Tanshinone IIA Inhibits Glutamate-Induced Oxidative Toxicity through Prevention of Mitochondrial Dysfunction and Suppression of MAPK Activation in SH-SY5Y Human Neuroblastoma Cells

Role of Glutamate Excitotoxicity in Glioblastoma Growth and Its Implications in Treatment

Glioblastoma is a highly malignant and invasive type of primary brain tumor that originates from astrocytes. Glutamate, a neurotransmitter in the brain plays a crucial role in excitotoxic cell death. Excessive glutamate triggers a pathological process known as glutamate excitotoxicity, leading to neuronal damage. This excitotoxicity contributes to neuronal death and tumor necrosis in glioblastoma, resulting in seizures and symptoms such as difficulty in concentrating, low energy, depression, and insomnia. Glioblastoma cells, derived from astrocytes, fail to maintain glutamate-glutamine homeostasis, releasing excess glutamate into the extracellular space. This glutamate activates ionotropic N-methyl-D-aspartate (NMDA) receptors and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors on nearby neurons, causing hyperexcitability and triggering apoptosis through caspase activation. Additionally, glioblastoma cells possess calcium-permeable AMPA receptors, which are activated by glutamate in an autocrine manner. This activation increases intracellular calcium levels, triggering various signaling pathways. Alkylating agent temozolomide has been used to counteract glutamate excitotoxicity, but its efficacy in directly combating excitotoxicity is limited due to the development of resistance in glioblastoma cells. There is an unmet need for alternative biochemical agents that can have the greatest impact on reducing glutamate excitotoxicity in glioblastoma. In this review, we discuss the mechanism and various signaling pathways involved in glutamate excitotoxicity in glioblastoma cells. We also examine the roles of various receptor and transporter proteins, in glutamate excitotoxicity and highlight biochemical agents that can mitigate glutamate excitotoxicity in glioblastoma and serve as potential therapeutic agents.

Tanshinone T1/T2A inhibits non-small cell lung cancer through Lin28B-let-7-BORA/MYC regulatory network

BACKGROUND

Lung cancer is the leading cause of cancer-related deaths worldwide. Tanshinones are a group of compounds in Salvia miltiorrhiza. Although the effects of tanshinone I (T1) and tanshinone IIA (T2A) are widely concerned, the mechanisms of T1 and T2A in lung cancer is rarely studied.

EXPERIMENTAL PROCEDURE

Xenograft tumor growth was performed to detect the role of T1/T2A in vivo. Next-generation sequencing of miRNA expression profiles in T1/T2A-treated A549 cells showed that T1/T2A upregulated the expression of the let-7 family. Then, let-7a-5p and its downstream target gene BORA were identified as the research objects in this paper. Mechanistically, we examined the interplay between miR-let-7 and BORA through the dual-luciferase reporter assay. Finally, the potential regulatory role of T1/T2A on Lin28B and MYC was explored.

RESULTS

This study found that the let-7 family was significantly up-regulated via "Next-generation" sequencing (NGS) in the T1/T2A-treated A549 cell line, while BORA was downregulated. BORA was confirmed as a direct target of let-7. LncRNA MYCLo-5 was up-regulated after treatment with tanshinones. Knockdown of MYCLo-5 promoted the cell cycle and proliferation of non-small cell lung cancer (NSCLC) cells.

CONCLUSIONS

This study explored the effects of tanshinone T1 and T2A on NSCLC in vitro and in vivo, revealing the T1/T2A-let-7/BORA/MYCLo-5 regulatory pathway, which provided new insights for lung cancer treatment.

Oligoprotective Activity of Levetiracetam against Glutamate Toxicity: An In vitro Study

INTRODUCTION

The role of glutamate in the development of some brain pathological conditions, such as multiple sclerosis, has been well described. Levetiracetam (LEV), a new broad-spectrum antiseizure medicine, is widely used to control certain types of seizures. Apart from its anti-seizure activity, LEV exerts neuroprotection via anti-inflammatory, antioxidant, and antiapoptotic effects. The current study was designed to evaluate the protective potential of LEV against glutamate-induced injury in OLN-93 oligodendrocytes.

METHODS

At first, the potential negative impact of LEV on OLN-93 viability was evaluated. After that, the cells were concurrently treated with LEV (0-100 μM) and glutamate (8 mM) for 24 h. The viability, redox status, and the rate of apoptosis of OLN-93 cells were then assessed using 3-[4,5-dimethylthiazol- 2-yl]-2,5-diphenyl-2H-tetrazolium bromide (MTT), 2',7' dichlorodihydrofluorescein diacetate (H2DCFDA), 2-thiobarbituric acid reactive substances (TBARS) and annexin V/propidium iodide (PI) assays, respectively. Moreover, caspase-3 expression, as a marker of cell apoptosis, was evaluated by Western blotting.

RESULTS

LEV at 1-800 μM did not have any negative effect on cell survival. Treatment with LEV (50 and 100 μM) substantially enhanced the cell viability following glutamate insult. The cytoprotective activity of LEV (50 and 100 μM) against glutamate toxicity was accompanied by reduced reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) level. Moreover, 100 μM of LEV inhibited apoptosis and decreased the expression level of cleaved caspase-3 following glutamate exposure.

CONCLUSION

Taken together, the results suggested that LEV has protective effects against glutamate-mediated cytotoxicity in OLN-93 cells. The oligoprotective action of LEV was shown to be exerted via inhibition of oxidative stress and cellular apoptosis.

In silico identification and verification of Tanshinone IIA-related prognostic genes in hepatocellular carcinoma

BACKGROUND

Currently, adequate treatment and prognostic prediction means for Hepatocellular Carcinoma (HCC) haven't entered into medical vision. Tanshinone IIA (TanIIA) is a natural product, which can be utilized as a potential treatment of HCC due to its high anti-tumor activity. However, the effect on HCC prognosis, as well as the potential targets and molecular mechanism of TanIIA still remain ambiguous. Herein, we investigated them via network pharmacology, explored TanIIA-related prognostic genes by machine learning methods, and verified using molecular docking and cell experiments.

METHODS

Potential TanIIA-targeted genes and HCC-related genes were obtained from the corresponding database. The Protein-Protein Interaction (PPI) network and enrichment analyses of the intersection targets were conducted. Furthermore, a TanIIA-related prognostic model was built and verified. We attempted to explore the expression of the TanIIA-related prognostic genes and evaluate its chemotherapeutic sensitivities and the immune infiltrations. Followed by exploration of anti-tumor activity on the human HCC cells Hep3B and HepG2 cell lines in vitro (CCK-8, flow cytometry and transwell assay), the docking molecular was performed. Ultimately, the corresponding protein expressions were determined by western blotting.

RESULTS

A total of 64 intersecting targets were collected. Similarly, GO/KEGG enrichment analysis showed that TanIIA can inhibit HCC by affecting multiple pathways, especially the MAPK signaling pathway. A five-gene signature related to TanIIA was constructed on account of Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression model. Among five genes, ALB, ESR1 and SRC tend to be core genes because of probable status as potential targets for sorafenib. Molecular docking results demonstrated the potential for active interaction between the core genes relevant proteins and TanIIA. Studies in vitro had shown that TanIIA regulated the expressions of Bcl-2, Bax and MMP9 in HCC cells, inhibiting their growth, inducing apoptosis and preventing cell invasion. Additionally, we are able to detect an up-regulated trend in the expression of ALB and ESR1, while a down-regulated in the expression of SRC by TanIIA.

