Upregulation effects of Tanshinone IIA on the expressions of NeuN, Nissl body, and IκB and downregulation effects on the expressions of GFAP and NF-κB in the brain tissues of rat models of Alzheimer's disease

Raddeanin A isolated from Anemone raddeana Regel improves pathological and cognitive deficits of the mice model of Alzheimer's disease by targeting β-amyloidosis

BACKGROUND

Raddeanin A is a triterpenoid isolated from Anemone raddeana Regel. It exhibits a broad spectrum of biological activities such as anti-tumor and anti-inflammatory, however, its neuroprotective effect in targeting Alzheimer's disease (AD) remains uninvestigated.

PURPOSE

To provide scientific base for the development of novel AD drug by clarifying the neuroprotective effect and molecular mechanisms of raddeanin A in both in vitro and in vivo AD model.

STUDY DESIGN

To confirm the neuroprotective role of raddeanin A in the treatment of AD, its mechanisms and effects on β-amyloidosis and Aβ fibrillation was studied in U87 cells. Besides, the improvement on cognitive deficit, pathological defects, reactive astrocyte clusters, inhibition on neuronal inflammation and apoptosis were further studied in 3 x Tg-AD mice model of AD.

METHODS

Real-time PCR, western blot, dot blot, biolayer interferometry and bioinformatics analysis were used to confirm the in vitro effect and targets of raddeanin A on β-amyloidosis and its associated protein network. A series of experiments including Morris water maze, H&E staining, nissl staining and immunofluorescence analysis were conducted to confirm the protective behavioral effect of raddeanin A in the in vivo AD mice model.

RESULTS

Raddeanin A was identified to reduce β-amyloidosis in U87 cells and 3 x Tg-AD mice model of AD by decreasing level of BACE1, APP, APP-β and Aβ. Raddeanin A improved behavioral, spatial memory and learning ability in the AD mice. In the cortex and hippocampus, raddeanin A improved the morphology and arrangement of neurons, lower the level of reactive astrocyte marker GFAP and apoptotic marker proteins Bax/Bcl2 ratio. Moreover, raddeanin A upregulated the mRNA and protein level of Prkcα in the hippocampus of AD mice whose neuroprotective effect was exerted possibly via the activation of protein kinase C.

CONCLUSION

As a novel natural agent targeting β-amyloidosis, our results provide the first evidence of the multiple in vitro and in vivo neuroprotective effect of raddeanin A, suggesting its potential therapeutic application in preventing or alleviating the symptoms of AD.

Icariin rescues developmental BPA exposure induced spatial memory deficits in rats

Bisphenol A (BPA) has been implicated in cognitive impairment. Icariin is the main active ingredient extracted from Epimedium Herb with protective function of nervous system. However, the potential therapeutic effects of Icariin on spatial memory deficits induced by developmental BPA exposure in Sprague-Dawley rats have not been investigated. This study investigated the therapeutic effect of Icariin (10 mg/kg/day, from postnatal day (PND) 21 to PND 60 by gavage) on spatial memory deficits in rat induced by developmental BPA exposure (1 mg/kg/day, from embryonic to PND 60), demonstrating that Icariin can markedly improve spatial memory in BPA-exposed rat. Furthermore, intra-gastric administration of Icariin could attenuate abnormal hippocampal cell dispersion and loss, improved the dendritic spine density and Nissl bodies. Moreover, Icariin reversed BPA induced reduction of frequency of miniature excitatory postsynaptic currents(mEPSC) and decrease of Vesicular glutamate transporter 1(VGlut1). Collectively, Icariin could effectively rescue BPA-induced spatial memory impairment in male rats by preventing cell loss and reduction of dendritic spines in the hippocampus. In addition, we also found that VGlut1 is a critical target in the repair of BPA-induced spatial memory by Icariin. Thus, Icariin may be a promising therapeutic agent to attenuate BPA-induced spatial memory deficits.

Research Progress on Natural Plant Molecules in Regulating the Blood-Brain Barrier in Alzheimer's Disease

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder. With the aging population and the continuous development of risk factors associated with AD, it will impose a significant burden on individuals, families, and society. Currently, commonly used therapeutic drugs such as Cholinesterase inhibitors, N-methyl-D-aspartate antagonists, and multiple AD pathology removal drugs have been shown to have beneficial effects on certain pathological conditions of AD. However, their clinical efficacy is minimal and they are associated with certain adverse reactions. Furthermore, the underlying pathological mechanism of AD remains unclear, posing a challenge for drug development. In contrast, natural plant molecules, widely available, offer multiple targeting pathways and demonstrate inherent advantages in modifying the typical pathologic features of AD by influencing the blood-brain barrier (BBB). We provide a comprehensive review of recent in vivo and in vitro studies on natural plant molecules that impact the BBB in the treatment of AD. Additionally, we analyze their specific mechanisms to offer novel insights for the development of safe and effective targeted drugs as well as guidance for experimental research and the clinical application of drugs for the prevention and treatment of AD.

Inflammatory signaling pathways in the treatment of Alzheimer's disease with inhibitors, natural products and metabolites (Review)

The intricate nature of Alzheimer's disease (AD) pathogenesis poses a persistent obstacle to drug development. In recent times, neuroinflammation has emerged as a crucial pathogenic mechanism of AD, and the targeting of inflammation has become a viable approach for the prevention and management of AD. The present study conducted a comprehensive review of the literature between October 2012 and October 2022, identifying a total of 96 references, encompassing 91 distinct pharmaceuticals that have been investigated for their potential impact on AD by inhibiting neuroinflammation. Research has shown that pharmaceuticals have the potential to ameliorate AD by reducing neuroinflammation mainly through regulating inflammatory signaling pathways such as NF‑κB, MAPK, NLRP3, PPARs, STAT3, CREB, PI3K/Akt, Nrf2 and their respective signaling pathways. Among them, tanshinone IIA has been extensively studied for its anti‑inflammatory effects, which have shown significant pharmacological properties and can be applied clinically. Thus, it may hold promise as an effective drug for the treatment of AD. The present review elucidated the inflammatory signaling pathways of pharmaceuticals that have been investigated for their therapeutic efficacy in AD and elucidates their underlying mechanisms. This underscores the auspicious potential of pharmaceuticals in ameliorating AD by impeding neuroinflammation.

Standardized extract of Glehnia Littoralis abrogates memory impairment and neuroinflammation by regulation of CREB/BDNF and NF-κB/MAPK signaling in scopolamine-induced amnesic mice model

Mild cognitive impairment is a typical symptom of early Alzheimer's disease (AD). Glehnia littoralis (G. littoralis), a medicinal halophyte plant commonly used to treat strokes, has been shown to possess some therapeutic qualities. In this study, we investigated the neuroprotective and anti-neuroinflammatory effects of a 50% ethanol extract of G. littoralis (GLE) on lipopolysccharide (LPS)-stimulated BV-2 cells and scopolamine-induced amnesic mice. In the in vitro study, GLE treatment (100, 200, and 400 µg/mL) markedly attenuated the translocation of NF-κB to the nucleus concomitantly with the significant mitigation of the LPS-induced production of inflammatory mediators, including NO, iNOS, COX-2, IL-6, and TNF-α. In addition, the GLE treatment suppressed the phosphorylation of MAPK signaling in the LPS-stimulated BV-2 cells. In the in vivo study, mice were orally administered with the GLE (50, 100, and 200 mg/kg) for 14 days, and cognitive loss was induced via the intraperitoneal injection of scopolamine (1 mg/kg) from 8 to 14 days. We found that GLE treatment ameliorated memory impairment and simultaneously improved memory function in the scopolamine-induced amnesic mice. Correspondingly, GLE treatment significantly decreased the AChE level and upregulated the protein expression of neuroprotective markers, such as BDNF and CREB, as well as Nrf2/HO-1 and decreased the levels of iNOS and COX-2 in the hippocampus and cortex. Furthermore, GLE treatment attenuated the increased phosphorylation of NF-κB/MAPK signaling in the hippocampus and cortex. These results suggest that GLE has a potential neuroprotective activity that may ameliorate learning and memory impairment by regulating AChE activity, promoting CREB/BDNF signaling, and inhibiting NF-κB/MAPK signaling and neuroinflammation.

