Protective effects of salidroside on hydrogen peroxide-induced apoptosis in SH-SY5Y human neuroblastoma cells

Salidroside: An Overview of Its Promising Potential and Diverse Applications

Salidroside, a phenolic compound isolated from various Rhodiola plants, is the principal active constituent of Traditional Chinese Medicine known for its adaptogenic properties. Due to the challenging environment of Rhodiola species, such as high altitude, high radiation, drought, and hypoxia, the source of salidroside is scarce. However, numerous studies have shown that salidroside has a range of biological activities, including cardiovascular and central nervous system activity, and anti-hypoxia, anti-inflammatory, and anti-aging activities. Although previous studies have partially summarized the pharmacological effects of salidroside, the overall pharmacological effects have not been analyzed. Hence, this review will systematically summarize the isolation, purification, synthesis, derivatization, pharmacological activity, pharmacokinetics, clinical application, and safety of salidroside. It is expected to provide new insights for the further research and pharmaceutical development of salidroside.

Network Pharmacology, Molecular Docking, and In Vitro Insights into the Potential of Mitragyna speciosa for Alzheimer's Disease

Mitragyna speciosa Korth. Havil (MS) has a traditional use in relieving pain, managing hypertension, treating cough, and diarrhea, and as a morphine substitute in addiction recovery. Its potential in addressing Alzheimer's disease (AD), a neurodegenerative condition with no effective treatments, is under investigation. This study aims to explore MS mechanisms in treating AD through network pharmacology, molecular docking, and in vitro studies. Using network pharmacology, we identified 19 MS components that may affect 60 AD-related targets. The compound-target network highlighted significant interactions among 60 nodes and 470 edges, with an average node degree of 15.7. The KEGG enrichment analysis revealed Alzheimer's disease (hsa05010) as a relevant pathway. We connected 20 targets to tau and β-amyloid proteins through gene expression data from the AlzData database. Docking studies demonstrated high binding affinities of MS compounds like acetylursolic acid, beta-sitosterol, isomitraphylline, and speciophylline to AD-related proteins, such as AKT1, GSK3B, NFκB1, and BACE1. In vitro studies showed that ethanolic (EE), distilled water (DWE), and pressurized hot water (PHWE) extracts of MS-treated 100 μM H2O2-induced SH-SY5Y cells significantly reduced oxidative damage. This research underscores the multi-component, multi-target, and multi-pathway effects of MS on AD, providing insights for future research and potential clinical applications.

Salidroside Pre-Treatment Inhibits Hypertensive Renal Injury and Fibrosis Through Inhibiting Wnt/β-Catenin Pathway

Objectives

This study aimed to explore the protective effects and underlying mechanisms of salidroside (SAL) in angiotensin II (Ang II)-induced hypertensive renal injury and fibrosis, using in vivo and in vitro models.

Methods

In this study, we generated Ang II-induced hypertensive renal injury and fibrosis in mice and the recombinant interferon-gamma (IFN-γ)-stimulated murine podocyte clone 5 (MPC5) model in vitro. Histological and oxidative stress analyses were performed to evaluate the renal injury.

Results

SAL pre-treatment reduced systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), and attenuated serum creatinine (Scr), blood urea nitrogen (BUN), and serum cystatin C (Cys-C) levels in Ang II-infused mice (all, P < 0.001). SAL reduced renal fibrosis and related molecules expression, including Collagen I, Collagen III, and α-smooth muscle actin (α-SMA) (all, P < 0.001). SAL decreased the content of malondialdehyde (MDA) while increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in Ang II-treated mice (all, P < 0.001). In addition, SAL pre-treatment inhibited AT1R, Wnt1, Wnt3a, and β-catenin expressions (all, P < 0.001), both in vivo and in vitro.

Conclusion

Our experimental data demonstrate that SAL pre-treatment protects against Ang II-induced hypertensive renal injury and fibrosis by suppressing the Wnt/β-catenin pathway in vivo and in vitro.

Multimodal modulation of hepatic ischemia/reperfusion-induced injury by phytochemical agents: A mechanistic evaluation of hepatoprotective potential and safety profiles

BACKGROUND

Hepatic ischemia-reperfusion (I/R) injury is a clinically fundamental phenomenon that occurs through liver resection surgery, trauma, shock, and transplantation.

AIMS OF THE REVIEW

This review article affords an expanded and comprehensive overview of various natural herbal ingredients that have demonstrated hepatoprotective effects against I/R injury through preclinical studies in animal models.

MATERIALS AND METHODS

For the objective of this investigation, an extensive examination was carried out utilizing diverse scientific databases involving PubMed, Google Scholar, Science Direct, Egyptian Knowledge Bank (EKB), and Research Gate. The investigation was conducted based on specific identifiable terms, such as hepatic ischemia/reperfusion injury, liver resection and transplantation, cytokines, inflammation, NF-kB, interleukins, herbs, plants, natural ingredients, phenolic extract, and aqueous extract.

RESULTS

Bioactive ingredients derived from ginseng, curcumin, resveratrol, epigallocatechin gallate, quercetin, lycopene, punicalagin, crocin, celastrol, andrographolide, silymarin, and others and their effects on hepatic IRI were discussed. The specific mechanisms of action, signaling pathways, and clinical relevance for attenuation of liver enzymes, cytokine production, immune cell infiltration, oxidative damage, and cell death signaling in rodent studies are analyzed in depth. Their complex molecular actions involve modulation of pathways like TLR4, NF-κB, Nrf2, Bcl-2 family proteins, and others.

CONCLUSION

The natural ingredients have promising values in the protection and treatment of various chronic aggressive clinical conditions, and that need to be evaluated on humans by clinical studies.

Exploring the synergistic potential of pomegranate fermented juice compounds against oxidative stress-induced neurotoxicity through computational docking and experimental analysis in human neuroblastoma cells

This study explored the neuroprotective potential of fermented pomegranate (PG-F) against hydrogen peroxide (H2O2)-induced neurotoxicity in human neuroblastoma SH-SY5Y cells and elucidated the underlying molecular mechanisms. The fermentation process, involving probiotics, transforms the hydrolyzable tannins in pomegranate juice into ellagic acid (EA) and gallic acid (GA), which are believed to contribute to its health benefits. Molecular docking simulations confirmed the stable interactions between EA, GA, and proteins associated with the antioxidant and anti-apoptotic pathways. PG-F significantly enhanced the viability of H2O2-treated cells, as evidenced by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, cell morphology observations, and Hoechst 33342 staining. PG-F mitigated the H2O2-induced intracellular reactive oxygen species (ROS) levels, restored mitochondrial membrane potential, and upregulated antioxidant gene expression. The PG-F treatment also attenuated the H2O2-induced imbalance in the Bax/Bcl-2 ratio and reduced the cleaved caspase-3, caspase-7, and caspase-9 levels, suppressing the apoptotic pathways. Further insights showed that PG-F inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) and facilitated the nuclear translocation of nuclear factor-erythroid 2-related factor (Nrf2), highlighting its role in modulating the key signaling pathways. A combined treatment with equivalent concentrations of EA and GA, as found in PG-F, induced remarkable cellular protection. Drug combination analysis using the Chou-Talalay method revealed a synergistic effect between EA and GA, emphasizing their combined efficacy. In conclusion, PG-F has significant neuroprotective effects against H2O2-induced neurotoxicity by modulating the antioxidant and anti-apoptotic pathways. The synergistic action of EA and GA suggests the therapeutic potential of PG-F in alleviating oxidative stress-associated neurodegenerative diseases.

