Kai-Xin-San Inhibits Tau Pathology and Neuronal Apoptosis in Aged SAMP8 Mice

Kai-Xin-San ameliorates mild cognitive impairment in SAMP8 mice by inhibiting neuroinflammation and pyroptosis via NLRP3/Caspase-1 pathway modulation

Mild Cognitive Impairment (MCI) represents a critical stage between normal aging and dementia, with limited effective interventions currently available. This study investigated the effects of Kai-Xin-San (KXS), a traditional Chinese herbal formula, on cognitive function, neuroinflammation, and pyroptosis in a senescence-accelerated prone 8 (SAMP8) mouse model of MCI. SAMP8 mice were treated with KXS for 8 weeks, followed by behavioral tests, biochemical analyses, and histological examinations. KXS significantly improved spatial memory, working memory, and executive function in SAMP8 mice. Furthermore, KXS treatment reduced β-amyloid (Aβ) deposition, attenuated neuroinflammation by decreasing pro-inflammatory cytokine levels (IL-1β, IL-18, IL-6, TNF-α), and inhibited microglia activation in the hippocampus. Notably, KXS suppressed pyroptosis by modulating the NLRP3/Caspase-1 signaling pathway, as evidenced by reduced expression of NLRP3, ASC, Caspase-1, and GSDMD. These effects were abolished by treatment with the NLRP3 inflammasome agonist Nigericin, suggesting that NLRP3 inhibition is a key mechanism of KXS action. Our findings reveal a novel mechanism by which KXS exerts neuroprotective effects in MCI, simultaneously targeting Aβ accumulation, neuroinflammation, and pyroptosis. This multi-target approach of KXS highlights its potential as a therapeutic strategy for MCI and warrants further investigation in clinical settings.

Senescence accelerated mouse-prone 8: a model of neuroinflammation and aging with features of sporadic Alzheimer's disease

The large majority of Alzheimer's disease (AD) cases are sporadic with unknown genetic causes. In contrast, only a small percentage of AD cases are familial, with known genetic causes. Paradoxically, there are only few validated mouse models of sporadic AD but many of familial AD. Senescence accelerated mouse-prone 8 (SAMP8) mice are a model of accelerated aging with features of sporadic AD. They exhibit a more complete suite of human AD-relevant pathologies than most familial models. SAMP8 brains are characterized by inflammation, glial activation, b-amyloid deposits, and hyperphosphorylated Tau. The excess amyloid deposits congregate around blood vessels leading to vascular impairment and leaky BBBs in these mice. SAMP8 mice also exhibit neuronal cell death, a feature not typically seen in models of familial AD. Additionally, adult hippocampal neurogenesis is decreased in SAMP8 mice and correspondingly, they have reduced cognitive ability. In line with this, hippocampal LTP is significantly compromised in SAMP8 mice. No model is perfect and SAMP8 mice are limited by the lack of clarity about their genomic differences from control Senescence Accelerated Mouse-Resistant 1 (SAMR1) mice although their transcriptomics changes are being revealed. To further complicate matters, multiple substrains of SAMP8 mice have emerged over the years, sometimes making comparisons of studies difficult. Despite these challenges, we argue that SAMP8 mice can be useful for studying AD-relevant symptoms and propose important experiments to strengthen this already useful model.

Evaluation of the chronic oral toxicity of the classical ancient prescription Kai-Xin-San

ETHNOPHARMACOLOGICAL RELEVANCE

The Kai-Xin-San (KXS), as an ancient classic prescription, has been used for the treatment of amnesia for thousands of years. Modern clinical and non-clinical pharmacological studies have found that it has significant therapeutic effects on dementia and depression, but there are relatively few studies on its safety.

AIM OF THE STUDY

Subacute and chronic toxicity studies were conducted to investigate the symptoms, severity, target organs, development and recovery of toxic reactions, as well as the toxic dose. These studies provide technical data for ensuring the safety of KXS.

