Semaglutide, a novel glucagon-like peptide-1 agonist, amends experimental autoimmune encephalomyelitis-induced multiple sclerosis in mice: Involvement of the PI3K/Akt/GSK-3β pathway

Tripterygium glycoside tablets and triptolide alleviate experimental autoimmune encephalomyelitis mice involving the PACAP/cAMP signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygiumwilfordii, a traditional Chinese herbal medicine, has been used for treating autoimmune diseases, including rheumatoid arthritis and systemic lupus erythematosus. Tripterygium glycoside tablets (TGT), derived from this herb, is widely used in clinical practice in China. However, the therapeutic effects of TGT on Multiple sclerosis (MS), particularly through its active component triptolide (TP), remain insufficiently understood.

AIM OF THE STUDY

This study aimed to investigate the therapeutic effects of TGT and TP on experimental autoimmune encephalomyelitis (EAE) and elucidate the underlying molecular mechanisms.

MATERIALS AND METHODS

TGT and TWPT were chemically characterized using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The therapeutic effect of TGT, TWPT, and TP was evaluated in the EAE model. Proteomics analysis and Western blot analysis were validated the signaling pathways.

RESULTS

TGT and TP significantly alleviated EAE symptoms in mice, including reduced weight loss and neurological deficits, whereas TWPT (TGT without triptolide) shows no significant therapeutic effect. Histological analysis revealed that TGT and TP reduced demyelination and inflammatory cell infiltration in the spinal cord. TGT and TP decreased systemic inflammatory cytokines (IL-17A, IFN-γ, TNF-α, and IL-6) and the mRNA expression of the transcription factors T-bet and ROR-γt in the spinal cord. Proteomic analysis indicated that TP significantly upregulated the expression of PACAP and activated the cAMP signaling pathway. Furthermore, TGT and TP modulate PKA, PI3K-AKT, NF-κB, and apoptosis-related signaling pathways, contributing to the reducing inflammation, apoptosis and demyelination in EAE mice.

CONCLUSION

TGT and TP exert anti-inflammatory and demyelination-improving effects to alleviate both clinical and pathological manifestations of EAE in mice via the PACAP/cAMP signaling axis, suggesting TGT as promising therapeutic strategies for MS.

Role of GLP‑1 receptor agonists in sepsis and their therapeutic potential in sepsis‑induced muscle atrophy (Review)

Sepsis‑induced myopathy (SIM) is a common complication in intensive care units, which is often associated with adverse outcomes, primarily manifested as skeletal muscle weakness and atrophy. Currently, the management of SIM focuses on prevention strategies, as effective therapeutic options remain elusive. Glucagon‑like peptide‑1 (GLP‑1) receptor agonists (GLP‑1RAs) have garnered attention as hypoglycemic and weight‑loss agents, with an increasing body of research focusing on the extrapancreatic effects of GLP‑1. In preclinical settings, GLP‑1RAs exert protective effects against sepsis‑related multiple organ dysfunction through anti‑inflammatory and antioxidant mechanisms. Based on the existing research, we hypothesized that GLP‑1RAs may serve potential protective roles in the repair and regeneration of skeletal muscle affected by sepsis. The present review aimed to explore the relationship between GLP‑1RAs and sepsis, as well as their impact on muscle atrophy‑related myopathy. Furthermore, the potential mechanisms and therapeutic benefits of GLP‑1RAs are discussed in the context of muscle atrophy induced by sepsis.

Blocking hippocampal voltage-gated potassium channel Kv1.3 by dalfampridine abrogates cognitive impairment in experimental autoimmune encephalomyelitis mouse model

Multiple sclerosis (MS) is devastating motor disorders accompanied by cognitive impairments. Dalfampridine (Dal), was approved for treating MS via blocking voltage-gated potassium channel (Kv). Kv1.3 is one of Dals' targets that showed insults to cognitive function in preclinical and clinical cases. Yet, there is no study that has assessed the potentiality of Dal on Kv1.3-induced cognitive impairment in MS. Thus, the aim of the present study is to reveal the procognitive influence of Dal in the MS animal model. Mice were randomly assigned into four groups. Saline was administered to group 1, conversely groups 2, 3, and 4 received 2 shots of rat spinal cord emulsified with complete Freund's adjuvant. Group 3 received Dal (10 μg/mouse; p. o), while group 4 received Wortmannin (0.1 μg/mouse; i. c.v), a selective phosphoinositide 3-kinases (PI3K) inhibitor, before Dal administration. After 14 days, Dal alleviated motor deficits in the open field arena and rotarod with cognitive restoration in the novel object recognition task. These were accompanied by the reversal of hippocampal neuronal loss and demyelination in corpus callosum. Additionally, Dal inhibited Kv1.3 that enhanced survival signaling, viz; PI3K/Akt. Such activation abates neuroinflammatory markers, glycogen synthase kinase-3 beta (GSK-3β) and nuclear factor-κB levels with subsequent enhancement of BDNF. All these amendments were reversed by Wortmannin pre-administration. In conclusion, this study declares that blockade of Kv1.3 and modulation of PI3K/Akt/GSK-3β/BDNF axis with Dal could be proposed as a promising neuroprotective and memory-enhancing treatment in MS.

