Beta-asarone attenuates ischemia–reperfusion-induced autophagy in rat brains via modulating JNK, p-JNK, Bcl-2 and Beclin 1

Volatile oil of Acori tatarinowii rhizoma: potential candidate drugs for mitigating dementia

Objective

This study aims to elucidate the mitigating effects of the volatile oil of Acori tatarinowii rhizoma (ATR) on dementia, in order to provide a reference for future research and applications of the volatile oil of ATR in the field of dementia.

Materials and methods

A search strategy was developed using terms such as "Acori tatarinowii rhizoma," "Acorus tatarinowii Schott," "Asarone," and "Dementia." The literature search was conducted in PubMed, Web of Science, and Google Scholar, and studies not meeting the inclusion criteria were excluded. This study summarizes the main metabolites, active ingredients, toxicological properties, and pharmacokinetic characteristics of the volatile oil from ATR in mitigating dementia, with a particular focus on its potential mechanisms of action. Furthermore, the study highlights the limitations of existing research and offers insights into future research directions.

Results

The volatile oil of ATR mitigates dementia through multiple pathways, including reducing abnormal protein aggregation, promoting neurogenesis, inhibiting neuronal apoptosis, regulating neurotransmitters, improving synaptic function, modulating autophagy, countering cellular stress, reducing neuroinflammation, and alleviating vascular risk factors.

Conclusion

The multi-pathway pharmacological effects of the volatile oil of ATR are well-aligned with the complex mechanisms of dementia progression, highlighting its significant therapeutic potential for anti-dementia applications. This provides new perspectives for the development of more effective anti-dementia drugs. Nonetheless, further rigorous and high-quality preclinical and clinical investigations are required to address key issues, including the chemical characterization of the volatile oil of ATR, potential synergistic effects among active ingredients, toxicity profiles, and definitive clinical efficacy.

Online identification of chemical constituents in Mongolian medicine Zhachong-13 pills by UHPLC-Q-exactive Orbitrap MS

Zhachong-13 pills (ZC-13), as a traditional prescription of Mongolian medicine, are often used in the clinical practice of Mongolian hospitals for the treatment of stroke and rheumatic arthritis. In this experiment, UHPLC-Q-Exactive Orbitrap MS was used to explore the chemical composition of ZC-13. The results showed that 315 compounds were identified or inferred, including 56 alkaloids, 77 2-(2-phenylethyl)chromones, 61 flavonoids, 31 tannins, 8 coumarins, 16 lignans, 21 terpenoids, 5 amino acids, 19 organic acids, and 21 other components. In addition, the pharmacological activities related to anti-cerebral ischemia of these components were summarized. This result laid a foundation for further study on the pharmacodynamic material basis of ZC-13 and provided a scientific basis for the formulation of ZC-13 quality specifications.

Breviscapine ameliorates autophagy by activating the JAK2/STAT5/BCL2 pathway in a transient cerebral ischemia rat model

Breviscapine (Bre), an extract from Erigeron breviscapus, has been widely used to treat cerebral ischemia but the mechanisms of its neuroprotective effects need to be clarified. The present study investigated whether Bre could alleviate excessive autophagy induced by cerebral ischemia in the rat middle cerebral artery occlusion (MCAO) ischemia model via activating the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 5 (STAT5)/B-cell lymphoma 2 (BCL2) pathway. Rats were randomly divided into 5 groups, i.e. Sham group, MCAO+saline group, MCAO+Bre group, MCAO+DMSO (Dimethyl sulfoxide) group, and MCAO+Bre+AG490 (Tyrphostin AG490, the inhibitor of STAT5) group. The model was established and neuroprotection was evaluated by determining infarct volumes and conducting neurological behavioral tests. Autophagy levels in the infarct penumbra were detected using transmission electron microscopy and Western blotting. The expression of proteins in the JAK2/STAT5/BCL2 pathway was tested by Western blotting. Compared to the MCAO+saline group, the infarct volumes in the MCAO+Bre group were significantly reduced and neurological behavior improved. Breviscapine administration also significantly increased p-JAK2, p-STAT5, and BCL2 expression but decreased autolysosome numbers; it also downregulated Beclin-1 expression and the LC3II/LCI ratio. The JAK2 inhibitor AG490 reversed these effects. These findings indicate that breviscapine can improve neural recovery following ischemia through alleviating excessive autophagy and activation of the JAK2/STAT5/BCL2 axis.

Acorus calamus var. angustatus Besser: Insight into current research on ethnopharmacological use, phytochemistry, pharmacology, toxicology, and pharmacokinetics

A. calamus var. angustatus Besser is an important traditional medicinal herb commonly used in China and other Asian countries. This study is the first systematic review of the literature to thoroughly analyze the ethnopharmacological application, phytochemistry, pharmacology, toxicology and pharmacokinetic properties of A. calamus var. angustatus Besser and provides a rationale for future research and prospects for application in clinical treatment. Information on relevant studies investigating A. calamus var. angustatus Besser was collected from SciFinder, the Web of Science, PubMed, CNKI, Elsevier, ResearchGate, ACS, Flora of China, and Baidu Scholar, etc. up to December 2022. In addition, information was also obtained from Pharmacopeias, books on Chinese herbal classics, local books, as well as PhD and MS dissertations. A. calamus var. angustatus Besser has played an important role in the herbal treatment of coma, convulsion, amnesia, and dementia for thousands of years. Studies investigating the chemical constituents of A. calamus var. angustatus Besser have isolated and identified 234 small-molecule compounds and a few polysaccharides. Among them, simple phenylpropanoids represented by asarone analogues and lignans are the two main active ingredients, which can be considered characteristic chemotaxonomic markers of this herb. In vitro and in vivo pharmacological studies indicated that crude extracts and active compounds from A. calamus var. angustatus Besser display a wide range of pharmacological activities, especially as treatment for Alzheimer's disease (AD), and anticonvulsant, antidepressant-like, anxiolytic-like, anti-fatigue, anti-Parkinson, neuroprotection, and brain protection properties, providing more evidence to explain the traditional medicinal uses and ethnopharmacology. The clinical therapeutic dose of A. calamus var. angustatus Besser does not present any toxic effects, but its main active ingredients α-asarone and β-asarone at excessive dose may lead to toxicity, and in particular, their respective epoxide metabolites may exert potential toxicity to the liver. This review provides a reference and further information for the future development and clinical application of A. calamus var. angustatus Besser.

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.