MATERIALS AND METHODS

In the sub-acute toxicity study, rats were orally administered KXS at doses of 0.80, 1.61, 3.22, and 6.43 g/kg body weight for a duration of 4 weeks. In the chronic toxicity study, rats were orally administered KXS at doses of 0.27, 0.81, and 2.43 g/kg body weight for a duration of 26 weeks, and a withdrawal study was conducted for a period of 4 weeks after the treatment.The rats were observed daily for clinical signs and mortality. Changes in body weight, food consumption, and water consumption were periodically monitored. Additionally, urinalysis results, hematological and biochemical parameters, relative organ weights, and pathology were monitored at specific observation time points.

RESULTS

In the sub-acute toxicity study, necropsy of dead and moribund rats revealed evident distension and swelling of the gastrointestinal tract, as well as thinning of the intestinal wall. The main adverse reactions observed included flatulence, piloerection, abnormal breathing sounds, and emaciation. Doses of 1.61 g/kg and below did not cause animal death. The gastrointestinal system is the main target organ of toxicity. In the chronic toxicity study, the no-observed-adverse-effect-level (NOAEL) of KXS was 0.27 g/kg, and its toxic effects were primarily concentrated in the gastrointestinal system. This led to secondary pathological changes in the immune system, hematopoietic system, and heart, suggesting that relevant indicators should be monitored when large doses are used clinically for an extended period of time.

CONCLUSIONS

During the rodent toxicity evaluation, severe gastrointestinal damage was observed when KXS, powdered with crude drugs, was administered. The NOAEL for rats was found to be 0.27 g/kg/day.

The spectrum-efficacy correlation of Kai-Xin-San for cognition of Aβ42 transgenic Drosophila and verification of its active ingredients

Introduction

This study aims to establish the fingerprint spectra of Kai-Xin-San (KXS) and investigate its spectrum-effect relationship in treating Alzheimer's disease (AD).

Methods

Initially, the fingerprints of 15 batches of KXS were established and analyzed using HPLC, with the method's precision, stability, and repeatability thoroughly evaluated. Subsequently, the effects of the 15 batches of KXS were assessed in an olfactory escape memory experiment, utilizing Aβ42 transgenic drosophila as a model. Finally, the spectrum-effect relationship between the KXS fingerprint and memory improvement was analyzed, with the active ingredients subjected to validation testing.

Results

The results identified seventeen common peaks in the fingerprint, and eight active components were determined: polygalaxanthone III, 3-6-disinapoylsucrose, ginsenoside Rg1, ginsenoside Rb1, β-asarone, α-asarone, dehydrotumulosic acid, and dehydropachymic acid. Treatment with KXS (1%, for 4 days) significantly enhanced the performance index of Aβ42 flies in the olfactory experiment. Both spectrum-effect analysis and validation tests indicated that polygalaxanthone III, ginsenoside Rg1, ginsenoside Rb1, β-asarone, and α-asarone were positively correlated with the performance index and improved the performance index in the olfactory experiment. The HPLC fingerprint method for KXS demonstrated excellent precision, accuracy, and reproducibility, making it suitable for quality evaluation and control of KXS. Polygalaxanthone III, ginsenoside Rg1, ginsenoside Rb1, β-asarone, and α-asarone are identified as potential active ingredients of KXS for anti-AD effects.

Discussion

These findings provide an experimental basis for developing new drugs based on KXS and its active ingredient combinations.

