Magnesium-L-threonate alleviate colonic inflammation and memory impairment in chronic-plus-binge alcohol feeding mice

Magnesium-L-threonate treats Alzheimer's disease by modulating the microbiota-gut-brain axis

JOURNAL/nrgr/04.03/01300535-202410000-00029/figure1/v/2024-02-06T055622Z/r/image-tiff Disturbances in the microbiota-gut-brain axis may contribute to the development of Alzheimer's disease. Magnesium-L-threonate has recently been found to have protective effects on learning and memory in aged and Alzheimer's disease model mice. However, the effects of magnesium-L-threonate on the gut microbiota in Alzheimer's disease remain unknown. Previously, we reported that magnesium-L-threonate treatment improved cognition and reduced oxidative stress and inflammation in a double-transgenic line of Alzheimer's disease model mice expressing the amyloid-β precursor protein and mutant human presenilin 1 (APP/PS1). Here, we performed 16S rRNA amplicon sequencing and liquid chromatography-mass spectrometry to analyze changes in the microbiome and serum metabolome following magnesium-L-threonate exposure in a similar mouse model. Magnesium-L-threonate modulated the abundance of three genera in the gut microbiota, decreasing Allobaculum and increasing Bifidobacterium and Turicibacter. We also found that differential metabolites in the magnesium-L-threonate-regulated serum were enriched in various pathways associated with neurodegenerative diseases. The western blotting detection on intestinal tight junction proteins (zona occludens 1, occludin, and claudin-5) showed that magnesium-L-threonate repaired the intestinal barrier dysfunction of APP/PS1 mice. These findings suggest that magnesium-L-threonate may reduce the clinical manifestations of Alzheimer's disease through the microbiota-gut-brain axis in model mice, providing an experimental basis for the clinical treatment of Alzheimer's disease.

Effects of long-term magnesium L-threonate supplementation on neuroinflammation, demyelination and blood-brain barrier integrity in mice with neuromyelitis optica spectrum disorder

In clinical practice, we found cerebrospinal fluid magnesium concentration significantly lower in neuromyelitis optica spectrum disorder (NMOSD) patients compared to controls with non-autoimmune encephalitis neurological diseases. To investigate the effects and potential mechanisms of long-term magnesium supplementation on neuroinflammation, demyelination, and blood-brain barrier (BBB) integrity in NMOSD, we used two models: (1) NMOSD mouse model, which was induced by intraperitoneal injection of purified NMO-IgG to experimental autoimmune encephalomyelitis (EAE) mice, and (2) cultured human cerebral microvascular endothelial cells/D3 (hCMEC/D3). In the NMOSD mouse model, Magnesium L-threonate (MgT) pretreatment alleviated NMO-IgG-induced effects, including AQP4 loss, leukocyte infiltration, astrocyte and microglia activation, demyelination, decreased tight junction (TJ) protein expression, and neurological deficits. In vitro, MgT pretreatment ameliorated NMO-IgG induced damage to TJ protein expression in a (transient receptor potential melastatin 7) TRPM7-dependent manner. Magnesium supplementation shows potential protective effects against NMOSD, suggesting it may be a novel therapeutic approach for this condition. The beneficial effects appear to be mediated through preservation of blood-brain barrier integrity and reduction of neuroinflammation and demyelination.

Tongfu Lifei Decoction Attenuated Sepsis-Related Intestinal Mucosal Injury Through Regulating Th17/Treg Balance and Modulating Gut Microbiota

Intestinal damage and secondary bacterial translocation are caused by the inflammatory response induced by sepsis. Tongfu Lifei (TLF) decoction has a protective effect on sepsis-related gastrointestinal function injury. However, the relation between gut microbiota, immune barrier, and sepsis under the treatment of TLF have not been well clarified yet. Here, rats were subjected to cecal ligation and puncture (CLP) to create a sepsis model. Subsequently, the TLF decoction was given to CLP rats by gavage, fecal microbiota transplantation (FMT), and antibiotic were used as positive control. TLF suppressed the inflammatory response and improved the pathological changes in the intestines of CLP rats. Besides, TLF promoted the balance of the percentage of the Th17 and Treg cells. Intestinal barrier function was also improved by TLF through enhancing ZO-1, and Occludin and Claudin 1 expression, preventing the secondary translocation of other gut microbiota. TLF dramatically boosted the gut microbiota's alpha- and beta-diversity in CLP rats. Moreover, it increased the relative abundance of anti-inflammatory gut microbiota and changed the progress of the glucose metabolism. In short, TLF regulated the gut microbiota to balance the ratio of Th17/Treg cells, reducing the inflammation in serum and intestinal mucosal injury in rats.