Therapeutic Potential of Active Components from Acorus gramineus and Acorus tatarinowii in Neurological Disorders and Their Application in Korean Medicine

Neurological disorders represent a substantial healthcare burden worldwide due to population aging. Acorus gramineus Solander (AG) and Acorus tatarinowii Schott (AT), whose major component is asarone, have been shown to be effective in neurological disorders. This review summarized current information from preclinical and clinical studies regarding the effects of extracts and active components of AG and AT (e.g., α-asarone and β-asarone) on neurological disorders and biomedical targets, as well as the mechanisms involved. Databases, including PubMed, Embase, and RISS, were searched using the following keywords: asarone, AG, AT, and neurological disorders, including Alzheimer's disease, Parkinson's disease, depression and anxiety, epilepsy, and stroke. Meta-analyses and reviews were excluded. A total of 873 studies were collected. A total of 89 studies were selected after eliminating studies that did not meet the inclusion criteria. Research on neurological disorders widely reported that extracts or active components of AG and AT showed therapeutic efficacy in treating neurological disorders. These components also possessed a wide array of neuroprotective effects, including reduction of pathogenic protein aggregates, antiapoptotic activity, modulation of autophagy, anti-inflammatory and antioxidant activities, regulation of neurotransmitters, activation of neurogenesis, and stimulation of neurotrophic factors. Most of the included studies were preclinical studies that used in vitro and in vivo models, and only a few clinical studies have been performed. Therefore, this review summarizes the current knowledge on AG and AT therapeutic effects as a basis for further clinical studies, and clinical trials are required before these findings can be applied to human neurological disorders.

Hydroxysafflor Yellow A Alleviates Ischemic Stroke in Rats via HIF-1[Formula: see text], BNIP3, and Notch1-Mediated Inhibition of Autophagy

Stroke has become a major cause of death and disability worldwide. The cellular recycling pathway autophagy has been implicated in ischemia-induced neuronal changes, but whether autophagy plays a beneficial or detrimental role is controversial. Hydroxysafflor Yellow A (HSYA), a popular herbal medicine, is an extract of Carthamus tinctorius and is used to treat ischemic stroke (IS) in China. HSYA has been shown to prevent cardiovascular and cerebral ischemia/reperfusion injury in animal models. However, the specific active ingredients and molecular mechanisms of HSYA in IS remain unclear. Here, we investigated the effect of HSYA treatment on autophagy in a rat model of IS. IS was induced in rats by middle cerebral artery occlusion. Rats were treated once daily for 3 days with saline, HYSA, or the neuroprotective agent Edaravone. Neurobehavioral testing was performed on days 1, 2, and 3 post-surgery. Brains were removed on day 3 post-surgery for histological evaluation of infarct area, morphology, and for qRT-PCR and western blot analysis of the expression of the autophagy factor LC3 and the signaling molecules HIF-1[Formula: see text], BNIP3, and Notch1. Molecular docking studies were performed in silico to predict potential interactions between HSYA and LC3, HIF-1[Formula: see text], BNIP3, and Notch1 proteins. The result showed that HSYA treatment markedly alleviated IS-induced neurobehavioral deficits and reduced brain infarct area and tissue damage. HSYA also significantly reduced hippocampal expression levels of LC3, HIF-1[Formula: see text], BNIP3, and Notch1. The beneficial effect of HSYA was generally superior to that of Edaravone. Molecular modeling suggested that HSYA may bind strongly to HIF-1[Formula: see text], BNIP3, and Notch1 but weakly to LC3. In conclusion, HSYA inhibits post-IS autophagy induction in the brain, possibly by suppressing HIF-1[Formula: see text], BNIP3 and Notch1. HSYA may have utility as a post-IS neuroprotective agent.

Autophagy in vascular dementia and natural products with autophagy regulating activity

Chronic Cerebral Hypoperfusion(CCH)-induced vascular dementia(VD) is a common neurodegenerative disease which seriously affects the patient's quality of life. Therefore, it is critical to find an effective treatment of VD. Autophagy is a natural regulated mechanism that can remove dysfunctional proteins and organelles, however, over-activation or under-activation can of autophagy can induce the apoptosis of cells. Although autophagy plays a role in the central nervous system is unquestionable, the effects of autophagy in the ischemic brain are still controversial. Some autophagy regulators have been tested, suggesting that both activation and inhibition of autophagy can improve the cognitive function. This article reviews the role of autophagy in CCH-induced VD to discuss whether autophagy has the potential to become a target for drug development and provides several potential compounds for treating vascular dementia.

Effects of β-Asarone on Ischemic Stroke in Middle Cerebral Artery Occlusion Rats by an Nrf2-Antioxidant Response Elements (ARE) Pathway-Dependent Mechanism

Background

This study assessed the effects and underlying molecular mechanisms of β-asarone on ischemic stroke model rats.

Material/Methods

Ischemic stroke was induced by middle cerebral artery occlusion (MCAO) in rats. Before and after modeling, cognitive function was evaluated via fear conditioning test and neurological deficit was determined via Longa and Bederson scores. Following treatment with β-asarone or nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor for 20 consecutive days, the cerebral infarction was detected via TTC staining and Cresyl Violet staining in brain tissues. TUNEL staining and western blot analysis for apoptosis-related proteins were performed to assess the apoptosis of neurons. Nrf2-antioxidant response elements (ARE) pathway-related proteins were examined by RT-qPCR or western blot.

Results

The cognitive and neurological function was defective in MCAO rats. The infarction volumes and the apoptosis of cortical neurons were significantly increased in brain tissues of model rats, which were ameliorated after treatment with β-asarone. Meanwhile, the increase in pro-apoptotic proteins and decrease in anti-apoptotic proteins were found in brain tissues of model rats, which were markedly ameliorated by β-asarone treatment. However, Nrf2 inhibitor worsened the cerebral infarction and the apoptosis of neurons. Western blot results showed that β-asarone treatment activated the Nrf2-ARE pathway-related proteins in model rats, which was inhibited by Nrf2 inhibitor.

Conclusions

Our findings suggest that β-asarone treatment ameliorated the cerebral infarction in MCAO rats, which could be related to activation of the Nrf2-ARE pathway.

Revealing the Pharmacological Mechanism of Acorus tatarinowii in the Treatment of Ischemic Stroke Based on Network Pharmacology

Aim

Stroke is the second significant cause for death, with ischemic stroke (IS) being the main type threatening human being's health. Acorus tatarinowii (AT) is widely used in the treatment of Alzheimer disease, epilepsy, depression, and stroke, which leads to disorders of consciousness disease. However, the systemic mechanism of AT treating IS is unexplicit. This article is supposed to explain why AT has an effect on the treatment of IS in a comprehensive and systematic way by network pharmacology.

Methods and Materials

ADME (absorbed, distributed, metabolized, and excreted) is an important property for screening-related compounds in AT, which were screening out of TCMSP, TCMID, Chemistry Database, and literature from CNKI. Then, these targets related to screened compounds were predicted via Swiss Targets, when AT-related targets database was established. The gene targets related to IS were collected from DisGeNET and GeneCards. IS-AT is a common protein interactive network established by STRING Database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were analysed by IS-AT common target genes. Cytoscape software was used to establish a visualized network for active compounds-core targets and core target proteins-proteins interactive network. Furthermore, we drew a signal pathway picture about its effect to reveal the basic mechanism of AT against IS systematically.

