Disease-Modifying Activity of Huperzine A on Alzheimer's Disease: Evidence from Preclinical Studies on Rodent Models.

(1) Background: Huperzine A, a natural cholinesterase (AChE) inhibitor isolated from the Chinese herb Huperzia Serrata, has been used as a dietary supplement in the United States and a drug in China for therapeutic intervention on Alzheimer's disease (AD). This review aims to determine whether Huperzine A exerts disease-modifying activity through systematic analysis of preclinical studies on rodent AD models. (2) Methods: Sixteen preclinical studies were included based on specific criteria, and the methodological qualities were analyzed by SYRCLE's risk of bias tool. Some outcomes were meta-analyzed: latencies and time spent in quadrant of Morris water maze, soluble amyloid-ß (Aß) level measured by ELISA in the cortex and hippocampus, Aß plaque numbers measured by immunohistochemistry in hippocampus, choline acetyltransferase (ChAT) activity, and AChE activity. Finally, the mechanisms of Huperzine A on AD models were summarized. (3) Conclusions: The outcomes showed that Huperzine A displayed AChE inhibition, ChAT activity enhancement, memory improvement, and Aß decreasing activity, indicating the disease-modifying effect of Huperzine A. However, due to the uneven methodological quality, the results need to be rationally viewed, and extensively repeated.

The effect of integrated health care in patients with hypertension and diabetes: a systematic review and meta-analysis.

BACKGROUND: A growing number of studies show that integrated health care provides comprehensive and continuous care to patients with hypertension or diabetes. However, there is still no consensus about the effect of integrated health care on patients with hypertension or diabetes. The objective of this study was to verify the effectiveness of integrated health care for patients with hypertension or diabetes by using a systematic review and meta-analysis. METHODS: The study searched multiple English and Chinese electronic databases. The search period was from database inception to 31 October 2020. Systematic reviews and meta-analyses were conducted after assessing the risk of bias of each study. RESULTS: Sixteen studies that involved 5231 patients were included in this study. The results of the systematic review revealed that systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI) and glycosylated haemoglobin (HbA1c) are commonly used indicators for patients with hypertension or diabetes. Individual models and group- and disease-specific models are the most commonly used models of integrated health care. All the studies were from high-income and middle-income countries. Meta-analysis showed that integrated health care significantly improved SBP, DBP and HbA1c but not BMI. A comparison of interventions lasting 6 and 12 months for diabetes was conducted, and HbA1c was decreased after 12 months. The changes in SBP and DBP were statistically significant after using group- and disease-specific model but not individual models. HbA1c was significantly improved after using group- and disease-specific models and individual models. CONCLUSION: Integrated health care is a useful tool for disease management, and individual models and group- and disease-specific models are the most commonly used models in integrated health care. Group- and disease-specific models are more effective than individual models in the disease management of hypertension patients. The duration of intervention should be considered in the disease management of patients with diabetes, and interventions longer than 12 months are recommended. The income level may affect the model of integrated health care in selecting which disease to intervene, but this point still needs support from more studies.

α-mangostin derivative 4e as a PDE4 inhibitor promote proteasomal degradation of alpha-synuclein in Parkinson's disease models through PKA activation.

