Natural products attenuate PI3K/Akt/mTOR signaling pathway: A promising strategy in regulating neurodegeneration

Research on the protective effect of Rhizoma of Anemarrhena asphodeloides on TMT induced AD mice model based on network pharmacology combined with in vitro and in vivo experimental validation

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease, and neuroprotection is an important approach to improving AD outcomes. Rhizoma of Anemarrhena asphodeloides (RAA) is a commonly used Traditional Chinese Medicine (TCM) with demonstrated neuroprotective effects, but its anti-AD mechanism requires further exploration.

AIM OF THE STUDY

To elucidate the neuroprotective mechanism of RAA on TMT-induced AD mice.

MATERIALS AND METHODS

The AD mice model was established via intraperitoneal injection of TMT. The effect of RAA on ameliorating learning and memory was assessed using the Morris Water Maze (MWM) and Y-maze tests. Haematoxylin-Eosin (HE), Nissl, and TUNEL staining were used to observe the neuroprotective effect of RAA. The components in serum containing RAA (RAA-S) were detected using UPLC-Q-Orbitrap MS. Potential targets were predicted through network pharmacology and molecular docking. Serum levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GPx) were measured with ELISA kits. The HT22 hippocampal neuronal cell line injured by l-glutamate (L-Glu) was used to further elucidate the mechanism of RAA. ROS levels in HT22 cells were detected with the 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe and flow cytometry. Apoptosis in HT22 cells was measured by flow cytometry. The proteins MAP2, GAP-43, Nrf2, Keap1, HO-1, Bax, and Bcl-2 were detected by Western blotting. Immunofluorescence staining was employed to observe Nrf2 nuclear translocation.

RESULTS

RAA significantly increased the residence time of mice in the W zone and enhanced the correct alternation rate in TMT-treated mice. RAA preserved the integrity and orderly arrangement of nerve cells. A total of 12 components were detected in RAA-S. AKT1, PPARG, CASP3, STAT3, HSP90AA1, and NFE2L2 (Nrf2) were involved in the RAA-S target pathway network. Molecular docking revealed that Nrf2 exhibited the highest average binding energy with all components in RAA-S. In vivo, RAA elevated MAP2, GAP-43, Nrf2, and HO-1 levels, along with GPx, GSH, and SOD activity, which had been reduced by TMT. Additionally, RAA reduced serum levels of MDA and ROS, which had been elevated by TMT. In vitro, RAA-S reduced HT22 cell apoptosis and ROS accumulation caused by TMT. Furthermore, RAA-S promoted the expression of N-Nrf2 and HO-1 in L-Glu-injured HT22 cells.

CONCLUSION

RAA attenuated oxidative stress induced by TMT and L-Glu in AD model mice. The underlying mechanism was associated with the activation of the Nrf2/Keap1-HO-1 pathway.

Network pharmacology combined with experimental verification for exploring the potential mechanism of phellodendrine against depression

The anti-inflammatory effect of phellodendrine (PHE), derived from Phellodendri Chinensis Cortex, has been verified in previous studies. Major depressive disorder (MDD) is associated with immune dysregulation and inflammatory processes. This study aimed to explore the therapeutic effects of PHE on MDD through network pharmacology and experimental validation. Multiple databases were used to predict the targets of PHE and MDD. The intersection targets between PHE and MDD were obtained to identify as targets for PHE against MDD, followed by protein-protein interaction network, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Molecular docking was applied to further confirm the anti-MDD effects of PHE. The mitochondrial DNA (mtDNA) copy number, inflammatory cytokines and pathway-related mRNA expressions in PC12 cell were determined via quantitative PCR (qPCR) and enzyme-linked immunosorbent assay to verify our finding. Thirty-eight intersection targets were obtained between PHE and MDD. PHE exerted an anti-MDD effect by regulating SLC6A4, SLC6A3, SLC6A2, MAOA and other targets through serotonergic synapse, salivary secretion, dopaminergic synapse, and cAMP signalling pathway. In vitro, PHE induced an increment in mtDNA copy number compared with the CORT group. PHE affected the levels of IL6 and IL1β with different concentrations. The mRNA levels of CHRM1, HTR1A and key targets of the PI3K/Akt signalling pathway were also influenced. Our research reveals novel mechanisms underlying the anti-MDD effects of PHE through network pharmacology and experiments, which provides a new direction for the development of antidepressants.

Maternal Bisphenol A Exposure Induces Hippocampal-Dependent Learning and Memory Deficits Through the PI3K/Akt/mTOR Pathway in Male Offspring Rats

Bisphenol A (BPA), an environmental endocrine disrupting chemical, is one of the most widely used chemicals in the world and is widely distributed in the external environment, specifically in food, water, dust, and soil. BPA exposure is associated with abnormal cognitive behaviors. However, the underlying mechanism remains unclear. In this study, pregnant female Sprague Dawley rats were orally exposed to BPA at a low dose of 0, 0.04, 0.4, or 4 mg per kg·of body weight per day from embryonic Day 0 (ED 0) to postnatal Day 21 (PND 21). Spatial learning and memory were measured via a Morris water maze test on PND 22. PI3K/Akt/mTOR signaling pathway protein expression was detected in the hippocampi of male offspring using a western blot. The water maze test demonstrated that BPA exposure considerably reduced the learning and memory capacities of the male offspring exposure groups when compared to the control group. The male offspring rats' latency to escape increased significantly, the time taken to traverse a platform reduced, and latency to find a hidden platform showed an increasing trend. Meanwhile, maternal exposure to BPA downregulated the expression of PI3K/Akt/mTOR/p70S6K pathway in the hippocampi of the offspring. Moreover, BPA exposure improved the GSK3β and phosphorylated tau protein (T231) levels, increased malondialdehyde levels, and activated caspase-3 expression in the hippocampi of the male offspring rats. Taken together, these findings indicate that maternal exposure to BPA causes learning and memory impairment and that the PI3K/Akt/mTOR pathway participates in the mechanism of BPA-induced neurocognitive decline.

Potential Protective Effects of Pungent Flavor Components in Neurodegenerative Diseases

Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) have become a major global health burden, but the detailed pathogeneses of neurodegenerative diseases are still unknown, and current treatments are mainly aimed at controlling symptoms; there are no curative treatments for neurodegenerative diseases or treatments for the progressive cognitive, behavioral, and functional impairments that they cause. Studies have shown that some plant extracts with pungent flavor components have a certain neuroprotective effect in neurodegenerative diseases, and their mechanisms mainly involve inhibiting neuronal apoptosis, promoting neuronal regeneration, reducing mitochondrial degeneration, and reducing the production of oxides such as reactive oxygen species in cells, which are of great significance for exploring the treatment of neurodegenerative diseases. In this review, we searched the PubMed database for relevant literature collected in the past 15 years. Finally, we summarized the protective effects of pungent flavor components such as capsaicin, piperine, curcumin, cannabinoids, allicin, and nicotine on the nervous system, focusing on the molecular mechanisms and signaling pathways that they activate. In addition, we also compiled and summarized the laboratory experiments, preclinical experiments, and effects of various pungent flavor components in neurodegenerative diseases. The goal is to further explore their potential as effective drugs for the treatment of neurodegenerative diseases and provide new ideas for further research on the specific protective mechanisms of these substances for the treatment of neurodegenerative diseases and the targets of drug action in the future.

Wogonin mitigates microglia-mediated synaptic over-pruning and cognitive impairment following epilepsy

BACKGROUND

Epilepsy, a neurological disorder characterized by recurrent abnormal neuronal discharges, leading to brain dysfunction and imposing significant psychological and economic burdens on patients. Microglia, the resident immune cells within the central nervous system (CNS), play a crucial role in maintaining CNS homeostasis. However, activated microglia can excessively prune synapses, exacerbating neuronal damage and cognitive dysfunction following epilepsy. Wogonin, a flavonoid from Scutellaria Baicalensis, has known neuroprotective effects via anti-inflammatory and antioxidative mechanisms, but its impact on microglial activation and synaptic pruning in neurons post-epilepsy remains unclear.

METHODS

Synaptic density was assessed using presynaptic marker Synaptophysin and postsynaptic marker Psd-95, and microglial phagocytosis was evaluated with fluorescent microspheres. Pilocarpine-induced mouse model of status epilepticus was used to evaluate synaptic density changes of mouse hippocampus following an intraperitoneal injection of wogonin (50 and 100 mg/kg). Memory and cognitive function in mice were subsequently evaluated using the Y-maze, object recognition, and Morris water maze tests. Single-cell sequencing was employed to investigate the underlying causes of microglial state alterations, followed by experimental validation.

RESULTS

Microglia were transitioned to an activated state post-epilepsy, exhibiting significantly enhanced phagocytic capacity. Correspondingly, levels of synaptophysin and Psd-95 were markedly reduced in neurons. Treatment with wogonin (100 mg/kg) significantly increased neuronal synaptic density and improved learning and memory deficits in epileptic mice. Further investigation revealed that wogonin inhibits the release of pro-inflammatory cytokines and synaptic phagocytosis of microglia by activating the AKT/FoxO1 pathway.

CONCLUSIONS

Wogonin could alleviate excessive synaptic pruning of epileptic neurons by microglia and improve cognitive dysfunction of epileptic mice via the AKT/FoxO1 pathway.

Neuroprotective effects of Elaeagnus glabra f. oxyphylla extract in amyloid-beta-induced cognitive deficit mice: Involvement of the PKC-delta, MYL2, and FER pathways

Elaeagnus glabra f. oxyphylla (EGFO), a member of the Elaeagnaceae family, is an evergreen plant distinct from other species in its genus. We previously reported that ethanol extract from EGFO has memory improvement effects in a short-term memory deficit mouse model and anti-inflammatory effects in a microglial cell line. However, little is known about the pharmacological effects of EGFO. In the present study, we further explored the effect of EGFO on cognitive impairment using amyloid-beta-induced Alzheimer's disease (AD)-like mice. EGFO extract significantly enhanced cognitive functions in the passive avoidance task and Morris water maze test. EGFO treatment led to a significant increase in neuronal nuclei expression in mouse hippocampal tissues and inhibited hydrogen peroxide-induced cell death in HT22 hippocampal cells, indicating the neuroprotective effects of EGFO. Antibody microarray analysis was performed to determine the molecular mechanisms underlying the effects of EGFO on cognitive improvement and neuroprotection. The data revealed that EGFO decreased the phosphorylation of protein kinase C delta and increased the phosphorylation of myosin regulatory light chain 2 and tyrosine kinase Fer. These findings were validated using immunoblotting both in in vitro and in vivo AD models. Overall, our findings suggest that EGFO could be a candidate therapeutic agent for AD or AD-like diseases due to its potential for cognitive improvement and neuroprotection.