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.

Electroacupuncture at Zusanli ameliorates the autistic-like behaviors of rats through activating the Nrf2-mediated antioxidant responses

OBJECTIVE

Emerging evidence suggests that acupuncture plays a neuroprotective role in autism. This study aimed to explore the effect of electroacupuncture at Zusanli (ST36) on autistic-like behaviors and the underlying mechanism.

METHOD

Pregnant rats were administered with valproic acid (VPA) on gestational day 12.5 to induce an autism spectrum disorder (ASD) model. The pups were given electroacupuncture at ST36 daily from postnatal day (PND) 28-48. On PND28, the adenoviral vector containing small interfering RNA Nrf2 (Ad-siRNA-Nrf2) was injected into the prefrontal cortex of rats. The behavioral analysis was performed on PND 44-48. On PND48, the animals were euthanized and the brains were collected for further detection. Nissl staining was performed to detect neuronal viability. The biochemical markers of oxidative stress were subsequently measured.

RESULT

Electroacupuncture at ST36 ameliorated the locomotor activity, social behavior, spatial learning and memory and repetitive behavior compared with ASD rats. It was notable that the electroacupuncture decreased oxidative stress markers in the tissues of prefrontal cortex, enhanced translocation of nuclear factor erythroid2-related factor2 (Nrf2) from cytoplasm to nucleus, and up-regulated the levels of NADP(H) quinone oxidoreductase (NQO1) and heme oxygenase (HO-1). However, these effects induced by electroacupuncture at ST36 were abolished after injection of Ad-siRNA-Nrf2.

CONCLUSION

These data suggested that electroacupuncture at ST36 protected nerve function in ASD rats through Nrf2 activation and the antioxidant response.

Medication Rules in Herbal Medicine for Mild Cognitive Impairment: A Network Pharmacology and Data Mining Study

Background

Although traditional Chinese medicine (TCM) has good efficacy in the treatment of mild cognitive impairment (MCI), especially memory improvement and safety, its substance basis and intervention mechanism are particularly complex and unknown. Therefore, based on network pharmacology and data mining, this study aims to explore the rules, active ingredients and mechanism of TCM in the treatment of MCI.

Methods

By searching the GeneCard, OMIM, DisGeNET and DrugBank databases, we obtained the critical targets associated with MCI. We matched the components and herbs corresponding to the important targets in the TCMSP platform. Using Cytoscape 3.7.2 software, we constructed a target-component-herb network and conducted a network topology analysis to obtain the core components and herbs. Molecular docking was used to preliminarily analyze and predict the binding activities and main binding combinations of the core targets and components. Based on the analysis of the properties, flavor and meridian distribution of herbs, the rules of herbal therapy for MCI were summarized.

Results

Twenty-eight critical targets were obtained after the screening. Using the TCMSP platform, 492 components were obtained. After standardization, we obtained 387 herbs. Based on the target-composition-herb network analysis, the core targets were ADRB2, ADRA1B, DPP4, ACHE and ADRA1D. According to the screening, the core ingredients were beta-sitosterol, quercetin, kaempferol, stigmasterol and luteolin. The core herbs were matched to Danshen, Yanhusuo, Gancao, Gouteng and Jiangxiang. It was found that the herbs were mainly warm in nature, pungent in taste and liver and lung in meridian. The molecular docking results showed that most core components exhibited strong binding activity to the target combination regardless of the in or out of network combination.

Conclusion

The results of this study indicate that herbs have great potential in the treatment of MCI. This study provides a reference and basis for clinical application, experimental research and new drug development of herbal therapy for MCI.

Ginsenoside Rg1 improves Alzheimer's disease by regulating oxidative stress, apoptosis, and neuroinflammation through Wnt/GSK-3β/β-catenin signaling pathway

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that can cause cognitive impairment. Ginsenoside Rg1 (Rg1) has a significant neuroprotective effect on animals with memory impairment. However, the mechanism of how Rg1 mediates the Wnt signaling pathway and improves cognitive function by regulating oxidative stress, apoptosis, and neuroinflammation is still unclear. In this study, the spatial memory ability of tree shrews was tested by Morris water maze, the expression levels of amyloid protein (Aβ1-42), ionized calcium-binding adapter molecule 1 (iba-1), nitrotyrosine (NT), and 8-hydroxyguanine (8-OHG) were detected by immunohistochemistry. Subsequently, the activity of catalase (CAT) and the glutathione peroxidase (GSH-Px) was, respectively, measured by the ammonium molybdate method and the 5,5'-dithiobis (2-nitrobenzoic acid). Furthermore, the malondialdehyde (MDA) concentration was determined by the thiobarbituric acid test. Finally, the expression levels of Beta-secretase (BACE1), superoxide dismutase (SOD), BCL2-Associated X (Bax), B-cell lymphoma-2 (Bcl-2), caspase-anti-apoptotic factor Cleaved-caspase-3 (Caspase-3), microtubule-associated proteins 2 (MAP2), Neuronal nuclear antigen (NeuN), as well as the phosphorylation of GSK-3β and β-catenin were detected by Western blot. This study implied that Rg1 reduced the phosphorylation of Tau protein, the deposition of Aβ1-42, and the expression of BACE1. It also showed that Rg1 increased the antioxidant activity of SOD, CAT, GPx, and instead reduced the oxidation products of NT, 8-OHG, and MDA, as wells as the inflammatory factor interleukin-1 and iba-1. It further showed that Rg1 increased the ratio of Bcl-2 to Bax and expression of neuronal markers MAP2 and NeuN, but instead reduced the expression of Caspase-3, GSK-3β, and β-catenin. In conclusion, by regulating the Wnt/GSK-3β/β-catenin signaling pathway, Rg1 of moderate and high dose could alleviate oxidative stress damage, improve neuroinflammation, protect neurons, finally improve the cognitive impairment of the AD tree shrew. This study provides theoretical basis for the Rg1 clinical application in AD.

Tanshinone IIA enhances the ovarian reserve and attenuates ovarian oxidative stress in aged mice

Background

Tanshinone IIA (TSA), a major lipophilic component extracted from the roots of Salvia miltiorrhiza Bunge, has been widely used in China for its various biological activities. However, its effect on ovarian reserve in aged mice was not studied elsewhere.

Objectives

This study aimed to explore the effect of TSA on the ovarian reserve of aged mice as well as young mice. Forty weeks old mice (N = 40) were considered as aged group compared to 4 weeks old mice (N = 40), and these groups were subdivided into four subgroups (N = 10) to receive different doses of TSA (0, 10, 20, and 40 μg/g/day).

Methods

The effect of TSA was evaluated by counting follicular number by histological examination. Basal serum levels of FSH, LH, E2, and anti‐Mullerian hormone (AMH) were measured by ELISA. Moreover, the expression levels of antioxidant genes (CAT, Nrf2, GPX1), gap junction (Cx37), ERK1/2, and Smad5 family gene were examined at both mRNA (qPCR) and protein levels (western blot).

Results

Follicular number, level of AMH and E2, and the expression of CAT, Nrf2, and GPX1 genes increased significantly (p < 0.05) in aged mice administrated with medium (20 μg/g/day) and high (40 μg/g/day) doses of TSA, whereas FSH and LH levels were significantly low compared to low dose (10 μg/g/day) and control (0 μg/g/day) aged subgroups. However, we did not observe any effect of all doses of TSA on young mice.

Conclusions

Administration of TSA with medium and high doses up‐regulates the expression of antioxidative genes, reduces the oxidative injury, increases levels of AMH, and E2 levels that are relatively comparable to those in young mice, and consequently results in a healthy oocyte development.

