The neuroprotective effects of tanshinone IIA on β-amyloid-induced toxicity in rat cortical neurons

Exploring the Therapeutic Potential of BBB-Penetrating Phytochemicals With p38 MAPK Modulatory Activity in Addressing Oxidative Stress-Induced Neurodegenerative Disorders, With a Focus on Alzheimer's Disease

Oxidative stress plays an important role in the occurrence of neurodegenerative diseases. Previous studies indicate a strong connection between oxidative stress, inappropriate activation of the p38 MAPK signaling pathway, and the pathogenesis of neurodegenerative diseases. Although antioxidant therapy is a valid strategy to alleviate these problems, the most important limitation of this approach is the ineffectiveness of drug administration due to the limited permeability of the BBB. Therefore, BBB-penetrating p38 MAPK modulators with proper antioxidant capacity could be useful in preventing/reducing the complications of neurodegenerative disorders. The current manuscript aims to review the therapeutic capabilities of some recently reviewed naturally occurring p38 MAPK inhibitors in the management of neurodegenerative problems such as Alzheimer's disease. In data collection, we tried to use more recent studies published in high-quality journals indexed in databases Scopus, Web of Science, PubMed, and so on, but no specific time frame was considered due to the nature of the study. Our evaluations indicate that natural compounds tanshinones, protoberberines, pinocembrin, osthole, rhynchophylline, oxymatrine, schisandrin, piperine, paeonol, ferulic acid, 6-gingerol, obovatol, and trolox have significant potential for use as supplements/adjuvants in the reduction of neurodegenerative-related problems. Our findings emphasize the usefulness of BBB-penetrating phytochemicals with p38 MAPK modulatory activity as potential therapeutic options against neurodegenerative disorders. Of course, the proper use of these compounds depends on considering their toxicity/safety profile and pharmacokinetic characteristics as well as the clinical conditions of users.

UBC Gene Family Analysis in Salvia castanea and Roles of ScUBC2/5 Genes under Abiotic Stress

Salvia castanea Diels, a relative of the medicinal plant Salvia miltiorrhiza Bunge, belongs to the genus Salvia and family Lamiaceae. Ubiquitin-conjugating enzyme E2 (UBC) is an important ubiquitin-binding enzyme in protein ubiquitination. This study aimed to analyze the regulatory role of UBC genes, particularly ScUBC2/5, on the growth and adaptation of S. castanea to extreme environments including cold or drought stress. We identified nine UBC genes in S. castanea and found that these genes were extremely stable and more highly expressed in the roots than other tissues. This suggested that UBC genes might play a role in promoting root adaptation to cold and dry environments. Further analysis of UBC gene expression in hairy roots under cold (4 °C) and UV stress also confirmed their importance under stress. The contents of tanshinone and salvianolic acid in hairy roots with the overexpression of ScUBC2/5 were increased compared to non-transgenic wild type, and the cold and UV resistance of hairy roots was increased compared with that of wild type. Together, these findings highlighted the role of ScUBC2/5 in enhancing secondary metabolite accumulation and regulation in response to cold and ultraviolet stress in S. castanea, providing a new perspective for genetic improvement in its phytochemistry.

Exploiting Natural Niches with Neuroprotective Properties: A Comprehensive Review

Natural products from mushrooms, plants, microalgae, and cyanobacteria have been intensively explored and studied for their preventive or therapeutic potential. Among age-related pathologies, neurodegenerative diseases (such as Alzheimer's and Parkinson's diseases) represent a worldwide health and social problem. Since several pathological mechanisms are associated with neurodegeneration, promising strategies against neurodegenerative diseases are aimed to target multiple processes. These approaches usually avoid premature cell death and the loss of function of damaged neurons. This review focuses attention on the preventive and therapeutic potential of several compounds derived from natural sources, which could be exploited for their neuroprotective effect. Curcumin, resveratrol, ergothioneine, and phycocyanin are presented as examples of successful approaches, with a special focus on possible strategies to improve their delivery to the brain.

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

Effects and mechanisms of tanshinone IIA on PTSD-like symptoms

BACKGROUND

In recent years, Salvia miltiorrhiza and its active substances have remarkably progressed in treating central neurological disorders. Tanshinone IIA (TSA) is an active ingredient derived from the rhizome of Salvia miltiorrhiza that has been found to alleviate the symptoms of several psychiatric illnesses. Post-traumatic stress disorder (PTSD) is a mental disorder that results after experiencing a serious physical or psychological injury. The currently used drugs are not satisfactory for the treatment of PTSD. However, it has been reported that TSA can improve PTSD-like symptoms like learning and memory, cognitive disorder, and depression through multi-target regulation.

PURPOSE

This paper discusses the ameliorative effects of TSA on PTSD-like symptoms and the possible mechanisms of action in terms of inhibition of neuronal apoptosis, anti-neuroinflammation, and anti-oxidative stress. Based on the pathological changes and clinical observations of PTSD, we hope to provide some reference for the clinical transformation of Chinese medicine in treating PTSD.

METHODS

A large number of literatures on tanshinone in the treatment of neurological diseases and PTSD were retrieved from online electronic PubMed and Web of Science databases.

CONCLUSION

TSA is a widely studied natural active ingredient against mental illness. This review will contribute to the future development of TSA as a new clinical candidate drug for improving PTSD-like symptoms.

Tanshinone IIA inhibited intermittent hypoxia induced neuronal injury through promoting autophagy via AMPK-mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic intermittent hypoxia (CIH) is the primary pathophysiological process of obstructive sleep apnea (OSA) and is closely linked to neurocognitive dysfunction. Tanshinone IIA (Tan IIA) is extracted from Salvia miltiorrhiza Bunge and used in Traditional Chinese Medicine (TCM) to improve cognitive impairment. Studies have shown that Tan IIA has anti-inflammatory, anti-oxidant, and anti-apoptotic properties and provides protection in intermittent hypoxia (IH) conditions. However, the specific mechanism is still unclear.

AIM OF THE STUDY

To assess the protective effect and mechanism of Tan IIA treatment on neuronal injury in HT22 cells exposed to IH.

MATERIALS AND METHODS

The study established an HT22 cell model exposed to IH (0.1% O₂ 3 min/21% O₂ 7 min for six cycles/h). Cell viability was determined using the Cell Counting Kit-8, and cell injury was determined using the LDH release assay. Mitochondrial damage and cell apoptosis were observed using the Mitochondrial Membrane Potential and Apoptosis Detection Kit. Oxidative stress was assessed using DCFH-DA staining and flow cytometry. The level of autophagy was assessed using the Cell Autophagy Staining Test Kit and transmission electron microscopy (TEM). Western blot was used to detect the expressions of the AMPK-mTOR pathway, LC3, P62, Beclin-1, Nrf2, HO-1, SOD2, NOX2, Bcl-2/Bax, and caspase-3.

