Neuroprotective Effects Research Articles

The neuroprotective effects of progesterone against peripheral neuropathy: a systematic review of non-clinical studies

The neuroprotective effects of progesterone against peripheral neuropathy: a systematic review of non-clinical studies

Diacerein ameliorates thioacetamide-induced hepatic encephalopathy in rats via modulation of TLR4/AQP4/MMP-9 axis

AbstractAstrocyte swelling, blood brain barrier (BBB) dissipation and the subsequent brain edema are serious consequences of persistent hyperammonemia in hepatic encephalopathy (HE) in which if inadequately controlled it will lead to brain death. The current study highlights the potential neuroprotective effect of diacerein against thioacetamide (TAA)-induced HE in acute liver failure rat model. HE was induced in male Sprague–Dawley rats via I.P. injection of TAA (200 mg/kg) for three alternative times/week at 3rd week of the experiment. Diacerein (50 mg/kg) was gavaged for 14 days prior to induction of HE and for further 7 days together with TAA injection for an overall period of 21 days. Diacerein attenuated TAA-induced HE in acute liver failure rat model; as proofed by significant lowering of serum and brain ammonia concentrations, serum AST and ALT activities and significant attenuation of both brain and hepatic MDA contents and IL-1β with marked increases in GSH contents (P < 0.0001). The neuroprotective effect of diacerein was demonstrated by marked improvement of motor and cognitive deficits, brain histopathological changes; hallmarks of HE. As shown by immunohistochemical results, diacerein markedly downregulated brain TLR4 expression which in turn significantly increased the GFAP expression, and significantly decreased AQP4 expression; the astrocytes swelling biomarkers (P < 0.0001). Moreover, diacerein preserved BBB integrity via downregulation of MMP-9 mediated digestion of tight junction proteins such as occludin (P < 0.0001). Collectively, diacerein ameliorated cerebral edema and maintained BBB integrity via modulation of TLR4/AQP4/MMP-9 axis thus may decrease the progression of HE induced in acute liver failure.

Understanding the Best Nutritional Management for Creutzfeldt–Jakob Disease Patients: A Comparison Between East Asian and Western Experiences

(1) Background: Creutzfeldt–Jakob disease (CJD) is a rare and fatal neurodegenerative disorder caused by the accumulation of an altered prion protein, which usually leads to death within one year after clinical onset. CJD patients usually present with rapid cognitive impairment associated with declines in cerebellar, motor, visual, behavioral, and swallowing functions. Moreover, CJD patients lose their ability to eat and take medications orally very early on in treatment; nevertheless, there are no specific nutritional guidelines for this disease shared worldwide. (2) Methods: This review aims to describe the nutritional outcomes of CJD patients in Western countries to compare them with those described in East Asian countries and then aims to explore the most recent trends in the nutritional management of CJD patients, including some dietary compounds that present neuroprotective effects. (3) Results: In Japan’s, Taiwan’s, and China’s healthcare systems, CJD patients receive intensive life-sustaining treatment that prolongs their survival (i.e., artificial feeding); conversely, in Western countries, intensive life-sustaining treatments like tube feeding are not commonly provided to CJD patients. (4) Conclusions: It is difficult to pinpoint the reasons for these discrepancies around CJD palliative care supply, but it is clear that specific nutritional guidelines may directly improve the nutritional management of CJD patients and thus allow their families and caregivers to ensure the best end-of-life care for these patients.

Central responses to peripheral inflammation may include decreased expression of key apoptotic protease caspase-3 in brainstem

