Antioxidants最新文献

Hypoxic damage to retinal pigment epithelial (RPE) cells and subsequent neovascularization are key factors in the pathogenesis of branch retinal vein occlusion (BRVO). Naringin (NG), a naturally occurring flavanone glycoside, has demonstrated significant antioxidant and anti-neovascular activities. However, the regulatory effects and mechanisms of NG on ferroptosis in BRVO are yet to be explored. Our study aimed to investigate the protective effects of NG on RPE cells under hypoxic stress and to elucidate the underlying molecular mechanisms. Our findings revealed that NG significantly reduced cytotoxicity induced by cobaltous chloride (CoCl₂) and also inhibited vascular proliferation in the retina, thereby attenuating choroidal neovascularization. NG pretreatment largely countered the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA) triggered by hypoxic damage, while also restoring levels of the antioxidants glutathione (GSH) and superoxide dismutase (SOD). Furthermore, NG pretreatment significantly activated the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and its downstream heme oxygenase-1 (HO-1) and NADPH dehydrogenase (NQO1). In conclusion, NG not only inhibits neovascularization but also alleviates inflammation in RPE cells by modulating the HO-1/GPX4 pathway to inhibit ferroptosis. These findings highlight the potential of NG as a promising therapeutic agent for the treatment of BRVO.

(1) Background: Bovine colostrum (BC) is the initial milk produced by cows after giving birth and has revealed significant potential in helping various health conditions, particularly in diseases of the gastrointestinal tract, such as inflammatory bowel disease, including colitis. BC is renowned for its rich composition of components that strengthen the immune system. Inflammatory bowel diseases, including colitis, are characterized by elevated oxidative stress, leading to tissue damage and exacerbated symptoms. The aim of this study was to explore the potential antioxidant activity of bovine colostrum in the context of a mouse model of trinitrobenzene sulfonic acid-induced colitis. The effectiveness of BC in mitigating oxidative stress and its effects on colitis was evaluated. (2) Methods: Mice were divided into two groups, one group received BC by gavage for 21 days, the other group received saline solution; after 21 days one half of each of the two groups of mice were treated intrarectally with trinitrobenzene sulfonic acid to induce colitis. Colon samples were processed by immunocytochemical methods. The immunoreactivity of the main antioxidant enzymes, (i) catalase (CAT), (ii) superoxide dismutase 1 (SOD1), (iii) superoxide dismutase 2 (SOD2) and glutathione peroxidase 4 (GPX4), at the colon level was analyzed. (3) Results: The results showed positive immunoreactivity of catalase and SOD2 activities of BC in the colon of animals after induction of inflammation. (4) Conclusions: The findings have the potential to suggest new strategies for the management of gastrointestinal disorders related to oxidative stress. Furthermore, the knowledge gained could contribute to the development of functional foods or supplements specifically designed for the management of colitis. Future studies will be aimed at identifying the bioactive fractions of BC to study the mechanisms underlying its actions, as well as to trace which populations can benefit most from colostrum consumption, in addition to subjects with gastrointestinal disorders.

With the continued exploration of the universe, there is an increasingly urgent need to address the health challenges arising from spaceflight. In space, astronauts are exposed to radiation, confinement and isolation, circadian rhythm dysregulation, and microgravity conditions that are different from those on Earth. These risk factors jeopardize astronauts' health, thus affecting the quality of space missions. Among these factors, gravitational changes influence the balance between oxidation and antioxidants, stimulating the production of reactive oxygen species (ROS), finally leading to oxidative stress (OS). OS leads to oxidative damage of biomolecules such as lipids, proteins, and DNA, which causes the development of various diseases. The occurrence of OS is increased in microgravity and affects multiple systems, including the musculoskeletal, cardiovascular, nervous, and immune systems. In this review, we discuss the mechanisms of OS, the physiological effects on different systems caused by OS in microgravity environment, and potential treatments for OS. Finally, treatment strategies for oxidative stress in microgravity are summarized, providing some promising approaches for protecting the health of astronauts in future space exploration.

Grafting is a horticultural technique that involves a healing process that requires grafted plants to develop physiological responses to overcome oxidative stress. In this study, oxidative damage, total antioxidant capacity and antioxidant enzymatic activities were analysed in functional and non-functional tomato autografts for eight days after grafting, considering scion and rootstock tissues separately. The results showed that oxidative damage, measured as lipid peroxidation, was controlled, especially in functional grafts. Scion tissues showed significant increases in total antioxidant capacity and activities of key antioxidant enzymes, including superoxide dismutase and catalase. Non-functional grafts showed elevated levels of class III peroxidase, potentially related to defensive suberisation and lignification. Principal component analysis revealed that antioxidant activities correlated dynamically with grafting stages, highlighting their critical role in stress mitigation. These results suggest that an efficient and asymmetric antioxidant response is essential for successful graft healing in tomato plants. Furthermore, different patterns in non-functional grafts underline the importance of redox balance in determining graft success.