Results

There were 53 active compounds screened from AT, inferring the main therapeutic substances as follows: bisasaricin, 3-cyclohexene-1-methanol-α,α,4-trimethyl,acetate, cis,cis,cis-7,10,13-hexadecatrienal, hydroxyacoronene, nerolidol, galgravin, veraguensin, 2′-o-methyl isoliquiritigenin, gamma-asarone, and alpha-asarone. We obtained 398 related targets, 63 of which were the same as the IS-related genes from targets prediction. Except for GRM2, remaining 62 target genes have an interactive relation, respectively. The top 10 degree core target genes were IL6, TNF, IL1B, TLR4, NOS3, MAPK1, PTGS2, VEGFA, JUN, and MMP9. There were more than 20 terms of biological process, 7 terms of cellular components, and 14 terms of molecular function through GO enrichment analysis and 13 terms of signal pathway from KEGG enrichment analysis based on P < 0.05.

Conclusion

AT had a therapeutic effect for ischemic via multicomponent, multitarget, and multisignal pathway, which provided a novel research aspect for AT against IS.

β-Asarone improves learning and memory in Aβ1-42-induced Alzheimer's disease rats by regulating PINK1-Parkin-mediated mitophagy

Alzheimer's disease (AD) is a chronic neurodegenerative disease that is characterized by the extracellular accumulation of β-amyloid (Aβ). Many studies have shown a close relationship between autophagy and the formation of Aβ. As AD develops and progresses, mitophagy diminishes insoluble Aβ, and mitochondrial dysfunction seems to be a determining factor in the pathogenesis of AD. In our previous study, we showed that β-asarone pharmacological effects in APP/PS1 transgenic mice, reducing Aβ expression. However, the specific mechanism of this effect remains unclear. In this study, AD model rats induced by intracerebroventricular injection of Aβ_1-42 were randomly divided into nine groups, and medical intervention was applied to the animals for 30 days. Subsequently, spatial learning and memory were evaluated by the water maze test. Bcl-2 levels in the hippocampus were determined by western blotting (WB). The protein expression of Aβ_1-42, Beclin-1, p62, PINK1, and Parkin was assessed by WB and immunohistochemistry (IHC). The data showed that after β-asarone treatment, the learning and memory of the AD rats were clearly improved compared with those of the model group. Moreover, β-asarone decreased Aβ_1-42, Bcl-2, and p62 levels but increased Beclin-1 levels compared with those in the model group. In addition, we treated a group of rats with CsA to inhibit mitophagy. β-Asarone increased PINK1 and Parkin expression compared with that in the model group. The results showed that β-asarone can improve the learning and memory of rats with Aβ_1-42-induced AD by effectively promoting PINK1-Parkin-mediated mitophagy. Taken together, these results suggest that β-asarone may have the capacity to become a pharmaceutical agent for the treatment of AD in the future.

Effect of β-asarone in normal and β-amyloid-induced Alzheimeric rats

INTRODUCTION

β-Asarone is a major component of Acorus tatarinowii Schott. It has pharmacological effects that include antihyperlipidemic, anti-inflammatory, and antioxidant activity. In the present study, the effect of β-asarone on neurodegeneration induced by intrahippocampal administration of β-amyloid was investigated in adult male Wistar rats.

MATERIAL AND METHODS

The rats were randomly divided into 9 groups: normal control, sham-operated control, β-asarone (12.5, 25, and 50 mg/kg intragastrically, daily) alone, Alzheimeric control rats (β-amyloid, intrahippocampal), β-asarone (12.5, 25, and 50 mg/kg intragastrically, daily) together with β-amyloid, and treatment was performed accordingly. Animals were injected with β-amyloid bilaterally. Animals received β-asarone daily using an intragastric tube for 50 days, starting from 30 days before administration of the β-amyloid. The rats were sacrificed and parameters of oxidative stress, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activity were measured in hippocampus homogenate. Histopathological changes were examined by Bielschowsky staining.

RESULTS

Our results showed that administration of β-asarone (25 and 50 mg/kg) significantly increased the levels of antioxidant enzymes, including SOD (1.09 ±0.02, 1.21 ±0.02, p < 0.001, respectively) and GPX (58.94 ±0.78, 68.92 ±3.64, p < 0.001, respectively) in comparison with Alzheimeric control rats (SOD and GPX level for Alzheimeric control group: 0.44 ±0.01, 35.09 ±1.15, respectively). Histopathological examination showed that β-asarone decreased cell loss in the cerebral cortex and hippocampus in Alzheimeric rats.

CONCLUSIONS

These results indicate that β-asarone is effective in providing protection against oxidative stress and neuronal damage induced by β-amyloid.

β-Asarone Increases Chemosensitivity by Inhibiting Tumor Glycolysis in Gastric Cancer

β-asarone is the main active ingredient of the Chinese herb Rhizoma Acori Tatarinowii, which exhibits a wide range of biological activities. It was confirmed to be an efficient cytotoxic agent against gastroenteric cancer cells. However, the exact mechanism of β-asarone in gastric cancer (GC) remains to be elucidated. The present study showed the inhibitory effect of β-asarone on three types of different differentiation stage GC cell lines (MGC803, SGC7901, and MKN74) in a dose-dependent manner. Meanwhile, the synergistic sensitivity of β-asarone and cisplatin was confirmed by using the median-effect principle. Flow cytometry assay revealed that under both normoxia and CoCl₂-induced hypoxia conditions, β-asarone can induce apoptosis of GC cells, which can block GC cells in the cell cycle G2/M phase, showing obvious subdiploid peak. Moreover, the activity of lactic dehydrogenase (LDH), an enzyme that plays an important role in the final step of tumor glycolysis, was significantly decreased in GC cells following treatment with β-asarone. Mechanistically, β-asarone can reduce pyruvate dehydrogenase kinase (PDK) 1, phospho(p)-PDK1, PDK4, hypoxia-inducible factor 1-α (HIF1α), c-myc, STAT5, and p-STAT5 expression, which revealed how β-asarone affects tumor glycolysis. In conclusion, the present study provided evidence in support of the hypothesis that the increase of chemotherapy sensitization by β-asarone is associated with the inhibition of tumor glycolysis.