RESULTS

The study showed that Tan IIA significantly improved HT22 cell viability under IH conditions. Tan IIA treatment improved mitochondrial membrane potential, decreased cell apoptosis, inhibited oxidative stress, and increased autophagy levels in HT22 cells under IH conditions. Furthermore, Tan IIA increased AMPK phosphorylation and LC3II/I, Beclin-1, Nrf2, HO-1, SOD2, and Bcl-2/Bax expressions, while decreasing mTOR phosphorylation and NOX2 and cleaved caspase-3/caspase-3 expressions.

CONCLUSION

The study suggested that Tan IIA significantly ameliorated neuronal injury in HT22 cells exposed to IH. The neuroprotective mechanism of Tan IIA may mainly be related to inhibiting oxidative stress and neuronal apoptosis by activating the AMPK/mTOR autophagy pathway under IH conditions.

Tanshinone IIA suppresses burning incense-induced oxidative stress and inflammatory pathways in astrocytes

The burning incense (BI) behavior could be widely observed in Asia families. Incense sticks are often believed to be made from natural herbs and powders, and to have minimal impact on human health; however, there is limited research to support this claim. The current study aimed to identify the components of BI within the particulate matter 2.5 µm (PM_2.5) range and explore if BI has bio-toxicity effects on rat astrocytes (CTX-TNA2). The study also examined the protective effects and underlying molecular mechanisms of tanshinone IIA, a primary lipid-soluble compound found in the herb danshen (Salvia miltiorrhiza Bunge), which has been shown to benefit the central nervous system. Results showed that despite the differences in BI components compared to the atmospheric particulate matter (PM) standards, BI still had a bio-toxicity on astrocytes. BI exposure caused early and late apoptosis, reactive oxygen species (ROS) production, MAPKs (JNK, p38, and ERK), and Akt signaling activation, and inflammation-related proteins (cPLA2, COX-2, HO-1, and MMP-9) increases. Our results further exhibit that the tanshinone IIA pre-treatment could significantly avoid the BI-induced apoptosis and inflammatory signals on rat astrocytes. These findings suggest that BI exposure may cause oxidative stress in rat astrocytes and increase inflammation-related proteins and support the potential of tanshinone IIA as a candidate for preventing BI-related adverse health effects.

Neuroprotective Effects of Geopung-Chunghyuldan Based on Its Salvianolic Acid B Content Using an In Vivo Stroke Model

BACKGROUND

Geopung-Chunghyuldan (GCD) has neuroprotective properties. Salviae miltiorrhizae Radix plays an essential role in GCD's effect. The Salviae miltiorrhizae Radix marker compound is salvianolic acid B; however, its content is not uniform among samples. This study aimed to evaluate the neuroprotective effects of GCD based on salvianolic acid B content.

METHODS

The neuroprotective effects of GCD based on the salvianolic acid B content were evaluated by measuring infarct volume 24 h after permanent middle cerebral artery occlusion in an in vivo stroke model. For the experimental group, each GCD was administered immediately before surgery. The control groups were administered distilled water and aspirin (30 mg/kg) in the same way. The salvianolic acid B content in five types of Salviae Miltiorrhizae Radix (two Chinese and three Korean regions) based on different cultivation regions was analyzed by high-performance liquid chromatography.

RESULTS

Three samples met the Korean and Chinese Pharmacopeia standards for salvianolic acid B. However, two samples did not. GCDs with high salvianolic acid B showed marked neuroprotective effects compared to the control groups, whereas GCDs with low salvianolic acid B did not.

CONCLUSIONS

The salvianolic acid B content of Salviae miltiorrhizae Radix affects the neuroprotection effect of GCD. Stable, raw Salviae miltiorrhizae Radix is essential for GCD homogenization.

Tanshinone IIA loaded chitosan nanoparticles decrease toxicity of β-amyloid peptide in a Caenorhabditis elegans model of Alzheimer's disease

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases that characterized by the accumulation of β-amyloid peptide (Aβ). Overexpressions of Aβ could induce oxidative stress that might be a key insult to initiate the cascades of Aβ accumulation. As a result, anti-oxidative stress and attenuating Aβ accumulation might be one promising intervention for AD treatment. Tanshinone IIA (Tan IIA), a major component of lipophilic tanshinones in Danshen, is proven to be effective in several diseases, including AD. Due to the poor solubility in water, the clinical application of Tan IIA was limited. Therefore, a great number of nanoparticles were designed to overcome this issue. In the current study, we choose chitson as delivery carrier to load Tanshinone IIA (CS@Tan IIA) and explore the protective effects of CS@Tan IIA on the CL2006 strain, a transgenic C. elegans of AD model organism. Compared with Tan IIA monomer, CS@Tan IIA could significantly prolong the lifespan and attenuate the AD-like symptoms, including reducing paralysis and the Aβ deposition by inhibiting the oxidative stress. The mechanism study showed that the protection of CS@Tan IIA was attenuated by knockdown of daf-16 gene, but not skn-1. The results indicated that DAF-16/SOD-3 pathway was required in the protective effects of CS@Tan IIA. Besides DAF-16/SOD-3 pathway, the Tan IIA-loaded CS nanoparticles might protect the C. elegans against the AD insults via promoting autophagy. All the results consistently suggested that coating by chitosan could improve the solubility of Tan IIA and effectively enhance the protective effects of Tan IIA on AD, which might provide a potential drug loading approach for the hydrophobic drugs as Tan IIA.

Regulation of mitochondrial dysfunction induced cell apoptosis is a potential therapeutic strategy for herbal medicine to treat neurodegenerative diseases

Neurodegenerative disease is a progressive neurodegeneration caused by genetic and environmental factors. Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD) are the three most common neurodegenerative diseases clinically. Unfortunately, the incidence of neurodegenerative diseases is increasing year by year. However, the current available drugs have poor efficacy and large side effects, which brings a great burden to the patients and the society. Increasing evidence suggests that occurrence and development of the neurodegenerative diseases is closely related to the mitochondrial dysfunction, which can affect mitochondrial biogenesis, mitochondrial dynamics, as well as mitochondrial mitophagy. Through the disruption of mitochondrial homeostasis, nerve cells undergo varying degrees of apoptosis. Interestingly, it has been shown in recent years that the natural agents derived from herbal medicines are beneficial for prevention/treatment of neurodegenerative diseases via regulation of mitochondrial dysfunction. Therefore, in this review, we will focus on the potential therapeutic agents from herbal medicines for treating neurodegenerative diseases via suppressing apoptosis through regulation of mitochondrial dysfunction, in order to provide a foundation for the development of more candidate drugs for neurodegenerative diseases from herbal medicine.

Insights into the plateau adaptation of Salvia castanea by comparative genomic and WGCNA analyses

INTRODUCTION

Salvia castanea, a wild plant species is adapted to extreme Qinghai-Tibetan plateau (QTP) environments. It is also used for medicinal purposes due to high ingredient of tanshinone IIA (T-IIA). Despite its importance to Chinese medicinal industry, the mechanisms associated with secondary metabolites accumulation (i.e. T-IIA and rosmarinic acid (RA)) in this species have not been characterized. Also, the role of special underground tissues in QTP adaptation of S. castanea is still unknown.