Exploring glucagon-like peptide-1 receptor agonists as potential disease-modifying agents in autoimmune diseases

BACKGROUND

Glucagon-like peptide-1 receptor (GLP-1R) agonists are emerging with therapeutic agents for the treatment of two of the most prevalent metabolic disorders: diabetes and obesity. However, the causal relationship between GLP-1R agonists and autoimmune diseases is still unclear.

METHODS

The available cis-eQTLs for drug target genes (GLP-1Rs) were used as proxies for exposure to GLP-1R agonists. Obesity and type 2 diabetes mellitus (T2DM) were used as positive controls to ensure the reliability of the genetic instrument. Mendelian randomization (MR) was performed to reveal the causal association of genetic proxy GLP-1R agonists with 18 autoimmune diseases from the IEU OpenGwas database and FinnGen database. Finally, the results of the two databases were analyzed via meta-analysis.

RESULTS

A total of 22 significant cis-eQTL single-nucleotide polymorphisms were included as genetic instruments. Positive control analysis revealed that GLP-1R agonists were significantly associated with obesity (OR = 0.826, p = 0.021) and T2DM (OR = 0.886, p < 0.001), which is consistent with the meta-analysis. MR analysis revealed that increased expression of the GLP-1R gene has a significant protective effect on type 1 diabetes mellitus (T1DM), hypothyroidism, primary biliary cholangitis (PBC) and rheumatoid arthritis (RA). However, the MR analysis suggested that increased expression of GLP-1R agonists may increase the risk of Graves' disease (GD), ulcerative colitis (UC) and psoriasis. Our findings were consistent with those of the meta-analysis.

CONCLUSIONS

This study provides new insights into potential adjuvant treatments for autoimmune diseases from the perspective of genetic variation and provides evidence for the safety of GLP-1R agonists.

Neuroprotective effects of semaglutide and metformin against rotenone-induced neurobehavioral changes in male diabetic rats

Pre-existing diabetes raises the likelihood of Parkinson's disease (PD), according to epidemiological and animal research. Our study aimed to investigating the likely neuroprotective effect of metformin (Met) and/or semaglutide (Sem) in model of PD in male diabetic rats and the possible underlying mechanism. Type 2 diabetes (T2DM) was induced by giving high-fat diet (HFD) for 3 weeks followed by a single streptozotocin (STZ) injection (40 mg/kg, i.p., once dose) followed by injection of 9 doses of rotenone every 48 ± 2 h for induction of PD. Met and/or Sema were administered to DM+PD via gastric gavage once daily for 4 weeks. In comparison with the DM+PD group, Met and/or Sem significantly lowered blood glucose levels, HOMA-IR, HbA1C, cholesterol, triglycerides, and LDL with significantly increased insulin and HDL levels. In addition, there was enhanced brain antioxidant status with lower oxidative-inflammatory stress biomarkers associated with improved rat cognitive, locomotor, and olfactory functions. A significant downregulation of caspase 3 and GFAP with concomitant upregulation of NRF2 protein expressions were observed in treated groups. Overall, co-treatment with Met and Sem elicited more efficacy than that of the individual regimen. When combined, the results of this study have demonstrated for the first time that Met and Sem work in concert to create neuroprotection in PD model of male diabetic rats compared to when taken separately. The study's findings indicate that Met and/or Sem have a restorative effect on T2DM and PD-induced changes in neurobehavioral and biochemical/molecular indices ascribed to the improvement of endogenous antioxidant systems, decreased lipid peroxidation, suppression of oxidative/inflammatory stress, and-most importantly-regulation of Nrf2 and caspase 3.

Beyond weight loss: exploring the neurological ramifications of altered gut microbiota post-bariatric surgery

This review discusses findings related to neurological disorders, gut microbiota, and bariatric surgery, focusing on neurotransmitters, neuroendocrine, the pathophysiology of bacteria contributing to disorders, and possible therapeutic interventions. Research on neurotransmitters suggests that their levels are heavily influenced by gut microbiota, which may link them to neurological disorders such as Alzheimer's disease, Parkinson's disease, Multiple sclerosis, Depression, and Autism spectrum disorder. The pathophysiology of bacteria that reach and influence the central nervous system has been documented. Trends in microbiota are often observed in specific neurological disorders, with a prominence of pro-inflammatory bacteria and a reduction in anti-inflammatory types. Furthermore, bariatric surgery has been shown to alter microbiota profiles similar to those observed in neurological disorders. Therapeutic interventions, including fecal microbiota transplants and probiotics, have shown potential to alleviate neurological symptoms. We suggest a framework for future studies that integrates knowledge from diverse research areas, employs rigorous methodologies, and includes long-trial clinical control groups.

