Arylbenzofuran isolated from Dalbergia odorifera suppresses lipopolysaccharide-induced mouse BV2 microglial cell activation, which protects mouse hippocampal HT22 cells death from neuroinflammation-mediated toxicity

The SIRT-1/Nrf2/HO-1 axis: Guardians of neuronal health in neurological disorders

SIRT1 (Sirtuin 1) is a NAD+-dependent deacetylase that functions through nucleoplasmic transfer and is present in nearly all mammalian tissues. SIRT1 is believed to deacetylate its protein substrates, resulting in neuroprotective actions, including reduced oxidative stress and inflammation, increased autophagy, increased nerve growth factors, and preserved neuronal integrity in aging or neurological disease. Nrf2 is a transcription factor that regulates the genes responsible for oxidative stress response and substance detoxification. The activation of Nrf2 guards cells against oxidative damage, inflammation, and carcinogenic stimuli. Several neurological abnormalities and inflammatory disorders have been associated with variations in Nrf2 activation caused by either pharmacological or genetic factors. Recent evidence indicates that Nrf2 is at the center of a complex cellular regulatory network, establishing it as a transcription factor with genuine pleiotropy. HO-1 is most likely a component of a defense mechanism in cells under stress, as it provides negative feedback for cell activation and mediator synthesis. This mediator is upregulated by Nrf2, nitric oxide (NO), and other factors in various inflammatory states. HO-1 or its metabolites, such as CO, may mitigate inflammation by modulating signal transduction pathways. Neurological diseases may be effectively treated by modulating the activity of HO-1. Multiple studies have demonstrated that SIRT1 and Nrf2 share an important connection. SIRT1 enhances Nrf2, activates HO-1, protects against oxidative injury, and decreases neuronal death. This has been associated with numerous neurodegenerative and neuropsychiatric disorders. Therefore, activating the SIRT1/Nrf2/HO-1 pathway may help treat various neurological disorders. This review focuses on the current understanding of the SIRT1 and Nrf2/HO-1 neuroprotective processes and the potential therapeutic applications of their target activators in neurodegenerative and neuropsychiatric disorders.

Polymer-Formulated Nerve Growth Factor Shows Effective Therapeutic Efficacy for Cerebral Microinfarcts

Cerebral microinfarcts represent the most prevalent form of ischemic brain injury in the elderly, particularly among those suffering from dementia, Alzheimer's disease, and vascular risk factors. Despite their commonality, effective treatments have remained elusive. Herein, a novel treatment utilizing a polymer-formulated nerve growth factor capable of crossing the blood-brain barrier is reported, which effectively reduced oxidative stress and neuronal apoptosis, reshaped microglia polarization at infarct sites, and decreased the overall microinfarct burden, leading to notable improvements in behavioral and cognitive functions in a mouse model. This work provides a promising new avenue for the treatment of cerebral microinfarcts and other neurodegenerative diseases.

The Standardized Extract of Centella asiatica and Its Fractions Exert Antioxidative and Anti-Neuroinflammatory Effects on Microglial Cells and Regulate the Nrf2/HO-1 Signaling Pathway

Background

Neuroinflammation and oxidative stress can aggravate the progression of Alzheimer's disease (AD). Centella asiatica has been traditionally consumed for memory and cognition. The triterpenes (asiaticoside, madecassoside, asiatic acid, madecassic acid) have been standardized in the ethanolic extract of Centella asiatica (SECA). The bioactivity of the triterpenes in different solvent polarities of SECA is still unknown.

Objective

In this study, the antioxidative and anti-neuroinflammatory effects of SECA and its fractions were explored on lipopolysaccharides (LPS)-induced microglial cells.

Methods

HPLC measured the four triterpenes in SECA and its fractions. SECA and its fractions were tested for cytotoxicity on microglial cells using MTT assay. NO, pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), ROS, and MDA (lipid peroxidation) produced by LPS-induced microglial cells were measured by colorimetric assays and ELISA. Nrf2 and HO-1 protein expressions were measured using western blotting.

Results

The SECA and its fractions were non-toxic to BV2 microglial cells at tested concentrations. The levels of NO, TNF-α, IL-6, ROS, and lipid peroxidation in LPS-induced BV2 microglial cells were significantly reduced (p < 0.001) by SECA and its fractions. SECA and some of its fractions can activate the Nrf2/HO-1 signaling pathway by significantly enhancing (p < 0.05) the Nrf2 and HO-1 protein expressions.

Conclusions

This study suggests that the inhibitory activity of SECA and its fractions on pro-inflammatory and oxidative stress events may be the result of the activation of antioxidant defense systems. The potential of SECA and its fractions in reducing neuroinflammation and oxidative stress can be further studied as a potential therapeutic strategy for AD.

Hydralazine inhibits neuroinflammation and oxidative stress in APP/PS1 mice via TLR4/NF-κB and Nrf2 pathways

Alzheimer's disease (AD) is a common chronic progressive neurodegenerative disorder, and curative treatment has not been developed. The objective of this study was to investigate the potential effects of hydralazine (Hyd, a hypertension treatment drug) on the development process of AD and its mechanisms. We treated 6-month-old male APP/PS1 mice with Hyd for 5 weeks, measured changes in behavior and pathological status, and analyzed differences in gene expression by RNA sequencing. The results demonstrated that Hyd improved cognitive deficits and decreased amyloid beta protein deposition in the cortex and hippocampus, while RNA sequencing analysis suggested that the regulation of neuroinflammation and energy metabolism might play pivotal roles for Hyd's beneficial effects. Therefore, we further investigated inflammatory response, redox state, and mitochondrial function, as well as the expression of toll-like receptor 4 (TLR4)/nuclear factor Kappa B (NF-κB)-dependent neuroinflammation gene and nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant gene in AD mice. The results showed that Hyd reduced the damage of neuroinflammation and oxidative stress, improved mitochondrial dysfunction, downregulated pro-inflammation gene expression, and upregulated antioxidant gene expression. The results in lipopolysaccharide (LPS)-induced BV2 cell model demonstrated that Hyd suppressed pro-inflammatory response via TLR4/NF-κB signaling pathway. In addition, by silencing the Nrf2 gene expression, it was found that Hyd can reduce LPS-induced reactive oxygen species production by activating the Nrf2 signaling pathway. Therefore, administration of Hyd in the early stage of AD might be beneficial in delaying the pathological development of AD via inhibiting neuroinflammation and oxidative stress.

