Astragaloside IV Attenuates Experimental Autoimmune Encephalomyelitis of Mice by Counteracting Oxidative Stress at Multiple Levels

ObjectiveProgressive multiple sclerosis is characterized by chronic inflammation with microglial activation, oxidative stress, accumulation of iron and continuous neurodegeneration with inadequate effectiveness of medications used so far. We now investigated effects of iron on microglia and used the previously identified neuroprotective antipsychotic clozapine in vitro and in chronic experimental autoimmune encephalomyelitis (EAE).MethodsMicroglia were treated with iron and clozapine followed by analysis of cell death and response to oxidative stress, cytokine release and neuronal phagocytosis. Clozapine was investigated in chronic EAE regarding optimal dosing and therapeutic effectiveness in different treatment paradigms. Animals were scored clinically by blinded raters. Spinal cords were analyzed histologically for inflammation, demyelination, microglial activation and iron accumulation and for transcription changes of regulators of iron metabolism and inflammation. Effects on immune cells were analyzed using flow cytometry.ResultsIron impaired microglial function in vitro regarding phagocytosis and markers of inflammation; this was regulated by clozapine, reflected in reduced release of IL-6 and normalization of neuronal phagocytosis. In chronic EAE, clozapine dose-dependently attenuated clinical signs and still had an effect if applied in a therapeutic setting. Early mild sedative effects habituated over time. Histologically, demyelination was reduced by clozapine and positive effects on inflammation strongly correlated with reduced iron deposition. This was accompanied by reduced expression of DMT-1, an iron transport protein.ConclusionsClozapine regulates microglial function and attenuates chronic EAE, even in a therapeutic treatment paradigm. This well-defined generic medication might therefore be considered as promising add-on therapeutic for further development in progressive MS.

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The Function of the Hypothalamic–Pituitary–Adrenal Axis During Experimental Autoimmune Encephalomyelitis: Involvement of Oxidative Stress Mediators

Frontiers in Neuroscience ◽

10.3389/fnins.2021.649485 ◽

2021 ◽

Vol 15 ◽

Author(s):

Svetlana Trifunovic ◽

Ivana Stevanovic ◽

Ana Milosevic ◽

Natasa Ristic ◽

Marija Janjic ◽

...

Keyword(s):

Oxidative Stress ◽

Experimental Autoimmune Encephalomyelitis ◽

Hpa Axis ◽

Superoxide Anion ◽

Adrenal Glands ◽

Demyelinating Disease ◽

Unknown Origin ◽

Autoimmune Encephalomyelitis ◽

Hypothalamic Pituitary Adrenal ◽

Experimental Autoimmune

Multiple sclerosis (MS) is an inflammatory, demyelinating disease with an unknown origin. Previous studies showed the involvement of the hypothalamic–pituitary–adrenal (HPA) axis to susceptibility to autoimmune diseases, including MS, and its best-characterized animal model, experimental autoimmune encephalomyelitis (EAE). During MS/EAE, innate immune cells are activated and release cytokines and other inflammatory mediators, leading to a vicious cycle of inflammation. In response to inflammation, the activated HPA axis modulates immune responses via glucocorticoid activity. Because the mechanisms involving oxidative stress to the HPA axis are relatively unrevealed, in this study, we investigate the inflammatory and oxidative stress status of HPA axis during EAE. Our results reveal an upregulation of Pomc gene expression, followed by POMC and ACTH protein increase at the peak of the EAE in the pituitary. Also, prostaglandins are well-known contributors of HPA axis activation, which increases during EAE at the periphery. The upregulated Tnf expression in the pituitary during the peak of EAE occurred. This leads to the activation of oxidative pathways, followed by upregulation of inducible NO synthase expression. The reactive oxidant/nitrosative species (ROS/RNS), such as superoxide anion and NO, increase their levels at the onset and peak of the disease in the pituitary and adrenal glands, returning to control levels at the end of EAE. The corticotrophs in the pituitary increased in number and volume at the peak of EAE that coincides with high lipid peroxidation levels. The expression of MC2R in the adrenal glands increases at the peak of EAE, where strong induction of superoxide anion and malondialdehyde (MDA), reduced total glutathione (GSH) content, and catalase activity occurred at the peak and end of EAE compared with controls. The results obtained from this study may help in understanding the mechanisms and possible pharmacological modulation in MS and demonstrate an effect of oxidative stress exposure in the HPA activation during the course of EAE.

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Astragaloside IV regulates differentiation and induces apoptosis of activated CD4+ T cells in the pathogenesis of experimental autoimmune encephalomyelitis

Toxicology and Applied Pharmacology ◽

10.1016/j.taap.2018.10.024 ◽

2019 ◽

Vol 362 ◽

pp. 105-115 ◽

Cited By ~ 9

Author(s):

Liu Yang ◽

Faping Xing ◽

Xinyan Han ◽

Qi Li ◽

Hui Wu ◽

...

