Berberine Improves Cognitive Impairment by Simultaneously Impacting Cerebral Blood Flow and β-Amyloid Accumulation in an APP/tau/PS1 Mouse Model of Alzheimer's Disease

Research progress on pharmacological effects and bioavailability of berberine

Berberine (BBR), a benzylisoquinoline alkaloid obtained from natural medicines such as coptidis rhizoma, has a wide range of pharmacological activities such as protecting the nervous system, protecting the cardiovascular system, anti-inflammatory, antidiabetic, antihyperlipidemic, antitumor, antibacterial, and antidiarrheal. However, factors such as poor solubility, low permeability, P-glycoprotein (P-gp) efflux, and hepatic-intestinal metabolism result in BBR having a low bioavailability (< 1%), which restricts its application in clinical settings. Therefore, improving its bioavailability is a prerequisite for its clinical applications. This review summarizes the various pharmacological effects of BBR and analyzes the main reasons for its poor bioavailability. It introduces methods to improve the bioavailability of BBR through the use of absorption enhancers and P-gp inhibitors, structural modification of BBR, and preparation of BBR salts and cocrystals as well as the development of new formulations and focuses on the bioavailability study of the new formulations of BBR. The research of BBR was also prospected in order to provide reference for the further research of BBR.

Minocycline as a prospective therapeutic agent for cancer and non-cancer diseases: a scoping review

Minocycline is an FDA-approved secondary-generation tetracycline antibiotic. It is a synthetic antibiotic having many biological effects, such as antioxidant, anti-inflammatory, anti-cancer, and neuroprotective functions. This study discusses the pharmacological mechanisms of preventive and therapeutic effects of minocycline. Specifically, it provides a comprehensive overview of the molecular pathways by which minocycline acts on the different cancers, including ovarian, breast, glioma, colorectal, liver, pancreatic, lung, prostate, melanoma, head and neck, leukemia, and non-cancer diseases such as Alzheimer's disease, Parkinson, schizophrenia, multiple sclerosis, Huntington, polycystic ovary syndrome, and coronavirus disease 19. Minocycline may be a potential medication for these disorders due to its strong blood-brain barrier penetrance. It is also widely accepted as a specific medication, has a well-known side-effect characteristic, is reasonably priced, making it appropriate for continuous use in managing diseases, and has been demonstrated as an oral approach because it is effectively absorbed and accomplished almost all of the body's parts.

Therapeutic effects of long-term HBOT on Alzheimer's disease neuropathologies and cognitive impairment in APPswe/PS1dE9 mice

Alzheimer's disease (AD) is the most common neurodegenerative disorder with the pathological hallmarks of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) in the brain. Although there is a hope that anti-amyloid monoclonal antibodies may emerge as a new therapy for AD, the high cost and side effect is a big concern. Non-drug therapy is attracting more attention and may provide a better resolution for the treatment of AD. Given the fact that hypoxia contributes to the pathogenesis of AD, hyperbaric oxygen therapy (HBOT) may be an effective intervention that can alleviate hypoxia and improve AD. However, it remains unclear whether long-term HBOT intervention in the early stage of AD can slow AD progression and ultimately prevent cognitive impairment in this disease. In this study we applied consecutive 3-month HBOT interventions on 3-month-old APPswe/PS1dE9 AD mice which represent the early stage of AD. When the APPswe/PS1dE9 mice at 9-month-old which represent the disease stage we measured cognitive function, 24-h blood oxygen saturation, Aβ and tau pathologies, vascular structure and function, and neuroinflammation in APPswe/PS1dE9 mice. Our results showed that long-term HBOT can attenuate the impairments in cognitive function observed in 9-month-old APPswe/PS1dE9 mice. Most importantly, HBOT effectively reduced the progression of Aβ plaques deposition, hyperphosphorylated tau protein aggregation, and neuronal and synaptic degeneration in the AD mice. Further, long-term HBOT was able to enhance blood oxygen saturation level. Besides, long-term HBOT can improve vascular structure and function, and reduce neuroinflammation in AD mice. This study is the first to demonstrate that long-term HBOT intervention in the early stage of AD can attenuate cognitive impairment and AD-like pathologies. Overall, these findings highlight the potential of long-term HBOT as a disease-modifying approach for AD treatment.

A network pharmacology method explores the molecular mechanism of Coptis chinensis for the treatment of Alzheimer's disease

To predict the molecular mechanisms of action of Coptis chinensis in the treatment of Alzheimer's disease using network pharmacology. The active ingredients and targets of Coptis chinensis were obtained from the Traditional Chinese Medicine System Pharmacology Database. Target information for Alzheimer's disease was screened using the GeneCard and OMIM databases. The Venn diagram tool was used to identify the intersecting targets of Coptis chinensis and Alzheimer's disease. The obtained target information was entered into the STRING database to construct a protein-protein interaction network. The R language was used to perform Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses of significant targets. Auto Dock Vina software was used for molecular docking. Fourteen effective active ingredients and 158 key targets associated with Coptis chinensis were identified. There were 1113 targets related to Alzheimer's disease genes. A drug-component-disease-target network was constructed and 84 key targets were identified for the treatment of Alzheimer's disease by Coptis chinensis. The main signaling pathways were the PI3K-Akt, AGE-RAGE, MAPK, HIF-1, TNF, and relaxin signaling pathways. The molecular docking results showed that berberine has a high affinity for Alzheimer's Disease. Coptis chinensis could play a multi-target and multi-pathway role against Alzheimer's disease, which has guiding significance for clinical research.