BACKGROUND: Parkinson's disease (PD) is a multi-factorial neurodegenerative disease affecting motor function of patients. The hall markers of PD are dopaminergic neuron loss in the midbrain and the presence of intra-neuronal inclusion bodies mainly composed of aggregation-prone protein alpha-synuclein (α-syn). Ubiquitin-proteasome system (UPS) is a multi-step reaction process responsible for more than 80% intracellular protein degradation. Impairment of UPS function has been observed in the brain tissue of PD patients. PDE4 inhibitors have been shown to activate cAMP-PKA pathway and promote UPS activity in Alzheimer's disease model. α-mangostin is a natural xanthonoid with broad biological activities, such as antioxidant, antimicrobial and antitumour activities. Structure-based optimizations based on α-mangostin produced a potent PDE4 inhibitor, 4e. Herein, we studied whether 4e could promote proteasomal degradation of α-syn in Parkinson's disease models through PKA activation. METHODS: cAMP Assay was conducted to quantify cAMP levels in samples. Model UPS substrates (Ub-G76V-GFP and Ub-R-GFP) were used to monitor UPS-dependent activity. Proteasome activity was investigated by short peptide substrate, Suc-LLVY-AMC, cleavage of which by the proteasome increases fluorescence sensitivity. Tet-on WT, A30P, and A53T α-syn-inducible PC12 cells and primary mouse cortical neurons from A53T transgenic mice were used to evaluate the effect of 4e against α-syn in vitro. Heterozygous A53T transgenic mice were employed to assess the effect of 4e on the clearance of α-syn in vivo, and further validations were applied by western blotting and immunohistochemistry. RESULTS: Taken together, α-mangostin derivative 4e, a PDE4 inhibitor, efficiently activated the cAMP/PKA pathway in neuronal cells, and promoted UPS activity as evidenced by enhanced degradation of UPS substrate Ub-G76V-GFP and Ub-R-GFP, as well as elevated proteasomal enzyme activity. Interestingly, 4e dramatically accelerated degradation of inducibly-expressed WT and mutant α-syn in PC12 cells, in a UPS dependent manner. Besides, 4e consistently activated PKA in primary neuron and A53T mice brain, restored UPS inhibition and alleviated α-syn accumulation in the A53T mice brain. CONCLUSIONS: 4e is a natural compound derived highly potent PDE4 inhibitor. We revealed its potential effect in promoting UPS activity to degrade pathogenic proteins associated with PD.

Can We Use Ginkgo biloba Extract to Treat Alzheimer's Disease? Lessons from Preclinical and Clinical Studies.

(1) Background: Ginkgo biloba extract (GBE) has been widely used to treat central nervous system and cardiovascular diseases. Accumulating evidence has revealed the therapeutic potential of GBE against Alzheimer's disease (AD); however, no systematic evaluation has been performed; (2) Methods: a total of 17 preclinical studies and 20 clinical trials assessing the therapeutic effects of GBE against AD were identified from electronic databases. The data in the reports were extracted to conduct a meta-analysis of the AD-related pathological features or symptoms; (3) Results: For the preclinical reports, 45 animals treated with GBE, in six studies, were subjected to cognitive function assessments by the Morris water maze. GBE was shown to reduce the escape latencies in several studies, in both rats and mice (I2 > 70%, p < 0.005). For the clinical trials, eight trials, including 2100 individuals, were conducted. The results show that GBE improved the SKT and ADAS-Cog scores in early-stage AD patients after high doses and long-term administration; (4) Conclusions: GBE displayed generally consistent anti-AD effects in animal experiments, and it might improve AD symptoms in early-stage AD patients after high doses and long-term administration. A lack of sample size calculations and the poor quality of the methods are two obvious limitations of the studies. Nevertheless, the preclinical and clinical data suggest that further large-scale clinical trials may be needed in order to examine the effects of long-term GEB administration on early-stage AD.

Protopine promotes the proteasomal degradation of pathological tau in Alzheimer's disease models via HDAC6 inhibition.

BACKGROUND: Collective evidences have indicated that intracellular accumulation of hyperphosphorylated tau forms neurofibrillary tangles in the brain, which impairs memory, cognition and affects social activities in Alzheimer's disease (AD). PURPOSE: To investigate the tau-reducing, and memory-enhancing properties of protopine (PRO), a natural alkaloid isolated from Chinese herbal medicine Corydalis yanhusuo (Yanhusuo in Chinese). STUDY DESIGN: By using Histone deacetylase 6 (HDAC6) profiling and immunoprecipitation assays, we assessed that PRO mediated the heat shock protein 90 (HSP90) chaperonic activities for the degradation of pathological tau in AD cell culture models. To study the efficacy of PRO in vivo, we employed 3xTg-AD and P301S tau mice models. METHODS: Liquid chromatography/quadrupole time-of-flight mass spectrometry was used to analyze the pharmacokinetic profile of PRO. Seven-month-old 3xTg-AD mice and 1.5-month-old P301S mice were administered PRO (1 and 2.5 mg/kg) orally every day. Morris water maze, contextual fear conditioning and rotarod assays were applied for studying memory functions. Sarkosyl differential centrifugation was used to analyze soluble and insoluble tau. Immunohistochemical analysis were performed to determine tau deposits in AD mice's brain sections. Molecular docking, binding affinity studies and primary cell culture studies were performed to demonstrate the mechanism of action of PRO in silico and in vitro. RESULTS: Our pharmacokinetic profiling demonstrated that PRO significantly entered the brain at a concentration of 289.47 ng/g, and specifically attenuated tau pathology, improved learning and memory functions in both 3xTg-AD and P301S mice. Docking, binding affinity studies, and fluorometric assays demonstrated that PRO directly bound to the catalytic domain 1 (CD1) of HDAC6 and down-regulated its activity. In primary cortical neurons, PRO enhanced acetylation of α-tubulin, indicating HDAC6 inhibition. Meanwhile, PRO promoted the ubiquitination of tau and recruited heat shock protein 70 (HSP70) and heat shock cognate complex 71 (HSC70) for the degradation of pathological tau via the ubiquitin-proteasomal system (UPS). CONCLUSION: We identified PRO as a natural HDAC6 inhibitor that attenuated tau pathology and improved memory dysfunctions in AD mice. The findings from this study provides a strong justification for future clinical development of plant-derived protopine as a novel agent for the treatment of tau-related neurodegenerative diseases.