Prevention of colistin-induced neurotoxicity: a narrative review of preclinical data

Polymyxin E or colistin is an effective antibiotic against MDR Gram-negative bacteria. Due to unwanted side effects, the use of this antibiotic has been limited for a long time, but in recent years, the widespread of MDR Gram-negative bacteria infections has led to its reintroduction. Neurotoxicity and nephrotoxicity are the significant dose-limiting adverse effects of colistin. Several agents with anti-inflammatory and antioxidant properties have been used for the prevention of colistin-induced neurotoxicity. This study aims to review the preclinical studies in this field to prepare guidance for future human studies. The data was achieved by searching PubMed, Scopus, and Google Scholar databases. All eligible pre-clinical studies performed on neuroprotective agents against colistin-induced neurotoxicity, which were published up to September 2023, were included. Finally, 16 studies (ten in vitro and eight in vivo) are reviewed. Apoptosis (in 13 studies), inflammatory (in four studies), and oxidative stress (in 14 studies) pathways are the most commonly reported pathways involved in colistin-induced neurotoxicity. The assessed compounds include non-herbal (e.g., ascorbic acid, rapamycin, and minocycline) and herbal (e.g., curcumin, rutin, baicalein, salidroside, and ginsenoside) agents. Besides these compounds, some other measures like transplantation of mitochondria and the use of nerve growth factor and mesenchymal stem cells could be motivating subjects for future research. Based on the data from experimental (in vitro and animal) studies, a combination of colistin with neuroprotective agents could prevent or decrease colistin-induced neurotoxicity. However, well-designed randomized clinical trials and human studies are essential for demonstrating efficacy.

Protective effect of Ganoderma lucidum-fermented crop extracts against hydrogen peroxide- or β-amyloid-induced damage in human neuronal SH-SY5Y cells

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the accumulation of stacked β-amyloid peptides in the brain and associated with the generation of oxidative stress. So far, there is no cure for AD or a way to stop its progression. Although the neuroprotective effects of Ganoderma lucidum aqueous extract and G. lucidum-derived triterpenoids and polysaccharides have been reported, the influence of G. lucidum-fermented crops on AD still lacks clarity.

METHODS

This study aimed to investigate the protective effect of G. lucidum-fermented crop extracts against hydrogen peroxide- or β-amyloid peptide (Aβ25-35)-induced damage in human neuroblastoma SH-SY5Y cells.

RESULTS

Various extracts of G. lucidum-fermented crops, including extract A: 10% ethanol extraction using microwave, extract B: 70˚C water extraction, and extract C: 100˚C water extraction followed by ethanol precipitation, were prepared and analyzed. Extract B had the highest triterpenoid content. Extract C had the highest total glucan content, while extract A had the highest gamma-aminobutyric acid (GABA) content. The median inhibitory concentration (IC50, mg/g) for DPPH and ABTS scavenging activity of the fermented crop extracts was significantly lower than that of the unfermented extract. Pretreatment with these extracts significantly increased the cell viability of SH-SY5Y cells damaged by H2O2 or Aβ25-35, possibly by reducing cellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels and increasing superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. Moreover, extract B markedly alleviated the activity of acetylcholinesterase (AChE), which is crucial in the pathogenesis of AD.

CONCLUSION

These results clearly confirmed the effects of G. lucidum-fermented crop extracts on preventing against H2O2- or Aβ25-35-induced neuronal cell death and inhibiting AChE activity, revealing their potential in management of AD.

The mechanism of UNC-51-like kinase 1 and the applications of small molecule modulators in cancer treatment

Autophagy is a process of self-renewal in cells, which not only provides the necessary nutrients for cells, but also clears necrotic organelles. Autophagy disorders are closely related to diseases such as cancer. UNC-51-like kinase 1 (ULK1) is a serine/threonine protein kinase that plays a crucial role in receiving input from energy and nutrient sensors, activating autophagy to maintain cellular homeostasis under stressful conditions. In recent years, targeting ULK1 has become a highly promising strategy for cancer treatment. This review introduces the regulatory mechanism of ULK1 in autophagy through the AMPK/mTOR/ULK1 pathway and reviews the research progress of ULK1 activators and inhibitors and their applications in cancer treatment. In addition, we analyze the binding modes between ULK1 and modulators through virtual molecular docking, which will provide a reliable basis and theoretical guidance for the design and development of new therapeutic drugs targeting ULK1.

Effect of salidroside on neuroprotection and psychiatric sequelae during the COVID-19 pandemic: A review

The coronavirus disease 2019 (COVID-19) pandemic has affected the mental health of individuals worldwide, and the risk of psychiatric sequelae and consequent mental disorders has increased among the general population, health care workers and patients with COVID-19. Achieving effective and widespread prevention of pandemic-related psychiatric sequelae to protect the mental health of the global population is a serious challenge. Salidroside, as a natural agent, has substantial pharmacological activity and health effects, exerts obvious neuroprotective effects, and may be effective in preventing and treating psychiatric sequelae and mental disorders resulting from stress stemming from the COVID-19 pandemic. Herein, we systematically summarise, analyse and discuss the therapeutic effects of salidroside in the prevention and treatment of psychiatric sequelae as well as its roles in preventing the progression of mental disorders, and fully clarify the potential of salidroside as a widely applicable agent for preventing mental disorders caused by stress; the mechanisms underlying the potential protective effects of salidroside are involved in the regulation of the oxidative stress, neuroinflammation, neural regeneration and cell apoptosis in the brain, the network homeostasis of neurotransmission, HPA axis and cholinergic system, and the improvement of synaptic plasticity. Notably, this review innovatively proposes that salidroside is a potential agent for treating stress-induced health issues during the COVID-19 pandemic and provides scientific evidence and a theoretical basis for the use of natural products to combat the current mental health crisis.

Neuroprotective Mechanisms of Salidroside in Alzheimer's Disease: A Systematic Review and Meta-analysis of Preclinical Studies

Alzheimer's disease (AD) is a neurodegenerative disease of the central nervous system that occurs in old age and pre-aging, characterized by progressive cognitive dysfunction and behavioral impairment. Salidroside (Sal) is a phenylpropanoid mainly isolated from Rhodiola species with various pharmacological effects. However, the exact anti-AD mechanism of Sal has not been clearly elucidated. This meta-analysis aims to investigate the possible mechanisms by which Sal exerts its anti-AD effects by evaluating behavioral indicators and biochemical characteristics. A total of 20 studies were included, and the results showed that the Sal treatment significantly improved behavior abnormalities in AD animal models. With regard to neurobiochemical indicators, Sal treatment could effectively increase the antioxidant enzyme superoxide dismutase, decrease the oxidative stress indicator malondialdehyde, and decrease the inflammatory indicators interleukin 1β, interleukin 6, and tumor necrosis factor α. Sal treatment was effective in reducing neuropathological indicators, such as amyloid-β levels and the number of apoptotic cells. When the relevant literature on the treatment of rodent AD models is combined with Sal, the therapeutic potential of Sal through multiple mechanisms was confirmed. However, further confirmation by higher quality studies, larger sample sizes, and more comprehensive outcome evaluations in clinical trials is needed in the future.

Botanical Mixture Containing Nitric Oxide Metabolite Enhances Neural Plasticity to Improve Cognitive Impairment in a Vascular Dementia Rat Model

Vascular dementia (VD), caused by impaired cerebral blood flow, is the most common form of dementia after Alzheimer's disease (AD) in the elderly and is characterized by severe neuronal damage and cognitive decline. Nitric oxide (NO) is an important determinant of vascular homeostasis, and its deficiency is associated with the progression of VD. In this study, we investigated the role of nitrite ion, a NO metabolite in a botanical mixture (BM) of fermented garlic, fermented Scutellaria baicalensis, and Rhodiola rosea on neuron loss and cognitive impairment using a VD rat model. The BM containing the NO metabolite alleviated cognitive deficits and enhanced neural plasticity, as reflected by an increase in long-term potentiation. The BM also alleviated neuron apoptosis, decreased GFAP expression, and oxidative stress, and increased parvalbumin and brain-derived neurotrophic factor (BDNF) levels. These results indicate that BM exerts neuroprotective effects and alleviates cognitive dysfunction while enhancing neuroplasticity, and thus has therapeutic potential against VD.