Medication Rules in Herbal Medicine for Mild Cognitive Impairment: A Network Pharmacology and Data Mining Study

Background

Although traditional Chinese medicine (TCM) has good efficacy in the treatment of mild cognitive impairment (MCI), especially memory improvement and safety, its substance basis and intervention mechanism are particularly complex and unknown. Therefore, based on network pharmacology and data mining, this study aims to explore the rules, active ingredients and mechanism of TCM in the treatment of MCI.

Methods

By searching the GeneCard, OMIM, DisGeNET and DrugBank databases, we obtained the critical targets associated with MCI. We matched the components and herbs corresponding to the important targets in the TCMSP platform. Using Cytoscape 3.7.2 software, we constructed a target-component-herb network and conducted a network topology analysis to obtain the core components and herbs. Molecular docking was used to preliminarily analyze and predict the binding activities and main binding combinations of the core targets and components. Based on the analysis of the properties, flavor and meridian distribution of herbs, the rules of herbal therapy for MCI were summarized.

Results

Twenty-eight critical targets were obtained after the screening. Using the TCMSP platform, 492 components were obtained. After standardization, we obtained 387 herbs. Based on the target-composition-herb network analysis, the core targets were ADRB2, ADRA1B, DPP4, ACHE and ADRA1D. According to the screening, the core ingredients were beta-sitosterol, quercetin, kaempferol, stigmasterol and luteolin. The core herbs were matched to Danshen, Yanhusuo, Gancao, Gouteng and Jiangxiang. It was found that the herbs were mainly warm in nature, pungent in taste and liver and lung in meridian. The molecular docking results showed that most core components exhibited strong binding activity to the target combination regardless of the in or out of network combination.

Conclusion

The results of this study indicate that herbs have great potential in the treatment of MCI. This study provides a reference and basis for clinical application, experimental research and new drug development of herbal therapy for MCI.

Hypoxia-Induced Neuroinflammation in Alzheimer's Disease: Potential Neuroprotective Effects of Centella asiatica

Alzheimer's disease (AD) is a neurodegenerative disorder that is characterised by the presence of extracellular beta-amyloid fibrillary plaques and intraneuronal neurofibrillary tau tangles in the brain. Recurring failures of drug candidates targeting these pathways have prompted research in AD multifactorial pathogenesis, including the role of neuroinflammation. Triggered by various factors, such as hypoxia, neuroinflammation is strongly linked to AD susceptibility and/or progression to dementia. Chronic hypoxia induces neuroinflammation by activating microglia, the resident immune cells in the brain, along with an increased in reactive oxygen species and pro-inflammatory cytokines, features that are common to many degenerative central nervous system (CNS) disorders. Hence, interests are emerging on therapeutic agents and plant derivatives for AD that target the hypoxia-neuroinflammation pathway. Centella asiatica is one of the natural products reported to show neuroprotective effects in various models of CNS diseases. Here, we review the complex hypoxia-induced neuroinflammation in the pathogenesis of AD and the potential application of Centella asiatica as a therapeutic agent in AD or dementia.

Hydrogen Alleviates Neuronal Injury and Neuroinflammation Induced by Microglial Activation via the Nuclear Factor Erythroid 2-related Factor 2 Pathway in Sepsis-associated Encephalopathy

Sepsis-associated encephalopathy (SAE) is characterized by diffuse cerebral and central nervous system (CNS) dysfunction. Microglia play a vital role in protecting the brain from neuronal damage, which is closely related to inflammatory responses. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway has an impact on microglial and neuronal injury. Here, we mainly explored the molecular mechanism by which Hydrogen (H₂) regulates neuroinflammation in SAE and the role of Nrf2 in this process. An in vivo model of SAE was generated by cecal ligation and puncture (CLP). Primary microglia and neurons were cultured to establish an in vitro model. Microglia, neurons and brain tissue were obtained to detect Nrf2 expression, inflammation, cell injury, apoptosis, and microglial polarization. Escape latency, the number of platform crossings and the time spent in the target quadrant were measured to assess cognitive function. H₂ attenuated microglial polarization from the M1 to the M2 phenotype, cytokine release and TLR/NF-κb activation and protected neurons from lipopolysaccharide (LPS)-activated microglia-induced injury via the Nrf2 pathway. SAE activated Nrf2 expression, and H₂ further improved Nrf2 expression in SAE mice. H₂ alleviated microglial polarization from the M1 to the M2 phenotype and cytokine release in the cerebral cortex and improved neuronal injury or cognitive dysfunction in SAE mice and wild-type mice but not in Nrf2-/- mice. H₂ exerts antineuroinflammatory effects associated with TLR4/NF-κB signaling activation and neuroprotective effects by inhibiting the excessive release of proinflammatory cytokines, neuronal loss and apoptosis in vitro and in vivo through the Nrf2 pathway.

Endophytic Fungi from Dalbergia odorifera T. Chen Producing Naringenin Inhibit the Growth of Staphylococcus aureus by Interfering with Cell Membrane, DNA, and Protein

This study focused on the antibacterial effects of the endophytic fungi producing naringenin from Dalbergia odorifera T. Chen against Staphylococcus aureus. The antibacterial activity was measured by the inhibition diameters, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The time-killing curve was also used to evaluate its antibacterial efficacy. The results of antibacterial activity determinations showed that endophytic fungi secondary metabolites can inhibit the growth of five pathogenic bacteria (S. aureus, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, and Bacillus subtilis) and the most sensitive strain was S. aureus that had the MIC and MBC values of 0.13 and 0.50 mg/mL, respectively. The membrane permeability study was measured by a DNA leakage assay and electrical conductivity assay. Furthermore, the whole-cell protein lysates and DNA fragmentation assay was evaluated. The morphology of S. aureus treated with the endophytic fungi products was observed by scanning electron microscopy (SEM). The probable antibacterial mechanism of endophytic fungi secondary metabolites was the increased membrane permeability that leads to leaks of nucleic acids and proteins. SEM results further confirmed that the extracts can interfere with the integrity of S. aureus cell membrane and further inhibit the growth of bacteria, resulting in the death of bacteria. This study provides a new perspective for the antibacterial functions of endophytic fungi secondary metabolites for biomedical applications.