Active Substances from Callicarpa nudiflora Exert Anti-Cervicitis Effects and Regulate NLRP3-Associated Inflammation.

Luohuazizhu suppository is a Traditional Chinese Medicine used in clinic to treat cervicitis, which is prepared from Callicarpa nudiflora Hook. et Arn (C. nudiflora), an herbal Chinese medicine named Luohuazizhu. This study aimed to figure out the active constituents of C. nudiflora and the potential mechanism for its anti-cervicitis effect. The ethanol extract in C. nudiflora (CNE) and the different fractions of CNE extracted by petroleum ether (CNE-p), dichloromethane (CNE-d), and n-butanol (CNE-b) were tested in vivo for their anti-cervicitis effects. Then the isolated compounds from the CNE-p were tested in vitro for their anti-inflammatory activities. The results displayed that CNE-p, CNE-d, and CNE-b exhibited adequate anti-cervicitis effects, with CNE-p showing the highest efficacy. Further experiment demonstrated that CNE-p could significantly inhibit the expression of NLRP3 in vitro. Six diterpenoids obtained from the CNE-p showed the ability to regulate inflammatory factor levels in vitro. Among these compounds, compounds 1 (callicarpic acid A) and 2 (syn-3,4-seco-12S-hydroxy-15,16-epoxy-4(18),8(17),3(16),14(15)-labdatetraen-3-oic acid) were the most effective agents, and they also inhibited the expression level of NLRP3 in vitro. The results confirmed that C. nudiflora has significant anti-cervicitis effects and the diterpenoids were most likely to be its active components. These data provide scientific support for the clinic usage of Luohuazizhu suppository and the development of new agents in treating cervicitis.

The effect and underlying mechanisms of garlic extract against cognitive impairment and Alzheimer's disease: A systematic review and meta-analysis of experimental animal studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Alzheimer's disease (AD) is the main cause of dementia, and according to traditional Chinese medicine (TCM), it is leaded by the deficiency of essence, qi, and blood. Allii sativi bulbus, acrid and warm, is traditionally used as the important adjuvant and conductant drug to distribute essence-qi throughout the body, fortify the spleen and harmonize the stomach. Garlic (Allium sativum L., Alliaceae) has also been reported to display potential anti-AD effect both in vitro and in vivo studies, while no systematic review of these studies has been conducted. AIM OF THE STUDY: This review aims to provide a comprehensive evaluation of the effect and underlying mechanism of garlic extract against cognitive impairment and AD neuropathology through meta-analysis and sensitivity analysis. MATERIALS AND METHODS: Eligible studies were searched from PubMed, Web of Science and EMBASE from February to March in 2020, and 13 studies describing the effect of garlic extract in AD animal models (551 mice and 88 rats) were identified. RESULTS: Analysis of these studies showed that garlic extract could reduce cerebral Aß levels [Aß40: SMD -8.62(-11.75, -5.49), p < 0.00001 and Aß42: SMD -11.70(-18.01, -5.39), p=0.0003], and increase the number of right crossings in MWM [SMD 2.87(1.48, 4.26), p < 0.0001] in AD animals. However, moderate risk of bias (quality score ranged from 40% to 60%) is revealed by SYRCLE's checklist, mainly because of the lacks of sample size calculation, random allocation and blind assessment. CONCLUSIONS: This review shows that garlic extract may be effective in alleviating cognitive impairment and neuropathology in AD animal models. High quality AD animal studies with enough sample size and more comprehensive evaluation of outcomes are needed to further confirm the results.