Rhodiola rosea and Salidroside commonly induce hormesis, with particular focus on longevity and neuroprotection

The biological effects of Rhodiola rosea extracts and one of its major constituents, Salidroside, were evaluated for their capacity to induce hormesis/hormetic effects. The findings indicate that the Rhodiola rosea extracts and Salidroside commonly induce hormetic dose responses within a broad range of biological models, cell types and across a broad range of endpoints, with particular emphasis on longevity and neuroprotective endpoints. This paper represents the first integrative documentation and assessment of Rhodiola rosea extracts and Salidroside induction of hormetic effects. These findings have important biomedical applications and should have an important impact with respect to critical study design, dose selection and other experimental features.

Centella asiatica (L.) Urban. Attenuates Cell Damage in Hydrogen Peroxide-Induced Oxidative Stress in Transgenic Murine Embryonic Stem Cell Line-Derived Neural-Like Cells: A Preliminary Study for Potential Treatment of Alzheimer's Disease

BACKGROUND

Centella asiatica (L.) (C. asiatica) is commonly known in South East and South East Asia communities for its nutritional and medicinal benefits. Besides being traditionally used to enhance memory and accelerate wound healing, its phytochemicals have been extensively documented for their neuroprotective, neuroregenerative, and antioxidant properties.

OBJECTIVE

The present study aims to investigate the effects of a standardized raw extract of C. asiatica (RECA) on hydrogen peroxide (H2O2)-induced oxidative stress and apoptotic death in neural-like cells derived from mouse embryonic stem (ES) cell line.

METHODS

A transgenic mouse ES cell (46C) was differentiated into neural-like cells using 4-/4+ protocol with addition of all-trans retinoic acid. These cells were then exposed to H2O2 for 24 h. The effects of RECA on H2O2-induced neural-like cells were assessed through cell viability, apoptosis, and reactive oxygen species (ROS) assays, as well as neurite length measurement. The gene expression levels of neuronal-specific and antioxidant markers were assessed by RT-qPCR analysis.

RESULTS

Pre-treatment with H2O2 for 24 hours, in a dose-dependent manner, damaged neural-like cells as marked by a decrease in cell viability, substantial increase in intracellular ROS accumulation, and increase in apoptotic rate compared to untreated cells. These cells were used to treat with RECA. Treatment with RECA for 48 h remarkably restored cell survival and promoted neurite outgrowth in the H2O2- damaged neurons by increasing cell viability and decreasing ROS activity. RT-qPCR analysis revealed that RECA upregulated the level of antioxidant genes such as thioredoxin-1 (Trx-1) and heme oxygenase-1 (HO-1) of treated cells, as well as the expression level of neuronal-specific markers such as Tuj1 and MAP2 genes, suggesting their contribution in neuritogenic effect.

CONCLUSION

Our findings indicate that RECA promotes neuroregenerative effects and exhibits antioxidant properties, suggesting a valuable synergistic activity of its phytochemical constituents, thus, making the extract a promising candidate in preventing or treating oxidative stress-associated Alzheimer's disease.

Salidroside in the Treatment of NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is the commonest reason for chronic liver diseases in the world and is commonly related to the hepatic manifestation of the metabolic syndrome. Non-alcoholic steatohepatitis (NASH) is a deteriorating form of NAFLD, which can eventually develop into fibrosis, cirrhosis, and liver cancer. The reason for NAFLD/NASH development is complicated, such as liver lipid metabolism, oxidative stress, inflammatory response, apoptosis and autophagy, liver fibrosis and gut microbiota. Apart from bariatric surgery and lifestyle changes, officially approved drug therapy for NAFLD/NASH treatment is lacking. Salidroside (SDS) is a phenolic compound extensively distributed in the tubers of Rhodiola plants, which possesses many significant biological activities. This review summarized the related targets regulated by SDS in treating NAFLD/NASH. It is indicated that SDS could improve the status of NAFLD/NASH by ameliorating abnormal lipid metabolism, inhibiting oxidative stress, regulating apoptosis and autophagy, reducing inflammatory response, alleviating fibrosis and regulating gut microbiota. In conclusion, although the multiple bioactivities of SDS have been confirmed, the clinical data are inadequate and need to become the focus of attention in the later study.

Clinical relevance of biomarkers, new therapeutic approaches, and role of post-translational modifications in the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder that causes progressive loss of cognitive functions like thinking, memory, reasoning, behavioral abilities, and social skills thus affecting the ability of a person to perform normal daily functions independently. There is no definitive cure for this disease, and treatment options available for the management of the disease are not very effective as well. Based on histopathology, AD is characterized by the accumulation of insoluble deposits of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs). Although several molecular events contribute to the formation of these insoluble deposits, the aberrant post-translational modifications (PTMs) of AD-related proteins (like APP, Aβ, tau, and BACE1) are also known to be involved in the onset and progression of this disease. However, early diagnosis of the disease as well as the development of effective therapeutic approaches is impeded by lack of proper clinical biomarkers. In this review, we summarized the current status and clinical relevance of biomarkers from cerebrospinal fluid (CSF), blood and extracellular vesicles involved in onset and progression of AD. Moreover, we highlight the effects of several PTMs on the AD-related proteins, and provide an insight how these modifications impact the structure and function of proteins leading to AD pathology. Finally, for disease-modifying therapeutics, novel approaches, and targets are discussed for the successful treatment and management of AD.

Quercetin Increases Mitochondrial Biogenesis and Reduces Free Radicals in Neuronal SH-SY5Y Cells

Alzheimer’s disease (AD) is a common neurodegenerative disorder that causes dementia and affects millions of people worldwide. The mechanism underlying AD is unclear; however, oxidative stress and mitochondrial biogenesis have been reported to be involved in AD progression. Previous research has also reported the reduction in mitochondrial biogenesis in the brains of patients with AD. Quercetin (QE), a type of polyphenol, has been found to be capable of increasing mitochondrial biogenesis in the body. Accordingly, we explored whether QE could reduce amyloid beta (Aβ) accumulation caused by hydrogen peroxide (H₂O₂)-induced oxidative stress in SH-SY5Y cells. Our results revealed that QE stimulated the expression of mitochondrial-related proteins such as SIRT1, PGC-1α, and TFAM and subsequently activated mitochondrial biogenesis. Additionally, QE increased ADAM10 expression but reduced H₂O₂-induced reactive oxygen species production, apoptosis, β-site amyloid precursor protein cleaving enzyme 1 expression, and Aβ accumulation in the SH-SY5Y cells. These findings indicate that QE can effectively elevate mitochondrial biogenesis-related proteins and reduce the damage caused by oxidative stress, making it a promising option for protecting neuronal cells.

Dietary Supplementation of Salidroside Alleviates Liver Lipid Metabolism Disorder and Inflammatory Response to Promote Hepatocyte Regeneration via PI3K/AKT/Gsk3-β Pathway