Akkermansia muciniphila and Alcohol-Related Liver Diseases. A Systematic Review

SCOPE

Akkermansia muciniphila (A. muciniphila) are Gram negative commensal bacteria, degrading mucin in the intestinal mucosa, modulating intestinal permeability and inflammation in the digestive tract, liver, and blood. Some components can promote the relative abundance of A. muciniphila in the gut microbiota, but lower levels of A. muciniphila are more commonly found in people with obesity, diabetes, metabolic syndromes, or inflammatory digestive diseases. Over-intake of ethanol can also induce a decrease of A. muciniphila, associated with dysregulation of microbial metabolite production, impaired intestinal permeability, induction of chronic inflammation, and production of cytokines.

METHODS AND RESULTS

Using a PRISMA search strategy, a review is performed on the bacteriological characteristics of A. muciniphila, the factors capable of modulating its relative abundance in the digestive tract and its probiotic use in alcohol-related liver diseases (alcoholic hepatitis, cirrhosis, hepatocellular carcinoma, hepatic transplantation, partial hepatectomy).

CONCLUSION

Several studies have shown that supplementation with A. muciniphila can improve ethanol-related hepatic pathologies, and highlight the interest in using this bacterial species as a probiotic.

Combined resistant dextrin and low-dose Mg oxide administration increases short-chain fatty acid and lactic acid production by gut microbiota

The consumption of resistant dextrin improves constipation, while its fermentation and degradation by the intestinal microbiota produce short-chain fatty acids (SCFA) and lactic acid, which have beneficial effects on host metabolism and immunity. Mg oxide (MgO) is an important mineral that is used to treat constipation. Therefore, resistant dextrin and MgO are often administered together to improve constipation. However, limited information is available regarding the effect of this combination on SCFA and lactic acid production. Crl:CD1(ICR) mice were fed a Mg-free diet with 5% resistant dextrin, followed by oral administration of MgO. We collected the cecum contents and measured SCFA and lactic acid levels. Additionally, the human subjects received resistant dextrin and Mg supplements as part of their habitual diet. The results of this study demonstrate that intestinal microbiota cannot promote SCFA and lactic acid production in the absence of Mg. In a mouse model, low doses of MgO promoted the production of SCFA and lactic acid, whereas high doses decreased their production. In humans, the combined consumption of resistant dextrin and Mg supplements increased the production of SCFA and lactic acid. The production of SCFA and lactic acid from dietary fiber may be augmented by the presence of MgO.

Discovery of metabolic markers for the discrimination of Helwingia species based on bioactivity evaluation, plant metabolomics, and network pharmacology

RATIONALE

Helwingia japonica (HJ), a traditional medicinal plant, is commonly used for the treatment of dysentery, blood in the stool, and scald burns. Three major HJ species, Helwingia japonica (Thunb.) Dietr. (QJY), Helwingia himalaica Hook. f. et Thoms. ex C. B. Clarke, and Helwingia chinensis Batal., share great similarities in both morphology and chemical constituents. The discrimination of medicinal plants directly affects their pharmacological and clinical effects. Here, we solved the taxonomy uncertainty of these three HJ species and explored the discrimination and study of other traditional medicines (TMs).

METHODS

First, the anti-inflammatory effects of the three HJ species were compared using lipopolysaccharide (LPS)-induced inflammatory responses in mouse leukemia cells of monocyte macrophage (RAW) 264.7 cells. Then, plant metabolomics were performed in 48 batches of samples to discover chemical markers for discriminating different HJ species. Finally, network pharmacology was applied to explore the linkages among constituents, targets, and signaling pathways.

RESULTS

In vitro experiments showed that the QJY exhibited the most potential anti-inflammatory activities. Meanwhile, 172 compounds were tentatively identified and eight metabolites with higher relative content in QJY were designated as chemical markers to distinguish QJY and the other two species. According to the property of absorbed in vivo, threonic acid, arginine, and tyrosine were selected to construct a component-target-pathway network. The network pharmacology analysis confirmed that the chemotaxonomy differentiation was consistent with the bioactive assessment.

CONCLUSIONS

The present study demonstrates that bioactivity evaluation integrated with plant metabolomics and network pharmacology could be used as an effective approach to discriminate different TMs and discover the active compounds.

