Search results for " Radical"
showing 10 items of 757 documents
Regulation of vascular function and inflammation via cross talk of reactive oxygen and nitrogen species from mitochondria or nadph oxidase—implicatio…
2020
Oxidative stress plays a key role for the development of cardiovascular, metabolic, and neurodegenerative disease. This concept has been proven by using the approach of genetic deletion of reactive oxygen and nitrogen species (RONS) producing, pro-oxidant enzymes as well as by the overexpression of RONS detoxifying, antioxidant enzymes leading to an amelioration of the severity of diseases. Vice versa, the development and progression of cardiovascular diseases is aggravated by overexpression of RONS producing enzymes as well as deletion of RONS detoxifying enzymes. We have previously identified cross talk mechanisms between different sources of RONS, which can amplify the oxidative stress-m…
Chemical Composition, In Vitro Antitumor and Pro-Oxidant Activities of Glandora rosmarinifolia (Boraginaceae) Essential Oil
2018
The biological properties of essential oils have been demonstrated in the treatment of several diseases and to enhance the bioavailability of other drugs. In natural habitats the essential oils compounds may play important roles in the protection of the plants as antibacterials, antivirals, antifungals, insecticides and also against herbivores by reducing their appetite for such plants or by repelling undesirable others. We analyzed by gas-chromatography mass spectrometry the chemical composition of the essential oil of aerial parts of Glandora rosmarinifolia (Ten.) D.C. Thomas obtained by hydrodistillation and verified some biological activities on a panel of hepatocellular carcinoma cell …
Mechanism of the OH Radical Addition to Adenine from Quantum-Chemistry Determinations of Reaction Paths and Spectroscopic Tracking of the Intermediat…
2016
The OH radical is a well-known mediator in the oxidation of biological structures like DNA. Over the past decades, the precise events taking place after reaction of DNA nucleobases with OH radical have been widely investigated by the scientific community. Thirty years after the proposal of the main routes for the reaction of •OH with adenine (Vieira, A.; Steenken, S. J. Am. Chem. Soc. 1990, 112, 6986−6994), the present work demonstrates that the OH radical addition to C4 position is a minor pathway. Instead, the dehydration process is mediated by the A5OH adduct. Conclusions are based on density functional theory calculations for the ground-state reactivity and highly accurate multiconfigur…
Study of interaction of antimutagenic 1,4-dihydropyridine AV-153-Na with DNA-damaging molecules and its impact on DNA repair activity
2018
Background1,4-dihydropyridines (1,4-DHP) possesses important biochemical and pharmacological properties, including antioxidant and antimutagenic activities. It was shown that the antimutagenic 1,4-dihydropyridine AV-153-Na interacts with DNA. The aim of the current study was to test the capability of the compound to scavenge peroxynitrite and hydroxyl radical, to test intracellular distribution of the compound, and to assess the ability of the compound to modify the activity of DNA repair enzymes and to protect the DNA in living cells against peroxynitrite-induced damage.MethodsPeroxynitrite decomposition was assayed by UV spectroscopy, hydroxyl radical scavenging—by EPR spectroscopy. DNA b…
Could lymphadenectomy be avoided in locally advanced cervical cancer patients administered preoperative chemoradiation? A large-scale retrospective s…
2017
Abstract Introduction To identify a subset of cervical cancer (CC) patients administered chemoradiation (CT/RT) plus radical surgery (RS), who can be spared lymphadenectomy, and complications. Patients and methods 430 Stage IB2-IIB patients without LN involvement at imaging were accrued (March 1996–December 2015) at Gynecologic Oncology Unit of the Catholic University of Rome/Campobasso. CT/RT consisted of pelvic irradiation plus cisplatin based chemotherapy. Objective response was evaluated according to RECIST criteria; radical hysterectomy and pelvic ± aortic lymphadenectomy was attempted in patients achieving response or stable disease. Surgical morbidity was classified according to the …
Tetrabromobisphenol A (TBBPA)-stimulated reactive oxygen species (ROS) production in cell-free model using the 2′,7′-dichlorodihydrofluorescein diace…
2016
t Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant, applied in a variety of commercial and household products, mainly electronic ones. Since the production of reactive oxygen species (ROS) is considered one of the principal cytotoxicity mechanisms, numerous studies undertake that aspect of TBBPA’s mechanism of action. The present study verifies if the fluorogenic substrate 2′,7′- dichlorodihydrofluorescein diacetate (H2DCFDA) should be used to detect ROS production induced by TBBPA. To determine the ability of TBBPA alone to stimulate the conversion of H2DCFDA to its fluorescent product 2’, 7’- dichlorofluorescein (DCF), we used a cell-free model. In the experiments…
Exercise training as a drug to treat age associated frailty
2016
Exercise causes an increase in the production of free radicals [1]. As a result of a hormetic mechanism antioxidant enzymes are synthesised and the cells are protected against further oxidative stress. Thus, exercise can be considered as an antioxidant [2]. Age-associated frailty is a major medical and social concern as it can easily lead to dependency. In this review we describe that oxidative stress is associated with frailty and the mechanism by which exercise prevents age-associated frailty. We propose that individually tailored multicomponent exercise programmes are one of the best ways to prevent and to treat age-associated frailty.
Prooxidative chain transfer activity by thiol groups in biological systems
2020
Cysteine is arguably the best-studied biological amino acid, whose thiol group frequently participates in catalysis or ligand binding by proteins. Still, cysteine's unusual biological distribution has remained mysterious, being strikingly underrepresented in transmembrane domains and on accessible protein surfaces, particularly in aerobic life forms (“cysteine anomaly”). Noting that lipophilic thiols have been used for decades as radical chain transfer agents in polymer chemistry, we speculated that the rapid formation of thiyl radicals in hydrophobic phases might provide a rationale for the cysteine anomaly. Hence, we have investigated the effects of dodecylthiol and related compounds in i…
Protecting group-free radical decarboxylation of bile acids: Synthesis of novel steroidal substituted maleic anhydrides and maleimides and evaluation…
2017
Abstract We report the first Barton radical decarboxylation of unprotected bile acids via in situ irradiation of their thiohydroxamic esters in the presence of citraconic anhydride and citracoimide, leading to the synthesis a series of steroidal maleic anhydrides and maleimides as novel hybrid bile acids. The cytotoxic activities were evaluated on C6 rat glioma cells.