OBJECTIVES

We explored the phenomenon of periderm-like structure in underground stem center of S. castanea with an aim to unravel the molecular evolutionary mechanisms of QTP adaptation in this species.

METHODS

Morphologic observation and full-length transcriptome of S. castanea plants were conducted. Comparative genomic analyses of S. castanea with other 14 representative species were used to reveal its phylogenetic position and molecular evolutionary mechanisms. RNA-seq and WGCNA analyses were applied to understand the mechanisms of high accumulations of T-IIA and RA in S. castanea tissues.

RESULTS

Based on anatomical observations, we proposed a "trunk-branches" developmental model to explain periderm-like structure in the center of underground stem of S. castanea. Our study suggested that S. castanea branched off from cultivated Danshen around 16 million years ago. During the evolutionary process, significantly expanded orthologous gene groups, 24 species-specific and 64 positively selected genes contributed to morphogenesis and QTP adaptation in S. castanea. RNA-seq and WGCNA analyses unraveled underlying mechanisms of high accumulations of T-IIA and RA in S. castanea and identified NAC29 and TGA22 as key transcription factors.

CONCLUSION

We proposed a "trunk-branches" developmental model for the underground stem in S. castanea. Adaptations to extreme QTP environment in S. castanea are associated with accumulations of high secondary metabolites in this species.

Mesenchymal stem cells after the proprocessing of tanshinone IIA attenuate cognitive deficits and oxidative stress injury in an amyloid β-peptide (25-35)-induced rodent model of Alzheimer's disease

OBJECTIVES

To verify whether mesenchymal stem cells cocultured with tanshinone IIA may ameliorate Alzheimer's disease by inhibiting oxidative stress.

METHODS

Sixty male Sprague-Dawley rats were randomly divided into 4 groups named Sham, Aβ25-35, mesenchymal stem cells, and mesenchymal stem cells (tanshinone IIA). The rats were treated according to different groups. The neurobehavioral performance of Sprague-Dawley rats was evaluated via Morris water maze test. Histological changes were checked via hematoxylin-eosin staining. The levels of total antioxidant activity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and malondialdehyde in hippocampus were assayed by ELISA kit. The levels of Aβ, p-tau/tau, and p-AMP-activated protein kinase/AMP-activated protein kinase in hippocampus were checked by Western blot.

RESULTS

Our research showed that the injection of mesenchymal stem cells (tanshinone IIA) into the hippocampus alleviated learning and memory deficits and reduced hippocampal neuronal injury in the Alzheimer's disease rats. Moreover, mesenchymal stem cells (tanshinone IIA) treatment suppressed oxidative stress, attenuated Aβ accumulation reduced Tau hyperphosphorylation, and enhanced the activity of AMP-activated protein kinase in the hippocampus of the Alzheimer's disease rats. However, there were almost no significant difference between the mesenchymal stem cells and Aβ25-35 groups.

CONCLUSIONS

Mesenchymal stem cells (tanshinone IIA) transplantation may be a potential treatment for curing Alzheimer's disease, which may be related to the inhibition of oxidative stress.

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.

Natural products as pharmacological modulators of mitochondrial dysfunctions for the treatments of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder characterized by neuronal loss and cognitive impairment that harshly affect the elderly individuals. Currently, the available anti-AD pharmacological approaches are purely symptomatic to alleviate AD symptoms, and the curative effects of novel anti-AD drugs focused on Aβ target are disappointing. Hence, there is a tremendous need to adjust AD therapeutic targets and discover novel anti-AD agents. In AD, mitochondrial dysfunction gradually triggers neuronal death from different aspects and worsens the occurrence and progress of AD. Consequently, it has been proposed that the intervention of impaired mitochondria represents an attractive breakthrough point for AD treatments. Due to chemical diversity, poly-pharmacological activities, few adverse effects and multiple targeting, natural products (NPs) have been identified as a valuable treasure for drug discovery and development. Multiple lines of studies have scientifically proven that NPs display ameliorative benefits in AD treatment in relation to mitochondrial dysfunction. This review surveys the complicated implications for mitochondrial dysregulation and AD, and then summarizes the potentials of NPs and their underlying molecular mechanisms against AD via reducing or improving mitochondrial dysfunction. It is expected that this work may open the window to speed up the development of innovative anti-AD drugs originated from NPs and improve upcoming AD therapeutics.

Alzheimer's disease treatment: The share of herbal medicines

One of the most frequent forms of dementia in neurological disorders is Alzheimer's disease (AD). It is a chronic neurodegenerative disease characterized by impaired learning and memory. Pathological symptoms as extracellular amyloid-beta (Aβ) plaques and intracellular accumulation of neurofibrillary tangles occur in AD. Due to the aging of the population and increased prevalence of AD, discovery of new therapeutic agents with the highest effectiveness and fewer side effect seems to be necessary. Numerous synthetic medicines such as tacrine, donepezil, galantamine, rivastigmine, memantine, glutathione, ascorbic acid, ubiquinone, ibuprofen, and ladostigil are routinely used for reduction of the symptoms and prevention of disease progression. Nowadays, herbal medicines have attracted popular attention for numerous beneficial effects with little side effects. Lavandula angustifolia, Ginkgo biloba, Melissa officinalis, Crocus sativus, Ginseng, Salvia miltiorrhiza, and Magnolia officinalis have been widely used for relief of symptoms of some neurological disorders. This paper reviews the therapeutic effects of phytomedicines with prominent effects against various factors implicated in the emergence and progression of AD.

Pharmacological Activity and Mechanism of Tanshinone IIA in Related Diseases

Salvia miltiorrhiza: (Danshen) is a significant (traditional Chinese medication) natural remedy, enhancing blood circulation and clear blood stasis. In this view, it is widely used against several heart diseases, eg, cardiomyopathy, arrhythmia, and congenital heart defects. Tanshinone IIA (tan-IIA) is the main fat-soluble component of Salvia miltiorrhiza. Modern pharmacological study shows that tan-IIA has anti-inflammatory and anti-oxidant activities. Tan-IIA induces remarkable cardioprotective effects via enhancing angiogenesis which may serve as an effective treatment against cardiovascular diseases (CVD). There is also evidence that tan-IIA has extensive immunomodulatory effects and plays a significant role in the development and function of immune cells. Tan-IIA reduces the production of inflammatory mediators and restores abnormal signaling pathways via regulating the function and activation of immune cells. It can also regulate signal transduction pathways, ie, TLR/NF-κB pathway and MAPKs/NF-κB pathway, thereby tan-IIA has an anti-inflammatory, anticoagulant, antithrombotic and neuroprotective role. It plays a protective role in the pathogenesis of cardiovascular disorders (ie, atherosclerosis, hypertension) and Alzheimer’s disease. It has also been revealed that tan-IIA has an anti-tumor role by killing various tumor cells, inducing differentiation and apoptosis, and has potential activity against carcinoma progression. In the review of this fact, the tan-IIA role in different diseases and its mechanism have been summarized while its clinical applications are also explored to provide a new perspective of Salvia miltiorrhiza. An extensive study on the mechanism of action of tan-IIA is of great significance for the effective use of Chinese herbal medicine and the promotion of its status and influence on the world.

