β-asarone inhibits autophagy by activating the PI3K/Akt/mTOR pathway in a rat model of depression in Parkinson's disease

OBJECTIVE

It is unclear whether β-asarone has a good antidepressant effect and what is the main mechanism in Depression in Parkinson's disease (DPD) model rats.

METHODS

In this study, DPD model rats were screened from 6-OHDA induced rats by sucrose preference test (SPT) and forced swimming test (FST). DPD model rats were divided into eight groups: model group, pramipexole group, β-asarone low-dose group (β-asarone 7.5 group), β-asarone medium-dose group (β-asarone 15 group), β-asarone high-dose group (β-asarone 30 group), 3-MA group, rapamycin group, and PI3K inhibitor group. 28 days after the end of treatment, open field test (OFT), SPT and FST were conducted in rats. The level of α-synuclein (α-syn) in the striatum was determined by enzyme-linked immunosorbent assay (ELISA). The expression of Beclin-1, p62 in the striatum was determined by western blot. The expression of PI3K, p-PI3K, Akt, p-Akt, mTOR, p-mTOR, Beclin-1, and p62 in the hippocampus was determined by western blot. The spine density of neurons in the hippocampus was detected by golgi staining.

RESULTS

The results showed that 4-week oral administration of β-asarone improve the motor and depressive symptoms of DPD model rats, and decrease the content of α-syn in the striatum. β-asarone inhibited the expression of autophagy in the striatum of DPD model rats. Furthermore, β-asarone decreased the levels of Beclin-1 protein, increased the expression of p62, p-PI3K, p-AKT, and p-mTOR, and improved the density of neuron dendritic spine in the hippocampus.

CONCLUSIONS

We concluded that β-asarone might improve the behavior of DPD model rats by activating the PI3K/Akt/mTOR pathway, inhibiting autophagy and protecting neuron.

Inhibitory effects of β-asarone on lncRNA BACE1-mediated induction of autophagy in a model of Alzheimer's disease

The primary aim of this study was to examine the correlation between the formation of Aβ plaques and autophagy, which is regulated by β-asarone and the lncRNA BACE1-AS. Additionally, the study sought to explore potential targets of the drug in inhibiting the deposition of toxic AD-related proteins and restoring impaired mitochondrial and autophagic functions. SHY5Y cells were utilized to construct a stable Alzheimer's disease (AD) model, followed by the utilization of interference and overexpression lentiviruses targeting BACE1-AS to establish a cell model. The cells were categorized into five groups, including a normal group, siRNA/BACE1 group, and β-asarone group. The fluorescence quantitative PCR technique was employed to assess the disparity in BACE1 mRNA expression, while changes in immunofluorescence (IF) were observed to determine the stable interference titre and action time of the lentiviruses. Additionally, western blotting (WB) and fluorescence quantitative PCR were employed to evaluate the expression of proteins and mRNAs associated with AD and autophagy. The findings demonstrated a significant elevation in BACE1 expression levels in brain tissue among individuals with AD compared to those without the condition. Moreover, the results indicated that the introduction of β-asarone led to an increase in the expression of the BACE1-AS gene in the cell group transfected with plasmid H12732. Furthermore, it was observed that β-asarone enhanced the expression levels of shRNA and BACE1 after 72 h. In contrast, β-asarone suppressed the expression of PS1, Aβ, BACE1, APP, and p62, while promoting the expression of syn, LC3 I/II, and Beclin-1. Based on these findings, it can be concluded that β-Asarone exerts a comprehensive influence on the expression of proteins associated with AD and synaptic function. β-Asarone exhibits the potential to mitigate Aβ deposition by impeding the expression of lncBACE1, thereby facilitating autophagy through the suppression of BACE1's inhibitory impact on autophagy. This complements the self-enhancing effect of autophagy.

β-asarone improves cognitive impairment and alleviates autophagy in mice with vascular dementia via the cAMP/PKA/CREB pathway

BACKGROUND

Vascular dementia (VD) is the second most common type of dementia after Alzheimer's disease. β-asarone, a major component of Acorus tatarinowii Schott, is important in neurodegenerative and neurovascular diseases. Studies have confirmed that β-asarone can mitigate autophagy and reduce damage in hypoxic cells. We also reported that β-asarone improves learning and memory. This study further clarifies whether β-asarone attenuates cerebral ischaemic injury by acting through the cAMP/PKA/CREB pathway in VD model mice.

METHODS

Here, genes and potential pathways that may be targeted by β-asarone for the treatment of transient cerebral ischaemia (TCI) and cognitive impairment (CI) were obtained using network pharmacology. The two-vessel occlusion method was used to establish the VD model. The Morris water maze test was used to evaluate the effects on memory. Then, the protein levels of mitofusin-2 (Mfn2), brain-derived neurotrophic factor (BDNF), optic atrophy 1 (OPA1), cyclic adenosine monophosphate (cAMP), myelin basic protein (MBP), matrix metalloproteinase-9 (MMP9) and neuron specific enolase (NSE) were determined by ELISA. The levels of superoxide dismutase (SOD) and malonaldehyde (MDA) were measured using commercial kits. Then, qRT-PCR was employed to investigate the expression of the candidate genes screened from the protein-protein interaction (PPI) network. Furthermore, the expression of the autophagy-related proteins Beclin-1, (microtubule-associated protein light chain 3) LC3, p62, postsynaptic density protein 95 (PSD95), protein kinase A (PKA), pPKA, cyclic-AMP response binding protein (CREB), and pCREB was determined by western blotting. The expression of autophagy-related proteins, PSD95 and translocase of outer mitochondrial membrane 20 (TOM20) was determined by immunofluorescence analyses.

RESULTS

The network pharmacological analysis showed 234 targets related to β-asarone, 1,118 genes related to TCI and 2,039 genes associated with CI. Our results confirm that β-asarone treatment not only alleviated brain damage in the VD model by improving mitochondrial and synaptic function, reducing neuronal injury and upregulating the expression of antioxidants but also effectively improved the cognitive behaviour of VD model mice. Moreover, β-asarone downregulated VD-induced RELA and CCND1 mRNA expression. In addition, we validated that β-asarone increased the phosphorylation of PKA and CREB and upregulated cAMP protein expression. The results showed that the cAMP/PKA/CREB signalling pathway was upregulated. Moreover, β-asarone administration decreased the protein expression levels of Beclin-1 and LC3 and increased the expression levels of p62 in VD model mice.