NIR Plasmonic Nanozymes: Synergistic Enhancement Mechanism and Multi-Modal Anti-Infection Applications of MXene/MOFs

Nanozymes are considered as the promising antimicrobial agents due to the enzyme-like activity for chemo-dynamic therapy (CDT). However, it remains a challenge to develop novel nanozyme systems for achieving stimuli-responsive, and efficient nanozyme catalysis with multimodal synergistic enhancement. In this work, a near-infrared (NIR) plasmonic-enhanced nanozyme catalysis and photothermal performance for effective antimicrobial applications are proposed. A Ti3 C2 MXene/Fe-MOFs composite (MXM) with NIR plasmonic-enhanced CDT combined with photothermal properties is successfully developed by loading metal-organic framework (MOF) nanozymes onto Ti3 C2 MXene. The mechanism of NIR induced localized surface plasmon resonance (LSPR)-enhanced CDT and photothermal therapy (PTT) is well explained through activation energy (Ea ), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), fluorescence analysis experiments, and finite element simulation. It reveals that MXene nanosheets exhibit NIR plasmon exciters and generate hot electrons that can transfer to the surface of Fe-MOFs, promoting the Fenton reaction and enhances CDT. While the photothermal heating of MXene produced by LSPR can also boost the CDT of Fe-MOFs under NIR irradiation. Both in vitro and in vivo experimental results demonstrate that LSPR-induced MXM system has outstanding antimicrobial properties, can promote angiogenesis and collagen deposition, leading to the accelerated wound healing.

Neuroprotective effects and possible mechanisms of berberine in animal models of Alzheimer's disease: a systematic review and meta-analysis

Background: Recently, multiple preclinical studies have reported the beneficial effect of berberine in the treatment of Alzheimer's disease (AD). Nevertheless, the neuroprotective effects and possible mechanisms of berberine against AD are not universally recognized. This study aimed to conduct a systematic review and meta-analysis by integrating relevant animal studies to assess the neuroprotective effects and potential mechanisms of berberine on AD. Methods: We systematically searched PubMed, Embase, Scopus and Web of Science databases that reported the effects of berberine on AD models up to 1 February 2023. The escape latency, times of crossing platform, time spent in the target quadrant and pro-oligomerized amyloid beta 42 (Aβ1-42) were included as primary outcomes. The secondary outcomes were the Tau-ps 204, Tau-ps 404, β-site of APP cleaving enzyme (BACE1), amyloid precursor protein (APP), acetylcholine esterase (AChE), tumor necrosis factor ⍺ (TNF-α), interleukin 1β (IL-1β), IL-6, nitric oxide (NO), glial fibrillary acidic protein (GFAP), malonaldehyde (MDA), glutathione S-transferase (GST), glutathione (GSH), glutathione peroxidase (GPx), Beclin-1 and neuronal apoptosis cells. This meta-analysis was conducted using RevMan 5.4 and STATA 15.1. The SYRCLE's risk of bias tool was used to assess the methodological quality. Results: Twenty-two studies and 453 animals were included in the analysis. The overall results showed that berberine significantly shortened the escape latency (p < 0.00001), increased times of crossing platform (p < 0.00001) and time spent in the target quadrant (p < 0.00001), decreased Aβ1-42 deposition (p < 0.00001), Tau-ps 202 (p < 0.00001) and Tau-ps 404 (p = 0.002), and improved BACE1, APP, AChE, Beclin-1, neuronal apoptosis cells, oxidative stress and inflammation levels. Conclusion: Berberine may be a promising drug for the treatment of AD based on preclinical evidence (especially when the dose was 5-260 mg/kg). The potential mechanisms for these protective effects may be closely related to anti-neuroinflammation, anti-oxidative stress, modulation of autophagy, inhibition of neuronal apoptosis and protection of cholinergic system. However, these results may be limited by the quality of existing research. Larger and methodologically more rigorous preclinical research are needed to provide more convincing evidence.

Effects of new hypnotic drugs on cognition: A systematic review and network meta-analysis

Background

Insomnia is a common disease, and the application of various types of sleeping pills for cognitive impairment is controversial, especially as different doses can lead to different effects. Therefore, it is necessary to evaluate the cognitive impairment caused by different sleeping pills to provide a theoretical basis for guiding clinicians in the selection of medication regimens.

Objective

To evaluate whether various different doses (low, medium and high) of anti-insomnia drugs, such as the dual-orexin receptor antagonist (DORA), zopiclone, eszopiclone and zolpidem, induce cognitive impairment.