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.

Tanshinone IIA Suppresses Hypoxia-induced Apoptosis in Medial Vestibular Nucleus Cells Via a Skp2/BKCa Axis

BACKGROUND

The aim of the present study was to investigate the protective effects of Tanshinone IIA (Tan IIA) on hypoxia-induced injury in the medial vestibular nucleus (MVN) cells.

METHODS

An in vitro hypoxia model was established using MVN cells exposed to hypoxia. The hypoxia-induced cell damage was confirmed by assessing cell viability, apoptosis and expression of apoptosis-associated proteins. Oxidative stress and related indicators were also measured following hypoxia modeling and Tan IIA treatment, and the genes potentially involved in the response were predicted using multiple GEO datasets.

RESULTS

The results of the present study showed that Tan IIA significantly increased cell viability, decreased cell apoptosis and decreased the ratio of Bax/Bcl-2 in hypoxia treated cells. In addition, hypoxia treatment increased oxidative stress in MVN cells, and treatment with Tan IIA reduced the oxidative stress. The expression of SPhase Kinase Associated Protein 2 (SKP2) was upregulated in hypoxia treated cells, and Tan IIA treatment reduced the expression of SKP2. Mechanistically, SKP2 interacted with large-conductance Ca2+-activated K+ channels (BKCa), regulating its expression, and BKCa knockdown alleviated the protective effects of Tan IIA on hypoxia induced cell apoptosis.

CONCLUSION

The results of the present study suggested that Tan IIA had a protective effect on hypoxia-induced cell damage through its anti-apoptotic and anti-oxidative activity via an SKP2/BKCa axis. These findings suggest that Tan IIA may be a potential therapeutic for the treatment of hypoxia-induced vertigo.

RasGRF1 participates in the protective effect of tanshinone IIA on depressive like behaviors of a chronic unpredictable mild stress induced mouse model

Tanshinone IIA (Tan IIA) is reported to have neuroprotective effects to suppress cell apoptosis of cortical neurons induced by Aβ_25-35 through inhibiting oxidative stress. Nevertheless, few studies have investigated the effects of Tan IIA on depressive disorder. Here, we aimed to measure the effects of Tan IIA on chronic unpredictable mild stress (CUMS) induced mouse model and its underlying mechanism. For 28 days, mice were subjected to CUMS while Tan IIA was administered once daily at doses of 0, 1, 2.5, 5, or 10 mg/kg. CUMS exposure increased depressive-like behaviors, as indicated by increased immobility time in the forced swim and tail suspension tests, decreased sucrose preference in the sucrose preference test, and reduced exploratory behavior in the open field test. All of these behaviors were reversed dose-dependently by Tan IIA treatment. Oxidative stress was determined by measuring malondialdehyde, glutathione peroxidase, and superoxide dismutase activity and total antioxidant capacity. Levels of pro-inflammatory factors IL-1β and IL-18, cAMP response element binding protein and brain derived neurotrophic factor were detected by ELISA and western blot assay, respectively. The results showed that CUMS increased oxidative stress and pro-inflammatory factors and decreased levels of cAMP response element binding protein and brain-derived neurotrophic factor. Tan IIA treatment again reversed these effects. Importantly, RasGRF1 expression increased in CUMS-exposed mice but decreased after Tan IIA administration. Using RasGRF1^-/- mice to determine the role of RasGRF1 in mice exposed to CUMS, we found that knockdown of RasGRF1 reversed the effects of CUMS on mice, just like Tan IIA. These results indicate that Tan IIA may reverse depressive-like behaviors in CUMS-exposed mice by regulating RasGRF1.

Specific Degradation of Endogenous Tau Protein and Inhibition of Tau Fibrillation by Tanshinone IIA through the Ubiquitin-Proteasome Pathway

Alzheimer's disease (AD) is a common neurodegenerative disease which is partly characterized by the aggregation of hyperphosphorylated Tau proteins forming neurofibrillary tangles that promote AD pathogenesis. In this study, we investigated the effects of tanshinone IIA (Tan IIA) isolated from Salvia miltiorrhiza on Tau degradation in the treatment of AD. The results showed that Tan IIA reduced the Tau expression and attenuated Tau phosphorylation in N2a cells, Tau-overexpressing cells, and 3×Tg-AD mouse primary neuron cells. Moreover, Tan IIA increased polyubiquitinated Tau accumulation and induced proteasomal degradation of the Tau protein. Additionally, Tan IIA became bound to the Tau protein and inhibited the formation of heparin-induced Tau fibrils. In summary, Tan IIA can increase polyubiquitinated Tau accumulation and induce the proteasomal degradation of the Tau protein and the binding of Tan IIA to the Tau protein, inhibiting the formation of Tau fibrils. Tan IIA may be further explored as a potential candidate for AD treatment.

Danshen formula granule and salvianic acid A alleviate ethanol-induced neurotoxicity

As a direct neurotoxin, ethanol exposure is associated with nerve damage and dysfunction of central nervous system (CNS) and induced obvious neurotoxicity by increasing the reactive oxygen species (ROS) production, activation of endogenous apoptotic as well as necrotic signals, and other molecular mechanisms. The previous studies had demonstrated that natural herbal medicine offers protective effectiveness on ethanol-induced nerve cell damage. Danshen and its extracts have been known to have an antioxidant property and neuroprotective effects. However, the protective effects of Danshen formula granule and salvianic acid A on ethanol-induced neurotoxicity remain unknown. In this study, we found that the Danshen formula granule and salvianic acid A significantly inhibited the ethanol-induced cell death, blocked LDH release, and reduced dendritic spine loss. Furthermore, the intracellular ROS, MDA production, and ethanol-induced apoptosis were significantly ameliorated with Danshen formula granule and salvianic acid A pretreatment by increasing the antioxidant enzymatic activity of CAT, SOD and GSH-Px, and inhibiting apoptotic pathways. In addition, Danshen formula granule and salvianic acid A pretreatment obviously inhibit the apoptotic pathways by regulating the protein expression of Bcl-2, Bax, and Caspase-3. In conclusion, our data demonstrated that the Danshen formula granule and salvianic acid A provide a significantly protective effectiveness against ethanol-induced neurotoxicity, which might be a potential therapeutic drug for ethanol-induced neurological disorders.

Tanshinone IIA attenuates Aβ-induced neurotoxicity by down-regulating COX-2 expression and PGE2 synthesis via inactivation of NF-κB pathway in SH-SY5Y cells

Amyloid-β (Aβ)-induced neurotoxicity is a major pathological mechanism of Alzheimer's disease (AD). Tanshinone IIA (Tan IIA), extracted from traditional Chinese herb Radix salvia miltiorrhiza, possesses anti-oxidant and anti-inflammatory actions, as well as neuroprotective effects. The present study aims to explore the possible mechanism by which Tan IIA attenuated Aβ-induced neurotoxicity. Exposure of SH-SY5Y cells to different concentrations of Aβ led to neurotoxicity by reducing cell viability, inducing cell apoptosis and increasing neuroinflammation in a dose-dependent manner. Moreover, Aβ treatment promoted cyclooxygenase-2 (COX-2) expression and Prostaglandin E2 (PGE2) secretion, and activated nuclear transcription factor kappa (NF-κB) pathway in SH-SY5Y cells. However, pretreatment of SH-SY5Y cells with Tan IIA prior to Aβ prevented these Aβ-induced cellular events noticeably. These data suggested that Tan IIA exerted its neuroprotective action by alleviating Aβ-induced increase in COX-2 expression and PGE2 secretion via inactivation of NF-κB pathway.

