulsion stabilized with the hydrophilic emulsifier, polyoxyethylene (20) sorbitan monolaurate, was evaluated by measuring the changes in linoleic acid content, peroxide value, and thiobarbituric acid value. The activity of α-tocopherol and Trolox to depress the autoxidation ...

abstract background: sperm parameters and motion kinetics are affected by cryopreservation. objective: the main purpose of the current study was to determine the effect of different concentrations of trolox as an antioxidant to freezing-thawing procedure on human sperm kinematic parameter. materials and methods: semen was collected from 20 normal donors and divided into five aliquots prior to c...

The radical-scavenging activities of the flavanones hesperetin and hesperidin were investigated by differential scanning calorimetry (DSC) monitoring of the polymerization of methyl methacrylate initiated by 2,2'-azobisisobutyronitrile (AIBN, an R* radical) or benzoylperoxide (BPO, a PhCOO* radical) at 70 degrees C under nearly anaerobic conditions. Their stoichiometric factor (number of free r...

The process of cryopreservation results in high concentration of reactive oxygen species which is detrimental to spermatozoa. The aim of this study was to investigate whether addition of vitamin E analogue to freezing extender can facilitate the cryosurvival of spermatozoa in rabbits, and how vitamin E protects spermatozoa against damages during the process of preservation. Freshly ejaculated s...

In the present study, we tried to establish an efficient assay for total antioxidant capacity (TAC) in human plasma using a 96-well microplate. TAC was assessed using lag time by antioxidants against the myoglobin-induced oxidation of 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) with hydrogen peroxide, and expressed as Trolox equivalent. The linearity of the calibration curve with...

Selenite (SeL) or selenomethionine (SeM) are the most common selenium (Se) compounds taken as dietary antioxidants to reduce oxidative stress. Because the public may frequently supplement Se compounds at high doses, the possible pro-oxidant effect of Se becomes a concern. SeL and SeM have entirely different pharmacokinetic effects based on dose-related cytotoxicity. Our laboratory has shown pre...

The total antioxidant capacities (TAC) of feces of mammalian herbivores and carnivores were compared. TAC were estimated using three different methods: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS*) reduction, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH*) reduction, and ferric reducing antioxidant power (FRAP). TAC of 18 herbivorous species were generally higher with res...

The initial events after photoexcitation and photoionization of α-tocopherol (vitamin E) and the analogue Trolox C have been studied by femtosecond stimulated Raman spectroscopy, transient absorption spectroscopy and time-resolved infrared spectroscopy. Using these techniques it was possible to follow the formation and decay of the excited state, neutral and radical cation radicals and the hydr...