Microglial activation in Alzheimer's disease: The role of flavonoids and microRNAs

Alzheimer's disease (AD) is the most common form of senile dementia and is characterized by progressive cognitive impairment and neuronal degeneration. Microglial activation is an important pathologic hallmark of AD. During disease progression, microglial cells switch from an alternative or anti-inflammatory and neuroprotective profile (M2) to a classic or proinflammatory and neurotoxic profile (M1). Phenotypically, M1 microglia is characterized by the activation of inflammatory signaling pathways that cause increased expression of proinflammatory genes, including those coding for cytokines and chemokines. This microglia-mediated neuroinflammation contributes to neuronal cell death. Recent studies in microglial cells have shown that a group of plant-derived compounds, known as flavonoids, possess anti-inflammatory properties and therefore exert a neuroprotective effect through regulating microglia activation. Here, we discuss how flavonoids can promote the switch from an inflammatory M1 phenotype to an anti-inflammatory M2 phenotype in microglia and how this represents a valuable opportunity for the development of novel therapeutic strategies to blunt neuroinflammation and boost neuronal recovery in AD. We also review how certain flavonoids can inhibit neuroinflammation through their action on the expression of microglia-specific microRNAs (miRNAs), which also constitute a key therapeutic approach in different neuropathologies involving an inflammatory component, including AD. Finally, we propose novel targets of microglia-specific miRNAs that may be considered for AD treatment.

Effects of Moringa oleifera in Two Independents Formulation and as Neuroprotective Agent Against Scopolamine-Induced Memory Impairment in Mice

Background

The cognitive deficit has frequently been found in the elderly population. Several studies have shown that every single part of Moringa oleifera, including leaves, roots, and seeds, has abundant micronutrients, such as flavonoids, which improve the neurobehavioral capacity. However, herb parts that display optimal neuropharmacological properties remain unknown.

Objective

We investigate whether M. oleifera seed oil (MOO) or aqueous M. oleifera leaves extracts (MOEs) may ameliorate memory impairment in mice induced with scopolamine (Sco). Additionally, the phytochemical analyses of those two independent formulations were analyzed.

Methods

In this study, 2 ml/kg body weight (BW) of MOO and 500 mg/kg BW of MOE were orally administered to the mice for 28 days, followed by intraperitoneal injection of Sco (1 mg/kg) at the day 22–28 to induce cognitive impairment in those mice.

Results

The Sco group showed memory retention impairment represented by the Y-maze and novel object recognition tests, significant enhancement of acetylcholine esterase (AChE) activity in hippocampus tissue (p < 0.0001), and increased the level of total antioxidant capacity (TAOC) in serum. Interestingly, the Sco-induced memory defect was improved and completely blunted the AChE exacerbation in Sco+MOO-treated mice (p < 0.0001), although the TAOC level was comparable among the groups. Mechanistically, both tropomyosin receptor kinase B (TrkB), as a brain-derived neurotrophic factor-receptor, and nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-κB) protein expressions were enhanced with the hippocampus isolated from the Sco group. Nonetheless, pretreatment with MOO only, but not with MOE, ameliorated the enhanced protein expression levels of TrkB and NF-κB (p < 0.05 and p = 0.09, respectively).

Conclusion

Our data reveal that MOO is preferable to MOE as a neuroprotective as evidenced by improving memory impairment. This effect, at least in part, through inhibiting the AChE and NF-κB activities and modulating the TrkB expression level.

Zinc finger E-Box binding homeobox 2 (ZEB2)-induced astrogliosis protected neuron from pyroptosis in cerebral ischemia and reperfusion injury

Ischemia injury can cause cell death or impairment of neuron and astrocytes, and thus induce loss of nerve function. central nervous systems injury induces an aberrant activation of astrocytes called astrogliosis. Pyroptosis, which is a kind of programmed cell death, was proved play an important role in ischemia injury. Zinc Finger E-Box Binding Homeobox 2 (ZEB2) promoted neuron astrogliosis, which play a protected role in neuron regeneration. However, its precise mechanism remains unclear. This study investigated the mechanism of ZEB2 on astrogliosis and neuron regeneration after cerebral ischemia reperfusion condition. To confirm our hypothesis, Neurons and astrocytes were isolated from fetal Sprague Dawley rats, in vivo Middle Cerebral Artery Occlusion/reperfusion (MCAO/R) rat model and in vitro oxygen-glucose deprivation/reperfusion (OGD/R)-treated astrocytes and neurocytes model were constructed. Our results showed that ZEB2 was expressed in nucleus of astrocyte and upregulated after OGD/R induction, ZEB2 promoted astrogliosis. Further upregulation of ZEB2 promoted the astrogliosis, which promoted neuron proliferation and regeneration by decreased pyroptosis. Moreover, this finding was further confirmed in vivo MCAO/R rat model. Overexpression of ZEB2 promoted astrogliosis, which decreased infarct volume and accumulated recovery of neurological function by alleviated pyroptosis. This finding revealed that ZEB2 was a regulator of the astrogliosis after ischemia/reperfusion injury, and then astrogliosis promoted neuron regeneration via decreased neuron pyroptosis. Therefore, ZEB2 may be a potential therapeutic target for ischemia/reperfusion injury.

Active constituent of Polygala tenuifolia attenuates cognitive deficits by rescuing hippocampal neurogenesis in APP/PS1 transgenic mice

BACKGROUND

Alzheimer's disease (AD) is the most common dementia worldwide, and there is still no satisfactory drug or therapeutic strategy. Polygala tenuifolia is a traditional Chinese medicine with multiple neuroprotective effects. In present study, we investigated the effects of three active constituents [3,6'-disinapoyl sucrose (DISS), onjisaponin B (OB) and tenuifolin (TEN)] of Polygala tenuifolia (PT) on the proliferation and differentiation of neural stem cells (NSCs) to identify the potential active constituent of PT promoting hippocampal neurogenesis.

METHODS

NSCs were isolated from hippocampi of newborn C57BL/6 mice, and transfected with mutant amyloid precursor protein (APP) gene to establish an AD cell model (APP-NSCs). 3-(4,5- Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays were performed, and the proliferation and differentiation of NSCs were assessed by neurosphere formation assay, 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and immunofluorescence (IF) staining analysis. APP/PS1 transgenic mice were administrated with the potential active constituent DISS for 4 weeks. Morris water maze (MWM), Nissl staining assay and IF staining assays were carried out to evaluate the cognitive function, neural damages and hippocampal neurogenesis, respectively.

RESULTS

DISS exerted the optimal ability to strengthen APP-NSCs proliferation and neuronal differentiation, followed by OB and TEN. Furthermore, DISS treatment for 4 weeks strikingly rescued the cognitive deficits, neuronal injures, and neurogenesis disorder in adult APP/PS1 transgenic mice.

CONCLUSIONS

Our findings demonstrated that DISS is the constituent of PT that triggers the most potent increase of hippocampal neurogenesis in our mouse model of AD.

Electroacupuncture Improves Clearance of Amyloid-β through the Glymphatic System in the SAMP8 Mouse Model of Alzheimer's Disease

Background

Memory loss and cognitive impairment characterize the neurodegenerative disorder, Alzheimer's disease (AD). Amyloid-β (Aβ) is the key factor that triggers the course of AD, and reducing the deposition of Aβ in the brain has been considered as a potential target for the treatment of AD. In clinical and animal studies, electroacupuncture (EA) has been shown to be an effective treatment for AD. In recent years, substantial evidence has accumulated suggesting the important role of the glymphatic system in Aβ clearance.

Objective

The purpose of this study was to explore whether EA modifies the accumulation of Aβ through the glymphatic system and may thus be applied to alleviate cognitive impairments.

Methods

Seven-month-old SAMP8 mice were randomized into a control group (Pc) and an electroacupuncture group (Pe). Age-matched SAMR1 mice were used as normal controls (Rc). Mice in the Pe group were stimulated on Baihui (GV20) and Yintang (GV29) for 10 min and then pricked at Shuigou (GV26) for ten times. EA treatment lasted for 8 weeks. In each week, EA would be applied once a day for the first five consecutive days and ceased at the remaining two days. After EA treatment, Morris water maze (MWM) test was used to evaluate the cognitive function; HE and Nissl staining was performed to observe the brain histomorphology; ELISA, contrast-enhanced MRI, and immunofluorescence were applied to explore the mechanisms underlying EA effects from Aβ accumulation, glymphatic system function, reactivity of astrocytes, and AQP4 polarization, respectively.