Semaglutide ameliorates metabolic disorders in offspring via regulation of oocyte ROS of pre-pregnancy obesity mice

Pre-pregnancy obesity (PPO) seriously threatens the health of both mother and offspring. Pre-pregnancy weight management is particularly important for the prevention of metabolic diseases in offspring. Semaglutide is one of the most effective glucagon-like peptide-1 agonizts for the management of obesity and metabolic diseases, but little is known about its effect on the long-term health of offspring. In this study we investigated the effects of semaglutide administered before pregnancy on the offspring health from PPO mice. PPO mice model was established by feeding with high-fat diet for 16 weeks, and then injected with semaglutide (30 nmol/kg-1·d-1, sc.) for 22 days before pregnancy. After the treatment, the mice were mated with normal males or underwent in vitro fertilization (IVF) for offspring reproduction. We showed that the semaglutide treatment not only improved the lipid and glucose metabolic disorders and fertility of PPO mice, but also significantly reversed the overweight, impaired energy balance, adipose inflammatory state, lipid and glucose metabolic disorders and insulin resistance of their IVF offspring. By conducting RNA-seq analysis, SOD activity and malondialdehyde assays in ovaries, as well as ROS staining in oocytes, we revealed that the semaglutide treatment reduced the elevated oxidative stress in ovaries and high ROS levels in oocytes from PPO mice, possibly through activating the PI3K/AKT pathway and improving the state of SOD. Interestingly, incubation of oocytes from semaglutide-treated dams with H2O2 (100 μM) in vitro during IVF blocked the protective effects of semaglultide against the metabolic disorders in the offspring. In conclusion, semaglutide treatment before pregnancy effectively alleviates obesity-related metabolic disorders in offspring. The regulation of ROS in oocytes plays a crucial role in the protective effects of semaglutide.

Investigating the Interplay Between the Nrf2/Keap1/HO-1/SIRT-1 Pathway and the p75NTR/PI3K/Akt/MAPK Cascade in Neurological Disorders: Mechanistic Insights and Therapeutic Innovations

Neurological illnesses are debilitating diseases that affect brain function and balance. Due to their complicated aetiologies and progressive nature, neurodegenerative and neuropsychiatric illnesses are difficult to treat. These incurable conditions damage brain functions like mobility, cognition, and emotional regulation, but medication, gene therapy, and physical therapy can manage symptoms. Disruptions in cellular signalling pathways, especially those involving oxidative stress response, memory processing, and neurotransmitter modulation, contribute to these illnesses. This review stresses the interplay between key signalling pathways involved in neurological diseases, such as the Nrf2/Keap1/HO-1/SIRT-1 axis and the p75NTR/PI3K/Akt/MAPK cascade. To protect neurons from oxidative damage and death, the Nrf2 transcription factor promotes antioxidant enzyme production. The Keap1 protein releases Nrf2 during oxidative stress for nuclear translocation and gene activation. The review also discusses how neurotrophin signalling through the p75 neurotrophin receptor (p75NTR) determines cell destiny, whether pro-survival or apoptotic. The article highlights emerging treatment approaches targeting these signalling pathways by mapping these connections. Continued research into these molecular pathways may lead to new neurological disease treatments that restore cellular function and neuronal survival. In addition to enhanced delivery technologies, specific modulators and combination therapies should be developed to fine-tune signalling responses. Understanding these crosstalk dynamics is crucial to strengthening neurological illness treatment options and quality of life.

Acupoint catgut embedding alleviates experimental autoimmune encephalomyelitis by modulating neuroinflammation and potentially inhibiting glia activation through JNK and ERK pathways

Background

Acupoint catgut embedding (ACE) is a traditional Chinese medicine technique commonly used for managing various disorders, including chronic inflammatory pain and allergic asthma. Despite its growing use, the neuroimmunological mechanisms underlying ACE treatment effects remain unclear.

Methods

This study investigated the roles and potential mechanisms of the effects of ACE in treating experimental autoimmune encephalomyelitis (EAE), a frequently used animal model of autoimmune neuroinflammation. The effects of ACE treatment were evaluated by monitoring body weight and EAE severity scores. Behavioral tests, histopathological analysis, ELISA, and flow cytometry were conducted to assess the therapeutic efficacy of ACE. RNA sequencing was performed to uncover ACE-associated transcriptional signatures in the spinal cords of EAE mice.

Results

The results were validated through western blotting, qRT-PCR, and immunofluorescence (IF) staining. In ACE-treated mice, EAE disease severity was significantly ameliorated, along with improvements in anxiety-like behaviors and reduced inflammation and demyelination. The ACE treatment restored immune imbalance in the EAE mice by decreasing Th17 and Th1 cells, while increasing Treg cells in peripheral immune organs and reducing serum inflammatory cytokine levels. RNA sequencing revealed significant suppression of the genes and pathways associated with reactive microglial and astrocytic activation, corroborated by IF studies. Additionally, ACE treatment could suppress the ERK and JNK signaling pathways at both RNA and protein levels.

Conclusion

These findings confirm the protective role of ACE in mitigating EAE symptoms by modulating microglial and astrocytic activity and regulating inflammatory cytokines.

