Search results for "Active oxygen"
showing 10 items of 884 documents
Beauvericin and ochratoxin A mycotoxins individually and combined in HepG2 cells alter lipid peroxidation, levels of reactive oxygen species and glut…
2020
The co-presence of more than one mycotoxin in food is being evidenced in last food surveys as reported in the literature. Beauvericin (BEA) is a non-legislated emergent mycotoxin while Ochratoxin A (OTA) has been widely studied and legislated. Concentration range individually studied was from 2.5 to 0.3 μM for BEA and from 25 to 3.1 μM for OTA; binary mixture [BEA + OTA] comprised concentrations of 1:10 ratio from [2.5 + 25] to [3.1 + 0.3] μM. Potential of toxicity of BEA in HepG2 cells was the highest at all times assayed (24, 48 and 72h). LPO was performed through malondyaldehyde (MDA) detection denoting in the binary mixture for [1.25 + 12.5] μM and at 24 and 72h the highest disturbance …
Progress of Phototherapy Applications in the Treatment of Bone Cancer
2021
Bone cancer including primary bone cancer and metastatic bone cancer, remains a challenge claiming millions of lives and affecting the life quality of survivors. Conventional treatments of bone cancer include wide surgical resection, radiotherapy, and chemotherapy. However, some bone cancer cells may remain or recur in the local area after resection, some are highly resistant to chemotherapy, and some are insensitive to radiotherapy. Phototherapy (PT) including photodynamic therapy (PDT) and photothermal therapy (PTT), is a clinically approved, minimally invasive, and highly selective treatment, and has been widely reported for cancer therapy. Under the irradiation of light of a specific wa…
Insight into the primary mode of action of TiO2 nanoparticles on Escherichia coli in the dark.
2015
16 pages; International audience; Large-scale production and incorporation of titanium dioxide nanoparticles (NP-TiO2 ) in consumer products leads to their potential release into the environment and raises the question of their toxicity. The bactericidal mechanism of NP-TiO2 under UV light is known to involve oxidative stress due to the generation of reactive oxygen species. In the dark, several studies revealed that NP-TiO2 can exert toxicological effects. However, the mode of action of these nanoparticles is still controversial. In the present study, we used a combination of fluorescent probes to show that NP-TiO2 causes Escherichia coli membrane depolarization and loss of integrity, lead…
Targeting antioxidants to mitochondria: a potential new therapeutic strategy for cardiovascular diseases.
2007
Mitochondria produce large amounts of free radicals and play an important role in the life and death of a cell. Thus, mitochondrial oxidative damage and dysfunction contribute to a number of cell pathologies that manifest themselves through a range of conditions including ischemia-reperfusion injury, sepsis, diabetes, atherosclerosis and, consequently, cardiovascular diseases (CVD). In fact, endothelial dysfunction, characterized by a loss of nitric oxide (NO) bioactivity, occurs early on in the development of atherosclerosis, and determines future vascular complications. Although the molecular mechanisms responsible for mitochondria-mediated disease processes are not yet clear, oxidative s…
Water Extract of Cryphaea heteromalla (Hedw.) D. Mohr Bryophyte as a Natural Powerful Source of Biologically Active Compounds
2019
Bryophytes comprise of the mosses, liverworts, and hornworts. Cryphaea heteromalla, (Hedw.) D. Mohr, is a non-vascular lower plant belonging to mosses group. To the date, the most chemically characterized species belong to the liverworts, while only 3.2% and 8.8% of the species belonging to the mosses and hornworts, respectively, have been investigated. In this work, we present Folin–Ciocalteu and oxygen radical absorbance capacity (ORAC) data related to crude extracts of C. heteromalla obtained by three di erent extraction solvents: pure water (WT), methanol:water (80:20 v/v) (MET), and ethanol:water (80:20 v/v) (ETH). The water extract proved to be the best solvent showing the highest con…
SYNTHESIS OF PYRROLO[3,2-H]QUINOLINONES WITH GOOD PHOTOCHEMOTHERAPEUTIC ACTIVITY AND NO DNA DAMAGE
2010
In the search for new photochemotherapeutic agents, a series of derivatives of the ring system pyrrolo[3,2-h]quinoline--bioisosters of the angular furocoumarin angelicin--were synthesized through a four-step synthetic approach, in reasonable overall yields. Eight of the synthesized derivatives showed a remarkable phototoxicity against a panel of four human tumor cell lines and a great dose UV-A dependence, reaching IC₅₀ values at submicromolar level. The mode of cellular death photoinduced by pyrrolo[3,2-h]quinolines was evaluated through a series of flow cytometric analysis and other tests were performed to clarify their mechanism of action.
An in vitro procedure for evaluation of early stage oxidative stress in an established fish cell line applied to investigation of PHAH and pesticide …
2004
Oxidative stress by increased production of reactive oxygen species such as superoxide has been implicated in the toxicity of PCB's and non-target toxicity of many pesticides. We report the development of a microplate-based method for determination of early stage oxidative stress using an established cell line (EPC) from a skin tumour of carp Cyprinus carpio L. and 2',7'-dichlorodihydrofluorescein diacetate (H(2)-DCFDA) as a fluorescent probe for detection of reactive oxygen species (ROS) formation. Sublethal concentrations of the herbicide Paraquat, an established redox cycling agent and a crude PCB mixture, Arochlor 1254 elicited a linear increase in ROS formation over 2 h exposure which …
Effects of pharmacological agents on the lifespan phenotype of Drosophila DJ-1beta mutants.
2010
Mutations in the DJ-1 gene cause autosomal recessive, early-onset Parkinsonism. The DJ-1 protein exerts a protective role against oxidative stress damage, working as a cellular oxidative stress sensor, and it seems to regulate gene expression at different levels. In Drosophila, two DJ-1 orthologs have been identified: DJ-1β and DJ-1β. Several studies have shown that loss of DJ-1β function causes Parkinson's disease (PD)-like phenotypes in flies such as age-dependent locomotor defects, reduced lifespan, and enhanced sensitivity to toxins that induce oxidative stress, like the herbicide paraquat. However, no dopaminergic neurodegeneration is observed. These results suggested that both locomot…
Hypothesis: can N-acetylcysteine be beneficial in Parkinson's disease?
1999
Based on the finding of decreased mitochondrial complex I activity in the substantia nigra of patients with Parkinson's disease, we propose that the consequent reduction of ATP synthesis and increased generation of reactive oxygen species may be a possible cause of nigrostriatal cell death. Since sulfhydryl groups are essential in oxidative phosphorylation, thiolic antioxidants may contribute to the preservation of these proteins against oxidative damage. In the present paper, we hypothesize that treatment with a sulfur-containing antioxidant such as N-acetylcysteine may provide a new neuroprotective therapeutic strategy for Parkinson's disease.
An Alternative to the Human Hemoglobin Test in the Investigation of Bloodstains Treated with Active Oxygen: The Human Glycophorin A Test
2011
In criminal investigations, there are three stages involved when studying bloodstains: search and orientation, confirmation, and individualization. Confirmatory tests have two aims: to show that the stain contains a human biological fluid and to confirm the type of biological fluid. The need to determine the nature of the evidence is reflected in the latest bibliography, where the possibility of employing mRNA and miRNA markers for this purpose is proposed. While these new proposals are being investigated, the kits for determining human hemoglobin currently provide a simple solution for resolving this issue. With these kits, the possibility of obtaining false positives and false negatives i…