CONCLUSION

Regulating the expression of TanIIA-related gene signatures (ALB, SRC and ESR1), and inhibiting the SRC/MAPK/ERK signaling axis might potentially contribute to the TanIIA treatment of HCC. And the three gene signatures could be identified for predicting the prognosis of HCC, which may provide novel biomarkers for HCC treatment.

Sodium Tanshinone IIA Sulfonate alleviates vascular senescence in diabetic mice by modulating the A20-NFκB-NLRP3 inflammasome-catalase pathway

Diabetes accelerates vascular senescence, which is the basis for atherosclerosis and stiffness. The activation of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and oxidative stress are closely associated with the deteriorative senescence in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs). For decades, Sodium Tanshinone IIA Sulfonate (STS) has been utilized as a cardiovascular medicine with acknowledged anti-inflammatory and anti-oxidative properties. Nevertheless, the impact of STS on vascular senescence remains unexplored in diabetes. Diabetic mice, primary ECs and VSMCs were transfected with the NLRP3 overexpression/knockout plasmid, the tumor necrosis factor alpha-induced protein 3 (TNFAIP3/A20) overexpression/knockout plasmid, and treated with STS to detect senescence-associated markers. In diabetic mice, STS treatment maintained catalase (CAT) level and vascular relaxation, reduced hydrogen peroxide probe (ROSgreen) fluorescence, p21 immunofluorescence, Senescence β-Galactosidase Staining (SA-β-gal) staining area, and collagen deposition in aortas. Mechanistically, STS inhibited NLRP3 phosphorylation (serine 194), NLRP3 dimer formation, NLRP3 expression, and NLRP3-PYCARD (ASC) colocalization. It also suppressed the phosphorylation of IkappaB alpha (IκBα) and NFκB, preserved A20 and CAT levels, reduced ROSgreen density, and decreased the expression of p21 and SA-β-gal staining in ECs and VSMCs under HG culture. Our findings indicate that STS mitigates vascular senescence by modulating the A20-NFκB-NLRP3 inflammasome-CAT pathway in hyperglycemia conditions, offering novel insights into NLRP3 inflammasome activation and ECs and VSMCs senescence under HG culture. This study highlights the potential mechanism of STS in alleviating senescence in diabetic blood vessels, and provides essential evidence for its future clinical application.

Biocompatible aggregation-induced emission active polyphosphate-manganese nanosheets with glutamine synthetase-like activity in excitotoxic nerve cells

Glutamine synthetase (GS) is vital in maintaining ammonia and glutamate (Glu) homeostasis in living organisms. However, the natural enzyme relies on adenosine triphosphate (ATP) to activate Glu, resulting in impaired GS function during ATP-deficient neurotoxic events. To date, no reports demonstrate using artificial nanostructures to mimic GS function. In this study, we synthesize aggregation-induced emission active polyP-Mn nanosheets (STPE-PMNSs) based on end-labeled polyphosphate (polyP), exhibiting remarkable GS-like activity independent of ATP presence. Further investigation reveals polyP in STPE-PMNSs serves as phosphate source to activate Glu at low ATP levels. This self-feeding mechanism offers a significant advantage in regulating Glu homeostasis at reduced ATP levels in nerve cells during excitotoxic conditions. STPE-PMNSs can effectively promote the conversion of Glu to glutamine (Gln) in excitatory neurotoxic human neuroblastoma cells (SH-SY5Y) and alleviate Glu-induced neurotoxicity. Additionally, the fluorescence signal of nanosheets enables precise monitoring of the subcellular distribution of STPE-PMNSs. More importantly, the intracellular fluorescence signal is enhanced in a conversion-responsive manner, allowing real-time tracking of reaction progression. This study presents a self-sustaining strategy to address GS functional impairment caused by ATP deficiency in nerve cells during neurotoxic events. Furthermore, it offers a fresh perspective on the potential biological applications of polyP-based nanostructures.

Role of CD36 in central nervous system diseases

CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases. CD36 was recently found to be widely expressed in various cell types in the nervous system, including endothelial cells, pericytes, astrocytes, and microglia. CD36 mediates a number of regulatory processes, such as endothelial dysfunction, oxidative stress, mitochondrial dysfunction, and inflammatory responses, which are involved in many central nervous system diseases, such as stroke, Alzheimer's disease, Parkinson's disease, and spinal cord injury. CD36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand, thereby achieving inhibition of CD36-mediated pathways or functions. Here, we reviewed the mechanisms of action of CD36 antagonists, such as Salvianolic acid B, tanshinone IIA, curcumin, sulfosuccinimidyl oleate, antioxidants, and small-molecule compounds. Moreover, we predicted the structures of binding sites between CD36 and antagonists. These sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.

The neuroprotective potential of phytochemicals in traumatic brain injury: mechanistic insights and pharmacological implications

Traumatic brain injury (TBI) leads to brain damage, comprising both immediate primary damage and a subsequent cascade of secondary injury mechanisms. The primary injury results in localized brain damage, while the secondary damage initiates inflammatory responses, followed by the disruption of the blood-brain barrier, infiltration of peripheral blood cells, brain edema, and the release of various immune mediators, including chemotactic factors and interleukins. TBI disrupts molecular signaling, cell structures, and functions. In addition to physical tissue damage, such as axonal injuries, contusions, and haemorrhages, TBI interferes with brain functioning, impacting cognition, decision-making, memory, attention, and speech capabilities. Despite a deep understanding of the pathophysiology of TBI, an intensive effort to evaluate the underlying mechanisms with effective therapeutic interventions is imperative to manage the repercussions of TBI. Studies have commenced to explore the potential of employing natural compounds as therapeutic interventions for TBI. These compounds are characterized by their low toxicity and limited interactions with conventional drugs. Moreover, many natural compounds demonstrate the capacity to target various aspects of the secondary injury process. While our understanding of the pathophysiology of TBI, there is an urgent need for effective therapeutic interventions to mitigate its consequences. Here, we aimed to summarize the mechanism of action and the role of phytochemicals against TBI progression. This review discusses the therapeutic implications of various phytonutrients and addresses primary and secondary consequences of TBI. In addition, we highlighted the roles of emerging phytochemicals as promising candidates for therapeutic intervention of TBI. The review highlights the neuroprotective roles of phytochemicals against TBI and the mechanistic approach. Furthermore, our efforts focused on the underlying mechanisms, providing a better understanding of the therapeutic potential of phytochemicals in TBI therapeutics.

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.

Sodium tanshinone IIA sulfonate ameliorates neointima by protecting endothelial progenitor cells in diabetic mice

BACKGROUND

Endothelial progenitor cells (EPCs) transplantation is one of the effective therapies for neointima associated with endothelial injury. Diabetes impairs the function of EPCs and cumbers neointima prevention of EPC transplantation with an ambiguous mechanism. Sodium Tanshinone IIA Sulfonate (STS) is an endothelium-protective drug but whether STS protects EPCs in diabetes is still unknown.

METHODS

EPCs were treated with High Glucose (HG), STS, and Nucleotide-binding Domain-(NOD) like Receptor 3 (NLRP3), caspase-1, the Receptor of Advanced Glycation End products (AGEs) (RAGE) inhibitors, Thioredoxin-Interacting Protein (TXNIP) siRNA, and EPC proliferation, differentiation functions, and senescence were detected. The treated EPCs were transplanted into db/db mice with the wire-injured Common Carotid Artery (CCA), and the CD31 expression and neointima were detected in the CCA inner wall.

RESULTS

We found that STS inhibited HG-induced expression of NLRP3, the production of active caspase-1 (p20) and mature IL-1β, the expression of catalase (CAT) cleavage, γ-H2AX, and p21 in EPCs. STS restored the expression of Ki67, CD31 and von Willebrand Factor (vWF) in EPCs; AGEs were found in the HG-treated EPCs supernatant, and RAGE blocking inhibited the expression of TXNIP and the production of p20, which was mimicked by STS. STS recovered the expression of CD31 in the wire-injured CCA inner wall and the prevention of neointima in diabetic mice with EPCs transplantation.

