Berberine protects against 6-OHDA-induced neurotoxicity in PC12 cells and zebrafish through hormetic mechanisms involving PI3K/AKT/Bcl-2 and Nrf2/HO-1 pathways

Pharmacodynamical research of extracts and compounds in traditional Chinese medicines for Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease (AD). Currently, there is no cure for PD, and medications can only control the progression of the disease. Various experimental studies have shown the significant efficacy of TCM in treating PD, and combination with western medicine can enhance the effects and reduce toxicity. Thus, exploring effective anti-PD compounds from TCM has become a popular research fields. This review summarizes commonly used TCM extracts and natural products for the treatment of PD, both domestically and internationally. Furthermore, it delves into various mechanisms of TCM in treating PD, such as anti-oxidative stress, anti-inflammatory, anti-apoptotic, improve mitochondrial dysfunction, inhibits α-synuclein (α-Syn) misfolding and aggregation, regulating neurotransmitters, regulates intestinal flora, enhances immunity, and so on. The results reveal that most TCMs exert their neuroprotective effects through anti-inflammatory and anti-oxidative stress actions, thereby slowing down the progression of the disease. These TCM may hold the key to improving PD therapy and have tremendous potential to be developed as novel anti-PD drugs.

Berberine inhibits SGIV replication by suppressing inflammatory response and oxidative stress

Singapore grouper iridovirus (SGIV) is one of the major infectious diseases responsible for high mortality and huge economic losses in the grouper aquaculture industry. Berberine (BBR), a naturally occurring plant alkaloid, is a phytochemical having a variety of biological properties, such as antiviral, antioxidant, and anti-inflammatory effects. In this work, we used an in vitro model based on Western blot, ROS fluorescence probe, and real-time quantitative PCR (qRT-PCR) to examine the antiviral qualities of BBR against SGIV. The outcomes demonstrated that varying BBR concentrations could significantly inhibit the replication of SGIV. In addition, BBR greatly inhibited the production of genes associated with pro-inflammatory cytokines in SGIV-infected or SGIV-uninfected GS cells based on qRT-PCR data. Subsequent investigations demonstrated that BBR suppressed the expression of the promoter activity of NF-κB and NF-κB-p65 protein. Additionally, BBR reduced the phosphorylation of ERK 1/2, JNK, and p38. Furthermore, BBR also inhibits SGIV-induced ROS production by upregulating the expression of antioxidant-related genes. In conclusion, BBR is a viable therapy option for SGIV infection due to its antiviral properties.

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.

18Beta-Glycyrrhetinic Acid Attenuates H2O2-Induced Oxidative Damage and Apoptosis in Intestinal Epithelial Cells via Activating the PI3K/Akt Signaling Pathway

Oxidative stress causes gut dysfunction and is a contributing factor in several intestinal disorders. Intestinal epithelial cell survival is essential for maintaining human and animal health under oxidative stress. 18beta-Glycyrrhetinic acid (GA) is known to have multiple beneficial effects, including antioxidant activity; however, the underlying molecular mechanisms have not been well established. Thus, the present study evaluated the therapeutic effects of GA on H2O2-induced oxidative stress in intestinal porcine epithelial cells. The results showed that pretreatment with GA (100 nM for 16 h) significantly increased the levels of several antioxidant enzymes and reduced corresponding intracellular levels of reactive oxidative species and malondialdehyde. GA inhibited cell apoptosis via activating the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway, as confirmed by RNA sequencing. Further analyses demonstrated that GA upregulated the phosphorylation levels of PI3K and Akt and the protein level of B cell lymphoma 2, whereas it downregulated Cytochrome c and tumor suppressor protein p53 levels. Moreover, molecular docking analysis predicted the binding of GA to Vasoactive intestinal peptide receptor 1, a primary membrane receptor, to activate the PI3K/Akt signaling pathway. Collectively, these results revealed that GA protected against H2O2-induced oxidative damage and cell apoptosis via activating the PI3K/Akt signaling pathway, suggesting the potential therapeutic use of GA to alleviate oxidative stress in humans/animals.

The therapeutic effects of berberine for gastrointestinal cancers

Cancer is one of the most serious human health issues. Drug therapy is the major common way to treat cancer. There is a growing interest in using natural compounds to overcome drug resistance, adverse reactions, and target specificity of certain types of drugs that may affect several targets with fewer side effects and be beneficial against various types of cancer. In this regard, the use of herbal medicines alone or in combination with the main anticancer drugs is commonly available. Berberine (BBR), a nature-driven phytochemical component, is a well-known nutraceutical due to its wide variety of pharmacological activities, including antioxidant, anti-inflammatory, antibacterial, antifungal, antiparasitic, antidiabetic, antihypertensive, and hypolipidemic. In addition, BBR exerts anticancer activities. In present article, we summarized the information available on the therapeutic effects of BBR and its mechanisms on five types of the most prevalent gastrointestinal cancers, including esophageal, gastric, colorectal, hepatocarcinoma, and pancreatic cancers.

Interpreting the chemical changes and therapeutic effect of Coptidis Rhizoma against ulcerative colitis before and after processing based on mathematical statistics and network pharmacology

INTRODUCTION

Coptidis Rhizoma (CR) is one of the most frequently used herbs to treat ulcerative colitis (UC) and is often processed before usage. However, the composition changes and therapeutic effects of CR before and after processing in the treatment of UC are still unclear.

OBJECTIVE

The purpose of the study is to explore the chemical components and therapeutic effects of crude and processed CR.

MATERIAL AND METHODS

CR was processed according to the 2020 version of the Chinese Pharmacopoeia. The liquid chromatography-mass spectrometry (LC-MS) and multivariate statistical analysis were used to screen the different compounds before and after processing. The network pharmacological prediction was carried out. The mechanism and therapeutic effects between crude and processed CR were verified by using dextran sulphate sodium-induced UC mice assay.

RESULTS

Ten compounds distinguish crude and processed CR based on multivariate statistical analysis. Network pharmacology predicts that the 10 compounds mainly play a role through TNF-α and IL-6 targets and PI3K/Akt and HIF-1 signalling pathways, and these results are verified by molecular biology experiments. For IL-6, IL-10 and TNF-α inflammatory factors, CR is not effective, while CR stir-fried with Evodiae Fructus (CRFE) and ginger juice (CRGJ) are. For PI3K/p-Akt, Cleaved caspase3, NF- κBp65 and HIF-1α signalling pathways, CR has therapeutic effects, while CRFE and CRGJ are significant.

CONCLUSION

Overall, CRFE and CRGJ show better effects in treating UC. The chemical changes of processing and the efficacy of processed CR are correlated, which provides a scientific basis for the clinical use of crude and processed CR.

Role of Natural Compounds Modulating Heme Catabolic Pathway in Gut, Liver, Cardiovascular, and Brain Diseases

The crucial physiological process of heme breakdown yields biliverdin (BV) and bilirubin (BR) as byproducts. BV, BR, and the enzymes involved in their production (the "yellow players-YP") are increasingly documented as endogenous modulators of human health. Mildly elevated serum bilirubin concentration has been correlated with a reduced risk of multiple chronic pro-oxidant and pro-inflammatory diseases, especially in the elderly. BR and BV per se have been demonstrated to protect against neurodegenerative diseases, in which heme oxygenase (HMOX), the main enzyme in the production of pigments, is almost always altered. HMOX upregulation has been interpreted as a tentative defense against the ongoing pathologic mechanisms. With the demonstration that multiple cells possess YP, their propensity to be modulated, and their broad spectrum of activity on multiple signaling pathways, the YP have assumed the role of an adjustable system that can promote health in adults. Based on that, there is an ongoing effort to induce their activity as a therapeutic option, and natural compounds are an attractive alternative to the goal, possibly requiring only minimal changes in the life style. We review the most recent evidence of the potential of natural compounds in targeting the YP in the context of the most common pathologic condition of adult and elderly life.

