Target type: biologicalprocess
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an oxygen radical stimulus. An oxygen radical is any oxygen species that carries a free electron; examples include hydroxyl radicals and the superoxide anion. [GOC:krc, ISBN:0124325653]
Response to oxygen radicals is a complex biological process that involves a cascade of events initiated by the generation of reactive oxygen species (ROS). ROS are highly reactive molecules containing oxygen, such as superoxide anion (O2-), hydrogen peroxide (H2O2), and hydroxyl radical (OH-), which can damage cellular components like DNA, proteins, and lipids. Cells have evolved sophisticated mechanisms to defend against ROS, including both enzymatic and non-enzymatic antioxidant systems.
The process begins with the production of ROS, which can arise from various sources like normal cellular metabolism, exposure to environmental toxins, inflammation, and radiation. These ROS can then interact with and damage cellular components, leading to oxidative stress.
To counter this stress, cells employ a multitude of defense strategies. Enzymatic antioxidants, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase, catalyze the conversion of ROS into less harmful molecules. Non-enzymatic antioxidants, including vitamins C and E, glutathione, and uric acid, directly scavenge ROS or act as reducing agents to prevent further damage.
The response to oxygen radicals also involves signaling pathways that activate gene expression and protein production. For instance, the transcription factor Nrf2 plays a crucial role in inducing the expression of antioxidant enzymes. Moreover, cells can activate repair mechanisms to repair damaged components, such as DNA repair pathways.
Overall, the response to oxygen radicals is an intricate process that involves the generation of ROS, cellular defense mechanisms, and signaling pathways. This intricate interplay ensures that cells maintain a delicate balance between ROS production and detoxification, thereby preventing oxidative stress and promoting cellular health.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Thioredoxin reductase 2, mitochondrial | A thioredoxin reductase 2, mitochondrial that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9NNW7] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 3,5-dinitro-4-chloro-alpha,alpha,alpha-trifluorotoluene | 3,5-dinitro-4-chloro-alpha,alpha,alpha-trifluorotoluene: affects mitochondria isolated from rat liver; RN given refers to unlabeled cpd | ||
| naphthazarin | naphthazarin : A naphthoquinone that is 1,4-naphthoquinone in which the hydrogens at positions 5 and 8 are replaced by hydroxy groups. naphthazarin: fish toxin; isolated for first time from the walnut onigurmi, Juglans mandshurica maxim var. Sieboldiana Makino; structure | hydroxy-1,4-naphthoquinone | acaricide; antibacterial agent; antineoplastic agent; apoptosis inducer; geroprotector; plant metabolite |
| 2,6-dichloroindophenol | 2,6-dichloroindophenol : A quinone imine that is indophenol substituted by chloro groups at positions 2 and 6. 2,6-Dichloroindophenol: A dye used as a reagent in the determination of vitamin C. N-3,5-dichloro-4-hydroxyphenyl-1,4-benzoquinone imine : 1,4-benzoquinone imine having a 3,5-dichloro-4-hydroxyphenyl substituent attached to the nitrogen atom. | dichlorobenzene; quinone imine | |
| 4-aminophenylarsenoxide | 4-aminophenylarsenoxide: RN given refers to parent cpd | ||
| tetramethylpyrazine | tetramethylpyrazine : A member of the class of pyrazines that is pyrazine in which all four hydrogens have been replaced by methyl groups. An alkaloid extracted from Chuanxiong (Ligusticum wallichii). tetramethylpyrazine: found in Ligusticum chuanxiong | alkaloid; pyrazines | antineoplastic agent; apoptosis inhibitor; bacterial metabolite; neuroprotective agent; platelet aggregation inhibitor; vasodilator agent |
| palmarumycin cp(1) | palmarumycin CP(1): a type of spirobisnaphthalene, which contain two naphthalene-derived c10 units bridged through a spiroketal linkage with two oxygen bridges; structure in first source | ||
| xanthohumol | xanthohumol : A member of the class of chalcones that is trans-chalcone substituted by hydroxy groups at positions 4, 2' and 4', a methoxy group at position 6' and a prenyl group at position 3'. Isolated from Humulus lupulus, it induces apoptosis in human malignant glioblastoma cells. xanthohumol: from hop plant, Humulus lupulus | aromatic ether; chalcones; polyphenol | anti-HIV-1 agent; antineoplastic agent; antiviral agent; apoptosis inducer; EC 2.3.1.20 (diacylglycerol O-acyltransferase) inhibitor; metabolite |
| curcumin | curcumin : A beta-diketone that is methane in which two of the hydrogens are substituted by feruloyl groups. A natural dyestuff found in the root of Curcuma longa. Curcumin: A yellow-orange dye obtained from tumeric, the powdered root of CURCUMA longa. It is used in the preparation of curcuma paper and the detection of boron. Curcumin appears to possess a spectrum of pharmacological properties, due primarily to its inhibitory effects on metabolic enzymes. | aromatic ether; beta-diketone; diarylheptanoid; enone; polyphenol | anti-inflammatory agent; antifungal agent; antineoplastic agent; biological pigment; contraceptive drug; dye; EC 1.1.1.205 (IMP dehydrogenase) inhibitor; EC 1.1.1.21 (aldehyde reductase) inhibitor; EC 1.1.1.25 (shikimate dehydrogenase) inhibitor; EC 1.6.5.2 [NAD(P)H dehydrogenase (quinone)] inhibitor; EC 1.8.1.9 (thioredoxin reductase) inhibitor; EC 2.7.10.2 (non-specific protein-tyrosine kinase) inhibitor; EC 3.5.1.98 (histone deacetylase) inhibitor; flavouring agent; food colouring; geroprotector; hepatoprotective agent; immunomodulator; iron chelator; ligand; lipoxygenase inhibitor; metabolite; neuroprotective agent; nutraceutical; radical scavenger |
| ellagic acid | catechols; cyclic ketone; lactone; organic heterotetracyclic compound; polyphenol | antioxidant; EC 1.14.18.1 (tyrosinase) inhibitor; EC 2.3.1.5 (arylamine N-acetyltransferase) inhibitor; EC 2.4.1.1 (glycogen phosphorylase) inhibitor; EC 2.5.1.18 (glutathione transferase) inhibitor; EC 2.7.1.127 (inositol-trisphosphate 3-kinase) inhibitor; EC 2.7.1.151 (inositol-polyphosphate multikinase) inhibitor; EC 2.7.4.6 (nucleoside-diphosphate kinase) inhibitor; EC 2.7.7.7 (DNA-directed DNA polymerase) inhibitor; EC 5.99.1.2 (DNA topoisomerase) inhibitor; EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor; food additive; fungal metabolite; geroprotector; plant metabolite; skin lightening agent | |
| (1,2-bis(1,2-benzisoselenazolone-3(2h)-ketone))ethane | (1,2-bis(1,2-benzisoselenazolone-3(2H)-ketone))ethane: has antineoplastic activity; structure in first source | ||
| flavellagic acid | flavellagic acid: RN given refers to parent cpd; structure |