CONCLUSION

STS inhibits the aggravated neointima hyperplasia by protecting the proliferation and differentiation functions of EPC and inhibiting EPC senescence in diabetic mice. The mechanism is related to the preservation of CAT activity by inhibiting the RAGE-TXNIP-NLRP3 inflammasome pathway.

Therapeutic prospects of naturally occurring p38 MAPK inhibitors tanshinone IIA and pinocembrin for the treatment of SARS-CoV-2-induced CNS complications

P38 mitogen-activated protein kinase (p38 MAPK) signaling pathway is closely related to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) replication and hyperinflammatory responses in coronavirus disease 2019 (COVID-19). Therefore, blood-brain barrier-penetrating p38 MAPK inhibitors have good potential for the treatment of central nervous system (CNS) complications of COVID-19. The aim of the present study is the characterization of the therapeutic potential of tanshinone IIA and pinocembrin for the treatment of CNS complications of COVID-19. Studies published in high-quality journals indexed in databases Scopus, Web of Science, PubMed, and so forth were used to review the therapeutic capabilities of selected compounds. In continuation of our previous efforts to identify agents with favorable activity/toxicity profiles for the treatment of COVID-19, tanshinone IIA and pinocembrin were identified with a high ability to penetrate the CNS. Considering the nature of the study, no specific time frame was determined for the selection of studies, but the focus was strongly on studies published after the emergence of COVID-19. By describing the association of COVID-19-induced CNS disorders with p38 MAPK pathway disruption, this study concludes that tanshinone IIA and pinocembrin have great potential for better treatment of these complications. The inclusion of these compounds in the drug regimen of COVID-19 patients requires confirmation of their effectiveness through the conduction of high-quality clinical trials.

The therapeutic effect of tanshinone IIA in mouse astrocytes after treatment with Angiostrongylus cantonensis fifth-stage larval excretory-secretory products

BACKGROUND

Angiostrongylus cantonensis is an important food-borne zoonotic parasite that causes eosinophilic meningitis and meningoencephalitis in humans. Excretory-secretory products (ESPs) are valuable targets for studying host-parasite relationships. ESPs are composed of a variety of molecules that are used to penetrate defensive barriers and avoid immune attack of the host. Tanshinone IIA (TSIIA) is a vasoactive cardioprotective drug that is widely used in studies evaluating potential therapeutic mechanisms. In this study, we will evaluate the therapeutic effects of TSIIA in mouse astrocytes after A. cantonensis fifth-stage larvae (L5) ESPs treatment.

METHODS

Here, we examined the therapeutic effect of TSIIA by real-time qPCR, western blotting, activity assay, and cell viability assays.

RESULTS

First, the results showed that TSIIA can elevate cell viability in astrocytes after stimulation with ESPs. On the other hand, TSIIA downregulated the expression of apoptosis-related molecules. However, the expression of molecules related to antioxidant, autophagy, and endoplasmic reticulum stress was significantly increased. The results of antioxidant activation assays showed that the activities of superoxide dismutase (SOD), glutathione S-transferase (GST), and catalase were significantly increased. Finally, we found that cell apoptosis and oxidative stress were reduced in TSIIA-treated astrocytes by immunofluorescence staining.

CONCLUSION

The findings from this study suggest that TSIIA can reduce cellular damage caused by A. cantonensis L5 ESPs in astrocytes and clarify the related molecular mechanisms.

Acai Berry (Euterpe sp.) Extracts Are Neuroprotective against L-Glutamate-Induced Toxicity by Limiting Mitochondrial Dysfunction and Cellular Redox Stress

Aberrant accumulation of the neurotransmitter L-glutamate (L-Glu) has been implicated as a mechanism of neurodegeneration, and the release of L-Glu after stroke onset leads to a toxicity cascade that results in neuronal death. The acai berry (Euterpe oleracea) is a potential dietary nutraceutical. The aim of this research was to investigate the neuroprotective effects of acai berry aqueous and ethanolic extracts to reduce the neurotoxicity to neuronal cells triggered by L-Glu application. L-Glu and acai berry effects on cell viability were quantified using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, and effects on cellular bioenergetics were assessed via quantitation of the levels of cellular ATP, mitochondrial membrane potential (MMP), and production of reactive oxygen species (ROS) in neuroblastoma cells. Cell viability was also evaluated in human cortical neuronal progenitor cell culture after L-Glu or/and acai berry application. In isolated cells, activated currents using patch-clamping were employed to determine whether L-Glu neurotoxicity was mediated by ionotropic L-Glu-receptors (iGluRs). L-Glu caused a significant reduction in cell viability, ATP, and MMP levels and increased ROS production. The co-application of both acai berry extracts with L-Glu provided neuroprotection against L-Glu with sustained cell viability, decreased LDH production, restored ATP and MMP levels, and reduced ROS levels. Whole-cell patch-clamp recordings showed that L-Glu toxicity is not mediated by the activation of iGluRs in neuroblastoma cells. Fractionation and analysis of acai berry extracts with liquid chromatography-mass spectrometry identified several phytochemical antioxidants that may have provided neuroprotective effects. In summary, the acai berry contains nutraceuticals with antioxidant activity that may be a beneficial dietary component to limit pathological deficits triggered by excessive L-Glu accumulations.

Neuroprotective Strategies for Stroke by Natural Products: Advances and Perspectives

Cerebral ischemic stroke is a disease with high prevalence and incidence. Its management focuses on rapid reperfusion with intravenous thrombolysis and endovascular thrombectomy. Both therapeutic strategies reduce disability, but the therapy time window is short, and the risk of bleeding is high. Natural products (NPs) have played a key role in drug discovery, especially for cancer and infectious diseases. However, they have made little progress in clinical translation and pose challenges to the treatment of stroke. Recently, with the investigation of precise mechanisms in cerebral ischemic stroke and the technological development of NP-based drug discovery, NPs are addressing these challenges and opening up new opportunities in cerebral stroke. Thus, in this review, we first summarize the structure and function of diverse NPs, including flavonoids, phenols, terpenes, lactones, quinones, alkaloids, and glycosides. Then we propose the comprehensive neuroprotective mechanism of NPs in cerebral ischemic stroke, which involves complex cascade processes of oxidative stress, mitochondrial damage, apoptosis or ferroptosis-related cell death, inflammatory response, and disruption of the blood-brain barrier (BBB). Overall, we stress the neuroprotective effect of NPs and their mechanism on cerebral ischemic stroke for a better understanding of the advances and perspective in NPs application that may provide a rationale for the development of innovative therapeutic regimens in ischemic stroke.

Traditional Chinese medicine in treating ischemic stroke by modulating mitochondria: A comprehensive overview of experimental studies

Ischemic stroke has been a prominent focus of scientific investigation owing to its high prevalence, complex pathogenesis, and difficulties in treatment. Mitochondria play an important role in cellular energy homeostasis and are involved in neuronal death following ischemic stroke. Hence, maintaining mitochondrial function is critical for neuronal survival and neurological improvement in ischemic stroke, and mitochondria are key therapeutic targets in cerebral stroke research. With the benefits of high efficacy, low cost, and high safety, traditional Chinese medicine (TCM) has great advantages in preventing and treating ischemic stroke. Accumulating studies have explored the effect of TCM in preventing and treating ischemic stroke from the perspective of regulating mitochondrial structure and function. In this review, we discuss the molecular mechanisms by which mitochondria are involved in ischemic stroke. Furthermore, we summarized the current advances in TCM in preventing and treating ischemic stroke by modulating mitochondria. We aimed to provide a new perspective and enlightenment for TCM in the prevention and treatment of ischemic stroke by modulating mitochondria.