Tanshinone IIA ameliorates cognitive deficits by inhibiting endoplasmic reticulum stress-induced apoptosis in APP/PS1 transgenic mice

Our previous data indicated that tanshinone IIA (tan IIA) improves learning and memory in a mouse model of Alzheimer's disease (AD) induced by streptozotocin via restoring cholinergic function, attenuating oxidative stress and blocking p38 MAPK signal pathway activation. This study aims to estimate whether tan IIA inhibits endoplasmic reticulum (ER) stress-induced apoptosis to prevent cognitive decline in APP/PS1 transgenic mice. Tan IIA (10 mg/kg and 30 mg/kg) was intraperitoneally administered to the six-month-old APP/PS1 mice for 30 consecutive days. β-amyloid (Aβ) plaques were measured by immunohistochemisty and Thioflavin S staining, apoptotic cells were observed by TUNEL, ER stress markers and apoptosis signaling proteins were investigated by western blotting and RT-PCR. Our results showed that tan IIA significantly ameliorates cognitive deficits and improves spatial learning ability of APP/PS1 mice in the nest-building test, novel object recognition test and Morris water maze test. Furthermore, tan IIA significantly reduced the deposition of Aβ plaques and neuronal apoptosis, and markedly prevented abnormal expression of glucose regulated protein 78 (GRP78), initiation factor 2α (eIF2α), inositol-requiring enzyme 1α (IRE1α), activating transcription factor 6 (ATF6), as well as suppressed the activation of C/EBP homologous protein (CHOP) and c-Jun N-terminal kinase (JNK) pathways in the parietal cortex and hippocampus. Moreover, tan IIA induced an up-regulation of the Bcl-2/Bax ratio and down-regulation of caspase-3 protein activity. Taken together, the above findings indicated that tan IIA improves learning and memory through attenuating Aβ plaques deposition and inhibiting ER stress-induced apoptosis. These results suggested that tan IIA might become a promising therapeutic candidate drug against AD.

DNA Methylome and Transcriptome Alterations in High Glucose-Induced Diabetic Nephropathy Cellular Model and Identification of Novel Targets for Treatment by Tanshinone IIA

Diabetic nephropathy (DN) is a diabetes complication that comes from overactivation of Renin-Angiotensin System, excessive pro-inflammatory factors, reactive oxygen species (ROS) overproduction, and potential epigenetic changes. Tanshinone IIA (TIIA), a diterpene quinone phytochemical, has been shown to possess powerful antioxidant, anti-inflammatory, epigenetics, and protective effects against different diseases including DN by inhibiting ROS induced by high glucose (HG). However, epigenomic and transcriptomic study of DN and the protective effect of TIIA are lacking. In this study, next-generation sequencing of RNA and DNA methylation profiles on the potential underlying mechanisms of a DN model in mouse kidney mesangial mes13 cells challenged with HG and treatment with TIIA were conducted. Bioinformatic analysis coupled with Ingenuity Pathway analysis of RNA-seq was performed, and 1780 genes from HG/LG and 1416 genes from TIIA/HG were significantly altered. Several pro-inflammatory pathways like leukotriene biosynthesis and eicosanoid signaling pathways were activated by HG stimulation, while TIIA treatment would enhance glutathione-mediated detoxification pathway to overcome the excess oxidative stress and inflammation triggered by HG. Combination analysis of RNA-seq and Methyl-seq data sets, DNA methylation, and RNA expression of a list of DN associated genes, Nmu, Fgl2, Glo, and Kcnip2, were found to be altered in HG-induced mes13 DN model, and TIIA treatment would effectively restore the alterations. Taken together, these findings provide novel insights into the understanding of how epigenetic/epigenomic modifications could affect the progression of DN and the potential preventive effect of TIIA in DN.

Dementia in China: epidemiology, clinical management, and research advances

China has the largest population of patients with dementia in the world, imposing a heavy burden on the public and health care systems. More than 100 epidemiological studies on dementia have been done in China, but the estimates of the prevalence and incidence remain inconsistent because of the use of different sampling methods. Despite improved access to health services, inadequate diagnosis and management for dementia is still common, particularly in rural areas. The Chinese Government issued a new policy to increase care facilities for citizens older than 65 years, but most patients with dementia still receive care at home. Western medicines for dementia symptoms are widely used in China, but many patients choose Chinese medicines even though they have little evidence supporting efficacy. The number of clinical trials of Chinese and western medicines has substantially increased as a result of progress in research on new antidementia drugs but international multicentre studies are few in number. Efforts are needed to establish a national system of dementia care enhance training in dementia for health professionals, and develop global collaborations to prevent and cure this disease.

Tanshinone IIa protects retinal endothelial cells against mitochondrial fission induced by methylglyoxal through glyoxalase 1

Advanced glycation end products (AGEs) play an important role in the onset of diabetic retinopathy. Therefore, in the current study, we investigate whether and how Tanshinone IIa (Tan IIa) from Salvia miltiorrhiza protects bovine retinal endothelial cells (BRECs) against methylglyoxal (MGO) mediated cell dysfunction. The results showed that MGO reduced cell viability in dose dependent manner. The treatment of Tan IIa (50 μM) significantly improved cell viability induced by MGO in BRECs. MGO increased cellular reactive oxygen species formation and cellular nitric oxide (NO) level; enhanced nox1 and iNOS mRNA levels; inhibited prdx1 mRNA level. The treatment of Tan IIa effectually ameliorated cellular oxidative stress. Exposure of MGO resulted in mitochondrial fission and decrease of opa1 and mfn1. No significant difference in mRNA levels of mfn2 and drp1 was detected between MGO and medium. Tan IIa reduced mitochondrial fragmentation, enhanced the mRNA levels of mfn1 and opa1 in MGO cultured BRECs. The short time exposure of cellular antioxidatants, dimethylthiourea (10 mM) and tiron (10 mM) had no effect on mitochondrial fission although they ameliorated cellular reactive oxygen species level. Moreover, overexpression of glyoxalase 1 (GLO1) increased key proteins of mitochondrial fusion, including opa1 and mfn1 in BRECs cultured with MGO. However, inhibition of GLO1 by siRNA abolished the effect of Tan IIa on induction of mitochondrial fusion in MGO cultured BRECs. In conclusion, MGO caused the injury of retinal endothelial cells through induction of mitochondrial dysfunction and mitochondrial fission, the treatment of Tan IIa ameliorated mitochondrial dysfunction and fission induced by AGEs through enhancing GLO1.