Neuroprotective effects of resveratrol through modulation of PI3K/Akt/GSK-3β pathway and metalloproteases

To analyze the expressional changes in the PI3K/Akt/GSK-3β pathway and metalloprotease in the cellular Alzheimer's Disease (AD) model with the effect of antioxidant resveratrol. Neuron-like cells were obtained by a two-step method of neuronal differentiation by using a combination of retinoic acid (RA) and brain-derived factor (BDNF) exposure. Then, the application of the amyloid beta peptide 25-35 (Aβ25-35) to the cell culture mimicked the environmental toxicity observed in AD. Afterward, cell viability and apoptosis assays were performed to determine whether the resveratrol exerts a cytotoxic and apoptotic effect. Finally, the expressional changes in genes in the cellular AD model with the effect of resveratrol were analyzed by Real-Time PCR. The analysis in silico was assessed using the STRING V12.0 database in each group. Apoptosis data findings were decreased by 1.5-fold and 2.5-fold respectively by Differentiated+Resveratrol (RES) and RES when compared to control but no significant difference was observed between RES and AD model groups. Real-time PCR analysis results revealed PI3K (3.38-fold), AKT (3.95-fold), and RELN (1.99-fold) expressions were significantly higher (p < .001), and also GSK-3β, TAU, ADAMTS-4, ADAMTS-5, and TIMP-3 gene expression levels were significantly downregulated (2.53-, 1.79-, 2.85-, 4.09-, and 6.62-fold, respectively) in the Differentiated+Aβ + RES groups compared to the Differentiated+Aβ group (p < .001). Network analysis shows the functional enrichment of 23 Alzheimer-related GO terms in the Wnt signaling, proteolysis, and extracellular matrix organization pathways. Resveratrol has inhibited GSK-3β by activating the PI3K/Akt insulin pathway in a neurotoxic environment. In addition, TAU, RELN, metalloproteases, and their inhibitors associated with Alzheimer's pathology have been regulated supporting the neuroprotective effect of resveratrol.

Luteolin prevents cadmium-induced PC12 cell death by suppressing the Akt/mTOR signaling pathway

Cadmium (Cd) is an environmental pollutant that can cause neurodegenerative disorders. Luteolin (Lut) is a natural flavonoid compound. However, whether Lut protects against Cd-induced nerve cell death remains unclear. In the present study, PC12 cells were used to investigate the neuroprotective effect of Lut against Cd poisoning. Changes in cell viability, apoptosis, B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein expression, and protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway activity were analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Hoechst 33258 staining, flow cytometry, and western blotting. Lut markedly attenuated the Cd-induced reduction in cell viability, nuclear fragmentation, condensation, and the decrease in the Bcl-2/Bcl-2-associated X protein ratio in PC12 cells. Furthermore, Lut blocked the Cd-mediated activation of the Akt/mTOR signaling pathway. Moreover, inhibition of the Akt/mTOR signaling pathway with LY294002 (a PI3K inhibitor) enhanced the protective effect of Lut against Cd-induced cell death by suppressing Cd-induced activation of Akt, mTOR, and eukaryotic initiation factor 4E binding protein 1. The results showed that Lut prevented Cd-induced cell death partly by blocking the Akt/mTOR signaling pathway. Lut may be a potential agent for preventing Cd-induced nerve cell damage and neurodegenerative diseases.

Rotating magnetic field improves cognitive and memory impairments in APP/PS1 mice by activating autophagy and inhibiting the PI3K/AKT/mTOR signaling pathway

Alzheimer's disease (AD) is a geriatric disorder that can be roughly classified into sporadic AD and hereditary AD. The latter is strongly associated with genetic factors, and its treatment poses greater challenges compared to sporadic AD. Rotating magnetic fields (RMF) is a non-invasive treatment known to have diverse biological effects, including the modulation of the central nervous system and aging. However, the impact of RMF on hereditary AD and its underlying mechanism remain unexplored. In this study, we exposed APP/PS1 mice to RMF (2 h/day, 0.2 T, 4 Hz) for a duration of 6 months. The results demonstrated that RMF treatment significantly ameliorated their cognitive and memory impairments, attenuated neuronal damage, and reduced amyloid deposition. Furthermore, RNA-sequencing analysis revealed a significant enrichment of autophagy-related genes and the PI3K/AKT-mTOR signaling pathway. Western blotting further confirmed that RMF activated autophagy and suppressed the phosphorylation of proteins associated with the PI3K/AKT/mTOR signaling pathway in APP/PS1 mice. These protective effects and the underlying mechanism were also observed in Aβ25-35-exposed HT22 cells. Collectively, our findings indicate that RMF improves cognitive and memory dysfunction in APP/PS1 mice by activating autophagy and inhibiting the PI3K/AKT/mTOR signaling pathway, thus highlighting the potential of RMF as a clinical treatment for hereditary AD.

Identification of significant biomarkers for predicting the risk of bipolar disorder with arteriosclerosis based on integrative bioinformatics and machine learning

Introduction

Increasing evidence has indicated a connection between bipolar disorder (BD) and arteriosclerosis (AS), yet the specific molecular mechanisms remain unclear. This study aims to investigate the hub genes and molecular pathways for BD with AS.

Methods

BD-related dataset GSE12649 were downloaded from the Gene Expression Omnibus database and differentially expressed genes (DEGs) and key module genes derived from Limma and weighted gene co-expression network analyses (WGCNA) were identified. AS-related genes were sourced from the DisGeNET database, and the overlapping genes between DEGs and AS-related genes were characterized as differentially expressed arteriosclerosis-related genes (DE-ASRGs). The functional enrichment analysis, protein-protein interaction (PPI) network and three machine learning algorithms were performed to explore the hub genes, which were validated with two external validation sets. Additionally, immune infiltration was performed in BD.

Results

Overall, 67 DE-ASRGs were found to be overlapping between the DEGs and AS-related genes. Functional enrichment analysis highlighted the cancer pathways between BD and AS. We identified seven candidate hub genes (CTSD, IRF3, NPEPPS, ST6GAL1, HIF1A, SOX9 and CX3CR1). Eventually, two hub genes (CX3CR1 and ST6GAL1) were identified as BD and AS co-biomarkers by using machine learning algorithms. Immune infiltration had revealed the disorder of immunocytes.

Discussion

This study identified the hub genes CX3CR1 and ST6GAL1 in BD and AS, providing new insights for further research on the bioinformatic mechanisms of BD with AS and contributing to the diagnosis and prevention of AS in psychiatric clinical practice.

Phytochemicals regulate cancer metabolism through modulation of the AMPK/PGC-1α signaling pathway

BACKGROUND

Due to the complex pathophysiological mechanisms involved in cancer progression and metastasis, current therapeutic approaches lack efficacy and have significant adverse effects. Therefore, it is essential to establish novel strategies for combating cancer. Phytochemicals, which possess multiple biological activities, such as antioxidant, anti-inflammatory, antimutagenic, immunomodulatory, antiproliferative, anti-angiogenesis, and antimetastatic properties, can regulate cancer progression and interfere in various stages of cancer development by suppressing various signaling pathways.

METHODS

The current systematic and comprehensive review was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) criteria, using electronic databases, including PubMed, Scopus, and Science Direct, until the end of December 2023. After excluding unrelated articles, 111 related articles were included in this systematic review.

RESULTS

In this current review, the major signaling pathways of cancer metabolism are highlighted with the promising anticancer role of phytochemicals. This was through their ability to regulate the AMP-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) signaling pathway. The AMPK/PGC-1α signaling pathway plays a crucial role in cancer cell metabolism via targeting energy homeostasis and mitochondria biogenesis, glucose oxidation, and fatty acid oxidation, thereby generating ATP for cell growth. As a result, targeting this signaling pathway may represent a novel approach to cancer treatment. Accordingly, alkaloids, phenolic compounds, terpene/terpenoids, and miscellaneous phytochemicals have been introduced as promising anticancer agents by regulating the AMPK/PGC-1α signaling pathway. Novel delivery systems of phytochemicals targeting the AMPK/PGC-1α pathway in combating cancer are also highlighted in this review.

Sesamol Alleviates Sarcopenia via Activating AKT/mTOR/FoxO1 Signal Pathway in Aged Obese Mice

Sesamol is a major bioactive component extracted from sesame seeds and has various medicinal properties. However, the effects of sesamol on sarcopenia associated with aging and obesity remains unclear. Therefore, the protective effects and underlying mechanisms of sesamol on sarcopenia was evaluated in aged and obese C57BL/6 J male mouse models fed a high fat diet and C2C12 myotubes co-treated with D-gal and PA in this study. Our in vivo data showed that sesamol activated AKT/mTOR/FoxO1 signal pathway, and then upregulated p-p70S6K and p-4EBP1 to promote myoprotein synthesis, and downregulated Atrogin-1 and MuRF1 to inhibit myoprotein degradation, thus ameliorating sarcopenia related to aging and obesity. Furthermore, our in vitro results confirmed the protective effect and aforementioned mechanisms of sesamol on sarcopenia. Collectively, sesamol could alleviate sarcopenia associated with aging and obesity via activating the AKT/mTOR/FoxO1 signal pathway. Our findings highlight the therapeutic potentials of sesamol for aging and obesity-related metabolic muscular complications.