The pharmacological effects of Berberine and its therapeutic potential in different diseases: Role of the phosphatidylinositol 3-kinase/AKT signaling pathway

The phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway plays a central role in cell growth and survival and is disturbed in various pathologies. The PI3K is a kinase that generates phosphatidylinositol-3,4,5-trisphosphate (PI (3-5) P3), as a second messenger responsible for the translocation of AKT to the plasma membrane and its activation. However, due to the crucial role of the PI3K/AKT pathway in regulation of cell survival processes, it has been introduced as a main therapeutic target for natural compounds during the progression of different pathologies. Berberine, a plant-derived isoquinone alkaloid, is known because of its anti-inflammatory, antioxidant, antidiabetic, and antitumor properties. The effect of this natural compound on cell survival processes has been shown to be mediated by modulation of the intracellular pathways. However, the effects of this natural compound on the PI3K/AKT pathway in various pathologies have not been reviewed so far. Therefore, this paper aims to review the PI3K/AKT-mediated effects of Berberine in different types of cancer, diabetes, cardiovascular, and central nervous system diseases.

Hyperoside Prevents Aβ42-Induced Neurotoxicity in PC12 Cells and Caenorhabditis elegans

Traditional Chinese medicines such as hyperoside-rich Acanthopanax senticosus and Crataegus pinnatifida have been confirmed to exhibit anti-oxidative stress properties. Hyperoside, the main ingredient of numerous antioxidant herbs, may have the ability to postpone the onset of neurodegenerative diseases. This study investigates the possible therapeutic mechanism of hyperoside as a natural antioxidant against Alzheimer's disease (AD) in Caenorhabditis elegans and PC12 cells. Specifically, hyperoside reduced reactive oxygen species (ROS) level and Aβ42-induced neurotoxicity in C. elegans worms. Meanwhile, hyperoside reduced ROS production and increased mitochondrial membrane potentialin Aβ42-induced PC12 cells, which possibly due to the increase of antioxidant enzymes activity and the diminution of malondialdehyde levels. Hoechst 33,342 staining and flow cytometry analysis results suggested that hyperoside reverses cell apoptosis. Network pharmacology predicts potentially relevant hyperoside targets and pathways in AD therapy. As anticipated, hyperoside reversed Aβ42-stimulated downregulation of the PI3K/Akt/Nrf2/HO-1. The PI3K inhibitor LY294002 partially abolished the protective capability of hyperoside. The results of molecular docking further indicated that the PI3K/Akt pathways may be involved in the protection of Aβ42-induced PC12 cells by hyperoside treatment. The study provides theoretical information for research and development of hyperoside as an antioxidant dietary supplement.

High-fat stimulation induces atrial neural remodeling by reducing NO production via the CRIF1/eNOS/P21 axi

BACKGROUND

Autonomic remodeling of the atria plays a pivotal role in the development of atrial fibrillation (AF) and exerts a substantial influence on the progression of this condition. Hyperlipidemia is a predisposing factor for AF, but its effect on atrial nerve remodeling is unclear. The primary goal of this study was to explore the possible mechanisms through which the consumption of a high-fat diet (HFD) induces remodeling of atrial nerves, and to identify novel targets for clinical intervention.

METHODS

Cell models were created in vitro by subjecting cells to palmitic acid (PA), while rat models were established by feeding them a high-fat diet. To investigate the interplay between cardiomyocytes and nerve cells in a co-culture system, we utilized Transwell cell culture plates featuring a pore size of 0.4 μm. The CCK-8 assay was employed to determine cell viability, fluorescent probe DCFH-DA and flow cytometry were utilized for measuring ROS levels, JC-1 was used to assess the mitochondrial membrane potential, the Griess method was employed to measure the nitric oxide (NO) level in the supernatant, a fluorescence-based method was used to measure ATP levels, and MitoTracker was utilized for assessing mitochondrial morphology. The expression of pertinent proteins was evaluated using western blotting (WB) and immunohistochemistry techniques. SNAP was used to treat nerve cells in order to replicate a high-NO atmosphere, and the level of nitroso was assessed using the iodoTMT reagent labeling method.

RESULTS

The study found that cardiomyocytes' mitochondrial morphology and function were impaired under high-fat stimulation, affecting nitric oxide (NO) production through the CRIF1/SIRT1/eNOS axis. In a coculture model, overexpression of eNOS in cardiomyocytes increased NO expression. Moreover, the increased Keap1 nitrosylation within neuronal cells facilitated the entry of Nrf2 into the nucleus, resulting in an augmentation of P21 transcription and a suppression of proliferation. Atrial neural remodeling occurred in the HFD rat model and was ameliorated by increasing myocardial tissue eNOS protein expression with trimetazidine (TMZ).

CONCLUSIONS

Neural remodeling is triggered by high-fat stimulation, which decreases the production of NO through the CRIF1/eNOS/P21 axis. Additionally, TMZ prevents neural remodeling and reduces the occurrence of AF by enhancing eNOS expression.

Antiplatelet drugs: Potential therapeutic options for the management of neurodegenerative diseases

The blood platelet plays an important role but often remains under-recognized in several vascular complications and associated diseases. Surprisingly, platelet hyperactivity and hyperaggregability have often been considered the critical risk factors for developing vascular dysfunctions in several neurodegenerative diseases (NDDs) like Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. In addition, platelet structural and functional impairments promote prothrombotic and proinflammatory environment that can aggravate the progression of several NDDs. These findings provide the rationale for using antiplatelet agents not only to prevent morbidity but also to reduce mortality caused by NDDs. Therefore, we thoroughly review the evidence supporting the potential pleiotropic effects of several novel classes of synthetic antiplatelet drugs, that is, cyclooxygenase inhibitors, adenosine diphosphate receptor antagonists, protease-activated receptor blockers, and glycoprotein IIb/IIIa receptor inhibitors in NDDs. Apart from this, the review also emphasizes the recent developments of selected natural antiplatelet phytochemicals belonging to key classes of plant-based bioactive compounds, including polyphenols, alkaloids, terpenoids, and flavonoids as potential therapeutic candidates in NDDs. We believe that the broad analysis of contemporary strategies and specific approaches for plausible therapeutic treatment for NDDs presented in this review could be helpful for further successful research in this area.

Neuroprotective Properties of Berberine: Molecular Mechanisms and Clinical Implications

Berberine (BBR), an isoquinoline alkaloid natural product, is isolated primarily from Coptis chinensis and other Berberis plants. BBR possesses various bioactivities, including antioxidant, anti-inflammation, anticancer, immune-regulation, and antimicrobial activities. Growing scientific evidence underscores BBR's substantial neuroprotective potential, prompting increased interest and scrutiny. In this comprehensive review, we elucidate the neuroprotective attributes of BBR, delineate the underlying molecular mechanisms, and assess its clinical safety and efficacy. The multifaceted molecular mechanisms responsible for BBR's neuroprotection encompass the attenuation of oxidative stress, mitigation of inflammatory responses, inhibition of apoptotic pathways, facilitation of autophagic processes, and modulation of CYP450 enzyme activities, neurotransmitter levels, and gut microbiota composition. Furthermore, BBR engages numerous signaling pathways, including the PI3K/Akt, NF-κB, AMPK, CREB, Nrf2, and MAPK pathways, to confer its neuroprotective effects. This comprehensive review aims to provide a substantial knowledge base, stimulate broader scientific discourse, and facilitate advancements in the application of BBR for neuroprotection.

Temperature- and chemical-induced neurotoxicity in zebrafish

Throughout their lives, humans encounter a plethora of substances capable of inducing neurotoxic effects, including drugs, heavy metals and pesticides. Neurotoxicity manifests when exposure to these chemicals disrupts the normal functioning of the nervous system, and some neurotoxic agents have been linked to neurodegenerative pathologies such as Parkinson's and Alzheimer's disease. The growing concern surrounding the neurotoxic impacts of both naturally occurring and man-made toxic substances necessitates the identification of animal models for rapid testing across a wide spectrum of substances and concentrations, and the utilization of tools capable of detecting nervous system alterations spanning from the molecular level up to the behavioural one. Zebrafish (Danio rerio) is gaining prominence in the field of neuroscience due to its versatility. The possibility of analysing all developmental stages (embryo, larva and adult), applying the most common "omics" approaches (transcriptomics, proteomics, lipidomics, etc.) and conducting a wide range of behavioural tests makes zebrafish an excellent model for neurotoxicity studies. This review delves into the main experimental approaches adopted and the main markers analysed in neurotoxicity studies in zebrafish, showing that neurotoxic phenomena can be triggered not only by exposure to chemical substances but also by fluctuations in temperature. The findings presented here serve as a valuable resource for the study of neurotoxicity in zebrafish and define new scenarios in ecotoxicology suggesting that alterations in temperature can synergistically compound the neurotoxic effects of chemical substances, intensifying their detrimental impact on fish populations.