KaiXinSan improves learning and memory impairment by regulating cholesterol homeostasis in mice overloaded with 27-OHC

Cholesterol and its oxidative products-oxysterols homeostasis- play a crucial role in maintaining cognitive function. Chinese medicine KaiXinSan (KXS) has demonstrated effectiveness in treating mental illness and regulating cognitive dysfunction of Alzheimer's disease (AD). The purpose of this article is to explore whether the KXS can enhance cognitive function by regulating cholesterol homeostasis. Employing the 27-hydroxy cholesterol (27-OHC) induced mice model of cognitive dysfunction and coculture model of assessment neurocyte damage, we investigated learning and memory abilities while concurrently addressing the reduction of neuronal cell damage through the regulation of cholesterol metabolism. 21 days of KXS treatment improved the learning and memory ability in mice 27-OHC-overloading by alleviating the exacerbated deposition of amyloid-β (Aβ), reducing inflammatory reactions, and mitigating synaptic plasticity damage. Additionally, it repaired myelin sheath function. More importantly, KXS significantly affects the metabolism of central cholesterol by substantially inhibiting the expression of liver X receptor (LXR), ATP-binding cassette transporter (ABCA1, ABCG1), apolipoprotein E (ApoE) and upregulated cytochrome P450 46A1(CYP46A1). Furthermore, KXS may alleviate 27-OHC-induced neuronal inflammation and apoptosis by promoting the conversion of cholesterol to 24-hydroxycholesterol (24-OHC) via CYP46A1 and suppressing cholesterol release from astrocyte cells. Altogether, our results demonstrate that KXS can prevent learning and memory impairments induced by 27-OHC loading. This effect may be related to its multitarget capability in promoting the conversion of excessive cholesterol to 24-OHC and maintaining a balance in cholesterol homeostasis and metabolism between neurons and astrocyte cells.

Oral Chinese herbal medicine combined with donepezil for mild cognitive impairment: A systematic review and meta-analysis

BACKGROUND

This study aims to evaluate the add-on effects of oral Chinese herbal medicine (CHM) for mild cognitive impairment (MCI), when used in addition to donepezil compared to donepezil alone.

METHODS

Randomized controlled trials comparing these treatments across all types of MCI were identified from nine databases and three registers until August 2023. Outcome measures were Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and adverse events (AEs). Methodological quality was assessed using Cochrane risk-of-bias tool, and evidence certainty was evaluated using the GRADE method.

RESULTS

Involving 1611 participants across 20 studies, meta-analysis results indicate that oral CHM combined with donepezil significantly improved cognitive function in MCI patients compared to donepezil alone, as evidenced by MMSE (1.88 [1.52, 2.24], I2 = 41%, 12 studies, 993 participants) and MoCA (MD: 2.01 [1.57, 2.44], I2 = 52%, 11 studies, 854 participants). Eleven studies reported details of AEs, identifying gastrointestinal symptoms and insomnia as the most common symptoms. No significant difference in AEs frequency was found between the groups (RR: 0.91 [0.59, 1.39], I2 = 4%, 11 studies, 808 participants). All 20 studies were evaluated as having "some concerns" regarding the overall risk of bias. The certainty of evidence for MMSE was "moderate" and "low" for MoCA. From frequently utilized herbs, two classical CHM formulae were identified: Kai xin san and Si wu decoction. The observed treatment effects of commonly used herbs may be exerted through multiple pharmacological mechanisms, including anti-inflammatory, anti-oxidative stress, anti-apoptotic actions, promotion of neuronal survival and modulation of the cholinergic system.

CONCLUSIONS

The concurrent use of oral CHM and donepezil appears to be more effective than donepezil alone in improving the cognitive function of MCI, without leading to an increase in AEs. While recognizing concerns of overall methodological quality, this combined therapy should be considered as an alternative option for clinical practice.

Herbal medicines in Alzheimer's disease and the involvement of gut microbiota

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory loss and cognitive impairment. It severely affects the quality of life of victims. The prevalence of AD has been increasing in recent years. Therefore, it is of great importance to elucidate the pathogenic mechanism of AD and search for effective therapeutic approaches. Gut microbiota dysbiosis, an altered state of gut microbiota, has been well known for its involvement in the pathogenesis of AD. Much effort has been made in searching for approaches capable of modulating the composition of gut microbiota in recent years. Herbal medicines have attracted extensive attention in recent decades for the prevention and treatment of AD. Here, we gave an overview of the recent research progress on the modulatory effects of herbal medicines and herbal formulae on gut microbiota as well as the possible beneficial effects on AD, which may provide new insights into the discovery of anti-AD agents and their therapeutic potential for AD through modulating the composition of gut microbiota.