Daidzein's potential in halting neurodegeneration: unveiling mechanistic insights

Neurological conditions encompassing a wide range of disorders pose significant challenges globally. The complex interactions among signaling pathways and molecular elements play pivotal roles in the initiation and progression of neurodegenerative diseases. Isoflavones have emerged as a promising candidate to fight against neurodegenerative diseases. Daidzein, a 7-hydroxy-3-(4-hydroxyphenyl)-chromen-4-one, belongs to the isoflavone class and exhibits a diverse pharmacological profile. It is found primarily in soybeans and soy products, as well as in some other legumes and herbs. Investigations into daidzein have revealed that it confers neuroprotection by inhibiting oxidative stress, inflammation, and apoptosis, which are key contributors to neuronal damage and degeneration. Activating pathways like PI3K/Akt/mTOR and promoting neurotrophic factors like BDNF by daidzein underscore its potential in supporting neuronal function and combating neurodegeneration. Daidzein's effects on dopamine provide further avenues for intervention in conditions like Parkinson's disease. Additionally, the modulation of inflammatory and NRF-2-antioxidant signaling by daidzein reinforces its neuroprotective role. Moreover, daidzein's interaction with receptors and cellular processes like ER-β, GPR30, MAO, VEGF, and GnRH highlights its multifaceted effects across multiple pathways involved in neuroprotection and neuronal function. This review article delves into the mechanistic interplay of various mediators in mediating the neuroprotective effects of daidzein. The review article consolidates and analyzes research published over nearly two decades (2005-2024) from various databases, including PubMed, Scopus, ScienceDirect, and Web of Science, to provide a comprehensive understanding of daidzein's effects and mechanisms in neuroprotection.

Astaxanthin Rescues Memory Impairments in Rats with Vascular Dementia by Protecting Against Neuronal Death in the Hippocampus

Vascular dementia (VaD) is a cognitive disorder characterized by a decline in cognitive function resulting from cerebrovascular disease. The hippocampus is particularly susceptible to ischemic insults, leading to memory deficits in VaD. Astaxanthin (AST) has shown potential therapeutic effects in neurodegenerative diseases. However, the mechanisms underlying its protective effects in VaD and against hippocampal neuronal death remain unclear. In this study, We used the bilateral common carotid artery occlusion (BCCAO) method to establish a chronic cerebral hypoperfusion (CCH) rat model of VaD and administered a gastric infusion of AST at 25 mg/kg per day for 4 weeks to explore its therapeutic effects. Memory impairments were assessed using Y-maze and Morris water maze tests. We also performed biochemical analyses to evaluate levels of hippocampal neuronal death and apoptosis-related proteins, as well as the impact of astaxanthin on the PI3K/Akt/mTOR pathway and oxidative stress. Our results demonstrated that AST significantly rescued memory impairments in VaD rats. Furthermore, astaxanthin treatment protected against hippocampal neuronal death and attenuated apoptosis. We also observed that AST modulated the PI3K/Akt/mTOR pathway, suggesting its involvement in promoting neuronal survival and synaptic plasticity. Additionally, AST exhibited antioxidant properties, mitigating oxidative stress in the hippocampus. These findings provide valuable insights into the potential therapeutic effects of AST in VaD. By elucidating the mechanisms underlying the actions of AST, this study highlights the importance of protecting hippocampal neurons and suggests potential targets for intervention in VaD. There are still some unanswered questions include long-term effects and optimal dosage of the use in human. Further research is warranted to fully understand the therapeutic potential of AST and its application in the clinical treatment of VaD.

Exploiting new strategies in combating head and neck carcinoma: A comprehensive review on phytochemical approaches passing through PI3K/Akt/mTOR signaling pathway

Recently, malignant neoplasms have growingly caused human morbidity and mortality. Head and neck cancer (HNC) constitutes a substantial group of malignancies occurring in various anatomical regions of the head and neck, including lips, mouth, throat, larynx, nose, sinuses, oropharynx, hypopharynx, nasopharynx, and salivary glands. The present study addresses the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway as a possible therapeutic target in cancer therapy. Finding new multitargeting agents capable of modulating PI3K/Akt/mTOR and cross-linked mediators could be viewed as an effective strategy in combating HNC. Recent studies have introduced phytochemicals as multitargeting agents and rich sources for finding and developing new therapeutic agents. Phytochemicals have exhibited immense anticancer effects, including targeting different stages of HNC through the modulation of several signaling pathways. Moreover, phenolic/polyphenolic compounds, alkaloids, terpenes/terpenoids, and other secondary metabolites have demonstrated promising anticancer activities because of their diverse pharmacological and biological properties like antiproliferative, antineoplastic, antioxidant, and anti-inflammatory activities. The current review is mainly focused on new therapeutic strategies for HNC passing through the PI3K/Akt/mTOR pathway as new strategies in combating HNC.

Potential molecular mechanisms and clinical implications of piRNAs in preeclampsia: a review

Preeclampsia is a multisystem progressive condition and is one of the most serious complications of pregnancy. Owing to its unclear pathogenesis, there are no precise and effective therapeutic targets for preeclampsia, and the only available treatment strategy is to terminate the pregnancy and eliminate the clinical symptoms. In recent years, non-coding RNAs have become a hotspot in preeclampsia research and have shown promise as effective biomarkers for the early diagnosis of preeclampsia over conventional biochemical markers. PIWI-interacting RNAs, novel small non-coding RNA that interact with PIWI proteins, are involved in the pathogenesis of various diseases at the transcriptional or post-transcriptional level. However, the mechanisms underlying the role of PIWI-interacting RNAs in the pathogenesis of preeclampsia remain unclear. In this review, we discuss the findings of existing studies on PIWI-interacting RNA biogenesis, functions, and their possible roles in preeclampsia, providing novel insights into the potential application of PIWI-interacting RNAs in the early diagnosis and clinical treatment of preeclampsia.

FMOD Alleviates Depression-Like Behaviors by Targeting the PI3K/AKT/mTOR Signaling After Traumatic Brain Injury

Depression frequently occurs following traumatic brain injury (TBI). However, the role of Fibromodulin (FMOD) in TBI-related depression is not yet clear. Previous studies have suggested FMOD as a potential key factor in TBI, yet its association with depression post-TBI and underlying mechanisms are not well understood. Serum levels of FMOD were measured in patients with traumatic brain injury using qPCR. The severity of depression was assessed using the self-depression scale (SDS). Neurological function, depressive state, and cognitive function in mice were assessed using the modified Neurological Severity Score (mNSS), forced swimming test (FST), tail suspension test (TST), Sucrose Preference Test (SPT), and morris water maze (MWM). The morphological features of mouse hippocampal synapses and neuronal dendritic spines were revealed through immunofluorescence, transmission electron microscopy, and Golgi-Cox staining. The protein expression levels of FMOD, MAP2, SYP, and PSD95, as well as the phosphorylation levels of the PI3K/AKT/mTOR signaling pathway, were detected through Western blotting. FMOD levels were decreased in TBI patients' serum. Overexpression of FMOD preserved neuronal function and alleviated depression-like behaviour, increased synaptic protein expression, and induced ultrastructural changes in hippocampal neurons. The increased phosphorylation of PI3K, AKT, and mTOR suggested the involvement of the PI3K/AKT/mTOR signaling pathway in FMOD's protective effects. FMOD exhibits potential as a therapeutic target for depression related to TBI, with its protective effects potentially mediated through the PI3K/AKT/mTOR signaling pathway.

TransNeT-CGP: A cluster-based comorbid gene prioritization by integrating transcriptomics and network-topological features

The local disruptions caused by the genes of one disease can influence the pathways associated with the other diseases resulting in comorbidity. For gene therapies, it is necessary to prioritize the key genes that regulate common biological mechanisms to tackle the issues caused by overlapping diseases. This work proposes a clustering-based computational approach for prioritising the comorbid genes within the overlapping disease modules by analyzing Protein-Protein Interaction networks. For this, a sub-network with gene interactions of the disease pair was extracted from the interactome. The edge weights are assigned by combining the pairwise gene expression correlation and betweenness centrality scores. Further, a weighted graph clustering algorithm is applied and dominant nodes of high-density clusters are ranked based on clustering coefficients and neighborhood connectivity. Case studies based on neurodegenerative diseases such as Amyotrophic Lateral Sclerosis- Spinal Muscular Atrophy (ALS-SMA) pair and cancers such as Ovarian Carcinoma-Invasive Ductal Breast Carcinoma (OC-IDBC) pair were conducted to examine the efficacy of the proposed method. To identify the mechanistic role of top-ranked genes, we used Functional and Pathway enrichment analysis, connectivity analysis with leave-one-out (LOO) method, analysis of associated disease-related protein complexes, and prioritization tools such as TOPPGENE and Heml2.0. From pathway analysis, it was observed that the top 10 genes obtained using the proposed method were associated with 10 pathways in ALS-SMA comorbidity and 15 in the case of OC-IDBC, while that in similar methods like SAPDSB and S2B were 4, 6 respectively for ALS-SMA and 9, 10 respectively for OC-IDBC. In both case studies, 70 % of the disease-specific benchmark protein complexes were linked to top-ranked genes of the proposed method while that of SAPDSB and S2B were 55 % and 60 % respectively. Additionally, it was found that the removal of the top 10 genes disconnect the network into 14 distinct components in the case of ALS-SMA and 9 in the case of OC-IDBC. The experimental results shows that the proposed method can be effectively used for identifying key genes in comorbidity and can offer insights about the intricate molecular relationship driving comorbid diseases.

Sub-chronic oral toxicity study of the alkaloid rich fraction from Luffa cylindrica fruit in Sprague-Dawley rats

The loofah/sponge gourd Luffa cylindrica (L.), a member of the Cucurbitaceae family, is one of the neglected medicinal plants. Traditionally, Luffa cylindrica is prescribed for inducing labor. It has a long history of use in China for the treatment of fever, diabetes, dyspnea, and dysentery. This study investigated the toxicity profile of the alkaloid-rich fraction of Luffa cylindrica (ARF-LC) for the first time in Sprague Dawley rats. A total of 80 rats (40 male and 40 female rats) aged 13 weeks old and weighing 200-220 g were selected for this study. In SD rats, sub-chronic oral toxicity was investigated at doses of 100, 200, and 400 mg/kg/d for a total of 90 days, followed by a 30-day recovery period. The results showed no variation in body weight among the three dose groups compared to the control group. Treatment-related adverse events, such as alterations in hematology and serum biochemistry parameters and the histology of the liver were sporadic in the high-dose rats but within the reference range. However, these changes disappeared after the doses were withdrawn during the recovery period. In conclusion, the "no observed adverse effect level" (NOAEL) of oral administration of ARF-LC in SD rats was considered 400 mg/kg/d and can be studied for its potential in further in vivo chronic investigations.

