Ligustilide improves aging-induced memory deficit by regulating mitochondrial related inflammation in SAMP8 mice

Unveiling the impact of aging on BBB and Alzheimer's disease: Factors and therapeutic implications

Alzheimer's disease (AD) is a highly prevalent neurodegenerative condition that has devastating effects on individuals, often resulting in dementia. AD is primarily defined by the presence of extracellular plaques containing insoluble β-amyloid peptide (Aβ) and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein (P-tau). In addition, individuals afflicted by these age-related illnesses experience a diminished state of health, which places significant financial strain on their loved ones. Several risk factors play a significant role in the development of AD. These factors include genetics, diet, smoking, certain diseases (such as cerebrovascular diseases, obesity, hypertension, and dyslipidemia), age, and alcohol consumption. Age-related factors are key contributors to the development of vascular-based neurodegenerative diseases such as AD. In general, the process of aging can lead to changes in the immune system's responses and can also initiate inflammation in the brain. The chronic inflammation and the inflammatory mediators found in the brain play a crucial role in the dysfunction of the blood-brain barrier (BBB). Furthermore, maintaining BBB integrity is of utmost importance in preventing a wide range of neurological disorders. Therefore, in this review, we discussed the role of age and its related factors in the breakdown of the blood-brain barrier and the development of AD. We also discussed the importance of different compounds, such as those with anti-aging properties, and other compounds that can help maintain the integrity of the blood-brain barrier in the prevention of AD. This review builds a strong correlation between age-related factors, degradation of the BBB, and its impact on AD.

Melatonin attenuates scopolamine-induced cognitive dysfunction through SIRT1/IRE1α/XBP1 pathway

BACKGROUND

The prevalence of dementia around the world is increasing, and these patients are more likely to have cognitive impairments, mood and anxiety disorders (depression, anxiety, and panic disorder), and attention deficit disorders over their lifetime. Previous studies have proven that melatonin could improve memory loss, but its specific mechanism is still confused.

METHODS

In this study, we used in vivo and in vitro models to examine the neuroprotective effect of melatonin on scopolamine (SCOP)-induced cognitive dysfunction. The behavioral tests were performed. 18F-FDG PET imaging was used to assess the metabolism of the brain. Protein expressions were determined through kit detection, Western blot, and immunofluorescence. Nissl staining was conducted to reflect neurodegeneration. MTT assay and RNAi transfection were applied to perform the in vitro experiments.

RESULTS

We found that melatonin could ameliorate SCOP-induced cognitive dysfunction and relieve anxious-like behaviors or HT22 cell damage. 18F-FDG PET-CT results showed that melatonin could improve cerebral glucose uptake in SCOP-treated mice. Melatonin restored the cholinergic function, increased the expressions of neurotrophic factors, and ameliorated oxidative stress in the brain of SCOP-treated mice. In addition, melatonin upregulated the expression of silent information regulator 1 (SIRT1), which further relieved endoplasmic reticulum (ER) stress by decreasing the expression of phosphorylate inositol-requiring enzyme (p-IRE1α) and its downstream, X-box binding protein 1 (XBP1).

CONCLUSIONS

These results indicated that melatonin could ameliorate SCOP-induced cognitive dysfunction through the SIRT1/IRE1α/XBP1 pathway. SIRT1 might be the critical target of melatonin in the treatment of dementia.

Effects of Ocimum basilicum L. Extract on Hippocampal Oxidative Stress, Inflammation, and BDNF Expression in Amnesic Aged Rats

The present study was conducted to investigate the effects of Ocimum basilicum L. (OB) extract on learning and memory impairment in aged rats. Male rats were divided into the following experimental groups: Group 1 (control): including 2 months old rats, Group 2 (aged) including 2 years old rats, Groups 3-5 (aged-OB): including 2 years old rats received 50, 100, and 150 mg/kg OB for 8 weeks by oral gavage. Aging increased the delay to find the platform but, however, decreased the time spent in the target quadrant when tested by Morris water maze (MWM). Aging also reduced the latency to enter the dark chamber in the passive avoidance (PA) test compared to the control group. Moreover, interleukin-6 (IL-6) and malondialdehyde (MDA) levels were raised in the hippocampus and cortex of aged rats. In contrast, thiol levels and enzymatic activity of superoxide dismutase (SOD) and catalase (CAT) significantly reduced. In addition, aging significantly reduced BDNF expression. Finally, OB administration reversed the mentioned effects. The current research showed that OB administration improves learning/memory impairment induced by aging. It also found that this plant extract protects the brain tissues from oxidative damage and neuroinflammation.

Ligustilide inhibits Purkinje cell ferritinophagy via the ULK1/NCOA4 pathway to attenuate valproic acid-induced autistic features

BACKGROUND

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder in which social impairment is the core symptom. Presently, there are no definitive medications to cure core symptoms of ASD, and most therapeutic strategies ameliorate ASD symptoms. Treatments with proven efficacy in autism are imminent. Ligustilide (LIG), an herbal monomer extracted from Angelica Sinensis and Chuanxiong, is mainly distributed in the cerebellum and widely used in treating neurological disorders. However, there are no studies on its effect on autistic-like phenotypes and its mechanism of action.

PURPOSE

Investigate the efficacy and mechanism of LIG in treating ASD using two Valproic acid(VPA)-exposed and BTBR T + Itpr3tf/J (BTBR) mouse models of autism.

METHODS

VPA-exposed mice and BTBR mice were given LIG for treatment, and its effect on autistic-like phenotype was detected by behavioral experiments, which included a three-chamber social test. Subsequently, RNA-Sequence(RNA-Seq) of the cerebellum was performed to observe the biological changes to search target pathways. The autophagy and ferroptosis pathways screened were verified by WB(Western Blot) assay, and the cerebellum was stained by immunofluorescence and examined by electron microscopy. To further explore the therapeutic mechanism, ULK1 agonist BL-918 was used to block the therapeutic effect of LIG to verify its target effect.

RESULTS

Our work demonstrates that LIG administration from P12-P14 improved autism-related behaviors and motor dysfunction in VPA-exposed mice. Similarly, BTBR mice showed the same improvement. RNA-Seq data identified ULK1 as the target of LIG in regulating ferritinophagy in the cerebellum of VPA-exposed mice, as evidenced by activated autophagy, increased ferritin degradation, iron overload, and lipid peroxidation. We found that VPA exposure-induced ferritinophagy occurred in the Purkinje cells, with enhanced NCOA4 and Lc3B expressions. Notably, the therapeutic effect of LIG disappeared when ULK1 was activated.

CONCLUSION

LIG treatment inhibits ferritinophagy in Purkinje cells via the ULK1/NCOA4-dependent pathway. Our study reveals for the first time that LIG treatment ameliorates autism symptoms in VPA-exposed mice by reducing aberrant Purkinje ferritinophagy. At the same time, our study complements the pathogenic mechanisms of autism and introduces new possibilities for its therapeutic options.