Results

This EA regime could improve cognition and alleviate neuropathological damage to brain tissue. And EA treatment might reduce Aβ accumulation, enhance paravascular influx in the glymphatic system, inhibit the reactivity of astrocytes, and improve AQP4 polarity.

Conclusion

EA treatment might reduce Aβ accumulation from the brain via improving clearance performance of the glymphatic system and thereby alleviating cognitive impairment.

Allium hookeri Extracts Improve Scopolamine-Induced Cognitive Impairment via Activation of the Cholinergic System and Anti-Neuroinflammation in Mice

Allium hookeri (AH) is a medicinal food that has been used in Southeast Asia for various physiological activities. The objective of this study was to investigate the activation of the cholinergic system and the anti-neuroinflammation effects of AH on scopolamine-induced memory impairment in mice. Scopolamine (1 mg/kg body weight, i.p.) impaired the performance of the mice on the Y-maze test, passive avoidance test, and water maze test. However, the number of error actions was reduced in the AH groups supplemented with leaf and root extracts from AH. AH treatment improved working memory and avoidance times against electronic shock, increased step-through latency, and reduced the time to reach the escape zone in the water maze test. AH significantly improved the cholinergic system by decreasing acetylcholinesterase activity, and increasing acetylcholine concentration. The serum inflammatory cytokines (IL-1β, IL-6, and IFN-γ) increased by scopolamine treatment were regulated by the administration of AH extracts. Overexpression of NF-κB signaling and cytokines in liver tissue due to scopolamine were controlled by administration of AH extracts. AH also significantly decreased Aβ and caspase-3 expression but increased NeuN and ChAT. The results suggest that AH extracts improve cognitive effects, and the root extracts are more effective in relieving the scopolamine-induced memory impairment. They have neuroprotective effects and reduce the development of neuroinflammation.

A vicious cycle of neuropathological, cognitive and behavioural sequelae of repeated opioid overdose

In the midst of an escalating U.S. opioid crisis, the immediate focus of public health interventions is on fatal overdose prevention. Few studies, however, have sought to examine the long-term health consequences of exposure to repeated nonfatal opioid overdose. We reviewed recent literature to examine three corresponding downstream health outcomes of repeated overdose: a) neurodegenerative processes; b) cognition and memory; and c) overdose risk behaviours. We found a remarkable congruency among available biochemical and cognitive data on how nonfatal overdose precipitates various pathological feedforward and feedback loops that affect people who use opioids for years to come. We found however that downstream behavioural implications of neurodegenerative and cognitive sequelae are less studied despite being most proximal to an overdose. Findings point to a vicious cycle of nonfatal overdose leading to neurodegeneration - closely resembling Alzheimer Disease - that results in cognitive decline that in turn leads to potentially reduced adherence to safe drug use behaviours. The collected evidence not only brings into the focus the long-term health consequences of nonfatal overdose from the perspectives of biology, neuroscience, and public health, but also creates new cross-disciplinary context and awareness in the research and public health community that should benefit people at risk.

Injection of Anti-proBDNF Attenuates Hippocampal-Dependent Learning and Memory Dysfunction in Mice With Sepsis-Associated Encephalopathy

Sepsis-associated encephalopathy (SAE) is a risk factor for cognitive and memory dysfunction; however, the mechanism remains unclear. Brain-derived neurotrophic factor (BDNF) was reported to have a positive effect on cognition and emotion regulation, but the study of its precursor, proBDNF, has been limited. This study aimed to elucidate the effects and associated mechanisms of hippocampal proBDNF in a lipopolysaccharide (LPS)-induced SAE mouse model. In this study, we found that the mice exhibited cognitive dysfunction on day 7 after LPS injection. The expression of proBDNF and its receptor, p75^NTR, was also increased in the hippocampus, while the levels of BDNF and its receptor, TrkB, were decreased. A co-localization study showed that proBDNF and p75^NTR were mainly co-localized with neurons. Furthermore, LPS treatment reduced the expression of NeuN, Nissl bodies, GluR4, NR1, NR2A, and NR2B in the hippocampus of SAE mice. Furthermore, an intrahippocampal or intraperitoneal injection of anti-proBDNF antibody was able to ameliorate LPS-induced cognitive dysfunction and restore the expression of NeuN, Nissl bodies, GluR4, NR1, NR2A, NR2B, and PSD95. These results indicated that treatment with brain delivery by an intrahippocampal and systemic injection of mAb-proBDNF may represent a potential therapeutic strategy for treating patients with SAE.

Tanshinones and their Derivatives: Heterocyclic Ring-Fused Diterpenes of Biological Interest

The available scientific literature regarding tanshinones is very abundant, and after its review, it is noticeable that most of the articles focus on the properties of tanshinone I, cryptotanshinone, tanshinone IIA, sodium tanshinone IIA sulfonate and the dried root extract of Salvia miltiorrhiza (Tan- Shen). However, although these products have demonstrated important biological properties in both in vitro and in vivo models, their poor solubility and bioavailability have limited their clinical applications. For these reasons, many studies have focused on the search for new pharmaceutical formulations for tanshinones, as well as the synthesis of new derivatives that improve their biological properties. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2015) on tanshinones in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we offer an update on the last five years of new research on these quinones, focusing on their synthesis, biological activity on noncommunicable diseases and drug delivery systems, to support future research on its clinical applications.

Expression of Cntn1 is regulated by stress and associated with anxiety and depression phenotypes

In recent years, our understanding of neural circuits associated with depression has increased. Although inherited factors are known to influence individual differences in the risk for this disorder, it has been difficult to identify specific genes that moderate circuit functions affecting depression. Genome-wide association studies have identified genetic variants of Cntn1 that are linked to major depressive disorders. Cntn1, a subset of the neural cell adhesion protein and immunoglobulin supergene family, participates in cell contact formation and axonal growth control and plays a role in degenerative and inflammatory disorders. However, neuronal substrates that mediate Cntn1 action on depression-like phenotypes and involved mechanisms are unclear. Here, we exploited chronic unpredictable stress (CUS) exposure and found that CUS treatment significantly increased hippocampal Cntn1 messenger RNA and protein expression in both mice and rats, but not in the medial prefrontal cortex, which presented a region-specific regulation. Using an adeno-associated virus-based approach to directly overexpress Cntn1 via stereotactic injection, we demonstrated that Cntn1 overexpression in the hippocampus triggered anxiety- and depression-like phenotypes in addition to microglia activation or phagocytosis in the hippocampus, resulting in upregulation of pro-inflammatory cytokine (IL1α, IL6, and Ccl2) mRNA expression and downregulation of anti-inflammatory cytokine (IL4 and CD206) mRNA expression, determined using real-time quantitative PCR, thus impairing hippocampal immature neurons in the dentate gyrus, determined using immunohistochemical staining for doublecortin, a specific marker for immature neurons. Collectively, our results identified Cntn1 as a novel risk gene involved in regulating anxiety and depression via functional actions in the hippocampus that is correlated with microglial activation or phagocytosis and reduced hippocampal immature neurons. These results may provide a better understanding of the pathophysiological mechanisms underlying the risk of depression-related disorders.

Effects of 1.5 and 4.3 GHz microwave radiation on cognitive function and hippocampal tissue structure in Wistar rats

Previous studies have shown that single-frequency microwave radiation can lead to cognitive decline in rats. However, few studies have focused on the combined effects of irradiation with different frequencies of microwaves. Our research aimed to investigate the effects of 1.5 GHz and 4.3 GHz microwave radiation, singly and in combination, on cognitive function and hippocampal tissue structure in rats. A total of 140 male Wistar rats were randomly divided into 4 groups: the S group (sham radiation group), L10 group (10 mW/cm² 1.5 GHz group), C10 group (10 mW/cm² 4.3 GHz band group) and LC10 group (10 mW/cm² 1.5 and 4.3 GHz multi-frequency radiation group). For 1–28 days after microwave radiation, we analyzed the average escape latency for the Morris water maze task, electroencephalograms, change in hippocampal tissue structure and ultrastructure, content of the Nissl body in the hippocampus, and activities of lactate dehydrogenase and succinate dehydrogenase. Compared to the S group, all exposure groups showed varying degrees of learning and memory decline and hippocampal structural damage. The results showed that 1.5 GHz and 4.3 GHz microwave radiation was able to induce cognitive impairment and hippocampal tissue damage in rats and combined radiation with both frequencies caused more serious injuries, but none of these damaging effects varied with microwave frequency.