Epigallocatechin gallate protects MC3T3-E1 cells from cadmium-induced apoptosis and dysfunction via modulating PI3K/AKT/mTOR and Nrf2/HO-1 pathways

Epigallocatechin gallate (EGCG), an active constituent of tea, is recognized for its anticancer and anti-inflammatory properties. However, the specific mechanism by which EGCG protects osteoblasts from cadmium-induced damage remains incompletely understood. Here, the action of EGCG was investigated by exposing MC3T3-E1 osteoblasts to EGCG and CdCl2 and examining their growth, apoptosis, and differentiation. It was found that EGCG promoted the viability of cadmium-exposed MC3T3-E1 cells, mitigated apoptosis, and promoted both maturation and mineralization. Additionally, CdCl2 has been reported to inhibit both the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and nuclear factor erythroid 2-related factor 2/heme oxygenase-1(Nrf2/HO-1) signaling pathways. EGCG treatment attenuated cadmium-induced apoptosis in osteoblasts and restored their function by upregulating both signaling pathways. The findings provide compelling evidence for EGCG's role in attenuating cadmium-induced osteoblast apoptosis and dysfunction through activating the PI3K/AKT/mTOR and Nrf2/HO-1 pathways. This suggests the potential of using EGCG for treating cadmium-induced osteoblast dysfunction.

Research on the signaling pathways related to the intervention of traditional Chinese medicine in Parkinson's disease:A literature review

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is the most common progressive neurodegenerative disorder affecting more than 10 million people worldwide and is characterized by the progressive loss of Daergic (DA) neurons in the substantia nigra pars compacta. It has been reported that signaling pathways play a crucial role in the pathogenesis of PD, while the active ingredients of traditional Chinese medicine (TCM) have been found to possess a protective effect against PD. TCM has demonstrated significant potential in mitigating oxidative stress (OS), neuroinflammation, and apoptosis of DA neurons via the regulation of signaling pathways associated with PD.

AIM OF THE REVIEW

This study discussed and analyzed the signaling pathways involved in the occurrence and development of PD and the mechanism of active ingredients of TCM regulating PD via signaling pathways, with the aim of providing a basis for the development and clinical application of therapeutic strategies for TCM in PD.

MATERIALS AND METHODS

With "Parkinson's disease", "Idiopathic Parkinson's Disease", "Lewy Body Parkinson's Disease", "Parkinson's Disease, Idiopathic", "Parkinson Disease, Idiopathic", "Parkinson's disorders", "Parkinsonism syndrome", "Traditional Chinese medicine", "Chinese herbal medicine", "active ingredients", "medicinal plants" as the main keywords, PubMed, Web of Science and other online search engines were used for literature retrieval.

RESULTS

PD exhibits a close association with various signaling pathways, including but not limited to MAPKs, NF-κB, PI3K/Akt, Nrf2/ARE, Wnt/β-catenin, TLR/TRIF, NLRP3, Notch. The therapeutic potential of TCM lies in its ability to regulate these signaling pathways. In addition, the active ingredients of TCM have shown significant effects in improving OS, neuroinflammation, and DA neuron apoptosis in PD.

CONCLUSION

The active ingredients of TCM have unique advantages in regulating PD-related signaling pathways. It is suggested to combine network pharmacology and bioinformatics to study the specific targets of TCM. This not only provides a new way for the prevention and treatment of PD with the active ingredients of TCM, but also provides a scientific basis for the selection and development of TCM preparations.

The polysaccharides from Balanophora polyandra enhanced neuronal autophagy to ameliorate brain function decline in natural aging mice through the PI3K/AKT/mTOR signaling pathway

The decline of aging brain neurons is the main cause of various neurodegenerative disease. This study aimed to examine the impact of Balanophora polyandra polysaccharides (BPP) against aging related neuronal deterioration. C57BL/6 mice were fed with regular feed for 27 months to establish a natural aging mouse model. From 3 months of age, mice in the drug-treated group were respectively fed with feed containing 0.05 or 0.18% BPP until 27 months of age. The effects of BPP treatment on the pathological changes of neurons in mice brain were evaluated, as well as autophagy-related and signaling pathway proteins. BPP treatment had a notable positive impact on the pathological injury of cortical and hippocampal neurons, alleviated neuronal degeneration, and enhanced the staining of Nissl bodies in natural aging mice. Furthermore, BPP upregulated autophagy-related proteins LC3 II/I, Parkin, and PINK1 in the cortex and hippocampus of aging mice, and significantly decreased the expression of p62, PI3K, p-protein Kinase B (AKT), and p-mTOR. Immunofluorescence results showed a reduction in the brightness of LC3, which mainly coexpressed with NeuN in natural aging mice brain, and increased LC3-positive neurons were observed after BPP treatment. Collectively, BPP treatment enhanced neuronal autophagy to improve brain functional degradation through the PI3K/AKT/mTOR signaling in natural aging mice. These finding suggested that BPP has potential to mitigate or delay the neurodegeneration associated with aging and further investigation was needed to validate its efficacy in elderly populations.

PCSK9 induces endothelial cell autophagy by regulating the PI3K/ATK pathway in atherosclerotic coronary heart disease

OBJECTIVE

Atherosclerosis is a chronic inflammatory disease of the arteries, and its pathogenesis is related to endothelial dysfunction. It has been found that the protein convertase subtilin/kexin9 type (PCSK9) plays an important role in AS, but its specific mechanism is still unclear.

METHODS

In this study, we first cultured human umbilical vein endothelial cells (HUVECs) with 50 or 100μg/ml oxidized low-density lipoprotein (ox-LDL) for 24 hours to establish a coronary atherosclerosis cell model.

RESULTS

The results showed that ox-LDL induced HUVEC injury and autophagy and upregulated PCSK9 protein expression in HUVECs in a concentration-dependent manner. Silencing PCSK9 expression with siRNA inhibited ox-LDL-induced HUVEC endothelial dysfunction, inhibited the release of inflammatory factors, promoted HUVEC proliferation and inhibited apoptosis. In addition, ox-LDL increased the expression of LC3B-I and LC3B-II and decreased the expression of p62. However, these processes are reversed by sh-PCSK9. In addition, sh-PCSK9 can inhibit PI3K, AKT and mTOR phosphorylation and promote autophagy.

CONCLUSION

Taken together, our research shows that silencing PCSK9 inhibits the PI3K/ATK/mTOR pathway to activate ox-LDL-induced autophagy in vascular endothelial cells, alleviating endothelial cell injury and inflammation.

Study on characterization of Bupleurum chinense polysaccharides with antioxidant mechanisms focus on ROS relative signaling pathways and anti-aging evaluation in vivo model

This study explored the structures of three polysaccharides from Bupleurum chinense DC. (BCPRs), and evaluated their antioxidant and anti-aging properties. The HPGPC and ion chromatography analyses revealed that the molecular weights of the BCPRs ranged from 12.05 to 21.20 kDa, and were primarily composed of rhamnose, arabinose, xylose, galactose, glucose and galacturonic acid. Methylation and NMR studies identified 10 PMAAs, establishing the various backbones of BCPRs 1-3. BCPR-3 demonstrated potent antioxidant activities, including DPPH, ABTS, hydroxy, and superoxide radicals scavenging in vitro. At concentrations between 125 and 500 μg/mL, BCPR-3 increased T-AOC, SOD and GSH-Px activities, while decreasing MDA levels in H2O2-induced SH-SY5Y cells. In addition, RNA-seq results indicated that BCPR-3 considerably downregulated the expression of 49 genes and upregulated five genes compared with the control group. KEGG analysis suggested that these differentially expressed genes (DEGs) were predominantly involved in the TNF and PI3K/Akt signaling pathways. Furthermore, in vivo experiment with Drosophila melanogaster showed that BCPR-3 could extend the average lifespan of flies. In conclusion, polysaccharides from B. chinense exhibited potential antioxidant and anti-aging activities, which could be developed as new ingredients to combat oxidative stress damage and slow the aging process.

Protective effect of a hydromethanolic extract from Fraxinus excelsior L. bark against a rat model of aluminum chloride-induced Alzheimer's disease: Relevance to its anti-inflammatory and antioxidant effects

ETHNOPHARMACOLOGICAL RELEVANCE

Fraxinus excelsior L. (FE), commonly known as the ash, belongs to the Oleaceae family and has shown several pharmacological and biological properties, such as antioxidant, immunomodulatory, neuroprotective, and anti-inflammatory effects. It has also attracted the most attention toward neuroinflammation. Moreover, FE bark and leaves have been used to treat neurological disorders, aging, neuropathic pain, urinary complaints, and articular pain in traditional and ethnomedicine. Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder resulting from the involvement of amyloid-beta, metal-induced oxidative stress, and neuroinflammation.

AIM OF THE STUDY

The objective of the current study was to assess the neuroprotective effects of hydromethanolic extract from FE bark in an AlCl3-induced rat model of AD.

MATERIALS AND METHODS

The maceration process was utilized to prepare the hydromethanolic extract of FE bark, and characterized by LC-MS/MS. To assess the anti-AD effects of the FE extract, rats were categorized into five different groups, AlCl3; normal control; FE-treated groups at 50, 100, and 200 mg/kg. Passive avoidance learning test, Y-maze, open field, and elevated plus maze behavioral tests were evaluated on days 7 and 14 to analyze the cognitive impairments. Zymography analysis, biochemical tests, and histopathological changes were also followed in different groups.

RESULTS

LC-MS/MS analysis indicated the presence of coumarins, including isofraxidin7-O-diglucoside in the methanolic extract of FE as a new isofraxidin derivative in this genus. FE significantly improved memory and cognitive function, maintained weight, prevented neuronal damages, and preserved the hippocampus's histological features, as demonstrated by behavioral tests and histopathological analysis. FE increased anti-inflammatory MMP-2 activity, whereas it decreased that of inflammatory MMP-9. Moreover, FE increased plasma antioxidant capacity by enhancing CAT and GSH while decreasing nitrite levels in the serum of treated groups. In comparison between the treated groups, the rats that received high doses of the FE extract (200 mg/kg) showed the highest therapeutic effect.