DHPA Protects SH-SY5Y Cells from Oxidative Stress-Induced Apoptosis via Mitochondria Apoptosis and the Keap1/Nrf2/HO-1 Signaling Pathway

Oxidative stress in the brain is highly related to the pathogenesis of Alzheimer’s disease (AD). It could be induced by the overproduction of reactive oxygen species (ROS), produced by the amyloid beta (Aβ) peptide and excess copper (Cu) in senile plaques and cellular species, such as ascorbic acid (AA) and O₂. In this study, the protective effect of 5-hydroxy-7-(4′-hydroxy-3′-methoxyphenyl)-1-phenyl-3-heptanone (DHPA) on Aβ_(1–42)/Cu²⁺/AA mixture-treated SH-SY5Y cells was investigated via in vitro and in silico studies. The results showed that DHPA could inhibit Aβ/Cu²⁺/AA-induced SH-SY5Y apoptosis, OH· production, intracellular ROS accumulation, and malondialdehyde (MDA) production. Further research demonstrated that DHPA could decrease the ratio of Bax/Bcl-2 and repress the increase of mitochondrial membrane potential (MMP) of SH-SY5Y cells, to further suppress the activation of caspase-3, and inhibit cell apoptosis. Meanwhile, DHPA could inhibit the Aβ/Cu²⁺/AA-induced phosphorylation of Erk1/2 and P38 in SH-SY5Y cells, and increase the expression of P-AKT. Furthermore, DHPA could bind to Keap1 to promote the separation of Nrf2 to Keap1 and activate the Keap1/Nrf2/HO-1 signaling pathway to increase the expression of heme oxygenase-1 (HO-1), quinone oxidoreductase-1 (NQO1), glutathione (GSH), and superoxide dismutase (SOD). Thus, our results demonstrated that DHPA could inhibit Aβ/Cu²⁺/AA-induced SH-SY5Y apoptosis via scavenging OH·, inhibit mitochondria apoptosis, and activate the Keap1/Nrf2/HO-1 signaling pathway.

Is L-Glutamate Toxic to Neurons and Thereby Contributes to Neuronal Loss and Neurodegeneration? A Systematic Review

L-glutamate (L-Glu) is a nonessential amino acid, but an extensively utilised excitatory neurotransmitter with critical roles in normal brain function. Aberrant accumulation of L-Glu has been linked to neurotoxicity and neurodegeneration. To investigate this further, we systematically reviewed the literature to evaluate the effects of L-Glu on neuronal viability linked to the pathogenesis and/or progression of neurodegenerative diseases (NDDs). A search in PubMed, Medline, Embase, and Web of Science Core Collection was conducted to retrieve studies that investigated an association between L-Glu and pathology for five NDDs: Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD). Together, 4060 studies were identified, of which 71 met eligibility criteria. Despite several inadequacies, including small sample size, employment of supraphysiological concentrations, and a range of administration routes, it was concluded that exposure to L-Glu in vitro or in vivo has multiple pathogenic mechanisms that influence neuronal viability. These mechanisms include oxidative stress, reduced antioxidant defence, neuroinflammation, altered neurotransmitter levels, protein accumulations, excitotoxicity, mitochondrial dysfunction, intracellular calcium level changes, and effects on neuronal histology, cognitive function, and animal behaviour. This implies that clinical and epidemiological studies are required to assess the potential neuronal harm arising from excessive intake of exogenous L-Glu.

Salvia miltiorrhiza Protects Endothelial Dysfunction against Mitochondrial Oxidative Stress

Salvia miltiorrhiza (SM) is a common traditional Chinese medicine used in the treatment of cardiovascular and cerebrovascular diseases. Endothelial dysfunction plays an important role in the pathology of cardiovascular diseases. Endothelial dysfunction may induce inflammation and change vascular tone and permeability. The main pathological mechanism of endothelial dysfunction is the formation of reactive oxygen species (ROS). Mitochondria are the main source of energy and can also produce large amounts of ROS. Recent studies have shown that extracts of SM have antioxidative, anti-inflammatory, and antithrombus properties. In this review, we discuss the mechanism of oxidative stress in the mitochondria, endothelial dysfunction, and the role of SM in these oxidative events.

Recent Research Progress (2015-2021) and Perspectives on the Pharmacological Effects and Mechanisms of Tanshinone IIA

Tanshinone IIA (Tan IIA) is an important characteristic component and active ingredient in Salvia miltiorrhiza, and its various aspects of research are constantly being updated to explore its potential application. In this paper, we review the recent progress on pharmacological activities and the therapeutic mechanisms of Tan IIA according to literature during the years 2015-2021. Tan IIA shows multiple pharmacological effects, including anticarcinogenic, cardiovascular, nervous, respiratory, urinary, digestive, and motor systems activities. Tan IIA modulates multi-targets referring to Nrf2, AMPK, GSK-3β, EGFR, CD36, HO-1, NOX4, Beclin-1, TLR4, TNF-α, STAT3, Caspase-3, and bcl-2 proteins and multi-pathways including NF-κB, SIRT1/PGC1α, MAPK, SREBP-2/Pcsk9, Wnt, PI3K/Akt/mTOR pathways, TGF-β/Smad and Hippo/YAP pathways, etc., which directly or indirectly influence disease course. Further, with the reported targets, the potential effects and possible mechanisms of Tan IIA against diseases were predicted by bioinformatic analysis. This paper provides new insights into the therapeutic effects and mechanisms of Tan IIA against diseases.

Sodium Tanshinone IIA Sulfonate Attenuates Cigarette Smoke Extract-Induced Mitochondrial Dysfunction, Oxidative Stress, and Apoptosis in Alveolar Epithelial Cells by Enhancing SIRT1 Pathway

Emphysema is one of the most important phenotypes for chronic obstructive pulmonary disease (COPD). Apoptosis in alveolar epithelial cells (AECs) causes the emphysematous alterations in the smokers and patients with COPD. Sirtuin 1 (SIRT1) is able to attenuate mitochondrial dysfunction, oxidative stress, and to modulate apoptosis. It has been shown that sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA, protects against cigarette smoke (CS)-induced emphysema/COPD in mice. However, the mechanisms underlying these findings remain unclear. Here, we investigate whether and how STS attenuates AEC apoptosis via a SIRT1-dependent mechanism. We found that STS treatment decreased CS extract (CSE)-induced apoptosis in human alveolar epithelial A549 cells. STS reduced oxidative stress, improved mitochondrial function and mitochondrial membrane potential (ΔΨm), and restored mitochondrial dynamics-related protein expression. Moreover, STS promoted mitophagy, and increased oxidative phosphorylation protein levels (complexes I-IV) in CSE-stimulated A549 cells. The protective effects of STS were associated with SIRT1 upregulation, because SIRT1 inhibition by EX 527 significantly attenuated or abolished the ability of STS to reverse the CSE-induced mitochondrial damage, oxidative stress, and apoptosis in A549 cells. In conclusion, STS ameliorates CSE-induced AEC apoptosis by improving mitochondrial function and reducing oxidative stress via enhancing SIRT1 pathway. These findings provide novel mechanisms underlying the protection of STS against CS-induced COPD.