Tanshinone IIA: A phytochemical as a promising drug candidate for neurodegenerative diseases

Tanshinones, lipophilic diterpenes isolated from the rhizome of Salvia miltiorrhiza, have diverse pharmacological activities against human ailments including neurological diseases. In fact, tanshinones have been used to treat heart diseases, stroke, and vascular diseases in traditional Chinese medicine. During the last decade, tanshinones have been the most widely studied phytochemicals for their neuroprotective effects against experimental models of cerebral ischemia and Alzheimer's diseases. Importantly, tanshinone IIA, mostly studied tanshinone for biological activities, is recently reported to attenuate blood-brain barrier permeability among stroke patients, suggesting tanshinone IIA as an appealing therapeutic candidate for neurological diseases. Tanshinone I and IIA are also effective in experimental models of Parkinson's disease, Multiple sclerosis, and other neuroinflammatory diseases. In addition, several experimental studies suggested the pleiotropic neuroprotective effects of tanshinones such as anti-inflammatory, antioxidant, anti-apoptotic, and BBB protectant further value aiding to tanshinone as an appealing therapeutic strategy in neurological diseases. Therefore, in this review, we aimed to compile the recent updates and cellular and molecular mechanisms of neuroprotection of tanshinone IIA in diverse neurological diseases.

Interaction of NF-κB and Wnt/β-catenin Signaling Pathways in Alzheimer's Disease and Potential Active Drug Treatments

The most important neuropathological features of Alzheimer's disease (AD) are extracellular amyloid-β protein (Aβ) deposition, tau protein hyperphosphorylation and activation of neurometabolic reaction in the brain accompanied by neuronal and synaptic damage, and impaired learning and memory function. According to the amyloid cascade hypothesis, increased Aβ deposits in the brain to form the core of the senile plaques that initiate cascade reactions, affecting the synapses and stimulating activation of microglia, resulting in neuroinflammation. A growing number of studies has shown that NF-κB and Wnt/β-catenin pathways play important roles in neurodegenerative diseases, especially AD. In this review, we briefly introduce the connection between neuroinflammation-mediated synaptic dysfunction in AD and elaborated on the mechanism of these two signaling pathways in AD-related pathological changes, as well as their interaction. Based on our interest in natural compounds, we also briefly introduce and conduct preliminary screening of potential therapeutics for AD.

Tanshinone IIA: A Review of its Anticancer Effects

Tanshinone IIA (Tan IIA) is a pharmacologically lipophilic active constituent isolated from the roots and rhizomes of the Chinese medicinal herb Salvia miltiorrhiza Bunge (Danshen). Tan IIA is currently used in China and other neighboring countries to treat patients with cardiovascular system, diabetes, apoplexy, arthritis, sepsis, and other diseases. Recently, it was reported that tan IIA could have a wide range of antitumor effects on several human tumor cell lines, but the research of the mechanism of tan IIA is relatively scattered in cancer. This review aimed to summarize the recent advances in the anticancer effects of tan IIA and to provide a novel perspective on clinical use of tan IIA.

Does a hypoxic injury from a non-fatal overdose lead to an Alzheimer Disease?

Long term consequence of non-fatal overdose in people who use opioids are not well understood. The intermittent exposure to non-fatal overdose leads to a tauopathy that is often accompanied by abrogated neuroprotective response, abnormal amyloid processing and other pathologies. The scope and limitations of available literature are discussed including neuropathologies associated with opioid and overdose exposures, contributing comorbidities and proteinopathies. Contrasting postmortem data of overdose victims with animal models of opioid neuropathologies and hypoxic injury paints a picture distinct from other proteinopathies as well as effects of moderate opioid exposure. Furthermore the reported biochemical changes and potential targets for therapeutic intervention were mapped pointing to underlying imbalance between tau kinases and phosphatases that is characteristic of Alzheimer Disease.

Critical Review of the Alzheimer's Disease Non-Transgenic Models: Can They Contribute to Disease Treatment?

Alzheimer's disease (AD) is a growing neurodegenerative disease without effective treatments or therapies. Despite the use of different approaches and an extensive variety of genetic amyloid based models, therapeutic strategies remain elusive. AD is characterized by three main pathological hallmarks that include amyloid-β plaques, neurofibrillary tangles, and neuroinflammatory processes; however, many other pathological mechanisms have been described in the literature. Nonetheless, the study of the disease and the screening of potential therapies is heavily weighted toward the study of amyloid-β transgenic models. Non-transgenic models may aid in the study of complex pathological states and provide a suitable complementary alternative to evaluating therapeutic biomedical and intervention strategies. In this review, we evaluate the literature on non-transgenic alternatives, focusing on the use of these models for testing therapeutic strategies, and assess their contribution to understanding AD. This review aims to underscore the need for a shift in preclinical research on intervention strategies for AD from amyloid-based to alternative, complementary non-amyloid approaches.

Effect of atorvastatin on AGEs-induced injury of cerebral cortex via inhibiting NADPH oxidase -NF-κB pathway in ApoE-/- mice

Advanced glycation end products (AGEs) are a group of modified proteins and/or lipids with damaging potential. AGEs-RAGE pathway plays a critical role to induce neurodegenerative encephalopathy. Statins can reduce the expression of AGEs-induced AGEs receptor (RAGE) in the aorta. It is not clear whether statins have potential benefits on AGEs-induced cognitive impairment. In this study, the effects of atorvastatin (ATV) on inflammation and oxidation stress in the cerebral cortex were investigated, and the underlying mechanisms were explored. Apolipoprotein E (ApoE)^-/- male mice were divided into four groups: control, AGEs, AGEs + ALT711 (Alagebrium chloride) and AGEs + ATV. β-amyloid (Aβ) formation in the cerebral cortex was assessed through Congo red staining and the functional state of neurons was evaluated by Nissl's staining. Immunostaining was performed to assess the accumulation of AGEs in the cerebral cortex. The expressions of mRNA and protein of RAGE, Nuclear factor kappa B (NF-κB) p65 and Nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) p47phox were detected by real-time polymerase chain reaction (PCR) and western blot. There were significant increases in AGEs deposit, Aβ formation, and the expressions of RAGE, NF-κB p65, and NADPH oxidase p47phox, and a decrease Nissl body in AGEs group compared with control group. ALT711 group recovered above change compared with AGEs group. Atorvastatin reduced Aβ formation and suppressed AGEs-induced expressions of NF-κB p65 and NADPH oxidase p47phox. Atorvastatin has little effects on AGEs deposit and RAGE expressions. Atorvastatin alleviates AGEs-induced neuronal impairment by alleviating inflammation and oxidative stress via inhibiting NADPH oxidase-NF-κB pathway.

Tanshinone IIA attenuates neuroinflammation via inhibiting RAGE/NF-κB signaling pathway in vivo and in vitro

Background

Glial activation and neuroinflammation play a crucial role in the pathogenesis and development of Alzheimer’s disease (AD). The receptor for advanced glycation end products (RAGE)-mediated signaling pathway is related to amyloid beta (Aβ)-induced neuroinflammation. This study aimed to investigate the neuroprotective effects of tanshinone IIA (tan IIA), a natural product isolated from traditional Chinese herbal Salvia miltiorrhiza Bunge, against Aβ-induced neuroinflammation, cognitive impairment, and neurotoxicity as well as the underlying mechanisms in vivo and in vitro.

Methods

Open-field test, Y-maze test, and Morris water maze test were conducted to assess the cognitive function in APP/PS1 mice. Immunohistochemistry, immunofluorescence, thioflavin S (Th-S) staining, enzyme-linked immunosorbent assay (ELISA), real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and western blotting were performed to explore Aβ deposition, synaptic and neuronal loss, microglial and astrocytic activation, RAGE-dependent signaling, and the production of pro-inflammatory cytokines in APP/PS1 mice and cultured BV2 and U87 cells.