CONCLUSION

FE rich in coumarins could be an effective anti-AD adjunct agent, passing through antioxidant and anti-inflammatory pathways. These results encourage further studies for the development of this extract as a promising agent in preventing, managing, or treating AD and related diseases.

Inhibition of Alzheimer's disease by 4-octyl itaconate revealed by RNA-seq transcriptome analysis

AIMS

This study aimed to examine the therapeutic effects and response mechanisms of 4-OI in Alzheimer's disease (AD).

METHODS

In this study, network pharmacology was employed to analyze potential targets for AD drug therapy. Immunofluorescence and quantitative reverse transcription polymerase chain reaction (qRT-PCR) techniques were utilized to detect inflammatory phenotypes in a 4-OI-resistant mouse microglia cell line (BV2). We conducted four classical behavioral experiments, namely the open field test, new object recognition test, Y maze test, and Morris water maze, to assess the emotional state and cognitive level of APPswe/PS1dE9 (referred to as APP/PS1) mice after 4-OI treatment. Hematoxylin and eosin (HE) staining, along with immunofluorescence staining, were performed to detect amyloid (Aβ) deposition in mouse brain tissue. To explore the potential molecular mechanisms regulating the effects of 4-OI treatment, we performed RNA-SEQ and transcription factor prediction analyses. Additionally, mouse BV2 cells underwent Western blotting analysis to elucidate potential molecular mechanisms underlying the observed effects.

RESULTS

We discovered that 4-OI exerts an inhibitory effect on neuroinflammation by promoting autophagy. This effect is attributed to the activation of the AMPK/mTOR/ULK1 pathway, achieved through enhanced phosphorylation of AMPK and ULK1, coupled with a reduction in mTOR phosphorylation. Furthermore, 4-OI significantly enhances neuronal recovery in the hippocampus and diminishes Aβ plaque deposition in APP/PS1 mice, improved anxiety in mice, and ultimately led to improved cognitive function.

CONCLUSIONS

Overall, the results of this study demonstrated that 4-OI improved cognitive deficits in AD mice, confirming the therapeutic effect of 4-OI on AD.

Neuroprotective effects of cordycepin on MPTP-induced Parkinson's disease mice via suppressing PI3K/AKT/mTOR and MAPK-mediated neuroinflammation

Parkinson's disease (PD) is a prevalent progressive and multifactorial neurodegenerative disorder. Cordycepin is known to exhibit antitumor, anti-inflammatory, antioxidative stress, and neuroprotective effects; however, few studies have explored the neuroprotective mechanism of cordycepin in PD. Using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model, we investigated the impact of cordycepin on PD and its underlying molecular mechanisms. The findings indicated that cordycepin significantly mitigated MPTP-induced behavior disorder and neuroapoptosis, diminished the loss of dopaminergic neurons in the striatum-substantia nigra pathway, elevated striatal monoamine levels and its metabolites, and inhibited the polarization of microglia and the expression of pro-inflammatory factors. Subsequent proteomic and phosphoproteomic analyses revealed the involvement of the MAPK, mTOR, and PI3K/AKT signaling pathways in the protective mechanism of cordycepin. Cordycepin treatment inhibited the activation of the PI3K/AKT/mTOR signaling pathway and enhanced the expression of autophagy proteins in the striatum and substantia nigra. We also demonstrated the in vivo inhibition of the ERK/JNK signaling pathway by cordycepin treatment. In summary, our investigation reveals that cordycepin exerts neuroprotective effects against PD by promoting autophagy and suppressing neuroinflammation and neuronal apoptosis by inhibiting the PI3K/AKT/mTOR and ERK/JNK signaling pathways. This finding highlights the favorable characteristics of cordycepin in neuroprotection and provides novel molecular insights into the neuroprotective role of natural products in PD.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Targeting the key players of phenotypic plasticity in cancer cells by phytochemicals

Plasticity of phenotypic traits refers to an organism's ability to change in response to environmental stimuli. As a result, the response may alter an organism's physiological state, morphology, behavior, and phenotype. Phenotypic plasticity in cancer cells describes the considerable ability of cancer cells to transform phenotypes through non-genetic molecular signaling activities that promote therapy evasion and tumor metastasis via amplifying cancer heterogeneity. As a result of metastable phenotypic state transitions, cancer cells can tolerate chemotherapy or develop transient adaptive resistance. Therefore, new findings have paved the road in identifying factors and agents that inhibit or suppress phenotypic plasticity. It has also investigated novel multitargeted agents that may promise new effective strategies in cancer treatment. Despite the efficiency of conventional chemotherapeutic agents, drug toxicity, development of resistance, and high-cost limit their use in cancer therapy. Recent research has shown that small molecules derived from natural sources are capable of suppressing cancer by focusing on the plasticity of phenotypic responses. This systematic, comprehensive, and critical review analyzes the current state of knowledge regarding the ability of phytocompounds to target phenotypic plasticity at both preclinical and clinical levels. Current challenges/pitfalls, limitations, and future perspectives are also discussed.

J24335 exerts neuroprotective effects against 6-hydroxydopamine-induced lesions in PC12 cells and mice

Parkinson's disease is the second most prevalent age-related neurodegenerative disease and disrupts the lives of people aged >60 years. Meanwhile, single-target drugs becoming inapplicable as PD pathogenesis diversifies. Mitochondrial dysfunction and neurotoxicity have been shown to be relevant to the pathogenesis of PD. The novel synthetic compound J24335 (11-Hydroxy-1-(8-methoxy-5-(trifluoromethyl)quinolin-2-yl)undecan-1-one oxime), which has been researched similarly to J2326, has the potential to be a multi-targeted drug and alleviate these lesions. Therefore, we investigated the mechanism of action and potential neuroprotective function of J24335 against 6-OHDA-induced neurotoxicity in mice, and in PC12 cell models. The key target of action of J24335 was also screened. MTT assay, LDH assay, flow cytometry, RT-PCR, LC-MS, OCR and ECAR detection, and Western Blot analysis were performed to characterize the neuroprotective effects of J24335 on PC12 cells and its potential mechanism. Behavioral tests and immunohistochemistry were used to evaluate behavioral changes and brain lesions in mice. Moreover, bioinformatics was employed to assess the drug-likeness of J24335 and screen its potential targets. J24335 attenuated the degradation of mitochondrial membrane potential and enhanced glucose metabolism and mitochondrial biosynthesis to ameliorate 6-OHDA-induced mitochondrial dysfunction. Animal behavioral tests demonstrated that J24335 markedly improved motor function and loss of TH-positive neurons and dopaminergic nerve fibers, and contributed to an increase in the levels of dopamine and its metabolites in brain tissue. The activation of both the CREB/PGC-1α/NRF-1/TFAM and PKA/Akt/GSK-3β pathways was a major contributor to the neuroprotective effects of J24335. Furthermore, bioinformatics predictions revealed that J24335 is a low toxicity and highly BBB permeable compound targeting 8 key genes (SRC, EGFR, ERBB2, SYK, MAPK14, LYN, NTRK1 and PTPN1). Molecular docking suggested a strong and stable binding between J24335 and the 8 core targets. Taken together, our results indicated that J24335, as a multi-targeted neuroprotective agent with promising therapeutic potential for PD, could protect against 6-OHDA-induced neurotoxicity via two potential pathways in mice and PC12 cells.

Neuroprotective potentials of Lead phytochemicals against Alzheimer's disease with focus on oxidative stress-mediated signaling pathways: Pharmacokinetic challenges, target specificity, clinical trials and future perspectives

BACKGROUND

Alzheimer's diseases (AD) and dementia are among the highly prevalent neurological disorders characterized by deposition of beta amyloid (Aβ) plaques, dense deposits of highly phosphorylated tau proteins, insufficiency of acetylcholine (ACh) and imbalance in glutamatergic system. Patients typically experience cognitive, behavioral alterations and are unable to perform their routine activities. Evidence also suggests that inflammatory processes including excessive microglia activation, high expression of inflammatory cytokines and release of free radicals. Thus, targeting inflammatory pathways beside other targets might be the key factors to control- disease symptoms and progression.

PURPOSE

This review is aimed to highlight the mechanisms and pathways involved in the neuroprotective potentials of lead phytochemicals. Further to provide updates regarding challenges associated with their use and their progress into clinical trials as potential lead compounds.

METHODS

Most recent scientific literature on pre-clinical and clinical data published in quality journals especially on the lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin was collected using SciFinder, PubMed, Google Scholar, Web of Science, JSTOR, EBSCO, Scopus and other related web sources.

RESULTS

Literature review indicated that the drug discovery against AD is insufficient and only few drugs are clinically approved which have limited efficacy. Among the therapeutic options, natural products have got tremendous attraction owing to their molecular diversity, their safety and efficacy. Research suggest that natural products can delay the disease onset, reduce its progression and regenerate the damage via their anti-amyloid, anti-inflammatory and antioxidant potentials. These agents regulate the pathways involved in the release of neurotrophins which are implicated in neuronal survival and function. Highly potential lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin regulate neuroprotective signaling pathways implicated in neurotrophins-mediated activation of tropomyosin receptor kinase (Trk) and p75 neurotrophins receptor (p75NTR) family receptors.

CONCLUSIONS

Phytochemicals especially phenolic compounds were identified as highly potential molecules which ameliorate oxidative stress induced neurodegeneration, reduce Aβ load and inhibit vital enzymes. Yet their clinical efficacy and bioavailability are the major challenges which need further interventions for more effective therapeutic outcomes.