Methods

The PubMed, Embase, Scopus, Cochrane Library, and Google Scholar databases were searched from inception to September 20th, 2022 for keywords in randomized controlled trials (RCTs) to evaluate the therapeutic effects of DORA, eszopiclone, zopiclone and zolpidem on sleep and cognitive function. The primary outcomes were indicators related to cognitive characteristics, including scores on the Digit Symbol Substitution Test (DSST) and daytime alertness. The secondary outcomes were the indicators associated with sleep and adverse events. Continuous variables were expressed as the standard mean difference (SMD). Data were obtained through GetData 2.26 and analyzed by Stata v.15.0.

Results

A total of 8702 subjects were included in 29 studies. Eszopiclonehigh significantly increased the daytime alertness score (SMD = 3.00, 95 % CI: 1.86 to 4.13) compared with the placebo, and eszopiclonehigh significantly increased the daytime alertness score (SMD = 4.21, 95 % CI: 1.65 to 6.77; SMD = 3.95, 95 % CI: 1.38 to 6.51; SMD = 3.26, 95 % CI: 0.38 to 6.15; and SMD = 3.23, 95 % CI: 0.34 to 6.11) compared with zolpidemlow, zolpidemhigh, DORAlow, and eszopiclonemid, respectively. Compared with the placebo, zopiclone, zolpidemmid, and eszopiclonehigh, DORA significantly increased the TST (SMD = 2.39, 95 % CI: 1.11 to 3.67; SMD = 6.00, 95 % CI: 2.73 to 9.27; SMD = 1.89, 95 % CI: 0.90 to 2.88; and SMD = 1.70, 95 % CI: 0.42 to 2.99, respectively).

Conclusion

We recommend DORA as the best intervention for insomnia because it was highly effective in inducing and maintaining sleep without impairing cognition. Although zolpidem had a more pronounced effect on sleep maintenance, this drug is better for short-term use. Eszopiclone and zopiclone improved sleep, but their cognitive effects have yet to be verified.

Network pharmacology and in vivo studies reveal the neuroprotective effects of paeoniflorin on Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease that has still not been effectively treated. Paeoniflorin is a traditional Chinese medicine with potential neuroprotective effects against brain injury; however, the beneficial effects and mechanisms of action in AD have not been clarified. We aimed to explore the mechanisms of action of paeoniflorin in AD using network pharmacology and experimental validation. Network pharmacology analysis revealed 30 candidate targets through the intersection of the targets of paeoniflorin and related genes in AD, which were mainly enriched in oxidative stress and inflammation. Moreover, key targets of paeoniflorin against AD, namely Nrf2 (encoded by NFE2L2) and TLR4, were screened and found to be closely related to oxidative stress and inflammation. Subsequent in vivo experiments revealed that paeoniflorin treatment improved the cognition of APP/PS1 mice by ameliorating oxidative stress and neuroinflammation, which were associated with the upregulation of Nrf2 and HO1, and the downregulation of TLR4. Collectively, the present study demonstrates that paeoniflorin alleviates cognitive impairment in AD by regulating oxidative stress and neuroinflammation, and that Nrf2, HO1, and TLR4 could be key targets.

The composition, pharmacological effects, related mechanisms and drug delivery of alkaloids from Corydalis yanhusuo

Corydalis yanhusuo W. T. Wang, also known as yanhusuo, yuanhu, yanhu and xuanhu, is one of the herb components of many Chinese Traditional Medicine prescriptions such as Jin Ling Zi San and Yuanhu-Zhitong priscription. C. yanhusuo was traditionally used to relieve pain and motivate blood and Qi circulation. Now there has been growing interest in pharmacological effects of alkaloids, the main bioactive components of C. yanhusuo. Eighty-four alkaloids isolated from C. yanhusuo are its important bioactive components and can be characterized into protoberberine alkaloids, aporphine alkaloids, opiate alkaloids and others and proper extraction or co-administration methods modulate their contents and efficacy. Alkaloids from C. yanhusuo have various pharmacological effects on the nervous system, cardiovascular system, cancer and others through multiple molecular mechanisms such as modulating neurotransmitters, ion channels, gut microbiota, HPA axis and signaling pathways and are potential treatments for many diseases. Plenty of novel drug delivery methods such as autologous red blood cells, self-microemulsifying drug delivery systems, nanoparticles and others have also been investigated to better exert the effects of alkaloids from C. yanhusuo. This review summarized the alkaloid components of C. yanhusuo, their pharmacological effects and mechanisms, and methods of drug delivery to lay a foundation for future investigations.