Microglia activation by proinflammatory stimuli, including lipopolysaccharide (LPS), is considered among the risk factors for neurodegeneration, but the LPS treatment may also have a neuroprotective effect, which leads to further analysis of the relationship between microglial activation and regulators of cell death. In the present work, a comparative study was carried out on proteins expression of marker for activated microglia Iba-1 and the apoptotic executor protease caspase-3 in the brainstem and prefrontal cortex of rats injected intraperitoneally with endotoxin at different doses and schedules. One day after LPS at a dose of 0.5 mg/kg, single, the Iba-1 and caspase-3 expression in both structures did not differ from control values. Endotoxin administration fourfold at the same dose over 7 days (once every 2 days) led one day after the last injection to a significant increase in the Iba-1 level in the brainstem, which was accompanied by a significant decrease in the expression of caspase-3. The same effects in this structure were observed 7 days after a single injection of LPS at a higher dose of 5 mg/kg. In a 7-day experiment, in contrast to the brainstem, no changes in caspase-3 expression were found in the frontal cortex, and an increase in Iba-1 expression was observed only after a single injection of LPS at a high dose. The detected decrease of caspase-3 level in the brain stem under neuroinflammatory conditions may reflect the development of neuroprotective processes, especially important for the structure responsible for such key body functions as respiration, blood pressure and heartbeat.

Neuroprotective Role of Zingerone: Investigating the Effective Doses of Zingerone in Lead Acetate-Induced Brain Dysfunctions in Rats

This experiment was designed to determine the effective dose of zingerone against the sublethal dose of lead acetate that induced brain dysfunctions in rats through using different successive doses of zingerone on some parameters related to oxidative stress for 28 days. Thirty-six adult male rats were randomly selected and divided equally into six experimental groups and treated for 28 days as follows: Control group: administered (orally) sterile distilled water. G1 group: administered (orally) (1/280 from LD50) of lead acetate and treated with 25mg/kg for 4 weeks, the rats were then dissected. G2 group: administered (orally) (1/280 from LD50) of lead acetate and treated with 50mg/kg for 4 weeks, the rats were then dissected. G3 group: administered (orally) (1/280 from LD50) of lead acetate and treated with 100mg/kg for 4 weeks, the rats were then dissected. G4 group: administered (orally) (1/280 from LD50) of lead acetate and treated with 150mg/kg for 4 weeks, the rats were then dissected. G5 group: administered (orally) (1/280 from LD50) of lead acetate and treated with 200mg/kg for 4 weeks, the rats were then dissected. Blood samples were collected, by heart punched under anesthesia, at the end of the experiment for measuring the serum malondialdehyde, neuroglobulin, and dopamine concentrations. The result showed a significant (P<0.05) positive correlation between successive doses of zingerone and dopamine and neuroglobulin concentrations, while a significant (P<0.05) negative correlation between successive doses of zingerone and the concentration of malondialdehyde in all animals that are treated with lead acetate compared to the control group. Concluded from this research show that the zingerone has potent antioxidants and neuroprotective effects at the dose 125 mg/kg BW may result in a significant improvement of the neurotransmitter levels and decrease in the production of oxidative stress to the brain tissue.

Morin Ameliorates Lipopolysaccharides-Induced Sepsis-Associated Encephalopathy and Cognitive Impairment in Albino Mice.

Sepsis-associated encephalopathy is a common neurological complication of sepsis that is characterized by neuroinflammation, oxidative stress and apoptosis, which results in cognitive impairments in septic survivors. Despite numerous treatment options for this condition, none of them are definite. Therefore, this study aimed to investigate the impact of morin, a flavone known for its neuroprotective and anti-inflammatory effects, against lipopolysaccharides-induced sepsis-associated encephalopathy in albino mice for 7 days. Mice were divided into 4 groups: Negative control, morin, septic, and septic morin-treated mice. Sepsis was induced by a single injection of lipopolysaccharides (5mg/kg, intraperitoneally), morin (50mg/kg b. wt.) was given orally, starting from 5h after sepsis induction, then daily for 4 other days. Morin ameliorated septic structural and functional alternations as manifested by improving the survival rate, the behavioral functions, in addition to preserving and protecting the brain tissue. This was accompanied with the augmentation of the total antioxidant capacity, as well as the suppression of tissue levels of the lipid peroxidation marker malondialdehyde, apoptosis (cleaved-caspase-3), glial fibrillary acidic protein, and the proinflammatory cytokine tumor necrosis factor. In conclusion, morin has a promising ameliorative effect to counteract the sepsis-associated encephalopathy via its anti-inflammatory and antioxidant effects and to prevent the associated cognitive impairments.