CONCLUSIONS

β-asarone inhibits Beclin-1-dependent autophagy and upregulates the cAMP/PKA/CREB signalling pathway to attenuate mitochondrial and synaptic damage from cerebral ischaemia and improve learning and cognitive abilities in VD model mice.

Nose to brain delivery of Astragaloside IV by β-Asarone modified chitosan nanoparticles for multiple sclerosis therapy

Multiple sclerosis (MS), an autoimmune disease, has been considered an inflammatory disorder of the central nervous system (CNS) with demyelination and axonal damage. Although there are certain first-line therapies to treat MS, their unsatisfactory efficacy is partly due to the limited CNS access after systemic administration. Besides, there is an urgent need to treat MS by enhancing remyelination or neuroprotection, or dampen the activity of microglia. Astragaloside IV (ASI) bears anti-inflammatory, antioxidant, remyelination and neuroprotective activity. While its poor permeability, relatively high molecular weight and low lipophilicity restrict it to reach the brain. Therefore, β-asarone modified ASI loaded chitosan nanoparticles (ASI-βCS-NP) were prepared to enhance the nose-to-brain delivery and therapeutic effects of ASI on EAE mice. The prepared ASI-βCS-NP showed mean size of about 120 nm, and zeta potential from +19 to +25 mV. DiR-βCS-NP was confirmed with good nose-to-brain targeting ability. After intranasal administration, the ASI-βCS-NP significantly reduced behavioral scores, decreased weight loss, suppressed inflammatory infiltration and astrocyte/microglial activation, reduced demyelination and increased remyelination on a mice EAE model. Our findings indicate that ASI-βCS-NP may be a potent treatment for MS after nose-to-brain drug delivery.

Synergetic effect of β-asarone and cannabidiol against Aβ aggregation in vitro and in vivo

Alzheimer's disease (AD) is a complex and multifactorial neurodegenerative disorder, and it is unlikely that any single drug or intervention will be very successful. The pathophysiology of Alzheimer's disease involves a range of complicated biological processes, including the accumulation of beta-amyloid protein and tau protein. Given the complexity of AD and amyloid accumulation, a combination of interventions remains to be further explored. Here, we investigated the potential of combining β-asarone and cannabidiol (CBD) as a treatment for AD. The study analyzed the combined effects of these two phytochemicals on beta-amyloid (Aβ) protein aggregation and toxicity in bulk solution, in cells as well as in C.elegans. We detailed the morphological and size changes of Aβ40 aggregates in the presence of β-asarone and cannabidiol. More importantly, the presence of both compounds synergistically inhibited apoptosis and downregulated relative gene expression in cells, and that it may also slow aging, decrease the rate of paralysis, enhance learning capacity, and boost autophagy activity in C.elegans. Our studies suggest that multiple drugs, like β-asarone and CBD, may be potentially developed as a medicinal adjunct in the treatment of AD, although further clinical trials are needed to determine the efficacy and safety of this combination treatment in humans.

β-Asarone Alleviates High-Glucose-Induced Oxidative Damage via Inhibition of ROS Generation and Inactivation of the NF-κB/NLRP3 Inflammasome Pathway in Human Retinal Pigment Epithelial Cells

Diabetic retinopathy (DR) is the leading cause of vision loss and a major complication of diabetes. Hyperglycemia-induced accumulation of reactive oxygen species (ROS) is an important risk factor for DR. β-asarone, a major component of volatile oil extracted from Acori graminei Rhizoma, exerts antioxidant effects; however, its efficacy in DR remains unknown. In this study, we investigated whether β-asarone inhibits high-glucose (HG)-induced oxidative damage in human retinal pigment epithelial (RPE) ARPE-19 cells. We found that β-asarone significantly alleviated cytotoxicity, apoptosis, and DNA damage in HG-treated ARPE-19 cells via scavenging of ROS generation. β-Asarone also significantly attenuated the excessive accumulation of lactate dehydrogenase and mitochondrial ROS by increasing the manganese superoxide dismutase and glutathione activities. HG conditions markedly increased the release of interleukin (IL)-1β and IL-18 and upregulated their protein expression and activation of the nuclear factor-kappa B (NF-κB) signaling pathway, whereas β-asarone reversed these effects. Moreover, expression levels of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome multiprotein complex molecules, including thioredoxin-interacting protein, NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain, and cysteinyl aspartate-specific proteinase-1, were increased in ARPE-19 cells under HG conditions. However, their expression levels remained similar to those in the control group in the presence of β-asarone. Therefore, β-asarone protects RPE cells from HG-induced injury by blocking ROS generation and NF-κB/NLRP3 inflammasome activation, indicating its potential as a therapeutic agent for DR treatment.

Concept of dementia (Nisy ā n) in Unani system of medicine and scientific validation of an important Unani pharmacopoeial preparation 'Majoon Vaj' for its management: a review

OBJECTIVES

This review focused on the concept of dementia in the Unani system of medicine and comprehensive, updated information on Majoon Vaj about the phytochemistry, nootropic, CNS activities and provide insights into potential opportunities for future research.

METHODS

The classical literature on Majoon Vaj for its anti-dementic properties, and therapeutic uses were gathered from nearly thirteen classical Unani books including Unani Pharmacopoeia. The information of pharmacognosy, phytochemical and pharmacological activities of Majoon Vaj and its ingredient was collected by browsing the Internet (PubMed, ScienceDirect, Wiley online library, Google Scholar, ResearchGate). The relevant primary sources were probed, analysed, and included in this review. The keywords used to browse were Majoon Vaj, Dementia, Nootropic, Acorus calamus, Piper nigram, Zingiber officinalis, Nigella sativa, Carum carvi, Plumbago zeylanica, and β-asarone. Relevant Sources were gathered up to July 2021, and the chemical structures were drawn using ACD/ChemSketch software. The species name and synonyms were checked with WFO (2021): World Flora online (http://www.worldfloraonline.org) an updated version of 'The Plant List.'