Berberine Alleviates the Damage, Oxidative Stress and Mitochondrial Dysfunction of PC12 Cells Induced by High Glucose by Activating the KEAP1/Nrf2/ARE Pathway

Diabetic encephalopathy (DE) is one of the major chronic complications of diabetes mellitus. This study aims to investigate the inhibitory effect of berberine (BBR) on the damage of PC12 cells induced by high glucose (HG). Differentiated PC12 cells were treated with different concentrations of glucose/BBR. The cell morphology, cell viability, lactate dehydrogenase (LDH) activity, apoptosis, oxidative stress (OS), mitochondrial structure, mitochondrial membrane potential (MMP), mitochondrial complex I-V activity, and adenosine triphosphate (ATP) levels were evaluated. The mRNA and protein levels of the Keap1/Nrf2/ARE pathway-related genes were assessed by RT-qPCR and Western blot. High-dose BBR and HG jointly treated-PC12 cells were treated with Nrf2-specific inhibitor ML385 to further verify whether Nrf2 was the target of BBR. The results showed that BBR inhibited cell damage, OS, and mitochondrial dysfunction induced by HG. The inhibitory effect of high BBR was more significant. The Keap1/Nrf2/ARE pathway was inhibited in PC12 cells induced by HG. BBR could activate the Keap1/Nrf2/ARE pathway, thus up-regulating the expression levels of antioxidant enzymes. ML385 antagonized the ameliorating effect of BBR on OS and mitochondrial dysfunction. The conclusion is that BBR can activate the Keap1/Nrf2/ARE pathway, upregulate the expression patterns of antioxidant enzymes, and reduce cell damage, OS, and mitochondrial dysfunction of PC12 cells induced by HG.

Protective effects of dioscin against Parkinson's disease via regulating bile acid metabolism through remodeling gut microbiome/GLP-1 signaling

It is necessary to explore potent therapeutic agents via regulating gut microbiota and metabolism to combat Parkinson's disease (PD). Dioscin, a bioactive steroidal saponin, shows various activities. However, its effects and mechanisms against PD are limited. In this study, dioscin dramatically alleviated neuroinflammation and oxidative stress, and restored the disorders of mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). 16 S rDNA sequencing assay demonstrated that dioscin reversed MPTP-induced gut dysbiosis to decrease Firmicutes-to-Bacteroidetes ratio and the abundances of Enterococcus, Streptococcus, Bacteroides and Lactobacillus genera, which further inhibited bile salt hydrolase (BSH) activity and blocked bile acid (BA) deconjugation. Fecal microbiome transplantation test showed that the anti-PD effect of dioscin was gut microbiota-dependent. In addition, non-targeted fecal metabolomics assays revealed many differential metabolites in adjusting steroid biosynthesis and primary bile acid biosynthesis. Moreover, targeted bile acid metabolomics assay indicated that dioscin increased the levels of ursodeoxycholic acid, tauroursodeoxycholic acid, taurodeoxycholic acid and β-muricholic acid in feces and serum. In addition, ursodeoxycholic acid administration markedly improved the protective effects of dioscin against PD in mice. Mechanistic test indicated that dioscin significantly up-regulated the levels of takeda G protein-coupled receptor 5 (TGR5), glucagon-like peptide-1 receptor (GLP-1R), GLP-1, superoxide dismutase (SOD), and down-regulated NADPH oxidases 2 (NOX2) and nuclear factor-kappaB (NF-κB) levels. Our data indicated that dioscin ameliorated PD phenotype by restoring gut dysbiosis and regulating bile acid-mediated oxidative stress and neuroinflammation via targeting GLP-1 signal in MPTP-induced PD mice, suggesting that the compound should be considered as a prebiotic agent to treat PD in the future.

Nuclear factor erythrogen-2 associated factor 2 (Nrf2) signaling is an essential molecular pathway for the anti-aging effect of whey protein in the prefrontal cortex of aging rat model (Histological and Biochemical Study)

Aging is a highly complicated natural process. Brain aging is associated with remarkable neurodegenerative changes and oxidative damage. Whey protein (WP) has been mentioned to have an antioxidant property. Nuclear factor erythrogen-2 associated factor 2 (Nrf2) signaling pathway is an antioxidant defense system. Nrf2 activity declines with age so, its activation could be a promising therapeutic strategy for aging. This study aimed to explore the anti-aging role of WP against D-galactose (D-gal) induced age-related degenerative changes and oxidative damage in the prefrontal cortex (PFC) and investigate its underlying mechanisms. Forty adult male rats were divided into 4 groups; control, WP group received WP (28.77 mg/kg/day) by gastric tube on the 4th experimental week; D-gal (model group) received D-gal (300 mg/kg/day) intraperitoneally for 8 weeks and D-gal +WP group received WP on the 4th week of D-gal treatment. Specimens from PFC were obtained for biochemical, histological, immunohistochemical and western blot analysis. WP treatment in D-gal +WP group reduced lipid peroxidation, enhanced antioxidant enzyme activities, decreased advanced glycation end products level and improved the histological and ultrastructural alterations. Moreover, the number of neurons expressed the senescence marker; p21 and percentage area of the astrocytic marker; glial fibrillary acidic protein were significantly reduced. WP also enhanced Nrf2 pathway and its downstream targets; heme oxygenase-1 and NADPH quinone oxidoreductase 1. In conclusion WP alleviates the D-gal-induced PFC aging through activating Nrf2 pathway, reducing cell senescence and gliosis. So, it may be a potential therapeutic target to retard the aging process.

Experimental models of chemically induced Parkinson's disease in zebrafish at the embryonic larval stage: a systematic review

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra that results in a decrease in dopamine levels, resulting in motor-type disturbances. Different vertebrate models, such as rodents and fish, have been used to study PD. In recent decades, Danio rerio (zebrafish) has emerged as a potential model for the investigation of neurodegenerative diseases due to its homology to the nervous system of humans. In this context, this systematic review aimed to identify publications that reported the utilization of neurotoxins as an experimental model of parkinsonism in zebrafish embryos and larvae. Ultimately, 56 articles were identified by searching three databases (PubMed, Web of Science, and Google Scholar). Seventeen studies using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 4 1-methyl-4-phenylpyridinium (MPP+), 24 6-hydroxydopamine (6-OHDA), 6 paraquat/diquat, 2 rotenone, and 6 articles using other types of unusual neurotoxins to induce PD were selected. Neurobehavioral function, such as motor activity, dopaminergic neuron markers, oxidative stress biomarkers, and other relevant parameters in the zebrafish embryo-larval model were examined. In summary, this review provides information to help researchers determine which chemical model is suitable to study experimental parkinsonism, according to the effects induced by neurotoxins in zebrafish embryos and larvae.

Insight into mitochondrial dysfunction mediated by clozapine-induced inhibition of PGRMC1 in PC12 cells

Clozapine is usually considered as the last resort for treatment-resistant schizophrenia (TRS). However, it shows limited efficacy in cognition improvement. Moreover, the metabolic side effects induced by clozapine can aggravate cognitive impairment, which is closely related to its neurotoxicity. Nevertheless, the mechanisms underlying clozapine's neurotoxicity remain largely elusive. In this study, PC12 cells were simultaneously treated with different concentrations (0μM, 10μM, 20μM, 40μM and 80μM) of clozapine and AG205 which functions as a blocking reagent of progesterone receptor membrane component 1 (PGRMC1). In addition, we examined the effect of PGRMC1 in clozapine-induced neurotoxicity through overexpressing or downregulating PGRMC1. Molecular docking and surface plasmon resonance (SPR) analysis indicated that clozapine and AG205 inhibited the binding of endogenous progesterone to PGRMC1. The results showed that high concentration of clozapine and AG205 induced a significant increase in cytotoxicity, reactive oxygen species (ROS) accumulation and mitochondrial membrane potential (MMP) collapse, all of which were worsened as concentration increases, while overexpression of PGRMC1 reverted the above toxic effect of clozapine on PC12 cells. Furthermore, clozapine and AG205 also downregulated the expression of PGRMC1, glucagon-like peptide-1 receptor (GLP-1R) and mitofusin2 (Mfn2). Interestingly, overexpression of PGRMC1 could revert these effects. Our data suggest that overexpression of PGRMC1 in PC12 cells prevents and restores clozapine-induced oxidative and mitochondrial damage. We propose PGRMC1 activation as a promising therapeutic strategy for clozapine-induced neurotoxicity to facilitate the relief of neuronal damage.