Results

Tan IIA treatment prevented spatial learning and memory deficits in APP/PS1 mice. Additionally, tan IIA attenuated Aβ accumulation, synapse-associated proteins (Syn and PSD-95) and neuronal loss, as well as peri-plaque microgliosis and astrocytosis in the cortex and hippocampus of APP/PS1 mice. Furthermore, tan IIA significantly suppressed RAGE/nuclear factor-κB (NF-κB) signaling pathway and the production of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) in APP/PS1 mice and cultured BV2 and U87 cells.

Conclusions

Taken together, the present results indicated that tan IIA improves cognitive decline and neuroinflammation partly via inhibiting RAGE/NF-κB signaling pathway in vivo and in vitro. Thus, tan IIA might be a promising therapeutic drug for halting and preventing AD progression.

Pharmacological basis of tanshinone and new insights into tanshinone as a multitarget natural product for multifaceted diseases

Drug development has long included the systematic exploration of various resources. Among these, natural products are one of the most important resources from which novel agents are developed due to the multiple pharmacologic effects of these natural products on diseases. Tanshinone, a representative natural product, is the main compound extracted from the dried root and rhizome of Salvia miltiorrhiza Bge. Research on tanshinone began in the early 1930s. With the in-depth investigation of an increasing number of identified analogs, tanshinone has demonstrated a wide variety of bioactivities and contradicted the saying, 'You can't teach an old dog new tricks'. This review is focused on the pharmacological action of tanshinone and status of research on tanshinone in recent years. The mechanism of tanshinone has also drawn much attention, with the findings of representative targets and pathways of tanshinone. The most recent studies have comprehensively shown that tanshinone can be used to treat leukemia and solid carcinoma, protect against cardiovascular and cerebrovascular diseases, and alleviate liver- and kidney-related diseases, among its other effects. Multiple signaling pathways, including antiproliferative, antiapoptotic, anti-inflammatory, and antioxidative stress pathways, are involved in its actions.

Traditional Chinese Medicine for Alzheimer's Disease and Other Cognitive Impairment: A Review

Cognitive impairment (CI) refers to the dysfunction of memory, language, visual space, execution, calculation, understanding, and judgment in one or more aspects. With global aging, CI will become prevalent worldwide. At present, there is no effective cure for CI. However, Nobel laureate Tu Youyou's research on artemisinin has inspired Chinese researchers to focus on traditional Chinese herbs (TCHs) for the treatment of CI. Traditional Chinese Medicine (TCM) has led to a theory for an independent CI system. The pathogenesis of such impairment involves deficiency, phlegm, and stagnation and involves a range of organs, including the brain, kidneys, heart, liver, and spleen. Our current understanding of the etiology and pathogenesis of this condition has led to the realization that TCHs can improve cognitive dysfunction. Clinical research has shown that TCHs can improve the neuropsychological scale score of patients, the TCM symptom score, and the patient's quality of life. Research has also suggested that TCHs can retard Aβ deposits and tauopathy, regulate the metabolism of cholinergic neurotransmitters, and so on. However, due to their complexity, little is known of the safety and efficacy of TCHs in patients with CI. It is likely that we will be able to identify the precise mechanisms associated with the action of TCHs in such patients due to the integration of multiple technologies. This paper summarizes the pharmacokinetics, curative effect, and mechanisms of action of traditional Chinese herbs in order to provide a scientific basis for the improvement of cognitive dysfunction by TCHs.

5-HT1AR alleviates Aβ-induced cognitive decline and neuroinflammation through crosstalk with NF-κB pathway in mice

The 5-hydroxytryptamine (5-HT) receptor is significant for the regulation of mood and memory. However, the role of 5-HT1AR in β-Amyloid protein (Aβ)-induced cognitive decline, neuroinflammation and the possible mechanism remains elusive. Thus, we aimed to evaluate the effects of 5-HT1AR on Aβ-induced learning and memory decline and neuroinflammation in mice. Novel object recognition and Morris water maze tests were performed to observe learning and memory behavior in mice. Protein levels of Iba1, GFAP, MAP2, TNF-α, Tβ4, C-fos, IKK-β, IKB-α, NF-κBp65, phospho-NF-κBp65 in the hippocampus were examined by immunostaining or western blotting. Aβ1-42-treatment inducing learning and memory decline was shown in novel object recognition and Morris water maze tests; neuroinflammation shown in immunostaining. Our study found out that 5-HT1AR inhibitor WAY100635 showed significant improvement in Aβ-induced learning and memory decline. Moreover, WAY100635 decreases levels of Iba1, GFAP, and TNF-α in the hippocampus, which were related to neuroinflammation. While treatment with 5-HT1AR agonist 8-OH-DPAT or ERK inhibitor U0126 exerted no effects or even aggravated Aβ-induced learning and memory decline. In addition, WAY100635 could downregulate phospho-NF-κB in the hippocampus of Aβ1-42-injected mice. These results provide new insight into the mechanism, for 5-HT1AR in Aβ-induced cognitive impairments through crosstalk with the NF-κB signaling pathway. Our data indicated that WAY100635 was involved in the protective effects against neuroinflammation and improvement of learning and memory in Alzheimer's disease.

Tanshinone IIA Alleviates CCL2-Induced Leaning memory and Cognition Impairment in Rats: A Potential Therapeutic Approach for HIV-Associated Neurocognitive Disorder

Chemokine CC motif ligand 2 (CCL2) is one of the most recognized proinflammatory chemokines, and the expression of CCL2 in the cerebrospinal fluid of patients infected with HIV-1 is significantly higher than that of healthy people. As such, it is seen as an important cause of HIV-associated neurocognitive disorder (HAND). Our previous investigation has confirmed the pathological role of CCL2 in mediating brain damage leading to cognitive dysfunction. Currently, however, research on therapeutic drugs for the central nervous system targeting CCL2 is very limited. Our present study used brain stereotactic technology to induce cognitive impairment in rats by injecting CCL2 (5 ng) into the bilateral hippocampus. To investigate the protective effect and mechanism of Tanshinone IIA (25, 50, 75 mg/kg/d) on CCL2-induced learning memory and cognitive impairment in rats, we performed the Morris water maze (MWM) and novel object recognition tests (NORT) on the rats. The results showed that Tanshinone IIA significantly alleviated CCL2-induced learning memory and cognitive dysfunction. Further studies on the hippocampal tissue of the rats revealed that Tanshinone IIA treatment significantly increased the activity of SOD and GSH-Px while the level of MDA decreased compared to the model group. Additionally, the relative expression of apoptosis-associated genes caspase-3, caspase-8, and caspase-9 and inflammation-associated genes IL-1β and IL-6 in Tanshinone IIA-treated rats was lower than that in model rats. Finally, we confirmed hippocampal neuron loss and apoptosis by Nissl staining and TdT-mediated dUTP Nick end labeling (TUNEL). Taken together, these data imply that Tanshinone IIA can ameliorate CCL2-induced learning memory and cognitive impairment by impacting oxidative stress, inflammation, and apoptosis. Tanshinone IIA may be a potential therapeutic agent for the treatment of HAND.

Neuroprotection mediated by natural products and their chemical derivatives

Neuronal injuries can lead to various diseases such as neurodegenerative diseases, stroke, trauma, ischemia and, more specifically, glaucoma and optic neuritis. The cellular mechanisms that regulate neuronal death include calcium influx and calcium overload, excitatory amino acid release, oxidative stress, inflammation and microglial activation. Much attention has been paid to the effective prevention and treatment of neuroprotective drugs by natural products. This review summarizes the neuroprotective aspects of natural products, extracted from Panax ginseng, Camellia sinensis, soy and some other plants, and some of their chemical derivatives. Their antioxidative and anti-inflammatory action and their inhibition of apoptosis and microglial activation are assessed. This will provide new directions for the development of novel drugs and strategies to treat neurodegenerative diseases.