Inflammation in Bipolar Disorder (BD): Identification of new therapeutic targets

Bipolar disorder (BD) is a chronic and cyclic mental disorder, characterized by unusual mood swings between mania/hypomania and depression, raising concern in both scientific and medical communities due to its deleterious social and economic impact. Polypharmacy is the rule due to the partial effectiveness of available drugs. Disease course is often unremitting, resulting in frequent cognitive deficits over time. Despite all research efforts in identifying BD-associated molecular mechanisms, current knowledge remains limited. However, the involvement of inflammation in BD pathophysiology is increasingly consensual, with the immune system and neuroinflammation playing a key role in disease course. Evidence includes altered levels of cytokines and acute-phase proteins, pathological microglial activation, deregulation of Nrf2-Keap1 system and changes in biogenic amines neurotransmitters, whose expression is regulated by TNF-α, a pro-inflammatory cytokine highly involved in BD, pointing out inflammation as a novel and attractive therapeutic target for BD. As result, new therapeutic agents including non-steroidal anti-inflammatory drugs, N-acetylcysteine and GSK3 inhibitors have been incorporated in BD treatment. Taking into consideration the latest pre-clinical and clinical trials, in this review we discuss recent data regarding inflammation in BD, unveiling potential therapeutic approaches through direct or indirect modulation of inflammatory response.

6,4'-dihydroxy-7-methoxyflavanone protects against H2O2-induced cellular senescence by inducing SIRT1 and inhibiting phosphatidylinositol 3-kinase/Akt pathway activation

6, 4'-Dihydroxy-7-methoxyflavanone (DMF) has been shown to possess anti-inflammatory, anti-oxidative, and neuroprotective activities. However, its effect on oxidative stress-induced aging remains undemonstrated. This study aimed at investigating the anti-senescence effect of DMF on hydrogen peroxide (H₂O₂)-induced premature senescence, and associated molecular mechanisms in human dermal fibroblasts (HDFs). The cells were DMF pretreated with small interfering RNA (siRNAs) of control or sirtuin 1 (SIRT1) before H₂O₂ exposure, and western blot analysis, senescence-associated β-galactosidase (SA-β-gal) activity, cell counting, gene silencing, and SIRT1 activity assay were performed. Pretreatment with DMF inhibited H₂O₂-induced senescence phenotypes, which showed decreased SA-β-gal activity and increased cell growth in comparison with H₂O₂-treated HDFs. Meanwhile, the decreases in ac-p53, p21^Cip1/WAF1, and p16^Ink4a and the increases in pRb and cyclin D1 were observed. DMF was also found to induce SIRT1 expression and activity level concentration- and time-dependently. Moreover, SIRT1 inhibition abrogated DMF senescence prevention. Additionally, Akt and ERK were activated with different kinetics after H₂O₂ exposure, and Akt activity inhibition attenuated SA-β-gal activity augmentation. We also found that DMF inhibited H₂O₂-induced Akt phosphorylation. This study indicates that DMF effectively protects against oxidative stress-induced premature senescence through SIRT1 expression up-regulation and Akt pathway inhibition in HDFs. These results suggest that DMF can be a potential therapeutic molecule for age-related diseases, or a protective agent against the aging process.

Forsythoside B attenuates memory impairment and neuroinflammation via inhibition on NF-κB signaling in Alzheimer's disease

Background

Neuroinflammation is a principal element in Alzheimer’s disease (AD) pathogenesis, so anti-inflammation may be a promising therapeutic strategy. Forsythoside B (FTS•B), a phenylethanoid glycoside isolated from Forsythiae fructus, has been reported to exert anti-inflammatory effects. However, no studies have reported whether the anti-inflammatory properties of FTS•B have a neuroprotective effect in AD. In the present study, these effects of FTS•B were investigated using amyloid precursor protein/presenilin 1 (APP/PS1) mice, BV-2 cells, and HT22 cells.

Methods

APP/PS1 mice were administered FTS•B intragastrically for 36 days. Behavioral tests were then carried out to examine cognitive functions, including the Morris water maze, Y maze, and open field experiment. Immunohistochemistry was used to analyze the deposition of amyloid-beta (Aβ), the phosphorylation of tau protein, and the levels of 4-hydroxynonenal, glial fibrillary acidic protein, and ionized calcium-binding adapter molecule 1 in the hippocampus. Proteins that showed marked changes in levels related to neuroinflammation were identified using proteomics and verified using enzyme-linked immunosorbent assay and western blot. BV-2 and HT22 cells were also used to confirm the anti-neuroinflammatory effects of FTS•B.

Results

In APP/PS1 mice, FTS•B counteracted cognitive decline, ameliorated the deposition of Aβ and the phosphorylation of tau protein, and attenuated the activation of microglia and astrocytes in the cortex and hippocampus. FTS•B affected vital signaling, particularly by decreasing the activation of JNK-interacting protein 3/C-Jun NH2-terminal kinase and suppressing WD-repeat and FYVE-domain-containing protein 1/toll-like receptor 3 (WDFY1/TLR3), further suppressing the activation of nuclear factor-κB (NF-κB) signaling. In BV-2 and HT22 cells, FTS•B prevented lipopolysaccharide-induced neuroinflammation and reduced the microglia-mediated neurotoxicity.

Conclusions

FTS•B effectively counteracted cognitive decline by regulating neuroinflammation via NF-κB signaling in APP/PS1 mice, providing preliminary experimental evidence that FTS•B is a promising therapeutic agent in AD treatment.

Isoparvifuran isolated from Dalbergia odorifera attenuates H2O2-induced senescence of BJ cells through SIRT1 activation and AKT/mTOR pathway inhibition

Isoparvifuran is a benzofuran compound isolated from the heartwood of Dalbergia odorifera. Related research reported that isoparvifuran has antioxidant property. However, it is unclear whether isoparvifuran has anti-aging effects. In this research, we established an aging model, hydrogen peroxide (H₂O₂)-induced BJ cell senescence, to explore the protective effect of isoparvifuran on cell senescence and its related mechanisms. Our results revealed that isoparvifuran obviously attenuated H₂O₂-induced cell senescence, increased the cell proliferation rate,and reversed senescence-associated molecular markers expression such as cyclin D1, pRb, caveolin-1, ace-p53, p21 and p16. Moreover, isoparvifuran dose and time dependently increased the expression level of Sirtuin 1 (SIRT1) in BJ cells. The inhibition of SIRT1 obviously reversed the reduction of SA-β-gal activity and the alteration of senescence-associated molecular markers induced by isoparvifuran. Additionally, isoparvifuran also inhibited H₂O₂-induced AKT and S6 phosphorylation and increase of SA-β-gal activity. In summary, isoparvifuran protects BJ cells from H₂O₂-induced premature senescence, the anti-senescence effect of isoparvifuran is associated with the activation of SIRT1 and the suppression of AKT/mTOR signaling pathway.