Age-related decline in hippocampal tyrosine phosphatase PTPRO is a mechanistic factor in chemotherapy-related cognitive impairment

Chemotherapy-related cognitive impairment (CRCI) or "chemo brain" is a devastating neurotoxic sequela of cancer-related treatments, especially for the elderly individuals. Here we show that PTPRO, a tyrosine phosphatase, is highly enriched in the hippocampus, and its level is tightly associated with neurocognitive function but declined significantly during aging. To understand the protective role of PTPRO in CRCI, a mouse model was generated by treating Ptpro-/- female mice with doxorubicin (DOX) because Ptpro-/- female mice are more vulnerable to DOX, showing cognitive impairments and neurodegeneration. By analyzing PTPRO substrates that are neurocognition-associated tyrosine kinases, we found that SRC and EPHA4 are highly phosphorylated/activated in the hippocampi of Ptpro-/- female mice, with increased sensitivity to DOX-induced CRCI. On the other hand, restoration of PTPRO in the hippocampal CA3 region significantly ameliorate CRCI in Ptpro-/- female mice. In addition, we found that the plant alkaloid berberine (BBR) is capable of ameliorating CRCI in aged female mice by upregulating hippocampal PTPRO. Mechanistically, BBR upregulates PTPRO by downregulating miR-25-3p, which directly targeted PTPRO. These findings collectively demonstrate the protective role of hippocampal PTPRO against CRCI.

Berberine ameliorates iron levels and ferroptosis in the brain of 3 × Tg-AD mice

BACKGROUND

Berberine (BBR) is a natural alkaloid extracted from the herb Coptis chinensis. This compound has the ability to penetrate the blood-brain barrier (BBB) and exhibit neuroprotective value in the treatment of Alzheimer's disease (AD). AD is a neurodegenerative disease characterized by β-amyloid (Aβ) deposition, hyperphosphorylated tau and other characters. Iron accumulation and ferroptosis were also detected in AD brain, which can result in neuronal damage. However, it is still unclear whether BBR can suppress ferroptosis in AD and alleviate its underlying pathology.

PURPOSE

This study investigated whether BBR may affect ferroptosis and related signaling pathways in triple transgenic AD (3 × Tg-AD) mice.

METHODS

Four-month-old 3 × Tg-AD mice received oral administration of BBR at a dose of 50 mg/kg for 7.5 months. Cognitive function and anxiety levels in mice were assessed using the morris water maze test, open field test, and novel object recognition test. Western blot, immunohistochemistry, and ICP-MS were employed to assess the pathology of AD, brain iron metabolism, and ferroptosis signaling pathways. Transmission electron microscopy was used to detect mitochondrial changes. The synergistic effects of BBR combined with Nrf2 were investigated using molecular docking programs and surface plasmon resonance technology. Co-inmunoprecipitation assay was used to examine the effect of BBR on the binding ability of Nrf2 and Keap1.

RESULTS

The results indicated that chronic treatment of BBR mitigated cognitive disorders in 3 × Tg-AD model mice. Reductions in Aβ plaque, hyperphosphorylated tau protein, neuronal loss, and ferroptosis in the brains of 3 × Tg-AD mice suggested that BBR could alleviate brain injury. In addition, BBR treatment attenuated ferroptosis, as evidenced by decreased levels of iron, MDA, and ROS, while enhancing SOD, GSH, GPX4, and SLC7A11. Consistent with the in vivo assay, BBR inhibited RSL3-induced ferroptosis in N2a-sw cells. BBR increased the expression levels of GPX4, FPN1 and SLC7A11 by regulating Nrf2 transcription levels, thereby inhibiting ferroptosis. Molecular docking programs and surface plasmon resonance technology demonstrated the direct combination of BBR with Nrf2. Co-inmunoprecipitation analysis showed that BBR inhibited the interaction between Keap1 and Nrf2.

CONCLUSION

For the first time, these results showed that BBR could inhibit iron levels and ferroptosis in the brains of 3 × Tg-AD model mice and partially protect against RSL3-induced ferroptosis via the activation of Nrf2 signaling.

Network pharmacology reveals that Berberine may function against Alzheimer's disease via the AKT signaling pathway

Objective

To investigate the mechanism underlying the effects of berberine (BBR) in the treatment of Alzheimer's disease (AD).

Methods

3 × Tg AD mice were treated with BBR for 3 months, then the open field test (OFT), the novel object recognition test (NOR) and the Morris water maze (MWM) test were performed to assess behavioral performance. Hematoxylin-eosin (HE) staining, Nissl staining were used to examine histopathological changes. The pharmacological and molecular properties of BBR were obtained from the TCMSP database. BBR-associated AD targets were identified using the PharmMapper (PM), the comparative toxicogenomics database (CTD), DisGeNet and the human gene database (GeneCards). Core networks and BBR targets for the treatment of AD were identified using PPI network and functional enrichment analyses. AutoDock software was used to model the interaction between BBR and potential targets. Finally, RT-qPCR, western blotting were used to validate the expression of core targets.

Results

Behavioral experiments, HE staining and Nissl staining have shown that BBR can improve memory task performance and neuronal damage in the hippocampus of AD mice. 117 BBR-associated targets for the treatment of AD were identified, and 43 genes were used for downstream functional enrichment analysis in combination with the results of protein-protein interaction (PPI) network analysis. 2,230 biological processes (BP) terms, 67 cell components (CC) terms, 243 molecular function (MF) terms and 118 KEGG terms were identified. ALB, EGFR, CASP3 and five targets in the PI3K-AKT signaling pathway including AKT1, HSP90AA1, SRC, HRAS, IGF1 were selected by PPI network analysis, validated by molecular docking analysis and RT-q PCR as core targets for further analysis. Akt1 mRNA expression levels were significantly decreased in AD mice and significantly increased after BBR treatment (p < 0.05). Besides, AKT and ERK phosphorylation decreased in the model group, and BBR significantly increased their phosphorylation levels.