Nose to brain drug delivery - A promising strategy for active components from herbal medicine for treating cerebral ischemia reperfusion

Cerebral ischemia reperfusion injury (CIRI), one of the major causes of death from stroke in the world, not only causes tremendous damage to human health, but also brings heavy economic burden to society. Current available treatments for CIRI, including mechanical therapies and drug therapies, are often accompanied by significant side-effects. Therefore, it is necessary to discovery new strategies for treating CIRI. Many studies have confirmed that the herbal medicine has the advantages of abundant resources, good curative effect and little side effects, which can be used as potential drug for treatment of CIRI through multiple targets. It's known that oral administration commonly has low bioavailability, and injection administration is inconvenient and unsafe. Many drugs can't delivery to brain through routine pathways due to the blood-brain-barrier (BBB). Interestingly, increasing evidences have suggested the nasal administration is a potential direct route to transport drug into brain avoiding the BBB and has the characteristics of high bioavailability for treating brain diseases. Therefore, intranasal administration can be treated as an alternative way to treat brain diseases. In the present review, effective methods to treat CIRI by using active ingredients derived from herbal medicine through nose to brain drug delivery (NBDD) are updated and discussed, and some related pharmacological mechanisms have also been emphasized. Our present study would be beneficial for the further drug development of natural agents from herbal medicines via NBDD.

β‑asarone modulates Beclin‑1, LC3 and p62 expression to attenuate Aβ40 and Aβ42 levels in APP/PS1 transgenic mice with Alzheimer's disease

Alzheimer's disease (AD) is a common neurodegenerative disease in the elderly population. Autophagy is a well-known regulator of neurodegenerative diseases and β-asarone has been discovered to have certain neuropharmacological effects. Thus, the present study aimed to analyze the potential effects of β-asarone in AD and its possible mechanism of action in relation to autophagy. The present study investigated the effects of β-asarone on the number of senile plaques and amyloid β(Aβ)₄₀, Aβ₄₂, amyloid precursor protein (APP) and Beclin-1 mRNA levels in the hippocampus of APP/presenilin-1 (PS1) transgenic mice. The possible mechanism of β-asarone on autophagy-related proteins, including Beclin-1, light chain (LC)3A, LC3B and p62 levels, and the number of autophagosomes was also investigated. Mice were divided into a normal control group, a model group, a β-asarone-treated group, a 3-MA-treated group and a rapamycin-treated group. Treatments were continuously administered to all mice for 30 days by intragastric administration. The mice, including those in the normal and model control groups, were given equal volumes of saline. It was demonstrated that β-asarone treatment reduced the number of senile plaques and autophagosomes, and decreased Aβ₄₀, Aβ₄₂, APP and Beclin-1 expression in the hippocampus of model mice compared with untreated model mice. β-asarone also inhibited LC3A/B expression levels, but increased p62 expression. It was deduced that the neuroprotective effects of β-asarone in APP/PS1 transgenic mice resulted from its inhibition of autophagy. In conclusion, the data suggested that β-asarone should be explored further as a potential therapeutic agent in AD.

β-asarone relieves chronic unpredictable mild stress induced depression by regulating the extracellular signal-regulated kinase signaling pathway

The present study aimed to investigate the effect of β-asarone treatment in a rat model of depression induced by chronic unpredictable mild stress (CUMS) and to further explore the underlying molecular mechanisms. A rat model of depression was established by subjecting rat to CUMS and treated with various concentrations of β-asarone (12.5, 25 and 50 mg/kg/day) and fluoxetine (20 mg/kg/day). Next, behavioral tests, including an open field, sucrose preference and forced swimming tests, were performed. In addition, the apoptosis of hippocampal neuronal cells was determined by flow cytometry, gene expression levels were detected by reverse transcription-quantitative polymerase chain reaction and protein levels were determined by western blot assay. The results revealed that β-asarone significantly mitigated CUMS-induced depression-like behavior, evidenced by the increased sucrose intake, crossing and rearing numbers, and decreased immobility time in the forced swimming test. Furthermore, β-asarone significantly decreased the apoptosis rate of hippocampal neuronal cells in rats subjected to CUMS. β-asarone was also found to enhance CREB, BDNF, Trk-B and Bcl-2 levels, and reduce Bad level in the hippocampus of CUMS-treated rats. In addition, the activation of extracellular signal-regulated kinase pathway inhibited by CUMS was promoted by β-asarone treatment. In conclusion, the present study findings indicated the antidepressant-like effects of β-asarone on CUMS-induced depression in rats.

Enhanced autophagy alleviates injury during hindlimb ischemia/reperfusion in mice

Previous studies examining whether autophagy has a protective or deleterious role during ischemia/reperfusion (I/R) injury have reported a varying role in different organs and remains a matter of debate. The aim of the current study was to explore the role of autophagy in hindlimb I/R injury in a murine model. An increase in apoptosis was observed in vitro, in C2C12 myoblast cells, following hypoxia/reoxygenation (H/R), while downregulation of autophagic flux was induced by chloroquine as compared with the vehicle group under hypoxia and H/R conditions. In vivo, an increase in severe damage of gastrocnemius muscles was observed in the I/R and ischemia groups compared with the control group, was more severe in the I/R group compared with the ischemia group. Electron microscopy revealed an increased number of autophagosomes in the ischemia group, whereas a reduced number was detected in the I/R group. Following administration of rapamycin, the infarct size ratio and cell apoptosis was significantly reduced, while the amount of autophagosomes significantly increased in the ischemic phase. In conclusion, autophagy is upregulated in the ischemia phase and downregulated in the reperfusion phase. Notably, upregulation of autophagy via rapamycin intervention during ischemia alleviated skeletal muscle damage, suggesting a potential protective role during hindlimb I/R injury.

Melatonin alleviates asphyxial cardiac arrest-induced cerebellar Purkinje cell death by attenuation of oxidative stress

Although multiple reports using animal models have confirmed that melatonin appears to promote neuroprotective effects following ischemia/reperfusion-induced brain injury, the relationship between its protective effects and activation of autophagy in Purkinje cells following asphyxial cardiac arrest and cardiopulmonary resuscitation (CA/CPR) remains unclear. Rats used in this study were randomly assigned to 6 groups as follows; vehicle-treated sham operated group, vehicle-treated asphyxial CA/CPR operated group, melatonin-treated sham operated group, melatonin-treated asphyxial CA/CPR operated group, PDOT (a MT2 melatonin receptor antagonist) plus (+) melatonin-treated sham operated group and PDOT+melatonin-treated asphyxial CA/CPR operated group. Melatonin (20 mg/kg, i.p., 4 times before CA and 3 times after CA) treatment significantly improved survival rate and neurological deficit compared with the vehicle-treated asphyxial CA/CPR rats (survival rates ≥40% vs 10%), showing that melatonin treatment exhibited protective effect against asphyxial CA/CPR-induced Purkinje cell death. The protective effect of melatonin against CA/CPR-induced Purkinje cell death paralleled a remarkable attenuation of autophagy-like processes (Beclin-1, Atg7 and LC3), as well as a dramatic reduction in superoxide anion radical (O₂·-), intense enhancements of CuZn superoxide dismutase (SOD1) and MnSOD (SOD2) expressions. Furthermore, the protective effect was notably reversed by treatment with PDOT, which is a selective MT2 antagonist. In brief, melatonin conferred neuroprotection against asphyxial CA/CPR-induced Purkinje cell death via inhibiting autophagic activation by reducing expressions of O₂·- and increasing expressions of antioxidant enzymes, and suggests that MT2 is involved in neuroprotective effect of melatonin against Purkinje cell death caused by asphyxial CA/CPR.