A Mini Review on the Various Facets Effecting Brain Delivery of Magnesium and Its Role in Neurological Disorders

Magnesium is an essential cation present in the body that participates in the regulation of various vital body functions. Maintaining normal level of magnesium is essential for proper brain functions by regulating the activities of numerous neurotransmitters and their receptors. Various studies have been reported that magnesium level is found to be declined in both neurological and psychiatric diseases. Declined magnesium level in the brain initiates various cumbersome effects like excitotoxicity, altered blood-brain permeability, oxidative stress, and inflammation, which may further worsen the disease condition. Shreds of evidence from the experimental and clinical studies proved that exogenous administration of magnesium is useful for correcting disease-induced alterations in the brain. But one of the major limiting factors in the use of magnesium for treatment purposes is its poor blood-brain barrier permeability. Various approaches like the administration of its organic salts as pidolate and threonate forms, and the combination with polyethylene glycol or mannitol have been tried to improve its permeability to make magnesium as a suitable drug for different neurological disorders. These results have shown their experimental efficacy in diseased animal models, but studies regarding the safety and efficacy in human subjects are currently underway. We present a comprehensive review on the role of magnesium in the maintenance of normal functioning of the brain and various approaches for improving its BBB permeability.

Apolipoprotein E knockout may affect cognitive function in D-galactose-induced aging mice through the gut microbiota–brain axis

The gut microbiota plays an important role in central nervous system (CNS) disorders. Apolipoprotein E (ApoE) can affect the composition of the gut microbiota and is closely related to the CNS. However, the mechanism by which ApoE affects cognitive dysfunction through the gut microbiota–brain axis has thus far not been investigated. In this study, we used wild-type mice and ApoE knockout (ApoE^–/–) mice to replicate the aging model and examined the effects of ApoE deletion on cognitive function, hippocampal ultrastructure, synaptophysin (SYP) and postsynaptic density 95 (PSD-95) in aging mice. We also explored whether ApoE deletion affects the gut microbiota and the metabolite profile of the hippocampus in aging mice and finally examined the effect of ApoE deletion on lipids and oxidative stress in aging mice. The results showed that the deletion of ApoE aggravated cognitive dysfunction, hippocampal synaptic ultrastructural damage and dysregulation of SYP and PSD-95 expression in aging mice. Furthermore, ApoE deletion reduced gut microbial makeup in aging mice. Further studies showed that ApoE deletion altered the hippocampal metabolic profile and aggravated dyslipidemia and oxidative stress in aging mice. In brief, our findings suggest that loss of ApoE alters the composition of the gut microbiota, which in turn may affect cognitive function in aging mice through the gut microbiota–brain axis.

Jiedu-Yizhi Formula Alleviates Neuroinflammation in AD Rats by Modulating the Gut Microbiota

Background

The Jiedu-Yizhi formula (JDYZF) is a Chinese herbal prescription used to treat Alzheimer's disease (AD). It was previously confirmed that JDYZF can inhibit the expression of pyroptosis-related proteins in the hippocampus of AD rats and inhibit gut inflammation in AD rats. Therefore, it is hypothesized that JDYZF has a regulatory effect on the gut microbiota.

Methods

In this study, an AD rat model was prepared by bilateral hippocampal injection of Aβ_25-35 and AD rats received high, medium, and low doses of JDYZF orally for 8 weeks. The body weights of the AD rats were observed to assess the effect of JDYZF. The 16S rRNA sequencing technique was used to study the regulation of the gut microbiota by JDYZF in AD rats. Immunohistochemical staining was used to observe the expression levels of Caspase-1 and Caspase-11 in the hippocampus.

Results

JDYZF reduced body weight in AD rats, and this effect may be related to JDYZF regulating body-weight-related gut microbes. The 16S rRNA analysis showed that JDYZF increased the diversity of the gut microbiota in AD rats. At the phylum level, JDYZF increased the abundances of Bacteroidota and Actinobacteriota and decreased the abundances of Firmicutes, Campilobacterota, and Desulfobacterota. At the genus level, the abundances of Lactobacillus, Prevotella, Bacteroides, Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, and Blautia were increased and the abundances of Lachnospiraceae-NK4A136-group, Anaerobiospirillum, Turicibacter, Oscillibacter, Desulfovibrio, Helicobacter, and Intestinimonas were decreased. At the species level, the abundances of Lactobacillus johnsonii, Lactobacillus reuteri, and Lactobacillus faecis were increased and the abundances of Helicobacter rodentium and Ruminococcus_sp_N15.MGS-57 were decreased. Immunohistochemistry showed that JDYZF reduced the levels of Caspase-1- and Caspase-11-positive staining.

Conclusion

JDYZF has a regulatory effect on the gut microbiota of AD rats, which may represent the basis for the anti-inflammatory effect of JDYZF.

Liuwei Dihuang Decoction Alleviates Cognitive Dysfunction in Mice With D-Galactose-Induced Aging by Regulating Lipid Metabolism and Oxidative Stress via the Microbiota-Gut-Brain Axis

Background

Aging is an important cause of cognitive dysfunction. Liuwei Dihuang decoction (LW), a commonly applied Chinese medicine formula, is widely used for the treatment of aging-related diseases in China. Previously, LW was confirmed to be effective in prolonging life span and reducing oxidative stress in aged mice. Unfortunately, the underlying mechanism of LW remains unclear. The aim of this study was to interpret the mechanism by which LW alleviates cognitive dysfunction related to aging from the perspective of the microbiota-gut-brain axis.