Fatty liver hemorrhagic syndrome (FLHS) is a chronic hepatic disease which occurs when there is a disorder in lipid metabolism. FLHS is often observed in caged laying hens and characterized by a decrease in egg production and dramatic increase of mortality. Salidroside (SDS) is an herbal drug which has shown numerous pharmacological activities, such as protecting mitochondrial function, attenuating cell apoptosis and inflammation, and promoting antioxidant defense system. We aimed to determine the therapeutic effects of SDS on FLHS in laying hens and investigate the underlying mechanisms through which SDS operates these functions. We constructed oleic acid (OA)-induced fatty liver model in vitro and high-fat diet-induced FLHS of laying hens in vivo. The results indicated that SDS inhibited OA-induced lipid accumulation in chicken primary hepatocytes, increased hepatocyte activity, elevated the mRNA expression of proliferation related genes PCNA, CDK2, and cyclinD1 and increased the protein levels of PCNA and CDK2 (P < 0.05), as well as decreased the cleavage levels of Caspase-9, Caspase-8, and Caspase-3 and apoptosis in hepatocytes (P < 0.05). Moreover, SDS promoted the phosphorylation levels of PDK1, AKT, and Gsk3-β, while inhibited the PI3K inhibitor (P < 0.05). Additionally, we found that high-fat diet-induced FLHS hens had heavier body weight, liver weight, and abdominal fat weight, and severe steatosis in histology, compared with the control group (Con). However, hens fed with SDS maintained lighter body weight, liver weight, and abdominal fat weight, as well as normal liver without hepatic steatosis. In addition, high-fat diet-induced FLHS hens had high levels of serum total cholesterol (TC), triglyceride (TG), alanine transaminase (ALT), and aspartate aminotransferase (AST) compared to the Con group, however, in the Model+SDS group, the levels of TC, TG, ALT, and AST decreased significantly, whereas the level of superoxide dismutase (SOD) increased significantly (P < 0.05). We also found that SDS significantly decreased the mRNA expression abundance of PPARγ, SCD, and FAS in the liver, as well as increased levels of PPARα and MTTP, and decreased the mRNA expression of TNF-α, IL-1β, IL-6, and IL-8 in the Model+SDS group (P < 0.05). In summary, this study showed that 0.3 mg/mL SDS attenuated ROS generation, inhibited lipid accumulation and hepatocyte apoptosis, and promoted hepatocyte proliferation by targeting the PI3K/AKT/Gsk3-β pathway in OA-induced fatty liver model in vitro, and 20 mg/kg SDS alleviated high-fat-diet-induced hepatic steatosis, oxidative stress, and inflammatory response in laying hens in vivo.

Rhodiola Rosea Extract Counteracts Stress in an Adaptogenic Response Curve Manner via Elimination of ROS and Induction of Neurite Outgrowth

Background

Sustained stress with the overproduction of corticosteroids has been shown to increase reactive oxygen species (ROS) leading to an oxidative stress state. Mitochondria are the main generators of ROS and are directly and detrimentally affected by their overproduction. Neurons depend almost solely on ATP produced by mitochondria in order to satisfy their energy needs and to form synapses, while stress has been proven to alter synaptic plasticity. Emerging evidence underpins that Rhodiola rosea, an adaptogenic plant rich in polyphenols, exerts antioxidant, antistress, and neuroprotective effects.

Methods

In this study, the effect of Rhodiola rosea extract (RRE) WS®1375 on neuronal ROS regulation, bioenergetics, and neurite outgrowth, as well as its potential modulatory effect on the brain derived neurotrophic factor (BDNF) pathway, was evaluated in the human neuroblastoma SH-SY5Y and the murine hippocampal HT22 cell lines. Stress was induced using the corticosteroid dexamethasone.

Results

RRE increased bioenergetics as well as cell viability and scavenged ROS with a similar efficacy in both cells lines and counteracted the respective corticosteroid-induced dysregulation. The effect of RRE, both under dexamethasone-stress and under normal conditions, resulted in biphasic U-shape and inverted U-shape dose response curves, a characteristic feature of adaptogenic plant extracts. Additionally, RRE treatment promoted neurite outgrowth and induced an increase in BDNF levels.

Conclusion

These findings indicate that RRE may constitute a candidate for the prevention of stress-induced pathophysiological processes as well as oxidative stress. Therefore, it could be employed against stress-associated mental disorders potentially leading to the development of a condition-specific supplementation.

Salidroside orchestrates metabolic reprogramming by regulating the Hif-1α signalling pathway in acute mountain sickness

CONTEXT

Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba (Crassulaceae) is used to prevent and treat acute mountain sickness. However, the mechanisms underlying its effects on the central nervous system remain unclear.

OBJECTIVE

To investigate the effect of Rhodiola crenulata on cellular metabolism in the central nervous system.

MATERIALS AND METHODS

The viability and Hif-1α levels of microglia and neurons at 5% O₂ for 1, 3, 5 and 24 h were examined. We performed the binding of salidroside (Sal), rhodiosin, tyrosol and p-hydroxybenzyl alcohol to Hif-1α, Hif-1α, lactate, oxidative phosphorylation and glycolysis assays. Forty male C57BL/6J mice were divided into control and Sal (25, 50 and 100 mg/kg) groups to measure the levels of Hif-1α and lactate.

RESULTS

Microglia sensed low oxygen levels earlier than neurons, accompanied by elevated expression of Hif-1α protein. Salidroside, rhodiosin, tyrosol, and p-hydroxybenzyl alcohol decreased BV-2 (IC₅₀=1.93 ± 0.34 mM, 959.74 ± 10.24 μM, 7.47 ± 1.03 and 8.42 ± 1.63 mM) and PC-12 (IC₅₀=6.89 ± 0.57 mM, 159.28 ± 8.89 μM, 8.65 ± 1.20 and 8.64 ± 1.42 mM) viability. They (10 μM) reduced Hif-1α degradation in BV-2 (3.7-, 2.5-, 2.9- and 2.5-fold) and PC-12 cells (2.8-, 2.8-, 2.3- and 2.0-fold) under normoxia. Salidroside increased glycolytic capacity but attenuated oxidative phosphorylation. Salidroside (50 and 100 mg/kg) treatment increased the protein expression of Hif-1α and the release of lactate in the brain tissue of mice.

CONCLUSIONS

These results suggest that Sal induces metabolic reprogramming by regulating the Hif-1α signalling pathway to activate compensatory responses, which may be the core mechanism underlying the effect of Rhodiola crenulata on the central nervous system.

Salidroside protects against ventilation-induced lung injury by inhibiting the expression of matrix metalloproteinase-9

CONTEXT

Salidroside, a compound extracted from Rhodiola rosea L. (Crassulaceae), possesses many beneficial pathological effects.

OBJECTIVE

To explore the effect of salidroside on ventilator-induced lung endothelial dysfunction in vivo and in vitro.

MATERIALS AND METHODS

In vivo, male ICR mice were divided into sham, ventilation, salidroside, and ventilation plus salidroside groups. The mice were ventilated for 4 h, salidroside (50 mg/kg) was administrated intraperitoneally before ventilation, dexamethasone (Dex) (5 mg/kg) was used as a positive control. In vitro, mouse lung vascular endothelial cells (MLVECs) were treated with salidroside, MMP-9 siRNA, and BAY11-7082 (10 μM), and then exposed to cyclic stretch for 4 h. Afterward, lung tissues and MLVECs were collected for further analysis.

RESULTS

Salidroside pre-treatment significantly reversed the expression of vascular endothelial cadherin (VE-cadherin) and zonula occluden-1 (ZO-1) proteins in cyclic stretch-treated MLVECs (0.46 ± 0.09 vs. 0.80 ± 0.14, 0.49 ± 0.05 vs. 0.88 ± 0.08) and ventilated lung tissues (0.56 ± 0.06 vs. 0.83 ± 0.46, 0.49 ± 0.08 vs. 0.80 ± 0.12). The results further indicated that salidroside inhibited the expression of matrix metalloproteinase-9 (MMP-9), whereas knockdown of its expression restored the expression levels of VE-cadherin (0.37 ± 0.08 vs. 0.85 ± 0.74) and ZO-1 (0.48 ± 0.08 vs. 0.81 ± 0.11) in stretched MLVECs. Meanwhile, salidroside inhibited the NF-κB signalling pathway and alleviated lung injury.

CONCLUSIONS

Salidroside protected against stretch-induced endothelial barrier function, improving lung injury after ventilation. Thus, salidroside may be a promising therapeutic agent for patients with MV-induced lung injury.