Classic Famous Prescription Kai-Xin-San Ameliorates Alzheimer's Disease via the Wnt/β-Catenin Signaling Pathway

Kai-Xin-San (KXS) is a classic famous prescription composed of Polygalae Radix, Ginseng Radix et Rhizoma, Acori Tatarinowii Rhizoma, and Poria. Clinically, KXS is effective in treating amnesia and regulating cognitive dysfunction of Alzheimer's disease (AD), whereas its mechanism of action is still unclear. In this study, the AD model rats were established by combining intraperitoneal injection of D-galactose (150 mg/kg/day) and intracerebral injection of Aβ25-35 (10 μL) to investigate the meliorative effect of KXS on AD and explore its mechanism. After 1-month KXS treatment, Morris water maze test showed that different doses of KXS all improved the cognitive impairment of AD rats. The results of hematoxylin and eosin staining, Nissl staining, and Tunnel staining showed that the neuron injury in the hippocampal CA1 region of the AD rats was markedly improved after KXS treatment. Concurrently, KXS reversed the levels of biochemical indexes of AD rats. Furthermore, the protein expressions of Wnt1 and β-catenin in KXS groups were remarkably increased, while the expressions of Bax and caspase-3 were significantly decreased. Besides, KXS-medicated serum reduced the levels of tumor necrosis factor-α, interleukin-1β, and reactive oxygen species and regulated the protein expressions of β-catenin, glycogen synthase kinase-3β (GSK-3β), p-GSK-3β, Bax, and caspase-3 in Aβ25-35-induced pheochromocytoma cells. Most importantly, this effect was attenuated by the Wnt inhibitor IWR-1. Our results suggest that KXS improves cognitive and memory function of AD rats, and its neuroprotective mechanism may be mediated through the Wnt/β-catenin signaling pathway.

Constituents, pharmacological activities, pharmacokinetic studies, clinical applications, and safety profile on the classical prescription Kaixinsan

Kaixinsan (KXS) is a noteworthy classical prescription, which consists of four Chinese medicinal herbs, namely Polygalae Radix, Ginseng Radix et Rhizoma, Poria, and Acori Tatarinowii Rhizoma. KXS was initially documented in the Chinese ancient book Beiji Qianjin Yaofang written by Sun Simiao of the Tang Dynasty in 652 A.D. As a traditional Chinese medicine (TCM) prescription, it functions to nourish the heart and replenish Qi, calm the heart tranquilize the mind, and excrete dampness. Originally used to treat amnesia, it is now also effective in memory decline and applied to depression. Although there remains an abundance of literature investigating KXS from multiple aspects, few reviews summarize the features and research, which impedes better exploration and exploitation of KXS. This article intends to comprehensively analyze and summarize up-to-date information concerning the chemical constituents, pharmacology, pharmacokinetics, clinical applications, and safety of KXS based on the scientific literature, as well as to examine possible scientific gaps in current research and tackle issues in the next step. The chemical constituents of KXS primarily consist of saponins, xanthones, oligosaccharide esters, triterpenoids, volatile oils, and flavonoids. Of these, saponins are the predominant active ingredients, and increasing evidence has indicated that they exert therapeutic properties against mental disease. Pharmacokinetic research has illustrated that the crucial exposed substances in rat plasma after KXS administration are ginsenoside Re (GRe), ginsenoside Rb1 (GRb1), and polygalaxanthone III (POL). This article provides additional descriptions of the safety. In this review, current issues are highlighted to guide further comprehensive research of KXS and other classical prescriptions.

