Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder and is triggered via abnormal accumulation of amyloid-β peptide (Aβ). Aggregated Aβ is responsible for disrupting calcium homeostasis, inducing neuroinflammation, and promoting neurodegeneration. In this study, we generated curcuminoid submicron particle (CSP), which reduce the average size to ~60 nm in diameter. CSP had elevated the bioavailability in vivo and better neuroprotective effect against oligomeric Aβ than un-nanosized curcuminoids in vitro. Two months of CSP consumption reversed spatial memory deficits and the loss of a calcium binding protein calbindin-D28k in the hippocampus of AD mouse model. In addition, CSP consumption lowered amyloid plaques and astrogliosis in vivo and enhanced microglial Aβ phagocytosis in vitro, implying that the beneficial effects of CSP also mediated via modulating neuroinflammation and enhancing amyloid clearance. Taken together, our study demonstrated the protective effects of CSP toward ameliorating the memory impairment and pathological deficits in AD mouse model.
In the present study, the neuroprotective effect of melatonin on arsenite-induced neurotoxicity was investigated in rat primary cultured cortical neurons. Incubation of melatonin prevented arsenite-induced neuronal cell loss in a concentration-dependent manner. Furthermore, melatonin significantly attenuated arsenite-induced elevation in microtubule-associated protein light chain 3 (LC3)-II levels, a biomarker of autophagy. Our fluorescent staining assay showed that melatonin decreased arsenite-induced elevation of co-localized fluorescent puncta of monodansylcadaverine (a specific marker of autophagic vacuoles) and lysotracker red (a specific marker of lysosomes), indicating that melatonin is capable of inhibiting arsenite-induced autophagy and autolysosome formation. Because 3-methyladenine (an autophagic inhibitor) attenuated the arsenite-reduced α-synuclein levels (a protein essential for the neurite outgrowth and synaptic plasticity), melatonin via inhibiting autophagy attenuated the arsenite-reduced α-synuclein levels. At the same time, melatonin ameliorated the arsenite-induced reduction in growth associated protein 43 (a hallmark protein of neurite outgrowth) and discontinuous neurites of rat primary cultured cortical neurons. In addition, melatonin was found to prevent arsenite-induced decreases in cytochrome c oxidase levels (a biomarker of mitochondrial mass) and elevation in co-localized fluorescent puncta of autolysosomes and cytochrome c oxidase. Moreover, melatonin prevented arsenite-induced reduction in peroxisome proliferator-activated receptor gamma co-activator 1 α, a transcriptional co-activator of mitochondrial biosynthesis. Taken together, melatonin may exert its neuroprotective action via inhibiting arsenite-induced autophagy and enhancing mitochondrial biogenesis and thus restoring α-synuclein levels, neuronal integrity, and mitochondrial mass in rat primary cultured cortical neurons.
In the present study, the role of heme oxygenase (HO)-1 in sodium arsenite (arsenite)-induced neurotoxicity was investigated using primary cultured cortical neurons. Incubation with arsenite was found to cause cell death of primary cultured cortical neurons in concentration- and time-dependent manners. Furthermore, arsenite induced caspase 3 activation and decreased procaspase 12 levels, indicating that apoptosis is involved in the arsenite-induced neurotoxicity. The oxidative mechanism underlying arsenite-induced neurotoxicity was investigated. Western blot assay showed that arsenite significantly increased HO-1 levels, a redox-regulated protein. Co-incubation with glutathione (10 mM) attenuated arsenite-induced HO-1 elevation and caspase 3 activation, suggesting that oxidative stress is involved in the arsenite-induced neurotoxicity. The neurotoxic effects of inorganic arsenics were compared; arsenite was more potent than arsenate in inducing HO-1 expression and caspase 3 activation. Moreover, the cell viabilities of arsenite and arsenate were 60 ± 2 and 99 ± 2 % of control, respectively. HO-1 siRNA transfection was employed to prevent arsenite-induced HO-1 elevation. At the same time, arsenite-induced caspase 3 activation and neuronal death were attenuated in the HO-1 siRNA-transfected cells. Taken together, HO-1 appears to be neuroprotective in the arsenite-induced neurotoxicity in primary cultured cortical neurons. In addition to antioxidants, HO-1 elevation may be a neuroprotective strategy for arsenite-induced neurotoxicity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.