Preclinical Evidence and Possible Mechanisms of Rhodiola rosea L. and Its Components for Ischemic Stroke: A Systematic Review and Meta-Analysis

Background: Rhodiola rosea L. has long been used as traditional medicines in Europe and Asia to treat a variety of common conditions and diseases including Alzheimer's disease, cardiovascular disease, cognitive dysfunctions, cancer, and stroke. Previous studies reported that Rhodiola rosea L. and its components (RRC) improve ischemia stroke in animal models. Here, we conducted a systematic review and meta-analysis for preclinical studies to evaluate the effects of RRC and the probable neuroprotective mechanisms in ischemic stroke. Methods: Studies of RRC on ischemic stroke animal models were searched in seven databases from inception to Oct 2021. The primary measured outcomes included the neural functional deficit score (NFS), infarct volume (IV), brain water content, cell viability, apoptotic cells, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells, B-cell lymphoma-2 (Bcl-2) level and tumor necrosis factor-α (TNF-α) level. The secondary outcome measures were possible mechanisms of RRC for ischemic stroke. All the data were analyzed via RevMan version 5.3. Results: 15 studies involving 345 animals were identified. Methodological quality for each included studies was accessed according to the CAMARADES 10-item checklist. The quality score of studies range from 1 to 7, and the median was 5.53. Pooled preclinical data showed that compared with the controls, RRC could improve NFS (Zea Longa (p < 0.01), modified neurological severity score (mNSS) (p < 0.01), rotarod tests (p < 0.01), IV (p < 0.01), as well as brain edema (p < 0.01). It also can increase cell viability (p < 0.01), Bcl-2 level (p < 0.01) and reduce TNF-α level (p < 0.01), TUNEL-positive cells (p < 0.01), apoptotic cells (p < 0.01). Conclusion: The findings suggested that RRC can improve ischemia stroke. The possible mechanisms of RRC are largely through antioxidant, anti-apoptosis activities, anti-inflammatory, repressing lipid peroxidation, antigliosis, and alleviating the pathological blood brain barrier damage.

Curcumin induces autophagic cell death in human thyroid cancer cells

Curcumin, a polyphenolic compound, is a well-known anticancer agent, although its poor bioavailability remains a big concern. Recent studies suggest that autophagy-targeted therapy may be a useful adjunct treatment for patients with thyroid cancer. Curcumin acts as an autophagy inducer on many cancer cells. However, little is known about the exact role of curcumin on thyroid cancer cells. In the present study, curcumin significantly inhibited the growth of thyroid cancer cells. Autophagy was markedly induced by curcumin treatment as evidenced by an increase in LC3-II conversion, beclin-1 accumulation, p62 degradation as well as the increased formation of acidic vesicular organelles (AVOs). 3-MA, an autophagy inhibitor, partially rescued thyroid cancer cells from curcumin-induced cell death. Additionally, curcumin was found to exert selective cytotoxicity on thyroid cancer cells but not normal epithelial cells and acted as an autophagy inducer through activation of MAPK while inhibition of mTOR pathways. Hyperactivation of the AKT/mTOR axis was observed in the majority of PTC samples we tested, and thyroid cancer cell lines along with cancer tissue specimens sustained a low basal autophagic activity. Taken together, our results provide new evidence that inducing autophagic cell death may serve as a potential anti-cancer strategy to handle thyroid cancer.

Curcumin enhances the membrane trafficking of the sodium iodide symporter and augments radioiodine uptake in dedifferentiated thyroid cancer cells via suppression of the PI3K-AKT signaling pathway

Radioactive iodine (RAI) is commonly used to treat differentiated thyroid cancer (DTC). A major challenge is the dedifferentiation of DTC with the loss of radioiodine uptake. Patients with distant metastases have persistent or recurrent disease and develop resistance to RAI therapy due to tumor dedifferentiation. Hence, tumor redifferentiation to restore sensitivity to RAI therapy is considered a promising strategy to overcome RAI resistance. In the present study, curcumin, a natural polyphenolic compound, was found to re-induce cell differentiation and increase the expression of thyroid-specific transcription factors, TTF-1, TTF-2 and transcriptional factor paired box 8 (PAX8), and iodide-metabolizing proteins, including thyroid stimulating hormone receptor (TSHR), thyroid peroxidase (TPO) and sodium iodide symporter (NIS) in dedifferentiated thyroid cancer cell lines, BCPAP and KTC-1. Importantly, curcumin enhanced NIS glycosylation and its membrane trafficking, resulting in a significant improvement of radioiodine uptake in vitro. Additionally, AKT knockdown phenocopied the restoration of thyroid-specific gene expression; however, ectopic expressed AKT inhibited curcumin-induced up-regulation of NIS protein, demonstrating that curcumin might improve radioiodine sensitivity via the inhibition of the PI3K-AKT-mTOR signaling pathway. Our study demonstrates that curcumin could represent a promising adjunctive therapy for restoring iodide avidity and improve radioiodine therapeutic efficacy in patients with RAI-refractory thyroid carcinoma.

Neuroprotective Effect of Epalrestat on Hydrogen Peroxide-Induced Neurodegeneration in SH-SY5Y Cellular Model

Epalrestat (EPS) is a brain penetrant aldose reductase inhibitor, an approved drug currently used for the treatment of diabetic neuropathy. At near-plasma concentration, EPS induces glutathione biosynthesis, which in turn reduces oxidative stress in the neuronal cells. In this study, we found that EPS reduces neurodegeneration by inhibiting reactive oxygen species (ROS)-induced oxidative injury, mitochondrial membrane damage, apoptosis and tauopathy. EPS treatment up to 50 μM did not show any toxic effect on SH-SY5Y cell line (neuroblastoma cells). However, we observed toxic effect at a concentration of 100 μM and above. At 50 μM concentration, EPS showed better antioxidant activity against H₂O₂ (100 μM)-induced cytotoxicity, ROS formation and mitochondrial membrane damage in retinoic acid-differentiated SH-SY5Y cell line. Furthermore, our study revealed that 50 μM of EPS concentration reduced the glycogen synthase kinase-3 β (GSK3-β) expression and total tau protein level in H₂O₂ (100 μM)-treated cells. Findings from this study confirms the therapeutic efficacy of EPS on regulating Alzheimer's disease (AD) by regulating GSK3-β and total tau proteins phosphorylation, which helped to restore the cellular viability. This process could also reduce toxic fibrillary tangle formation and disease progression of AD. Therefore, it is our view that an optimal concentration of EPS therapy could decrease AD pathology by reducing tau phosphorylation through regulating the expression level of GSK3-β.

Neuroprotective effects of ethanolic extract from dry Rhodiola rosea L. rhizomes

Rhodiola rosea L. rhizome has been used as a traditional medicine to treat fatigue, depression, and cognitive dysfunction. We aimed to authenticate R. rosea L. rhizome using the DNA barcoding technique and to quantify its main compounds, total phenolics, total flavonoids, and antioxidant capacity, and then to investigate their neuroprotective effects. The sequences of internal transcribed spacer and trnH-psbA of R. rosea L. rhizomes showed a 99% identity with those of NCBI GenBank database according to BLAST searches. Analysis using reversed-phase HPLC revealed five main compounds in R. rosea L. rhizome. Rhodiola rosea L. rhizome and two bioactive compounds, salidroside and tyrosol, showed free radical scavenging activity. Rhodiola rosea L. rhizome and its identified compounds protected neuronal PC-12 cells against oxidative stress and showed moderate acetylcholinesterase inhibition. Taken together, these results suggest that R. rosea L. rhizomes with bioactives can be used as a functional ingredient with potential for neuroprotection.

Supplementary information

The online version of this article (doi:10.1007/s10068-020-00868-7) contains supplementary material, which is available to authorized users.

Neuroprotective Effects of Heat-Killed Lactobacillus plantarum 200655 Isolated from Kimchi Against Oxidative Stress

Oxidative stress plays an important role in exacerbating neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. In a previous study, Lactobacillus plantarum 200655 was shown to possess probiotic and antioxidant potential. The current study aimed to evaluate the neuroprotective effects of heat-killed L. plantarum 200655. We incubated intestinal cells (HT-29) with heat-killed L. plantarum 200655 in a conditioned medium (CM) and found that the brain-derived neurotrophic factor (BDNF) mRNA level was elevated in the HT-29 cells and the CM contained high concentrations of BDNF. The CM protected neuroblastoma cells (SH-SY5Y) from hydrogen peroxide (H₂O₂)-induced toxicity. Moreover, the CM increased BDNF and tyrosine hydroxylase (TH) mRNA expression and significantly reduced the apoptosis-related Bax/Bcl-2 ratio in H₂O₂-treated SH-SY5Y cells. At the protein level, the CM resulted in downregulation of caspase-3. These results indicate that L. plantarum 200655 might be used as a prophylactic functional ingredient to prevent neurodegenerative disease.