Polygala tenuifolia and Acorus tatarinowii in the treatment of Alzheimer's disease: a systematic review and meta-analysis

Background: The complexity of Chinese medicine treatment for Alzheimer's disease (AD) utilizing a multi-herb therapy makes the evidence in current studies insufficient. Herb pairs are the most fundamental form of multi-herb formulae. Among the Chinese herbal formulas for AD treatment, Polygala tenuifolia (PT) and Acorus tatarinowii (AT) appeared as the most commonly used herbal pairs in combination. Objective: The aim of this study is to evaluate the clinical efficacy and safety of the combination of PT and AT in the treatment of AD. Methods: We systematically searched and screened randomized controlled trials of pairing PT and AT for the treatment of AD patients in eight databases with a search deadline of June 26, 2023. Authors, year of publication, title, and basic information such as subject characteristics (age, sex, and race), course of disease, control interventions, dose, and treatment duration were extracted from the screened studies. Primary outcomes assessed included mini-mental state examination (MMSE), activities of daily living (ADL), and AD assessment scale-cognitive subscale (ADAS-cog), while secondary outcomes included efficiency and adverse events. The quality of the included studies was assessed using the Cochrane risk of bias tool. The mean difference with 95% confidence intervals (MD [95% CI]) and risk ratio (RR) was selected as the effect size, and the data were analyzed and evaluated using RevMan 5.4 and Stata 16. Results: A total of sixteen eligible and relevant studies involving 1103 AD participants were included. The combination of PT and AT plus conventional drugs was superior to single conventional drugs in MMSE [MD = 2.57, 95%CI: (1.44, 3.69); p < 0.00001; I 2 = 86%], ADL [MD = -3.19, 95%CI: (-4.29, -2.09); p < 0.00001; I 2 = 0%], and ADAS-cog scores [MD = -2.09, 95%CI: (-3.07, -1.10); p < 0.0001; I 2 = 0%]. The combination of PT and AT plus conventional drugs had a significantly more favorable benefit in clinical effectiveness [RR = 1.27, 95%CI: (1.12, 1.44); p = 0.0002; I 2 = 0%]. Adverse events were not increased with the combination of PT and AT plus conventional drugs compared to conventional drugs [RR = 0.65, 95%CI: (0.35, 1.19); p = 0.16; I 2 = 0%]. The experimental group treated with the combination of PT and AT alone for AD was comparable in MMSE, ADL, and ADAS-cog scores compared with the control group treated with single conventional drugs. Conclusion: Compared to single conventional drugs, the combination of PT and AT may be used as an alternative therapy to improve global cognition and functioning in AD, and the combination of PT and AT as adjunctive therapy appears to produce a better therapeutic response to AD in terms of efficacy without increasing the risk of adverse events. However, the very low to low quality of available evidence limits confidence in the findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023444156.

Research on the quality markers of antioxidant activity of Kai-Xin-San based on the spectrum-effect relationship

Background: Kai-Xin-San (KXS) is one of the classic famous traditional Chinese medicine prescriptions for amnesia, which has been applied for thousands of years. Modern pharmacological research has found that KXS has significant therapeutic efficacy on nervous system diseases, which is related to its antioxidant activity. However, the antioxidant material basis and quality markers (Q-makers) of KXS have not been studied. Objective: The objective of this study is to explore the Q-makers of antioxidant activity of KXS based on spectrum-effect relationship. Methods: Specifically, the metabolites in KXS extracts were identified by UPLC-Q-Exactive Orbitrap MS/MS. The fingerprint profile of KXS extracts were established by high-performance liquid chromatography (HPLC) and seven common peaks were identified. Meanwhile, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) test was used to evaluate the free radical scavenging ability of KXS. The spectrum-effect relationship between its HPLC fingerprint and DPPH free radical scavenging activity was preliminarily examined by the Pearson correlation analysis, grey relation analysis (GRA), and orthogonal partial least squares discrimination analysis (OPLS-DA). Further, the antioxidant effect of KXS and its Q-makers were validated through human neuroblastoma (SH-SY5Y) cells experiment. Results: The results showed that 103 metabolites were identified from KXS, and the similarity values between HPLC fingerprint of twelve batches of KXS were greater than 0.900. At the same time, the results of Pearson correlation analysis showed that the peaks 8, 1, 14, 17, 18, 24, 16, 21, 15, 13, 6, 5, and 3 from KXS were positively correlated with the scavenging activity values of DPPH. Combined with the results of GRA and OPLS-DA, peaks 1, 3, 5 (Sibiricose A6), 6, 13 (Ginsenoside Rg1), 15, and 24 in the fingerprints were screen out as the potential Q-makers of KXS for antioxidant effect. Besides, the results of CCK-8 assay showed that KXS and its Q-makers remarkably reduced the oxidative damage of SH-SY5Y cells caused by H2O2. However, the antioxidant activity of KXS was decreased significantly after Q-makers were knocked out. Conclusion: In conclusion, the metabolites in KXS were successfully identified by UPLC-Q-Exactive Orbitrap MS/MS, and the Q-makers of KXS for antioxidant effect was analyzed based on the spectrum-effect relationship. These results are beneficial to clarify the antioxidant material basis of KXS and provide the quality control standards for new KXS products development.