Natural Alkaloid Compounds as Inhibitors for Alpha-Synuclein Seeded Fibril Formation and Toxicity.

The accumulation and aggregation of α-synuclein (α-syn) is the main pathologic event in Parkinson's disease (PD), dementia with Lewy bodies, and multiple system atrophy. α-Syn-seeded fibril formation and its induced toxicity occupy a major role in PD pathogenesis. Thus, assessing compounds that inhibit this seeding process is considered a key towards the therapeutics of synucleinopathies. Using biophysical and biochemical techniques and seeding-dependent cell viability assays, we screened a total of nine natural compounds of alkaloid origin extracted from Chinese medicinal herbs. Of these compounds, synephrine, trigonelline, cytisine, harmine, koumine, peimisine, and hupehenine exhibited in vitro inhibition of α-syn-seeded fibril formation. Furthermore, using cell viability assays, six of these compounds inhibited α-syn-seeding-dependent toxicity. These six potent inhibitors of amyloid fibril formation and toxicity caused by the seeding process represent a promising therapeutic strategy for the treatment of PD and other synucleinopathies.

Lycorine, a natural alkaloid, promotes the degradation of alpha-synuclein via PKA-mediated UPS activation in transgenic Parkinson's disease models.

BACKGROUND: Parkinson's disease (PD) is one of the most common neurodegenerative motor disorders, and is characterized by the presence of Lewy bodies containing misfolded α-synuclein (α-syn) and by selective degeneration of midbrain dopamine neurons. Studies have shown that upregulation of ubiquitin-proteasome system (UPS) activity promotes the clearance of aggregation-prone proteins such as α-syn and Tau, so as to alleviate the neuropathology of neurodegenerative diseases. PURPOSE: To identify and investigate lycorine as a UPS enhancer able to decrease α-syn in transgenic PD models. METHODS: Dot blot was used to screen α-syn-lowering compounds in an inducible α-syn overexpression cell model. Inducible wild-type (WT) and mutant α-syn-overexpressing PC12 cells, WT α-syn-overexpressing N2a cells and primary cultured neurons from A53T transgenic mice were used to evaluate the effects of lycorine on α-syn degradation in vitro. Heterozygous A53T transgenic mice were used to evaluate the effects of lycorine on α-syn degradation in vivo. mCherry-GFP-LC3 reporter was used to detect autophagy-dependent degradation. Ub-R-GFP and Ub-G76V-GFP reporters were used to detect UPS-dependent degradation. Proteasome activity was detected by fluorogenic substrate Suc-Leu-Leu-Val-Tyr-AMC (Suc-LLVY-AMC). RESULTS: Lycorine significantly promoted clearance of over-expressed WT and mutant α-syn in neuronal cell lines and primary cultured neurons. More importantly, 15 days' intraperitoneal administration of lycorine effectively promoted the degradation of α-syn in the brains of A53T transgenic mice. Mechanistically, lycorine accelerated α-syn degradation by activating cAMP-dependent protein kinase (PKA) to promote proteasome activity. CONCLUSION: Lycorine is a novel α-syn-lowering compound that works through PKA-mediated UPS activation. This ability to lower α-syn implies that lycorine has the potential to be developed as a pharmaceutical for the treatment of neurodegenerative diseases, such as PD, associated with UPS impairment and protein aggregations.

Corynoxine Protects Dopaminergic Neurons Through Inducing Autophagy and Diminishing Neuroinflammation in Rotenone-Induced Animal Models of Parkinson's Disease.

Recent studies have shown that impairment of autophagy is related to the pathogenesis of Parkinson's disease (PD), and small molecular autophagy enhancers are suggested to be potential drug candidates against PD. Previous studies identified corynoxine (Cory), an oxindole alkaloid isolated from the Chinese herbal medicine Uncaria rhynchophylla (Miq.) Jacks, as a new autophagy enhancer that promoted the degradation of α-synuclein in a PD cell model. In this study, two different rotenone-induced animal models of PD, one involving the systemic administration of rotenone at a low dosage in mice and the other involving the infusion of rotenone stereotaxically into the substantia nigra pars compacta (SNpc) of rats, were employed to evaluate the neuroprotective effects of Cory. Cory was shown to exhibit neuroprotective effects in the two rotenone-induced models of PD by improving motor dysfunction, preventing tyrosine hydroxylase (TH)-positive neuronal loss, decreasing α-synuclein aggregates through the mechanistic target of the rapamycin (mTOR) pathway, and diminishing neuroinflammation. These results provide preclinical experimental evidence supporting the development of Cory into a potential delivery system for the treatment of PD.