The Potential Roles of Redox Enzymes in Alzheimer's Disease: Focus on Thioredoxin

Alzheimer's disease (AD) is the most common neurodegenerative diseases. Increasing studies have demonstrated the critical importance for redox proteins mediating neuronal protection in models of AD. This review briefly describes some of the risk factors contributing to AD, specifically highlighting the important roles of oxidative stress in the pathology of AD. Then this article concisely introduces the dysregulation and functions of two main redox enzymes, peroxiredoxins and glutaredoxins, in AD models. This review emphasizes the neuroprotective role of the third redox enzyme thioredoxin (Trx), an important multifunctional protein regulating cellular redox status. This commentary not only summarizes the alterations of Trx expression in AD patients and models, but also reviews the potential effects and mechanisms of Trx, Trx-related molecules and Trx-inducing compounds against AD. In conclusion, Trx has a potential neuroprotection in AD and may be very promising for clinical therapy of AD in the future.

Evolution of the adaptogenic concept from traditional use to medical systems: Pharmacology of stress- and aging-related diseases

Adaptogens comprise a category of herbal medicinal and nutritional products promoting adaptability, resilience, and survival of living organisms in stress. The aim of this review was to summarize the growing knowledge about common adaptogenic plants used in various traditional medical systems (TMS) and conventional medicine and to provide a modern rationale for their use in the treatment of stress-induced and aging-related disorders. Adaptogens have pharmacologically pleiotropic effects on the neuroendocrine-immune system, which explain their traditional use for the treatment of a wide range of conditions. They exhibit a biphasic dose-effect response: at low doses they function as mild stress-mimetics, which activate the adaptive stress-response signaling pathways to cope with severe stress. That is in line with their traditional use for preventing premature aging and to maintain good health and vitality. However, the potential of adaptogens remains poorly explored. Treatment of stress and aging-related diseases require novel approaches. Some combinations of adaptogenic plants provide unique effects due to their synergistic interactions in organisms not obtainable by any ingredient independently. Further progress in this field needs to focus on discovering new combinations of adaptogens based on traditional medical concepts. Robust and rigorous approaches including network pharmacology and systems pharmacology could help in analyzing potential synergistic effects and, more broadly, future uses of adaptogens. In conclusion, the evolution of the adaptogenic concept has led back to basics of TMS and a new level of understanding of holistic approach. It provides a rationale for their use in stress-induced and aging-related diseases.

Anti-Neuroinflammatory Potential of Polyphenols by Inhibiting NF-κB to Halt Alzheimer's Disease

Alzheimer's disease (AD) is an irrevocable chronic brain disorder featured by neuronal loss, microglial accumulation, and progressive cognitive impairment. The proper pathophysiology of this life-threatening disorder is not completely understood and no exact remedies have been found yet. Over the last few decades, research on AD has mainly highlighted pathomechanisms linked to a couple of the major pathological hallmarks, including extracellular senile plaques made of amyloid-β (Aβ) peptides, and intracellular neurofibrillary tangles (NFTs) made of tau proteins. Aβ can induce apoptosis, trigger an inflammatory response, and inhibit the synaptic plasticity of the hippocampus, which ultimately contributes to reducing cognitive functions and memory impairment. Recently, a third disease hallmark, the neuroinflammatory reaction that is mediated by cerebral innate immune cells, has become a spotlight in the current research area, assured by pre-clinical, clinical, and genetic investigations. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a cytokine producer, is significantly associated with physiological inflammatory proceedings and thus shows a promising candidate for inflammation- based AD therapy. Recent data reveal that phytochemicals, mainly polyphenol compounds, exhibit potential neuroprotective functions and these may be considered as a vital resource for discovering several drug candidates against AD. Interestingly, phytochemicals can easily interfere with the signaling pathway of NF-κB. This review represents the anti-neuroinflammatory potential of polyphenols as inhibitors of NF-κB to combat AD pathogenesis.

Effects of late-onset dietary intake of salidroside on insulin/insulin-like growth factor-1 (IGF-1) signaling pathway of the annual fish Nothobranchius guentheri

Salidroside (SDS) is the main active ingredient of Rhodiola which has many biological functions including anti-fatigue, anti-tumor, and immune regulation activities. Our last paper demonstrated that SDS prolonged longevity of the annual fish Nothobranchius guentheri, a promising vertebrate model for anti-aging research. However, little is known about its effect on insulin/insulin-like growth factor-1 (IGF-1) signaling pathway (IIS pathway). In this study, we show that SDS is able to decrease accumulation of SA-β-Gal. We also show that SDS administraton could reduce the expression levels of Igf-1 and Igf-1R, downregulate the expressions of p-PI3K and p-Akt and upregulate the expression levels of Sirt1 and Foxo3a, both of which are the downstream regulators of the IIS pathway. We also find that SDS could alleviate DNA damage, which could result in increased expression of transcription factor Foxo3a. Collectively, these data indicate that SDS may take part in the IIS pathway.

Neuroprotective Effect Of Peptide Fractions from Chia (Salvia hispanica) on H2O2-Induced Oxidative Stress-Mediated Neuronal Damage on N1E-115 Cell Line

Neurodegenerative diseases (ND) affect around a billion people worldwide. Oxidative stress plays a critical role in the activation of neuronal death mechanisms, implicated in the ND etiology. In the present research, the neuroprotective effect of the S. hispanica protein derivatives is evaluated, on neuronal cells N1E-115, after the damage induction with H₂O₂. From the protein-rich fraction of S. hispanica, three peptide fractions were obtained (3-5, 1-3 y < 1 kDa) and its neuroprotective effect on neuronal cells N1E-115 was evaluated, through the antioxidant pathway. In the toxicity assay, the peptide fractions showed viability greater than 90%. When N1E-115 cells were incubated with 100 µM H₂O₂, fractions 1-3 and < 1 kDa, presented cell viability of 66.64% ± 3.2 and 67.32% ± 2.8, respectively. Fractions 1-3 and < 1 kDa reduced by 41.73% ± 3.2 and 40.87% ± 2.8, respectively, the ROS production compared to the control, without significant statistical difference between both fractions (p < 0.05), while F3-5 kDa, only reduced the ROS production by 21.95% ± 2.4. The protective effect observed in the < 3 kDa fractions could be associated with its antioxidant activity, which represents an important study target.

Protective Evaluation of Compounds Extracted from Root of Rhodiola rosea L. against Methylglyoxal-Induced Toxicity in a Neuronal Cell Line

Rhodiola rosea L. (R. rosea) is one of the most beneficial medicinal plants and it is studied as an adaptogen. This study aims to evaluate the neuroprotective activity of compounds extracted from the root of R. rosea against methylglyoxal (MG)-induced apoptosis in neuro-2A (N2A) cells. The root of R. rosea was extracted with ethanol and partitioned with water, ethyl acetate, and n-butanol fractions to evaluate acetylcholinesterase (AChE) inhibitory activity and neuroprotective activity. The ethyl acetate fraction exhibited the highest values of AChE inhibitory activity (49.2% ± 3%) and cell viability (50.7% ± 4.8%) for neuroprotection. The structure identification of the most potential fraction (ethyl acetate fraction) revealed 15 compounds, consisting of three tannins, five flavonoids, and seven phenolics by infrared spectroscopy, nuclear magnetic resonance, and mass spectroscopy. All compounds were evaluated for their neuroprotective activity. Salidroside had the most potential neuroprotective activity. Gallic acid and methyl gallate had potential cytotoxicity in N2A cells. This study showed that R. rosea might have potential neuroprotective activities.