Phenolic compounds from the flowers of Rosa hugonis Hemsl. and their neuroprotective effects

The fragrant flowers of Rosa hugonis Hemsl. Contain abundant valuable rose oil and carotenoids. However, phytochemical investigation of this resource rich in phenolics with neuroprotective activity in vitro has been rarely reported. Purification of the 70% ethanol extracts from the flowers of R. hugonis by various chromatographic methods resulted in the isolation and characterization of five undescribed acylated flavonoid glycosides (Hugonisflavonoid A-E) together with forty known phenolics. The chemical structures of the undescribed compounds were elucidated by extensive analysis of their spectroscopic data and chemical methods. All the isolates were found from R. hugonis for the first time and evaluated for their neuroprotective effects on 6-OHDA induced injury in PC12 cells. Seventeen compounds displayed remarkable protective effects at concentrations of 10 μM. Hugonisflavonoid E can reduce excessive reactive oxygen species and up-regulate mRNA expression levels of superoxide dismutase 1 and catalase. Additionally, hugonisflavonoid E activated the phosphorylated proteins such as PDK1, Akt and GSk-3β. These findings suggested that R. hugonis could be a potential source for neuroprotective agents.

Protective effects of berberine against β-amyloid-induced neurotoxicity in HT22 cells via the Nrf2/HO-1 pathway

Neuronal apoptosis has been found to have a pivotal role in the course of Alzheimer's disease (AD). Berberine (BBR), a potent antioxidant, occurs in plants such as Berberis, Phellodendron chinense, and Hydrastis canadensis. In this study, a neuronal apoptotic model was established in vitro using HT22 cells induced by Aβ_25-35 to explore whether BBR contributes to protecting neurons against Aβ_25-35-induced neurotoxicity, as well as its potential mechanisms. BBR was applied to HT22 cells for 1 h prior to exposing the cells to Aβ_25-35 for 24 h. A CCK-8 assay was utilized to assess cell viability, and Annexin V - fluorescein isothiocyanate (FITC)/propidium iodide and Hoechst 33342 fluorescence staining were used to measure the rate of cell apoptosis. Existing scientific literature was also reviewed to further determine the effects of BBR on ROS production and mitochondrial function in HT22 cells. Furthermore, the expressions of proteins, including cytochrome C, cleaved caspase-3, p-p65, p65, and Nrf2/HO-1 antioxidant axis were assessed by Western blotting. The data indicated that BBR markedly improved cell viability, inhibited apoptosis and intracellular ROS levels, improved mitochondrial membrane potentials, decreased the rate of p-p65/p65, cytochrome C, and cleaved caspase-3, and intensified the activity of Nrf2/HO-1 antioxidants in HT22 cells. Overall, the findings indicated that BBR provides a certain level of neuroprotectiveness in HT22 cells exposed to Aβ_25-35 via relieving oxidative stress, as well as by restraining the mitochondrial pathway of cellular apoptosis. In addition, the restraint of NF-κB activity and sensitization of the Nrf2/HO-1 antioxidant axis, which together are intimately involved in the neuroprotection of BBR, may be possible mechanisms accounting for its effectiveness against Aβ_25-35in vitro.

Natural compounds regulate the PI3K/Akt/GSK3β pathway in myocardial ischemia-reperfusion injury

The PI3K/Akt/GSK3β pathway is crucial in regulating cardiomyocyte growth and survival. It has been shown that activation of this pathway alleviates the negative impact of ischemia-reperfusion. Glycogen synthase kinase-3 (GSK3β) induces apoptosis through stimulation of transcription factors, and its phosphorylation has been suggested as a new therapeutic target for myocardial ischemia-reperfusion injury (MIRI). GSK3β regulatory role is mediated by the reperfusion injury salvage kinase (RISK) pathway, and its inhibition by Akt activation blocks mitochondrial permeability transition pore (mPTP) opening and enhances myocardial survival. The present article discusses the involvement of the PI3K/Akt/GSK3β pathway in cardioprotective effects of natural products against MIRI.Abbreviations: Akt: protein kinase B; AMPK: AMP-activated protein kinase; ATP: adenosine triphosphate; Bad: bcl2-associated agonist of cell death; Bax: bcl2-associated x protein; Bcl-2: B-cell lymphoma 2; CK-MB: Creatine kinase-MB; CRP: C-reactive-protein; cTnI: cardiac troponin I; EGCG: Epigallocatechin-3-gallate; Enos: endothelial nitric oxide synthase; ER: endoplasmic reticulum; ERK ½: extracellular signal‑regulated protein kinase ½; GSK3β: glycogen synthase kinase-3; GSRd: Ginsenoside Rd; GSH: glutathione; GSSG: glutathione disulfide; HO-1: heme oxygenase-1; HR: hypoxia/reoxygenation; HSYA: Hydroxysafflor Yellow A; ICAM-1: Intercellular Adhesion Molecule 1; IKK-b: IκB kinase; IL: interleukin; IPoC: Ischemic postconditioning; IRI: ischemia-reperfusion injury; JNK: c-Jun N-terminal kinase; Keap1: kelch-like ECH-associated protein- 1; LDH: lactate dehydrogenase; LVEDP: left ventricular end diastolic pressure; LVP: left ventricle pressure; LVSP: left ventricular systolic pressure; MAPK: mitogen-activated protein kinase; MDA: malondialdehyde; MIRI: myocardial ischemia-reperfusion injury; MnSOD: manganese superoxide dismutase; mPTP: mitochondrial permeability transition pore; mtHKII: mitochondria-bound hexokinase II; Nrf-1: nuclear respiratory factor 1; Nrf2: nuclear factor erythroid 2-related factor; NO: nitric oxide; PGC-1α: peroxisome proliferator‑activated receptor γ coactivator‑1α; PI3K: phosphoinositide 3-kinases; RISK: reperfusion injury salvage kinase; ROS: reactive oxygen species; RSV: Resveratrol; SOD: superoxide dismutase; TFAM: transcription factor A mitochondrial; TNF-α: tumor necrosis factor-alpha; VEGF-B: vascular endothelial growth factor B.

New insights into the role of berberine against 3-nitropropionic acid-induced striatal neurotoxicity: Possible role of BDNF-TrkB-PI3K/Akt and NF-κB signaling

Berberine (Berb) is a major alkaloid with potential protective effects against multiple neurological disorders. Nevertheless, its positive effect against 3-nitropropionic acid (3NP) induced Huntington's disease (HD) modulation has not been fully elucidated. Accordingly, this study aimed to assess the possible action mechanisms of Berb against such neurotoxicity using an in vivo rats model pretreated with Berb (100 mg/kg, p.o.) alongisde 3NP (10 mg/kg, i.p.) at the latter 2 weeks to induce HD symptoms. Berb revealed its capacity to partially protect the striatum as mediated via the activation of BDNF-TrkB-PI3K/Akt signaling and amelioration of neuroinflammation status by blocking NF-κB p65 with a concomitant reduction in its downstream cytokines TNF-α and IL-1β. Moreover, its antioxidant potential was evidenced from induction of Nrf2 and GSH levels concurrent with a reduction in MDA level. Furthermore, Berb anti-apoptotic effect was manifested through the induction of pro-survival protein (Bcl-2) and down-regulation of the apoptosis biomarker (caspase-3). Finally, Berb intake ascertained its striatum protective action by improving the motor and histopathological abnormalities with concomitant dopamine restoration. In conclusion, Berb appears to modulate 3NP-induced neurotoxicity by moderating BDNF-TrkB-PI3K/Akt signaling besides its anti-inflammatory, antioxidant, as well as anti-apoptotic effect.