Fatty Acids, Tocopherols, and Phytosterol Composition of Seed Oil and Phenolic Compounds and Antioxidant Activity of Fresh Seeds from Three Dalbergia Species Grown in Vietnam

This research aimed to investigate the chemical composition of seed oils extracted from three Vietnamese Dalbergia species (D. tonkinensis, D. mammosa, and D. entadoides). The fatty acid profiles and contents of tocopherols and sterols of the seed oils, and total phenolic compounds extracted from the fresh seeds were characterized using different methods. Among the examined samples, D. tonkinensis seed oils showed high contents of linoleic acid (64.7%), whereas in D. mammosa, oleic acid (51.2%) was predominant. In addition, α- and γ-tocopherol and β-sitosterol were major ingredients in the seed oils, whereas ferulic acid and rosmarinic acid are usually predominant in the seeds of these species. Regarding sterol composition, the D. entadoides seed oil figured for remarkably high content of Δ5,23-stigmastadienol (1735 mg/kg) and Δ7-stigmastenol (1298 mg/kg). In addition, extracts with methanol/water (80:20, v/v) of seeds displayed significant in vitro antioxidant activity which was determined by DPPH free radical scavenging assay.

Allicin alleviates inflammation of diabetic macroangiopathy via the Nrf2 and NF-kB pathway

As diabetic macroangiopathy is becoming increasingly prevalent, it is urgent to explore preventive and therapeutic drugs and study the mechanism. Diabetic mice were induced by intraperitoneal injection of streptozotocin (STZ)for five consecutive days. Diabetic mice were divided into diabetic and allicin groups. After sacrifice, frozen aortic root sections were immunohistochemically stained for nuclear factor erythroid 2-related factor 2 (Nrf2) and inflammation cytokine-tumor necrosis factor α (TNF-α), and the remaining aortic tissues were analyzed by Western blot for the expression of proinflammation genes. In vitro, Nrf2 and inflammatory relative protein expression levels in Human Umbilical Vein Endothelial Cells (HUVECs) were examined. HUVECs proliferation and apoptosis were measured. TNF-α expression was increased in diabetic group compared to that in control group; this effect was alleviated in allicin-treated mice. Inflammation relative protein expression of Vascular Cell Adhesion Molecule 1(VCAM-1), Matrix metalloproteinase 2 (MMP-2), Inducible Nitric Oxide Synthase (iNOS), and monocyte chemotactic protein 1 (MCP-1) was higher in the diabetic group than in the control group; however, allicin treatment inhibited these diabetes-induced increase. In vitro, allicin treatment reversed the hyperglycemia-induced reduction in proliferation, and decreased the apoptosis induced by high glucose. Inflammation relative protein expression was consistent with that in vivo. Additionally, the expression of nuclear factor kappa-B (NF-κB)and Nrf2 was increased in both DM mice and HUVECs; allicin treatment induced a significant reduction in NF-κB level and improvement in Nrf2 level. Allicin alleviates inflammation caused by diabetic macroangiopathy, and the mechanism may occur via increasing Nrf2 and decreasing NF-κB.

Transcriptional activation of antioxidant gene expression by Nrf2 protects against mitochondrial dysfunction and neuronal death associated with acute and chronic neurodegeneration

Mitochondria are both a primary source of reactive oxygen species (ROS) and a sensitive target of oxidative stress; damage to mitochondria can result in bioenergetic dysfunction and both necrotic and apoptotic cell death. These relationships between mitochondria and cell death are particularly strong in both acute and chronic neurodegenerative disorders. ROS levels are affected by both the production of superoxide and its toxic metabolites and by antioxidant defense mechanisms. Mitochondrial antioxidant activities include superoxide dismutase 2, glutathione peroxidase and reductase, and intramitochondrial glutathione. When intracellular conditions disrupt the homeostatic balance between ROS production and detoxification, a net increase in ROS and an oxidized shift in cellular redox state ensues. Cells respond to this imbalance by increasing the expression of genes that code for proteins that protect against oxidative stress and inhibit cytotoxic oxidation of proteins, DNA, and lipids. If, however, the genomic response to mitochondrial oxidative stress is insufficient to maintain homeostasis, mitochondrial bioenergetic dysfunction and release of pro-apoptotic mitochondrial proteins into the cytosol initiate a variety of cell death pathways, ultimately resulting in potentially lethal damage to vital organs, including the brain. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a translational activating protein that enters the nucleus in response to oxidative stress, resulting in increased expression of numerous cytoprotective genes, including genes coding for mitochondrial and non-mitochondrial antioxidant proteins. Many experimental and some FDA-approved drugs promote this process. Since mitochondria are targets of ROS, it follows that protection against mitochondrial oxidative stress by the Nrf2 pathway of gene expression contributes to neuroprotection by these drugs. This document reviews the evidence that Nrf2 activation increases mitochondrial antioxidants, thereby protecting mitochondria from dysfunction and protecting neural cells from damage and death. New experimental results are provided demonstrating that post-ischemic administration of the Nrf2 activator sulforaphane protects against hippocampal neuronal death and neurologic injury in a clinically-relevant animal model of cardiac arrest and resuscitation.

Dalbergia odorifera: A review of its traditional uses, phytochemistry, pharmacology, and quality control

ETHNOPHARMACOLOGICAL RELEVANCE

Dalbergia odorifera, a traditional herbal medicine, has long been used in China for dissipating blood stasis, regulating the flow of qi, and relieving pain.

AIM OF THIS REVIEW

This review aims to provide comprehensive and up-to-date information about the traditional uses, phytochemistry, pharmacology, and quality control of D. odorifera. Additionally, perspectives for possible future investigations on D. odorifera are also discussed.

MATERIALS AND METHODS

Information on D. odorifera was obtained from a library database and electronic searches (e.g., Elsevier, Springer, ScienceDirect, Wiley, Web of Science, PubMed, Google Scholar, China Knowledge Resource Integrated).