Ligustilide-loaded liposome ameliorates mitochondrial impairments and improves cognitive function via the PKA/AKAP1 signaling pathway in a mouse model of Alzheimer's disease

BACKGROUND

Oxidative stress is an early event in the development of Alzheimer's disease (AD) and maybe a pivotal point of interaction governing AD pathogenesis; oxidative stress contributes to metabolism imbalance, protein misfolding, neuroinflammation and apoptosis. Excess reactive oxygen species (ROS) are a major contributor to oxidative stress. As vital sources of ROS, mitochondria are also the primary targets of ROS attack. Seeking effective avenues to reduce oxidative stress has attracted increasing attention for AD intervention.

METHODS

We developed liposome-packaged Ligustilide (LIG) and investigated its effects on mitochondrial function and AD-like pathology in the APPswe/PS1dE9 (APP/PS1) mouse model of AD, and analyzed possible mechanisms.

RESULTS

We observed that LIG-loaded liposome (LIG-LPs) treatment reduced oxidative stress and β-amyloid (Aβ) deposition and mitigated cognitive impairment in APP/PS1 mice. LIG management alleviated the destruction of the inner structure in the hippocampal mitochondria and ameliorated the imbalance between mitochondrial fission and fusion in the APP/PS1 mouse brain. We showed that the decline in cAMP-dependent protein kinase A (PKA) and A-kinase anchor protein 1 for PKA (AKAP1) was associated with oxidative stress and AD-like pathology. We confirmed that LIG-mediated antioxidant properties and neuroprotection were involved in upregulating the PKA/AKAP1 signaling in APPswe cells in vitro.

CONCLUSION

Liposome packaging for LIG is relatively biosafe and can overcome the instability of LIG. LIG alleviates mitochondrial dysfunctions and cognitive impairment via the PKA/AKAP1 signaling pathway. Our results provide experimental evidence that LIG-LPs may be a promising agent for AD therapy.

Ligustilide prevents thymic immune senescence by regulating Thymosin β15-dependent spatial distribution of thymic epithelial cells

BACKGROUND

Thymus is the most crucial organ connecting immunity and aging. The progressive senescence of thymic epithelial cells (TECs) leads to the involution of thymus under aging, chronic stress and other factors. Ligustilide (LIG) is a major active component of the anti-aging Chinese herbal medicine Angelica sinensis (Oliv.) Diels, but its role in preventing TEC-based thymic aging remains elusive.

PURPOSE

This study explored the protective role of Ligustilide in alleviating ADM (adriamycin) -induced thymic immune senescence and its underlying molecular mechanisms.

METHOD

The protective effect of Ligustilide on ADM-induced thymic atrophy was examined by mouse and organotypic models, and conformed by SA-β-gal staining in TECs. The abnormal spatial distribution of TECs in the senescent thymus was analyzed using H&E, immunofluorescence and flow cytometry. The possible mechanisms of Ligustilide in ADM-induced thymic aging were elucidated by qPCR, fluorescence labeling and Western blot. The mechanism of Ligustilide was subsequently validated through actin polymerization inhibitor, genetic engineering to regulate Thymosin β15 (Tβ15) and Tβ4 expression, molecular docking and β Thymosin-G-actin cross-linking assay.

RESULTS

At a 5 mg/kg dose, Ligustilide markedly ameliorated ADM-induced weight loss and limb grip weakness in mice. It also reversed thymic damage and restored positive selection impaired by ADM. In vitro, ADM disrupted thymic structure, reduced TECs number and hindered double negative (DN) T cell differentiation. Ligustilide counteracted these effects, promoted TEC proliferation and reticular differentiation, leading to an increase in CD4+ single positive (CD4SP) T cell proportion. Mechanistically, ADM diminished the microfilament quantity in immortalized TECs (iTECs), and lowered the expression of cytoskeletal marker proteins. Molecular docking and cross-linking assay revealed that Ligustilide inhibited the protein binding between G-actin and Tβ15 by inhibiting the formation of the Tβ15-G-actin complex, thus enhancing the microfilament assembly capacity in TECs.

CONCLUSION

This study, for the first time, reveals that Ligustilide can attenuate actin depolymerization, protects TECs from ADM-induced acute aging by inhibiting the binding of Tβ15 to G-actin, thereby improving thymic immune function. Moreover, it underscores the interesting role of Ligustilide in maintaining cytoskeletal assembly and network structure of TECs, offering a novel perspective for deeper understanding of anti thymic aging.

Targeting mitophagy for neurological disorders treatment: advances in drugs and non-drug approaches

Mitochondria serve as a vital energy source for nerve cells. The mitochondrial network also acts as a defense mechanism against external stressors that can threaten the stability of the nervous system. However, excessive accumulation of damaged mitochondria can lead to neuronal death. Mitophagy is an essential pathway in the mitochondrial quality control system and can protect neurons by selectively removing damaged mitochondria. In most neurological disorders, dysfunctional mitochondria are a common feature, and drugs that target mitophagy can improve symptoms. Here, we reviewed the role of mitophagy in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, stroke, and traumatic brain injuries. We also summarized drug and non-drug approaches to promote mitophagy and described their therapeutic role in neurological disorders in order to provide valuable insight into the potential therapeutic agents available for neurological disease treatment. However, most studies on mitophagy regulation are based on preclinical research using cell and animal models, which may not accurately reflect the effects in humans. This poses a challenge to the clinical application of drugs targeting mitophagy. Additionally, these drugs may carry the risk of intolerable side effects and toxicity. Future research should focus on the development of safer and more targeted drugs for mitophagy.

Angelica acutiloba Kitagawa flower induces A549 cell pyroptosis via the NF-κB/NLRP3 pathway for anti-lung cancer effects

Angelica acutiloba Kitagawa, a traditional medicinal herb of the Umbelliferae family, has been demonstrated to have anticancer activity. In this study, we investigated the anti-lung cancer effects of two compounds extracted from A. acutiloba flowers: kaempferol-3-O-α-L-(4″-E-p-coumaroyl)-rhamnoside (KAE) and platanoside (PLA). MTT, cell colony formation, and cell migration (scratch) assays revealed that both KAE (100 μM) and PLA (50 μM and 100 μM) inhibited the viability, proliferation, and migration of A549 cells. Dichlorodihydrofluorescein diacetate assays showed that KAE and PLA also induced the generation of reactive oxygen species in A549 cells. Morphologically, A549 cells swelled and grew larger under treatment with KAE and PLA, with the most significant changes at 100 μM PLA. Fluorescence staining and measurement of lactate dehydrogenase release showed that the cells underwent pyroptosis with concomitant upregulation of interleukin (IL)-1β and IL-18. Furthermore, both KAE and PLA induced upregulation of NF-κB, PARP, NLRP3, ASC, cleaved-caspase-1, and GSDMD expression in A549 cells. Subsequent investigations unveiled that these compounds interact with NLRP3, augment NLRP3's binding affinity with ASC, and stimulate the assembly of the inflammasome, thereby inducing pyroptosis. In conclusion, KAE and PLA, two active components of A. acutiloba flower extract, had significant anti-lung cancer activities exerted through regulation of proteins related to the NLRP3 inflammasome pathway.