Phytochemicals from Passiflora coriacea Juss. Have Anti-Inflammatory and Neuroprotective Effects in Mouse Models

Background: Neuroinflammatory diseases trigger an inflammatory response and a state of oxidative stress. Passiflora coriacea Juss. has been used to treat conditions related to inflammatory processes in the central nervous system; however, to date, there has been no study on the anti-inflammatory and neuroprotective effects of this species. Methods: The anti-inflammatory effect of P. coriacea was evaluated in a TPA-induced auricular edema model, and the percentage of edema inhibition (Ei) was recorded. The Morris water maze was used to assess the neuroprotective effect, measuring the latency time (LT), and lipopolysaccharide was administered to induce neuroinflammation. The concentrations of cytokines (IL-6, IL-10, and TNF-α) and activities of antioxidant system components (CAT, SOD, GR, NO, and MDA) were measured in the mouse brains. The chemical composition was determined using chromatographic and nuclear magnetic resonance techniques. Results: T1.1, T2.1, and T3.1 showed anti-inflammatory (Ei = 92.5, 88.3, and 64.8%, respectively) and neuroprotective (LT = 27.2, 22.9, and 27.7 s, respectively) effects. T1.1 was identified as scopolin with immunomodulatory (IL-6 = 3307 pg/g) and antioxidant (CAT = 1198 mmol, SOD = 23%, GR = 5.34 units/mL, NO = 11.5 µM, MDA = 1526 nmol/mL) effects; T2.1 was a mixture of terpenes (fitone, 7-dehydrodiosgenin, tremulone) with immunomodulatory (TNF-α = 857 pg/g) and antioxidant (CAT = 1245 mmol, NO = 8.75 µM) effects; and T3.1 was a mixture of isoquercetin and astragalin with immunomodulatory (IL-6 = 3135 pg/g, IL-10 = 1300 pg/g, TNF-α = 751 pg/g) and antioxidant (SOD = 1204 nmol/mL, CAT = 1131 nmol/mL, NO = 6.37 µM, MDA = 1204 nmol/mL) effects. Conclusions: The administration of P. coriacea treatments generated anti-inflammatory, neuroprotective, immunomodulatory, and antioxidant effects. These effects are attributable to its chemical composition, comprising scopolin, terpenes, and a mixture of isoquercetin and astragalin, which have not previously been described in this species.

Excitatory amino acids as therapeutic agents: Reversing neurodegenerative trajectory by tackling excitotoxicity.

Neurodegenerative diseases pose significant challenges to healthcare systems globally due to their complex etiology and relentless progression, often rendering conventional treatments ineffective. Recent advances have spotlighted excitatory amino acids, particularly D-amino acids, once considered as products of metabolism of the microbiota or deriving from food intake. This review explores the role of D-amino acids in mitigating excitotoxicity-a process characterized by excessive calcium influx through aberrant N-methyl-D-aspartate receptor (NMDAR) activation, which is implicated in the pathogenesis of diseases like Alzheimer's disease. By providing alternative pathways for neuronal signaling and protecting against excitotoxic damage, D-amino acids offer a novel approach to reversing neurodegenerative trajectories. Future research should focus on elucidating the detailed mechanisms of action of these compounds, evaluating their therapeutic potential through rigorous preclinical and clinical trials, and developing effective delivery systems to optimize their neuroprotective effects. This emerging field holds promise for developing innovative treatment strategies that could significantly improve outcomes for patients with neurodegenerative disorders.