Keyword(s):

T Cells ◽

Experimental Autoimmune Encephalomyelitis ◽

Cd4 T Cells ◽

Astragaloside Iv ◽

Autoimmune Encephalomyelitis ◽

Experimental Autoimmune

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P-glycoprotein Inhibitor Tariquidar Potentiates Efficacy of Astragaloside IV in Experimental Autoimmune Encephalomyelitis Mice

Molecules ◽

10.3390/molecules24030561 ◽

2019 ◽

Vol 24 (3) ◽

pp. 561 ◽

Cited By ~ 7

Author(s):

Wei Zhang ◽

Mei Liu ◽

Liu Yang ◽

Fei Huang ◽

Yunyi Lan ◽

...

Keyword(s):

Experimental Autoimmune Encephalomyelitis ◽

Drug Efficacy ◽

Microvascular Endothelial Cell ◽

Cancer Resistance ◽

Astragaloside Iv ◽

Autoimmune Encephalomyelitis ◽

Inflammatory Infiltration ◽

P Glycoprotein ◽

Microvascular Endothelial ◽

Experimental Autoimmune

ATP-binding cassette (ABC) transporters, such as P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), often reduce drug efficacy and are the major cause of drug resistance. Astragaloside IV (ASIV), one of the bioactive saponins isolated from Astragalus membranaceus, has been demonstrated to alleviate the progression of experimental autoimmune encephalomyelitis (EAE) in mice, an animal model for multiple sclerosis (MS). In the present study, we found for the first time that ASIV induced the upregulation of P-gp and BCRP in the central nervous system (CNS) microvascular endothelial cells of EAE mice. Further study disclosed that tariquidar, a P-gp inhibitor, could facilitate the penetration of ASIV into CNS. On bEnd.3 cells, a mouse brain microvascular endothelial cell line, tariquidar benefited the net uptake and transport of ASIV. Additional molecular docking experiment suggested that ASIV might be a potential substrate of P-gp. In EAE mice, tariquidar was demonstrated to enhance the efficacy of ASIV, as shown by attenuated clinical symptom and reduced incidence rate as well as mitigated inflammatory infiltration and decreased demyelination in the CNS. Collectively, our findings implicate that P-gp inhibitor can promote the therapeutic efficacy of ASIV on EAE mice, which may boost its clinical usage together with ASIV in the therapy of MS.

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Extra-Virgin Olive Oil Modifies the Changes Induced in Non-Nervous Organs and Tissues by Experimental Autoimmune Encephalomyelitis Models

Nutrients ◽

10.3390/nu11102448 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2448 ◽

Cited By ~ 3

Author(s):

Cristina Conde ◽

Begoña M. Escribano ◽

Evelio Luque ◽

Montserrat Feijóo ◽

Javier Caballero-Villarraso ◽

...

Keyword(s):

Oxidative Stress ◽

Experimental Autoimmune Encephalomyelitis ◽

Oxidative Damage ◽

Olive Oil ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Male Rats ◽

Dark Agouti ◽

Autoimmune Encephalomyelitis ◽

Experimental Autoimmune

This study reveals the existence of oxidative stress (reactive oxygen species (ROS)) in non-nervous organs and tissues in multiple sclerosis (MS) by means of a model of experimental autoimmune encephalomyelitis (EAE) in rats. This model reproduces a similar situation to MS, as well as its relationship with intestinal microbiota starting from the changes in bacterial lipopolysaccharide levels (LPS) in the outer wall of the gram-negative bacteria. Finally, the administration of extra-virgin olive oil (EVOO), hydroxytirosol (HT), and oleic acid (OA) exert beneficial effects. Twenty-five Dark Agouti two-month-old male rats, weighing around 190 g, were distributed into the following groups: Control, EAE (experimental autoimmune encephalomyelitis group), EAE + EVOO, EAE + HT, and EAE + OA. The glutathione redox system with the EAE was measured in heart, kidney, liver, and small and large intestines. The LPS and the correlation with oxidative stress in the small and large intestines were also investigated. The results showed that (1) the oxidative damage in the EAE model affects non-nervous organs and tissues; (2) The LPS is related to inflammatory phenomena and oxidative stress in the intestinal tissue and in other organs; (3) The administration of EVOO, HT, and OA reduces the LPS levels at the same time as minimizing the oxidative damage; (4) EVOO, HT, and OA improve the disease’s clinical score; and (5) on balance, EVOO offers a better neuroprotective effect.

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