Exploring the therapeutic potential of natural compounds for Alzheimer's disease: Mechanisms of action and pharmacological properties

Alzheimer's Disease (AD) is a global public health priority characterized by high mortality rates in adults and an increasing prevalence in aging populations worldwide. Despite significant advancements in comprehending the pathogenesis of AD since its initial report in 1907, there remains a lack of effective curative or preventive measures for the disease. In recent years, natural compounds sourced from diverse origins have garnered considerable attention as potential therapeutic agents for AD, owing to their anti-inflammatory, antioxidant, and neuroprotective properties. This review aims to consolidate the therapeutic effects of natural compounds on AD, specifically targeting the reduction of β-amyloid (Aβ) overproduction, anti-apoptosis, autophagy, neuroinflammation, oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Notably, the identified compounds exhibiting these effects predominantly originate from plants. This review provides valuable insights into the potential of natural compounds as a reservoir of novel therapeutic agents for AD, thereby stimulating further research and contributing to the development of efficacious treatments for this devastating disease.

Hesperetin attenuates cognitive dysfunction via SIRT6/NLRP3 pathway in scopolamine-induced mice

Neuroinflammation is a critical feature in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD). Hesperetin can exert anti-inflammatory, antioxidant and other neuroprotective effects. In this study, the scopolamine (SCOP)-induced cognitive dysfunction in mice model was used to evaluate the neuroprotective effects of hesperetin. Behavioral tests (Morris water maze, open field, and novel object recognition tests) were conducted to evaluate the effect of hesperetin on cognitive dysfunction behaviors. Nissl staining and Immunofluorescence were used to evaluate hippocampal neuronal damage and microglial activation in mice. The levels of proinflammatory factors, oxidant stress, and the cholinergic neurotransmitter were detected by real-time quantitative fluorescence PCR (RT-qPCR) or biochemical reagent kits. Western blotting was used to detect the relative protein expression of the sirtuin 6 (SIRT6) / NOD-like receptor thermal protein domain associated protein 3 (NLRP3) pathway. Results showed that hesperetin could ameliorate SCOP-induced cognitive impairment and neuronal damage, and regulate the levels of cholinergic neurotransmitters in the hippocampal of AD mice. Hesperetin could also enhance antioxidant defense by regulating the levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT). Hesperetin exerted anti-neuroinflammation effects through inhibiting of microglia activation and down-regulating the mRNA transcript levels of inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Meanwhile, hesperetin could attenuate the expression of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), thioredoxin-interacting protein (TXNIP), and caspase-1 p20 and upregulate the expression of SIRT6 in SCOP-induced mice. Overall, our study suggested that hesperetin might ameliorate SCOP-induced cognitive dysfunction by improving cholinergic system dysfunction and suppressing oxidative stress and attenuating neuroinflammation via SIRT6/NLRP3 pathway in mice.

Improving behavioral test data collection and analysis in animal models with an image processing program

Behavioral studies are commonly used as a standard procedure to evaluate anxiety and depression in animal models. Recently, different methods have been developed to improve data collection and analysis of the behavioral tests. Currently available methods, including manual analysis and commercially available products, are either time-consuming or costly. The objective of this study was to improve the collection and analysis of behavioral test data in animal models by developing an image processing program. Eleven behavioral parameters were evaluated by three different methods, including (i) manual detection, (ii) commercially available TopScan software (CleverSys Inc, USA), and (iii) In-housed-developed Advanced Move Tracker (AMT) software. Results obtained from different methods were compared to validate the accuracy and efficiency of AMT. Results showed that AMT software provides highly accurate and reliable data analysis compared to other methods. Less than 5% tolerance was reported between results obtained from AMT compared to TopScan. In addition, the analysis processing time was remarkably reduced (68.3%) by using AMT compared to manual detection. Overall, the findings confirmed that AMT is an efficient program for automated data analysis, significantly enhancing research outcomes through accurate analysis of behavioral test data in animal models.

Ligustilide, a novel SIRT1 agonist, alleviates lipopolysaccharide-induced acute lung injury through deacetylation of NICD

Development and progression of sepsis-induced acute lung injury (ALI) involve apoptosis and oxidative stress in lung epithelial cells. Ligustilide (LIG) is one of the main bioactive constituents derived from the Angelica sinensis. As a novel SIRT1 agonist, LIG owns powerful anti-inflammatory and antioxidative properties, exerting remarkable therapeutic effects on cancers, neurological disorders, and diabetes mellitus. However, whether LIG could protect against lipopolysaccharide (LPS)-induced ALI by activating SIRT1 remains unclear. Mice underwent intratracheal LPS injection to mimic sepsis-induced ALI while MLE-12 cells were treated with LPS for 6 h to establish an in vitro ALI model. At the same time, mice or MLE-12 cells were treated with different doses of LIG to access its pharmacological effect. The results demonstrated that LIG pretreatment could improve LPS-induced pulmonary dysfunction and pathological injury, apart from increasing 7-day survival rate. In addition, LIG pretreatment also decreased inflammation, oxidative stress and apoptosis during LPS-induced ALI. Mechanically, LPS stimulation decreased the expression and activity of SIRT1 but increased the expression of Notch1 and NICD. And LIG could also enhance the interaction between SIRT1 and NICD, thus deacetylating NICD. In vitro experiments also unveiled that EX-527, a selective SIRT1 inhibitor, could abolish LIG-elicited protection in LPS-treated MLE-12 cells. And in SIRT1 knockout mice with ALI, LIG pretreatment also lost its effects on inflammation, apoptosis, and oxidative stress during ALI.

Targeting dynamin-related protein-1 as a potential therapeutic approach for mitochondrial dysfunction in Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease that manifests its pathology through synaptic damage, mitochondrial abnormalities, microRNA deregulation, hormonal imbalance, increased astrocytes & microglia, accumulation of amyloid β (Aβ) and phosphorylated Tau in the brains of AD patients. Despite extensive research, the effective treatment of AD is still unknown. Tau hyperphosphorylation and mitochondrial abnormalities are involved in the loss of synapses, defective axonal transport and cognitive decline in patients with AD. Mitochondrial dysfunction is evidenced by enhanced mitochondrial fragmentation, impaired mitochondrial dynamics, mitochondrial biogenesis and defective mitophagy in AD. Hence, targeting mitochondrial proteins might be a promising therapeutic strategy in treating AD. Recently, dynamin-related protein 1 (Drp1), a mitochondrial fission protein, has gained attention due to its interactions with Aβ and hyperphosphorylated Tau, altering mitochondrial morphology, dynamics, and bioenergetics. These interactions affect ATP production in mitochondria. A reduction in Drp1 GTPase activity protects against neurodegeneration in AD models. This article provides a comprehensive overview of Drp1's involvement in oxidative damage, apoptosis, mitophagy, and axonal transport of mitochondria. We also highlighted the interaction of Drp1 with Aβ and Tau, which may contribute to AD progression. In conclusion, targeting Drp1 could be a potential therapeutic approach for preventing AD pathology.