Neuroprotective Activity of Mentha Species on Hydrogen Peroxide-Induced Apoptosis in SH-SY5Y Cells

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with an unclear cause. It appears that multiple factors participate in the process of neuronal damage including oxidative stress and accumulation of the protein amyloid β (Aβ) in the brain. The search for a treatment for this disorder is essential as current medications are limited to alleviating symptoms and palliative effects. The aim of this study is to investigate the effects of mint extracts on selected mechanisms implicated in the development of AD. To enable a thorough investigation of mechanisms, including effects on β-secretase (the enzyme that leads to the formation of Aβ), on Aβ aggregation, and on oxidative stress and apoptosis pathways, a neuronal cell model, SH-SY5Y cells, was selected. Six Mentha taxa were investigated for their in vitro β-secretase (BACE) and Aβ-aggregation inhibition activities. Moreover, their neuroprotective effects on H₂O₂-induced oxidative stress and apoptosis in SH-SY5Y cells were evaluated through caspase activity. Real-time PCR and Western blot analysis were carried out for the two most promising extracts to determine their effects on signalling pathways in SH-SY5Y cells. All mint extracts had strong BACE inhibition activity. M. requienii extracts showed excellent inhibition of Aβ-aggregation, while other extracts showed moderate inhibition. M. diemenica and M. requienii extracts lowered caspase activity. Exposure of SH-SY5Y cells to M. diemenica extracts resulted in a decrease in the expression of pro-apoptotic protein, Bax, and an elevation in the anti-apoptotic protein, Bcl-xL, potentially mediated by down-regulation of the ASK1-JNK pathway. These results indicate that mint extracts could prevent the formation of Aβ and also could prevent their aggregation if they had already formed. M. diemenica and M. requienii extracts have potential to suppress apoptosis at the cellular level. Hence, mint extracts could provide a source of efficacious compounds for a therapeutic approach for AD.

TV 3326 for Alzheimer's dementia: a novel multimodal ChE and MAO inhibitors to mitigate Alzheimer's-like neuropathology

OBJECTIVES

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders and a well-recognized cause of dementia with ageing. In this review, we have represented the ChE and MAO inhibitory potential of TV 3326 against AD based on current scientific evidence.

KEY FINDINGS

The aetiology of AD is quite complex and not completely understood. However, it has been observed that AD involves the deposition of abnormal amyloid beta (Aβ), along with hyperphosphorylation of tau, oxidative stress, low acetylcholine (ACh) level and biometal dyshomeostasis. Due to the complex nature of AD aetiology, active research is required in the areas of development of multitarget drugs with 2 or more complementary biological functions, as they might represent significant progress in the AD treatment. Interestingly, it has been found that TV 3326 (i.e. ladostigil) is regarded as a novel therapeutic agent since it has the potential to cause inhibition of monoamine oxidase (MAO) A and B, and acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the brain. Furthermore, it has the capacity to reverse memory impairments, which further suggests the ability of this drug to elevate cholinergic activity in the brain.

SUMMARY

TV 3326 can avert oxidative-nitrative stress and gliosis. It has also been confirmed that TV 3326 contains neuroprotective and anti-apoptotic properties. Therefore, this distinctive combined inhibition of ChE and MAO along with its neuroprotective property makes TV 3326 a useful drug in the treatment of AD.

Nanoencapsulation of synergistic antioxidant fruit and vegetable concentrates and their stability during in vitro digestion

BACKGROUND

Natural antioxidants have received increased attention owing to their safe use without side effects; however, their application has been limited because of lower antioxidant activity and stability during digestion when compared with those of synthetic antioxidants. Although research is ongoing to overcome these problems, it is still challenging to find effective solutions. In this study, we aimed to improve the properties and stability of natural antioxidants during in vitro digestion by synergistic combination and nanoencapsulation.

RESULTS

Ten selected fruit and vegetable concentrates (acai berry, aronia, blackberry, cranberry, wild berry, raspberry, blueberry, red grape, cabbage, and spinach) were evaluated for their antioxidant capacity when combined via the oxygen radical absorbance capacity (ORAC) assay. Among the 45 combinations, the highest synergistic ORAC value was noted for the blueberry and cabbage concentrates (BUCA; 0.8 and 1.2 mg mL^-1 ) at an antioxidant ratio of 5:5. Chitosan/carrageenan (CSCR) nanoparticles are physically more stable than chitosan/gum arabic nanoparticles during in vitro digestion and were selected for the oral delivery of BUCA. Under simulated intestinal conditions, BUCA-loaded CSCR nanoparticles showed significantly more stable antioxidant activity and total phenolic content than non-nanoencapsulated BUCA. The highest antioxidant stability was observed in the BUCA-loaded CSCR nanoparticles prepared with 0.2 mg mL^-1 carrageenan, which showed two-times higher ORAC value and ten-times higher total phenolic content than non-nanoencapsulated BUCA after 12 h of in vitro digestion.

CONCLUSION

CSCR nanoencapsulation of natural antioxidants could be an effective technique for improving antioxidant stability during digestion. © 2019 Society of Chemical Industry.

A review on osteoclast diseases and osteoclastogenesis inhibitors recently developed from natural resources

Natural products have been investigated as potential candidates of novel therapeutics and play a crucial role in advanced medicinal drugs. Natural resources, including local medicinal plants (especially folk medicinal plants), animals, bacteria, and fungi have been used for more than a century, and are precious gifts from nature, providing potential medicines with high safety. Osteoclast-related diseases, such as osteoporosis, rheumatoid arthritis, Paget's disease, osteoclastoma, and periprosthetic osteolysis, are currently the most common reasons for bone inflammation, pain and fractures, resulting in low quality of life. However, the curative effects of current therapeutic drugs for these osteoclast-related diseases are limited, and long-term treatment is needed. Further, in severe cases, surgical treatments are necessary, which may cause unaffordable expenses and subsequent influences such as neuralgia, mental stress, and even development of cancer. Thus, safer inhibitors and potential drugs with enhanced curative effects and quick relief are needed to treat patients with osteoclast diseases. This review aims to introduce the main osteoclast-related diseases and some of the recently developed naturally sourced inhibitors against osteoclastogenesis, also it is desired to attract people's attention on using widely available natural resources for the evolution of new types of osteoclast inhibitors with minimal or no side-effects upon long-term treatments.

Inhibitory Effect of Probenecid on Osteoclast Formation via JNK, ROS and COX-2

Probenecid is a representative drug used in the treatment of gout. A recent study showed that probenecid effectively inhibits oxidative stress in neural cells. In the present study, we investigated whether probenecid can affect osteoclast formation through the inhibition of reactive oxygen species (ROS) formation in RAW264.7 cells. Lipopolysaccharide (LPS)-induced ROS levels were dose-dependently reduced by probenecid. Fluorescence microscopy analysis clearly showed that probenecid inhibits the generation of ROS. Western blot analysis indicated that probenecid affects two downstream signaling molecules of ROS, cyclooxygenase 2 (COX-2) and c-Jun N-terminal kinase (JNK). These results indicate that probenecid inhibits ROS generation and exerts antiosteoclastogenic activity by inhibiting the COX-2 and JNK pathways. These results suggest that probenecid could potentially be used as a therapeutic agent to prevent bone resorption.

Exploring the Multifunctional Neuroprotective Promise of Rasagiline Derivatives for Multi-Dysfunctional Alzheimer's Disease

Alzheimer's disease (AD) is a chronic, age-related, and irreversible brain disorder that typically develops slowly and gets worse over time. The potent auspicious drug candidate for the treatment of AD is supposed to perform the simultaneous modulation of several targets linked to AD. The new therapeutic approach involves drug candidates that are designed to act on multiple targets and have various pharmacological properties. This trend has triggered the development of various multimodal drugs including TV-3326 (i.e. ladostigil) and M-30 (i.e. a new multitarget iron chelator). TV-3326 combines the neurorestorative/neuroprotective effects of the cholinesterase (ChE) inhibitory activity of rivastigmine with rasagiline (a selective monoamine oxidase-B inhibitor and novel antiparkinsonian agent) in a single molecule. M-30, the second derivative of rasagiline, was developed by combining the propargyl moiety of rasagiline into the skeleton of VK-28 (i.e. a novel brain permeable neuroprotective iron chelator). It has been revealed that both the compounds possess anti-AD effects and therefore, the clinical development is directed to the treatment of this type of neurodegenerative diseases (NDs). In this article, we have reviewed the neuroprotective molecular mechanisms and multimodal effects of TV-3326 and M-30.