Method

All C57BL/6 mice (n = 60) were randomly divided into five groups: the control, model, vitamin E (positive control group), low-dose LW and high-dose LW groups (n = 12 in each group). Except for those in the control group, D-galactose was subcutaneously injected into mice in the other groups to induce the aging model. The antiaging effect of LW was evaluated by the water maze test, electron microscopy, 16S rRNA sequencing, combined LC–MS and GC–MS metabolomics, and ELISA.

Results

Liuwei Dihuang decoction ameliorated cognitive dysfunction and hippocampal synaptic ultrastructure damage in aging mice. Moreover, LW decreased Proteobacteria abundance and increased gut microbiota diversity in aging mice. Metabolomic analysis showed that LW treatment was associated with the significantly differential abundance of 14 metabolites, which were mainly enriched in apelin signaling, sphingolipid metabolism, glycerophospholipid and other metabolic pathways. Additionally, LW affected lipid metabolism and oxidative stress in aging mice. Finally, we also found that LW-regulated microbial species such as Proteobacteria and Fibrobacterota had potential relationships with lipid metabolism, oxidative stress and hippocampal metabolites.

Conclusion

In brief, LW improved cognitive function in aging mice by regulating lipid metabolism and oxidative stress through restoration of the homeostasis of the microbiota-gut-brain axis.

Improvement of synaptic plasticity by nanoparticles and the related mechanisms: Applications and prospects

Synaptic plasticity is an important basis of learning and memory and participates in brain network remodelling after different types of brain injury (such as that caused by neurodegenerative diseases, cerebral ischaemic injury, posttraumatic stress disorder (PTSD), and psychiatric disorders). Therefore, improving synaptic plasticity is particularly important for the treatment of nervous system-related diseases. With the rapid development of nanotechnology, increasing evidence has shown that nanoparticles (NPs) can cross the blood-brain barrier (BBB) in different ways, directly or indirectly act on nerve cells, regulate synaptic plasticity, and ultimately improve nerve function. Therefore, to better elucidate the effect of NPs on synaptic plasticity, we review evidence showing that NPs can improve synaptic plasticity by regulating different influencing factors, such as neurotransmitters, receptors, presynaptic membrane proteins and postsynaptic membrane proteins, and further discuss the possible mechanism by which NPs improve synaptic plasticity. We conclude that NPs can improve synaptic plasticity and restore the function of damaged nerves by inhibiting neuroinflammation and oxidative stress, inducing autophagy, and regulating ion channels on the cell membrane. By reviewing the mechanism by which NPs regulate synaptic plasticity and the applications of NPs for the treatment of neurological diseases, we also propose directions for future research in this field and provide an important reference for follow-up research.

Antioxidant/anti-inflammatory effect of Mg2+ in coronavirus disease 2019 (COVID-19)

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), characterised by high levels of inflammation and oxidative stress (OS). Oxidative stress induces oxidative damage to lipids, proteins, and DNA, causing tissue damage. Both inflammation and OS contribute to multi-organ failure in severe cases. Magnesium (Mg²⁺ ) regulates many processes, including antioxidant and anti-inflammatory responses, as well as the proper functioning of other micronutrients such as vitamin D. In addition, Mg²⁺ participates as a second signalling messenger in the activation of T cells. Therefore, Mg²⁺ deficiency can cause immunodeficiency, exaggerated acute inflammatory response, decreased antioxidant response, and OS. Supplementation with Mg²⁺ has an anti-inflammatory response by reducing the levels of nuclear factor kappa B (NF-κB), interleukin (IL) -6, and tumor necrosis factor alpha. Furthermore, Mg²⁺ supplementation improves mitochondrial function and increases the antioxidant glutathione (GSH) content, reducing OS. Therefore, Mg²⁺ supplementation is a potential way to reduce inflammation and OS, strengthening the immune system to manage COVID-19. This narrative review will address Mg²⁺ deficiency associated with a worse disease prognosis, Mg²⁺ supplementation as a potent antioxidant and anti-inflammatory therapy during and after COVID-19 disease, and suggest that randomised controlled trials are indicated.

Metabolic responses in the cortex and hippocampus induced by Il-15rα mutation

Metabolomics showed distinct metabolic phenotypes of the different brain regions related to the IL-15 system, enhancing our understanding of the IL-15 system and its interactions with neuropsychiatric disorders.