RESULTS

According to classical Chinese herbal texts and the Chinese Pharmacopoeia, D. odorifera promotes blood circulation, relieves pain, and eliminates blood stasis, and it can be used to treat cardio-cerebrovascular diseases in traditional Chinese medicine prescriptions. The chemical constituents of D. odorifera have been well studied, with approximately 175 metabolites having been identified, including flavonoids, phenols, arylbenzofurans, and quinones. The species also contains well-studied volatile oil. Its flavonoids and volatile oil are generally considered to be essential for its pharmacological activity. Modern pharmacology research has confirmed that isolated components and crude extracts of D. odorifera possess wide-ranging pharmacological effects, including anti-inflammatory, anti-angina, anti-oxidative, and other activities. Additionally, there are few quality control studies on D. odorifera.

CONCLUSIONS

To date, significant progress has been made in D. odorifera phytochemistry and pharmacology. Thus, modern pharmacological research has provided some evidence for local or traditional uses. D. odorifera also showed therapeutic potential in cardiovascular and coronary heart diseases. However, the present findings are insufficient to explain its mechanisms of action. Additionally, the mechanism of heartwood formation, artificial induction technology for heartwood production, and quality control of D. odorifera require further detailed research.

An Aspidosperma-type alkaloid dimer from Tabernaemontana bovina as a candidate for the inhibition of microglial activation

As a representative of twelve undescribed Aspidosperma-type alkaloid dimers, tabernaemontine F (6) inhibited microglial activation by blocking P38 MAPK activation, revealing a potential candidate for chronic neurodegenerative diseases.

MG53 attenuates lipopolysaccharide-induced neurotoxicity and neuroinflammation via inhibiting TLR4/NF-κB pathway in vitro and in vivo

Neuroinflammation plays important roles in the pathogenesis and development of neurodegenerative disorders. Lipopolysaccharide (LPS) induces neuroinflammation and causes neurotoxicity, which results in cell damage or memory impairment in different cells and animals. In the present study, we investigated the neuroprotective effects of MG53, a member of the TRIM family proteins, against LPS-induced neuroinflammation and neurotoxicity in vitro and in vivo. MG53 significantly protected HT22 cells against LPS-induced cell apoptosis and cell cycle arrest by inhibiting TNF-α, IL-6 and IL-1β expression. In addition, MG53 ameliorated LPS-induced memory impairment and neuronal cell death in mice. Interestingly, MG53 significantly promoted newborn cell survival, improved neurogenesis, and mitigated neuroinflammation evidenced by lower production of IL-1β and IL-6, less activation of microglia in the hippocampus of LPS treated mice. Further studies demonstrated that MG53 significantly inhibited TLR4 expression and nuclear factor-κB (NF-κB) phosphorylation in LPS treated HT22 cells and mice. Taken together, our results suggested that MG53 attenuated LPS-induced neurotoxicity and neuroinflammation partly by inhibiting TLR4/NF-κB pathway in vitro and in vivo.

Nrf2 signaling and inflammation are key events in physical plasma-spurred wound healing

Wound healing is strongly associated with the presence of a balanced content of reactive species in which oxygen-dependent, redox-sensitive signaling represents an essential step in the healing cascade. Numerous studies have demonstrated that cold physical plasma supports wound healing due to its ability to deliver a beneficial mixture of reactive species directly to the cells.

Methods: We described a preclinical proof-of-principle-concept of cold plasma use in a dermal, full-thickness wound model in immunocompetent SKH1 mice. Quantitative PCR, Western blot analysis, immunohistochemistry and immunofluorescence were perfomed to evaluate the expression and cellular translocation of essential targets of Nrf2 and p53 signaling as well as immunomodulatory and angiogenetic factors. Apoptosis and proliferation were detected using TUNEL assay and Ki67 staining, respectively. Cytokine levels in serum were measured using bead-based multiplex cytokine analysis. Epidermal keratinocytes and dermal fibroblasts were isolated from mouse skin to perform functional knockdown experiments. Intravital fluorescence analysis was used to illustrate and quantified microvascular features.

Results: Plasma exerted significant effects on wound healing in mice, including the promotion of granulation and reepithelialization as a consequence of the migration of skin cells, the balance of antioxidant and inflammatory response, and the early induction of macrophage and neutrophil recruitment to the wound sites. Moreover, through an early and local plasma-induced p53 inhibition with a concomitant stimulation of proliferation, the upregulation of angiogenetic factors, and an increased outgrowth of new vessels, our findings explain why dermal skin repair is accelerated. The cellular redox homeostasis was maintained and cells were defended from damage by a strong modulation of the nuclear E2-related factor (Nrf2) pathway and redox-sensitive p53 signaling.

Conclusions: Although acute wound healing is non-problematic, the pathways highlighted that mainly the activation of Nrf2 signaling is a promising strategy for the clinical use of cold plasma in chronic wound healing.

A Review on the Medicinal Plant Dalbergia odorifera Species: Phytochemistry and Biological Activity

The crucial medicinal plant Dalbergia odorifera T. Chen species belongs to genus Dalbergia, with interesting secondary metabolites, consisting of main classes of flavonoid, phenol, and sesquiterpene derivatives, as well as several arylbenzofurans, quinones, and fatty acids. Biological studies were carried out on extracts, fractions, and compounds from this species involved in cytotoxic assays; antibacterial, antioxidative, anti-inflammatory, antithrombotic, antiplatelet, antiosteosarcoma, antiosteoporosis, antiangiogenesis, and prostaglandin biosynthetic enzyme inhibition activities; vasorelaxant activities; alpha-glucosidase inhibitory activities; and many other effects. In terms of the valuable resources for natural new drugs development, D. odorifera species are widely used as medicinal drugs in many countries for treatment of cardiovascular diseases, cancer, diabetes, blood disorders, ischemia, swelling, necrosis, or rheumatic pain. Although natural products from this plant have been increasingly playing an important role in drug discovery programs, there is no supportive evidence to provide a general insight into phytochemical studies on D. odorifera species and biological activities of extracts, fractions, and isolated compounds. To a certain extent, this review deals with an overview of almost naturally occurring compounds from this species, along with extensive coverage of their biological evaluations.