Beraprost sodium preconditioning prevents inflammation, apoptosis, and autophagy during hepatic ischemia-reperfusion injury in mice via the P38 and JNK pathways

OBJECTIVE

The goal of this study was to determine the effects of beraprost sodium (BPS) preconditioning on hepatic ischemia-reperfusion (IR) injury and its underlying mechanisms of action.

MATERIALS AND METHODS

Mice were randomly divided into sham, IR, IR+BPS (50 µg/kg), and IR+BPS (100 µg/kg) groups. Saline or BPS was given to the mice by daily gavage for 1 week before the hepatic IR model was established. Liver tissues and orbital blood were collected at 2, 8, and 24 hours after reperfusion for the determination of liver enzymes, inflammatory mediators, apoptosis- and autophagy-related proteins, key proteins in P38 and c-Jun N-terminal kinase (JNK) cascades, and evaluation of liver histopathology.

RESULTS

BPS preconditioning effectively reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, improved pathological damage, ameliorated production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and affected expressions of Bax, Bcl-2, Caspase-3, Caspase-8, and Caspase-9, microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, and P62. The protective effects of BPS preconditioning were associated with reduced P38 and JNK phosphorylation.

CONCLUSION

BPS preconditioning ameliorated hepatic IR injury by suppressing inflammation, apoptosis, and autophagy, partially via inhibiting activation of the P38 and JNK cascades.

Calcium/calmodulin-dependent protein kinase kinase β is neuroprotective in stroke in aged mice

Stroke is a devastating neurological disease and the leading cause of long-term disability, particularly in the elderly. Calcium/calmodulin-dependent protein kinase kinase β (CaMKK β) is a major kinase activated by elevated levels of intracellular calcium. Our previous findings in young mice have suggested that CaMKK β is neuroprotective as KO mice had worse stroke outcomes. Because age is an important determinant of stroke outcome, we evaluated the functional role of CaMKK β in stroke in aged mice. We used middle cerebral artery occlusion to induce stroke in aged wild-type (WT) and CaMKK β KO male mice. Lentiviral vectors carrying CaMKK β (LV-CaMKK β) were used to overexpress CaMKK β in the mouse brain. Baseline levels of CaMKK β in the aged brain were significantly lower than those in young mice. LV-CaMKK β treatment reduced infarcts and neurological deficits assessed 3 days after stroke. In chronic survival experiments, CaMKK β KO mice showed increased tissue loss in the ipsilateral hemisphere 3 weeks after stroke. In addition, KO mice showed poorer functional recovery during the 3-week survival period, as measured by the rotarod test, corner test, locomotor activity assay, and novel object recognition test, compared with WT controls. The loss of blood-brain barrier proteins, inactivation of survival gene expression such as B-cell lymphoma 2 (Bcl-2) and an increase in inflammatory cytokines in the serum were observed after stroke with CaMKK β inhibition. We demonstrate that CaMKK β is neuroprotective in stroke in aged mice. Therefore, our data suggest that CaMKK β may be a potential target for reducing long-term disability after stroke.

mTOR/autophagy pathway in the hippocampus of rats suffering intermittent hypoxia preconditioning and global cerebral ischemia-reperfusion

We explored the role of mTOR/autophagy pathway in the aggravation of cerebral ischemia-reperfusion nerve injury caused by intermittent hypoxia. Eighty male wistar rats were divided into four groups by the random number method: sham operation group (SO group, n=20), cerebral ischemia-reperfusion group (I/R group, n=20), intermittent hypoxia and cerebral ischemia-reperfusion group (IH+I/R group, n=20), intermittent hypoxia and cerebral ischemia-reperfusion group plus mTOR inhibitor group (inhibitor group, n=20). The results showed that compared with the SO group, HE staining showed structural damage of neurons at each time point, the immunohistochemical assay showed an increasing number of mTOR and beclin1 immune-positive cells (P<0.05) and RT-PCR showed enhanced expression of mTOR and beclin1 protein in the I/R group (P<0.05). Compared with the I/R group, HE staining showed exacerbating structural damage of neurons at each time point, the immunohistochemical assay showed an increasing number of mTOR and beclin1 immune-positive cells (P<0.05) and RT-PCR showed enhanced expression of mTOR and beclin1 protein in the IH+I/R group (P<0.05). Compared with the IH+I/R group, HE staining showed remissive structural damage of neurons at each time point, the immunohistochemical assay showed a decreasing number of mTOR immune-positive cells and a rising number of beclin1immune-positive cells (P<0.05) and RT-PCR showed weakened expression of mTOR protein and enhanced expression of beclin1 protein in the inhibitor group (P<0.05). Thence, the present study indicated that intermittent hypoxia preconditioning can aggravate the nerve injury of the global cerebral ischemia-reperfusion model, and the mechanism is associated with the activation of mTOR/autophagy pathway.

β-asarone inhibited cell growth and promoted autophagy via P53/Bcl-2/Bclin-1 and P53/AMPK/mTOR pathways in Human Glioma U251 cells

Glioma is the most common type of primary brain tumor and has an undesirable prognosis. Autophagy plays an important role in cancer therapy, but it is effect is still not definite. P53 is an important tumor suppressor gene and protein that is closely to autophagy. Our aim was to study the effect of β-asarone on inhibiting cell proliferation in human glioma U251 cells and to detect the effect of the inhibition on autophagy through the P53 signal pathway. For cell growth, the cells were divided into four groups: the model, β-asarone, temozolomide (TMZ), and co-administration groups. For cell autoghapy and the P53 pathway, the cells were divided into six groups: the model, β-asarone, 3MA, Rapa, Pifithrin-µ, and NSC groups. The counting Kit-8 assay and flow cytometry (FCM) were then used to measure the cell proliferation and cycle. Electron microscopy was used to observe autophagosome formation. Cell immunohistochemistry/-immunofluorescence, FCM and Western blot (WB) were used to examine the expression of Beclin-1 and P53. The levels of P53 and GAPDH mRNA were detected by RT-PCR. Using WB, we determined autophagy-related proteins Beclin-1, LC3-II/I, and P62 and those of the P53 pathway-related proteins P53, Bcl-2, mTOR, P-mTOR, AMPK, P-AMPK, and GAPDH. We got the results that β-asarone changed the cellular morphology, inhibited cell proliferation, and enhanced the expression of P53, LC3-II/I, Beclin-1, AMPK, and pAMPK while inhibiting the expression of P62, Bcl-2, mTOR, and pmTOR. All the data suggested that β-asarone could reduce the cell proliferation and promote autophagy possible via the P53 pathway in U251 cells.