Tetramethylpyrazine inhibits ferroptosis in spinal cord injury by regulating iron metabolism through the NRF2/ARE pathway

BackgroundTetramethylpyrazine (TMP) is a natural alkaloid compound with antioxidant and neuroprotective effects. We hypothesized that TMP could exert neuroprotective effects by inhibiting ferroptosis through modulating iron metabolism, but its mechanism is unclear. Through in vivo and in vitro experiments, we have explored how TMP can regulate neurons’ iron metabolism through the NRF2/ARE pathway to Inhibit ferroptosis.MethodsIn the in vivo experiment, the effects of TMP on nerve function and secondary spinal cord injury were observed through behavioral tests and morphology staining. Transmission electron microscopy, molecular biology tests and immunofluorescence staining were used to investigate the role of TMP in the regulation of iron metabolism and ferroptosis through the Nrf2/ARE pathway. Using in vitro experiments to investigate the mechanism of TMP in inhibiting ferroptosis through the Nrf2/ARE pathway.ResultsFirstly, through in vivo experiments, we found that TMP improves motor function of rats with spinal cord injury, reduces spinal cord tissue damage and nerve cell death caused by secondary injury. Moreover, neuronal death and the formation of spinal cord cavities are inhibited by TMP. By regulating lipid peroxidation, TMP can inhibit mitochondrial damage and reduce ROS accumulation. Our study also demonstrated that TMP regulates iron metabolism through the NRF2/ARE pathway to inhibit ferroptosis and repair spinal cord injury. To further explore the regulatory mechanisms of TMP we down-regulating Nrf2 expression in subsequent in vitro experiments. We find that a key ferroptosis pathway, lipid peroxidation, can be regulated by TMP. Additionally, TMP inhibits iron overload-mediated ferroptosis by increasing Nrf2 transcriptional activity.ConclusionA regulatory effect of TMP on the NRF2/ARE pathway was found in both in vitro and in vivo experiments. It promotes the transcription and translation of iron metabolizing and antioxidant molecules. Our study explored the inhibitory effect of TMP on ferroptosis from the iron metabolism pathway and provided new ideas for the treatment of SCI.

Hesperetin attenuates neuroprotective effect against 3-Nitropropionic acid induced Huntington’s disease-like behavioral symptoms in rats

The disease Huntington’s (HD) is an autosomal neurologic disorder characterized by inexorable loss of nerve cells in the brain accompanied with cognitive, motor and psychiatric disorders. In the present study, 3-Nitropropionic acid (3-NP), an inhibitor of mitochondrial citric acid cycle results in symptoms like HD. Hesperetin(HSP) is a flavanone rich in citrus species which possess neuroprotective effects. The aim of the present study was to evaluate the protective role of HSP against 3-NP induced symptoms. Pre-treatment of animals with HSP/normal saline for 7 days and from 8th day, 3-NP (10mg/kg) was co-administered with HSP. It is continued for 21 days of the treatment schedule. At the end day of the study, the results showed that HSP improved all the cognitive, motor and psychiatric symptoms induced by 3-NP significantly. Hence, these findings show the protective effect of HSP against 3-NP induced neurological disorder. Keywords: Huntington’s disease, Hesperetin, 3-Nitropropionic acid,

Plant derived bioactive compounds for the treatment of neurodegeneration and neuroimmune disorders associated with the complement system

The complement system is a key component of the innate immune system that mediates the clearance of pathogens, apoptotic cells, and cellular debris. However, the complement system also has diverse roles in the central nervous system (CNS), where it regulates synaptic pruning, neural plasticity, and neuroinflammation. Dysregulation of the complement system has been implicated in various neurodegenerative disorders such as Alzheimer’s disease, multiple sclerosis, epilepsy, stroke, and traumatic brain injury. In these conditions, excessive or chronic activation of the complement system may lead to synaptic loss, neuronal damage, immune dysregulation, and inflammation, which leads to exacerbating the disease’s progression and severity. Moreover, the complement system may interact with infectious agents that invade the CNS, such as bacteria, viruses, fungi, and parasites, and modulate their pathogenicity and host response. Therefore, understanding the complex interplay between the complement system and the CNS is crucial for developing novel therapeutic strategies to prevent or treat neurodegenerative and neuroimmune disorders. Natural compounds, such as plant extracts, phytochemicals, and nutraceuticals, have emerged as promising candidates for modulating the complement system and its effects on the CNS. These compounds may exert anti-inflammatory, antioxidant, neuroprotective, and immunomodulatory effects by regulating the expression of various complement components and pathways. In this review, we summarized the current knowledge on the roles of the complement system in human neurodegenerative disorders and the benefits of natural compounds for complement-targeted therapy.