The effects of bioactive components from the rhizome of Salvia miltiorrhiza (Danshen) on the characteristics of Alzheimer's disease

Alzheimer's disease (AD) is a common human neurodegenerative disease, which is characterized by the progressive loss of memory and the cognitive impairment. Since the etiology of AD is still unknown, it is extremely difficult to develop the effective drugs for preventing or slowing the AD process. The major characteristics of AD such as amyloid β plaques, neurofibrillary tangles, mitochondrial dysfunction, and autophagy dysfunction are commonly used as the important indicators for evaluating the effects of potential candidate drugs. The rhizome of Salvia miltiorrhiza (known as 'Danshen' in Chinese), a famous traditional Chinese medicine, which is widely used for the treatment of hyperlipidemia, stroke, cardiovascular and cerebrovascular diseases. Increasing evidences suggest that the bioactive components of Danshen can improve cognitive deficits in mice, protect neuronal cells, reduce tau hyperphosylation, prevent amyloid-β fiber formation and disaggregation. Here we briefly summarize the studies regarding the effects of bioactive component from Danshen on those major characteristics of AD in preclinical studies, as well as explore the potential of these Danshen component in the treatment of AD.

Tanshinone IIA Ameliorates Spatial Learning and Memory Deficits by Inhibiting the Activity of ERK and GSK-3β

BACKGROUND

Alzheimer disease (AD) is the most common type of dementia which is becoming a primary problem in the present society, but it lacks effective treatment methods and means of AD. Tanshinone IIA (Tan IIA) has been reported to have neuroprotective effects to restrain the Aβ_25-35-mediated apoptosis. However, few studies try to understand how Aβ_1-42 affects hyperphosphorylation of tau and how Tan IIA regulates this process at the molecular level.

METHODS

Fifty male Sprague-Dawley rats were randomly divided into 5 groups and infused through the lateral ventricle with Aβ_1-42 except the control group. Then the rats were treated with Tan IIA through intragastric administration for 4 weeks. After the ability of learning and memory being measured, histomorphological examination and Western blot were used to detect the possible mechanism in the AD-associated model rats.

RESULTS

We observed that Aβ_1-42 infusion could induce spatial learning and memory deficits in rats. Simultaneously, Aβ_1-42 also could reduce the neuron in cornu ammonis 1 and dentate gyrus of hippocampus, as well as increase the levels of cleaved caspase 3, hyperphosphorylated tau at the sites Ser396, Ser404, and Thr205 with enhancing staining of black granules in brain. We also found that Aβ_1-42 could increase the activity of extracellular signal-regulated protein kinase (ERK) and glycogen synthase kinase-3β (GSK-3β). Meanwhile, these phenomena could be ameliorated when Tan IIA was used.

CONCLUSION

We concluded that Tan IIA might have neuroprotective effect and improving learning and memory ability to be a viable candidate in AD therapy with mechanisms involving the ERK and GSK-3β signal pathway.

The attenuation of HIV-1 Tat-induced neurotoxicity by Salvianic acid A and Danshen granule

The neurotoxicity of HIV-1 Tat protein contributes significantly to the pathogenesis of HAND, and hence the attractive therapeutic strategies focusing on Tat-induced neurotoxicity are warranted. Salvia miltiorrhiza have been known to antioxidant property and neuroprotective effects. The Danshen granule is the pharmaceutical dosage forms of Salvia miltiorrhiza and Salvianic acid A is an essential chemical constituent of Salvia miltiorrhiza. However, the protective effects of Salvianic acid A and Danshen granule on Tat-induced neurotoxicity remain unknown. Here, we found that Salvianic acid A and Danshen granule remarkable inhibited Tat-induced cell death, blocked LDH release and rescued dendritic spine loss. Furthermore, Salvianic acid A and Danshen granule significantly ameliorates Tat-induced intracellular ROS and MDA production, attenuates cell apoptosis. In addition, Salvianic acid A and Danshen granule pretreatment obviously increases antioxidant enzymatic activity of CAT, SOD and GSH-Px and inhibits apoptotic pathways. In conclusion, this study demonstrated that Salvianic acid A and Danshen granule provides substantial neuroprotection against Tat-induced neurotoxicity, which may be new therapeutic agent in Tat induced HAND or neurodegenerative diseases.

Neuroanesthesiology Update

We provide a synopsis of innovative research, recurring themes, and novel experimental findings pertinent to the care of neurosurgical patients and critically ill patients with neurological diseases. We cover the following broad topics: general neurosurgery, spine surgery, stroke, traumatic brain injury, monitoring, and anesthetic neurotoxicity.

High-Dose Tanshinone IIA Suppresses Migration and Proliferation While Promoting Apoptosis of Astrocytoma Cells Via Notch-1 Pathway

Malignant astrocytoma is the most common malignant tumor with strong invasion in the central nervous system. Tanshinone IIA is an effective compound to suppress cell proliferation and promote cell apoptosis. However, there is little research about the role of tanshinone IIA in the treatment of astrocytoma. This study aimed to investigate the effect of tanshinone IIA on migration, proliferation and apoptosis of astrocytoma cells. The efficacy of tanshinone IIA on migration, proliferation and apoptosis of astrocytoma cells were evaluated by flow cytometry and the assays of plate clone formation, CCK-8, wound healing and transwell migration. The protein molecule and signaling pathway were detected by western blot. High-dose tanshinone IIA suppressed migration and proliferation of astrocytoma cells while promoting apoptosis of astrocytoma cells. The western blot results showed that there were high Notch-1 protein expression and low c-Myc, MMP-9 and Bcl-2 activation in the high-dose tanshinone IIA group compared with the control group. High-dose tanshinone IIA suppresses astrocytoma cell proliferation, migration while promoting apoptosis through Notch-1 pathway. Tanshinone IIA may be used to develop new drugs for the treatment of astrocytoma.

HP-β-cyclodextrin as an inhibitor of amyloid-β aggregation and toxicity

Amyloid deposits of misfolded amyloid-β protein (Aβ) on neuronal cells are a pathological hallmark of Alzheimer's disease (AD). Prevention of the abnormal Aβ aggregation has been considered as a promising therapeutic strategy for AD treatment. To prevent reinventing the wheel, we proposed to search the existing drug database for other diseases to identify potential Aβ inhibitors. Herein, we reported the inhibitory activity of HP-β-cyclodextrin (HP-β-CD), a well-known sugar used in drug delivery, genetic vector, environmental protection and treatment of Niemann-Pick disease type C1 (NPC1), against Aβ1-42 aggregation and Aβ-induced toxicity, with the aim of adding a new function as a sugar-based Aβ inhibitor. Experimental data showed that HP-β-CD molecules were not only nontoxic to cells, but also greatly inhibited Aβ fibrillization and reduced Aβ-induced toxicity in a concentration-dependent manner. At an optimal molar ratio of Aβ : HP-β-CD = 1 : 2, HP-β-CD enabled the reduction of 60% of Aβ fibrils and increased the cell viability to 92%. Such concentration-dependent inhibitor capacity of HP-β-CD was likely attributed to several combined effects, including the enhancement of Aβ-HP-β-CD interactions, prevention of structural transition of Aβ peptides towards β-sheet structures, and reduction of self-aggregation of HP-β-CD. In parallel, molecular simulations further revealed the atomic details of HP-β-CD interacting with the Aβ oligomer, showing that HP-β-CD had a high tendency to interact with hydrophobic residues of Aβ in two β-strands and the N-terminal tail. More importantly, we identified that the inner hydrophobic cavity of HP-β-CD was a key active site for Aβ inhibition. Once the inner cavity of HP-β-CD was blocked by a small hydrophobic molecule of ferulic acid, HP-β-CD completely lost its inhibition capacity against Aβ. Given the already established pharmaceutical functions of HP-β-CD in drug delivery, our findings suggest that HP-β-CD has great potential to be designed as a sugar-based Aβ inhibitor.