Mechanistic insights into the anti-depressant effect of curcumin based on network pharmacology and experimental validation

Curcumin (CUR) exhibits a definite curative effect in the treatment of depression. To identify potential antidepressant targets and mechanisms of action of CUR. This study used network pharmacology to explore the signaling pathways and CUR-related targets in depression. C57BL/6 J mice (male,12-14 weeks old) were randomly divided into four groups (n = 8): saline-treated (control mice), lipopolysaccharide (LPS, 2 mg/kg/day, intraperitoneally), LPS + CUR (50 mg/kg/day, intragastrically), and LPS + CUR + LY294002 (7.5 mg/kg/day, intraperitoneally). After 1 week, behavioral tests were performed. Then, neuronal damage in the prefrontal cortex of mice was evaluated by hematoxylin-eosin (HE) staining. We uncovered the main active mechanism of CUR against depression using Western blotting and enzyme-linked immunosorbent assay (ELISA). Gene set enrichment analysis (GSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways showed that the most significantly enriched pathway in CUR against depression was the PI3K-Akt pathway. Moreover, 52 targets were significantly correlated with the PI3K-Akt signaling pathway and CUR-related targets. In addition, among the top 50 targets ranked by degree in the protein-protein interaction (PPI) network, there were 23 targets involved in the 52 intersection targets. Administration of LPS alone extended immobility time in the open field test (OFT) and tail suspension test (TST) and decreased sucrose consumption in the sucrose preference test (SPT). Pretreatment with CUR relieved LPS-induced changes in the behavioral tests, activity of the PI3K-Akt signaling pathway, neuronal damage in the prefrontal cortex (PFC), and inflammatory response. Moreover, inhibition of the PI3K-Akt signaling pathway by LY294002 blocked the therapeutic effects of CUR. Our study indicates that CUR may be an effective antidepressant agent in an LPS-induced mouse model, partly because of its anti-inflammatory action through the PI3K-Akt signaling pathway.

Rosmarinic acid alleviate CORT-induced depressive-like behavior by promoting neurogenesis and regulating BDNF/TrkB/PI3K signaling axis

Rosmarinic acid (RA), a natural phenolic acid compound with a variety of bioactive properties. However, the antidepressant activity and mechanism of RA remain unclear. The aim of this study is to investigate the effects and potential mechanisms of RA on chronic CORT injection induced depression-like behavior in mice. Male C57BL/6 J mice were intraperitoneally injected with CORT (10 mg/kg) and were orally given RA daily (10 or 20 mg/kg) for 21 consecutive days. In vitro, the HT22 cells were exposed to CORT (200 μM) with RA (12.5, 25 or 50 μM) and LY294002 (a PI3K inhibitor) or ANA-12 (a TrkB inhibitor) treatment. The depression-like behavior and various neurobiological changes in the mice and cell injury and levels of target proteins in vitro were subsequently assessed. Here, RA treatment decreased the expression of p-GR/GR, HSP90, FKBP51, SGK-1 in mice hippocampi. Besides, RA increased the average optical density of Nissl bodies and number of dendritic spines in CA3 region, and enhanced Brdu and DCX expression and synaptic transduction in DG region, as well as up-regulated both the BDNF/TrkB/CREB and PI3K/Akt/mTOR signaling. Moreover, RA reduced structural damage and apoptosis in HT22 cells, increased the differentiation and maturation of them. More importantly, LY294002, but not ANA-12, reversed the effect of RA on GR nuclear translocation. Taken together, RA exerted antidepressant activities by modulating the hippocampal glucocorticoid signaling and hippocampal neurogenesis, which related to the BDNF/TrkB/PI3K signaling axis regulating GR nuclear translocation, provide evidence for the application of RA as a candidate for depression.

Role of BDNF Signaling in the Neuroprotective and Memory-enhancing Effects of Flavonoids in Alzheimer's Disease

BACKGROUND

Foods rich in flavonoids are associated with a reduced risk of various chronic diseases, including Alzheimer's disease (AD). In fact, growing evidence suggests that consuming flavonoid- rich foods can beneficially affect normal cognitive function. Animal models have shown that many flavonoids prevent the development of AD-like pathology and improve cognitive deficits.

OBJECTIVE

Identifying the molecular causes underlying the memory-enhancing effect of flavonoid-rich foods makes it possible to provide the best diet to prevent cognitive decline associated with aging and Alzheimer's disease. Based on the most recent scientific literature, this review article critically examines the therapeutic role of dietary flavonoids in ameliorating and preventing the progression of AD and enhancement of memory with a focus on the role of the BDNF signaling pathway.

METHODS

The databases of PubMed, Web of Science, Google Scholar, and Scopus were searched up to March 2023 and limited to English language. Search strategies were using the following keywords in titles and abstracts: (Flavonoid-rich foods OR Flavonoids OR Polyphenols); AND (Brain-Derived Neurotrophic Factor OR BDNF OR CREB OR) AND (Alzheimer's disease OR memory OR cognition OR).

RESULTS

Flavonoid-rich foods including green tea, berries, curcumin and pomegranate exert their beneficial effects on memory decline associated with aging and Alzheimer's disease mostly through the direct interaction with BDNF signaling pathway.

CONCLUSION

The neuroprotective effects of flavonoid-rich foods through the CREB-BDNF mechanism have the potential to prevent or limit memory decline due to aging and Alzheimer's disease, so their consumption throughout life may prevent age-related cognitive impairment.

Advances of phytotherapy in ischemic stroke targeting PI3K/Akt signaling

The pathogenesis of ischemic stroke is complex, and PI3K/Akt signaling is considered to play a crucial role in it. The PI3K/Akt pathway regulates inflammation, oxidative stress, apoptosis, autophagy, and vascular endothelial homeostasis after cerebral ischemia; therefore, drug research targeting the PI3K/Akt pathway has become the focus of scientists. In this review, we analyzed the research reports of antiischemic stroke drugs targeting the PI3K/Akt pathway in the past two decades. Because of the rich sources of natural products, increasing studies have explored the value of natural compounds, including Flavonoids, Quinones, Alkaloids, Phenylpropanoids, Phenols, Saponins, and Terpenoids, in alleviating neurological impairment and achieved satisfactory results. Herbal extracts and medicinal formulas have been applied in the treatment of ischemic stroke for thousands of years in East Asian countries. These precious clinical experiences provide a new avenue for research of antiischemic stroke drugs. Finally, we summarize and discuss the characteristics and shortcomings of the current research and put forward prospects for further in-depth exploration.

Implicative role of Cytokines in Neuroinflammation mediated AD and associated signaling pathways: Current Progress in molecular signaling and therapeutics

Alzheimer's Disease (AD) is one of the most devastating age-related disorder causing significant social and economic burden worldwide. It affects the cognitive and social behavior of individuals and characterized by accumulation of Aβ, phosphorylated tau and cytokines formation. The synthesis and release of cytokines are regulated by specific groups of immune and non-immune cells in response to microglia or astrocyte activation through multiple pathways. Physiologically, microglia assert an anti-inflammatory, quiescent state with minimal cytokine expression and little phagocytic activity in motion to carry out their housekeeping role to eliminate pathogens, aggregated Aβ and tau protein. However, they develop a phagocytic nature and overexpress cytokine gene modules in response to certain stimuli in AD. Microglia and astrocytes upon chronic activation release an enormous amount of inflammatory cytokines due to interaction with formed Aβ and neurofibrillary tangle. Gut microbiota dysbiosis also stimulates the release of inflammatory cytokines contributing to AD pathogenesis. In addition, the dysregulation of few signaling pathways significantly influences the development of disease, and the pace of advancement also rises with age. This review sheds light on multiple pathways results into neuroinflammation triggered by activated cytokines worsening AD pathology and making it an appropriate target for AD treatment. This review also included drugs targeting different neuroinflammation pathways under clinical and preclinical studies that are found to be effective in attenuating the disease pathology.

Network pharmacology‒based analysis of marine cyanobacteria derived bioactive compounds for application to Alzheimer's disease

In recent years, the Alzheimer's disease (AD) epidemic has become one of the largest global healthcare crises. Besides, the available systemic therapies for AD are still inadequate. Due to the insufficient therapeutic options, new treatment strategies are urgently needed to achieve a satisfactory therapeutic effect. Marine bio-resources have been accepted as one of the most economically viable and sustainable sources with potential applications for drug discovery and development. In this study, a marine cyanobacteria-Synechococcus sp. XM-24 was selected as the object of research, to systematically investigate its therapeutic potential mechanisms for AD. The major active compounds derived from the Synechococcus sp. biomass were identified via pyrolysis-gas chromatography-mass spectrometry (GC-MS), and 22 compounds were identified in this strain. The most abundant chemical compounds was (E)-octadec-11-enoic acid, with the peak area of 30.6%. Follow by tridecanoic acid, 12-methyl- and hexadecanoic acid, with a peak area of 23.26% and 18.23%, respectively. GC-MS analysis also identified indolizine, isoquinoline, 3,4-dihydro- and Phthalazine, 1-methyl-, as well as alkene and alkane from the strain. After the chemical toxicity test, 10 compounds were finally collected to do the further analysis. Then, network pharmacology and molecular docking were adopted to systematically study the potential anti-AD mechanism of these compounds. Based on the analysis, the 10 Synechococcus-derived active compounds could interact with 128 related anti-AD targets. Among them, epidermal growth factor receptor (EGFR), vascular endothelial growth factor A (VEGFA) and mitogen-activated protein kinase 3 (MAPK3) were the major targets. Furthermore, the compounds N-capric acid isopropyl ester, (E)-octadec-11-enoic acid, and 2H-Pyran-2,4(3H)-dione, dihydro-6-methyl- obtained higher degrees in the compounds-intersection targets network analysis, indicating these compounds may play more important role in the process of anti-AD. In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that these active compounds exert the anti-AD effects mainly through PI3K-Akt signaling pathway, neuroactive ligand-receptor interaction and ras signaling pathway. Our study identified Synechococcus-derived bioactive compounds have the potential for application to AD by targeting multiple targets and related pathways, which will provide a foundation for future research on applications of marine cyanobacteria in the functional drug industry.

Oxidative stress as a key event in 2,6-dichloro-1,4-benzoquinone-induced neurodevelopmental toxicity

2,6-dichloro-1,4-benzoquinone (DCBQ) has been identified as an emerging disinfection byproducts (DBPs) in drinking water and has the potential to induce neurodevelopmental toxicity. However, there is rarely a comprehensive toxicological evaluation of the neurodevelopmental toxicity of DCBQ. Here, neural differentiating SH-SY5Y cells were used as an in vitro model. Our results have found that DCBQ has decreased cell viability and neural differentiation, generated higher level of reactive oxygen species (ROS), increased the percentage of apoptosis and lowered the level of mitochondrial membrane potential, suggesting the neurodevelopmental toxicity of DCBQ. In addition, antioxidant N-acetyl-L-cysteine (NAC) could significantly attenuate these DCBQ-induced neurotoxic effects, supporting our hypothesis that the neurodevelopmental toxicity may be related with oxidative stress induced by DCBQ. We further demonstrated that DCBQ-induced neurodevelopmental toxicity could promote the mitochondrial apoptosis pathway and inhibit the prosurvival PI3K/AKT/mTOR pathway through inducing ROS, which ultimately inhibited cell proliferation and induced apoptosis in neural differentiating SH-SY5Y cells. These findings have provided novel insights into the risk of neurodevelopmental toxic effects associated with DCBQ exposure, emphasizing the importance of assessing the potential neurodevelopmental toxicity of DBPs.