The implications of mitochondria in doxorubicin treatment of cancer in the context of traditional and modern medicine

Doxorubicin (DOX) is an antibiotic anthracycline extensively used in the treatment of different malignancies, such as breast cancer, lymphomas and leukemias. The cardiotoxicity induced by DOX is one of the most important pathophysiological events that limit its clinical application. Accumulating evidence highlights mitochondria as a central role in this process. Modulation of mitochondrial functions as therapeutic strategy for DOX-induced cardiotoxicity has thus attracted much attention. In particular, emerging studies investigated the potential of natural mitochondria-targeting compounds from Traditional Chinese Medicine (TCM) as adjunct or alternative treatment for DOX-induced toxicity. This review summarizes studies about the mechanisms of DOX-induced cardiotoxicity, evidencing the importance of mitochondria and presenting TCM treatment alternatives for DOX-induced cardiomyopathy.

Anti-Inflammatory Dipeptide, a Metabolite from Ambioba Secretion, Protects Cerebral Ischemia Injury by Blocking Apoptosis Via p-JNK/Bax Pathway

MQ (l-methionyl-l-glutamic acid), anti-inflammatory dipeptide, is one of the metabolites of monocyte locomotion inhibitory factor, a thermostable pentapeptide secreted by Entamoeba histolytica. Monocyte locomotion inhibitory factor injection has been approved as an investigational drug for the potential neural protection in acute ischemic stroke. This study further investigated the neuroprotective effect of MQ in ischemic brain damage. Ischemia-reperfusion injury of the brain was induced in the rat model by middle cerebral artery occlusion. 2,3,5-triphenyltetrazolium chloride staining assay was used to measure cerebral infarction areas in rats. Laser Doppler measurement instrument was used to detect blood flow changes in the rat model. Nissl staining and NeuN staining were utilized to observe the numbers and structures of neuron cells, and the pathological changes in the brain tissues were examined by hematoxylin–eosin staining. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) staining was used to assess cell apoptosis. The changes in oxidative stress indexes, superoxide dismutase and malondialdehyde (MDA), were measured in serum. Methyl thiazolyl tetrazolium was used to measure the survival rates of PC12 cells. Flow cytometry assessed the apoptosis rates and the levels of reactive oxygen species. Real-time PCR was used to evaluate the mRNA expression levels, and Western blotting was used to analyze the changes in protein levels of p-JNK, Bax, cleaved Caspase3. We revealed that MQ improved neurobehavior, decreased cerebral infarction areas, altered blood flow volume, and the morphology of the cortex and hippocampus. On the other hand, it decreased the apoptosis of cortical neurons and the levels of MDA, and increased the levels of superoxide dismutase. In vitro studies demonstrated that MQ enhanced the cell survival rates and decreased the levels of reactive oxygen species. Compared to the oxygen-glucose deprivation/reperfusion group, the protein and mRNA expressions of p-JNK, Bax, cleaved Caspase3 was decreased significantly. These findings suggested that MQ exerts a neuroprotective effect in cerebral ischemia by blocking apoptosis via the p-JNK/Bax pathway.

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 targeting mitochondria: emerging therapeutics for age-associated neurological disorders

Mitochondria are the primary source of energy production in the brain thereby supporting most of its activity. However, mitochondria become inefficient and dysfunctional with age and to a greater extent in neurological disorders. Thus, mitochondria represent an emerging drug target for many age-associated neurological disorders. This review summarizes recent advances (covering from 2010 to May 2020) in the use of natural products from plant, animal, and microbial sources as potential neuroprotective agents to restore mitochondrial function. Natural products from diverse classes of chemical structures are discussed and organized according to their mechanism of action on mitochondria in terms of modulation of biogenesis, dynamics, bioenergetics, calcium homeostasis, and membrane potential, as well as inhibition of the oxytosis/ferroptosis pathway. This analysis emphasizes the significant value of natural products for mitochondrial pharmacology as well as the opportunities and challenges for the discovery and development of future neurotherapeutics.

Icariin reduces Glu-induced excitatory neurotoxicity via antioxidative and antiapoptotic pathways in SH-SY5Y cells

Excessive glutamate (Glu) can lead to significant effects on neural cells through the generation of neurotoxic or excitotoxic cascades. Icariin (ICA) is a main active ingredient of Chinese Medicine Berberidaceae epimedium L., and has many biological activities, such as antiinflammation, antioxidative stress, and anti-depression. This study aims to evaluate the effect of ICA on Glu-induced excitatory neurotoxicity of SH-SY5Y cells. The cell viability assay was evaluated by the CCK-8 assay. The apoptosis, reactive oxygen species (ROS), and mitochondrial membrane potential were assessed by flow cytometry. Intracellular Ca²⁺ concentration was determined by using the fluorescent probe Fluo-3. Protein expression was detected by western blotting analysis. ICA can significantly enhance the SH-SY5Y cell viability reduced by Glu. At the same time, ICA can significantly reduce apoptosis, ROS, nitric oxide (NO) levels, and intracellular Ca²⁺ concentration, and significantly inhibit the increase of mitochondrial membrane potential. In addition, ICA significantly increased the expression of P47phox and iNOS, decreased p-JNK/JNK, p-P38/P38, Bax/Bcl-2, active caspase-3, and active caspase-9. These results indicate that ICA may reduce the excitatory neurotoxicity of Glu-induced SH-SY5Y cells through suppression of oxidative stress and apoptotic pathways, suggesting that ICA could be a potential therapeutic candidate for neurological disorders propagated by Glu toxicity.

Osthole-Loaded Nanoemulsion Enhances Brain Target in the Treatment of Alzheimer's Disease via Intranasal Administration

Osthole (OST) is a natural coumarin compound that exerts multiple pharmacologic effects. However, the poor water solubility and the low oral absorption of OST limit its clinical application for the treatment of neurologic diseases. A suitable preparation needs to be tailored to evade these unfavourable properties of OST. In this study, an OST nanoemulsion (OST-NE) was fabricated according to the pseudoternary phase diagram method, which was generally used to optimize the prescription in light of the solubility of OST in surfactants and cosurfactants. The final composition of OST-NE was 3.6% of ethyl oleate as oil phase, 11.4% of the surfactant (polyethylene glycol ester of 15-hydroxystearic acid: polyoxyethylene 35 castor oil = 1 : 1), 3% of polyethylene glycol 400 as cosurfactant, and 82% of the aqueous phase. The pharmacokinetic study of OST-NE showed that the brain-targeting coefficient of OST was larger by the nasal route than that by the intravenous route. Moreover, OST-NE inhibited cell death, decreased the apoptosis-related proteins (Bax and caspase-3), and enhanced the activity of antioxidant enzymes (superoxide dismutase and glutathione) in L-glutamate-induced SH-SY5Y cells. OST-NE improved the spatial memory ability, increased the acetylcholine content in the cerebral cortex, and decreased the activity of acetylcholinesterase in the hippocampus of Alzheimer's disease model mice. In conclusion, this study indicates that the bioavailability of OST was improved by using the OST-NE via the nasal route. A low dose of OST-NE maintained the neuroprotective effects of OST, such as inhibiting apoptosis and oxidative stress and regulating the cholinergic system. Therefore, OST-NE can be used as a possible alternative to improve its bioavailability in the prevention and treatment of Alzheimer's disease.

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.

Potential protective roles of phytochemicals on glutamate-induced neurotoxicity: A review

Glutamate, as an essential neurotransmitter, has been thought to have different roles in the central nervous system (CNS), including nerve regeneration, synaptogenesis, and neurogenesis. Excessive glutamate causes an up-regulation of the multiple signaling pathways, including phosphoinositide-3 kinase/protein kinase B (PI3K/Akt), Akt/mammalian target of rapamycin (mTOR) protein, mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK)1/2, and autophagy that are involved in neurodegenerative diseases pathophysiology. There are numerous findings on curcumin, astaxanthin, thymoquinone, and berberine, as natural products, which have outstanding effects in cell signaling far beyond their anti-oxidant activity, considering as a potential therapeutic target for glutamate excitotoxicity. Herein, we address the role of glutamate as a potential target in neurodegenerative diseases and discuss the protective effects of certain phytochemicals on glutamate-induced neurotoxicity.