Beneficial Effects of Sagacious Confucius' Pillow Elixir on Cognitive Function in Senescence-Accelerated P8 Mice (SAMP8) via the NLRP3/Caspase-1 Pathway

Sagacious Confucius' Pillow Elixir (SCPE) is a traditional Chinese medicine that is mainly used for cognitive impairment in aging; however, the underlying mechanisms remain unclear. Aging is one of the most important pathogenic factors leading to inflammation and pyroptosis in the hippocampus, which may be a potential mechanism in elderly patients with cognitive impairment. Here, we examined whether SCPE could improve cognitive impairment in SAMP8 mice by reducing hippocampal inflammation and pyroptosis. Seven-month-old senescence-accelerated P8 mice (SAMP8) received SCPE (2.3 g/kg/day; 4.6 g/kg/day; 9.2 g/kg/day) for 28 days. Cognitive function and morphometric examinations were performed followed by water maze testing, hematoxylin-eosin staining, Congo red staining, toluidine blue staining, and TUNEL analysis of hippocampal CA1 and CA3 regions. Escape latency increased and times across platforms decreased in SAMP8 mice; however, both of them were normalized by SCPE after 28 days. Aging caused significant pyroptosis in hippocampal CA1 and CA3 regions, as evidenced by neuronal degeneration and necrosis, amyloid deposition, and decreased Nissl body amounts after cognitive impairment, which were greatly improved by SCPE. SCPE reduced serum IL-1β, IL-6, IL-18, and TNF-α levels and reduced hippocampal NLRP3, ASC, caspase-1, GSDM-D, IL-1β, IL-6, IL-18, and Aβ expression. Thus, SCPE exerts an antipyroptotic effect in aging, mainly by suppressing the NLRP3/caspase-1 signaling pathway.

Changes in Expression Profiles Revealed by Transcriptomic Analysis in Peripheral Blood Mononuclear Cells of Alzheimer's Disease Patients

Alzheimer's disease (AD) is an age-related neurodegenerative pathology associated with accumulation of DNA damage. Inflammation and cell cycle alterations seem to be implicated in the pathogenesis of AD, although the molecular mechanisms have not been thoroughly elucidated to date. The aim of the present study was to evaluate whether peripheral blood mononuclear cells (PBMCs) of AD patients display alterations in gene expression profiles, focusing on finding markers that might improve the diagnosis of AD. Blood samples were collected from 22 AD patients and 13 healthy individuals to perform genome-wide mRNA expression. We found 593 differentially expressed genes in AD compared to controls, from which 428 were upregulated, and 165 were downregulated. By performing a gene set enrichment analysis, we observed pathways involved in inflammation, DNA damage response, cell cycle, and neuronal processes. Moreover, functional annotation analyses indicated that differentially expressed genes are strongly related to pathways associated with the cell cycle and the immune system. The results were compared with those of an independent study on hippocampus samples, and a number of genes in common between both studies were identified as potential peripheral biomarkers for AD, including DUSP1, FOS, SLC7A2, RGS1, GFAP, CCL2, ANGPTL4, and SSPN. Taken together, our results demonstrate that PBMCs of AD patients do present alterations in gene expression profiles, and these results are comparable to those previously reported in the literature for AD neurons, supporting the hypothesis that blood peripheral mononuclear cells express molecular changes that occur in the neurons of AD patients.

Sodium tanshinone IIA sulfonate: A review of pharmacological activity and pharmacokinetics

Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivate of tanshinone IIA (Tan IIA) which is an active lipophilic constitute of Chinese Materia Medica Salvia miltiorrhiza Bge. (Danshen). STS presents multiple pharmacological activities, including anti-oxidant, anti-inflammation and anti-apoptosis, and has been approved for treatment of cardiovascular diseases by China State Food and Drug Administration (CFDA). In this review, we comprehensively summarized the pharmacological activities and pharmacokinetics of STS, which could support the further application and development of STS. In the recent decades, numerous experimental and clinical studies have been conducted to investigate the potential treatment effects of STS in various diseases, such as heart diseases, brain diseases, pulmonary diseases, cancers, sepsis and so on. The underlying mechanisms were most related to anti-oxidative and anti-inflammatory effects of STS via regulating various transcription factors, such as NF-κB, Nrf2, Stat1/3, Smad2/3, Hif-1α and β-catenin. Iron channels, including Ca²⁺, K⁺ and Cl^- channels, were also the important targets of STS. Additionally, we emphasized the differences between STS and Tan IIA despite the interchangeable use of Tan IIA and STS in many previous studies. It is promising to improve the efficacy and reduce side effects of chemotherapeutic drug by the combination use of STS in canner treatment. The application of STS in pregnancy needs to be seriously considered. Moreover, the drug-drug interactions between STS and other drugs needs to be further studied as well as the complications of STS.

Danshen: a phytochemical and pharmacological overview

Danshen, the dried root or rhizome of Salvia miltiorrhiza Bge., is a traditional and folk medicine in Asian countries, especially in China and Japan. In this review, we summarized the recent researches of Danshen in traditional uses and preparations, chemical constituents, pharmacological activities and side effects. A total of 201 compounds from Danshen have been reported, including lipophilic diterpenoids, water-soluble phenolic acids, and other constituents, which have showed various pharmacological activities, such as anti-inflammation, anti-oxidation, anti-tumor, anti-atherogenesis, and anti-diabetes. This article intends to provide novel insight information for further development of Danshen, which could be of great value to its improvement of utilization.

Computational insights into β-site amyloid precursor protein enzyme 1 (BACE1) inhibition by tanshinones and salvianolic acids from Salvia miltiorrhiza via molecular docking simulations

The rhizome of Salvia miltiorrhiza has emerged as a rich source of natural therapeutic agents, and its several compounds are supposed to exhibit favorable effects on Alzheimer's disease (AD). The present work investigate the anti-AD potentials of 12 tanshinones, three salvianolic acids and three caffeic acid derivatives from S. miltiorrhiza via the inhibition of β-site amyloid precursor protein cleaving enzyme 1 (BACE1). Among the tested compounds, deoxyneocryptotanshinone (1), salvianolic acid A (13) and salvianolic acid C (15) displayed good inhibitory effect on BACE1 with IC₅₀ values of 11.53 ± 1.13, 13.01 ± 0.32 and 9.18 ± 0.03 μM, respectively. Besides this, enzyme kinetic analysis on BACE1 revealed 13, a competitive type inhibitor while 1 and 15 showed mixed-type inhibition. Furthermore, molecular docking simulation displayed negative binding energies (AutoDock 4.2.6 = -10.0 to -7.1 kcal/mol) of 1, 13, and 15 for BACE1, indicating these compounds bound tightly to the active site of the enzyme with low energy and high affinity. The results of the present study clearly demonstrate that S. miltiorrhiza and its constituents have potential anti-AD activity and can be used as a therapeutic agent for the treatment of AD.

Changed expressions of N-methyl-d-aspartate receptors in the brains of rats and primary neurons exposed to high level of fluoride

Expressions of N-methyl-d-aspartic acid receptors (NMDARs) in the brains of rats and primary neurons exposed to high fluoride were investigated. Sprague-Dawley rats were divided randomly into a fluorosis group (50ppm fluoride in the drinking water for 6 months) and controls (<0.5ppm fluoride) and the offspring from these rats sacrificed on postnatal days 1, 7, 14, 21 and 28. The primary cultured neurons from the hippocampus of neonatal rats were treated with 5 and 50ppm fluoride for 48h. NMDAR subunits at protein or mRNA levels were quantified by Western blotting or real-time PCR. The phosphorylated calmodulin-protein kinase II (CaMKII) was determined by Western blotting, concentration of Ca²⁺ in neurons by laser confocal microscopy and apoptosis by flow cytometry. In the brains of adult rats and pups as well as in primary neurons exposed to high fluoride, the mRNAs encoding GluN1 and GluN2B subunits and the corresponding proteins were elevated, the GluN3A lowered and the GluN2A unchanged. In addition, the level of phosphor-CaMKII was reduced, and Ca²⁺ influx and apoptosis enhanced in the brains of rats and cultured neurons exposed to high fluoride. The results indicate that such modifications may involve brain damage induced by chronic fluorosis.