Antidepressant pharmacological mechanisms: focusing on the regulation of autophagy

The core symptoms of depression are anhedonia and persistent hopelessness. Selective serotonin reuptake inhibitors (SSRIs) and their related medications are commonly used for clinical treatment, despite their significant adverse effects. Traditional Chinese medicine with its multiple targets, channels, and compounds, exhibit immense potential in treating depression. Autophagy, a vital process in depression pathology, has emerged as a promising target for intervention. This review summarized the pharmacological mechanisms of antidepressants by regulating autophagy. We presented insights from recent studies, discussed current research limitations, and proposed new strategies for basic research and their clinical application in depression.

Identification of Uncaria rhynchophylla in the Potential Treatment of Alzheimer's Disease by Integrating Virtual Screening and In Vitro Validation

Uncaria rhynchophylla (Gouteng in Chinese, GT) is the main medicine in many traditional recipes in China. It is commonly used to alleviate central nervous system (CNS) disorders, although its mechanism in Alzheimer's disease is still unknown. This study was designed to predict and validate the underlying mechanism in AD treatment, thus illustrating the biological mechanisms of GT in treating AD. In this study, a PPI network was constructed, KEGG analysis and GO analysis were performed, and an "active ingredient-target-pathway" network for the treatment of Alzheimer's disease was constructed. The active ingredients of GT were screened out, and the key targets were performed by molecular docking. UHPLC-Q-Exactive Orbitrap MS was used to screen the main active ingredients and was compared with the network pharmacology results, which verified that GT did contain the above ingredients. A total of targets were found to be significantly bound up with tau, Aβ, or Aβ and tau through the network pharmacology study. Three SH-SY5Y cell models induced by okadaic acid (OA), Na2S2O4, and H2O2 were established for in vitro validation. We first found that GT can reverse the increase in the hyperphosphorylation of tau induced by OA to some extent, protecting against ROS damage. Moreover, the results also indicated that GT has significant neuroprotective effects. This study provides a basis for studying the potential mechanisms of GT in the treatment of AD.

Osthole/borneol thermosensitive gel via intranasal administration enhances intracerebral bioavailability to improve cognitive impairment in APP/PS1 transgenic mice