Development of a Mitochondrial Targeting Lipid Nanoparticle Encapsulating Berberine

Delivering drugs to mitochondria, the main source of energy in neurons, can be a useful therapeutic strategy for the treatment of neurodegenerative diseases. Berberine (BBR), an isoquinoline alkaloid, acts on mitochondria and is involved in mechanisms associated with the normalization and regulation of intracellular metabolism. Therefore, BBR has attracted considerable interest as a possible therapeutic drug for neurodegenerative diseases. While BBR has been reported to act on mitochondria, there are few reports on the efficient delivery of BBR into mitochondria. This paper reports on the mitochondrial delivery of BBR using a lipid nanoparticle (LNP), a "MITO-Porter" that targets mitochondria, and its pharmacological action in Neuro2a cells, a model neuroblastoma. A MITO-Porter containing encapsulated BBR (MITO-Porter (BBR)) was prepared. Treatment with MITO-Porter (BBR) increased the amount of BBR that accumulated in mitochondria compared with a treatment with naked BBR. Treatment with MITO-Porter (BBR) resulted in increased ATP production in Neuro2a cells, which are important for maintaining life phenomena, compared with treatment with naked BBR. Treatment with MITO-Porter (BBR) also increased the level of expression of mitochondrial ubiquitin ligase (MITOL), which is involved in mitochondrial quality control. Our findings indicate that increasing the accumulation of BBR into mitochondria is important for inducing enhanced pharmacological actions. The use of this system has the potential for being important in terms of the regulation of the metabolic mechanism of mitochondria in nerve cells.

Dopamine Release Impairments Accompany Locomotor and Cognitive Deficiencies in Rotenone-Treated Parkinson's Disease Model Zebrafish

In this work, we carried out neurochemical and behavioral analysis of zebrafish (Danio rerio) treated with rotenone, an agent used to chemically induce a syndrome resembling Parkinson's disease (PD). Dopamine release, measured with fast-scan cyclic voltammetry (FSCV) at carbon-fiber electrodes in acutely harvested whole brains, was about 30% of that found in controls. Uptake, represented by the first order rate constant (k) and the half-life (t1/2) determined by nonlinear regression modeling of the stimulated release plots, was also diminished. Behavioral analysis revealed that rotenone treatment increased the time required for zebrafish to reach a reward within a maze by more than 50% and caused fish to select the wrong pathway, suggesting that latent learning was impaired. Additionally, zebrafish treated with rotenone suffered from diminished locomotor activity, swimming shorter distances with lower mean velocity and acceleration. Thus, the neurochemical and behavioral approaches, as applied, were able to resolve rotenone-induced differences in key parameters. This approach may be effective for screening therapies in this and other models of neurodegeneration.

Role of Nrf2 Pathway Activation in Neurological Disorder: A Brief Review

Oxidative stress plays a crucial role in the emergence of numerous neurodegenerative diseases, with protein accumulation and mitochondrial damage, which result in neurological disorders. To minimize oxidative stress, several defensive mechanisms protect nerve cells by releasing antioxidants such as nuclear erythroid factor2 (Nrf2)-Kelch-like ECH-associated protein1 (Keap1) signaling pathway activation has been proved to be a prospective treatment to reduce oxidative stress and neuroinflammation for protection of neurons in a variety of neurological disorders. In this review, we focus beneficial role of Nrf2 in Alzheimer’s and Parkinson’s diseases. Nrf2 is proved to be a master regulator of antioxidants by releasing over 250 cytoprotective genes aimed at oxidative stress and neuroinflammation. In animal studies Nrf2 activation is proved to improve autophagy, mitochondrial biogenesis, and Suppression of inflammatory cytokinin which protects neuronal cells and inhibit progressive neurodegeneration.

Zebrafish as a model organism for neurodegenerative disease

The zebrafish is increasingly recognized as a model organism for translational research into human neuropathology. The zebrafish brain exhibits fundamental resemblance with human neuroanatomical and neurochemical pathways, and hallmarks of human brain pathology such as protein aggregation, neuronal degeneration and activation of glial cells, for example, can be modeled and recapitulated in the fish central nervous system. Genetic manipulation, imaging, and drug screening are areas where zebrafish excel with the ease of introducing mutations and transgenes, the expression of fluorescent markers that can be detected in vivo in the transparent larval stages overtime, and simple treatment of large numbers of fish larvae at once followed by automated screening and imaging. In this review, we summarize how zebrafish have successfully been employed to model human neurodegenerative diseases such as Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, and Huntington’s disease. We discuss advantages and disadvantages of choosing zebrafish as a model for these neurodegenerative conditions.

Neurohormetic phytochemicals in the pathogenesis of neurodegenerative diseases

The world population is progressively ageing, assuming an enormous social and health challenge. As the world ages, neurodegenerative diseases are on the rise. Regarding the progressive nature of these diseases, none of the neurodegenerative diseases are curable at date, and the existing treatments can only help relieve the symptoms or slow the progression. Recently, hormesis has increased attention in the treatment of age-related neurodegenerative diseases. The concept of hormesis refers to a biphasic dose-response phenomenon, where low levels of the drug or stress exert protective of beneficial effects and high doses deleterious or toxic effects. Neurohormesis, as the adaptive aspect of hormetic dose responses in neurons, has been shown to slow the onset of neurodegenerative diseases and reduce the damages caused by aging, stroke, and traumatic brain injury. Hormesis was also observed to modulate anxiety, stress, pain, and the severity of seizure. Thus, neurohormesis can be considered as a potentially innovative approach in the treatment of neurodegenerative and other neurologic disorders. Herbal medicinal products and supplements are often considered health resources with many applications. The hormesis phenomenon in medicinal plants is valuable and several studies have shown that hormetic mechanisms of bioactive compounds can prevent or ameliorate the neurodegenerative pathogenesis in animal models of Alzheimer’s and Parkinson’s diseases. Moreover, the hormesis activity of phytochemicals has been evaluated in other neurological disorders such as Autism and Huntington’s disease. In this review, the neurohormetic dose–response concept and the possible underlying neuroprotection mechanisms are discussed. Different neurohormetic phytochemicals used for the better management of neurodegenerative diseases, the rationale for using them, and the key findings of their studies are also reviewed.

Can Berberine Serve as a New Therapy for Parkinson's Disease?

Parkinson's disease (PD) is a neurodegenerative disorder characterized by dopaminergic neurodegeneration and deposition of alpha-synuclein. Mechanisms associated with PD etiology include oxidative stress, apoptosis, autophagy, and abnormalities in neurotransmission, to name a few. Drugs used to treat PD have shown significant limitations in their efficacy. Therefore, recent focus has been placed on the potential of active plant ingredients as alternative, complementary, and efficient treatments. Berberine is an isoquinoline alkaloid that has shown promise as a pharmacological treatment in PD, given its ability to modulate several molecular pathway associated with the disease. Here, we review contemporary knowledge supporting the need to further characterize berberine as a potential treatment for PD.

Activation of Atg7-dependent autophagy by a novel inhibitor of the Keap1-Nrf2 protein-protein interaction from Penthorum chinense Pursh. attenuates 6-hydroxydopamine-induced ferroptosis in zebrafish and dopaminergic neurons

The death of dopaminergic neurons is a dominant factor during the occurrence and development of Parkinson's disease (PD). Previous studies demonstrated that ferroptosis is implicated in the death of dopaminergic neurons. Besides, polyphenols have been proven to be effective in preventing the death of dopaminergic neurons. This work aims to explore the neuroprotective effect and mechanism of thonningianin A (Th A), a polyphenolic compound in natural plant foods, against 6-hydroxydopamine (6-OHDA)-induced ferroptosis in dopaminergic cells. The results of molecular docking and other binding assays collectively demonstrated that Th A can strongly target the Kelch domain of Keap1. Th A treatment significantly facilitated the nuclear factor erythroid 2-like 2 (Nrf2) nuclear translocation and subsequently increased the heme oxygenase-1 (HO-1) protein level through inhibiting the protein-protein interaction (PPI) of Keap1 and Nrf2. Compared with the nomifensine (Nomi) treatment, Th A had a more potent protective effect on 6-OHDA-induced ferroptosis during PD pathology in zebrafish, which was associated with assuaging the reduction of the total swimming distance, glutathione (GSH) depletion, iron accumulation, lipid peroxidation, and aggregation of α-synuclein (α-syn). Furthermore, Th A also exhibited a strong protective effect against 6-OHDA-induced ferroptosis in vitro in the human neuroblastoma cell line SH-SY5Y. Th A degraded Keap1 protein through activating Atg7-dependent autophagy. Additionally, Th A treatment facilitated the degradation of Keap1 protein by promoting the interaction between p62/SQSTM1 (sequestosome 1, hereafter referred to as p62) and Keap1. Taken together, our findings indicated that Th A protects dopaminergic cells against 6-OHDA-induced ferroptosis through activating the Nrf2-based cytoprotective system, thus enabling a potential application of Keap1-Nrf2 PPI inhibitors in the restraint of ferroptosis and treatment of PD.