Pharmacology and toxicology of α- and β-Asarone: A review of preclinical evidence

BACKGROUND

Asarone is one of the most researched phytochemicals and is mainly present in the Acorus species and Guatteria gaumeri Greenman. In preclinical studies, both α- and β-asarone have been reported to have numerous pharmacological activities and at the same time, many studies have also revealed the toxicity of α- and β-asarone.

PURPOSE

The purpose of this comprehensive review is to compile and analyze the information related to the pharmacokinetic, pharmacological, and toxicological studies reported on α- and β-asarone using preclinical in vitro and in vivo models. Besides, the molecular targets and mechanism(s) involved in the biological activities of α- and β-asarone were discussed.

METHODS

Databases including PubMed, ScienceDirect and Google scholar were searched and the literature from the year 1960 to January 2017 was retrieved using keywords such as α-asarone, β-asarone, pharmacokinetics, toxicology, pharmacological activities (e.g. depression, anxiety).

RESULTS

Based on the data obtained from the literature search, the pharmacokinetic studies of α- and β-asarone revealed that their oral bioavailability in rodents is poor with a short plasma half-life. Moreover, the metabolism of α- and β-asarone occurs mainly through cytochrome-P450 pathways. Besides, both α- and/or β-asarone possess a wide range of pharmacological activities such as antidepressant, antianxiety, anti-Alzheimer's, anti-Parkinson's, antiepileptic, anticancer, antihyperlipidemic, antithrombotic, anticholestatic and radioprotective activities through its interaction with multiple molecular targets. Importantly, the toxicological studies revealed that both α- and β-asarone can cause hepatomas and might possess mutagenicity, genotoxicity, and teratogenicity.

CONCLUSIONS

Taken together, further preclinical studies are required to confirm the pharmacological properties of α-asarone against depression, anxiety, Parkinson's disease, psychosis, drug dependence, pain, inflammation, cholestasis and thrombosis. Besides, the anticancer effect of β-asarone should be further studied in different types of cancers using in vivo models. Moreover, further dose-dependent in vivo studies are required to confirm the toxicity of α- and β-asarone. Overall, this extensive review provides a detailed information on the preclinical pharmacological and toxicological activities of α-and β-asarone and this could be very useful for researchers who wish to conduct further preclinical studies using α- and β-asarone.

Amorphous silica nanoparticles trigger vascular endothelial cell injury through apoptosis and autophagy via reactive oxygen species-mediated MAPK/Bcl-2 and PI3K/Akt/mTOR signaling

Environmental exposure to silica nanoparticles (SiNPs) is inevitable due to their widespread application in industrial, commercial, and biomedical fields. In recent years, most investigators focus on the evaluation of cardiovascular effects of SiNPs in vivo and in vitro. Endothelial injury and dysfunction is now hypothesized to be a dominant mechanism in the development of cardiovascular diseases. This study aimed to explore interaction of SiNPs with endothelial cells, and extensively investigate the exact effects of reactive oxygen species (ROS) on the signaling molecules and cytotoxicity involved in SiNPs-induced endothelial injury. Significant induction of cytotoxicity as well as oxidative stress, apoptosis, and autophagy was observed in human umbilical vein endothelial cells following the SiNPs exposure (P<0.05). The oxidative stress was induced by ROS generation, leading to redox imbalance and lipid peroxidation. SiNPs induced mitochondrial dysfunction, characterized by membrane potential collapse, and elevated Bax and declined bcl-2 expression, ultimately leading to apoptosis, and also increased number of autophagosomes and autophagy marker proteins, such as LC3 and p62. Phosphorylated ERK, PI3K, Akt, and mTOR were significantly decreased, but phosphorylated JNK and p38 MAPK were increased in SiNPs-exposed endothelial cells. In contrast, all of these stimulation phenomena were effectively inhibited by N-acetylcysteine. The N-acetylcysteine supplement attenuated SiNPs-induced endothelial toxicity through inhibition of apoptosis and autophagy via MAPK/Bcl-2 and PI3K/Akt/mTOR signaling, as well as suppression of intracellular ROS property via activating antioxidant enzyme and Nrf2 signaling. In summary, the results demonstrated that SiNPs triggered autophagy and apoptosis via ROS-mediated MAPK/Bcl-2 and PI3K/Akt/mTOR signaling in endothelial cells, and subsequently disturbed the endothelial homeostasis and impaired endothelium. Our findings may provide experimental evidence and explanation for cardiovascular diseases triggered by SiNPs. Furthermore, results hint that the application of antioxidant may provide a novel way for safer use of nanomaterials.

β-asarone improves learning and memory and reduces Acetyl Cholinesterase and Beta-amyloid 42 levels in APP/PS1 transgenic mice by regulating Beclin-1-dependent autophagy

Alzheimer's disease (AD) is the most common neurodegenerative disorder in the elderly, and studies have suggested that β-asarone has pharmacological effects on beta-amyloid (Aβ) injected in the rat hippocampus. However, the effect of β-asarone on autophagy in the APP/PS1 transgenic mouse is unreported. APP/PS1 transgenic mice were randomly divided into six groups (n=10/group): an untreated group, an Aricept-treated group, a 3-MA-treated group, a rapamycin-treated group, an LY294002-treated group, a β-asarone-treated group. The control group consisted of wild-type C57BL/6 mice. All treatments were administered to the mice for 30 days. Spatial learning and memory were assessed by water maze, passive avoidance, and step-down tests. AChE and Aβ₄₂ levels in the hippocampus were determined by ELISA. p-Akt, p-mTOR, and LC3B expression were detected by flow cytometry. The expression of p-Akt, p-mTOR, Beclin-1, and p62 proteins was assessed by western blot. Changes in autophagy were viewed using a transmission electron microscope. APP and Beclin-1 mRNA levels were measured by Real-Time PCR. The learning and memory of APP/PS1 transgenic mice were improved significantly after β-asarone treatment compared with the untreated group. In addition, β-asarone treatment reduced AChE and Aβ₄₂ levels, increased p-mTOR and p62 expression, decreased p-Akt, Beclin-1, and LC3B expression, decreased the number of autophagosomes and reduced APP mRNA and Beclin-1 mRNA levels compared with the untreated group. That is, β-asarone treatment can improve the learning and memory abilities of APP/PS1 transgenic mouse by inhibiting Beclin-1-dependent autophagy via the PI3K/Akt/mTOR pathway.

