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•Polystyrene microplastics could enter into the ovary of rat.•Polystyrene microplastics cause ovary fibrosis via Wnt/β-Catenin signaling pathway.•Polystyrene microplastics cause ...granulosa cells apoptosis of ovary.•Polystyrene microplastics could result in decrease of ovarian reserve capacity.
Microplastics (MPs) are receiving increased attention as a harmful environmental pollutant. Studies have investigated that MPs have reproductive toxicity, but the mechanism is little known. Here, we aimed to investigate the effects of polystyrene microplastics (PS-MPs) on ovary in rats and the underlying molecular mechanisms. in vivo, thirty-two female Wistar rats were exposed to 0.5 μm PS-MPs at different concentrations (0, 0.015, 0.15 and 1.5 mg/d) for 90 days. And then, all animals were sacrificed, ovaries and blood were collected for testing. in vitro, granulosa cells (GCs) were separated from rat ovary and treated with 0、1、5、25 μg/mL PS-MPs and reactive oxygen species (ROS) inhibitor N-Acetyl-l-cysteine (NAC) respectively. Our results showed that PS-MPs could enter into GCs and result in the reducing of growing follicles number. And the Enzyme-linked immunosorbent assay (ELISA) manifested that PS-MPs could obviously decrease the level of anti-Müllerian hormone (AMH). In addition, PS-MPs induced oxidative stress, apoptosis of GCs and ovary fibrosis evidenced by assay kits, flow cytometry, immunohistochemistry, Masson’s trichrome and Sirius red staining. Moreover, the western blot assay manifested that PS-MPs exposure significantly increased the expression levels of Wnt/β-Catenin signaling pathways-related proteins (Wnt, β-catenin, p-β-catenin) and the main fibrosis markers (transforming growth factor-β (TGF-β), fibronectin, α-smooth muscle actin (α-SMA). Additionally, the expression levels of Wnt and p-β-catenin, apoptosis of GCs decreased after NAC treatment. In summary, polystyrene microplastics cause fibrosis via Wnt/β-Catenin signaling pathway activation and granulosa cells apoptosis of ovary through oxidative stress in rats, both of which ultimately resulted in decrease of ovarian reserve capacity.
The global burden of neurodegenerative disorders has increased substantially over the past 2 decades due to rising rates of population aging. Although neurodegenerative disorders differ in their ...clinical presentation, the underlying pathobiological processes are largely shared. Oxidative stress, among other mechanisms, is strongly implicated in neurodegenerative disorders and aging, and can potentially be targeted by antioxidative agents. Curcumin, a component of turmeric, is a compound that has received considerable attention for its therapeutic properties, and it is considered to be a powerful antioxidant. In this review, we analyzed the evidence for curcumin as an antioxidant in models of neurodegenerative disorders as well as oxido-nitrosative stress. A total of 1451 articles were found from 3 scientific literature databases (PubMed, Scopus, and Web of Science). After all exclusions, a final total of 64 articles were included in this review. The majority of the studies showed that curcumin, or derivatives thereof, were protective against oxidative and/or nitrosative stress in various cellular and animal models. Overall, curcumin protected against lipid and protein oxidation with a reduction in levels of malondialdehyde, and protein carbonyls, thiols and nitrotyrosines. Furthermore, it stimulated the activities of antioxidant enzymes such as superoxide dismutase and glutathione peroxidase. In conclusion, curcumin appears to be a promising compound for phytomedicine. However, due to some concerns about its efficacy, further targeted experiments are needed to identify its exact molecular targets and pathways responsible for its antioxidant effects.
•64 relevant articles were found in animal and cellular models of neurodegeneration, aging and oxido-nitrosative stress.•The majority of studies showed curcumin alleviated oxidative stress under a wide range of experimental conditions.•Curcumin inhibited lipid and protein oxidation by suppressing malondialdehyde and protein carbonyls.•Curcumin stimulated the activities of various antioxidant enzymes, including superoxide dismutase and catalase.
Purpose of Review
Atherosclerosis is now considered a chronic inflammatory disease. Oxidative stress induced by generation of excess reactive oxygen species has emerged as a critical, final common ...mechanism in atherosclerosis. Reactive oxygen species (ROS) are a group of small reactive molecules that play critical roles in the regulation of various cell functions and biological processes. Although essential for vascular homeostasis, uncontrolled production of ROS is implicated in vascular injury. Endogenous anti-oxidants function as checkpoints to avoid these untoward consequences of ROS, and an imbalance in the oxidant/anti-oxidant mechanisms leads to a state of oxidative stress. In this review, we discuss the role of ROS and anti-oxidant mechanisms in the development and progression of atherosclerosis, the role of oxidized low-density lipoprotein cholesterol, and highlight potential anti-oxidant therapeutic strategies relevant to atherosclerosis.
Recent Findings
There is growing evidence on how traditional risk factors translate into oxidative stress and contribute to atherosclerosis. Clinical trials evaluating anti-oxidant supplements had failed to improve atherosclerosis. Current studies focus on newer ROS scavengers that specifically target mitochondrial ROS, newer nanotechnology-based drug delivery systems, gene therapies, and anti-miRNAs. Synthetic LOX-1 modulators that inhibit the effects of Ox-LDL are currently in development.
Summary
Research over the past few decades has led to identification of multiple ROS generating systems that could potentially be modulated in atherosclerosis. Therapeutic approaches currently being used for atheroslcerotic vascular disease such as aspirin, statins, and renin-angiotensin system inhibitors exert a pleiotropic antioxidative effects. There is ongoing research to identify novel therapeutic modalities to selectively target oxidative stress in atherosclerosis.
Daphenylline is a structurally unique member of the triterpenoid
natural alkaloids, which exhibit intriguing biological activities. Six total syntheses have been reported, five of which utilize ...aromatization approaches. Herein, we report a concise protecting-group-free total synthesis by means of a novel intramolecular oxidative dearomatization reaction, which concurrently generates the critical seven-membered ring and the quaternary-containing vicinal stereocenters. Other notable transformations include a tandem reductive amination/amidation double cyclization reaction, to assemble the cage-like architecture, and installation of the other two chiral stereocenters via a highly enantioselective rhodium-catalyzed challenging hydrogenation of the diene intermediate (90% e.e.) and an unprecedented remote acid-directed Mukaiyama-Michael reaction of the complex benzofused cyclohexanone (13:1 d.r.).
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