Bcl-xL is required for the protective effects of low-dose berberine against doxorubicin-induced cardiotoxicity through blocking apoptosis and activating mitophagy-mediated ROS elimination

BACKGROUND

Doxorubicin (DOX)-induced cardiotoxicity is related to abnormal autophagy and apoptosis in the heart. Berberine (BBR) is a well-known natural compound with potential cardioprotective and autophagic modulatory properties.

HYPOTHESIS

We hypothesized that BBR ameliorates DOX-induced cardiotoxicity by balancing cardiomyocyte autophagy and apoptosis.

STUDY DESIGN/METHODS

DOX was used to generate in vivo and in vitro cardiotoxic models. Larval and adult zebrafish and human AC16 cells were used to study (i) the effects of BBR on autophagy and apoptosis upon DOX challenge and (ii) the underlying mechanisms.

RESULTS

BBR protected AC16 cells and zebrafish hearts from DOX-induced cytotoxicity and apoptosis. Bcl-xL knockdown in AC16 cells and zebrafish demonstrated that Bcl-xL is required for BBR's anti-apoptotic activity. DOX treatment promoted Beclin1 binding to Bcl-xL, disrupted mitophagy, and increased ROS accumulation in AC16 cells. In AC16 cells and zebrafish hearts, pretreatment with BBR enhanced mitophagy via dissociation of the Bcl-xL-Beclin1 complex and decreased ROS accumulation. Inhibition of autophagy attenuated this effect of BBR. Intriguingly, BBR increased Bcl-xL binding to Bnip3, sequestration, and mitophagy, indicating that Bcl-xL may play a beneficial role in BBR-induced mitophagy. Additionally, BBR significantly ameliorated DOX-induced cardiac dysfunction in zebrafish, whereas Bcl-xL knockdown abolished this effect. Notably, we discovered that BBR exerts biphasic dose-response effects in response to DOX; the cardioprotective properties were observed upon treatment with low-dose BBR (≤ 1 μM in cells, ≤ 10 μM in zebrafish), but not with relatively high-dose BBR.

CONCLUSION

These findings indicate that the protective effects of low-dose BBR against DOX-induced cardiotoxicity are mediated by Bcl-xL.

Berberine: A Promising Treatment for Neurodegenerative Diseases

Berberine, as a natural alkaloid compound, is characterized by a diversity of pharmacological effects. In recent years, many researches focused on the role of berberine in central nervous system diseases. Among them, the effect of berberine on neurodegenerative diseases has received widespread attention, for example Alzheimer's disease, Parkinson's disease, Huntington's disease, and so on. Recent evidence suggests that berberine inhibits the production of neuroinflammation, oxidative, and endoplasmic reticulum stress. These effects can further reduce neuron damage and apoptosis. Although the current research has made some progress, its specific mechanism still needs to be further explored. This review provides an overview of berberine in neurodegenerative diseases and its related mechanisms, and also provides new ideas for future research on berberine.

Novel mechanistic insight on the neuroprotective effect of berberine: The role of PPARδ for antioxidant action

Cerebral ischemic stroke ranks the second leading cause of death and the third leading cause of disability in lifetime all around the world, urgently necessitating effective therapeutic interventions. Reactive oxygen species (ROS) have been implicated in stroke pathogenesis and peroxisome proliferator-activated receptors (PPARs) are prominent targets for ROS management. Although recent research has shown antioxidant effect of berberine (BBR), little is known regarding its effect upon ROS-PPARs signaling in stroke. The aim of this study is to explore whether BBR could target on ROS-PPARs pathway to ameliorate middle cerebral artery occlusion (MCAO)-induced stroke. Herein, we report that BBR is able to scavenge ROS in oxidation-damaged C17.2 neural stem cells and stroked mice. PPARδ, rather than PPARα or PPARγ, is involved in the anti-ROS effect of BBR, as evidenced by the siRNA transfection and specific antagonist treatment data. Further, we have found BBR could upregulate NF-E2 related factor-1/2 (NRF1/2) and NAD(P)H:quinone oxidoreductase 1 (NQO1) following a PPARδ-dependent manner. Mechanistic study has revealed that BBR acts as a potent ligand (Kd = 290 ± 92 nM) to activate PPARδ and initiates the transcriptional regulation functions, thus promoting the expression of PPARδ, NRF1, NRF2 and NQO1. Collectively, our results indicate that BBR confers neuroprotective effects by activating PPARδ to scavenge ROS, providing a novel mechanistic insight for the antioxidant action of BBR.

Therapeutic Efficacies of Berberine against Neurological Disorders: An Update of Pharmacological Effects and Mechanisms

Neurological disorders are ranked as the leading cause of disability and the second leading cause of death worldwide, underscoring an urgent necessity to develop novel pharmacotherapies. Berberine (BBR) is a well-known phytochemical isolated from a number of medicinal herbs. BBR has attracted much interest for its broad range of pharmacological actions in treating and/or managing neurological disorders. The discoveries in basic and clinical studies of the effects of BBR on neurological disorders in the last decade have provided novel evidence to support the potential therapeutical efficacies of BBR in treating neurological diseases. In this review, we summarized the pharmacological properties and therapeutic applications of BBR against neurological disorders in the last decade. We also emphasized the major pathways modulated by BBR, which provides firm evidence for BBR as a promising drug candidate for neurological disorders.

Chemically induced models of Parkinson's disease

Environmental toxins are harmful substances detrimental to humans. Constant exposure to these fatal neurotoxins can cause various neurodegenerative disorders. Although poisonous, specific neurotoxins at optimal concentrations mimic the clinical features of neurodegenerative diseases in several animal models. Such chemically-induced model systems are beneficial in deciphering the molecular mechanisms of neurodegeneration and drug screening for these disorders. One such neurotoxin is 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a widely used chemical that recapitulates Parkinsonian features in various animal models. Apart from MPTP, other neurotoxins like 6-hydroxydopamine (6-OHDA), paraquat, rotenone also induce specific clinical features of Parkinson's disease in animal models. These chemically-induced Parkinson's disease models are playing a crucial role in understanding Parkinson's disease onset, pathology, and novel therapeutics. In this review, we provide a concise overview of various neurotoxins that can recapitulate Parkinsonian features in different in vivo and in vitro model systems specifically focusing on the different treatment methodologies of neurotoxins.

Pharmacological Modulation of Nrf2/HO-1 Signaling Pathway as a Therapeutic Target of Parkinson's Disease

Parkinson’s disease (PD) is a complex neurodegenerative disorder featuring both motor and nonmotor symptoms associated with a progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Oxidative stress (OS) has been implicated in the pathogenesis of PD. Genetic and environmental factors can produce OS, which has been implicated as a core contributor to the initiation and progression of PD through the degeneration of dopaminergic neurons. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) orchestrates activation of multiple protective genes, including heme oxygenase-1 (HO-1), which protects cells from OS. Nrf2 has also been shown to exert anti-inflammatory effects and modulate both mitochondrial function and biogenesis. Recently, a series of studies have reported that different bioactive compounds were shown to be able to activate Nrf2/antioxidant response element (ARE) and can ameliorate PD-associated neurotoxin, both in animal models and in tissue culture. In this review, we briefly overview the sources of OS and the association between OS and the pathogenesis of PD. Then, we provided a concise overview of Nrf2/ARE pathway and delineated the role played by activation of Nrf2/HO-1 in PD. At last, we expand our discussion to the neuroprotective effects of pharmacological modulation of Nrf2/HO-1 by bioactive compounds and the potential application of Nrf2 activators for the treatment of PD. This review suggests that pharmacological modulation of Nrf2/HO-1 signaling pathway by bioactive compounds is a therapeutic target of PD.

Application and advantages of zebrafish model in the study of neurovascular unit

The concept of "Neurovascular Unit" (NVU) was put forward, so that the research goal of Central Nervous System (CNS) diseases gradually transitioned from a single neuron to the structural and functional integrity of the NVU. Zebrafish has the advantages of high homology with human genes, strong reproductive capacity and visualization of neural circuits, so it has become an emerging model organism for NVU research and has been applied to a variety of CNS diseases. Based on CNKI (https://www.cnki.net/) and PubMed (https://pubmed.ncbi.nlm.nih.gov/about/) databases, the author of this article sorted out the relevant literature, analyzed the construction of a zebrafish model of various CNS diseases，and the use of diagrams showed the application of zebrafish in the NVU, revealed its relationship, which would provide new methods and references for the treatment and research of CNS diseases.