Antitumor Activity of Ligustilide Against Ehrlich Solid Carcinoma in Rats via Inhibition of Proliferation and Activation of Autophagy

Background Cancer is the second-leading cause of death worldwide. According to a 2018 WHO report, 9.6 million deaths occurred globally due to cancer. Ehrlich carcinoma is characterized by rapid proliferation and a short survival time. Ligustilide is a phthalide derivative and is one of the main compounds in Danggui essential oil and Rhizoma Chuanxiong. It has many protective effects, such as anticancer, anti-inflammatory, antioxidant, and neuroprotective effects. Aims We conducted this study to investigate the antitumor activity of ligustilide against Ehrlich solid carcinoma (ESC) in rats by affecting beclin 1, mammalian target of rapamycin (mTOR), B-cell lymphoma 2 (BCL2), and 5' AMP-activated protein kinase (AMPK). Materials and methods Twenty rats were intramuscularly implanted in the thigh of the left hind limb with a 200-µL tumor cell suspension in PBS containing 2 × 10⁶ cells. After eight days of inoculation, 10 rats out of the 20 were treated with oral 20 mg/kg ligustilide daily. At the end of the experiment, samples of muscles with ESC were separated. Sections prepared from the muscle samples with ESC were immunohistochemically stained with anti-Ki67 antibodies. Another part of the muscle samples with ESC was used to assess gene expression and protein levels of beclin 1, mTOR, BCL2, and AMPK. Results  Treatment of carcinoma rats with ligustilide elevated the mean survival time and reduced tumor volume and weight. Moreover, examination of tumor tissue stained with hematoxylin/eosin showed an infiltrative, highly cell-dense mass supported by a small to moderate amount of fibrovascular stroma and intersected with multifocal myofibril necrosis. Treatment with ligustilide ameliorated all these effects in the carcinoma group without affecting the control group. Finally, treatment with ligustilide significantly decreased the expression of beclin 1, mTOR, and AMPK associated with elevated expression of BCL2. Conclusions  Our study aimed to explore the potential chemotherapeutic activity of ligustilide against ESC. We found that ligustilide effectively reduced tumor size and weight, indicating its antineoplastic activity against ESC. We further investigated that ligustilide inhibits cell proliferation by suppressing Ki67 and mTOR and activates autophagy through beclin 1 activation. Moreover, ligustilide inhibits apoptosis by upregulating BCL2. Finally, ligustilide reduced the expression of AMPK, preventing its ability to promote tumor cell growth.

Role of microbial dysbiosis in the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is the leading cause of dementia in the elderly and detected during the advanced stages where the chances of reversal are minimum. The gut-brain axis mediates a bidirectional communication between the gut and brain, which is dependent on bacterial products such as short chain fatty acids (SCFA) and neurotransmitters. Accumulating lines of evidence suggests that AD is associated with significant alteration in the composition of gut microbiota. Furthermore, transfer of gut microbiota from healthy individuals to patients can reshape the gut microbiota structure and thus holds the potential to be exploited for the treatment of various neurodegenerative disease. Moreover, AD-associated gut dysbiosis can be partially reversed by using probiotics, prebiotics, natural compounds and dietary modifications, but need further validations. Reversal of AD associated gut dysbiosis alleviate AD-associated pathological feature and therefore can be explored as a therapeutic approach in the future. The current review article will describe various studies suggesting that AD dysbiosis occurs with AD and highlights the causal role by focussing on the interventions that hold the potential to reverse the gut dysbiosis partially.

Natural essential oils derived from herbal medicines: A promising therapy strategy for treating cognitive impairment

Cognitive impairment (CI), mainly Alzheimer’s disease (AD), continues to increase in prevalence and is emerging as one of the major health problems in society. However, until now, there are no first-line therapeutic agents for the allopathic treatment or reversal of the disease course. Therefore, the development of therapeutic modalities or drugs that are effective, easy to use, and suitable for long-term administration is important for the treatment of CI such as AD. Essential oils (EOs) extracted from natural herbs have a wide range of pharmacological components, low toxicity, and wide sources, In this review, we list the history of using volatile oils against cognitive disorders in several countries, summarize EOs and monomeric components with cognitive improvement effects, and find that they mainly act by attenuating the neurotoxicity of amyloid beta, anti-oxidative stress, modulating the central cholinergic system, and improving microglia-mediated neuroinflammation. And combined with aromatherapy, the unique advantages and potential of natural EOs in the treatment of AD and other disorders were discussed. This review hopes to provide scientific basis and new ideas for the development and application of natural medicine EOs in the treatment of CI.

Stimulation of functional recovery via neurorepair mechanisms by the traditional Japanese Kampo medicine, Ninjin'yoeito, and physical exercise in a rat ischemic stroke model

ETHNOPHARMACOLOGICAL RELEVANCE

Ninjin'yoeito (NYT), a traditional Japanese Kampo medicine consisting of 12 herbs, has been reported to improve cognitive dysfunction, depression, and neurological recovery in patients with neurovascular diseases such as Alzheimer's disease and stroke. Several studies have reported that the NYT components exert neurotrophic, neurogenic, and neuroprotective effects. In addition, exercise enhances neuroprotection and functional recovery after stroke. Rehabilitative exercises and pharmacological agents induce neurophysiological plasticity, leading to functional recovery in stroke patients. These reports indicate that NYT treatment and exercise may promote functional recovery following stroke through their beneficial effects. However, no study has determined the effects of NYT and the possible mechanisms of neurorepair and functional recovery after stroke.

AIM OF THE STUDY

This study aimed to investigate the combined effects of NYT and exercise on neuroprotection and functional recovery and the underlying mechanisms in a rat ischemic stroke model.

MATERIALS AND METHODS

Stroke was induced with 60-min middle cerebral artery occlusion (MCAO) followed by reperfusion in adult male Sprague-Dawley rats. After stroke, the rats were assigned to four groups: ischemia reperfusion (IR), NYT, exercise (Ex), and NYT + Ex. NYT-treated rats were fed a diet containing 1% NYT one day after stroke. Exercise was performed using a motorized treadmill for 5 days a week (8-15 m/min, 20 min/day), starting 3 days after stroke. The NYT treatment and exercise were continued for 4 weeks after the stroke. Infarct volume, neurological deficits, sensorimotor functions, expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase A (TrkA) and B (TrkB), caspase-3 activity, and the p-Akt/Akt ratio were examined by immunohistochemistry and western blotting.