Guanosine enhances glutamate uptake and oxidation, preventing oxidative stress in mouse hippocampal slices submitted to high glutamate levels

Glutamate (Glu) is the main mammalian brain neurotransmitter. Concerning the glutamatergic neurotransmission, excessive levels of glutamate in the synaptic cleft are extremally harmful. This phenomenon, named as excitotoxicity is involved in various acute and chronic brain diseases. Guanosine (GUO), an endogenous guanine nucleoside, possesses neuroprotective effects in several experimental models of glutamatergic excitotoxicity, an effect accompanied by an increase in astrocytic glutamate uptake. Therefore, the objective of this study was to investigate the involvement of an additional putative parameter, glutamate oxidation to CO₂, involved in ex-vivo GUO neuroprotective effects in mouse hippocampal slices submitted to glutamatergic excitotoxicity. Mice were sacrificed by decapitation, the hippocampi were removed and sliced. The slices were incubated for various times and concentrations of Glu and GUO. First, the concentration of Glu that produced an increase in L-[¹⁴C(U)]-Glu oxidation to CO₂ without cell injury was determined at different time points (between 0 and 90 min); 1000 μM Glu increased Glu oxidation between 30 and 60 min of incubation without cell injury. Under these conditions (Glu concentration and incubation time), 100 μM GUO increased Glu oxidation (35%). Additionally, 100 μM GUO increased L-[3,4-3H]-glutamate uptake (45%) in slices incubated with 1000 μM Glu (0-30 min). Furthermore, 1000  μM Glu increased reactive species levels, SOD activity, and decreased GPx activity, and GSH content after 30 and 60 min; 100 μM GUO prevented these effects. This is the first study demonstrating that GUO simultaneously promoted an increase in the uptake and utilization of Glu in excitotoxicity-like conditions preventing redox imbalance.

Tanshinone IIA pretreatment promotes cell survival in human lung epithelial cells under hypoxia via AP-1-Nrf2 transcription factor

Activator protein-1 (AP-1) plays a decisive role in cell proliferation, apoptosis, and inflammation under hypoxia; thus, AP-1 subunits or dimers could be modulated for a desired phenomenon in a cell using a suitable compound of therapeutic potential. Herein, we used Tanshinone-IIA as an AP-1 (subunits) modulator, and the purpose of the study was to investigate the signaling mechanism exhibited by Tan-IIA in facilitating tolerance to hypoxia. A549 cells were pretreated with Tan-IIA and exposed to hypoxia for 6, 12, 24, and 48 h. Biochemical and molecular parameters were assessed in order to trace the signaling pathway. Tan-IIA attenuated hypoxia-induced oxidative stress by modulating the expression of AP-1 subunits (via. MAPK) and Nrf2 transcription factor, which in turn were responsible for maintaining the higher levels of antioxidant enzymes and genes (HO). Tan-IIA increased the cell survival. This could be attributed to an increased NO level via iNOS gene and activated JNK, ERK pathway that induced c-jun/c-fos, c-jun/fosB, junD/c-fos, and junD/fosB heterodimers. This in turn leads to the cell cycle progression by activating cyclins (D and B). This was further confirmed by the lower levels of p53 and their downstream genes (p16, p21, p27). In addition, Tan-IIA decreased pro-inflammatory cytokine levels by inhibiting the formation of junB/fra-1 heterodimer regulated by p38. Tan-IIA increased cell survival to hypoxia by maintaining the higher levels of cellular iNOS, HO-1, jun-D, c-jun, fos B via Nrf2-AP-1.

Natural products as safeguards against monosodium glutamate-induced toxicity

Monosodium glutamate is a sodium salt of a nonessential amino acid, L-glutamic acid, which is widely used in food industry. Glutamate plays an important role in principal brain functions including formation and stabilization of synapses, memory, cognition, learning, as well as cellular metabolism. However, ingestion of foodstuffs rich in monosodium glutamate can result in the outbreak of several health disorders such as neurotoxicity, hepatotoxicity, obesity and diabetes. The usage of medicinal plants and their natural products as a therapy against MSG used in food industry has been suggested to be protective. Calendula officinalis, Curcuma longa, Green Tea, Ginkgo biloba and vitamins are some of the main natural products with protective effect against mentioned monosodium glutamate toxicity through different mechanisms. This review provides a summary on the toxicity of monosodium glutamate and the protective effects of natural products against monosodium glutamate -induced toxicity.

Tanshinone IIA prevents platelet activation and down-regulates CD36 and MKK4/JNK2 signaling pathway

BACKGROUND

Tanshinone IIA (TS IIA), a multi-pharmaceutical compound from traditional Chinese herb, is effective for treatment of atherothrombosis. However, the underlying mechanisms of TS IIA-mediated anti-platelet activation effect are still poorly understood. As shown in our previous study, platelet-derived microvesicles (PMVs) generated in response to oxidant insult could activate CD36/mitogen-activated protein kinase kinase 4/Jun N-terminal kinase 2 (CD36/MKK4/JNK2) signals and lead to platelet activation. The present study aims to investigate the effect of TS IIA on platelet activation and the possible mechanisms.

METHODS

The production of PMVs induced by Interleukin 6 (IL-6) was detected by flow cytometry. We performed activating studies of platelets with PMVs derived from IL-6-treated platelets (IL-6-PMVs) in vitro. Sometimes, platelet suspensions were incubated with serial concentrations of TS IIA for 15 min before being stimulated with IL-6-PMVs. Expression of platelet integrin α_IIbβ₃ and CD36 was detected by flow cytometry. Phosphorylation of MKK4 and JNK were detected by immunoblotting.

RESULTS

Here we demonstrated firstly that TS IIA could prevent platelet activation induced by PMVs and down-regulates CD36 and MKK4/JNK2 signaling pathway. CD36 may be the target of atherosclerosis (AS)-related thrombosis.

CONCLUSIONS

This study showed the possible mechanisms of TS IIA-mediated anti-platelet activation and may provide a new strategy for the treatment of AS-related thrombosis by targeting platelet CD36.

Tanshinone IIA protects lens epithelial cells from H2 O 2 -induced injury by upregulation of lncRNA ANRIL

Tanshinone IIA is a lipophilic diterpene extracted from the Salvia miltiorrhiza bunge, possessing antiapoptotic and antioxidant activities. The purpose of this study was to explore the effects of Tanshinone IIA on age-related nuclear cataract. Human lens epithelial cell line SRA01/04 was subjected to H ₂ O ₂ to mimic a cell model of cataract. Cell Counting Kit-8 assay, flow cytometer, and reactive oxygen species (ROS) detection were performed to evaluate the effect of Tanshinone IIA pretreatment on SRA01/04 cells injured by H ₂ O ₂ . Besides, the real-time quantitative polymerase chain reaction was used to assess the expression of long noncoding RNA (lncRNA) antisense noncoding RNA in the INK4 locus (ANRIL). Western blot analysis was performed to detect the expression of core proteins involved in cell survival and nuclear factor-κB (NF-κB) pathway. H ₂ O ₂ significantly decreased SRA01/04 cells viability, whereas increased apoptosis and ROS generation. This phenomenon was coupled with the upregulated p53, p21, Bax, cleaved caspase-3, and the downregulated cyclinD1, CDK4, and Bcl-2. Tanshinone IIA pretreatment protected SRA01/04 cells against H ₂ O ₂ -induced injury. In the meantime, the expression of lncRNA ANRIL was upregulated by Tanshinone IIA. And, the protective effects of Tanshinone IIA on H ₂ O ₂ -stimulated SRA01/04 cells were abolished when lncRNA ANRIL was silenced. Moreover, the elevated expression of lncRNA ANRIL induced by Tanshinone IIA was abolished by BAY 11-7082 (an inhibitor of NF-κB). To conclude, Tanshinone IIA protects SRA01/04 cells from apoptosis triggered by H ₂ O ₂ . Tanshinone IIA confers its protective effects possibly via modulation of NF-κB signaling and thereby elevating the expression of lncRNA ANRIL.