Treatment of Parkinson's disease in Zebrafish model with a berberine derivative capable of crossing blood brain barrier, targeting mitochondria, and convenient for bioimaging experiments

Berberine is a famous alkaloid extracted from Berberis plants and has been widely used as medications and functional food additives. Recent studies reveal that berberine exhibits neuroprotective activity in animal models of Parkinson's disease (PD), the second most prevalent neurodegenerative disorders all over the world. However, the actual site of anti-PD action of berberine remains largely unknown. To this end, we employed a fluorescently labeled berberine derivative BBRP to investigate the subcellular localization and blood brain barrier (BBB) permeability in a cellular model of PD and zebrafish PD model. Biological investigations revealed that BBRP retained the neuroprotective activity of berberine against PD-like symptoms in PC12 cells and zebrafish, such as protecting 6-OHDA induced cell death, relieving MPTP induced PD-like behavior and increasing dopaminergic neuron loss in zebrafish. We also found that BBRP could readily penetrate BBB and function in the brain of zebrafish suffering from PD. Subcellular localization study indicated that BBRP could rapidly and specifically accumulate in mitochondria of PC12 cells when it exerted anti-PD effect. In addition, BBRP could suppress accumulation of Pink1 protein and inhibit the overexpression of LC3 protein in 6-OHDA damaged cells. All these results suggested that the potential site of action of berberine is mitochondria in the brain under the PD condition. Therefore, the findings described herein would be useful for further development of berberine as an anti-PD drug.

Modeling Parkinson's Disease: Not Only Rodents?

Parkinson’s disease (PD) is a common chronic progressive multifactorial neurodegenerative disease. In most cases, PD develops as a sporadic idiopathic disease. However, in 10%–15% of all patients, Mendelian inheritance of the disease is observed in an autosomal dominant or autosomal recessive manner. To date, mutations in seven genes have been convincingly confirmed as causative in typical familial forms of PD, i.e., SNCA, LRRK2, VPS35, PRKN, PINK1, GBA, and DJ-1. Family and genome-wide association studies have also identified a number of candidate disease genes and a common genetic variability at 90 loci has been linked to risk for PD. The analysis of the biological function of both proven and candidate genes made it possible to conclude that mitochondrial dysfunction, lysosomal dysfunction, impaired exosomal transport, and immunological processes can play important roles in the development of the pathological process of PD. The mechanisms of initiation of the pathological process and its earliest stages remain unclear. The study of the early stages of the disease (before the first motor symptoms appear) is extremely complicated by the long preclinical period. In addition, at present, the possibility of performing complex biochemical and molecular biological studies familial forms of PD is limited. However, in this case, the analysis of the state of the central nervous system can only be assessed by indirect signs, such as the level of metabolites in the cerebrospinal fluid, peripheral blood, and other biological fluids. One of the potential solutions to this problem is the analysis of disease models, in which it is possible to conduct a detailed in-depth study of all aspects of the pathological process, starting from its earliest stages. Many modeling options are available currently. An analysis of studies published in the 2000s suggests that toxic models in rodents are used in the vast majority of cases. However, interesting and important data for understanding the pathogenesis of PD can be obtained from other in vivo models. Within the framework of this review, we will consider various models of PD that were created using various living organisms, from unicellular yeast (Saccharomyces cerevisiae) and invertebrate (Nematode and Drosophila) forms to various mammalian species.

Protective Mechanism of Berberine on Human Retinal Pigment Epithelial Cells against Apoptosis Induced by Hydrogen Peroxide via the Stimulation of Autophagy

Age-related macular degeneration (AMD) is a major cause of severe and irreversible vision loss with limited effective therapies. Diminished autophagy and increased oxidative damage caused by ROS in the retinal pigment epithelium (RPE) have been implicated in the pathogenesis of AMD, and strategies aimed at enhancing autophagy are likely to protect these cells from oxidative damage. We have previously shown that berberine (BBR), an isoquinoline alkaloid isolated from Chinese herbs, was able to protect human RPE cells from H₂O₂-induced oxidative damage through AMPK activation. However, the precise mechanisms behind this protective effect remain unclear. Given the essential role of AMPK in autophagy activation, we postulated that BBR may confer protection against H₂O₂-induced oxidative damage by stimulating AMPK-dependent autophagy. Our results showed that BBR was able to induce autophagy in D407 cells, whereas autophagy inhibitor PIKIII or silencing of LC3B blocked the protective effect of BBR. Further analysis showed that BBR activated the AMPK/mTOR/ULK1 signaling pathways and that both pharmacological and genetic inhibitions of the AMPK pathway abolished the autophagy-stimulating effect of BBR. Similar results were obtained in primary cultured human RPE cells. Taken together, these results demonstrate that BBR is able to stimulate autophagy in D407 cells via the activation of AMPK pathway and that its protective effect against H₂O₂-induced oxidative damage relies on its autophagy-modulatory effect. Our findings also provide evidence to support the potential application of BBR in preventing and treating AMD.

Pentraxin 3 secreted by human adipose-derived stem cells promotes dopaminergic neuron repair in Parkinson's disease via the inhibition of apoptosis

Although adipose-derived human mesenchymal stem cell (hADSC) transplantation has recently emerged as a promising therapeutic modality for Parkinson's disease (PD), its underlying mechanism of action has not been fully elucidated. This study evaluated the therapeutic effects of stereotaxic injection of hADSCs in the striatum of the 6-OHDA-induced mouse model. Furthermore, an in vitro PD model was constructed using tissue-organized brain slices. The therapeutic effect was also evaluated using a co-culture of the hADSCs and 6-OHDA-treated brain slice. The analysis of hADSC exocrine proteins using RNA-sequencing, human protein cytokine arrays, and label-free quantitative proteomics identified key extracellular factors in the hADSC secretion environment. The degeneration and apoptosis of the dopaminergic neurons were measured in the PD samples in vivo and in vitro, and the beneficial effects were evaluated using quantitative reverse transcription-polymerase chain reaction, western blotting, Fluoro-Jade C, TUNEL assay, and immunofluorescence analysis. This study found that hADSCs protected the dopaminergic neurons in the in vivo and vitro models. We identified Pentraxin 3 (PTX3) as a key extracellular factor in the hADSC secretion environment. Moreover, we found that human recombinant PTX3 (rhPTX3) treatment could rescue the pathophysiological behavior of the PD mice in vivo, prevent dopaminergic neuronal death, and increase neuronal terminals in the ventral tegmental area + substantia nigra pars compacta and striatum in the PD brain slices in vitro. Furthermore, testing of the pro-apoptotic markers in the PD mouse brain following rhPTX3 treatment revealed that rhPTX3 can prevent apoptosis and degeneration of the dopaminergic neurons. This study discovered that PTX3, a hADSC-secreted protein, potentially protected the dopaminergic neurons against apoptosis and degeneration during PD progression and improved motor performance in PD mice, indicating the possible mechanism of action of hADSC replacement therapy for PD. Thus, our study discovered potential translational implications for the development of PTX3-based therapeutics for PD.

Pinocembrin-7-Methylether Protects SH-SY5Y Cells Against 6-Hydroxydopamine-Induced Neurotoxicity via Modulating Nrf2 Induction Through AKT and ERK Pathways

The present study aimed to evaluate the neuroprotective effects and underlying mechanisms of pinocembrin-7-methylether (PME), a natural bioflavonoid, in 6-hydroxydopamine (6-OHDA)-induced models of Parkinson's disease in vivo and in vitro. First, we found that PME decreased apoptosis in 6-OHDA-intoxicated SH-SY5Y cells. PME also blocked several 6-OHDA-induced mitochondrial apoptotic cascades, including loss of mitochondrial membrane potential, caspase 3 and PARP activation, and a decrease in the Bcl-2/Bax ratio. Also, PME suppressed 6-OHDA-induced oxidative stress while increasing antioxidant enzymatic activity. Further investigations indicated that PME significantly enhanced nuclear accumulation of Nrf2, improved ARE promoter activity, and upregulated HO-1 and NQO1 expression levels. In addition, siRNA-mediated Nrf2 knockdown abolished PME-induced anti-oxidative and anti-apoptotic effects. Interestingly, we found that PME promoted phosphorylation of AKT and ERK, whereas pharmacological inhibition of AKT or ERK pathways diminished PME-induced Nrf2 activation and protective actions. Moreover, PME attenuated 6-OHDA-induced loss of dopaminergic neurons and ameliorated locomotor deficiency in zebrafish, supporting the neuroprotective actions of PME in vivo. In summary, we found that PME conferred neuroprotection against 6-OHDA-induced neurotoxicity in PD models in vivo and in vitro. Taken together, our findings suggest that activation of Nrf2/ARE/HO-1 signaling cascades contributes to PME-induced anti-oxidative and neuroprotective actions, which are at least partially mediated by AKT and ERK pathways.