RESULTS

Majoon Vaj contains an excess of bioactive compounds e.g., alkaloids, phenols, flavonoids, tannins, diterpenes, coumarins, carbohydrates, and fixed oils and its ingredients possess broad pharmacological properties, including cognitive-enhancing, neuroprotective, anti-inflammatory, antioxidant and antimicrobial properties.

CONCLUSIONS

The literature of Unani medicine is quite rich in discussing the pathophysiological basis of memory disorders. It argues that memory, retention, and retrieval are regulated by a complex process involving various faculties. Majoon Vaj seems to have great potential for therapeutic applications in the treatment of dementia and thus encourage more preclinical and clinical trials in this field.

β-asarone inhibits the migration, invasion, and EMT of bladder cancer through activating ER stress

BACKGROUND

β-asarone (β-as), a compound extracted from Acorus calamus, has been found to have anticancer effects on a variety of human cancers. However, the potential effect of β-as on bladder cancer (BCa) remains unknown.

METHODS

After exposure to β-as, migration, invasion, and epithelial-mesenchymal transition (EMT) of BCa were determined by wound healing, transwell, and Western blot assays. Expression of proteins involved in the EMT and ER stress were explored by Western blot assays. Nude mouse xenograft model was served as the model system in vivo.

RESULTS

The migration, invasion, and EMT of BCa were significantly inhibited after β-as treatment. Further experiments revealed that endoplasmic reticulum (ER) stress is involved in β-as-mediated metastasis inhibition. In addition, β-as significantly up-regulated activating transcription factor 6 (ATF6), a branch of ER stress, and promoted its Golgi cleavage and nuclear localization. ATF6 silencing attenuated β-as-mediated metastasis and EMT inhibition in BCa cells.

CONCLUSION

Our data suggests that β-as inhibits migration, invasion, and EMT of BCa by activating the ATF6 branch of ER stress. Thus, β-as represents a potential candidate for BCa treatment.

β-asarone prolongs sleep via regulating the level of glutamate in the PVN

People of all ages could suffer from sleep disorders, which are increasingly recognized as common manifestations of neurologic disease. Acorus tatarinowii is a herb that has been used in traditional medicine to promote sleep. β-asarone, as the main component of volatile oil obtained from Acorus tatarinowii, may be the main contributor to the sleeping-promoting efficacy of Acorus tatarinowii. In the study, adult male C57BL/6 mice were administered β-asarone at 12.5 mg/kg, 25 mg/kg, and 50 mg/kg. Behavioral experiments showed that β-asarone at 25 mg/kg could significantly improve sleep duration. It was also observed that the proportion of NREM (Non-Rapid Eye Movement) sleep increased considerably after administration of β-asarone. In the PVN (paraventricular nucleus of hypothalamus) region of the hypothalamus, it was observed that the glutamate content decreased after β-asarone treatment. At the same time, the expression of VGLUT2 (vesicular glutamate transporters 2) decreased while the expression of GAD65 (glutamic acid decarboxylase 65) and GABARAP (GABA Type A Receptor-Associated Protein) increased in the hypothalamus, suggesting that β-asarone may suppress arousal by reducing glutamate and promoting transformation of glutamate to the inhibitory neurotransmitter GABA (γ-aminobutyric acid). This study is the first to focus on the association between β-asarone and sleep, shedding perspectives for pharmacological applications of β-asarone and providing a new direction for future research.

The Toxicity, Sublethal Effects, and Biochemical Mechanism of β-Asarone, a Potential Plant-Derived Insecticide, against Bemisia tabaci

Bemisia tabaci is a threat to agriculture worldwide because of its potential to cause devastating damage to various crops. β-asarone is a bioactive pesticidal chemical originating from Acorus calamus (or “Sweet Flag”) plants, and it displays significant lethal effects against insect pests. In this study, we established a baseline of susceptibility to β-asarone from China and patterns of cross-resistance to other popular insecticides. We found that all the 12 field-collected B. tabaci populations exhibited high susceptibility to β-asarone, and there was no cross-resistance detected for other tested insecticides. We subsequently evaluated the sublethal effects of β-asarone on physiology and biochemistry via LC₂₅ treatment (4.7 mg/L). LC₂₅ of β-asarone resulted in prolonged developmental duration and decreased survival rates in B. tabaci nymphs, pseudopupae, and adults. Significant reductions in oviposition duration, fecundity, and hatchability were also observed. Additionally, the metabolic enzyme activity and expression profiles of selected cytochrome P450 monooxygenase (P450) genes following the LC₂₅ treatment of β-asarone suggest that enhanced detoxification via P450s could be involved in the observed sublethal effects. These findings demonstrate the strong toxicity and significant sublethal effects of β-asarone on B. tabaci and suggest that the induced overexpression of P450 genes could be associated with the response to β-asarone.

β-Asarone Attenuates Aβ-Induced Neuronal Damage in PC12 Cells Overexpressing APPswe by Restoring Autophagic Flux

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive memory damage and cognitive dysfunction. Studies have shown that defective autophagic flux is associated with neuronal dysfunction. Modulating autophagic activity represents a potential method of combating AD. In Chinese medicine, Acori Tatarinowii Rhizoma is used to treat dementia and amnesia. β-Asarone, an active component of this rhizome can protect PC12 cells from Aβ-induced injury and modulate expression of autophagy factors. However, its cytoprotective mechanisms have yet to be discerned. It is unclear whether β-asarone affects autophagic flux and, if it does, whether this effect can alleviate Aβ cell damage. In the present study, we constructed APPswe-overexpressing PC12 cell line as a cell model of Aβ-induced damage and assessed expression of autophagic flux-related proteins as well as the number and morphology of autophagosomes and autolysosomes. Our results show that β-asarone decreases the expression levels of Beclin-1, p62, LC3-Ⅱ, and Aβ_1-42. β-Asarone reduced the number of autophagosomes and increased the number of autolysosomes, as determined by confocal laser scanning microscopy and transmission electron microscopy. Our results suggest that β-asarone can protect PC12 cells from Aβ-induced damage by promoting autophagic flux, which may be achieved by enhancing autophagosome-lysosome fusion and/or lysosome function.