Induction of Cell Death by Betulinic Acid through Induction of Apoptosis and Inhibition of Autophagic Flux in Microglia BV-2 Cells

Betulinic acid (BA), a natural pentacyclic triterpene found in many medicinal plants is known to have various biological activity including tumor suppression and anti-inflammatory effects. In this study, the cell-death induction effect of BA was investigated in BV-2 microglia cells. BA was cytotoxic to BV-2 cells with IC₅₀ of approximately 2.0 μM. Treatment of BA resulted in a dose-dependent chromosomal DNA degradation, suggesting that these cells underwent apoptosis. Flow cytometric analysis further confirmed that BA-treated BV-2 cells showed hypodiploid DNA content. BA treatment triggered apoptosis by decreasing Bcl-2 levels, activation of capase-3 protease and cleavage of PARP. In addition, BA treatment induced the accumulation of p62 and the increase in conversion of LC3-I to LC3-II, which are important autophagic flux monitoring markers. The increase in LC3-II indicates that BA treatment induced autophagosome formation, however, accumulation of p62 represents that the downstream autophagy pathway is blocked. It is demonstrated that BA induced cell death of BV-2 cells by inducing apoptosis and inhibiting autophagic flux. These data may provide important new information towards understanding the mechanisms by which BA induce cell death in microglia BV-2 cells.

Aryl benzofuran derivatives from the stem bark of Calpocalyx dinklagei attenuate inflammation

Calpocalyx dinklagei Harms (Fabaceae) is a tropical medicinal tree, which is indigenous to Western Africa. A phytochemical study of this local plant species from its stem bark has led to the isolation of two previously undescribed aryl benzofuran derivatives, named dinklagein A and B, together with eight known compounds. Their chemical structures were elucidated by use of extensive spectroscopic methods (IR, HREI-MS and 1D and 2D NMR). Among all isolates, dinklagein A displayed remarkably potent inhibitory activity against the production of nitric oxide (NO) in the lipopolysaccharide (LPS) induced RAW264.7 macrophages. SAR and molecular docking investigations on iNOS and previously undescribed compounds (dinklagein A and B) supported experimental data. Furthermore, dinklagein A dose dependently suppressed the LPS-stimulated iNOS expression at both mRNA and protein level. It also attenuated IL-1β release, mRNA expressions of IL-1β and COX-2 at low doses. These results suggest that dinklagein A can be developed as natural, multi-target agent against several inflammatory diseases.

Dalbergia odorifera extract promotes angiogenesis through upregulation of VEGFRs and PI3K/MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The heart wood of Dalbergia odorifera is a Chinese herbal medicine commonly used for the treatment of various ischemic diseases in Chinese medicine practice.

AIM OF THE STUDY

In this study, therapeutic angiogenesis effects of the Dalbergia odorifera extract (DOE) were investigated on transgenic zebrafish in vivo and human umbilical vein endothelial cells (HUVECs) in vitro.

MATERIALS AND METHODS

The pro-angiogenic effects of DOE on zebrafish were examined by subintestinal vessels (SIVs) sprouting assay and intersegmental vessels (ISVs) injury assay. And the pro-angiogenic effects of DOE on HUVECs were examined by MTT, scratch assay, protein chip and western blot.

RESULTS

In the in vivo studies, we found that DOE was able to dose-dependently promote angiogenesis in zebrafish SIVs area. In addition, DOE could also restore the injury in zebrafish ISVs area and upregulate the reduced mRNA expression of VEGFRs including kdr, kdrl and flt-1 induced by VEGF receptor kinase inhibitor II (VRI). In the in vitro studies, we observed that DOE promoted the proliferation, migration of HUVECs and also restored the injury induced by VRI. Moreover, protein chip and western blot experiments showed the PI3K/MAPK cell proliferation/migration pathway were activated by DOE.

CONCLUSIONS

DOE has a therapeutic effects on angiogenesis, and its mechanism may be related to adjusting the VEGFRs mRNA and activation of PI3K/MAPK signaling pathway. These results suggest a strong potential for Dalbergia odorifera to be developed as an angiogenesis-promoting therapeutic.

4-parvifuran inhibits metastatic and invasive actions through the JAK2/STAT3 pathway in osteosarcoma cells

This study was performed to examine the anticancer and anti-metastatic effects of 4-parvifuran (PVN), a novel flavonoid isolated from the heartwood of Dalbergia odorifera, and to study its underlying signaling pathway in human osteosarcoma cells. In the present study, PVN was found to inhibit cell proliferation in a concentration- and time-dependent manner in the human osteosarcoma cell lines studied (MG-63 and U-2 OS) and induce apoptosis, as evidenced by Annexin V⁺ and TUNEL⁺ cells. Cleaved poly (ADP-ribose) polymerase (PARP) and caspase-3 were up-regulated while anti-apoptotic proteins including Bcl-2, Bcl-xL, and survivin were down-regulated after treatment with PVN. Matrigel cell migration assay, invasion assay, and soft agar assay were used to show that PVN effectively suppressed cell migration and invasion and colony formation in osteosarcoma cells. Protein and mRNA levels of MMP-2 and MMP-9 were reduced by PVN in a concentration-dependent manner. Furthermore, PVN inhibited Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), mitogen-activated protein kinases (MAPKs) including JNK, ERK, p38 kinase, and cAMP response element-binding protein (CREB). Therefore, this is the first study to demonstrate that PVN might be a novel anticancer and anti-metastatic agent for the treatment of osteosarcoma through the inhibition of JAK2/STAT3, MAPKs, and CREB signaling pathways.

Neuroprotective effects of 2,4-dinitrophenol in an acute model of Parkinson's disease

Neurons depend on mitochondria for homeostasis and survival, and thus, mitochondrial dysfunction has been implicated in neurodegenerative diseases, including Parkinson's disease (PD). Increasing evidence indicates the mitochondrial uncoupler, 2,4-dinitrophenol (DNP), protects neurons against neurodegeneration and enhances neural plasticity. Here, the authors evaluated the protective effects of intraperitoneally (i.p.) administered low dose DNP in an acute mouse model of PD. Mice were administered DNP (1 or 5mg/kg) for 12 consecutive days, and then on day 13, MPTP (20mg/kg, i.p.) was administered four times (with 2h intervals between injections) to induce PD. It was found that MPTP-induced motor dysfunction was ameliorated in the DNP-treated mice versus vehicle-treated controls. Additionally, DNP effectively attenuated dopaminergic neuronal loss observed in MPTP treated mice. Moreover, in primary cultured neurons, DNP at 10μM, but not at 100μM, prevented MPP⁺-induced cell death and mitochondrial membrane potential (MMP) reduction. In addition, DNP was observed to cause the nuclear translocation of Nrf2 in primary neurons. Taken together, these findings of the present study suggest that DNP protects dopaminergic neurons against neurodegeneration and maintains MMP integrity in PD by activating adaptive stress responses.