Conclusion

AKT1, HSP90AA1, SRC, HRAS, IGF1 and ALB, EGFR, CASP3 were core targets of BBR in the treatment of AD. BBR may exert a neuroprotective effect by modulating the ERK and AKT signaling pathways.

Astrocytes-derived exosomes pre-treated by berberine inhibit neuroinflammation after stroke via miR-182-5p/Rac1 pathway

BACKGROUND

Our previous studies have shown that berberine can improve the nerve function deficits in ischemic stroke by inhibiting inflammation. The cellular communication between astrocytes and neurons via exosomes might affect neurological function after ischemic stroke, which plays a vital role in the therapy of ischemic stroke.

OBJECTIVE

The present study focused on the effects of exosomes released from astrocytes induced by the glucose and oxygen deprivation model with berberine pretreatment (BBR-exos) treatment for ischemic stroke and its regulatory mechanism.

METHODS

Oxygen-glucose-deprivation/Reoxygenation (OGD/R)-treated primary cells were used to mimic cerebral ischemia/reperfusion conditions in vitro. With the treatment of BBR-exos and exosomes released from primary astrocytes induced by the glucose and oxygen deprivation model (OGD/R-exos), the cell viability was detected. C57BL/6J mice were used to establish middle cerebral artery occlusion/reperfusion (MCAO/R) model. The anti-neuroinflammation effects of BBR-exos and OGD/R-exos were evaluated. Subsequently, the key miRNA in BBR-exos was identified by exosomal miRNA sequencing and cell validation. miR-182-5p mimic and inhibitors were provided to verify the effects in inflammation. Finally, the binding sites between miR-182-5p and Rac1 were predicted online and verified by using a dual-luciferase reporter assay.

RESULTS

BBR-exos and OGD/R-exos both improved the decreased activity of OGD/R-induced neurons, and decreased the expression of IL-1β, IL-6 and TNF-α (all P ＜ 0.05), which reduced neuronal injury and inhibited neuroinflammation in Vitro. And BBR-exos showed better effects (P ＜ 0.05). The same effect has been verified in vivo experiments: BBR-exos and OGD/R-exos both reduced cerebral ischemic injury and inhibited neuroinflammation in MCAO/R mice (all P ＜ 0.05). Likewise, BBR-exos showed better effects (P ＜ 0.05). The exosomal miRNA sequencing results showed that miR-182-5p was highly expressed in BBR-exos and inhibited neuroinflammation by targeting Rac1 (P ＜ 0.05).

CONCLUSION

BBR-exos can carry miR-182-5p to injured neurons and inhibit the expression of Rac1, which could inhibit neuroinflammation and improved brain injury after ischemic stroke.

Berberine improves negative symptoms and cognitive function in patients with chronic schizophrenia via anti-inflammatory effect: a randomized clinical trial

BACKGROUND

Based on the neuroinflammation hypothesis in schizophrenia and known anti-inflammatory effects of berberine, the aim of the present study is to investigate the efficacy of berberine in treating negative symptoms and cognitive deficits in adult patients with chronic schizophrenia.

METHODS

Enrolled participants were randomized to receive berberine or placebo for 3 months. The Scale for the Assessment of Negative Symptoms (SANS), Trail-making Test A (TMT-A), Trail-making Test B (TMT-B), and Hopkins Verbal Learning Test (HVLT) were used to evaluate the negative symptoms and cognitive function at four-time points (baseline, 1st, 2nd, and 3rd month). Serum levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were used as inflammatory markers. 106 patients with per-protocol were analyzed, 56 in the experimental (berberine) group and 50 in the control (placebo) group.

RESULTS

From baseline to month 3, patients receiving berberine demonstrated a decrease in total scores on clinical scales SANS, TMT-A and TMT-B and showed a serum level reduction of IL-1β, IL-6 and TNF-α comparing with patients in the control group (P < 0.05). There were positive correlations between the change of serum IL-1β level and the change of SANS (r = 0.210, P = 0.039), TMT-A (r = 0.522, P < 0.001), and TMT-B (r = 0.811, P < 0.001); between the change of serum IL-6 level and the change of TMT-A (r = 0.562, P < 0.001), and TMT-B (r = 0.664, P < 0.001); between the change of serum TNF-α level and the change of TMT-B (r = 0.472, P < 0.001) after berberine treatment.

CONCLUSIONS

Berberine is an anti-inflammatory agent that can potentially mitigate the negative symptoms and cognitive deficits in patients with schizophrenia.