β-Asarone Ameliorates β-Amyloid-Induced Neurotoxicity in PC12 Cells by Activating P13K/Akt/Nrf2 Signaling Pathway

Accumulation of β-amyloid (Aβ) causes oxidative stress, which is the major pathological mechanism in Alzheimer's disease (AD). β-asarone could reduce Aβ-induced oxidative stress and neuronal damage, but the molecular mechanism remains elusive. In this study, we used an Aβ-stimulated PC12 cell model to explore the neuroprotective effects and potential mechanisms of β-asarone. The results showed that β-asarone could improve cell viability and weaken cell damage and apoptosis. β-asarone could also decrease the level of ROS and MDA; increase the level of SOD, CAT, and GSH-PX; and ameliorate the mitochondrial membrane potential. Furthermore, β-asarone could promote the expression of Nrf2 and HO-1 by upregulating the level of PI3K/Akt phosphorylation. In conclusion, β-asarone could exert neuroprotective effects by modulating the P13K/Akt/Nrf2 signaling pathway. β-asarone might be a promising therapy for AD.

β-Asarone suppresses TNF-α expression through DNA methylation and c-Jun-mediated transcription modulation in scratch-injured neuronal cells

This study aimed to investigate the role and possible mechanism of β-asarone in regulating neuronal apoptosis and axonal regeneration. A scratch injury was applied to cell cultures of mouse primary cortical neurons to mimic neuronal injury. The neuronal apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling staining and western blot analysis of apoptosis-related proteins. The axonal regeneration was assessed by immunofluorescent staining of β-tubulin III and western blot analysis of axonal markers. In the results, β-asarone inhibited neuronal apoptosis and promoted axonal regeneration by suppressing tumor necrosis factor-α (TNF-α) expression in scratch-injured mouse neuronal cells. Research investigating the molecular mechanisms by which β-asarone inhibited TNF-α expression showed that, on the one hand, β-asarone suppressed the JNK/c-Jun pathway and thus transcriptionally inhibited TNF-α expression; on the other hand, β-asarone induced expression of UHRF1 that recruited DNMT1 to induce TNF-α promoter methylation and subsequently decreased the messenger RNA expression of TNF-α. In conclusion, β-asarone suppresses TNF-α expression through DNA methylation and c-Jun-mediated transcription modulation in scratch-injured neuronal cells.

β-asarone suppresses HCT116 colon cancer cell proliferation and liver metastasis in part by activating the innate immune system

Studies have revealed that β-asarone exerts a powerful inhibitory effect on the proliferation of human cancer cells. The authors' previous study demonstrated that β-asarone could induce LoVo colon cancer cell apoptosis in vitro and in vivo, indicating its anticancer properties. The present study aimed to determine the antineoplastic effect of β-asarone in HCT116 colon cancer cells. An in vitro proliferation assay using a real time cell analyzer demonstrated that β-asarone effectively decreased HCT116 cell proliferation in a dose-dependent manner. Bioinformatics analysis revealed that differentially expressed genes following β-asarone inhibition were involved in the ‘cell cycle’, ‘cell division’, ‘cell proliferation’ and ‘apoptosis’. Subsequently, a xenograft assay evidenced the inhibitory effect of β-asarone on the growth of HCT116 tumors in vivo. Further detection of immune-associated cytokines and cells suggested that β-asarone might be involved in the antitumor immune response by stimulating granulocyte-colony stimulating factor and increasing the number of macrophage cells in the spleen. Additionally, a murine model of splenic-transplantation verified the strong suppressive role of β-asarone in colon cancer liver metastasis in vivo. Taken together, the results of the current study revealed that β-asarone decreased HCT116 colon cancer cell proliferation and liver metastasis potentially by activating the innate immune system, supporting the multi-system regulation theory and providing a basis for further mechanistic studies on colon cancer.

Knockdown of CYP301B1 and CYP6AX1v2 increases the susceptibility of the brown planthopper to beta-asarone, a potential plant-derived insecticide

The cytochrome P450 monooxygenases of insects play crucial roles in the metabolic detoxification of insecticides. Our previous finding showed that two cytochrome P450 genes, both CYP301B1 and CYP6AX1v2, in the BPH underwent overexpression due to β-asarone. In this study, we investigated the molecular characteristics, expression patterns and functions of these two cytochrome P450 genes. The results showed that CYP301B1 had the highest expression level in the eggs, while CYP6AX1v2 was expressed in macropterous female adults. Moreover, the expression level of CYP301B1 in the head was higher than that in the integument, fat body and gut. The expression level of CYP6AX1v2 in the fat body and gut was higher than that in head and integument. Importantly, silencing CYP301B1 and CYP6AX1v2 separately could increase the sensitivity, resulting in significant higher mortality of BPH following treatment with β-asarone. Our findings indicated that CYP301B1 and CYP6AX1v2 could contribute to the resistance of BPH to β-asarone, and these two genes may be involved in the detoxification metabolism of β-asarone in BPH.

[Preparation and in vitro quality evaluation of self-microemulsion co-loaded with tenuifolin and β-asarone]

To prepare and optimize the self-microemulsion co-loaded with tenuifolin and β-asarone(TF/ASA-SMEDDS) and evaluate its quality. The prescription compositions of TF/ASA-SMEDDS were screened by solubility test, single factor test and pseudo-tern-ary phase diagram, and the prescriptions were further optimized by Box-Behnken response surface method, with the drug loading and particle size as the evaluation indexes. Then the optimized TF/ASA-SMEDDS was evaluated for emulsified appearance, particle size, morphology and drug release in vitro. The optimized prescription for TF/ASA-SMEDDS was as follows: caprylic citrate triglyceride polyoxyethylene castor oil-glycerol(10.8∶39.2∶50), drug loading of(5.563±0.065) mg·g~(-1) for tenuifolin and(5.526±0.022) mg·g~(-1) for β-asarone; uniform and transparent pan-blue nanoemulsion can be formed after emulsification, with particle size of(28.84±0.44) nm. TEM showed that TF/ASA-SMEDDS can form spherical droplets with a uniform particle size after emulsification; In vitro release test results showed that the drug release rate and cumulative release of tenuifolin and β-asarone were significantly improved. The preparation process of TF/ASA-SMEDDS was simple and can effectively improve in vitro release of tenuifolin and β-asarone.