MicroRNA-1297 suppressed the Akt/GSK3 signaling pathway and stimulated neural apoptosis in an in vivo sevoflurane exposure model

Objective

Common inhalation anesthetics used for clinical anesthesia (such as sevoflurane) may induce nerve cell apoptosis during central nervous system development. Furthermore, anesthetics can produce cognitive impairments, such as learning and memory impairments, that continue into adulthood. However, the precise mechanism remains largely undefined. We aimed to determine the function of microRNA-1297 (miR-1297) in sevoflurane-induced neurotoxicity.

Methods

Reverse transcription-polymerase chain reaction assays were used to analyze miR-1297 expression in sevoflurane-exposed mice. MTT and lactate dehydrogenase (LDH) assays were used to measure cell growth, and neuronal apoptosis was analyzed using flow cytometry. Western blot analyses were used to measure PTEN, PI3K, Akt, and GSK3β protein expression.

Results

In sevoflurane-exposed mice, miR-1297 expression was up-regulated compared with the control group. MiR-1297 up-regulation led to neuronal apoptosis, inhibition of cell proliferation, and increased LDH activity in the in vitro model of sevoflurane exposure. MiR-1297 up-regulation also suppressed the Akt/GSK3β signaling pathway and induced PTEN protein expression in the in vitro model. PTEN inhibition (VO-Ohpic trihydrate) reduced PTEN protein expression and decreased the effects of miR-1297 down-regulation on neuronal apoptosis in the in vitro model.

Conclusion

Collectively, the results indicated that miR-1297 stimulates sevoflurane-induced neurotoxicity via the Akt/GSK3β signaling pathway by regulating PTEN expression.

AMPK and its Activator Berberine in the Treatment of Neurodegenerative Diseases

Neurodegenerative disorders are heterogeneous diseases associated with either acute or progressive neurodegeneration, causing the loss of neurons and axons in the central nervous system (CNS), showing high morbidity and mortality, and there are only a few effective therapies. Here, we summarized that the energy sensor adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), and its agonist berberine can combat the common underlying pathological events of neurodegeneration, including oxidative stress, neuroinflammation, mitochondrial disorder, glutamate excitotoxicity, apoptosis, autophagy disorder, and disruption of neurovascular units. The abovementioned effects of berberine may primarily depend on activating AMPK and its downstream targets, such as the mammalian target of rapamycin (mTOR), sirtuin1 (SIRT1), nuclear factor erythroid-2 related factor-2 (Nrf2), nuclear factor-κB (NF-κB), phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), nicotinamide adenine dinucleotide (NAD+), and p38 mitogen-activated protein kinase (p38 MAPK). It is hoped that this review will provide a strong basis for further scientific exploration and development of berberine's therapeutic potential against neurodegeneration.

Role of natural plant products against Alzheimer's disease

Alzheimer's disease (AD) is one of the major neurodegenerative disorder. Deposition of amyloid fibrils and tau protein are associated with various pathological symptoms. Currently limited medication is available for AD treatment. Most of the drugs are basically cholinesterase inhibitors and associated with various side effects. Natural plant products have shown potential as a therapeutic agent for the treatment of AD symptoms. Variety of secondary metabolites like flavonoids, tannins, terpenoids, alkaloids and phenols are used to reduce the progression of the disease. Plant products have less or no side effect and are easily available. The present review gives a detailed account of the potential of natural plant products against the AD symptoms.

PI3K/AKT Signal Pathway: A Target of Natural Products in the Prevention and Treatment of Alzheimer's Disease and Parkinson's Disease

Alzheimer’s disease (AD) and Parkinson’s disease (PD) are two typical neurodegenerative diseases that increased with aging. With the emergence of aging population, the health problem and economic burden caused by the two diseases also increase. Phosphatidylinositol 3-kinases/protein kinase B (PI3K/AKT) signaling pathway regulates signal transduction and biological processes such as cell proliferation, apoptosis and metabolism. According to reports, it regulates neurotoxicity and mediates the survival of neurons through different substrates such as forkhead box protein Os (FoxOs), glycogen synthase kinase-3β (GSK-3β), and caspase-9. Accumulating evidences indicate that some natural products can play a neuroprotective role by activating PI3K/AKT pathway, providing an effective resource for the discovery of potential therapeutic drugs. This article reviews the relationship between AKT signaling pathway and AD and PD, and discusses the potential natural products based on the PI3K/AKT signaling pathway to treat two diseases in recent years, hoping to provide guidance and reference for this field. Further development of Chinese herbal medicine is needed to treat these two diseases.

Costunolide attenuates oxygen‑glucose deprivation/reperfusion‑induced mitochondrial‑mediated apoptosis in PC12 cells

The present study investigated the effect of costunolide (CT), a compound extracted from Aucklandia lappa Decne, to attenuate oxygen-glucose deprivation/reperfusion (OGD/R)-induced mitochondrial-mediated apoptosis in PC12 cells. The present study used molecular docking technology to detect the binding of CT with mitochondrial apoptotic protein targets. A model of oxygen-glucose deprivation for 2 h and reperfusion for 24 h in PC12 cells was used to mimic cerebral ischemic injury. Cell viability and damage were measured using the Cell Counting kit-8 and lactate dehydrogenase (LDH) cytotoxicity assay kits. Cellular apoptosis was analyzed using flow cytometry. A fluorescence microscope determined intracellular [Ca²⁺] and mitochondrial membrane potential. Furthermore, immunofluorescence and Western blot analyses were used to detect the expression of apoptosis-associated proteins. CT contains binding sites with Caspase-3, Caspase-9 and Caspase-7. CT markedly enhanced cell viability, inhibited LDH leakage, increased intracellular [Ca²⁺], stabilized the mitochondrial membrane potential, increased the expression of Bcl-2 and inhibited the expression of Apaf-1, Bax, cleaved-caspase-7, cleaved-caspase-9 and cleaved-caspase-3. CT may markedly protect PC12 cells from damage caused by OGD/R, and its mechanism is associated with blocking the calcium channel and inhibiting mitochondrial-mediated apoptosis.

IDO-1 inhibition protects against neuroinflammation, oxidative stress and mitochondrial dysfunction in 6-OHDA induced murine model of Parkinson's disease

Parkinson's disease (PD), a common neurodegenerative motor disorder characterized by striatal dopaminergic neuronal loss and localized neuroinflammation in the midbrain region. Activation of microglia is associated with various inflammatory mediators and Kynurenine pathway (KP) being one of the major regulator of immune response, is involved in the neuroinflammatory and neurotoxic cascade in PD. In the current study, 1-Methyltryptophan (1-MT), an Indolamine-2,3-dioxygenase-1 (IDO-1) inhibitor was tested at different doses (2.5 mg/kg, 5 mg/kg and 10 mg/kg) for its effect on behavioral parameters, oxidative stress, neuroinflammation, apoptosis, mitochondrial dysfunction, neurotransmitter levels, biochemical and behavioral alterations in unilateral 6-OHDA (3 μg/μL) murine model of PD. The results showed improved locomotion in open field test and motor coordination in rota-rod, reduced oxidative stress, neuroinflammatory markers (TNF-α, IFN-γ, IL-6), mitochondrial dysfunction and neuronal apoptosis (caspase-3). Also, restoration of neurotransmitter levels (dopamine and homovanillic acid) in the striatum and increased striatal BDNF levels were observed. Overall findings suggest that 1-MT could be a potential candidate for further studies to explore its possibility as an alternative in the pharmacotherapy of PD.