Tanshinone IIA Attenuates Sevoflurane Neurotoxicity in Neonatal Mice

BACKGROUND

Sevoflurane is the most widely used inhalational anesthetic in pediatric medicine. Despite this, sevoflurane has been reported to exert potentially neurotoxic effects on the developing brain. Clinical interventions and treatments for these effects are limited. Tanshinone IIA (Tan IIA), extracted from Salvia miltiorrhiza (Danshen), has been documented to alleviate cognitive decline in traditional applications. Therefore, we hypothesized that preadministration of Tan IIA may attenuate sevoflurane-induced neurotoxicity, suggesting that Tan IIA is a new and promising drug capable of counteracting the effects of cognitive dysfunction produced by general anesthetics.

METHODS

To test this hypothesis, neonatal C57 mice (P6) were exposed to 3% sevoflurane for 2 hours with or without Tan IIA pretreatment at a dose of 10 mg/kg or 20 mg/kg for 3 consecutive days. Cognitive behavior tests such as open field tests and fear conditioning were performed to evaluate locomotor and cognitive function at P31 and P32. At P8, other separate tests, including TdT mediated dUTP Nick End Labeling (TUNEL) assay, immunohistochemistry, Western blotting, enzyme-linked immunosorbent assay, and electron microscopy, were performed. The mean differences among groups were compared using 1-way analysis of variance followed by Bonferroni post hoc multiple comparison tests.

RESULTS

Repeated exposure to sevoflurane leads to significant cognitive impairment in mice, which may be explained by increased apoptosis, overexpression of neuroinflammatory markers, and changes in synaptic ultrastructure. Interestingly, preadministration of Tan IIA ameliorated these neurocognitive deficits, as shown by increased freezing percentages on the fear conditioning test (sevoflurane+Tan IIA [20 mg/kg] versus sevoflurane, mean difference, 19, 99% confidence interval for difference, 6.4-31, P < .0001, n = 6). The treatment also reduced the percentage of TUNEL-positive nuclei (sevoflurane versus sevoflurane+Tan IIA [20 mg/kg], 2.6, 0.73-4.5, P = .0004, n = 6) and the normalized expression of cleaved caspase-3 (sevoflurane versus sevoflurane+Tan IIA [20 mg/kg], 0.27, 0.02-0.51, P = .0046, n = 5). Moreover, it attenuated the production of the neuroinflammatory mediators interleukin (IL)-1β and IL-6 (normalized sevoflurane versus sevoflurane+Tan IIA [20 mg/kg]: IL-1β: 0.75, 0.47-1.0; P < .0001; IL-6: 0.66, 0.35-0.97; P < .0001; n = 10 per group). Finally, based on measurements of postsynaptic density, the treatment preserved synaptic ultrastructure (sevoflurane+Tan IIA [20 mg/kg] versus sevoflurane, 42, 20-66; P < .0001; n = 12 per group).

CONCLUSIONS

These results indicate that Tan IIA can alleviate sevoflurane-induced neurobehavioral abnormalities and may decrease neuroapoptosis and neuroinflammation.

Di-Huang-Yi-Zhi herbal formula attenuates amyloid-β-induced neurotoxicity in PC12 cells

Traditional Chinese medicine can be used for Alzheimer's disease management, such as the modern herbal formula Di-Huang-Yi-Zhi (DHYZ). In the present study, neuronal differentiated PC12 cells were used as a model to evaluate the effects of DHYZ against amyloid-β peptide 25-35 (Aβ_25-35) induced neurotoxicity, particularly regarding cell proliferation, apoptosis and related events. Following treatment with DHYZ, cell viability, cell membrane damage, apoptosis, mitochondrial membrane potential, cytochrome c release, caspase-3 activity and levels of reactive oxygen species in PC12 cells were detected. The results demonstrated that pretreatment with DHYZ significantly protected PC12 cells from Aβ_25-35-induced proliferation inhibition, lactate dehydrogenase release and apoptosis, as well as upregulating mitochondrial membrane potential and downregulating cytochrome c release and caspase-3 activation. DHYZ also inhibited the Aβ_25-35-induced reactive oxygen species generation in PC12 cells. These observations suggest that DHYZ protected PC12 cells from the Aβ-induced neurotoxicity.

Neuroprotective effect of combining tanshinone IIA with low-dose methylprednisolone following acute spinal cord injury in rats

The present study compared the potential neuroprotective effect of tanshinone IIA (TIIA) monotherapy, methylprednisolone (MP) monotherapy and combined treatment in an adult acute spinal cord injury (ASCI) rat model. The current study used the weight-drop method (Allen's Impactor) in the rat model and the mechanical scratch method in primary spinal cord neuron culture to determine whether the combined treatment was able to reduce the required dosage of MP in the treatment of ASCI to produce a similar or improved therapeutic effect. In vivo male Sprague Dawley rats (n=60) were randomly divided into 5 groups, of which 12 rats were selected for the sham group and T9-T11 laminectomies, leading to ASCI, were performed on 48 of the 60 rats using a 10 g ×25 mm weight-drop at the level of T10 spinal cord. Therefore, the ASCI group (n=12) included the 'laminectomy and weight-drop'. The remaining 36 ASCI model animals were subdivided into 3 groups (n=12 each group): TIIA group (30 mg/kg/day), MP group (30 mg/kg) and combined treatment group (TIIA 30 mg/kg/day + MP 20 mg/kg). Neuronal function following ASCI was evaluated using the Basso Beattie Bresnahan (BBB) locomotor rating scale. Levels of the anti-apoptotic factor B-cell lymphoma-2 (Bcl-2), the pro-apoptotic factors Bcl-2 associated protein X (Bax) and caspase-3, and the inflammatory associated factor nuclear factor-κB, were analyzed by western blot analysis. Immunohistochemistry was used to detect caspase-3. To investigate the underlying mechanism, the anti-oxidative effect of combination TIIA and MP treatment was assessed by measuring the activity of malondialdehyde (MDA) and superoxide dismutase (SOD) in ASCI. In agreement with the experiment in vivo, primary neurons were prepared from the spinal cord of one-day-old Sprague-Dawley rats' and co-cultured with astrocytes from the brain cortex. The injury of neurons was induced by mechanical scratch and levels of apoptosis factors were analyzed by western blot analysis. The results of the current study indicated that injured animals in the combined treatment group exhibited a significant increase in BBB scores (P<0.05). TIIA + MP combined treatment and MP treatment was observed to reduce the expression of pro-apoptotic factors and promote neuron survival in vivo and in vitro. Combined treatment may promote neuroprotection through reduced apoptosis and inflammation caused by ASCI, similar to MP alone. Combined treatment reversed the decrease of SOD and the increase of MDA level caused by ASCI. In addition, combined treatment decreased the expression of caspase-3 in the neurons following ASCI in rats, as indicated by immunofluorescence double labeling. Overall, the present study indicates that the combined treatment of TIIA and MP may protect the neurons by stimulating the rapid initiation of neuroprotection following ASCI and reduce the dosage of MP in the treatment of ASCI required to produce the same or improved neuroprotective effects in vivo and in vitro.