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 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 Inhibits Amyloid-β by Promoting Autophagy in a Cell Model of Alzheimer's Disease

Alzheimer's disease (AD) is one of the most common types of dementia that causes memory, thinking, and behavior problems. The most important feature of AD is the gradual irreversible loss of cognitive ability through the formation of amyloid β (Aβ) plaques and neurofibrillary tangles composed of tau protein. The metabolism of Aβ and tau proteins is closely related to and is affected by autophagy. Current research speculates that autophagy dysfunction leads to an increase in harmful proteins in AD. β-Asarone is the main constituent of Acorus tatarinowii Schott and has important effects on the central nervous system. In this paper, we primarily explored the effects of β-asarone on the clearance of noxious proteins and the associated potential mechanisms via autophagy in a PC12 cell AD model. A CCK-8 assay and LDH experiments were used to assess cell viability/toxicity, and SPiDER-βGal was used to detect cellular senescence. The important proteins associated with the pathogenesis of AD including APP, PS1, Aβ, BACE1, and SYN1 were analyzed by immunofluorescence (IF) and Western blot analysis. Antimycin A (A3) and cyclosporine A (CSA) were selected as the activators and inhibitors of autophagy, respectively. LC3, BECN, P62, PINK1, and Parkin protein expression were also examined by IF and Western blot analysis. The data showed that β-asarone administration significantly dose-dependently increased cell proliferation and decreased cytotoxicity; moreover, β-asarone inhibited SA-βGal and improved cell senescence. The results further showed that, compared to the model, APP, PS1, Aβ, BACE1, and p62 were reduced, while SYN1, BECN1, and LC3 were increased after treatment with β-asarone. The results of Canonical Correlation Analysis (CCA) showed a highly significant relationship between the pathological factors of AD and the protein expression of autophagy. In conclusion, our study demonstrated that β-asarone can inhibit Aβ, and this effect may occur by promoting autophagy in a cell model of AD.

Candidate detoxification-related genes in brown planthopper, Nilaparvata lugens, in response to β-asarone based on transcriptomic analysis

Nilaparvata lugens(Stål) is a serious pest of rice and has evolved different levels of resistance against most chemical pesticides. β-asarone is the main bioactive insecticidal compound of Acorus calamus L. that shows strong insecticidal activity against pests. In this study, we conducted a bioassay experiment to determine the contact toxicity of β-asarone to N. lugens nymphs. The LD₃₀ sublethal dose was 0.106 μg per nymph, with 95% confidence limits of 0.070-0.140 μg. We applied the LD₃₀ concentration of β-asarone to nymphs for 24 h or 72 h and then performed a transcriptome sequence analysis by referencing the N. lugens genome to characterize the variation. The transcriptomic analysis showed that several GO terms and KEGG pathways presented significant changes. Individually, 126 differentially expressed genes (DEGs), including 72 upregulated and 54 downregulated genes, were identified at 24 h, and 1771 DEGs, including 882 upregulated and 889 downregulated genes, were identified at 72 h. From the DEGs, we identified a total of 40 detoxification-related genes, including eighteen Cytochrome P450 monooxygenase genes (P450s), three Glutathione S-transferase genes, one Carboxylesterase gene, twelve UDP-glucosyltransferases and six ATP-binding cassette genes. We selected the eighteen P450s for subsequent verification by quantitative PCR. These findings indicated that β-asarone presented strong contact toxicity to N. lugens nymphs and induced obvious variation of detoxification-related genes that may be involved in the response to β-asarone.

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.

Cytotoxic effects of β-asarone on Sf9 insect cells

β-Asarone is the predominant component of the essential oil of rhizomes of Acorus calamus Linn ( Sweet flag). Although rhizome extracts from this plant have long been used for insect pest control, their cytotoxic effects on insect cells are not well understood. In this study, we evaluated the potency of β-asarone as a natural insecticide by using a Spodoptera frugiperda cell line (Sf9). To assess the cytotoxic effects of β-asarone on Sf9 cells, we observed morphologic changes in treated cells and performed a cell proliferation assay and a DNA fragmentation assay. After 24 and 48 h of treatment with β-asarone, the proliferation of the Sf9 cells was inhibited in a dose-dependent manner, with IC₅₀ values of 0.558 mg/ml at 24 h and 0.253 mg/ml at 48 h. Morphologic changes in β-asarone-treated cells were typical of apoptosis and included loss of adhesion, cell shrinkage, and small apoptotic bodies. The DNA laddering present in β-asarone-treated SF9 cells and annexin V assay confirmed that this compound can induce apoptosis in insect cells. Together, these findings suggest that apoptosis induction may be one mechanism through which β-asarone inhibits the proliferation of insect cells and thus exerts insecticidal effects.

[Protective effect of β-asarone on AD rat model induced by intracerebroventricular injection of Aβ₁₋₄₂ combined 2-VO and its mechanism]

This study was aimed to investigate the protective effect and mechanism of β-asarone on the animal model of Alzheimer's disease(AD) which was induced by intracerebroventricular injection of Aβ₁₋₄₂ combined cerebral ischemia. One hundred and five rats were randomly divided into seven groups including sham-operated group, AD model group, β-asarone 10 mg•kg⁻¹ group, β-asarone 20 mg•kg⁻¹ group, β-asarone 30 mg•kg⁻¹ group, donepezil group(0.75 mg•kg⁻¹) and Ginkgo biloba extract group(24 mg•kg⁻¹). Rats' learning and memory abilities, cerebric regional blood flow, pathological changes in hippocampal CA1 region, the expression level of HIF-1α and serum CAT, SOD and MDA level were detected 4 weeks later. The results showed that the application of intracerebroventricular injection of Aβ₁₋₄₂ joint 2-VO could lead to rats' dysfunction of learning and memory, decrease in regional cerebral blood flow. Neurons in CA1 region were arranged in disorder, and amyloid deposition was increased. The number of cerebral cortical cells expressing HIF-1α was increased as well. The level of serum CAT and SOD decreased, while level of serum MDA increased. However these symptoms were improved by 20 mg•kg⁻¹ and 30 mg•kg⁻¹ β-asarone. The results indicated that β-asarone could effectively relieve the symptoms of the AD model induced by intracerebroventricular injection of Aβ₁₋₄₂ combined cerebral ischemia, and the potential mechanism might be that it could attenuate damage of MDA to the body by improving the level of CAT and SOD, meanwhile the level of HIF-1α decreased as the decline of hyperoxide which might attenuate its damage to neuron, so it finally achieved alleviating Alzheimer's disease.