11-Ethoxyviburtinal improves chronic restraint stress-induced anxiety-like behaviors in gender-specific mice via PI3K/Akt and E2 /ERβ signaling pathways

Anxiety disorder is a chronic and disabling psychiatric disorder that is more prevalent in females than in males. 11-Ethoxyviburtinal is an iridoid extracted from Valeriana jatamansi Jones, which has anxiolytic potential. The aim of the present work was to study the anxiolytic efficacy and mechanism of 11-ethoxyviburtinal in gender-specific mice. We first evaluated the anxiolytic-like efficacy of 11-ethoxyviburtinal in chronic restraint stress (CRS) mice of different sexes through behavioral experiments and biochemical indexes. In addition, network pharmacology and molecular docking were used to predict potential targets and important pathways for the treatment of anxiety disorder with 11-ethoxyviburtinal. Finally, the influence of 11-ethoxyviburtinal on phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, estrogen receptor β (ERβ) expression, and anxiety-like behavior in mice was verified by western blotting, immunohistochemistry staining, antagonist intervention methods, and behavioral experiments. 11-ethoxyviburtinal alleviated the anxiety-like behaviors induced by CRS and inhibited neurotransmitter dysregulation and HPA axis hyperactivity. It inhibited the abnormal activation of the PI3K/Akt signaling pathway, modulated estrogen production, and promoted ERβ expression in mice. In addition, the female mice may be more sensitive to the pharmacological effects of 11-ethoxyviburtinal. 11-ethoxyviburtinal may exert its anxiolytic-like effects through PI3K/Akt and E2/ERβ signaling pathways. Meanwhile, by comparing the male and female mice, gender differences may affect the therapy and development of anxiety disorder.

BDNF alleviates Parkinson's disease by promoting STAT3 phosphorylation and regulating neuronal autophagy

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the gradual death of dopaminergic neurons. Brain-derived neurotrophic factor (BDNF) and its receptors are widely distributed throughout the central nervous system, which can promote the survival and growth of neurons and protect neurons. This study revealed that BDNF promotes STAT3 phosphorylation and regulates autophagy in neurons. The PD mouse model was established by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Moreover, SH-SY5Y cells were treated with 1-methyl-4-phenyl-pyridinium (MPP+) to establish a PD cell model. The level of BDNF was low in PD model mice and SH-SY5Y cells treated with MPP+. BDNF enhanced the levels of p-TrkB, P-STAT3, PINK1, and DJ-1. BDNF promoted autophagy, inhibited the level of p-α-syn (Ser129) and enhanced cell proliferation. The autophagy inhibitor 3-Methyladenine (3-methyladenine, 3-MA) reversed the protective effects of BDNF on neurons. BiFC assay results showed that there was a direct physical interaction between BDNF and STAT3, and coimmunoprecipitation experiments indicated an interaction between STAT3 and PI3K. The PI3K agonist Recilisib activated the PI3K/AKT/mTOR pathway, promoted autophagy, and alleviated neuronal cell damage. BDNF alleviates PD pathology by promoting STAT3 phosphorylation and regulating neuronal autophagy in SH-SY5Y cells and cultured primary neurons. Finally, BDNF has neuroprotective effects on PD model mice.

Current advances in nanoformulations of therapeutic agents targeting tumor microenvironment to overcome drug resistance

The tumor microenvironment (TME) plays a pivotal role in cancer development and progression. In this line, revealing the precise mechanisms of the TME and associated signaling pathways of tumor resistance could pave the road for cancer prevention and efficient treatment. The use of nanomedicine could be a step forward in overcoming the barriers in tumor-targeted therapy. Novel delivery systems benefit from enhanced permeability and retention effect, decreasing tumor resistance, reducing tumor hypoxia, and targeting tumor-associated factors, including immune cells, endothelial cells, and fibroblasts. Emerging evidence also indicates the engagement of multiple dysregulated mediators in the TME, such as matrix metalloproteinase, vascular endothelial growth factor, cytokines/chemokines, Wnt/β-catenin, Notch, Hedgehog, and related inflammatory and apoptotic pathways. Hence, investigating novel multitargeted agents using a novel delivery system could be a promising strategy for regulating TME and drug resistance. In recent years, small molecules from natural sources have shown favorable anticancer responses by targeting TME components. Nanoformulations of natural compounds are promising therapeutic agents in simultaneously targeting multiple dysregulated factors and mediators of TME, reducing tumor resistance mechanisms, overcoming interstitial fluid pressure and pericyte coverage, and involvement of basement membrane. The novel nanoformulations employ a vascular normalization strategy, stromal/matrix normalization, and stress alleviation mechanisms to exert higher efficacy and lower side effects. Accordingly, the nanoformulations of anticancer monoclonal antibodies and conventional chemotherapeutic agents also improved their efficacy and lessened the pharmacokinetic limitations. Additionally, the coadministration of nanoformulations of natural compounds along with conventional chemotherapeutic agents, monoclonal antibodies, and nanomedicine-based radiotherapy exhibits encouraging results. This critical review evaluates the current body of knowledge in targeting TME components by nanoformulation-based delivery systems of natural small molecules, monoclonal antibodies, conventional chemotherapeutic agents, and combination therapies in both preclinical and clinical settings. Current challenges, pitfalls, limitations, and future perspectives are also discussed.

Therapeutic targeting of Ras/Raf/MAPK pathway by natural products: A systematic and mechanistic approach for neurodegeneration

BACKGROUND

Multiple dysregulated pathways are behind the pathogenesis of neurodegenerative diseases (NDDs); however, the crucial targets are still unknown. Oxidative stress, apoptosis, autophagy, and inflammation are the most dominant pathways that strongly influence neurodegeneration. In this way, targeting the Ras/Raf/mitogen-activated protein kinases (MAPKs) pathway appears to be a developing strategy for combating NDDs like Parkinson's disease, Alzheimer's disease, stroke, aging, and other NDDs. Accordingly, plant secondary metabolites have shown promising potentials for the simultaneous modulation of the Ras/Raf/MAPKs pathway and play an essential role in NDDs. MAPKs include p38 MAPK, extracellular signal-regulated kinase 1/2 (ERK 1/2), and c-Jun N-terminal kinase (JNK), which are important molecular players in neurodegeneration. Ras/Raf, which is located the upstream of MAPK pathway influences the initiation and progression of neurodegeneration and is regulated by natural products.

PURPOSE

Thus, the present study aimed to investigate the neuroprotective roles of plant- and marine-derived secondary metabolites against several NDDs through the modulation of the Ras/Raf/MAPK signaling pathway.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was performed to highlight the modulatory roles of natural products on the Ras/Raf/MAPK signaling pathway in NDDs, according to the PRISMA guideline, using scholarly electronic databases, including PubMed, Scopus, and Web of Sciences. Associated reference lists were also searched for the literature review.

RESULTS

From a total of 1495 results, finally 107 articles were included in the present study. The results show that several natural compounds such as alkaloid, phenolic, terpenoids, and nanoformulation were shown to have modulatory effects on the Ras/Raf/MAPKs pathway.

CONCLUSION

Natural products are promising multi-targeted agents with on NDDs through Ras/Raf/MAPKs pathway. Nevertheless, additional and complementary studies are necessary to check its efficacy and potential side effects.

Analysis of gene expression profiles and experimental validations of a rat chronic cervical cord compression model

Cervical spondylotic myelopathy (CSM) is a severe non-traumatic spinal cord injury (SCI) wherein the spinal canal and cervical cord are compressed due to the degeneration of cervical tissues. To explore the mechanism of CSM, the ideal model of chronic cervical cord compression in rats was constructed by embedding a polyvinyl alcohol polyacrylamide hydrogel in lamina space. Then, the RNA sequencing technology was used to screen the differentially expressed genes (DEGs) and enriched pathways among intact and compressed spinal cords. A total of 444 DEGs were filtered out based on the value of log₂(Compression/Sham); these were associated with IL-17, PI3K-AKT, TGF-β, and Hippo signaling pathways according to the GSEA, KEGG, and GO analyses. Transmission electron microscopy indicated the changes in mitochondrial morphology. Western blot and immunofluorescent staining revealed neuronal apoptosis, astrogliosis and microglial neuroinflammation in the lesion area. Specifically, the expression of apoptotic indicators, such as Bax and cleaved caspase-3, and inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, were upregulated. The activation of IL-17 signaling pathways was observed in microglia instead of neurons or astrocytes, the activation of TGF-β and inhibition of Hippo signaling pathways were detected in astrocytes instead of neurons or microglia, and the inhibition of PI3K-AKT signaling pathway was discovered in neurons rather than microglia of astrocytes in the lesion area. In conclusion, this study indicated that neuronal apoptosis was accompanied by inhibiting of the PI3K-AKT pathway. Then, the activation of microglia IL-17 pathway and NLRP3 inflammasome effectuated the neuroinflammation, and astrogliosis was ascribed to the activation of TGF-β and the inhibition of the Hippo pathway in the chronic cervical cord of compression. Therefore, therapeutic methods targeting these pathways in nerve cells could be promising CSM treatments.

Recent advances to Neuroprotection: repurposing drugs against neuroinflammatory disorders

Cell death is a natural mechanism for biological clearance for the maintenance of homeostasis in a dynamic microenvironment of the central nervous system. Stress and various factors can lead to imbalance between cellular genesis and cell death leading to dysfunctionality and a number of neuropathological disorders. Drug repurposing can help bypass development time and cost. A complete understanding of drug actions and neuroinflammatory pathways can lead to effective control of neurodegenerative disorders. This review covers recent advances in various neuroinflammatory pathways understanding, biomarkers, and drug repurposing for neuroprotection.