RESULTS

Compared to the IR group, all treated groups indicated reduced infarct volumes. The NYT + Ex group showed significantly improved waking time and beam walking score compared with the IR group. The expression of NGF/TrkA/p-TrkA and BDNF/TrkB was significantly increased in the NYT + Ex group compared with those in the IR group, whereas the number of caspase-3 positive cells around the lesion was significantly lower in the NYT + Ex group than in the IR group. In addition, the ratio of p-Akt/Akt was significantly higher in the NYT + Ex group than in the IR group.

CONCLUSIONS

This study suggests that NYT in combination with exercise provides neuroprotective effects and improves sensorimotor function by stimulating NGF/TrkA and BDNF/TrkB, and by activating the Akt pathway in ischemic stroke of rats. NYT may be an effective adjunctive agent in post-stroke rehabilitation.

Effects of Scrophularia buergeriana Extract (Brainon®) on Aging-Induced Memory Impairment in SAMP8 Mice

Alzheimer's disease (AD) is a worldwide problem. Currently, there are no effective drugs for AD treatment. Scrophularia buergeriana Miquel (SB) is a traditional herbal medicine used in Korea to treat various diseases. Our previous studies have shown that ethanol extract of SB roots (SBE, Brainon^®) exhibits potent anti-amnesic effects in Aβ_1-42- or scopolamine-treated memory impairment mice model and neuroprotective effects in a glutamate-induced SH-SY5Y cell model. In this study, we evaluated the therapeutic effects of Brainon^® and its mechanism of action in senescence-accelerated mouse prone 8 (SAMP8) mice. Brainon^® (30 or 100 mg/kg/day) was orally treated to six-month-old SAMP8 mice for 12 weeks. Results revealed that Brainon^® administration effectually ameliorated cognitive deficits in Y-maze and passive avoidance tests. Following the completion of behavioral testing, western blotting was performed using the cerebral cortex. Results revealed that Brainon^® suppressed Aβ_1-42 accumulation, Tau hyperphosphorylation, oxidative stress, and inflammation and alleviated apoptosis in SAMP8 mice. Brainon^® also promoted synaptic function by downregulating the expression of AChE and upregulating the expression of p-CREB/CREB and BDNF. Furthermore, Brainon^® restored SAMP8-reduced expression of ChAT and -dephosphorylated of ERK and also decreased AChE expression in the hippocampus. Furthermore, Brainon^® alleviated AD progression by promoting mitophagy/autophagy to maintain normal cellular function as a novel finding of this study. Our data suggest that Brainon^® can remarkably improve cognitive deficiency with the potential to be utilized in functional food for improving brain health.

Inhibition of Drp1-dependent mitochondrial fission by natural compounds as a therapeutic strategy for organ injuries

Mitochondria are morphologically dynamic organelles frequently undergoing fission and fusion processes that regulate mitochondrial integrity and bioenergetics. These processes are considered critical for cell survival. The mitochondrial fission process regulates mitochondrial biogenesis and mitophagy. It is associated with apoptosis, while mitochondrial fusion controls the accurate distribution of mitochondrial DNA and metabolic substances across the mitochondria. Excessive mitochondrial fission results in mitochondrial structural changes, dysfunction, and cell damage. Accumulating evidence demonstrates that mitochondrial dynamics affect neurodegenerative and cardiovascular diseases along with several other diseases. Biological molecules regulating the process of mitochondrial fission are potential targets for developing therapeutic agents. Many natural products target the dynamin-related protein 1 (Drp1)-dependent mitochondrial fission pathway, and their inhibitory effects ameliorate mitochondrial fragmentation. In this article, we reviewed the research literature that describes Drp1-dependent inhibition as a mechanism for the protective effects of natural compounds.

Tanshinone IIA ameliorates Aβ transendothelial transportation through SIRT1-mediated endoplasmic reticulum stress

BACKGROUND

The disruption of blood-brain barrier (BBB), predominantly made up by brain microvascular endothelial cells (BMECs), is one of the characteristics of Alzheimer's disease (AD). Thus, improving BMEC function may be beneficial for AD treatment. Tanshinone IIA (Tan IIA) has been proved to ameliorate the cognitive dysfunction of AD. Herein, we explored how Tan IIA affected the function of BMECs in AD.

METHODS

Aβ_1-42-treated brain-derived endothelium cells.3 (bEnd.3 cells) was employed for in vitro experiments. And we performed molecular docking and qPCR to determine the targeting molecule of Tan IIA on Sirtuins family. The APP^swe/PS^dE9 (APP/PS1) mice were applied to perform the in vivo experiments. Following the behavioral tests, protein expression was determined through western blot and immunofluorescence. The activities of oxidative stress-related enzymes were analyzed by biochemically kits. Nissl staining and thioflavin T staining were conducted to reflect the neurodegeneration and Aβ deposition respectively.

RESULTS

Molecular docking and qPCR results showed that Tan IIA mainly acted on Sirtuin1 (SIRT1) in Sirtuins family. The inhibitor of SIRT1 (EX527) was employed to further substantiate that Tan IIA could attenuate SIRT1-mediated endoplasmic reticulum stress (ER stress) in BMECs. Behavioral tests suggested that Tan IIA could improve the cognitive deficits in APP/PS1 mice. Tan IIA administration increased SIRT1 expression and alleviated ER stress in APP/PS1 mice. In addition, LRP1 expression was increased and RAGE expression was decreased after Tan IIA administration in both animals and cells.

CONCLUSION

Tan IIA could promote Aβ transportation by alleviating SIRT1-mediated ER stress in BMECs, which ameliorated cognitive deficits in APP/PS1 mice.

The contribution of mitochondria-associated endoplasmic reticulum membranes (MAMs) dysfunction in Alzheimer's disease and the potential countermeasure

Alzheimer's disease (AD) is the most common neurodegenerative disease. There are many studies targeting extracellular deposits of amyloid β-peptide (Aβ) and intracellular neurofibrillary tangles (NFTs), however, there are no effective treatments to halt the progression. Mitochondria-associated endoplasmic reticulum membranes (MAMs) have long been found to be associated with various pathogenesis hypotheses of AD, such as Aβ deposition, mitochondrial dysfunction, and calcium homeostasis. However, there is a lack of literature summarizing recent advances in the mechanism and treatment studies. Accordingly, this article reviews the latest research involving the roles of MAM structure and tethering proteins in the pathogenesis of AD and summarizes potential strategies targeting MAMs to dissect treatment perspectives for AD.