LncRNA EPIC1 downregulation mediates hydrogen peroxide-induced neuronal cell injury

Excessive oxidative stress causes neuronal cell injury. Long non-coding RNA (LncRNA) EPIC1 (Lnc-EPIC1) is a MYC-interacting LncRNA. Its expression and potential functions in hydrogen peroxide (H₂O₂)-stimulated neuronal cells are studied. In SH-SY5Y neuronal cells and primary human neuron cultures, H₂O₂ downregulated Lnc-EPIC1 and key MYC targets (Cyclin A1, CDC20 and CDC45). Ectopic overexpression of Lnc-EPIC1 increased expression of MYC targets and significantly attenuated H₂O₂-induced neuronal cell death and apoptosis. Contrarily, Lnc-EPIC1 siRNA potentiated neuronal cell death by H₂O₂. MYC knockout by CRISPR/Cas9 method also facilitated H₂O₂-induced SH-SY5Y cell death. Significantly, MYC knockout abolished Lnc-EPIC1-induced actions in H₂O₂-stimulated neuronal cells. Together, these results suggest that Lnc-EPIC1 downregulation mediates H₂O₂-induced neuronal cell death.

Characterization and screening of anti-tumor activity of fucoidan from acid-processed hijiki (Hizikia fusiforme)

The aim of this study was to investigate the antiproliferative effects of fucoidan from three regional hijiki (Hizikia fusiforme) samples (Zhejiang-China, Jeju-Korea [JH], and Wando-Korea) in East Asia. Hijiki was processed using 1% citric acid to decrease heavy metal content. The JH sample was separated using diethylaminoethyl-cellulose-ion exchange chromatography to obtain four active fractions (JHCF1-JHCF4) and their monosaccharide composition was detected using high-performance liquid chromatography. The structure of the crude polysaccharides and four fucoidan fractions was analyzed using Fourier-transform infrared spectroscopy. JHCF4 showed the highest fucose and sulfate content and decreased Hep3B cell growth in 48 h with a half-maximal inhibitory concentration of 33.53 ± 2.50 μg/ml, which represented the strongest anticancer activity. Further, nuclear staining with Hoechst 33342 and acridine orange-ethidium bromide staining demonstrated that the anticancer activity of JHCF4 was mediated by apoptosis. Moreover, JHCF4 down-regulated B-cell lymphoma extra-large, while up-regulating Bcl-2-associated X protein, caspase-3, and apoptotic bodies to different degrees in Hep3B cells. JHCF4 induced apoptosis via the generation of reactive oxygen species along with the concurrent loss of mitochondrial membrane potential, indicating the potential role of the mitochondria-mediated pathway. Therefore, these results indicate that JHCF4 exhibited antiproliferative effects on the investigated cancer cell lines.

Salidroside represses proliferation, migration and invasion of human lung cancer cells through AKT and MEK/ERK signal pathway

Salidroside, a glycoside of tyrosol, is isolated from Rhodiola rosea and shows anti-cancer functions in several cancers. However, the potentials of salidroside in the migration and invasion of lung cancer cells and its underlying mechanisms remain unknown. We aimed to investigate the functions and mechanisms of salidroside in non-small cell lung cancer (NSCLC). Human NSCLC cell line A549 was treated with different doses of salidroside. Cell viability, colony formation, apoptosis, migration and invasion were detected by CCK-8, crystal violet-staining assay, flow cytometry and transwell assay, respectively. qRT-PCR and western blot analysis were performed to assess the regulatory effects of salidroside on miR-195 expression and the activation of AKT and the MEK/ERK signal pathway. We found that, salidroside remarkably reduced cell viability, colony formation and Cyclin D1 expression, but increased p21 expression and apoptosis in A549 cells. Additionally, salidroside inhibited the migration and invasion of A549 cells by regulating expressions of migration- and invasion-related proteins. Finally, salidroside inhibited phosphorylation of AKT, MEK and ERK by upregulating miR-195 expression in A549 cells. In conclusion, salidroside inhibited the survival, migration and invasion of NSCLC cells. Salidroside blocked AKT and the MEK/ERK signal pathway by upregulating miR-195 expression in A549 cells.

Salidroside suppresses the growth and invasion of human osteosarcoma cell lines MG63 and U2OS in vitro by inhibiting the JAK2/STAT3 signaling pathway

Previous research has reported that salidroside exerts antitumor properties on numerous types of tumor cells; however, its effect on osteosarcoma cells remains unknown. The present study aimed to investigate the effects of salidroside on the viability, apoptosis and invasion of osteosarcoma cells in vitro, and determine the underlying mechanism of action. The results of an MTT revealed that salidroside suppressed the viability of osteosarcoma cells (MG63 and U2OS cells) in a time- and concentration-dependent manner. The results of cell morphological analysis (profile observations and Hoechst 33258 staining) and the detection of apoptosis by flow cytometry further indicated that the decrease in osteosarcoma cell viability induced by salidroside was associated with cell apoptosis. Western blot analysis not only confirmed these results but also suggested that salidroside induced the apoptosis of osteosarcoma cells by activating the caspase-9-dependent apoptotic pathway. In addition, we reported that salidroside induced G₀/G₁ phase arrest and suppressed the invasion of osteosarcoma cells, as measured by flow cytometric cell cycle analysis and a Transwell invasion assay, respectively. Western blot analysis confirmed the aforementioned results. Furthermore, our findings demonstrated that salidroside induced the apoptosis, G₀/G₁ phase arrest and suppressed the invasion of osteosarcoma cells by inhibiting the janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, as determined by western blot analysis. In summary, the findings of the present study suggested that salidroside may inhibit the progression of osteosarcoma by suppressing the growth and invasion of osteosarcoma cells. Furthermore, the investigations into the underlying mechanism demonstrated that salidroside exerted notable antitumor activity in osteosarcoma cells by inhibiting the JAK2/STAT3 signaling pathway.

Neuroprotective effect of salidroside against central nervous system inflammation-induced cognitive deficits: A pivotal role of sirtuin 1-dependent Nrf-2/HO-1/NF-κB pathway

Central nervous system (CNS) inflammation occurs in cognitive dysfunctions, but the underlying mechanisms remain unclear. Here, we investigated the role of sirtuin 1 (SIRT1) and salidroside in CNS inflammation-induced cognitive deficits model. In vivo, CNS inflammation was initiated by a single intracerebroventricular injection of lipopolysaccharide (LPS). The levels of inflammatory cytokines and the capability of free radial scavenging were determined after the LPS challenge. In vivo, salidroside and nicotinamide, a SIRT1 inhibitor, were used in PC12 cell. Of note, with the treatment of salidroside, LPS-induced learning and memory impairments were effectively improved. Salidroside also remarkably inhibited the inflammatory cytokines, up-regulated the concentration of superoxide dismutase and inhibited the vitalities of malondialdehyde in serum, hippocampus, and cell supernatant. Besides, the expression of Sirt1, Nrf-2, HO-1, Bax, Bcl-2, caspase-9, and caspase-3 and the phosphorylation of AMPK, NF-κBp65, and IκBα were increased accompanying with the LPS-induced cognitive impairments, which were significantly suppressed by salidroside treatment. In PC12 cell model, nicotinamide significantly abrogated the beneficial effects of salidroside, as indicated by the antioxidant, anti-inflammatory, and antiapoptosis signaling. Together, our results showed that salidroside may be a novel therapy drug in neurodegenerative diseases, and the protective effect was involved in SIRT1-dependent Nrf-2/HO-1/NF-κB pathway.