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.

Tanshinone IIA attenuates Aβ25–35-induced spatial memory impairment via upregulating receptors for activated C kinase1 and inhibiting autophagy in hippocampus

Objectives

Tanshinone IIA (Tan IIA) may exert significant protective effects against the neurotoxicity induced by β-amyloid protein (Aβ). This study was designed to investigate the possible neuroprotective mechanism of Tan IIA on Aβ25–35-induced spatial memory impairment in mice.

Methods

After 3 weeks of preventive treatment (Tan IIA or oil), all male Kunming mice were subjected to Aβ25–35 (10 μl, intracerebroventricularly (i.c.v.)) to establish the spatial memory impairment model. The Morris water maze (MWM), haematoxylin and eosin staining, real-time PCR and Western blot were performed to determine the ability of spatial memory, neuronal damage and expression of extracellular signal-regulated kinase (ERK), receptors for activated C kinase1 (RACK1) and autophagy-related genes. Additionally, ShRACK1 was used to decrease the level of RACK1 in the hippocampus to test Beclin1 in hippocampus by real-time PCR and Western blot.

Key findings

Tanshinone IIA (Tan IIA, 80 mg/kg) administration notably protected mice from Aβ25-35-induced spatial memory impairment and neurotoxicity, increased pERK/ERK and the expression of RACK1, and reduced the elevated levels of BECLIN1 and LC3-II/I in the hippocampus. In addition, ShRACK1 i.c.v markedly upregulated BECLIN1 level, but not altered Beclin1 mRNA expression in the hippocampus.

Conclusions

Tanshinone IIA may exert neuroprotective effects via upregulating RACK1 and inhibiting autophagy in the hippocampus of mice.

Pharmacological Effects of Active Components of Chinese Herbal Medicine in the Treatment of Alzheimer's Disease: A Review

Alzheimer's disease (AD), the most common neurodegenerative disorder associated with dementia, not only severely decreases the quality of life for its victims, but also brings a heavy economic burden to the family and society. Unfortunately, few chemical drugs designed for clinical applications have reached the expected preventive or therapeutic effect so far, and combined with their significant side-effects, there is therefore an urgent need for new strategies to be developed for AD treatment. Traditional Chinese Medicine has accumulated many experiences in the treatment of dementia during thousands of years of practice; modern pharmacological studies have confirmed the therapeutic effects of many active components derived from Chinese herbal medicines (CHM). Ginsenoside Rg1, extracted from Radix Ginseng, exerts a [Formula: see text]-secretase inhibitor effect so as to decrease A[Formula: see text] aggregation. It can also inhibit the apoptosis of neuron cells. Tanshinone IIA, extracted from Radix Salviae miltiorrhizae, and baicalin, extracted from Radix Scutellariae[Formula: see text] can inhibit the oxidative stress injury in neuronal cells. Icariin, extracted from Epimedium brevicornum, can decrease A[Formula: see text] levels and the hyperphosphorylation of tau protein, and can also inhibit oxidative stress and apoptosis. Huperzine A, extracted from Huperzia serrata, exerts a cholinesterase inhibitor effect. Evodiamine, extracted from Fructus Evodiae, and curcumin, extracted from Rhizoma Curcumae Longae, exert anti-inflammatory actions. Curcumin can act on A[Formula: see text] and tau too. Due to the advantages of multi-target effects and fewer side effects, Chinese medicine is more appropriate for long-term use. In this present review, the pharmacological effects of commonly used active components derived from Chinese herbal medicines in the treatment of AD are discussed.

Oxidative Stress and Salvia miltiorrhiza in Aging-Associated Cardiovascular Diseases

Aging-associated cardiovascular diseases (CVDs) have some risk factors that are closely related to oxidative stress. Salvia miltiorrhiza (SM) has been used commonly to treat CVDs for hundreds of years in the Chinese community. We aimed to explore the effects of SM on oxidative stress in aging-associated CVDs. Through literature searches using Medicine, PubMed, EMBASE, Cochrane library, CINAHL, and Scopus databases, we found that SM not only possesses antioxidant, antiapoptotic, and anti-inflammatory effects but also exerts angiogenic and cardioprotective activities. SM may reduce the production of reactive oxygen species by inhibiting oxidases, reducing the production of superoxide, inhibiting the oxidative modification of low-density lipoproteins, and ameliorating mitochondrial oxidative stress. SM also increases the activities of catalase, manganese superoxide dismutase, glutathione peroxidase, and coupled endothelial nitric oxide synthase. In addition, SM reduces the impact of ischemia/reperfusion injury, prevents cardiac fibrosis after myocardial infarction, preserves cardiac function in coronary disease, maintains the integrity of the blood-brain barrier, and promotes self-renewal and proliferation of neural stem/progenitor cells in stroke. However, future clinical well-designed and randomized control trials will be necessary to confirm the efficacy of SM in aging-associated CVDs.

Neuroprotective effect of Decalepis hamiltonii on cyclophosphamide-induced oxidative stress in the mouse brain

BACKGROUND

Cyclophosphamide (CP), one of the most widely used antineoplastic drugs, causes toxic side effects on vital organs including brain. In this study, we have investigated neuroprotective potential of the aqueous extract of the roots of Decalepis hamiltonii (DHA) against CP-induced oxidative stress in the mouse brain.

METHODS

Swiss albino male mice were pre-treated with DHA (50 and 100 mg/kg b.w.) for 10 consecutive days followed by an injection with CP intraperitoneally (25 mg/kg b.w.) for 10 days 1 h after DHA treatment; 16 h later, they were euthanized, their brains were immediately removed, and biochemical and molecular analyses were conducted.

RESULTS

The results indicated that injection of CP induced oxidative stress in the mouse brain as evident from the increased lipid peroxidation, reactive oxygen species, depletion of glutathione and reduced activities of the antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase. Treatment with DHA significantly mitigated the CP-induced oxidative stress. Moreover, expression of genes for the antioxidant enzymes was downregulated by CP treatment which was reversed by DHA.

CONCLUSIONS

In conclusion, DHA protected the brain from oxidative stress induced by CP, and therefore, it could be a promising nutraceutical as a supplement in cancer chemotherapy in order to ameliorate the toxic side effects of cancer drugs.