Traditional Chinese medicine compounds regulate autophagy for treating neurodegenerative disease: A mechanism review.

Neurodegenerative diseases (NDs) are common chronic diseases related to progressive damage of the nervous system. Globally, the number of people with an ND is dramatically increasing consistent with the fast aging of society and one of the common features of NDs is the abnormal aggregation of diverse proteins. Autophagy is the main process by which misfolded proteins and damaged organelles are removed from cells. It has been found that the impairment of autophagy is associated with many NDs, suggesting that autophagy has a vital role in the neurodegeneration process. Recently, more and more studies have reported that autophagy inducers display a protective role in different ND experimental models, suggesting that enhancement of autophagy could be a potential therapy for NDs. In this review, the evidence for beneficial effects of traditional Chinese medicine (TCM) regulate autophagy in the models of Alzheimer's disease (AD), Parkinson's disease (PD), and other NDs are presented and common autophagy-related mechanisms are identified. The results demonstrate that TCM which regulate autophagy are potential therapeutic candidates for ND treatment.

The pharmacological activity of epigallocatechin-3-gallate (EGCG) on Alzheimer's disease animal model: A systematic review.

BACKGROUND: Alzheimer's disease (AD) is currently incurable and there is an urgent need to develop new AD drugs. Many studies have revealed the potential neuroprotective effect of Epigallocatechin-3-O-gallate (EGCG), the main antioxidant in green tea, on animal models of AD. However, a systematic review of these reports is lacking. PURPOSE: To assess the effectiveness of EGCG for AD treatment using systematic review and meta-analysis of pre-clinical trials. METHODS: We conducted a systematic search of all available randomized controlled trials (RCTs) performed up to November 2019 in the following electronic databases: ScienceDirect, Web of Science, and PubMed. 17 preclinical studies assessing the effect of EGCG on animal AD models have been identified. Meta-analysis and subgroup analysis was performed to evaluate cognition improvement of various types of AD models. The study quality was assessed using the CAMARADES checklist and the criteria of published studies. RESULTS: Our analysis shows that the methodological quality ranges from 3 to 5, with a median score of 4. According to meta-analysis of random-effects method, EGCG showed a positive effect in AD with shorter escape latency (SMD= -9.24, 95%CI= -12.05 to -6.42) and decreased Aß42 level (SD= -25.74,95%CI= -42.36 to -9.11). Regulation of α-, ß-, γ-secretase activity, inhibition of tau phosphorylation, anti-oxidation, anti-inflammation, anti-apoptosis, and inhibition of AchE activity are reported as the main neuroprotective mechanisms. Though more than 100 clinical trials have been registered on the ClinicalTrials.gov, only one clinical trial has been conducted to test the therapeutic effects of EGCG on the AD progression and cognitive performance. CONCLUSION: Here, we conducted this review to systematically describe the therapeutic potential of EGCG in animal models of AD and hope to provide a more comprehensive assessment of the effects in order to design future clinical trials. Besides, the safety, blood-brain barrier (BBB) penetration and bioavailability issues in conducting clinical trials were also discussed.

Inhibition of alpha-synuclein seeded fibril formation and toxicity by herbal medicinal extracts.