Medicine-food herb: Angelica sinensis, a potential therapeutic hope for Alzheimer's disease and related complications

Alzheimer's disease (AD) is a progressive neurodegenerative disease, which has brought a huge burden to the world. The current therapeutic approach of one-molecule-one-target strategy fails to address the issues of AD because of multiple pathological features of AD. Traditionally, the herb of Angelica sinensis (AS) comes from the root of an umbrella plant Angelica sinensis (Oliv.) Diels. As a typical medicine-food herb, studies have shown that AS can alleviate AD and AD-complications by multiple targets through the various foundations of pharmaceutical material and dietary supply basis. Therefore, this review summarizes the pharmacological effects of AS for the treatment of AD and AD-complications for the first time. AS contains many effective components, such as ligustilide, z-ligustilide, n-butylidenephthalide, α-pinene, p-cymene, myrcene, ferulic acid, vanillic acid and coniferyl ferulate. It is found that AS, AS-active compounds and AS-compound recipes mainly treat AD through neuroprotective, anti-inflammation, and anti-oxidant effects, improving mitochondrial dysfunction, anti-neuronal apoptosis, regulating autophagy, regulating intestinal flora and enhancing the central cholinergic system, which shows the multi-component and multi-target effect of AS. The role of dietary supplement components in AS for AD intervention is summarized, including vitamin B₁₂, folic acid, arginine, and oleic acid, which can improve the symptoms of AD. Besides, this review focuses on the safety and toxicity evaluation of AS, which provides a basis for its application. This review will provide further support for the research on AD and the application of medicine-food herb AS in a healthy lifestyle in the future.

Ligustilide Improves Cognitive Impairment via Regulating the SIRT1/IRE1α/XBP1s/CHOP Pathway in Vascular Dementia Rats

Vascular dementia (VaD), the second cause of dementia, is caused by chronic cerebral hypoperfusion, producing progressive damage to cerebral cortex, hippocampus, and white matter. Ligustilide (LIG), one of the main active ingredients of Angelica sinensis, exerts the neuroprotective effect on neurodegenerative diseases. However, the mechanism remains unclear. An in vivo model of bilateral common carotid artery occlusion and in vitro model of oxygen glucose deprivation (OGD) were employed in this study. LIG (20 or 40 mg/kg/day) was intragastrically administered to the VaD rats for four weeks. The results of the Morris water maze test demonstrated that LIG effectively ameliorated learning and memory deficiency in VaD rats. LIG obviously relieved neuronal oxidative stress damage by increasing the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) and decreasing the level of malondialdehyde (MDA) in VaD rats. Nissl staining showed that LIG increased the number of the Nissl body in VaD rats. After LIG administration, the apoptotic-related protein, Bax, was decreased and Bcl-2 was increased in the hippocampus of VaD rats. Moreover, the expressions of sirtuin 1 (SIRT1) and protein disulfide isomerase (PDI) were decreased, binding immunoglobulin protein (BIP) and phospho-inositol-requiring enzyme-1α (P-IRE1α), X-box binding protein 1 (XBP1s), and C/EBP-homologous protein (CHOP) were increased in VaD rats. After LIG treatment, these changes were reversed. The immunofluorescence results further showed that LIG upregulated the expression of SIRT1 and downregulated the expression of P-IRE1α in VaD rats. In addition, in vitro experiment showed that EX-527 (SIRT1 inhibitor) partly abolished the inhibitory effect of LIG on the IRE1α/XBP1s/CHOP pathway. In conclusion, these studies indicated that LIG could improve cognitive impairment by regulating the SIRT1/IRE1α/XBP1s/CHOP pathway in VaD rats.

Amaryllidaceae, Lycopodiaceae Alkaloids and Coumarins—A Comparative Assessment of Safety and Pharmacological Activity

The study aimed to evaluate the safety and pharmacological activity Amaryllidaceae, Lycopodiaceae alkaloids and coumarins obtained from Narcissus triandrus L., Lycopodium clavatum L., Lycopodium annotinum L., Huperzia selago L. and Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav. In the in vivo studies. The influence of the tested compounds on the central nervous system of rats was assessed in behavioral tests (locomotor activity, Y-maze, passive avoidance). In order to investigate the mechanisms of action, biochemical determinations were performed (AChE activity, BChE activity, IL-1β, IL-6 concentration). In order to assess safety, the concentrations of AST, ALT, GGT and urea and creatinine were determined. The results of the conducted studies indicate a high safety profile of the tested compounds. Behavioral tests showed that they significantly improved rodent memory in a passive avoidance test. The results of biochemical studies showed that by reducing the activity of AChE and BChE and lowering the concentration of IL-1β and IL-6, the coumarin-rich Angelica dahurica extract shows the most promising potential for future therapeutic AD strategies.

A Review of Traditional Chinese Medicine, Buyang Huanwu Decoction for the Treatment of Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) is often referred to as “collaterals disease” in traditional Chinese medicine (TCM), and commonly includes ischemic and hemorrhagic CSVD. TCM has a long history of treating CSVD and has demonstrated unique efficacy. Buyang Huanwu Decoction (BHD) is a classical TCM formula that has been used for the prevention and treatment of stroke for hundreds of years. BHD exerts its therapeutic effects on CSVD through a variety of mechanisms. In this review, the clinical and animal studies on BHD and CSVD were systematically introduced. In addition, the pharmacological mechanisms, active components, and clinical applications of BHD in the treatment of CSVD were reviewed. We believe that an in-depth understanding of BHD, its pharmacological mechanism, disease-drug interaction, and other aspects will help in laying the foundation for its development as a new therapeutic strategy for the treatment of CSVD.

Ligustilide ameliorates cognitive impairment via AMPK/SIRT1 pathway in vascular dementia rat

Vascular dementia (VaD) is the second cause of dementia after Alzheimer's disease. Ligustilide (LIG) is one of the main active ingredients of traditional Chinese medicines, such as Angelica. Studies have reported that LIG could protect against VaD. However, the mechanism is still confused. In this study, we employed a bilateral common carotid artery occlusion rat model to study. LIG (20 or 40 mg/kg/day) and Nimodipine (20 mg/kg) were orally administered to the VaD rats for four weeks. Morris water maze test showed that LIG effectively ameliorated learning and memory impairment in VaD rats. LIG obviously reduced neuronal oxidative stress damage and the level of homocysteine in the brain of VaD rats. Western blot results showed that pro-apoptotic protein Bax and cleaved caspase 3 increased and anti-apoptotic protein Bcl-2 decreased in the hippocampi of VaD rats. But after LIG treatment, these changes were reversed. Moreover, Nissl staining result showed that LIG could reduce neuronal degeneration in VaD rats. Furthermore, LIG enhanced the expressions of P-AMPK and Sirtuin1(SIRT1) in VaD rats. In conclusion, these studies indicated that LIG could ameliorate cognitive impairment in VaD rats, which might be related to AMPK/SIRT1 pathway activation.