Natural bioactive compounds in Alzheimer's disease: From the perspective of type 3 diabetes mellitus

There is a close relationship between Alzheimer's disease (AD) and diabetes mellitus (DM), and the link between the two is often referred to as type 3 diabetes mellitus (T3DM). Many natural bioactive compounds have shown the potential to treat AD and diabetes. We mainly review the polyphenols represented by resveratrol (RES) and proanthocyanidins (PCs) and alkaloids represented by berberine (BBR) and Dendrobium nobile Lindl. alkaloids (DNLA) from the perspective of T3DM to review the neuroprotective effects and molecular mechanisms of natural compounds in AD.

Natural Alkaloids as Multi-Target Compounds towards Factors Implicated in Alzheimer's Disease

Alzheimer's disease (AD) is the most common cause of dementia in elderly people; currently, there is no efficient treatment. Considering the increase in life expectancy worldwide AD rates are predicted to increase enormously, and thus the search for new AD drugs is urgently needed. A great amount of experimental and clinical evidence indicated that AD is a complex disorder characterized by widespread neurodegeneration of the CNS, with major involvement of the cholinergic system, causing progressive cognitive decline and dementia. The current treatment, based on the cholinergic hypothesis, is only symptomatic and mainly involves the restoration of acetylcholine (ACh) levels through the inhibition of acetylcholinesterase (AChE). Since the introduction of the Amaryllidaceae alkaloid galanthamine as an antidementia drug in 2001, alkaloids have been one of the most attractive groups for searching for new AD drugs. The present review aims to comprehensively summarize alkaloids of various origins as multi-target compounds for AD. From this point of view, the most promising compounds seem to be the β-carboline alkaloid harmine and several isoquinoline alkaloids since they can simultaneously inhibit several key enzymes of AD's pathophysiology. However, this topic remains open for further research on detailed mechanisms of action and the synthesis of potentially better semi-synthetic analogues.

The efficacy and mechanism of berberine in improving aging-related cognitive dysfunction: A study based on network pharmacology

Objective

To analyze the effects and mechanisms of berberine in the treatment of aging-related cognitive dysfunction based on network pharmacology methods, molecular docking techniques, and animal experiments.

Methods

A mouse model of cognitive dysfunction was constructed by subcutaneous injection of D-galactose (D-gal) for 10 weeks, and the neuroprotective effects of berberine on aging-related cognitive dysfunction mice were evaluated by the Morris water maze (MWM) and immunofluorescence staining. The targets of berberine were obtained by SwissTargetPrediction, GeneCards, and PharmMapper. Putative targets of cognitive dysfunction were obtained by GeneCards, TTD, and DrugBank database. The STRING database and Cytoscape software were applied for protein-protein interaction (PPI) analysis and further screening of core targets. The DAVID database was used for Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) enrichment analysis to clarify the biological processes and pathways involved in the intersection targets, and AutoDockTools was adopted for molecular docking verification of core targets. Finally, the core genes were validated using real-time quantitative PCR.

Results

The MWM results showed that treatment with berberine significantly improved spatial learning and memory in mice with cognitive decline induced by D-gal. Immunofluorescence staining indicated that berberine modified the levels of aging-related markers in the brain. A total of 386 berberine putative targets associated with cognitive dysfunction were identified based on the public database. The core targets of berberine for improving cognitive function, include Mapk1, Src, Ctnnb1, Akt1, Pik3ca, Tp53, Jun, and Hsp90aa1. GO enrichment and KEGG pathway enrichment analyses indicated that the mechanism of berberine in the treatment of aging-related cognitive dysfunction is attributed to pathways such as PI3K-AKT and MAPK pathways. In vivo experiments further confirmed that Akt1, Ctnnb1, Tp53, and Jun were involved in the neuroprotective actions of berberine.

Conclusion

This study reveals the multi-target and multi-pathway effects of berberine on regulating aging-related cognitive dysfunction, which provides preclinical evidence and may promote new drug development in mitigating cognitive dysfunction.

Comparison of Yizhiqingxin formula extraction methods and their pharmacodynamic differences

Objectives

This study compared different extraction methods of Yizhiqingxin formula (YQF) and its neuroprotective effects based on pharmacodynamic indices such as learning and memory ability, brain tissue histopathology and morphology, and inflammatory factor expression in a mouse model of Alzheimer's disease (AD).

Methods

The pharmaceutical components of YQF were extracted using three extraction processes, and the components were analyzed by high performance liquid chromatography. Donepezil hydrochloride was used as a positive control drug. Fifty 7-8-month-old 3 × Tg AD mice were randomly divided into three YQF groups (YQF-1, YQF-2, and YQF-3), a donepezil group, and a model group. Ten age-matched C57/BL6 mice were used as normal controls. YQF and Donepezil were administered by gavage at a clinically equivalent dose of 2.6 and 1.3 mg⋅kg^-1⋅d^-1, respectively, with a gavage volume of 0.1 ml/10 g. Control and model groups received equal volumes of distilled water by gavage. After 2 months, the efficacy was evaluated using behavioral experiments, histopathology, immunohistochemistry, and serum assays.