Reduction of NF-κB (p65) in Scrapie-Infected Cultured Cells and in the Brains of Scrapie-Infected Rodents

Transcription factor NF-κB functions as a pleiotropic regulator of target genes controlling physiological function as well as pathological processes of many different diseases, including some neurodegenerative diseases. However, the role of NF-κB in the pathogenesis of prion disease remains ambiguous. In this study, the status of NF-κB (p65) in a prion-infected cell line SMB-S15 was first evaluated. Significantly lower levels of p65 and the phosphorylated form of p65 (p-p65) were detected in SMB-S15 cells, compared with its normal partner cell line SMB-PS. Markedly slower responses of the NF-κB system to the stimulation of TNF-α were observed in SMB-S15 cells. Removal of PrP^Sc replication in SMB-S15 cells rescued the expression and activity of NF-κB. However, overexpression of p65 in SMB-S15 cells did not influence the propagation of PrP^Sc. Moreover, significant decline of p65 level was also observed in the brain tissues of mice infected with the lysates of SMB-S15 cells and hamsters infected with scrapie agent 263K at terminal stage. Immunofluorescence assays (IFAs) on brain sections from either normal or scrapie-infected rodents revealed colocalization of p65 with neuronal nuclear (NeuN) protein positive cells but not with glial fibrillary acidic protein (GFAP) positive cells. Assays of the agents involving in the regulation of NF-κB showed down-regulated phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB/Akt) both in SMB-S15 cells and in the brains of scrapie-infected rodents. Those data indicate a remarkable repression of the classical NF-κB pathway during prion infection both in vitro and in vivo. The alteration of NF-κB (p65) shows close association with the replication and accumulation of PrP^Sc in the cells.

Study on dose-dependent, frequency-dependent, and accumulative effects of 1.5 GHz and 2.856 GHz microwave on cognitive functions in Wistar rats

Many studies have revealed the cognitive decline induced by microwave radiation. However, the systematic study on dose-dependent, frequency-dependent and accumulative effects of microwave exposure at different frequencies was lacking. Here, we studied the relationship between the effects and the power and frequency of microwave and analyzed the accumulative effects of two different frequency microwaves with the same average power density. After microwave radiation, declines in spatial learning and memory and fluctuations of brain electric activities were found in the 10 mW/cm2 single frequency exposure groups and accumulative exposure groups. Meanwhile, morphological evidences in hippocampus also supported the cognitive dysfunction. Moreover, the decrease of Nissl contents in neurons indicated protein-based metabolic disorders in neurons. By detecting the key functional proteins of cholinergic transmitter metabolism, cytokines, energy metabolism and oxidative stress in the hippocampus, we found that microwave could lead to multiple metabolic disorders. Our results showed that microwave-induced cognitive decline was largely determined by its power rather than frequency. Injury effects were also found in accumulative exposure groups. We particularly concerned about the safety dose, injury effects and accumulative effects of microwaves, which might be very valuable in the future.

Tanshinone IIA ameliorates apoptosis of myocardiocytes by up-regulation of miR-133 and suppression of Caspase-9

To explore the potential protective effect of Tanshinone ⅡA on myocardial cell apoptosis and elucidate the underlying molecular mechanisms. The rat heart cell H9c2 was treated by either H₂O₂ or doxorubicin (DOX) to mimic oxidative stress and DNA damage conditions in vivo. Cell growth was monitored by optical microscope observation or CCK-8 counting kit. The relative expression of miR-133 and U6 snoRNA was semi-quantitated by RT-PCR or real-time PCR. Cell apoptosis was analyzed by flow cytometry with Annexin V/PI double staining. The microRNA binding sites were predicted by online bioinformatics tools. The regulatory effect of miR-133 on caspase-9 was measured by luciferase reporter assay. Apoptosis pathway factors were analyzed by immunoblotting. Our data demonstrated that Tanshinone ⅡA significantly ameliorated myocardial apoptosis induced by either H₂O₂ or DOX. The protective effect was likely mediated by up-regulation of miR-133. We further identified Caspase-9 as the target of miR-133. Tanshinone ⅡA treatment significantly reversed down-regulation of miR-133 under harsh conditions and in turn suppressed evoking of Caspase-9 and related apoptotic effectors, which consequently contributed to the improvement of myocardial injury. In conclusion, Tanshinone ⅡA ameliorated myocardial apoptosis via restoration of miR-133 and suppression Caspase-9 signaling cascade, which underlies its well-proven clinical benefit and warrants larger scale clinical applications.

Arginine vasopressin ameliorates spatial learning impairments in chronic cerebral hypoperfusion via V1a receptor and autophagy signaling partially

Chronic cerebral hypoperfusion (CCH) is a major factor contributing to neurological disorders and cognitive decline. Autophagy activation is believed to provide both beneficial and detrimental roles during hypoxic/ischemic cellular injury. Although arginine vasopressin (AVP) has been strongly involved in many behaviors, especially in learning and memory, the effects of AVP on CCH and their molecular mechanisms remain unclear. Here, to investigate whether there was neuroprotective effects of AVP on CCH through V1a receptor (an AVP receptor) signaling, permanent bilateral carotid arteries occlusion (two vessel occlusion, 2VO) was used to establish a rat model of CCH, and hypertonic saline (5.3%) was injected intraperitoneally to induce the secretion of AVP. Results showed that hypertonic saline effectively alleviated spatial learning and memory deficit, enhanced synaptic plasticity of CA3-CA1 hippocampal synapses, upregulated N-methyl-d-aspartate receptor subunit 2B (NR2B) and postsynaptic density protein 95 (PSD-95) surface expressions, reduced oxidative stress and increased Nissl bodies in 2VO model rats. These phenomena were significantly decreased by V1a receptor antagonist SR49059. Interestingly, hypertonic saline also upregulated autophagy in the hippocampus of 2VO rats partly through V1a receptor. These findings imply that AVP has a beneficial role for the treatment of cognitive impairments partly through V1a receptor signaling in CCH, which is possibly related to improving synaptic plasticity by promoting NR2B and PSD-95 externalization and by enhancing autophagy.

Toxic effect of acrylamide on the development of hippocampal neurons of weaning rats

Although numerous studies have examined the neurotoxicity of acrylamide in adult animals, the effects on neuronal development in the embryonic and lactational periods are largely unknown. Thus, we examined the toxicity of acrylamide on neuronal development in the hippocampus of fetal rats during pregnancy. Sprague-Dawley rats were mated with male rats at a 1:1 ratio. Rats were administered 0, 5, 10 or 20 mg/kg acrylamide intragastrically from embryonic days 6–21. The gait scores were examined in pregnant rats in each group to analyze maternal toxicity. Eight weaning rats from each group were also euthanized on postnatal day 21 for follow-up studies. Nissl staining was used to observe histological change in the hippocampus. Immunohistochemistry was conducted to observe the condition of neurites, including dendrites and axons. Western blot assay was used to measure the expression levels of the specific nerve axon membrane protein, growth associated protein 43, and the presynaptic vesicle membrane specific protein, synaptophysin. The gait scores of gravid rats significantly increased, suggesting that acrylamide induced maternal motor dysfunction. The number of neurons, as well as expression of growth associated protein 43 and synaptophysin, was reduced with increasing acrylamide dose in postnatal day 21 weaning rats. These data suggest that acrylamide exerts dose-dependent toxic effects on the growth and development of hippocampal neurons of weaning rats.

Tanshinones and mental diseases: from chemistry to medicine

The prevalence of mental diseases, especially neurodegenerative disorders, is ever-increasing, while treatment options for such disorders are limited and insufficient. In this scarcity of available medication, it is a feasible strategy to search for potential drugs among natural compounds, such as those found in plants. One such plant source is the root of Chinese sage, Salvia miltiorrhiza Bunge (Labiatae), which contains several compounds reported to possess neuroprotective activities. The most important of these compounds are tanshinones, which have been reported to possess ameliorative activity against a myriad of mental diseases such as Alzheimer’s disease, cerebral ischemia/reperfusion injury, and glioma, along with promoting neuronal differentiation and manifesting antinociceptive and anticonvulsant outcomes. This review offers a critical evaluation of the utility of tanshinones to treat mental illnesses, and sheds light on the underlying mechanisms through which these naturally occurring compounds confer neuroprotection.