Development of a Water-Soluble Nanomicellar Formulation Loaded with Trans-Resveratrol Using Polyethylene Glycol Monostearate for the Treatment of Intracerebral Hemorrhage

Background/Objectives: Trans-resveratrol (Res) has been reported to possess many biological activities, including neuroprotective effects, owing to its anti-inflammatory and antioxidant properties. However, Res has very low water solubility, which limits its therapeutic application. In this work, we formulated water-soluble micellar formulations incorporating Res using polyethylene glycol monostearate (stPEG). Methods: These formulations (stPEG/Res) were developed using five types of stPEG containing 10, 25, 40, 55 and 140 PEG repeat units. The formulations were characterized for Res content, water solubility, particle size, zeta potential, precipitation, biodistribution, and efficacy against neuronal and motor dysfunction in intracerebral hemorrhage (ICH). Results: Intravenous administration of stPEG40/Res, which demonstrated particle size, water solubility, and biodistribution properties suitable for intravenous administration, suppressed neurological and motor dysfunction following in a collagenase-induced ICH mouse model. These effects were inhibited by zinc protoporphyrin-9, an inhibitor of the antioxidant enzyme heme oxygenase-1, suggesting that Res contributes to antioxidant enzyme expression and anti-inflammatory activity. Conclusions: The stPEG/Res micellar formulation developed in this study may offer a promising therapeutic approach for ICH treatment.

Analysis of Microheterogeneous Glutelin Subunits and Highly Efficient Identification of Selenylation Peptides by In-Gel Proteolysis: Focus on Se-Enriched Rice.

Selenylation of cysteine and methionine thiols through selenate supplements increases the content of selenium-containing amino acids in various agricultural products. This modification results in numerous biological and health benefits. Despite their critical roles in human physiology, methods for high-coverage and efficient identification of selenylation peptides are limited. This study systematically developed a mass spectrometric method to identify selenylation peptides combined with in-gel trypsin proteolysis. In-gel proteolysis identified the two well-separated bands containing rice glutelin. We identified 11 rice glutelin subunits along with 42 selenylation peptides from the glutelin acidic subunits and 30 selenylation peptides from the glutelin basic subunits with high confidence. A comprehensive evaluation disclosed the mapping of selenium-containing rice glutelin subunits. Additionally, the selenylation modification of peptides coexisted with oxidation and iodoacetamide (IAM) alkylation. Moreover, the multidimensional MS criteria validated the results, while spectral statistics revealed the veritable Se/S substitution degree in Se-enriched rice. These findings collectively demonstrated the presence of numerous selenation sites in microheterogeneous glutelin subunits, thereby enhancing our understanding of the seleno-peptidomics of rice proteins. As significant bioactive organic compounds, the identified peptides in this study are promising candidates for a variety of bioactivities, including neuroprotective, anti-inflammatory, antioxidant, hepatoprotective, and immunomodulatory effects.

Lactobacillus Helveticus Improves Controlled Cortical Impact Injury-Generated Neurological Aberrations by Remodeling of Gut-Brain Axis Mediators.