Alzheimer's disease (AD) poses a significant threat to the global elderly population. Traditional Chinese medicine (TCM) has been widely utilized in the treatment of AD. Osthole, a bioactive ingredient classified as an "emperor" in many TCM formulas, has been demonstrated to effectively alleviate AD symptoms. However, its low bioavailability in the brain has limited its clinical application. This study aimed to increase the intracerebral bioavailability of osthole by using borneol as a "courier," based on the classical "Emperor-Minister-Assistant-Courier" model, and to investigate the enhanced pharmacological performance of osthole on AD. Results indicated that a suitable in situ thermosensitive gel matrix for intranasal administration mixed with osthole and borneol consists of P407 at 20%, P188 at 7%, and PEG300 at 6%. The concentration of osthole in the cerebrospinal fluid increased almost tenfold after intranasal administration of osthole/borneol compared to oral administration. Mechanisms showed that borneol as a "courier" opened up intercellular space and loosened the tight junctions of the nasal mucosa by suppressing ZO-1 and occludin expression, thereby expediting the nose-to-brain route and guiding osthole as "emperor" to its target in the brain. Osthole assisted by borneol demonstrated significantly improved efficiency in suppressing cleaved caspase-3 expression, increasing the Bcl-2/Bax ratio, improving T-SOD and catalase expression, reducing malondialdehyde levels, inhibiting neuron apoptosis, and decreasing Aβ levels by inhibiting BACE1 expression to alleviate cognitive impairment in APP/PS1 mice compared to osthole alone. Overall, our study demonstrated that the intracerebral bioavailability of osthole profoundly improved with intranasal administration of osthole/borneol and provided a wider application of TCM for AD treatment with higher intracerebral bioavailability.

Kai-Xin-San protects against mitochondrial dysfunction in Alzheimer's disease through SIRT3/NLRP3 pathway

BACKGROUND

Kai-Xin-San (KXS) has been reported to have a good curative impact on dementia. The purpose of the study was to determine whether KXS might ameliorate cognitive deficits in APP/PS1 mice and to evaluate its neuroprotective mechanism.

METHODS

APP/PS1 mice were employed as an AD animal model; Aβ_1-42 and KXS-containing serum were used in HT22 cells. Four different behavioral tests were used to determine the cognitive ability of mice. Nissl staining was utilized to detect hippocampal neuron changes. ROS, SOD, and MDA were used to detect oxidative stress levels. Transmission electron microscopy and Western blot were used to evaluate mitochondrial morphology, mitochondrial division, and fusion state. Western blotting and immunofluorescence identified PSD95, BDNF, NGF, SYN, SIRT3, and NLRP3 inflammasome levels.

RESULTS

The results indicated that KXS protected APP/PS1 mice against cognitive impairments. KXS suppressed neuronal apoptosis and oxidative stress among APP/PS1 mice. KXS and KXS-containing serum improved mitochondrial dysfunction and synaptic and neurotrophic factors regarding APP/PS1 mice. In addition, KXS and KXS-containing serum enhanced mitochondrial SIRT3 expression and reduced NLRP3 inflammasome expression in APP/PS1 mice.

CONCLUSION

KXS improves cognitive dysfunction among APP/PS1 mice via regulating SIRT3-mediated neuronal cell apoptosis. These results suggested that KXS was proposed as a neuroprotective agent for AD progression.

Neuroprotective Effects of a Multi-Herbal Extract on Axonal and Synaptic Disruption in Vitro and Cognitive Impairment in Vivo

Background

Alzheimer's disease (AD) is a multifactorial disorder characterized by cognitive decline. Current available therapeutics for AD have limited clinical benefit. Therefore, preventive therapies for interrupting the development of AD are critically needed. Molecules targeting multifunction to interact with various pathlogical components have been considered to improve the therapeutic efficiency of AD. In particular, herbal medicines with multiplicity of actions produce cognitive benefits on AD. Bugu-M is a multi-herbal extract composed of Ganoderma lucidum (Antler form), Nelumbo nucifera Gaertn., Ziziphus jujuba Mill., and Dimocarpus longan, with the ability of its various components to confer resilience to cognitive deficits.

Objective

To evaluate the potential of Bugu-M on amyloid-β (Aβ) toxicity and its in vitro mechanisms and on in vivo cognitive function.

Methods

We illustrated the effect of Bugu-M on Aβ_25-35-evoked toxicity as well as its possible mechanisms to diminish the pathogenesis of AD in rat cortical neurons. For cognitive function studies, 2-month-old female 3×Tg-AD mice were administered 400 mg/kg Bugu-M for 30 days. Behavioral tests were performed to assess the efficacy of Bugu-M on cognitive impairment.