Results

The main components in YQF are ginsenoside Re, ginsenoside Rg1, ginsenoside Rb1, epiberberine, coptisine chloride, palmatine, berberine, and ferulic acid. YQF-3 (alcohol extraction) has the highest content of active compounds, followed by YQF-2 (water extraction and alcohol precipitation method). Compared to the model group, the three YQF groups showed alleviated histopathological changes and improved spatial learning and memory, with the effect in YQF-2 being the most significant. YQF showed protection of hippocampal neurons, most significantly in the YQF-1 group. YQF significantly reduced Aβ pathology and tau hyperphosphorylation, decreased expressions of serum pro-inflammatory factors interleukin-2 and interleukin-6 as well as serum chemokines MCP-1 and MIG.

Conclusion

YQF prepared by three different processes showed differences in pharmacodynamics in an AD mouse model. YQF-2 was significantly better than the other extraction processes in improving memory.

Current Insights on the Use of Insulin and the Potential Use of Insulin Mimetics in Targeting Insulin Signalling in Alzheimer's Disease

Alzheimer's disease (AD) and type 2 diabetes (T2D) are chronic diseases that share several pathological mechanisms, including insulin resistance and impaired insulin signalling. Their shared features have prompted the evaluation of the drugs used to manage diabetes for the treatment of AD. Insulin delivery itself has been utilized, with promising effects, in improving cognition and reducing AD related neuropathology. The most recent clinical trial involving intranasal insulin reported no slowing of cognitive decline; however, several factors may have impacted the trial outcomes. Long-acting and rapid-acting insulin analogues have also been evaluated within the context of AD with a lack of consistent outcomes. This narrative review provided insight into how targeting insulin signalling in the brain has potential as a therapeutic target for AD and provided a detailed update on the efficacy of insulin, its analogues and the outcomes of human clinical trials. We also discussed the current evidence that warrants the further investigation of the use of the mimetics of insulin for AD. These small molecules may provide a modifiable alternative to insulin, aiding in developing drugs that selectively target insulin signalling in the brain with the aim to attenuate cognitive dysfunction and AD pathologies.

Potential bioactive compounds and mechanisms of Fibraurea recisa Pierre for the treatment of Alzheimer's disease analyzed by network pharmacology and molecular docking prediction

Introduction

Heat-clearing and detoxifying Chinese medicines have been documented to have anti-Alzheimer's disease (AD) activities according to the accumulated clinical experience and pharmacological research results in recent decades. In this study, Fibraurea recisa Pierre (FRP), the classic type of Heat-clearing and detoxifying Chinese medicine, was selected as the object of research.

Methods

12 components with anti-AD activities were identified in FRP by a variety of methods, including silica gel column chromatography, multiple databases, and literature searches. Then, network pharmacology and molecular docking were adopted to systematically study the potential anti-AD mechanism of these compounds. Consequently, it was found that these 12 compounds could act on 235 anti-AD targets, of which AKT and other targets were the core targets. Meanwhile, among these 235 targets, 71 targets were identified to be significantly correlated with the pathology of amyloid beta (Aβ) and Tau.

Results and discussion

In view of the analysis results of the network of active ingredients and targets, it was observed that palmatine, berberine, and other alkaloids in FRP were the key active ingredients for the treatment of AD. Further, Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis revealed that the neuroactive ligand-receptor interaction pathway and PI3K-Akt signaling pathway were the most significant signaling pathways for FRP to play an anti-AD role. Findings in our study suggest that multiple primary active ingredients in FRP can play a multitarget anti-AD effect by regulating key physiological processes such as neurotransmitter transmission and anti-inflammation. Besides, key ingredients such as palmatine and berberine in FRP are expected to be excellent leading compounds of multitarget anti-AD drugs.

Research progress in traditional Chinese medicine in the treatment of Alzheimer's disease and related dementias

Alzheimer's disease (AD) is the world's leading cause of dementia and has become a huge economic burden on nations and families. However, the exact etiology of AD is still unknown, and there are no efficient medicines or methods to prevent the deterioration of cognition. Traditional Chinese medicine (TCM) has made important contributions in the battle against AD based on the characteristics of multiple targets of TCM. This study reviewed the treatment strategies and new discoveries of traditional Chinese medicine in current research, which may be beneficial to new drug researchers.

Vascular smooth muscle cell dysfunction in neurodegeneration

Vascular smooth muscle cells (VSMCs) are the key moderators of cerebrovascular dynamics in response to the brain's oxygen and nutrient demands. Crucially, VSMCs may provide a sensitive biomarker for neurodegenerative pathologies where vasculature is compromised. An increasing body of research suggests that VSMCs have remarkable plasticity and their pathophysiology may play a key role in the complex process of neurodegeneration. Furthermore, extrinsic risk factors, including environmental conditions and traumatic events can impact vascular function through changes in VSMC morphology. VSMC dysfunction can be characterised at the molecular level both preclinically, and clinically ex vivo. However the identification of VSMC dysfunction in living individuals is important to understand changes in vascular function at the onset and progression of neurological disorders such as dementia, Alzheimer's disease, and Parkinson's disease. A promising technique to identify changes in the state of cerebral smooth muscle is cerebrovascular reactivity (CVR) which reflects the intrinsic dynamic response of blood vessels in the brain to vasoactive stimuli in order to modulate regional cerebral blood flow (CBF). In this work, we review the role of VSMCs in the most common neurodegenerative disorders and identify physiological systems that may contribute to VSMC dysfunction. The evidence collected here identifies VSMC dysfunction as a strong candidate for novel therapeutics to combat the development and progression of neurodegeneration, and highlights the need for more research on the role of VSMCs and cerebrovascular dynamics in healthy and diseased states.