β-Asarone Induces Apoptosis and Cell Cycle Arrest of Human Glioma U251 Cells via Suppression of HnRNP A2/B1-Mediated Pathway In Vitro and In Vivo

HnRNP A2/B1 has been found to be an oncogenic protein strongly related to the growth of human glioma cells. Herein, β-asarone, the main component in the volatile oil of Acori tatarinowii Rhizoma, inhibited the cell viability, proliferation, and colony formation ability of U251 cells. Moreover, β-asarone induced apoptosis and cell cycle arrest at the G1 phase. Notably, β-asarone suppressed the expression of hnRNP A2/B1 and hnRNPA2/B1 overexpression remarkably reversed β-asarone-mediated apoptosis and cell cycle arrest. Importantly, β-asarone promoted the alternative splicing of Bcl-x by enhancing the ratio of Bcl-xS/Bcl-xL. Meanwhile, hnRNPA2/B1 overexpression mitigated the promoting effect of β-asarone on the alternative splicing of Bcl-x. β-asarone also regulated the level of the key proteins involved in the death receptor pathway and mitochondrial apoptosis pathway. Additionally, β-asarone modulated the cell cycle-related proteins p21, p27, Cdc25A, cyclin D, cyclin E, and CDK2. Finally, β-asarone inhibited tumor growth and induced apoptosis in nude mice bearing U251 tumor xenografts. β-asarone also suppressed the hnRNP A2/B1 expression, enhanced the expression of cleaved-caspase 3 and p27 and the ratio of Bcl-xS/Bcl-xL, and reduced the expression of CDK2 in U251 xenografts. Together, β-asarone-induced apoptosis and cell cycle arrest of U251 cells may be related to the suppression of hnRNPA2/B1-mediated signaling pathway.

β-Asarone Inhibits Invasion and EMT in Human Glioma U251 Cells by Suppressing Splicing Factor HnRNP A2/B1

β-asarone, the main component in the volatile oil of Acori tatarinowii Rhizoma, has been found to possess antitumor activity. However, its effect and mechanisms against tumor invasion and epithelial–mesenchymal transition (EMT) are still unclear. In this study, no or less cytotoxicity was caused by β-asarone within 0–120 μM in human glioma U251 cells for 48 h. β-asarone (30 and 60 μM) inhibited the migration of U251 cells in the wound healing assay, suppressed the invasion of U251 cells in the Boyden chamber invasion assay, and inhibited the adhesion of U251 cells onto the Matrigel. Moreover, β-asarone suppressed EMT with the up-regulation of E-cadherin and the down-regulation of vimentin. HnRNP A2/B1, a well-characterized oncogenic protein, was shown at a high basal level in U251 cells and β-asarone reduced hnRNP A2/B1 expression in a concentration and time-dependent way. Importantly, hnRNP A2/B1 overexpression significantly counteracted the inhibition of β-asarone on the migration, invasion, and adhesion of U251 cells and reversed the modulation of EMT markers by β-asarone. Additionally, β-asarone decreased the MMP-9 and p-STAT3 in U251 cells, which was also reversed by hnRNP A2/B1 overexpression. Together, our results suggest that hnRNP A2/B1 may be a potential molecular target underlying the inhibitory effect of β-asarone on invasion and EMT in glioma cells.

Combined application of tenuigenin and β-asarone improved the efficacy of memantine in treating moderate-to-severe Alzheimer's disease

Background

Alzheimer’s disease (AD) is a slowly progressive neurodegenerative disease which cannot be cured at present. The aim of this study was to assess whether the combined application of β-asarone and tenuigenin could improve the efficacy of memantine in treating moderate-to-severe AD.

Patients and methods

One hundred and fifty-two patients with moderate-to-severe AD were recruited and assigned to two groups. Patients in the experiment group received β-asarone 10 mg/d, tenuigenin 10 mg/d, and memantine 5–20 mg/d. Patients in the control group only received memantine 5–20 mg/d. The Mini Mental State Examination (MMSE), Clinical Dementia Rating Scale (CDR), and Activities of Daily Living (ADL) were used to assess the therapeutic effects. The drug-related adverse events were used to assess the safety and acceptability. Treatment was continued for 12 weeks.

Results

After 12 weeks of treatment, the average MMSE scores, ADL scores, and CDR scores in the two groups were significantly improved. But, compared to the control group, the experimental group had a significantly higher average MMSE score (p<0.00001), lower average ADL score (p=0.00002), and lower average CDR score (p=0.030). Meanwhile, the rates of adverse events were similar between the two groups. Subgroup analysis indicated that the most likely candidates to benefit from this novel method might be the 60–74-years-old male patients with moderate AD.

Conclusion

These results demonstrated that the combined application of β-asarone and tenuigenin could improve the efficacy of memantine in treating moderate-to-severe AD. The clinical applicability of this novel method showed greater promise and should be further explored.

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.

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.

Neuroprotective effect of β-asarone against Alzheimer's disease: regulation of synaptic plasticity by increased expression of SYP and GluR1

Aim

β-asarone, an active component of Acori graminei rhizome, has been reported to have neuroprotective effects in Alzheimer’s disease. As the underlying mechanism is not known, we investigated the neuroprotective effects of β-asarone in an APP/PS1 double transgenic mouse model and in NG108 cells.