Shengmai injection attenuates the cerebral ischemia/reperfusion induced autophagy via modulation of the AMPK, mTOR and JNK pathways

Context Shengmai injection (SMI) is a patented Chinese medicine originated from the ancient Chinese herbal compound Shengmai san, which is used extensively for the treatment of cardiovascular and cerebrovascular disease in the clinic. Objective To determine the neuroprotective effect of SMI, we investigated the effect of SMI on cerebral ischemia/reperfusion (I/R) injury in mice as well as the mechanisms underlying this effect. Materials and methods Right middle cerebral artery was occluded by inserting a thread through internal carotid artery for 1 h, and then reperfused for 24 h in mice. The neuroprotective effects were determined using transmission electron microscopic examination, the evaluation of infarct volume, neurological deficits and water brain content. Related mechanisms were evaluated by immunofluorescence staining and western blotting. SMI was injected intraperitoneally after 1 h of ischemia at doses of 1.42, 2.84 and 5.68 g/kg. The control group received saline as the SMI vehicle. Results Results showed that SMI (1.42, 2.84 and 5.68 g/kg) could significantly reduce the infarct volume, SMI (5.68 g/kg) could also significantly improve the neurological deficits, decreased brain water content, as well as the neuronal morphological changes. SMI (5.68g/kg) could significantly inhibit the expression of autophagy-related proteins: Beclin1 and LC3. It also reduced the increase in LC3-positive cells. SMI (5.68 g/kg) remarkably inhibited the phosphorylation of adenosine monophosphate activated protein kinase (AMPK), and down-regulated the phosphorylation of mammalian target of rapamycin (mTOR) and Jun N-terminal kinase (JNK) after 24 h of reperfusion. Discussion and conclusion The results indicate that SMI provides remarkable protection against cerebral ischemia/reperfusion injury, which may be partly due to the inhibition of autophagy and related signalling pathways.

Beta-asarone protects against MPTP-induced Parkinson's disease via regulating long non-coding RNA MALAT1 and inhibiting α-synuclein protein expression

OBJECTIVE

Numerous long non-coding RNAs (lncRNA) have been identified in neurodegenerative disorders including Parkinson's disease (PD). Emerging evidence demonstrates that β-asarone functions as neuroprotective effects in both in vitro and in vivo models. However, the role of β-asarone and its potential mechanism in PD remain not completely clear.

METHODS

MPTP-induced PD mouse model and SH-SY5Y cells subjected to MPP+ as its in vitro model were used to evaluate the effects of β-asarone on PD. LncRNA MALAT1 and α-synuclein expression were determined by real-time PCR and western blot methods.

RESULTS

β-Asarone significantly increased the TH+ cells number and decreased the expression levels of MALAT1 and α-synuclein in midbrain tissue of PD mice. RNA pull-down and immunoprecipitation assays confirmed that MALAT1 associated with α-synuclein, leading to the increased stability of α-synuclein and its expression in SH-SY5Y cells. β-asarone elevated the viability of cells exposed to MPP+. Either overexpressed MALAT1 or α-synuclein could canceled the protective effect of β-asarone on cell viability. In PD mice, pcDNA-MALAT1 also decreased the TH+ cells number and increased the α-synuclein expression in PD mice with treatment of β-asarone.

CONCLUSION

β-Asarone functions as a neuroprotective effect in both in vivo and in vitro models of PD via regulating MALAT1 and α-synuclein expression.

Autophagy in acute brain injury

Autophagy is an evolutionarily ancient mechanism that ensures the lysosomal degradation of old, supernumerary or ectopic cytoplasmic entities. Most eukaryotic cells, including neurons, rely on proficient autophagic responses for the maintenance of homeostasis in response to stress. Accordingly, autophagy mediates neuroprotective effects following some forms of acute brain damage, including methamphetamine intoxication, spinal cord injury and subarachnoid haemorrhage. In some other circumstances, however, the autophagic machinery precipitates a peculiar form of cell death (known as autosis) that contributes to the aetiology of other types of acute brain damage, such as neonatal asphyxia. Here, we dissect the context-specific impact of autophagy on non-infectious acute brain injury, emphasizing the possible therapeutic application of pharmacological activators and inhibitors of this catabolic process for neuroprotection.

Autophagy in cerebral ischemia and the effects of traditional Chinese medicine

Autophagy is a lysosome-mediated degradation process for non-essential or damaged cellular constituents, playing an important homeostatic role in cell survival, differentiation and development to maintain homeostasis. Autophagy is involved in tumors as well as neurodegenerative, cardiovascular and cerebrovascular diseases. Recently, active compounds from traditional Chinese medicine (TCM) have been found to modulate the levels of autophagy in tumor cells, nerve cells, myocardial cells and endothelial cells. Ischemic stroke is a major cause of neurological disability and places a heavy burden on family and society. Regaining function can significantly reduce dependence and improve the quality of life of stroke survivors. In healthy cells, autophagy plays a key role in adapting to nutritional deprivation and eliminating aggregated proteins, however inappropriate activation of autophagy may lead to cell death in cerebral ischemia. This paper reviews the process and the molecular basis of autophagy, as well as its roles in cerebral ischemia and the roles of TCM in modulating its activity.

15d-prostaglandin J2 protects cortical neurons against oxygen-glucose deprivation/reoxygenation injury: involvement of inhibiting autophagy through upregulation of Bcl-2

We have previously shown that PPAR-γ agonist 15d-PGJ2 inhibited neuronal autophagy after cerebral ischemia/reperfusion injury. However, the underlying mechanism of its regulatory role in neuronal autophagy remains unclear. This study was designed to test the hypothesis that 15d-PGJ2 upregulated Bcl-2 which binds to Beclin 1, and thereby inhibits autophagy. We performed cell viability assay, cytotoxicity assay, western blot, and co-immunoprecipitation to analyze autophagy activities in vitro model of oxygen-glucose deprivation/reoxygenation (OGD/R). OGD/R induced autophagy in cultured cortical neurons. 15d-PGJ2 treatment significantly decreased LC3-II/LC3-I ratio and Beclin 1 expression, but increased p62 expression. Autophagic inhibitor 3-methyladenine decreased LC3-II levels, increased neuronal cell viability, and mimicked some protective effect of 15d-PGJ2 against OGD/R injury. OGD/R-induced autophagy coincided with decreases in Bcl-2 expression and increases in Beclin 1 expression. 15d-PGJ2 treatment upregulated Bcl-2 expression and decreased Beclin 1 expression, and inhibit the dissociation of Beclin1 from Bcl-2 significantly. Bcl-2 siRNA abrogated the effect of 15d-PGJ2 on Beclin 1, LC3-II and p62, and influence cell viability and LDH level, while scRNA did not. PPAR-γ agonist 15d-PGJ2 exerts neuroprotection partially via inhibiting neuronal autophagy after OGD/R injury. The inhibition of autophagy by 15d-PGJ2 is mediated through upregulation of Bcl-2.