Considerable studies augured the potential of gut microbiota-based interventions in brain injury-associated complications. Based on our earlier study results, we envisaged the sex-specific neuroprotective effect of Lactobacillus helveticus by remodeling of gut-brain axis. In this study, we investigated the effect of L. helveticus on neurological complications in a mouse model of controlled cortical impact (CCI). Adult, male and female, C57BL/6 mice underwent CCI surgery and received L. helveticus treatment for six weeks. Sensorimotor function was evaluated via neurological severity score and rotarod test. Long-term effects on anxiety-like behavior and cognition were assessed using the elevated-zero maze (EZM) and novel object recognition test (NORT). Brain perilesional area, blood, colon, and fecal samples were collected post-CCI for molecular biology analysis. CCI-operated mice displayed significant neurological impairments at 1-, 3-, 5-, and 7-days post-injury (dpi) and exhibited altered behavior in EZM and NORT compared to sham-operated mice. However, these behavioral changes were ameliorated in mice receiving L. helveticus. GFAP, Iba-1, TNF-α, and IL-1β expressions and corticotrophin-releasing hormone (CRH) levels were elevated in the perilesional cortex of CCI-operated male/female mice. These elevated biomarkers and decreased BDNF levels in both male/female mice were modified by L. helveticus treatment. Additionally, L. helveticus treatment restored altered short-chain fatty acids (SCFAs) levels in fecal samples and improved intestinal integrity but did not affect decreased plasma levels of progesterone and testosterone in CCI mice. These results indicate that L. helveticus exerts beneficial effects in the CCI mouse model by mitigating inflammation and remodeling of gut microbiota-brain mediators.

Capsaicin Protects Against Nigrostriatal Neurodegeneration Induced by Rotenone

Capsaicin, the principal pungent ingredient of hot pepper exerts neuroprotective effects. In this study, the effect of capsaicin on rotenone-induced Parkinson’s disease in mice was investigated. Mice were given subcutaneous rotenone injections (1.5 mg/kg, every other day) and at the same time treated with the vehicle, L-dopa (25 mg/kg) or capsaicin at doses of 0.5 or 1.0 mg/kg orally once a day for two weeks. Biochemical indices of oxidative stress, malondialdehyde, reduced glutathione and nitric oxide were determined in brain tissue and histopathological study of the brain was done. Behavioral tests included stair, wire hanging and wood walking tests. Results showed that rotenone treatment led to significant increases in brain malondialdehyde and nitric oxide contents parallel with marked depletion of reduced glutathione. Rotenone induced degeneration of pigmented neurons in substantia nigra and of cerebral cortex and hippocampus neurons. Rotenone impaired neuromuscular strength, motor balance and coordination. Treatment with capsaicin significantly ameliorated the neuronal degeneration caused by rotenone and improved motor function. Capsaicin alleviated the increase in lipid peroxidation (malondialdehyde) and nitric oxide and prevented the depletion of reduced glutathione in brain of rotenone-treated animals. These data indicate that capsaicin protects against rotenone-induced neuronal damage and this involves decreased level of oxidative stress. Capsaicin therefore might prevent cell death in the brain of Parkinson’s disease patients.

Neuroprotective Effects of Thymol and p-Cymene in Immobilized Male rats through Alterations in Molecular, Biochemical, Histological, and Behavioral Parameters.

The research was conducted to examine the neuroprotective effect of thymol and its precursor p-cymene on chronic immobility stress in adult male Wistar rats. The rats were subjected to 2.5h of stress every day for 14 consecutive days by placing them inside a restrainer. Thymol (10mg/kg) and p-cymene (50mg/kg) were given to the rats during the same period. The results showed that thymol and p-cymene prevented the increase of MDA level, decline of GSH level, and decrease of SOD and GPx activity in the hippocampus of rats exposed to stress. These monoterpenes also prevented the increase in the expression of Tnfa, Il1b, Tlr4, and Nfkb, and the decrease in the expression of Nrf2, Ho1, and Bdnf. In addition, thymol and p-cymene inhibited the increase in the expression and activity of acetylcholinesterase in the hippocampus of animals exposed to immobility and enhanced the expression of A7nachr. They also reduced neuronal death in the CA1 region of stressed animals and improved their performance in the Morris water maze and elevated plus maze tests. Based on these findings, thymol and p-cymene may be effective in preventing neurodegenerative diseases as they reduce oxidative stress and neuroinflammation, strengthen ACh signaling, and stimulate Bdnf expression.

Periplaneta americana L. extract exerts neuroprotective effects by inhibiting endoplasmic reticulum stress via AKT-dependent pathway in experimental models of Parkinson's disease.