The neuroprotective effects of intermittent fasting on brain aging and neurodegenerative diseases via regulating mitochondrial function

Intermittent fasting (IF) has been studied for its effects on lifespan and the prevention or delay of age-related diseases upon the regulation of metabolic pathways. Mitochondria participate in key metabolic pathways and play important roles in maintaining intracellular signaling networks that modulate various cellular functions. Mitochondrial dysfunction has been described as an early feature of brain aging and neurodegeneration. Although IF has been shown to prevent brain aging and neurodegeneration, the mechanism is still unclear. This review focuses on the mechanisms by which IF improves mitochondrial function, which plays a central role in brain aging and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. The cellular and molecular mechanisms of IF in brain aging and neurodegeneration involve activation of adaptive cellular stress responses and signaling- and transcriptional pathways, thereby enhancing mitochondrial function, by promoting energy metabolism and reducing oxidant production.

Neurotherapy of Yi-Gan-San, a Traditional Herbal Medicine, in an Alzheimer's Disease Model of Drosophila melanogaster by Alleviating Aβ42 Expression

Alzheimer's disease (AD), a main cause of dementia, is the most common neurodegenerative disease that is related to the abnormal accumulation of amyloid β (Aβ) proteins. Yi-Gan-San (YGS), a traditional herbal medicine, has been used for the management of neurodegenerative disorders and for the treatment of neurosis, insomnia and dementia. The aim of this study was to examine antioxidant capacity and cytotoxicity of YGS treatment by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in vitro. We explored neuroprotective effects of YGS treatment in alleviating Aβ neurotoxicity of Drosophila melanogaster in vivo by comparing survival rate, climbing index, and Aβ expressions through retinal green fluorescent protein (GFP) expression, highly sensitive immunomagnetic reduction (IMR) and Western blotting assays. In the in vitro study, our results showed that scavenging activities of free radical and SH-SY5Y nerve cell viability were increased significantly (p < 0.01-0.05). In the in vivo study, Aβ₄₂-expressing flies (Aβ₄₂-GFP flies) and their WT flies (mCD8-GFP flies) were used as an animal model to examine the neurotherapeutic effects of YGS treatment. Our results showed that, in comparison with those Aβ₄₂ flies under sham treatments, Aβ₄₂ flies under YGS treatments showed a greater survival rate, better climbing speed, and lower Aβ₄₂ aggregation in Drosophila brain tissue (p < 0.01). Our findings suggest that YGS should have a beneficial alternative therapy for AD and dementia via alleviating Aβ neurotoxicity in the brain tissue.

Neuroprotective Effect of Danggui Shaoyao San via the Mitophagy-Apoptosis Pathway in a Rat Model of Alzheimer's Disease

Alzheimer's disease (AD) is a serious neurodegenerative disease. While the main pathological characteristic of AD is widely believed to be the accumulation of amyloid-beta (Aβ) in neurons around neurofibrillary plaques, the molecular mechanism of pathological changes is not clear. Traditional Chinese medicine offers many treatments for AD. Among these, Danggui Shaoyao San (DSS) is a classic prescription. In this study, an AD model was established by injecting Aβ 1-42 into the brains of rats, which were then treated with different concentrations of Danggui Shaoyao San (sham operation; model; and Danggui Shaoyao San high-dose, medium-dose, and low-dose intervention groups). The Morris water maze test was used to assess the learning and memory abilities of the animals in each group. Nissl staining was used to detect neurons. Mitophagy was evaluated by transmission electron microscopy and immunofluorescence colocalization. Apoptosis was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The expression levels of autophagy- and apoptosis-related proteins were measured by western blot. Compared to the model group, the groups of AD rats administered medium and high doses of Danggui Shaoyao San showed significantly increased learning and memory abilities (P < 0.05), as well as significantly increased autophagosomes in the hippocampus. Moreover, the expression of PTEN-induced kinase 1 (PINK1), Parkin, and microtubule-associated protein light chain 3 (LC3-I/LC3-II) was increased, while that of p62 was significantly decreased (P < 0.05). The neuronal apoptosis rate was also significantly decreased, the Bcl-2/Bax ratio was significantly increased, and the cleaved caspase-3 protein expression was significantly decreased (P < 0.05). Therefore, Danggui Shaoyao San inhibited neuronal apoptosis in AD rats via a mechanism that may be related to the activation of the PINK1-Parkin-mediated mitophagy signaling pathway.

DL0410 ameliorates cognitive disorder in SAMP8 mice by promoting mitochondrial dynamics and the NMDAR-CREB-BDNF pathway

Alzheimer's disease (AD) is a worldwide problem and there are no effective drugs for AD treatment. Previous studies show that DL0410 is a multi-target, anti-AD agent. In this study, we investigated the therapeutic effect of DL0410 and its action mechanism in SAMP8 mice. DL0410 (1-10 mg·kg^-1·d^-1) was orally administered to 8-month-old SAMP mice (SAMP8) for 8 weeks. We showed that DL0410 administration effectively ameliorated the cognitive deficits in the Morris water maze test, novel object recognition test, and nest building test. We revealed that DL0410 dose-dependently increased the expression levels of the mitochondrial proteins (PGC-1α, Mitofusin 2, OPA1, and Drp1), and subsequently ameliorated the processes of mitochondrial biosynthesis, fusion, and fission in the cortex and hippocampus of SAMP8 mice. Furthermore, DL0410 administration promoted the expression of synaptic proteins (synaptophysin and PSD95) in the brain of SAMP8 mice, and upregulated the protein phosphorylation in NMDAR-CAMKII/CAMKIV-CREB pathway responsible for the synaptic plasticity. DL0410 administration dose-dependently increased the expression of BDNF and TrkB, and the neurotrophic effect was mediated via the ERK1/2 and PI3K-AKT-GSK-3β pathways. DL0410 administration upregulated Bcl-2, increased the Bcl-2/Bax ratio and the level of caspase 3 and PARP-1, alleviating neuronal apoptosis. We proposed that the NMDAR-CREB-BDNF pathway might establish a positive feedback loop between synaptic plasticity and neurotrophy, with CREB at the center. In summary, DL0410 promotes synaptic function and neuronal survival, thus ameliorating cognitive deficits in SAMP8 mice via improved mitochondrial dynamics and increased activity of the NMDAR-CREB-BDNF pathway. DL0410 is a promising candidate to treat aging-related AD, and deserves more research and development in future.

Differential role of melatonin in healthy brain aging: a systematic review and meta-analysis of the SAMP8 model

The relationship between oxidative stress (OS) and cellular senescence (CS) is an important research topic because of the rapidly aging global population. Melatonin (MT) is associated with aging and plays a pivotal role in redox homeostasis, but its role in maintaining physiological stability in the brain (especially in OS-induced senescence) remains elusive. Here, we systematically reviewed the differential role of MT on OS-induced senescence in the SAMP8 mouse model. Major electronic databases were searched for relevant studies. Pooled mean differences (MDs)/standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated to estimate the effect size. Overall, 10 studies met the inclusion criteria. MT treatment was associated with the reduction of lipid peroxidation (SMD = -2.00, 95% CI [-2.91, -1.10]; p < 0.0001) and carbonylated protein (MD = -5.74, 95% CI [-11.03, -0.44]; p = 0.03), and with enhancement of the reduced-glutathione/oxidized-glutathione ratio (MD = 1.12, 95% CI [0.77, 1.47]; p < 0.00001). No differences were found in catalase and superoxide dismutase activities between MT-treated and vehicle-treated groups. Furthermore, nuclear-factor-κB, cyclin-dependent kinase-5, and p53 were regulated by MT administration. MT may improve physiological stability during aging by regulating interactions in brain senescence, but acts differentially on the antioxidant system.