Black soybeans have numerous health benefits owing to their high polyphenolic content, antioxidant activity, and antitumor effects. We previously reported that the Korean black soybean cultivar 'Soman' possesses higher anthocyanin and isoflavone contents and superior antioxidant potential than other Korean black soybean cultivars and landraces (Seoritae) do. Here, we investigated and compared the antitumor effects of Soman and Seoritae and aimed to elucidate the possible mechanisms of action. Soman inhibited cancer cell proliferation and was more potent than Seoritae. Mechanistically, Soman inhibited the phosphorylation of the signal transducer and activator of transcription (STAT1, 3, and 5) in a reactive oxygen species (ROS)-independent manner, subsequently decreasing glycolytic enzyme expression and the activities of pyruvate kinase and lactate dehydrogenase. Thus, Soman suppressed glucose uptake, lactate production, and ATP production in cancer cells. Additionally, it inhibited tumor growth in a B16F10 murine melanoma syngeneic model, accompanied by reduced STAT1 phosphorylation and decreased proliferation in Soman-treated mice, more potently than observed in Seoritae-treated mice. These findings showed that Soman exerted superior antitumor activities by suppressing STAT-mediated aerobic glycolysis and proliferation. Overall, our findings demonstrate the potent, tumor-suppressive role of Soman in human cancer and uncover a novel molecular mechanism for its therapeutic effects in cancer treatment.

Hydrogen peroxide (H₂O₂) plays a crucial role in cell signaling in response to physiological and environmental perturbations. H₂O₂ can oxidize typical 2-Cys peroxiredoxin (PRX) first into a sulfenic acid, which resolves into a disulfide that can be reduced by thioredoxin (TRX)/TRX reductase (TR). At high levels, H₂O₂ can also hyperoxidize sulfenylated PRX into a sulfinic acid that can be reduced by sulfiredoxin (SRX). Therefore, PRX, TRX, TR, and SRX (abbreviated as PTRS system here) constitute the coupled sulfenylation and sulfinylation cycle (CSSC), where certain oxidized PRX and TRX forms also function as redox signaling intermediates. Earlier studies have revealed that the PTRS system is capable of rich signaling dynamics, including linearity, ultrasensitivity/switch-like response, nonmonotonicity, circadian oscillation, and possibly, bistability. However, the origins of ultrasensitivity, which is fundamentally required for redox signal amplification, have not been adequately characterized, and their roles in enabling complex nonlinear dynamics of the PTRS system remain to be determined. Through in-depth mathematical modeling analyses, here we revealed multiple sources of ultrasensitivity that are intrinsic to the CSSC, including zero-order kinetic cycles, multistep H₂O₂ signaling, and a mechanism arising from diminished H₂O₂ removal at high PRX hyperoxidation state. The CSSC, structurally a positive feedback loop, is capable of bistability under certain parameter conditions, which requires embedding multiple sources of ultrasensitivity identified. Forming a negative feedback loop with cytosolic SRX as previously observed in energetically active cells, the mitochondrial PTRS system (where PRX3 is expressed) can produce sustained circadian oscillations through supercritical Hopf bifurcations. In conclusion, our study provided novel quantitative insights into the dynamical complexity of the PTRS system and improved appreciation of intracellular redox signaling.

Stallion spermatozoa are cells which exhibit intense metabolic activity, where oxidative phosphorylation in the mitochondria is the primary ATP generator. However, metabolism must be viewed as a highly interconnected network of oxidation-reduction reactions that generate the energy necessary for life. An unavoidable side effect of metabolism is the generation of reactive oxygen species, leading to the evolution of sophisticated mechanisms to maintain redox homeostasis. In this paper, we provide an updated overview of glucose metabolism in stallion spermatozoa, highlighting recent evidence on the role of aerobic glycolysis in these cells, and the existence of an intracellular lactate shuttle that may help to explain the particular metabolism of the stallion spermatozoa in the context of their redox regulation.

In the original publication [...].

Anthocyanins (ANTHs) are polyphenolic compounds with health promoting properties, being known for their strong antioxidant effects as well as for their antimicrobial properties, obesity and cardiovascular disease prevention, and anticarcinogenic activity. Being main dietary components, it is important to know the content of anthocyanins in various dietary sources and their stability in time. The total anthocyanin content (TAC) of various fresh fruits has been spectrophotometrically determined using the pH differential method. The results showed that in the analyzed samples, the TAC increased in the order: blackcurrants > blackberries > blueberries > raspberries > strawberries > plums. The degradation degree of anthocyanins extracted from blueberries (BBEs) in an ethanol/water solution in four experimental conditions was studied. Kinetic studies have been approached, fitting the experimental data recorded by UV-Vis spectrophotometric analysis in agreement with some kinetic models verified for the ANTH degradation reaction. Therefore, zero-order kinetics for BBE extract degradation exposed to sunlight were identified, while for the other storage conditions (shadow, dark, cold), the first-order kinetics were respected. The results indicate that the stability decreased as follows: (ANTH stability)_{sunlight test} << (ANTH stability)_{shadow test} ≈ (ANTH stability)_{dark test} < (ANTH stability)_{cold test}. A mechanism for BBE anthocyanin degradation was proposed and the impact on human health of the degradation products is discussed.

The cryopreservation of oocytes through vitrification is imperative for the conservation of livestock germplasm resources. However, as oocytes exhibit significant oxidative stress and organelle damage following vitrification freezing, it is crucial to optimise the vitrification conditions to mitigate the deleterious effects of freezing. In this study, we demonstrated that spermidine has been showed to enhance oocyte survival after vitrification freezing (92% ± 4% vs. 82% ± 3%, p < 0.01) and blastocyst formation after freezing for in vitro fertilisation (14.86% ± 7% vs. 6% ± 3, p < 0.05). Spermidine supplementation rescued 47.3% of dysregulated pathways, including ovarian steroidogenesis, and restored normal expression levels in 43.3% of aberrantly expressed genes. Subsequent studies elucidated that spermidine effectively rescued mitochondrial dysfunction after vitrification, alleviated oxidative stress damage, and regulated intracellular calcium homeostasis. Consequently, we concluded that the addition of spermidine during vitrification freezing is an effective method to protect oocytes from freezing damage.