Results

In primary cortical neuronal cultures, Bugu-M mitigated Aβ-evoked toxicity by reducing cytoskeletal aberrations and axonal disruption, restoring presynaptic and postsynaptic protein expression, suppressing mitochondrial damage and apoptotic signaling, and reserving neurogenic and neurotrophic factors. Importantly, 30-day administration of Bugu-M effectively prevented development of cognitive impairment in 3-month-old female 3×Tg-AD mice.

Conclusion

Bugu-M might be beneficial in delaying the progression of AD, and thus warrants consideration for its preventive potential for AD.

Therapeutic potential of Polygala saponins in neurological diseases

BACKGROUND

There are many types of neurological diseases with complex etiologies. At present, most clinical drugs can only relieve symptoms but cannot cure these diseases. Radix Polygalae, a famous traditional Chinese medicine from the root of plants of the genus Polygala, has the traditional effect of treating insomnia, forgetfulness, and palpitation and improving intelligence and other symptoms of neurological diseases. Saponins are important bioactive components of plants of the genus Polygala and exhibit neuroprotective effects.

PURPOSE

This review aimed to summarize the traditional use of Polygala species and discuss the latest phytochemical, pharmacological, and toxicological findings, mainly with regard to Polygala saponins in the treatment of neurological disorders.

METHODS

Literature was searched and collected using databases, including PubMed, Science Direct, CNKI, and Google Scholar. The search terms used included "Polygala", "saponins", "neurological diseases", "Alzheimer's disease", "toxicity", etc., and combinations of these keywords. A total of 1202 papers were retrieved until August 2022, and we included 135 of these papers on traditional uses, phytochemistry, pharmacology, toxicology and other fields.

RESULTS

This literature review mainly reports on the traditional use of the Polygala genus and prescriptions containing Radix Polygalae in neurological diseases. Phytochemical studies have shown that plants of the genus Polygala mainly include saponins, flavonoids, oligosaccharide esters, alkaloids, coumarins, lignans, flavonoids, etc. Among them, saponins are the majority. Modern pharmacological studies have shown that Polygala saponins have neuroprotective effects on a variety of neurological diseases. Its mechanism of action involves autophagic degradation of misfolded proteins, anti-inflammatory, anti-apoptotic, antioxidative stress and so on. Toxicological studies have shown that Polygala saponins trigger gastrointestinal toxicity, and honey processing and glycosyl disruption of Polygala saponins can effectively ameliorate its gastrointestinal side effect.

CONCLUSION

Polygala saponins are the major bioactive components in plants of the genus Polygala that exhibit therapeutic potential in various neurological diseases. This review provides directions for the future study of Polygala saponins and references for the clinical use of prescriptions containing Radix Polygalae for the treatment of neurological diseases.

The role of Cdk5 in neurological disorders

Neurological disorders are a group of disorders with motor, sensory or cognitive damage, caused by dysfunction of the central or peripheral nervous system. Cyclin-dependent kinases 5 (Cdk5) is of vital significance for the development of the nervous system, including the migration and differentiation of neurons, the formation of synapses, and axon regeneration. However, when the nervous system is subject to pathological stimulation, aberrant activation of Cdk5 will induce abnormal phosphorylation of a variety of substrates, resulting in a cascade signaling pathway, and thus lead to pathological changes. Cdk5 is intimately related to the pathological mechanism of a variety of neurological disorders, such as A-β protein formation in Alzheimer’s disease, mitochondrial fragmentation in cerebral ischemia, and apoptosis of dopaminergic neurons in Parkinson’s disease. It is worth noting that Cdk5 inhibitors have been reported to have neuroprotective effects by inhibiting related pathological processes. Therefore, in this review, we will briefly introduce the physiological and pathological mechanisms of Cdk5 in the nervous system, focusing on the recent advances of Cdk5 in neurological disorders and the prospect of targeted Cdk5 for the treatment of neurological disorders.