The SIRT-1/Nrf2/HO-1 axis: Guardians of neuronal health in neurological disorders

SIRT1 (Sirtuin 1) is a NAD+-dependent deacetylase that functions through nucleoplasmic transfer and is present in nearly all mammalian tissues. SIRT1 is believed to deacetylate its protein substrates, resulting in neuroprotective actions, including reduced oxidative stress and inflammation, increased autophagy, increased nerve growth factors, and preserved neuronal integrity in aging or neurological disease. Nrf2 is a transcription factor that regulates the genes responsible for oxidative stress response and substance detoxification. The activation of Nrf2 guards cells against oxidative damage, inflammation, and carcinogenic stimuli. Several neurological abnormalities and inflammatory disorders have been associated with variations in Nrf2 activation caused by either pharmacological or genetic factors. Recent evidence indicates that Nrf2 is at the center of a complex cellular regulatory network, establishing it as a transcription factor with genuine pleiotropy. HO-1 is most likely a component of a defense mechanism in cells under stress, as it provides negative feedback for cell activation and mediator synthesis. This mediator is upregulated by Nrf2, nitric oxide (NO), and other factors in various inflammatory states. HO-1 or its metabolites, such as CO, may mitigate inflammation by modulating signal transduction pathways. Neurological diseases may be effectively treated by modulating the activity of HO-1. Multiple studies have demonstrated that SIRT1 and Nrf2 share an important connection. SIRT1 enhances Nrf2, activates HO-1, protects against oxidative injury, and decreases neuronal death. This has been associated with numerous neurodegenerative and neuropsychiatric disorders. Therefore, activating the SIRT1/Nrf2/HO-1 pathway may help treat various neurological disorders. This review focuses on the current understanding of the SIRT1 and Nrf2/HO-1 neuroprotective processes and the potential therapeutic applications of their target activators in neurodegenerative and neuropsychiatric disorders.

Glucagon-like peptide-1 agonist safety and efficacy in a multiple sclerosis cohort

BACKGROUND

While glucagon-like peptide-1 agonist medications (GLP-1s) are on the rise, their safety and efficacy have not been studied in people with MS (PwMS).

OBJECTIVE

To investigate any adverse effects of GLP-1 medications in the MS population as well as their effectiveness for weight loss and vitamin D augmentation.

METHODS

We retrospectively identified PwMS who utilized a GLP-1 medication from 2006 to 2024. Wilcoxon signed rank tests for paired samples were used to compare pre- and post-GLP-1 body mass index (BMI), expanded disability status scale (EDSS), timed 25-foot walk (25FTW), and mean vitamin D values. Additional safety outcomes assessed during GLP-1 treatment were deaths, hospitalizations, clinician-confirmed relapses, and new MRI activity.

RESULTS

Following GLP-1 initiation, PwMS had a decrease in BMI (mean % BMI loss 3.7, p = 0.001) and an increase in vitamin D values (mean increase of 8.1 ng/mL, p = 0.0002), while no change in EDSS or T25FW was seen. There were no hospitalizations or deaths after GLP-1 initiation.

CONCLUSION

GLP-1 medications are safe and effective in PwMS and can help augment vitamin D levels.

Semaglutide ameliorated autism-like behaviors and DNA repair efficiency in male BTBR mice by recovering DNA repair gene expression

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that is marked by impaired social interactions, and increased repetitive behaviors. There is evidence of genetic changes in ASD, and several of these altered genes are linked to the process of DNA repair. Therefore, individuals with ASD must have improved DNA repair efficiency to mitigate risks associated with ASD. Despite numerous milestones in ASD research, the disease remains incurable, with a high occurrence rate and substantial financial burdens. This motivates scientists to search for new drugs to manage the disease. Disruption of glucagon-like peptide-1 (GLP-1) signaling, a regulator in neuronal development and maintains homeostasis, has been associated with the pathogenesis and progression of several neurological disorders, such as ASD. Our study aimed to assess the impact of semaglutide, a new GLP-1 analog antidiabetic medication, on behavioral phenotypes and DNA repair efficiency in the BTBR autistic mouse model. Furthermore, we elucidated the underlying mechanism(s) responsible for the ameliorative effects of semaglutide against behavioral problems and DNA repair deficiency in BTBR mice. The current results demonstrate that repeated treatment with semaglutide efficiently decreased autism-like behaviors in BTBR mice without affecting motor performance. Semaglutide also mitigated spontaneous DNA damage and enhanced DNA repair efficiency in the BTBR mice as determined by comet assay. Moreover, administering semaglutide recovered oxidant-antioxidant balance in BTBR mice. Semaglutide restored the disrupted DNA damage/repair pathways in the BTBR mice by reducing Gadd45a expression and increasing Ogg1 and Xrcc1 expression at both the mRNA and protein levels. This suggests that semaglutide holds great potential as a novel therapeutic candidate for treating ASD traits.