BACKGROUND: Recent studies indicated that seeded fibril formation and toxicity of α-synuclein (α-syn) play a main role in the pathogenesis of certain diseases including Parkinson's disease (PD), multiple system atrophy, and dementia with Lewy bodies. Therefore, examination of compounds that abolish the process of seeding is considered a key step towards therapy of several synucleinopathies. METHODS: Using biophysical, biochemical and cell-culture-based assays, assessment of eleven compounds, extracted from Chinese medicinal herbs, was performed in this study for their effect on α-syn fibril formation and toxicity caused by the seeding process. RESULTS: Salvianolic acid B and dihydromyricetin were the two compounds that strongly inhibited the fibril growth and neurotoxicity of α-syn. In an in-vitro cell model, these compounds decreased the insoluble phosphorylated α-syn and aggregation. Also, in primary neuronal cells, these compounds showed a reduction in α-syn aggregates. Both compounds inhibited the seeded fibril growth with dihydromyricetin having the ability to disaggregate preformed α-syn fibrils. In order to investigate the inhibitory mechanisms of these two compounds towards fibril formation, we demonstrated that salvianolic acid B binds predominantly to monomers, while dihydromyricetin binds to oligomeric species and to a lower extent to monomers. Remarkably, these two compounds stabilized the soluble non-toxic oligomers lacking ß-sheet content after subjecting them to proteinase K digestion. CONCLUSIONS: Eleven compounds were tested but only two showed inhibition of α-syn aggregation, seeded fibril formation and toxicity in vitro. These findings highlight an essential beginning for development of new molecules in the field of synucleinopathies treatment.

A small molecule transcription factor EB activator ameliorates beta-amyloid precursor protein and Tau pathology in Alzheimer's disease models.

Accumulating studies have suggested that targeting transcription factor EB (TFEB), an essential regulator of autophagy-lysosomal pathway (ALP), is promising for the treatment of neurodegenerative disorders, including Alzheimer's disease (AD). However, potent and specific small molecule TFEB activators are not available at present. Previously, we identified a novel TFEB activator named curcumin analog C1 which directly binds to and activates TFEB. In this study, we systematically investigated the efficacy of curcumin analog C1 in three AD animal models that represent beta-amyloid precursor protein (APP) pathology (5xFAD mice), tauopathy (P301S mice) and the APP/Tau combined pathology (3xTg-AD mice). We found that C1 efficiently activated TFEB, enhanced autophagy and lysosomal activity, and reduced APP, APP C-terminal fragments (CTF-ß/α), ß-amyloid peptides and Tau aggregates in these models accompanied by improved synaptic and cognitive function. Knockdown of TFEB and inhibition of lysosomal activity significantly inhibited the effects of C1 on APP and Tau degradation in vitro. In summary, curcumin analog C1 is a potent TFEB activator with promise for the prevention or treatment of AD.

NeuroDefend, a novel Chinese medicine, attenuates amyloid-ß and tau pathology in experimental Alzheimer's disease models.

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder. Amyloid-ß (Aß) and hyper-phosphorylated tau accumulation are accountable for the progressive neuronal loss and cognitive impairments usually observed in AD. Currently, medications for AD offer moderate symptomatic relief but fail to cure the disease; hence development of effective and safe drugs is urgently needed for AD treatment. In this study, we investigated a Chinese medicine (CM) formulation named NeuroDefend (ND), for reducing amyloid ß (Aß) and tau pathology in transgenic AD mice models. Regular oral administration of ND improved cognitive function and memory in 3XTg-AD and 5XFAD mice. In addition, ND reduced beta-amyloid precursor protein (APP), APP C-terminal fragments (CTF-ß/α), Aß and 4G8 positive Aß burden in 3XTg-AD and 5XFAD mice. Furthermore, ND efficiently reduced the levels of insoluble phospho-tau protein aggregates and AT8 positive phospho tau neuron load in 3XTg-AD mice. Hence, ND could be a promising candidate for the treatment of AD in humans.

XIAOPI formula promotes breast cancer chemosensitivity via inhibiting CXCL1/HMGB1-mediated autophagy.

XIAOPI formula is a national approved drug prescribed to patients with high breast cancer risk. Previously we demonstrated that XIAOPI formula could inhibit breast cancer metastasis via suppressing CXCL1 expression, and postulated that "autophagy in cancer" might be one of its most core anti-cancer mechanisms. However, whether XIAOPI formula could be simultaneously applied with chemodrugs and their synergistic mechanisms are still remained unknown. In the present study, XIAOPI formula at non-cytotoxic doses could synergistically enhance the chemosensitivity of breast cancer cells MDA-MB-231 and MCF-7. We found that rapamycin-induced autophagy could reduce the chemosensitivity of breast cancer cells to XIAOPI formula, and the autophagy suppression and chemosensitizing activity of this formula was CXCL1-dependent. The evidence came from that XIAOPI formula was associated with a lower expression of CXCL1 combined with either rapamycin or taxol alone. Besides, the inhibitory effect of XIAOPI formula on the LC3-II and ABCG2 signals was weakened following CXCL1 over-expression, whereas P62 upregulation induced by XIAOPI formula was re-declined. A high throughput - qPCR (HT-qPCR) assay identified HMGB1 as the main autophagic target of XIAOPI formula in chemosensitizing breast cancer. and furhter validation suggested XIAOPI formula exerted chemosensitivity mainly via CXCL1/HMGB1 autophagic axis. Finally, we generated both mice and zebrafish xenotransplantation models bearing MDA-MB-231 breast cancer cells, and found that XIAOPI formula safely enhanced in vivo taxol chemosensitivity on breast cancer. Taken together, XIAOPI formula is a potential adjuvant drug via inhibiting CXCL1/HMGB1-mediated autophagy for breast cancer treatment with good safety.