NaoXinTong Capsule ameliorates memory deficit in APP/PS1 mice by regulating inflammatory cytokines

Alzheimer's disease (AD) is the most common neurodegenerative disease in aging population. Neuroinflammation, hyperphosphorylated Tau (p-Tau) and the imbalance between production and clearance of β-amyloid peptide (Aβ) are the major causes for AD development. NaoXinTong Capsule (NXT), a traditional Chinese medicine, is wildly used for treatment of cardiovascular and cerebrovascular diseases. Hence, we used the double transgenic mice expressing chimeric human amyloid precursor protein and mutant human presenilin 1 (APP/PS1) and HT-22 cells to determine the neuroprotective effects of NXT in AD development and the involved mechanisms. The 3-month-old APP/PS1 mice were randomly divided into 3 groups and received following treatment: Control group, mice were fed normal chow; NXT groups, mice were fed normal chow containing NXT at a normal and a high dose, respectively. While the age-matched C57BL/6J mice fed normal chow were used as the normal control. The NXT treatment was lasted for 5 months. We found that NXT treatment improved spatial memory impairment and cognitive decline in APP/PS1 mice by decreasing p-Tau levels and Aβ accumulation in the brain. Mechanistically, we observed that NXT inhibited neuron atrophy and apoptosis by downregulating inflammatory cytokines, interleukin 1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α), and inflammation mediators, nuclear factor κB (NF-κB) and toll-like receptor 4 (TLR4) in the brain. Consistently, NXT blocked l-glutamic acid-induced reactive oxygen species production, inflammation and apoptosis in HT-22 cells partially by inhibiting TLR4/NF-κB/IL-1β signaling pathway. Our study demonstrates that NXT ameliorates AD by reducing p-Tau, Aβ accumulation, inflammation and neuron apoptosis via regulation of TLR4-mediated inflammatory system. It also suggests the potential application of NXT for AD treatment.

Common Protective Strategies in Neurodegenerative Disease: Focusing on Risk Factors to Target the Cellular Redox System

Neurodegenerative disease is an umbrella term for different conditions which primarily affect the neurons in the human brain. In the last century, significant research has been focused on mechanisms and risk factors relevant to the multifaceted etiopathogenesis of neurodegenerative diseases. Currently, neurodegenerative diseases are incurable, and the treatments available only control the symptoms or delay the progression of the disease. This review is aimed at characterizing the complex network of molecular mechanisms underpinning acute and chronic neurodegeneration, focusing on the disturbance in redox homeostasis, as a common mechanism behind five pivotal risk factors: aging, oxidative stress, inflammation, glycation, and vascular injury. Considering the complex multifactorial nature of neurodegenerative diseases, a preventive strategy able to simultaneously target multiple risk factors and disease mechanisms at an early stage is most likely to be effective to slow/halt the progression of neurodegenerative diseases.

Ligustilide alleviates the insulin resistance, lipid accumulation, and pathological injury with elevated phosphorylated AMPK level in rats with diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) is one of the major risk factors of disability and death worldwide. Despite of the protective role of ligustilide (LIG) in many cell types, we aimed to investigate whether LIG could be a potential to treat DM.

METHODS

Sprague Dawley rats were randomly assigned to five groups. Rats except control were raised on a high-fat diet (HFD). Streptozotocin was intraperitoneally injected into HFD-fed rats to construct DM model. Rats in the LIG intervention groups received intraperitoneal injection of LIG (10, 20, and 40 mg/kg) post-induction of DM. Blood glucose, plasma insulin (p-insulin), adiponectin, HbA1C%, obesity index, HOMA-IR, and biochemical parameters were estimated. Histopathological analysis and apoptosis in liver and kidney, along with proliferation and apoptosis of islet β-cells, were analyzed. Expression of CPT-1 and ACC, and phosphorylation of Nrf2 and AMPKα1, were finally assessed.

RESULTS

DM-induced alterations were all relived by LIG intervention. In brief, obesity index, glucose level, P-insulin content, HbA1C, and HOMA-IR were lowered while adiponectin level was elevated. Meanwhile, levels of TC, TG, ALT, and AST were decreased in the LIG intervention groups, along with up-regulated CPT-1 level and down-regulated ACC level. Pathological changes in liver and kidney tissues were alleviated, and apoptotic cells were reduced by LIG treatment. For islet β-cells, LIG up-regulated Ki67 and c-Myc expression, and mitigated ratios of Bax/Bcl-2 and cleaved cas3(9)/cas3(9). Finally, LIG could promote phosphorylation of Nrf2 and AMPKα1.

CONCLUSIONS

LIG alleviated the insulin resistance, lipid accumulation, and pathological injury with the activation of AMPK pathway in DM rats.

Effects of Co-Administration of Icariin and Panax notoginseng Saponins on Intestinal Microbiota and Hippocampal Protein Expression in a Mouse Model of Alzheimer's Disease

OBJECTIVE

We investigated the effect of icariin (ICA) combined with Panax notoginseng saponins (PNS) on intestinal microbiota and hippocampal protein expression in amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice, a model of Alzheimer's disease (AD).

METHODS

Transgenic mice were treated with icariin and PNS. The Morris water maze (MWM) was used to assess spatial memory, and the gut microbiota and differential protein expression in the hippocampus were investigated using high-throughput screening techniques. Differential protein expression was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting.

RESULTS

The MWM results showed that the mice treated with the medium dose of ICA+PNS spent significantly more time in the target quadrant compared with the AD group. Bacterial diversity was the lowest in the AD group, with significantly greater diversity in the ICA + PNS treatment group. Three proteins were selected for proteomic analysis, and qRT-PCR and Western blot were used to detect the expression of 2'-5'-oligoadenylate synthetase ubiquitin like 1 (Oasl1), trichoplein keratin filament-binding protein (TCHP), and tumor necrosis factor receptor associated 3-interacting protein 1 (MIPT3). Compared with control mice, MIPT3 expression was increased and Oasl1 and TCHP were reduced in the AD group. These abnormal protein expressions tended to normalization after treatment with medium dose of ICA and PNS.

CONCLUSION

Treatment with ICA and PNS ameliorated memory impairment in an AD mouse model. The mechanisms may be related to modulation of the intestinal microbiota and expression of Oasl1, TCHP, and MIPT3.