Free radical research
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Free radical research · Mar 2004
Endogenous and dietary indoles: a class of antioxidants and radical scavengers in the ABTS assay.
Indoles are very common in the body and diet and participate in many biochemical processes. A total of twenty-nine indoles and analogs were examined for their properties as antioxidants and radical scavengers against 2,2'-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) ABTS*+ radical cation. With only a few exceptions, indoles reacted nonspecifically and quenched this radical at physiological pH affording ABTS. ⋯ Radical scavenger activity of indoles against ABTS*+ was higher at physiological pH than at low pH. These results point out to structural compounds with an indole moiety as a class of radical scavengers and antioxidants. This activity could be of biological significance given the physiological concentrations and body distribution of some indoles.
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Free radical research · Aug 2003
A free radical scavenger, edaravone, attenuates steatosis and cell death via reducing inflammatory cytokine production in rat acute liver injury.
Reactive oxygen radicals play an important role in various forms of liver injury. In this study, we evaluated the efficacy of edaravone, a newly synthesized free radical scavenger, in its clinical dosage on an experimental model of acute liver injury in rats. ⋯ Edaravone has a remarkable protective effect on acute liver injury caused by oxygen radicals through not only attenuating the membrane lipid peroxidation, but also inhibiting the production of inflammatory cytokines. We theorize that edaravone may have a clinical benefit in the treatment of various liver injuries.
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Free radical research · Mar 2003
Beneficial effects of poly (ADP-ribose) polymerase inhibition against the reperfusion injury in heart transplantation.
We investigated the effect of 3-aminobenzamide (3-AB), an inhibitor of the nuclear enzyme poly(ADP-ribose) polymerase (PARP), against early ischemia/reperfusion (IR) injury in heart transplantation. In our experimental model, rat heart subjected to heterotopic transplantation, low temperature global ischemia (2 h) was followed by an in vivo reperfusion (60 min). In these conditions, and in the absence of 3-AB treatment, clear signs of oxidative stress, such as lipid peroxidation, increase in protein carbonyls and DNA strand breaks, were evident; PARP was markedly activated in concomitance with a significant NAD+ and ATP depletion. ⋯ Possible mechanisms for these effects are discussed, in any case the present results indicate that PARP inhibition has an overall beneficial effect against myocardial reperfusion injury, mainly due to prevention of energy depletion. In this context, the signs of apoptosis observed under 3-AB treatment might be ascribed to the maintenance of sufficient intracellular energy levels. These latter allow irreversible damages triggered during the ischemic phase to proceed towards apoptosis instead of towards necrosis, as it appears to happen when the energetic pools are depleted by high PARP activity.
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Free radical research · Mar 2003
Evidence for time-dependent maximum increase of free radical damage and eicosanoid formation in the brain as related to duration of cardiac arrest and cardio-pulmonary resuscitation.
Recovery of neurological function in patients following cardiac arrest and cardiopulmonary resuscitation (CPR) is a complex event. Free radical induced oxidative stress is supposed to be involved in this process. We studied levels of 8-iso-PGF2alpha (indicating oxidative injury) and 15-keto-dihydro-PGF2alpha (indicating inflammatory response) in venous plasma obtained from the jugular bulb in a porcine model of experimental cardiopulmonary resuscitation (CPR) where 2, 5, 8, 10 or 12 min of ventricular fibrillation (VF) was followed by 5 or 8 min of closed-chest CPR. ⋯ When compared between the groups there was a duration-dependent maximum increase of 8-iso-PGF2alpha which was greatest in animals subjected to the longest period (VF12 min + CPR8 min) of no or low blood flow. In contrast, the greatest increase of 15-keto-dihydro-PGF2alpha was observed in the 13 min group (VF8 min + CPR5 min). Thus, a time-dependent cerebral oxidative injury occurs in conjunction which cardiac arrest and CPR.
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Free radical research · Feb 2000
The antioxidant activities of seasonings used in Asian cooking. Powerful antioxidant activity of dark soy sauce revealed using the ABTS assay.
Scavenging of the ABTS (2,2'-azinobis[3-ethylbenzothiazoline-6-sulphonate])-derived nitrogen-centred radical cation (ABTS*+) was used to compare the total antioxidant activities of several seasonings used in Asian cooking. The results were expressed as Trolox equivalent antioxidant capacity (TEAC). ⋯ In evaluating the TEAC of commercial products, attention must be paid to the addition of preservatives by manufacturers to the seasonings tested. Sodium benzoate (a preservative added to several seasonings) did not react significantly with ABTS*+, but the sulphite content of certain white wines may have led to an over-estimation of their TEAC.