Exploring the antioxidant properties of semaglutide: A comprehensive review

Patients with diabetes commonly experience an aberrant production of free radicals and weakened antioxidative defenses, making them highly susceptible to oxidative stress development. This, in turn, can induce and promote diabetic complications. Therefore, utilizing antidiabetic agents with antioxidative properties can offer dual benefits by addressing hyperglycemia and reducing oxidative damage. Semaglutide, a recently approved oral form of glucagon-like peptide-1 (GLP-1) analogues, has shown potent antidiabetic effects. Additionally, recent studies have suggested that it possesses antioxidative properties. However, the exact effects and the molecular pathways involved are not well understood. In this review, we present the latest findings on the antioxidative impacts of semaglutide and draw conclusions about the mechanisms involved.

Semaglutide decelerates the growth and progression of breast cancer by enhancing the acquired antitumor immunity

Semaglutide, a glucagon-like peptide 1 receptor agonist, is an antidiabetic that has recently shown promising immunomodulatory and antitumor effects. Breast cancer is the most common type of cancer affecting women worldwide. The aim of this study was to analyze the effects of semaglutide on the antitumor immunity in a 4T1 mouse breast cancer model. After induction of breast cancer, BALB/C mice were treated intraperitoneally with semaglutide. Semaglutide administration decelerated tumor appearance, growth and progression. The antidiabetic drug showed neither a direct cytotoxic effect in vitro, nor an angiogenic effect. Furthermore, depletion of NK cells had no affect on tumor growth in semaglutide treated mice suggesting a non-NK cell-dependent mechanism. However, semaglutide increased the accumulation and maturation of CD11c+ dendritic cell, while decreasing the percentage of FoxP3+ regulatory T cells in the spleen and primary tumor. In addition, semaglutide increased tumor infiltration and promoted the antitumor phenotype of T cells, in vivo. Furthermore, semaglutide enhanced the cytotoxic capacity of CD8+ T cells, in vitro. These results suggest that semaglutide enhances the acquired antitumor immune response and has potential for the future treatment of malignancies.

Vortioxetine ameliorates experimental autoimmune encephalomyelitis model of multiple sclerosis in mice via activation of PI3K/Akt/CREB/BDNF cascade and modulation of serotonergic pathway signaling

Multiple sclerosis (MS) is a chronic condition characterized by immune cell infiltration and cytokine overproduction that led to myelin sheath inflammatory assaults, thus causing axonal destruction. The former consequently provokes motor impairment and psychological disorders. Markedly, depression is one of the most prevalent lifelong comorbidities that negatively impacts the quality of life in MS patients. Vortioxetine (VTX), a multi-modal molecule prescribed to manage depression and anxiety disorder, additionally, it displays a promising neuroprotective properties against neurodegenerative diseases such as Alzheimer's and Parkinson's. To this end, the present study investigated the potential therapeutic efficacy of VTX against experimental autoimmune encephalomyelitis (EAE) model of MS in mice. Notably, treatment with VTX significantly ameliorated EAE-induced motor disability, as evident by enhanced performance in open field, rotarod and grip strength tests, alongside a reduction in immobility time during the forced swimming test, indicating a mitigation of the depressive-like behavior; outcomes that were corroborated with histological examinations and biochemical analyses. Mechanistically, VTX enhanced serotonin levels by inhibiting both serotonin transporter (SERT) and indoleamine 2,3-dioxygenase (IDO) enzyme, thereby promoting the activation of serotonin 1A (5-HT1A) receptor. The latter triggered the stimulation of phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) cascade that entailed activation/phosphorylation of cAMP response element-binding protein (CREB). This activation increased brain derived neurotrophic factor (BDNF) and myelin basic protein (MBP) contents that mitigated demyelination in the corpus callosum. Furthermore, VTX suppressed phospho serine 536 nuclear factor kappa B (pS536 NF-κB p65) activity and reduced tumor necrosis factor-alpha (TNF-α) production. The results underscore VTX's beneficial effects on disease severity in EAE model of MS in mice by amending both inflammatory and neurodegenerative components of MS progression.

The Role of Glucagon-Like Peptide-1 Agonists in the Treatment of Multiple Sclerosis: A Narrative Review

Multiple sclerosis (MS) is a chronic, progressive autoimmune disease modulated by autoantibodies that inflame and destroy the myelin sheath encasing neuronal axons, impairing proper axonal conduction and function. Glucagon-like peptide-1 (GLP-1) receptor agonists have been demonstrated to exert anti-inflammatory and neuroprotective effects, making these drugs particularly exciting prospects in the treatment of MS. While the exact mechanism remains unclear, GLP-1 receptor agonists may modulate inflammatory responses by targeting GLP-1 receptors present on immune cells such as macrophages, monocytes, and lymphocytes. In animal models, GLP-1 agonists have been shown to significantly delay the onset and severity of experimental autoimmune encephalopathy symptoms, as well as to increase nerve myelination and brain weight. In further experiments using animal models of nerve crush injury, specimens given GLP-1 agonists reported a significant increase in the rate and density of nerve regeneration compared to controls. Thus, GLP-1 agonists show promise as both prophylactic and symptomatic treatment for MS and may provide further utility in the treatment of other autoimmune, inflammatory, and neurodegenerative conditions.

