antioxidant

Overview

An antioxidant is a substance or system that slows, prevents, or counteracts oxidation, particularly the formation and propagation of reactive oxygen species (ROS) and other free-radical intermediates. In biology and medicine, antioxidants are important because excessive oxidative stress can damage lipids, proteins, and nucleic acids and contribute to inflammation, tissue injury, aging, metabolic dysfunction, neurodegeneration, and impaired wound repair. Antioxidants may act by directly scavenging radicals, chelating redox-active metals, interrupting lipid peroxidation chains, or supporting endogenous defense systems such as Superoxide Dismutase (SOD) and glutathione-dependent pathways.

In recent biomedical research, antioxidants are frequently studied as components of complex therapeutic strategies rather than as stand-alone agents. They appear in investigations of inflammatory disease, metabolic syndrome, liver injury, skin repair, fertility, encephalitis, and mitochondrial dysfunction, often alongside compounds such as rutin, melatonin, coenzyme Q10, resveratrol, quercetin, and polyphenol. Their effects are commonly interpreted in relation to pathways including MAPK, PI3K/AKT/mTOR, FOXO1, nuclear factor kappa B, and mitochondrial quality-control mechanisms such as mitophagy.

Recent Publications Summary

Recent work on antioxidants as a therapeutic target spans natural product characterization, engineered nanomaterials, and mechanism-focused reviews of oxidative stress in chronic disease. Several studies pursued the isolation and quantification of antioxidant capacity in plant matrices, while others tested whether antioxidant delivery can be made selective enough to correct redox imbalance at a specific lesion.

Among plant-derived preparations, an ultrasound-assisted extraction protocol for dandelion (Taraxacum officinale) was optimized by response surface methodology with a Box-Behnken design, converging on 30 min sonication at 70% amplitude and 40 °C; under these conditions total phenolics reached 40.77 mg GAE/g and total flavonoids 22.68 mg RE/g, with antioxidant activity of 88.55% DPPH scavenging, 445.39 µM TE/mg by ABTS, and 30.64 by FRAP 42068787May. Comparable phytochemical work evaluated Cucurbita maxima leaf aqueous extract, combining LC-MS profiling with in vitro, in vivo, and in silico approaches to test its traditional use against inflammation, fever, and oxidative stress-related disorders 41638458Feb, and Costus pictus methanolic leaf extract was subjected to toxicological profiling in in vitro and in vivo models, motivated by the observation that its long-standing antidiabetic, anti-inflammatory, and antioxidant uses lacked empirical evidence of either efficacy or toxicity 41720414Feb.

carotenoid work provides one of the clearest cautionary findings in this set. UV-irradiated liposomes loaded separately with lycopene, phytoene, and phytofluene were assayed by thiobarbituric acid coupled with HPLC-DAD, using malondialdehyde as the lipid oxidation biomarker. Phytoene conferred protection of 27–34% under UV-C and UV-B, comparable to lycopene, but showed no effect under UV-A, where lycopene was the strongest protectant. Phytofluene was purely pro-oxidative: only 13% remained after UV-B and it degraded completely under UV-A, attributed to instability in the presence of oxygen and a high proportion of cis-isomers 42162221May. The result illustrates that compounds grouped as antioxidants by class can invert in behavior depending on the wavelength and oxygen environment.

Targeted delivery was addressed through a nanozyme platform for LPS-induced encephalitis, in which oxidative stress and inflammatory signaling are triggered together. Cerium-doped carbon quantum dots (S2P@Ce-CQDs) were designed with an ultrasmall size for blood–brain barrier penetration and intrinsic fluorescence for treatment tracking, while Ce doping conferred dual superoxide dismutase- and catalase-mimetic activity to scavenge excess reactive oxygen species. A surface S2P targeting peptide directed accumulation to M1 macrophages at the lesion, and the platform both reduced oxidative stress damage and shifted macrophage polarization, reshaping the neuroinflammatory microenvironment 42138488May.

Two reviews place antioxidants within broader therapeutic frameworks. In diabetic kidney disease, mitochondrial dysfunction—excess mitochondrial reactive oxygen species production, reduced biogenesis, impaired mitophagy, and disturbed mitochondrial dynamics—precedes proteinuria and morphological change, and mitochondria-targeted antioxidants are discussed alongside CD38 inhibitors, SGLT2 inhibitors, and traditional Chinese medicine-derived compounds that have shown benefit in animal studies or clinical trials, with the limitations of existing preclinical models explicitly noted 41633353Feb. In dermatology, an integrative "In and Out" model pairs topical retinoids, peptides, antioxidants, and exosome-based formulations with internal nutraceuticals including NAD+ precursors, collagen peptides, polyphenols, and microbiome modulators, targeting oxidative stress, inflammation, and epigenetic change as hallmarks of skin aging; skin aging clocks, biomarker-driven personalization, and artificial intelligence-guided interventions are proposed as tools for individualizing such regimens 41926038Apr.