Berberine protects against chronic cerebral hypoperfusion-induced cognitive impairment and hippocampal damage via regulation of the ERK/Nrf2 pathway

Vascular cognitive impairment caused by chronic cerebral hypoperfusion (CCH) seriously affects the quality of life of elderly patients and places a great burden on society and family. With the development of traditional Chinese medicine (TCM), TCM approaches to the prevention and treatment of senile ischemic cerebrovascular disease has received increasing attention. In this study, rats with bilateral common carotid artery occlusion (BCCAO) were treated with berberine (BBR). Their learning and memory function, neuronal injury and repair, the extracellular regulatory protein kinase (ERK)/nuclear factor-E2-related factor 2 (Nrf2) signaling pathway, and impairment and improvement of the blood-brain barrier (BBB) were evaluated. This study found that BBR can alleviate the pathological injury to the brain, reduce neuronal loss and promote neuronal cell survival after CCH by interfering with the ERK/Nrf2 signaling pathway. BBR can reduce BBB injury in CCH rats by inhibiting the expression of VEGF-A and MMP-9 in plasma, which reveals a protective effect of BBR on vascular cognitive impairment. This study provides a new research direction for BBR in the treatment of ischemic cerebrovascular disease.

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.

Multiple Roles of Paeoniflorin in Alzheimer's Disease

Alzheimer's disease (AD) is a geriatric disease with the morbidity and mortality continuing to grow, partly due to the aging of the world population. As one of the most common types of primary neurodegenerative dementia, it is mainly due to environmental, epigenetic, immunological, and genetic factors. Paeoniflorin (PF), the main component of paeony extract, plays a more and more important role in the prevention and treatment of AD, including regulating protein, anti-inflammation, antioxidation, and antiapoptosis, protecting glial cells, regulating neurotransmitters and related enzymes and receptors, and inhibiting or activating related signal pathways. This article summarizes the latest researches on the multiple effects and the mechanisms of PF in the treatment to cure AD, providing new insights and research basis for further clinical application of traditional Chinese medicine (TCM) in the treatment of AD.

Berberine: A Review of its Pharmacokinetics Properties and Therapeutic Potentials in Diverse Vascular Diseases

Traditional Chinese medicine plays a significant role in the treatment of various diseases and has attracted increasing attention for clinical applications. Vascular diseases affecting vasculature in the heart, cerebrovascular disease, atherosclerosis, and diabetic complications have compromised quality of life for affected individuals and increase the burden on health care services. Berberine, a naturally occurring isoquinoline alkaloid form Rhizoma coptidis, is widely used in China as a folk medicine for its antibacterial and anti-inflammatory properties. Promisingly, an increasing number of studies have identified several cellular and molecular targets for berberine, indicating its potential as an alternative therapeutic strategy for vascular diseases, as well as providing novel evidence that supports the therapeutic potential of berberine to combat vascular diseases. The purpose of this review is to comprehensively and systematically describe the evidence for berberine as a therapeutic agent in vascular diseases, including its pharmacological effects, molecular mechanisms, and pharmacokinetics. According to data published so far, berberine shows remarkable anti-inflammatory, antioxidant, antiapoptotic, and antiautophagic activity via the regulation of multiple signaling pathways, including AMP-activated protein kinase (AMPK), nuclear factor κB (NF-κB), mitogen-activated protein kinase silent information regulator 1 (SIRT-1), hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), janus kinase 2 (JAK-2), Ca²⁺ channels, and endoplasmic reticulum stress. Moreover, we discuss the existing limitations of berberine in the treatment of vascular diseases, and give corresponding measures. In addition, we propose some research perspectives and challenges, and provide a solid evidence base from which further studies can excavate novel effective drugs from Chinese medicine monomers.

Secoyanhusamine A, an Oxidatively Ring-Opened Isoquinoline Inner Salt From Corydalis yanhusuo

Secoyanhusamine A (1), a rare rearranged seco-isoquinoline alkaloid derived from ring oxidative cleavage, was isolated from an aqueous extract of Corydalis yanhusuo tubers, together with its biosynthetic precursor dehydrocorybulbine (2). Secoyanhusamine A (1) was the first example of a highly oxidized isoquinoline inner salt resulting in a 5-(2-azanylethyl)-2-carboxylate-4-oxo-4H-pyran ring system. The biosynthetic pathway of 1 was also postulated. Secoyanhusamine A (1) exhibited potent inhibition against acetylcholinesterase (AChE) with an IC50 value of 0.81 ± 0.13 μM. Molecular simulation docking demonstrated that 1 created a strong interaction with the Asp-74 residue of AChE via attractive charge of the quaternary nitrogen.