Rapid Identification of Tanshinone IIA Metabolites in an Amyloid-β1-42 Induced Alzherimer's Disease Rat Model using UHPLC-Q-Exactive Qrbitrap Mass Spectrometry

Alzheimer’s disease (AD) is a neurodegenerative disorder that damages health and welfare of the elderly, and there has been no effective therapy for AD until now. It has been proved that tanshinone IIA (tan IIA) could alleviate pathological symptoms of AD via improving non-amyloidogenic cleavage of amyloid precursor protein, decreasing the accumulations of p-tau and amyloid-β_1–42 (Aβ_1–42), and so forth. However, the further biochemical mechanisms of tan IIA are not clear. The experiment was undertaken to explore metabolites of tan IIA in AD rats induced by microinjecting Aβ_1-42 in the CA1 region of hippocampus. AD rats were orally administrated with tan IIA at 100 mg/kg weight, and plasma, urine, faeces, kidney, liver and brain were then collected for metabolites analysis by UHPLC-Q-Exactive Qrbitrap mass spectrometry. Consequently, a total of 37 metabolites were positively or putatively identified on the basis of mass fragmentation behavior, accurate mass measurements and retention times. As a result, methylation, hydroxylation, dehydration, decarbonylation, reduction reaction, glucuronidation, glycine linking and their composite reactions were characterized to illuminate metabolic pathways of tan IIA in vivo. Several metabolites presented differences in the distribution of tan IIA between the sham control and the AD model group. Overall, these results provided valuable references for research on metabolites of tan IIA in vivo and its probable active structure for exerting neuroprotection.

Astragalus polysaccharides suppresses high glucose-induced metabolic memory in retinal pigment epithelial cells through inhibiting mitochondrial dysfunction-induced apoptosis by regulating miR-195

BACKGROUND

Metabolic memory contributes to the development of diabetic retinopathy (DR), which is the complication of diabetes. But it's still unknown how to prevent the metabolic memory to treat the DR. In our study, we want to examine the function of Astragalus polysaccharides (APS) in the metabolic memory of retinal pigment epithelium (RPE) pretreated with high glucose (HG).

METHODS

ARPE-19 and PRPE cells were exposed to HG followed by normal glucose (NG) treatment with or without APS. QPCR was used to examine the levels of miR-195 and Bcl-2. MDA and SOD detection assays were used to examine the oxidative stress level. Western blotting and immunostaining were applied to detect the protein level of mitochondrial damage and apoptotic signaling pathway. Flow cytometry and TUNEL staining were used to analyze cell apoptosis. Luciferase assay was used to examine the direct target of miR-195.

RESULTS

APS treatment significantly decreased the expression of miR-195, while increased the expression of Bcl-2 with optimized dosages which were induced by HG treatment, even after replacing the HG with NG. And we found Bcl-2 was the direct target of miR-195. APS alleviated the oxidative stress, mitochondrial damage and cell apoptosis induced by HG and HG + NG treatments in RPE cells via regulating miR-195. Furthermore, we found overexpression of miR-195 abolished the alleviated effects of APS on the HG-treated RPE cells.

CONCLUSIONS

APS suppressed high glucose-induced metabolic memory in retinal pigment epithelial cells through inhibiting mitochondrial dysfunction-induced apoptosis by regulating miR-195.

Neuroprotective effects of Bergenia ciliata on NMDA induced injury in SH-SY5Y cells and attenuation of cognitive deficits in scopolamine induced amnesia in rats

Bergenia ciliata (Haw) Sternb. possess immunomodulatory, anti-inflammatory, antioxidant, anti-urolithiatic, wound healing, anti-malarial, anti-diabetic and anti-cancer properties. Moreover, the methanolic extracts of the rhizomes of the plant were found to demonstrate beneficial neuroprotective effects in the intracerebroventricular streptozotocin-induced model in rats. Thus, the present study was undertaken to further explore the neuroprotective potential of the aqueous (BA) and methanolic extracts (BM) of B. ciliata through various in-vitro and in-vivo studies. Both the extracts at all tested concentrations i.e. 50-50,000 ng/mL did not cause any significant reduction of cell viability of SH-SY5Y cells when tested for 48 h when assessed through MTT and resazurin metabolism- based cell viability assays. The pre-treatment with the extracts could confer significant (p < 0.001) and dose-dependent protective effects against NMDA induced injury in SH-SY5Y cells. BM [IC₅₀: 5.7 and 5.19 μg/mL for acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) respectively] led to more potent inhibition of both the enzymes as compared to BA (IC₅₀: 227.12 and 23.25 μg/mL for AChE and BuChE respectively). BM also proved to be a 1.85-fold better scavenger of the DPPH free radicals as compared to BA. Thus, BM was taken further for the evaluation of the beneficial effects of 14-day pre-treatment in rats in the scopolamine (2 mg/kg, i.p.) induced amnesia model at 125, 250 and 500 mg/kg, p.o. BM pre-treatment at 250 and 500 mg/kg could significantly ameliorate the cognitive impairment (p < 0.001), inhibit AChE (p < 0.001) and BuChE (p < 0.05) activity, restore GSH levels (p < 0.05) in serum and brain homogenates and recover the morphology of hippocampal neurons back to normal. Moreover, the BM administration at 500 mg/kg also showed beneficial effects through the significant (p < 0.05) reduction of Aβ_1-42, phosphorylated tau (p-tau) and GSK-3β immunoreactivity in the brain homogenates of the intracerebroventricularly streptozotocin (ICV STZ) injected rats as observed from the results of the ELISA assays. The outcomes of the study unveiled that BM exerts its beneficial effects through prevention of NMDA induced excitotoxic cell death, dual cholinesterase inhibition, antioxidant activity coupled with the reduction of the immunoreactivity for the Aβ_1-42, p-tau and GSK-3β indicating its potential to be screened further for various other models to determine the exact mechanism of action.