Neuroprotective effects of berberine in animal models of Alzheimer's disease: a systematic review of pre-clinical studies.

BACKGROUND: Berberine is an isoquinoline alkaloid extracted from various Berberis species which is widely used in East Asia for a wide range of symptoms. Recently, neuroprotective effects of berberine in Alzheimer's disease (AD) animal models are being extensively reported. So far, no clinical trial has been carried out on the neuroprotective effects of berberine. However, a review of the experimental data is needed before choosing berberine as a candidate drug for clinical experiments. We conducted a systematic review on AD rodent models to analyze the drug effects with minimal selection bias. METHODS: Five online literature databases were searched to find publications reporting studies of the effect of berberine treatment on animal models of AD. Up to March 2018, 15 papers were identified to describe the efficacy of berberine. RESULTS: The included 15 articles met our inclusion criteria with different quality ranging from 3 to 5. We analyzed data extracted from full texts with regard to pharmacological effects and potential anti-Alzheimer's properties. Our analysis revealed that in multiple memory defects animal models, berberine showed significant memory-improving activities with multiple mechanisms, such as anti-inflammation, anti-oxidative stress, cholinesterase (ChE) inhibition and anti-amyloid effects. CONCLUSION: AD is likely to be a complex disease driven by multiple factors. Yet, many therapeutic strategies based on lowering ß-amyloid have failed in clinical trials. This suggest that the threapy should not base on a single cause of Alzheimer's disease but rather a number of different pathways that lead to the disease. Overall we think that berberine can be a promising multipotent agent to combat Alzheimer's disease.

Natural alkaloid harmine promotes degradation of alpha-synuclein via PKA-mediated ubiquitin-proteasome system activation.

BACKGROUND: Parkinson's disease (PD) is an age-dependent progressive movement disorder characterized by a profound and selective loss of nigrostriatal dopaminergic neurons. Accumulation of -synuclein (-syn) positive protein aggregates in the substantia nigra is a pathological hallmark of PD, indicating that protein turnover defect is implicated in PD pathogenesis. PURPOSE: This study aims to identify neuroprotective compounds which can alleviate the accumulation of -syn in neuronal cells and dissect the underlying mechanisms. METHODS: High throughput screening was performed by dot blot assay. The degradation of different forms of -syn by candidate compounds were assessed by western blot. The autophagy lysosome pathway and ubiquitin-proteasome system were examined to dissect the degradation pathway. The UPS activity was assessed by cellular UPS substrates degradation assay and biochemical proteasome activity assay. Q-PCR was performed to test the mRNA level of different proteasome subunits. Furthermore, Neuroprotective effect of candidate compound was tested by LDH assay and PI staining. RESULTS: Through the high throughput screening, harmine was identified as a potent -syn lowering compound. The time-dependent and dose-dependent effects of harmine on the degradation of different forms of -syn were further confirmed. Harmine could dramatically promote the degradation of UPS substrates GFP-CL1, Ub-R-GFP and Ub-G76V-GFP, and activate cellular proteasome activity. Mechanistically, harmine dramatically enhanced PKA phosphorylation to enhance proteasome subunit PSMD1 expression. PKA inhibitor blocked the effects of harmine in activating UPS, up regulating PSMD1 and promoting -syn degradation, indicating that harmine enhances UPS function via PKA activation. Moreover, harmine efficiently rescued cell death induced by over-expression of -syn, via UPS-dependent manner. CONCLUSION: Harmine, as a new proteasome enhancer, may have potential to be developed into therapeutic agent against neurodegenerative diseases associated with UPS dysfunction and aberrant proteins accumulation.