Glucagon-like peptide 1 receptor activation: anti-inflammatory effects in the brain

The glucagon-like peptide 1 is a pleiotropic hormone that has potent insulinotropic effects and is key in treating metabolic diseases such as diabetes and obesity. Glucagon-like peptide 1 exerts its effects by activating a membrane receptor identified in many tissues, including different brain regions. Glucagon-like peptide 1 activates several signaling pathways related to neuroprotection, like the support of cell growth/survival, enhancement promotion of synapse formation, autophagy, and inhibition of the secretion of proinflammatory cytokines, microglial activation, and apoptosis during neural morphogenesis. The glial cells, including astrocytes and microglia, maintain metabolic homeostasis and defense against pathogens in the central nervous system. After brain insult, microglia are the first cells to respond, followed by reactive astrocytosis. These activated cells produce proinflammatory mediators like cytokines or chemokines to react to the insult. Furthermore, under these circumstances, microglia can become chronically inflammatory by losing their homeostatic molecular signature and, consequently, their functions during many diseases. Several processes promote the development of neurological disorders and influence their pathological evolution: like the formation of protein aggregates, the accumulation of abnormally modified cellular constituents, the formation and release by injured neurons or synapses of molecules that can dampen neural function, and, of critical importance, the dysregulation of inflammatory control mechanisms. The glucagon-like peptide 1 receptor agonist emerges as a critical tool in treating brain-related inflammatory pathologies, restoring brain cell homeostasis under inflammatory conditions, modulating microglia activity, and decreasing the inflammatory response. This review summarizes recent advances linked to the anti-inflammatory properties of glucagon-like peptide 1 receptor activation in the brain related to multiple sclerosis, Alzheimer's disease, Parkinson's disease, vascular dementia, or chronic migraine.

Dihydroartemisinin ameliorates experimental autoimmune myasthenia gravis by regulating CD4+ T cells and modulating gut microbiota

BACKGROUND

Dihydroartemisinin (DHA), a derivative and active metabolite of artemisinin, possesses various immunomodulatory properties. However, its role in myasthenia gravis (MG) has not been clearly explored. Here, we investigated the role of DHA in experimental autoimmune myasthenia gravis (EAMG) and its potential mechanisms.

METHODS

The AChR97-116 peptide-induced EAMG model was established in Lewis rats and treated with DHA. Flow cytometry was used to assess the release of Th cell subsets and Treg cells, and 16S rRNA gene amplicon sequence analysis was applied to explore the relationship between the changes in the intestinal flora after DHA treatment. In addition, network pharmacology and molecular docking were utilized to explore the potential mechanism of DHA against EAMG, which was further validated in the rat model by immunohistochemical and RT-qPCR for further validation.

RESULTS

In this study, we demonstrate that oral administration of DHA ameliorated clinical symptoms in rat models of EAMG, decreased the expression level of Th1 and Th17 cells, and increased the expression level of Treg cells. In addition, 16S rRNA gene amplicon sequence analysis showed that DHA restored gut microbiota dysbiosis in EAMG rats by decreasing Ruminococcus abundance and increasing the abundance of Clostridium, Bifidobacterium, and Allobaculum. Using network pharmacology, 103 potential targets of DHA related to MG were identified, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that PI3K-AKT signaling pathway was related to the treatment of DHA on EAMG. Meanwhile, molecular docking verified that DHA has good binding affinity to AKT1, CASP3, EGFR, and IGF1. Immunohistochemical staining showed that DHA treatment significantly inhibited the phosphorylated expression of AKT and PI3K in the spleen tissues of EAMG rats. In EAMG rats, RT-qPCR results also showed that DHA reduced the mRNA expression levels of PI3K and AKT1.

CONCLUSIONS

DHA ameliorated EAMG by inhibiting the PI3K-AKT signaling pathway, regulating CD4+ T cells and modulating gut microbiota, providing a novel therapeutic approach for the treatment of MG.

Unlocking the Potential: Semaglutide's Impact on Alzheimer's and Parkinson's Disease in Animal Models

Semaglutide (SEM), a glucagon-like peptide-1 receptor agonist, has garnered increasing interest for its potential therapeutic effects in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). This review provides a comprehensive description of SEM's mechanism of action and its effects in preclinical studies of these debilitating conditions. In animal models of AD, SEM has proved beneficial effects on multiple pathological hallmarks of the disease. SEM administration has been associated with reductions in amyloid-beta plaque deposition and mitigation of neuroinflammation. Moreover, SEM treatment has been shown to ameliorate behavioral deficits related to anxiety and social interaction. SEM-treated animals exhibit improvements in spatial learning and memory retention tasks, as evidenced by enhanced performance in maze navigation tests and novel object recognition assays. Similarly, in animal models of PD, SEM has demonstrated promising neuroprotective effects through various mechanisms. These include modulation of neuroinflammation, enhancement of mitochondrial function, and promotion of neurogenesis. Additionally, SEM has been shown to improve motor function and ameliorate dopaminergic neuronal loss, offering the potential for disease-modifying treatment strategies. Overall, the accumulating evidence from preclinical studies suggests that SEM holds promise as a novel therapeutic approach for AD and PD. Further research is warranted to elucidate the underlying mechanisms of SEM's neuroprotective effects and to translate these findings into clinical applications for the treatment of these devastating neurodegenerative disorders.