Neuroprotective effects of bergenin in Alzheimer's disease: Investigation through molecular docking, in vitro and in vivo studies

Alzheimer's disease (AD) is an enervating and chronic progressive neurodegenerative disorder, occurring frequently in the elderly and adversely affecting intellectual capabilities and the cognitive processes. Bergenin possesses efficacious antioxidant, antiulcerogenic, anti-HIV, hepatoprotective, neuroprotective, anti-inflammatory and immunomodulatory activity along with antinociceptive effect and wound healing properties. Previous studies have shown that bergenin has in vitro bovine adrenal tyrosine hydroxylase inhibitory activity, mushroom tyrosinase inhibitory activities, β-secretase (BACE-1) enzyme inhibitory activity and prevented neuronal death in the primary culture of rat cortical neurons. Protein tyrosine phosphatase-1B (PTP1B) is an intriguing target for anticancer and antidiabetic drugs and has recently been implicated to act as a positive regulator of neuroinflammation. Bergenin is also found to inhibit human protein tyrosine phosphatase-1B (hPTP1B) in vitro. Thus, bergenin was screened by molecular docking study using GOLD suite (version 5.2), CCDC for predicting its activity against targets of AD management like acetylcholinesterase (AChE) (1B41), butyrylcholinesterase (BuChE) (1P0I), Tau protein kinase 1 (GSK-3β) (1J1B), BACE-1 (1FKN) wherein the GOLD score and fitness of bergenin were comparable to those of standard drugs like donepezil, galanthamine, physostigmine, etc. Bergenin demonstrated dose-dependent inhibition of both AChE and BuChE in vitro and found to be safe up to 50 μM when screened in vitro on SH-SY5Y cell lines by cytotoxicity studies using MTT and Alamar blue assays. It also led to dose-dependent prevention of NMDA induced toxicity in these cells. Pretreatment with bergenin (14 days) in rats at three dose levels (20, 40 and 80 mg/kg; p.o.) significantly (p < 0.01) and dose-dependently alleviated amnesia induced by scopolamine (2 mg/kg, i.p.). The therapeutic effect of bergenin supplementation for 28 days, at three dose levels, was also evaluated in streptozotocin (3 mg/kg, ICV, unilateral) induced AD model in Wistar rats using Morris water maze and Y maze on 7th, 14th, 21st and 28th days. STZ caused significant (p < 0.001) cognitive impairment and cholinergic deficit and increased oxidative stress in rats. Bergenin could significantly ameliorate STZ induced behavioral deficits, inhibit the AChE and BuChE activity in parallel with an increase in the diminished GSH levels in a dose-dependent fashion. The histopathological investigations were also supportive of this datum. The bergenin treatment at 80 mg/kg led to significant (p < 0.05) abatement of the raised Aβ-_1-42 levels and alleviated the perturbed p- tau levels leading to significantly low (p < 0.01) levels of p-tau in brain homogenates of rats as compared to ICV STZ injected rats. In conclusion, the observed effects might be attributed to the cholinesterase inhibitory activity of bergenin coupled with its antioxidant effect, anti-inflammatory activity and reduction of Aβ-_1-42 and p-tau levels which could have collectively helped in the attenuation of cognitive deficits. The current findings of the study are indicative of the promising preventive and ameliorative potential of bergenin in the management of AD through multiple targets.

Tanshinone IIA improves hypoxic ischemic encephalopathy through TLR‑4‑mediated NF‑κB signal pathway

Hypoxic ischemic encephalopathy (HIE) is the most common brain injury following hypoxia and/or ischemia caused by various factors during the perinatal period, resulting in detrimental neurological deficits in the nervous system. Tanshinone IIA (Tan‑IIA) is a potential agent for the treatment of cardiovascular and cerebrovascular diseases. In this study, the efficacy of Tan‑IIA was investigated in a newborn mouse model of HIE. The dynamic mechanism of Tan‑IIA was also investigated in the central nervous system of neonate mice. Intravenous injection of Tan‑IIA (5 mg/kg) was administered and changes in oxidative stress, inflammation and apoptosis‑associated proteins in neurons. Histology and immunohistochemistry was used to determine infarct volume and the number of damaged neurons by Fluoro‑Jade C staining. The effects of Tan‑IIA on mice with HIE were evaluated by body weight, brain water content, neurobehavioral tests and blood‑brain barrier permeability. The results demonstrated that the apoptosis rate was decreased following Tan‑IIA administration. Expression levels of pro‑apoptotic proteins, caspase‑3 and caspase‑9 and P53 were downregulated. Expression of Bcl‑2 anti‑apoptotic proteins was upregulated by Tan‑IIA treatment in neuro. Results also found that Tan‑IIA treatment decreased production of inflammatory cytokines such as interleukin‑1, tumor necrosis factor‑α, C‑X‑C motif chemokine 10, and chemokine (C‑C motif) ligand 12. Oxidative stress was also reduced by Tan‑IIA in neurons, as determined by the expression levels of superoxide dismutase, glutathione and catalase, and the production of reactive oxygen species. The results demonstrated that Tan‑IIA treatment reduced the infarct volume and the number of damaged neurons. Furthermore, body weight, brain water content and blood‑brain barrier permeability were markedly improved by Tan‑IIA treatment of newborn mice following HIE. Furthermore, the results indicated that Tan‑IIA decreased Toll‑like receptor‑4 (TLR‑4) and nuclear factor‑κB (NF‑κB) expression in neurons. TLR‑4 treatment of neuronal cell in vitro addition stimulated NF‑κB activity, and further enhanced the production of inflammatory cytokines and oxidative stress levels in neurons. In conclusion, these results suggest that Tan‑IIA treatment is beneficial for improvement of HIE through TLR‑4‑mediated NF‑κB signaling.

β-amyloid cytotoxicity is prevented by natural achillolide A

Alzheimer's disease (AD) is the most prevalent cause of dementia in adults. Current available drugs for AD transiently alleviate some of the symptoms, but do not modify the disease mechanism or cure it. Therefore, new drugs are desperately needed. Key contributors to AD are amyloid beta (Aβ)- and reactive oxygen species (ROS)-induced cytotoxicities. Plant-derived substances have been shown to affect various potential targets in various diseases including AD. Therefore, phytochemicals which can protect neuronal cells against these insults might help in preventing and treating this disease. In the following research, we have isolated the sesquiterpene lactone achillolide A from the plant Achillea fragrantissima and, for the first time, characterized its effects on Aβ-treated neuroblastoma cells. Aβ is a peptide derived from the sequential cleavage of amyloid precursor protein, and is part of the pathogenesis of AD. Our current study aimed to determine whether achillolide A can interfere with Aβ-induced processes in Neuro2a cells, and protect them from its toxicity. Our results show that achillolide A decreased Aβ-induced death and enhanced the viability of Neuro2a cells. In addition, achillolide A reduced the accumulation of Aβ-induced ROS and inhibited the phosphorylation of stress-activated protein kinase/c-Jun N-terminal kinase and p44/42 mitogen-activated protein kinase in these cells. We therefore suggest that achillolide A may have therapeutic potential for the treatment of AD.

Anti-Adipogenic Effects on 3T3-L1 Cells and Zebrafish by Tanshinone IIA

Tanshinone IIA is a diterpene quinone isolated from the roots of Salviamiltiorrhiza bunge that has traditionally been used in China for the treatment of cardiovascular and cerebrovascular disorders. Although there is recent evidence showing that tanshinone IIA has an anti-obesity effect, its underlying mechanism of anti-obesity effect is poorly understood. Here, we investigated the effect of tanshinone IIA on lipid accumulation in 3T3-L1 preadipocytes and zebrafish. Notably, tanshinone IIA at 10 μM concentration greatly reduced lipid accumulation and triglyceride (TG) contents during 3T3-L1 preadipocyte differentiation, suggesting its anti-adipogenic effect. On mechanistic levels, tanshinone IIA reduced the expression levels of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), and perilipin A but also the phosphorylation levels of signal transducer and activator of transcription-3/5 (STAT-3/5) in differentiating 3T3-L1 cells. In addition, tanshinone IIA strongly inhibited leptin and resistin mRNA expression in differentiating 3T3-L1 cells. Importantly, the tanshinone IIA's lipid-reducing effect was also seen in zebrafish. In sum, these findings demonstrate that tanshinone IIA has anti-adipogenic effects on 3T3-L1 cells and zebrafish, and its anti-adipogenic effect on 3T3-L1 cells is largely attributable to the reduced expression and/or phosphorylation levels of C/EBP-α, PPAR-γ, FAS, perilipin A, and STAT-3/5.