Materials and methods

APPswe/PS1dE9 double transgenic male mice were randomly assigned to a model group, β-asarone treatment groups (21.2, 42.4, or 84.8 mg/kg/d), or donepezil treatment group (2 mg/kg/d). Donepezil treatment was a positive control, and background- and age-matched wild-type B6 mice were an external control group. β-asarone (95.6% purity) was dissolved in 0.8% Tween 80 and administered by gavage once daily for 2.5 months. Control and model animals received an equal volume of vehicle. After 2.5 months of treatment, behavior of all animals was evaluated in a Morris water maze. Expression of synaptophysin (SYP) and glutamatergic receptor 1 (G1uR1) in the hippocampus and cortex of the double transgenic mice was assayed by Western blotting. The antagonistic effects of β-asarone against amyloid-β peptide (Aβ) were investigated in vitro in the NG108-15 cell line. After 24 hours of incubation, cells were treated with 10 μm Aβ with or without β-asarone at different concentrations (6.25, 12.5, or 25 μM) for an additional 36 hours. The cytotoxicity of β-asarone was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay of cell viability, and cell morphology was evaluated by bright-field microscopy after 24 hours of treatment. The expression of SYP and GluR1 in cells was detected by Western blot assay in the hippocampus and brain cortex tissues of mice.

Results

β-asarone at a high dose reduced escape latency and upregulated SYP and GluR1 expression at both medium and high doses. Cell morphology evaluation showed that β-asarone treatment did not result in obvious cell surface spots and cytoplasmic granularity. β-asarone had a dose-dependent effect on cell proliferation.

Conclusion

β-asarone antagonized the Aβ neurotoxicity in vivo, improved the learning and memory ability of APP/PS1 mice, and increased the expression of SYP and GluR1 both in vivo and in vitro. Thus, β-asarone may be a potential drug for the treatment of Alzheimer’s disease.

[Protective effect of β-asarone on PC12 cells injury induced by Aβ₁₋₄₂ astrocytic activation]

This study was aimed to investigate the protective effect and mechanism of β-asarone on PC12 cells injury induced byAβ₁₋₄₂ activated astrocytes, and provide experimental basis for β-asarone application in the prevention and control of Alzheimer's disease (AD). Firstly, RA-h and PC12 cells were co-cultured in the special transwell chamber, and the Real time cell analysis (RTCA) system was used to real-time observe its effect on PC12 cells survival rate in the co-culture system after astrocytes injury induced by Aβ₁₋₄₂. The best intervention time of β-asarone was selected according to the survival curve and parameters generated automatically. β-asarone with different concentrations was used for intervention on astrocytes, then the changes of PC12 cells survival rate in the co-culture system were observed. Secondly, MTT assay was used to detect the effect of Aβ₁₋₄₂ on PC12 cells survival rate as well as the intervention effect of β-asarone, and verify the testing results of RTCA. The levels of IL-1β, TNF-α and BDNF in culture media of the lower chamber were detected by ELISA. The NF-κB activity and phosphorylation levels of ERK, p38 and JNK were detected by Western blot. Results showed that β-asarone (55.5 mg•L⁻¹) could significantly slowdown the decline of PC12 cells survival rate caused by Aβ₁₋₄₂-induced RA-h activation (P<0.01), significantly reduce the levels of IL-1β, TNF-α and the phosphorylation levels of ERK, p38 and JNK in culture media of the lower chamber (P<0.01). β-asarone(166.7 mg•L⁻¹) could promote the release of BDNF in culture media of the lower chamber(P<0.05). These results indicated that Aβ₁₋₄₂ could induce RA-h activation and its release of IL-1β, TNF-α and other inflammatory factors to aggravate the PC12 cells injury; β-asarone could reduce the levels of IL-1β, TNF-α, promote the release of BDNF, and inhibit the NF-κB activity as well as phosphorylation levels of ERK, p38 and JNK protein in PC12 cells.

β-asarone prevents Aβ25-35-induced inflammatory responses and autophagy in SH-SY5Y cells: down expression Beclin-1, LC3B and up expression Bcl-2

Alzheimer's disease (AD) is a chronic progressive neurodegenerative disorder. Inflammatory responses and autophagy have been implicated in the amyloid-β (Aβ) aggregation in Alzheimer's disease. Although major evidence indicates that macro autophagy is involved in the pathogenesis of AD, its exact role is still unclear. β-asarone, a major component of Acorus tatarinowii Schott, has various neuroprotective effects. However, little is known about the protection of β-asarone against inflammation response and autophagy. In the present study, we investigated the neuroprotective effects of β-asarone on Aβ25-35 induced inflammatory responses and autophagy, and the possible mechanism. Our results showed that β-asarone attenuated inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 production. Meanwhile, β-asarone could significantly reduce Beclin-1, LC3B and increase anti-apoptotic protein Bcl-2 level. These results showed that β-asarone protected cells from Aβ25-35 induced inflammation and attenuated autophagy via Bcl-2/Beclin-1 pathway. Our findings suggested that β-asarone might be a potential preventive drug for AD.

Effect of Beta-Asarone on Impairment of Spatial Working Memory and Apoptosis in the Hippocampus of Rats Exposed to Chronic Corticosterone Administration

β-asarone (BAS) is an active component of Acori graminei rhizoma, a traditional medicine used clinically in treating dementia and chronic stress in Korea. However, the cognitive effects of BAS and its mechanism of action have remained elusive. The purpose of this study was to examine whether BAS improved spatial cognitive impairment induced in rats following chronic corticosterone (CORT) administration. CORT administration (40 mg/kg, i.p., 21 days) resulted in cognitive impairment in the avoidance conditioning test (AAT) and the Morris water maze (MWM) test that was reversed by BAS (200 mg/kg, i.p). Additionally, as assessed by immunohistochemistry and RT-PCR analysis, the administration of BAS significantly alleviated memory-associated decreases in the expression levels of brain-derived neurotrophic factor (BDNF) and cAMP-response element-binding protein (CREB) proteins and mRNAs in the hippocampus. Also, BAS administration significantly restored the expression of Bax and Bcl-2 mRNAs in the hippocampus. Thus, BAS may be an effective therapeutic for learning and memory disturbances, and its neuroprotective effect was mediated, in part, by normalizing the CORT response, resulting in regulation of BDNF and CREB functions and anti-apoptosis in rats.