Cudraticusxanthone A isolated from the roots of Cudrania tricuspidata inhibits metastasis and induces apoptosis in breast cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

The roots of Cudrania tricuspidata is a deciduous tree found in Korea, China, and Japan. C. tricuspidata contains an abundance of various minerals, B vitamins, and flavonoids to help prevent diverse cancers. Cudratricusxanthone A (CTXA), a compound isolated from the roots of C. tricuspidata, has potent anti-proliferative, antioxidative, and monoamine oxidase inhibitory effects.

AIM OF THE STUDY

In the present study, cudratricusxanthone A (CTXA) is a xanthone isolated from the bioassay-guided fractionation of the EtOH extract of C. tricuspidata with strong anti-cancer activity in breast cancer cells. The effect of CTXA on cell migration and apoptosis were evaluated in the MCF-7 and MDA-MB-231 human breast carcinoma cell lines.

MATERIALS AND METHODS

Effects of CTXA on phorbol 12-myristate 13-acetate (PMA)-induced MCF-7 and MDA-MB-231 cells. Flow cytometric measurements of CTXA-induced apoptosis in breast cancer cells.

RESULTS

The results show that CTXA gradually reduced viability of the two breast cancer cell lines and induced apoptosis in a concentration-dependent manner. Moreover, CTXA effectively blocked breast cancer cell migration and invasion. CTXA decreased the expression of matrix metalloproteinase-9, extracellular regulated kinases 1 and 2 and phosphorylation of the inhibitor IκBα in the MCF-7 and MDA-MB-231 cell lines.

CONCLUSIONS

Collectively, these results indicate that CTXA possesses anti-cancer activities and provide a basis for developing effective therapeutic agents to inhibit growth and metastasis of breast cancer.

4-Methoxydalbergione suppresses growth and induces apoptosis in human osteosarcoma cells in vitro and in vivo xenograft model through down-regulation of the JAK2/STAT3 pathway

Although the heartwood of Dalbergia odorifera T. Chen (Leguminosae) is an important source of traditional Korean and Chinese medicines, the effects of novel compound methoxydalbergione (4-MD) isolated from Dalbergia odorifera was not reported. Herein, we investigated the effects of the 4-MD in vitro and in vivo against osteosarcoma cells and its molecular mechanisms. 4-MD inhibited the proliferation of osteosarcoma cells and induced apoptosis as evidenced by Annexin V + and TUNEL + cells. This apoptosis was accompanied by upregulation of apoptotic proteins (procaspase-3 and PARP), but downregulation of anti-apoptotic proteins (Bcl-2, Bcl-xL, and Survivin). 4-MD inhibited phosphorylation of JAK2 and STAT3 with the inactivation of mitogen-activated protein kinases (MAPKs) and CREB, and the upregulation of PTEN in osteosarcoma cells. Importantly, 4-MD reduced colony formation in soft agar and inhibited tumor growth in mice xenograft model in association with the reduced expression of PCNA, Ki67, p-STAT3, and Survivin. Taken together, the present study for the first time demonstrates that 4-MD exerts in vitro and in vivo anti-proliferative effects against osteosarcoma cells through the inhibition of the JAK2/STAT3 pathway, and suggest the potential for therapeutic application of 4-MD in the treatment of osteosarcoma.

Nrf2 signaling pathway: Pivotal roles in inflammation

Inflammation is the most common feature of many chronic diseases and complications, while playing critical roles in carcinogenesis. Several studies have demonstrated that Nrf2 contributes to the anti-inflammatory process by orchestrating the recruitment of inflammatory cells and regulating gene expression through the antioxidant response element (ARE). The Keap1 (Kelch-like ECH-associated protein)/Nrf2 (NF-E2 p45-related factor 2)/ARE signaling pathway mainly regulates anti-inflammatory gene expression and inhibits the progression of inflammation. Therefore, the identification of new Nrf2-dependent anti-inflammatory phytochemicals has become a key point in drug discovery. In this review, we discuss the members of the Keap1/Nrf2/ARE signal pathway and its downstream genes, the effects of this pathway on animal models of inflammatory diseases, and crosstalk with the NF-κB pathway. In addition we also discuss about the regulation of NLRP3 inflammasome by Nrf2. Besides this, we summarize the current scenario of the development of anti-inflammatory phytochemicals and others that mediate the Nrf2/ARE signaling pathway.

Low-Dose Homocystine Enhances Proliferation and Migration of Bv2 Microglia Cells

Homocysteine (Hcy) is a non-essential amino acid that is derived from the breakdown of dietary methionine. Hyperhomocysteinemia (HHcy) is an independent risk factor for a variety of chronic diseases, especially neurodegenerative conditions. To better understand the role of HHcy in the pathogenesis of neurodegenerative disorders, we investigated the effect of Hcy on the proliferation and activation of microglia Bv2 cells. Cells were treated with six different Hcy concentrations: 0, 50, 100, 300, 500, and 1000 µM for different time periods (8, 12, 16, 24, and 48 h). The morphology of Bv2 cells was observed, and cell activity and proliferation were detected. Cell migration and secretion of pro-inflammatory cytokines were detected by the scratch wound assay, the transwell assay, and ELISA, respectively. The effect of Hcy on Bv2 proliferation occurred earlier (<24 h, especially 16 h) after treatment with concentrations between 100 and 300 μM, and there was no cytotoxicity to Bv2 cells. Meanwhile, functional assays suggested that Hcy not only promoted Bv2 secretion of the pro-inflammatory cytokines IL-1β, TNF-α, and IL-6, but also enhanced Bv2 migration and invasion, with 100 μM being the most effective concentration. In summary, Bv2 proliferation and activation can be promoted by short-term treatment with low-dose Hcy.

Butein provides neuroprotective and anti-neuroinflammatory effects through Nrf2/ARE-dependent haem oxygenase 1 expression by activating the PI3K/Akt pathway

BACKGROUND AND PURPOSE

Butein, 3,4,2',4'-tetrahydroxychalcone, has various pharmacological effects. However, no study has demonstrated the specific neurobiological mechanisms of the effects of butein in neuronal cells. The present study examined the role of butein as an antioxidative and anti-inflammatory inducer of haem oxygenase 1 (HO1) in mouse hippocampal HT22, BV2 microglial and primary mouse hippocampus neurons.

EXPERIMENTAL APPROACH

We investigated the neuroprotective effects of butein on glutamate-induced HT22 cell and primary mouse hippocampal neuron death and its anti-neuroinflammatory effects on LPS-induced activation of BV2 cells. We elucidated the underlying mechanisms by assessing the involvement of NF-κB, HO1, nuclear factor-E2-related factor 2 (Nrf2) and Akt signalling.