Parkinson's disease (PD) is a chronic neurodegenerative disorder that currently has no curable strategies. More and more evidence suggests that endoplasmic reticulum (ER) stress plays an essential role in PD pathogenesis. Periplaneta americana L. (P. americana) is a traditional Chinese medicine with diverse therapeutic properties. This study aims to investigate the neuroprotective effect and underlying mechanism of P. americana in in vitro and in vivo PD models. The exposure of SH-SY5Y cells to 1-methyl-4-phenyl-pyridinium (MPP+) was used as the in vitro PD model. MTT assay, Hoechst staining, Calcein AM-PI staining and flow cytometry were performed to measure the cell viability and apoptosis. DCFH-DA and JC-1 assay were used to measure the intracellular ROS and mitochondrial membrane potential (Δψm), respectively. Western-blot and immunostaining were conducted to detect the expression of key molecules related with ER stress. For the in vivo PD model induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydro-pyridine (MPTP), the motor function of mice was assessed by behavioral tests, the level of TH was examined by western-blot and immunostaining, the expression of key molecules related with ER stress was measured by western-blot. Periplaneta americana ethanol extract (PAE) concentration-dependently inhibited MPP+-induced cell loss and increased cell viability. PAE also remarkably attenuated ROS accumulation, the decline of Δψm as well as the excessive ER stress. The neuroprotective effects of PAE could be blocked by ROS inducer trimethylamine N-Oxide or ER stress activator tunicaymycin, while the antioxidant N-Acetyl-L-cysteine or ER stress inhibitor sodium 4-phenylbutyrate mimicked the effects of PAE. Furthermore, we found that PAE could activate AKT/GSK3β/β-catenin pathway. The effect of PAE on ROS production, Δψm and ER stress was blocked by AKT inhibitor MK-2206. In in vivo model, PAE significantly improved motor function, prevented dopaminergic neuronal loss and attenuated ER stress in substantia nigra and striatum of MPTP-treated mice. Similarly, the effects of PAE on MPTP-treated mice were also abolished by MK-2206. Our results suggest that P. americana exerts neuroprotective effects through inhibiting ER stress via AKT-dependent pathway. Periplaneta americana may represent a promising therapeutic agent for PD treatment and is worthy of further being exploited.

An increase of lysosomes through EGF-triggered endocytosis attenuated zinc-mediated lysosomal membrane permeabilization and neuronal cell death.

In the context of acute brain injuries, where zinc neurotoxicity and oxidative stress are acknowledged contributors to neuronal damage, we investigated the pivotal role of lysosomes as a potential protective mechanism. Our research commenced with an exploration of epidermal growth factor (EGF) and its impact on lysosomal dynamics, particularly its neuroprotective potential against zinc-induced cytotoxicity. Using primary mouse cerebrocortical cultures, we observed the rapid induction of EGFR endocytosis triggered by EGF, resulting in a transient increase in lysosomal vesicles. Furthermore, EGF stimulated lysosomal biogenesis, evident through elevated expression of lysosomal-associated membrane protein 1 (LAMP-1) and the induction and activation of prominent lysosomal proteases, particularly cathepsin B (CTSB). This process of EGFR endocytosis was found to promote lysosomal augmentation, thus conferring protection against zinc-induced lysosomal membrane permeabilization (LMP) and subsequent neuronal death. Notably, the neuroprotective effects and lysosomal enhancement induced by EGF were almost completely reversed by the inhibition of clathrin-mediated and caveolin-mediated endocytosis pathways, along with the disruption of retrograde trafficking. Furthermore, tyrosine kinase inhibition of EGFR nullified EGFR endocytosis, resulting in the abrogation of EGF-induced lysosomal upregulation and neuroprotection. An intriguing aspect of our study is the successful replication of EGF's neuroprotective effects through the overexpression of LAMP-1, which significantly reduced zinc-induced LMP and cell death, demonstrated in both primary mouse cerebrocortical neuronal cultures and human embryonic kidney (HEK) cells. Our research extended beyond zinc-induced neurotoxicity, as we observed EGF's protective effects against other oxidative stressors linked to intracellular zinc release, including hydrogen peroxide (H2O2) and 1-methyl-4-phenylpyridinium ion (MPP+). Collectively, our findings unveil the intricate interplay between EGF-triggered EGFR endocytosis, lysosomal upregulation, an increase in the regulatory capacity for zinc homeostasis, and the subsequent alleviation of zinc-induced neurotoxicity. These results present promising avenues for therapeutic interventions to enhance neuroprotection by targeting lysosomal augmentation.