Protective effects of components of the Chinese herb grassleaf sweetflag rhizome on PC12 cells incubated with amyloid-beta42

The major ingredients of grassleaf sweetflag rhizome are β-asarone and eugenol, which can cross the blood-brain barrier and protect neurons. This study aimed to observe the neuroprotective effects and mechanisms of β-asarone and eugenol, components of the Chinese herb grassleaf sweetflag rhizome, on PC12 cells. First, PC12 cells were cultured with different concentrations (between 1 × 10^-10 M and 1 × 10^-5 M) of β-asarone and eugenol. Survival rates of PC12 cells were not significantly affected. Second, PC12 cells incubated with amyloid-beta42, which reduced cell survival, were cultured under the same conditions (1 × 10^-6 M β-asarone and eugenol). The survival rates of PC12 cells significantly increased, while expression levels of the mRNAs for the pro-apoptotic protein Bax decreased, and those for the anti-apoptotic protein Bcl mRNA increased. In addition, the combination of β-asarone with eugenol achieved better results than either component alone. Our experimental findings indicate that both β-asarone and eugenol protect PC12 cells through inhibiting apoptosis, and that the combination of the two is better than either alone.

Dynamic changes of five neurotransmitters and their related enzymes in various rat tissues following β-asarone and levodopa co-administration

The aim of the present study was to investigate the dynamic changes of five neurotransmitters and their associated enzymes in the rat plasma and brain tissues following the co-administration of β-asarone and levodopa (L-dopa). The rats were divided into five groups, including the control group and four treatment groups that were intragastrically co-administered β-asarone and L-dopa and sacrificed at 1, 5, 18 and 48 h, respectively. Neurotransmitter levels in the brain tissues and plasma were detected using high performance liquid chromatograph and the related enzymes of dopamine (DA) were measured using an enzyme-linked immunosorbent assay. The results indicated that the striatal levels of L-dopa and 3,4-dihydroxyphenylacetic acid (DOPAC) peaked at 1 h and then returned to the normal levels, while the striatal levels of DA were stable within 48 h. In the cortex and hippocampus tissue, L-dopa, DA, DOPAC and homovanillic acid (HVA) levels peaked at 1 h and then returned to normal levels. In the plasma, L-dopa, DA, DOPAC and HVA levels peaked at 1 h. Compared with the control group, L-dopa, DA and HVA levels were higher between 18 and 48 h, whereas the DOPAC level was lower. By contrast, no statistically significant differences were observed in the serotonin (5-HT) levels among the plasma, hippocampus, cortex and striatum. Furthermore, the DA/L-dopa ratio in the brain tissues and plasma increased in the first 5 h, while (DOPAC + HVA)/DA ratios demonstrated a significant reduction. Striatal tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase (AADC) levels were higher compared with the control group; however, catechol-O-methyltransferase (COMT) and monoamine oxidase B levels were reduced. In the rat plasma, TH and COMT peaked at 1 h, while AADC peaked at 5 h. In conclusion, the results of the present study indicate that the co-administration of L-dopa and β-asarone may be used to maintain a stable striatal DA level within 48 h. In addition, this treatment may promote DA generation by AADC and reduce the metabolism of DA by COMT.

Coadministration of β-asarone and levodopa increases dopamine in rat brain by accelerating transformation of levodopa: a different mechanism from Madopar

The aim of the present study was to investigate the effect of coadministration of β-asarone and levodopa (l-dopa) on increasing dopamine (DA) in the striatum of healthy rats. Rats were randomly divided into four groups: (i) a normal group, administered normal saline; (ii) a Madopar group, administered 75 mg/kg Madopar (l-dopa : benserazide, 4 : 1); (iii) an l-dopa group, administered 60 mg/kg l-dopa; and (iv) a group coadministered 15 mg/kg β-asarone and 60 mg/kg l-dopa. All drugs (or normal saline) were administered intragastrically twice a day for 7 days. Then, plasma and striatum concentrations of DA, l-dopa, 5-hydroxytryptamine (5-HT), homovanillic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC), tyrosine hydroxylase (TH), catechol-O-methyltransferase (COMT) and monoamine oxidase B (MAO-B) were determined. In the group coadministered β-asarone and l-dopa, there was a decline in plasma and striatal concentrations of l-dopa; however, DA and DOPAC concentrations increased in the striatum and plasma and plasma HVA concentrations increased, whereas there was no significant change in striatal levels. Concentrations of 5-HT in the striatum and plasma were similar in the coadministered and Madopar-treated groups. In addition, plasma and striatal COMT levels decreased after coadministration of β-asarone and l-dopa, whereas there were no significant differences in MAO-B concentrations among groups. Furthermore, coadministration of β-asarone and l-dopa increased plasma TH concentrations. Altogether, β-asarone affects the conversion of l-dopa to DA by modulating COMT activity and DA metabolism. The mechanism of coadministration is different from that of Madopar in Parkinson's disease (PD) treatment. Thus, the coadministration of β-asarone and l-dopa may be beneficial in the treatment of PD.

Fate of β-asarone in Ayurvedic Sodhana process of Vacha

BACKGROUND

Calamus (Acorus calamus Linn., Araceae) rhizome synonymously called sweet flag or Vacha is an aromatic herb indigenous to Central Asia and Eastern Europe. It has been used by the Ayurvedic practitioners since time immemorial for diseases ranging from weakness of memory to being used as an anthelminthic. Reports of its use have been found in books like Charak Samhita, Sushruta Samhita, etc., The major constituent of the oil of Vacha is a phenyl propanoid called β-asarone, which is reported to show carcinogenic properties. Due to the toxic effects of β-asarone, sodhana prakriya (detoxification process) has been prescribed for Vacha before its inclusion in the Ayurvedic medicines. Shodhanaprakriya (S. prakriya) of Vacha has been mentioned in the Ayurvedic texts.

OBJECTIVES

This study was undertaken with an aim to find out the mechanism involved in the S. prakriya of Vacha and also to suggest an alternate method for the conventional one.

MATERIALS AND METHODS

The conventional method was studied in the laboratory and equivalent alternate methods were designed based on the mechanism involved. Vacha samples were subjected to the conventional method as well as the alternate methods and the content of β-asarone in the different samples was monitored using Gas Chromatography technique.

RESULTS

Various alternate methods have been devised based on the mechanism involved in the S. prakriya which have given results comparable with those of the conventional method.

CONCLUSION

The scientific mechanism involved in the S. prakriya of Vacha has been established and alternate methods have been proposed.