A Systematic Review of Semaglutide's Influence on Cognitive Function in Preclinical Animal Models and Cell-Line Studies

Since we aim to test new options to find medication for cognitive disorders, we have begun to assess the effect of semaglutide and to conduct a review gathering studies that have attempted this purpose. This systematic review focuses on the cognitive effects of semaglutide, a glucagon-like peptide 1 receptor agonist (GLP-1 RA), in the context of neurological and cognitive impairment. Semaglutide, a synthetic GLP-1 analog, showcased neuroprotective effects beyond metabolic regulation. It mitigated apoptosis and improved cognitive dysfunction in cerebrovascular disease, suggesting broader implications for neurological well-being. Also, studies highlighted GLP-1 RAs' positive impact on olfactory function in obese individuals with type 2 diabetes, on neurodegenerative disorders, multiple sclerosis, and endotoxemia. In order to analyze current studies that assess the impact of semaglutide on cognitive function, a literature search was conducted up to February 2024 on two online databases, MEDLINE (via PubMed) and Web of Science Core Collection, as well as various websites. Fifteen studies on mice populations and two studies on cell lines were included, analyzed, and assessed with bias-specific tools. The neuroprotective and anti-apoptotic properties of GLP-1 and its analogs were emphasized, with animal models and cell line studies demonstrating enhanced cognitive function. While promising, limitations include fewer studies, highlighting the need for extensive research, particularly in the human population. Even though this medication seems promising, there are significant limitations, one of which is the lack of studies on human subjects. Therefore, this review aims to gather current evidence.

Neuroprotective effect of curcumin against experimental autoimmune encephalomyelitis-induced cognitive and physical impairments in mice: an insight into the role of the AMPK/SIRT1 pathway

Multiple sclerosis (MS) is an incurable chronic neurodegenerative disease where autoimmunity, oxidative stress, and neuroinflammation collaboration predispose myelin sheath destruction. Interestingly, curcumin, a natural polyphenol, showed a neuroprotective effect in numerous neurodegenerative diseases, including MS. Nevertheless, the influence of curcumin against MS-induced cognitive impairment is still vague. Hence, we induced experimental autoimmune encephalomyelitis (EAE) in mice using spinal cord homogenate (SCH) and complete Freund's adjuvant, which eventually mimic MS. This study aimed not only to evaluate curcumin efficacy against EAE-induced cognitive and motor dysfunction, but also to explore a novel mechanism of action, by which curcumin exerts its beneficial effects in MS. Curcumin (200 mg/kg/day) efficacy was evaluated by behavioral tests, histopathological examination, and biochemical tests. Concisely, curcumin amended EAE-induced cognitive and motor impairments, as demonstrated by the behavioral tests and histopathological examination of the hippocampus. Interestingly, curcumin activated the adenosine monophosphate (AMP)-activated protein kinase/silent mating type information regulation 2 homolog 1 (AMPK/SIRT1) axis, which triggered cyclic AMP response element-binding protein/brain-derived neurotrophic factor/myelin basic protein (CREB/BDNF/MBP) pathway, hindering demyelination of the corpus callosum. Furthermore, AMPK/SIRT1 activation augmented nuclear factor erythroid 2-related factor 2 (Nrf2), a powerful antioxidant, amending EAE-induced oxidative stress. Additionally, curcumin abolished EAE-induced neuroinflammation by inhibiting Janus kinase 2 /signal transducers and activators of transcription 3 (JAK2/STAT3) axis, by various pathways, including AMPK/SIRT1 activation. JAK2/STAT3 inhibition halts inflammatory cytokines synthesis. In conclusion, curcumin's neuroprotective effect in EAE is controlled, at least in part, by AMPK/SIRT1 activation, which ultimately minimizes EAE-induced neuronal demyelination, oxidative stress, and neuroinflammation.

Comparative effects of incretin-based therapy on doxorubicin-induced nephrotoxicity in rats: the role of SIRT1/Nrf2/NF-κB/TNF-α signaling pathways