Deletion of PTEN in microglia ameliorates chronic neuroinflammation following repetitive mTBI

Traumatic brain injury is a leading cause of morbidity and mortality in adults and children in developed nations. Following the primary injury, microglia, the resident innate immune cells of the CNS, initiate several inflammatory signaling cascades and pathophysiological responses that may persist chronically; chronic neuroinflammation following TBI has been closely linked to the development of neurodegeneration and neurological dysfunction. Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that have been shown to regulate several key mechanisms in the inflammatory response to TBI. Increasing evidence has shown that the modulation of the PI3K/AKT signaling pathway has the potential to influence the cellular response to inflammatory stimuli. However, directly targeting PI3K signaling poses several challenges due to its regulatory role in several cell survival pathways. We have previously identified that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN), the major negative regulator of PI3K/AKT signaling, is dysregulated following exposure to repetitive mild traumatic brain injury (r-mTBI). Moreover, this dysregulated PI3K/AKT signaling was correlated with chronic microglial-mediated neuroinflammation. Therefore, we interrogated microglial-specific PTEN as a therapeutic target in TBI by generating a microglial-specific, Tamoxifen inducible conditional PTEN knockout model using a CX3CR1 Cre recombinase mouse line PTEN^fl/fl/CX3CR1^+/CreERT2 (mcg-PTEN^cKO), and exposed them to our 20-hit r-mTBI paradigm. Animals were treated with tamoxifen at 76 days post-last injury, and the effects of microglia PTEN deletion on immune-inflammatory responses were assessed at 90-days post last injury. We observed that the deletion of microglial PTEN ameliorated the proinflammatory response to repetitive brain trauma, not only reducing chronic microglial activation and proinflammatory cytokine production but also rescuing TBI-induced reactive astrogliosis, demonstrating that these effects extended beyond microglia alone. Additionally, we observed that the pharmacological inhibition of PTEN with BpV(HOpic) ameliorated the LPS-induced activation of microglial NFκB signaling in vitro. Together, these data provide support for the role of PTEN as a regulator of chronic neuroinflammation following repetitive mild TBI.

TMAO promotes dementia progression by mediating the PI3K/Akt/mTOR pathway

BACKGROUND

Dementia poses a serious threat to the daily and social abilities of patients, and trimethylamine-N-oxide (TMAO) is a metabolite of the gut microbiota involved in regulating the inflammatory response. However, the role of TMAO in dementia needs further investigation. This study aimed to investigate the effects and possible mechanisms of TMAO on dementia, which may provide ideas for the treatment of dementia.

MATERIALS AND METHODS

Dementia mice were induced by D-galactose + AlCl₃, and the changes in learning memory capacity, histopathology, inflammatory factors, and PI3K/Akt/mTOR in mice treated with TMAO were analyzed to determine the mechanism of TMAO action on dementia. In addition, the effect of TMAO+PI3K inhibitor treatment on mice was also analyzed to further determine the mechanism of TMAO effect on dementia.

RESULTS

The results revealed that the dementia group had significantly higher TMAO levels and a significant hippocampal injury and inflammatory response. TMAO treatment promoted hippocampal injury and promoted the level of inflammatory cytokines. Further study of PI3K/Akt/mTOR signaling pathway showed that the expression of p-PI3K, p-Akt, and p-mTOR was significantly increased in the dementia group, and it was more obvious after TMAO treatment. And hippocampal injury, inflammatory response, and increase of p-PI3K, p-Akt, p-mTOR were reversed by TMAO+PI3K inhibitor.

CONCLUSIONS

This study determined that TMAO promotes dementia through the PI3K/Akt/mTOR signaling pathway, suggesting that TMAO may be a potential target for dementia.

The pivotal role of JAK/STAT and IRS/PI3K signaling pathways in neurodegenerative diseases: Mechanistic approaches to polyphenols and alkaloids

BACKGROUND

Neurodegenerative diseases (NDDs) are characterized by progressive neuronal dysfunctionality which results in disability and human life-threatening events. In recent decades, NDDs are on the rise. Besides, conventional drugs have not shown potential effectiveness to attenuate the complications of NDDs. So, exploring novel therapeutic agents is an urgent need to combat such disorders. Accordingly, growing evidence indicates that polyphenols and alkaloids are promising natural candidates, possessing several beneficial pharmacological effects against diseases. Considering the complex pathophysiological mechanisms behind NDDs, Janus kinase (JAK), insulin receptor substrate (IRS), phosphoinositide 3-kinase (PI3K), and signal transducer and activator of transcription (STAT) seem to play critical roles during neurodegeneration/neuroregeneration. In this line, modulation of the JAK/STAT and IRS/PI3K signaling pathways and their interconnected mediators by polyphenols/alkaloids could play pivotal roles in combating NDDs, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), stroke, aging, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), depression and other neurological disorders.

PURPOSE

Thus, the present study aimed to investigate the neuroprotective roles of polyphenols/alkaloids as multi-target natural products against NDDs which are critically passing through the modulation of the JAK/STAT and IRS/PI3K signaling pathways.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was performed to highlight the modulatory roles of polyphenols and alkaloids on the JAK/STAT and IRS/PI3K signaling pathways in NDDs, according to the PRISMA guideline, using scholarly electronic databases, including Scopus, PubMed, ScienceDirect, and associated reference lists.

RESULTS

In the present study 141 articles were included from a total of 1267 results. The results showed that phenolic compounds such as curcumin, epigallocatechin-3-gallate, and quercetin, and alkaloids such as berberine could be introduced as new strategies in combating NDDs through JAK/STAT and IRS/PI3K signaling pathways. This is the first systematic review that reveals the correlation between the JAK/STAT and IRS/PI3K axis which is targeted by phytochemicals in NDDs. Hence, this review highlighted promising insights into the neuroprotective potential of polyphenols and alkaloids through the JAK/STAT and IRS/PI3K signaling pathway and interconnected mediators toward neuroprotection.

CONCLUSION

Amongst natural products, phenolic compounds and alkaloids are multi-targeting agents with the most antioxidants and anti-inflammatory effects possessing the potential of combating NDDs with high efficacy and lower toxicity. However, additional reports are needed to prove the efficacy and possible side effects of natural products.

Effects of saponins from Chinese herbal medicines on signal transduction pathways in cancer: A review

Cancer poses a serious threat to human health, and the search for safe and effective drugs for its treatment has aroused interest and become a long-term goal. Traditional Chinese herbal medicine (TCM), an ancient science with unique anti-cancer advantages, has achieved outstanding results in long-term clinical practice. Accumulating evidence shows that saponins are key bioactive components in TCM and have great research and development applications for their significant role in the treatment of cancer. Saponins are a class of glycosides comprising nonpolar triterpenes or sterols attached to hydrophilic oligosaccharide groups that exert antitumor effects by targeting the NF-κB, PI3Ks-Akt-mTOR, MAPK, Wnt-β-catenin, JAK-STAT3, APMK, p53, and EGFR signaling pathways. Presently, few advances have been made in physiological and pathological studies on the effect of saponins on signal transduction pathways involved in cancer treatment. This paper reviews the phytochemistry and extraction methods of saponins of TCM and their effects on signal transduction pathways in cancer. It aims to provide theoretical support for in-depth studies on the anticancer effects of saponins.

The Exosome-Mediated PI3K/Akt/mTOR Signaling Pathway in Neurological Diseases

As major public health concerns associated with a rapidly growing aging population, neurodegenerative diseases (NDDs) and neurological diseases are important causes of disability and mortality. Neurological diseases affect millions of people worldwide. Recent studies have indicated that apoptosis, inflammation, and oxidative stress are the main players of NDDs and have critical roles in neurodegenerative processes. During the aforementioned inflammatory/apoptotic/oxidative stress procedures, the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway plays a crucial role. Considering the functional and structural aspects of the blood-brain barrier, drug delivery to the central nervous system is relatively challenging. Exosomes are nanoscale membrane-bound carriers that can be secreted by cells and carry several cargoes, including proteins, nucleic acids, lipids, and metabolites. Exosomes significantly take part in the intercellular communications due to their specific features including low immunogenicity, flexibility, and great tissue/cell penetration capabilities. Due to their ability to cross the blood-brain barrier, these nano-sized structures have been introduced as proper vehicles for central nervous system drug delivery by multiple studies. In the present systematic review, we highlight the potential therapeutic effects of exosomes in the context of NDDs and neurological diseases by targeting the PI3K/Akt/mTOR signaling pathway.

Inhibition of PI3K/Akt/mTOR signaling by NDRG2 contributes to neuronal apoptosis and autophagy in ischemic stroke

BACKGROUND

Astrocytic N-myc downstream-regulated gene 2 (NDRG2), a differentiation- and stress-associated molecule, has been involved in the cause of ischemic stroke (IS). However, its downstream effector in IS remains unclear. This study aimed to characterize expression of NDRG2 in IS patients and rats and to investigate the underlying mechanism.

METHODS

The protein expression of NDRG2 and mammalian target of the rapamycin (mTOR) and the extent of mTOR phosphorylation in plasma of IS patients were detected by ELISA. An oxygen-glucose deprivation model was established in mouse neuronal cells CATH.a, followed by cell counting kit-8, flow cytometry, TUNEL, and western blot assays to examine cell viability, apoptosis and autophagy. Finally, the effect of NDRG2-mediated phosphatidylinositol 3-kinase/protein kinase-B/mTOR (PI3K/AKT/mTOR) pathway on neuronal apoptosis and autophagy was verified in rats treated with middle cerebral artery occlusion.

RESULTS

NDRG2 was highly expressed in the plasma of IS patients, while the extent of mTOR phosphorylation was reduced in IS patients. NDRG2 blocked the PI3K/Akt/mTOR signaling through dephosphorylation. Depletion of NDRG2 suppressed apoptosis and autophagy in CATH.a cells, which was reversed by a dual inhibitor of PI3K and mTOR, BEZ235. In vivo experiments confirmed that NDRG2 promoted neuronal apoptosis and autophagy by dephosphorylating and blocking the PI3K/Akt/mTOR signaling.

CONCLUSION

The present study has shown that NDRG2 impairs the PI3K/Akt/mTOR pathway via dephosphorylation to promote neuronal apoptosis and autophagy in IS. These findings provide potential targets for future clinical therapies for IS.