Semaglutide promotes the transition of microglia from M1 to M2 type to reduce brain inflammation in APP/PS1/tau mice.

A growing number of studies show that the diabetes drug Semaglutide is neuroprotective in Alzheimer's disease (AD) animal models, but its mode of action is not fully understood. In order to explore the mechanism of Semaglutide, 7-month-old APP/PS1/tau transgenic (3xTg) mice and wild-type (WT) mice were randomly divided into four groups: control group (WT + PBS), AD model group (3xTg + PBS), Semaglutide control group (WT + Semaglutide) and Semaglutide treatment group (3xTg + Semaglutide). Semaglutide (25 nmol/kg) or PBS was administered intraperitoneally once every two days for 30 days, followed by behavioral and molecular experiments. The results show that Semaglutide can improve working memory and spatial reference memory of 3xTg-AD mice, promote the release of anti-inflammatory factors and inhibit the production of pro-inflammatory factors in the cortex and hippocampus, and reduce Aβ deposition in the hippocampal CA1 region of 3xTg mice. Semaglutide can inhibit the apoptosis of BV2 cells induced by Aβ1-42 in a dose-dependent manner and promote the transformation of microglia from M1 to M2, thereby exerting anti-inflammatory and neuroprotective effects. Therefore, we speculate that Semaglutide shows an anti-inflammatory effect by promoting the transformation of microglia from M1 to M2 type in the brain of 3xTg mice, and thus exerts a neuroprotective effect.

In-Silico discovery of 17alpha-hydroxywithanolide-D as potential neuroprotective allosteric modulator of NMDA receptor targeting Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder marked by cognitive decline, memory impairment, and behavioral alterations. The N-methyl-D-aspartate (NMDA) receptor has emerged as a promising target for AD pharmacotherapy due to its role in the disease's pathogenesis. This study leverages advanced computational methods to screen 80 active constituents of Withania somnifera (Ashwagandha), a traditional herb known for its neuroprotective effects, against the NMDA receptor, using FDA-approved Ifenprodil as a reference. Our blind virtual screening results demonstrated that all tested compounds could bind to various domains of the NMDA receptor, with binding energies ranging from - 4.1 to -11.9kcal/mol, compared to Ifenprodil's -7.8kcal/mol. Binding preference analysis revealed 7 compounds bound to the A-chain, 37 to the B-chain, 7 to the C-chain, and 29 to the D-chain of the receptor. Notable binding was observed predominantly at the Amino Terminal Domain (ATD) core site, some at the ATD-Ligand Binding Domain (LBD) interface, and a few at the Transmembrane Domain (TMD). Particularly, 17alpha-hydroxywithanolide D, with a binding energy of -11.9kcal/mol, emerged as a prime candidate for further investigation. Molecular dynamics simulations of this compound revealed key interactions, including direct hydrogen bonding with residues ASP165, ARG431, THR433, LYS466, and TYR476 on the D-chain, as well as additional hydrophobic and water-bridging interactions. These simulations highlighted the compound's influence on dynamic conformational states of the GluN1b-GluN2B receptor complex, modulating interactions between GluN1b Lys178 and GluN2B Asn184. Furthermore, the compound affected the distance between LBD heterodimers and the tension within the LBD-M30 linker, demonstrating its potential to modulate NMDA receptor activity. This comprehensive study not only underscores the therapeutic promise of Withania somnifera derivatives for AD but also provides a detailed molecular basis for their efficacy, offering valuable insights for targeted drug development and innovative therapeutic strategies against Alzheimer's disease.