Introduction: Nephrotoxicity represents a major complication of using doxorubicin (DOX) in the management of several types of cancers. Increased oxidative stress and the activation of inflammatory mediators play outstanding roles in the development of DOX-induced kidney damage. This study aimed to investigate whether the two pathways of incretin-based therapy, glucagon-like peptide-1 receptor agonist (presented as semaglutide, SEM) and dipeptidyl peptidase-4 inhibitor (presented as alogliptin, ALO), differentially protect against DOX-induced nephrotoxicity in rats and to clarify the underlying molecular mechanisms. Methods: Adult male rats were divided into six groups: control (received the vehicle), DOX (20 mg/kg, single I.P. on day 8), DOX + ALO (20 mg/kg/day, P.O. for 10 days), DOX + SEM (12 μg/kg/day, S.C. for 10 days), ALO-alone, and SEM-alone groups. At the end of the study, the animals were sacrificed and their kidney functions, oxidative stress, and inflammatory markers were assessed. Kidney sections were also subjected to histopathological examinations. Results: The co-treatment with either ALO or SEM manifested an improvement in the kidney functions, as evidenced by lower serum concentrations of creatinine, urea, and cystatin C compared to the DOX group. Lower levels of MDA, higher levels of GSH, and increased SOD activity were observed in either ALO- or SEM-treated groups than those observed in the DOX group. DOX administration resulted in decreased renal expressions of sirtuin 1 (SIRT1) and Nrf2 with increased NF-κB and TNF-α expressions, and these effects were ameliorated by treatment with either ALO or SEM. Discussion: Co-treatment with either ALO or SEM showed a renoprotective effect that was mediated by their antioxidant and anti-inflammatory effects via the SIRT1/Nrf2/NF-κB/TNF-α pathway. The fact that both pathways of the incretin-based therapy demonstrate an equally positive effect in alleviating DOX-induced renal damage is equally noteworthy.

Nicorandil and carvedilol mitigates motor deficits in experimental autoimmune encephalomyelitis-induced multiple sclerosis: Role of TLR4/TRAF6/MAPK/NF-κB signalling cascade

Multiple sclerosis (MS) is an inflammatory demyelinating neurodegenerative disease that negatively affects neurotransmission. It can be pathologically mimicked by experimental autoimmune encephalomyelitis (EAE) animal model. ATP-sensitive potassium channels (KATP) plays a crucial role in the control of neuronal damage, however their role in MS are still obscure. Additionally, Carvedilol showed a promising neuroprotective activity against several neurological disorders. Therefore, the present study aimed to investigate the potential neuroprotective effect of KATP channel opener (nicorandil) as well as α and β adrenoceptor antagonist (Carvedilol) against EAE induced neurodegeneration in mice. Mice was treated with nicorandil (6 mg/kg/day; p.o.) and carvedilol (10 mg/kg/day; p.o.) for 14 days. Nicorandil and carvedilol showed improvement in clinical scoring, behaviour and motor coordination as established by histopathological investigation and immunohistochemical detection of MBP. Furthermore, both treatments downregulated the protein expression of TLR4/ MYD88/TRAF6 signalling cascade with downstream inhibition of (pT183/Y185)-JNK/p38 (pT180/Y182)-MAPK axis leading to reduction of neuroinflammatory status, as witnessed by reduction of NF-κB, TNF-α, IL-1β and IL-6 contents. Moreover, nicorandil and carvedilol attenuated oxidative damage by increasing Nrf2 content and SOD activity together with reduction of MDA content. In addition, an immunomodulating effect via inhibiting the gene expression of CD4, TGF-β, and IL-17 as well as TGF-β, IL-17, and IL-23 contents along with anti-apoptotic effect by decreasing Bax protein expression and Caspase-3 content and increasing Bcl-2 protein expression was observed with nicorandil and carvedilol treatments. In conclusion, nicorandil and carvedilol exerted a neuroprotective activity against EAE induced neuronal loss via inhibition of TLR4/MYD88/TRAF6/JNK/p38-MAPK axis besides antioxidant and anti-apoptotic effects.

Inosine attenuates rotenone-induced Parkinson's disease in rats by alleviating the imbalance between autophagy and apoptosis

Growing evidence points to impaired autophagy as one of the major factors implicated in the pathophysiology of Parkinson's disease (PD). Autophagy is a downstream target of adenosine monophosphate-activated protein kinase (AMPK). Inosine has already demonstrated a neuroprotective effect against neuronal loss in neurodegenerative diseases, mainly due its anti-inflammatory and antioxidant properties. We, herein, aimed at investigating the neuroprotective effects of inosine against rotenone-induced PD in rats and to focus on the activation of AMPK-mediated autophagy. Inosine successfully increased p-AMPK/AMPK ratio in PD rats and improved their motor performance and muscular co-ordination (assessed by rotarod, open field, and grip strength tests, as well as by manual gait analysis). Furthermore, inosine was able to mitigate the rotenone-induced histopathological alterations and to restore the tyrosine hydroxylase immunoreactivity in PD rats' substantia nigra. Inosine-induced AMPK activation resulted in an autophagy enhancement, as demonstrated by the increased striatal Unc-S1-like kinase1 and beclin-1 expression, and also by the increment light chain 3II to light chain 3I ratio, along with the decline in striatal mammalian target of rapamycin and p62 protein expressions. The inosine-induced stimulation of AMPK also attenuated neuronal apoptosis and promoted antioxidant activity. Unsurprisingly, these neuroprotective effects were antagonized by a preadministration of dorsomorphin (an AMPK inhibitor). In conclusion, inosine exerted neuroprotective effects against the rotenone-induced neuronal loss via an AMPK activation and through the restoration of the imbalance between autophagy and apoptosis. These findings support potential application of inosine in PD treatment.