Hepatotoxic potential of asarones: in vitro evaluation of hepatotoxicity and quantitative determination in herbal products

α and β asarones are natural constituents of some aromatic plants, especially species of the genus Acorus (Araceae). In addition to reports of beneficial properties of asarones, genotoxicity and carcinogenicity are also reported. Due to potential toxic effects of β-asarone, a limit of exposure from herbal products of ~2 μg/kg body weight/day has been set temporarily until a full benefit/risk assessment has been carried out by the European Medicines Agency. Therefore, it is important to monitor levels of β-asarone in herbal products. In this study, we developed a simple, rapid and validated GC-MS method for quantitative determination of asarones and applied it in 20 pediatric herbal products after detecting high concentrations of β-asarone in a product suspected to be implicated in hepatotoxicity in a 3 month old infant. Furthermore, targeted toxicological effects were further investigated in human hepatocytes (THLE-2 cells) by employing various in vitro assays, with the goal of elucidating possible mechanisms for the observed toxicity. Results showed that some of the products contained as much as 4-25 times greater amounts of β-asarone than the recommended levels. In 4 of 10 samples found to contain asarones, the presence of asarones could not be linked to the labeled ingredients, possibly due to poor quality control. Cell-based investigations in THLE-2 cells confirmed the cytotoxicity of β-asarone (IC50 = 40.0 ± 2.0 μg/mL) which was associated with significant lipid peroxidation and glutathione depletion. This observed cytotoxic effect is likely due to induction of oxidative stress by asarones. Overall, the results of this study ascertained the usability of this GC-MS method for the quantitative determination of asarones from herbal products, and shed light on the importance of controlling the concentration of potentially toxic asarones in herbal products to safeguard consumer safety, especially when the target consumers are young children. Further investigations of the toxicity of asarones are warranted.

Autophagy upregulation and apoptosis downregulation in DAHP and triptolide treated cerebral ischemia

It has previously been demonstrated that ischemic stroke activates autophagy pathways; however, the mechanism remains unclear. The aim of this study is to further investigate the role that autophagy plays in cerebral ischemia. 2, 4-diamino-6-hydroxy-pyrimidine (DAHP), for its nitric oxide synthase (NOS) inhibiting neuroprotective effect, and triptolide (TP), for its anti-inflammatory property, were selected to administer pre middle cerebral artery occlusion (MCAO). The drugs were administered 12 hours prior to MCAO. Both magnetic resonance imaging (MRI) and 2, 3, 5-triphenyltetrazolium chloride (TTC) staining showed that the drugs reduce the area of infarction. Immunoblotting analysis revealed increases in Beclin-1 and myeloid cell leukelia-1(Mcl-1) in treated rats. This could be a contributing factor to the reduction in autophagy induced damage. Immunochemistry and western blot showed that mTOR expression in treated rats was marginally different 24 h after injury, and this could also be significant in the mechanism. Furthermore, terminal deoxynucleotidyl transferase- (TdT-) mediated dUTP nick end labeling (TUNEL) staining proved that the drugs are effective in reducing apoptosis. The upregulation of Beclin-1 and Mcl-1 and downregulation of Bcl-2, caspase-3, and the Bcl-2/Beclin-1 ratio infer that the neuroprotective effect of DAHP and TP act via the mediation of autophagy and apoptosis pathways.

N-acetylcysteine attenuates ischemia-reperfusion-induced apoptosis and autophagy in mouse liver via regulation of the ROS/JNK/Bcl-2 pathway

BACKGROUND

Hepatic ischemia-reperfusion injury (HIRI) remains a pivotal clinical problem after hemorrhagic shock, transplantation, and some types of toxic hepatic injury. Apoptosis and autophagy play important roles in cell death during HIRI. It is also known that N-acetylcysteine (NAC) has significant pharmacologic effects on HIRI including elimination of reactive oxygen species (ROS) and attenuation of hepatic apoptosis. However, the effects of NAC on HIRI-induced autophagy have not been reported. In this study, we evaluated the effects of NAC on autophagy and apoptosis in HIRI, and explored the possible mechanism involved.

METHODS

A mouse model of segmental (70%) hepatic warm ischemia was adopted to determine hepatic injury. NAC (150 mg/kg), a hepatoprotection agent, was administered before surgery. We hypothesized that the mechanism of NAC may involve the ROS/JNK/Bcl-2 pathway. We evaluated the expression of JNK, P-JNK, Bcl-2, Beclin 1 and LC3 by western blotting and immunohistochemical staining. Autophagosomes were evaluated by transmission electron microscopy (TEM).

RESULTS

We found that ALT, AST and pathological changes were significantly improved in the NAC group. Western blotting analysis showed that the expression levels of Beclin 1 and LC3 were significantly decreased in NAC-treated mice. In addition, JNK, p-JNK, Bax, TNF-α, NF-κB, IL2, IL6 and levels were also decreased in NAC-treated mice.

CONCLUSION

NAC can prevent HIRI-induced autophagy and apoptosis by influencing the JNK signal pathway. The mechanism is likely to involve attenuation of JNK and p-JNK via scavenged ROS, an indirect increase in Bcl-2 level, and finally an alteration in the balance of Beclin 1 and Bcl-2.

A combination of four active compounds alleviates cerebral ischemia-reperfusion injury in correlation with inhibition of autophagy and modulation of AMPK/mTOR and JNK pathways

SMXZF is a combination of Rb1, Rg1, schizandrin, and DT-13 (6:9:5:4) derived from Sheng-mai San, a widely used Chinese traditional medicine for the treatment of cardiovascular and cerebral diseases. The present study explores the inhibitory effects and signaling pathways of SMXZF on autophagy induced by cerebral ischemia-reperfusion injury. Male C57BL/6 mice were subjected to ischemia-reperfusion insult by right middle cerebral artery occlusion (MCAO) for 1 hr with subsequent 24 hr reperfusion. Three doses of SMXZF (4.5, 9, and 18 mg/kg) were administered intraperitoneally (i.p.) after ischemia for 1 hr. An autophagic inhibitor, 3-methyladenine (3-MA; 300 μg/kg), was administered i.p. 20 min before ischemia as a positive drug. We found that SMXZF significantly increased cerebral blood flow and reduced the infarct volume, brain water content, and the neurological deficits in a dose-dependent manner. Similar to the positive control, SMXZF at 18 mg/kg also significantly inhibited autophagosome formation. Immunofluorescence staining and Western blotting demonstrated that SMXZF could significantly decrease the expression levels of beclin1 and microtubule-associated protein 1 light chain 3. SMXZF also remarkably inhibited the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) as well as the expression of c-Jun N-terminal kinase (JNK) and its phosphorylation induced by 24 hr reperfusion. Finally, we demonstrated that the optimal administration time of SMXZF was at the early period of reperfusion. This study reveals that SMXZF displays neuroprotective effect against focal ischemia-reperfusion injury, possibly associated with autophagy inactivation through AMPK/mTOR and JNK pathways.