KEY RESULTS

Butein decreased cellular oxidative injury and the production of ROS in glutamate-treated HT22 cells and primary mouse hippocampal neurons. Furthermore, butein suppressed LPS-induced pro-inflammatory enzymes and mediators in BV2 microglia. Butein inhibited IL-6, IL-1β and TNF-α production and mRNA expression. In addition, butein decreased NO and PGE2 production and inducible NOS and COX-2 expression through the NF-κB signalling pathway. Butein up-regulated Nrf2/ARE-mediated HO1 expression through the PI3K/Akt pathway and this was positively associated with its cytoprotective effects and anti-neuroinflammatory actions.

CONCLUSION AND IMPLICATIONS

Our results indicate that butein effectively prevents glutamate-induced oxidative damage and LPS-induced activation and that the induction of HO1 by butein through the PI3K/Akt pathway and Nrf2 activation appears to play a pivotal role in its effects on neuronal cells. Our results provide evidence for the neuroprotective properties of butein.

The herbal extract KCHO-1 exerts a neuroprotective effect by ameliorating oxidative stress via heme oxygenase-1 upregulation

KCHO-1 is a novel product comprised of 30% ethanol extracts obtained from nine medical herbs, which are commonly used in traditional Korean and Chinese medicine. The nine herbs include Curcuma longa, Salvia miltiorrhiza, Gastrodia elata, Chaenomeles sinensis, Polygala tenuifolia, Paeonia japonica, Glycyrrhiza uralensis, Atractylodes japonica and processed Aconitum carmichaeli. Recent studies have reported the beneficial effects of these herbs. The present study aimed to investigate the direct neuroprotective effects of KCHO‑1 on HT22 mouse hippocampal cells, and to determine the possible underlying mechanisms. KCHO‑1 significantly suppressed glutamate‑ and hydrogen peroxide (H2O2)‑induced cell damage, and reactive oxygen species generation. In addition, KCHO‑1 increased the mRNA and protein expression levels of heme oxygenase (HO)‑1. Tin protoporphyrin, which is an inhibitor of HO activity, partially suppressed the effects of KCHO‑1. Furthermore, KCHO‑1 significantly upregulated nuclear factor erythroid‑derived 2‑related factor‑2 (Nrf2) nuclear translocation. Extracellular signal‑regulated kinase (ERK) activation also appeared to be associated with KCHO‑1‑induced HO‑1 expression, since the ERK inhibitor PD98059 suppressed HO‑1 expression and prevented KCHO‑1‑induced cytoprotection. The results of the present study suggested that KCHO‑1 may effectively prevent glutamate‑ or H2O2‑induced oxidative damage via Nrf2/ERK mitogen‑activated protein kinase‑dependent HO‑1 expression. These data suggest that KCHO‑1 may be useful for the treatment of neurodegenerative diseases.

Recent progress on the traditional Chinese medicines that regulate the blood

In traditional Chinese medicine, the herbs that regulate blood play a vital role. Here, nine herbs including Typhae Pollen, Notoginseng Root, Common Bletilla Tuber, India Madder Root and Rhizome, Chinese Arborvitae Twig, Lignum Dalbergiae Oderiferae, Chuanxiong Rhizoma, Corydalis Tuber, and Motherwort Herb were selected and reviewed for their recent studies on anti-tumor, anti-inflammatory and cardiovascular effects. Besides, the analytical methods developed to qualify or quantify the active compounds of the herbs are also summarized.

Potential of butein, a tetrahydroxychalcone to obliterate cancer

BACKGROUND

Despite the major advances made in the field of cancer biology, it still remains one of the most fatal diseases in the world. It is now well established that natural products are safe and efficacious and have high potential in the prevention and treatment of different diseases including cancer. Butein is one such compound which is now found to have anti-cancer properties against various malignancies.

PURPOSE

To thoroughly review the literature available on the anti-cancer properties of butein against different cancers and its molecular targets.

METHODS

A thorough literature search has been done in PubMed for butein, its biological activities especially cancer and its molecular targets.

RESULTS

Our search retrieved several reports on the various biological activities of butein in which around 43 articles reported that butein shows potential anti-proliferative effect against a wide range of neoplasms and the molecular target varies with cancer types. Most often it targets NF-κB and its downstream pathways. In addition, butein induces the expression of genes which mediate the cell death and apoptosis in cancer cells. It also inhibits tumor angiogenesis, invasion and metastasis in prostate, liver and bladder cancers through the inhibition of MMPs, VEGF etc. Moreover, it inhibits the overexpression of several proteins and enzymes such as STAT3, ERK, CXCR4, COX-2, Akt, EGFR, Ras etc. involved in tumorigenesis.

CONCLUSION

Collectively, all these findings suggest the enormous potential and efficacy of butein as a multitargeted chemotherapeutic, chemopreventive and chemosensitizing agent against a wide range of cancers with minimal or no adverse side effects.

2,4,5-Trimethoxyldalbergiquinol promotes osteoblastic differentiation and mineralization via the BMP and Wnt/β-catenin pathway

Dalbergia odorifera has been traditionally used as a medicine to treat many diseases. However, the role of 2,4,5-trimethoxyldalbergiquinol (TMDQ) isolated and extracted from D. odorifera in osteoblast function and the underlying molecular mechanisms remain poorly understood. The aim of this study was to investigate the effects and possible underlying mechanisms of TMDQ on osteoblastic differentiation of primary cultures of mouse osteoblasts as an in vitro assay system. TMDQ stimulated osteoblastic differentiation, as assessed by the alkaline phosphatase (ALP) activity, ALP staining, mineralized nodule formation, and the levels of mRNAs encoding the bone differentiation markers, including ALP, bone sialoprotein (BSP), osteopontin, and osteocalcin. TMDQ upregulated the expression of Bmp2 and Bmp4 genes, and increased the protein level of phospho-Smad1/5/8. Furthermore, TMDQ treatment showed the increased mRNA expression of Wnt ligands, phosphorylation of GSK3, and the expression of β-catenin protein. The TMDQ-induced osteogenic effects were abolished by Wnt inhibitor, Dickkopf-1 (DKK1), and bone morphogenetic protein (BMP) antagonist, noggin. TMDQ-induced runt-related transcription factor 2 (Runx2) expression was attenuatted by noggin and DKK1. These data suggest that TMDQ acts through the activation of BMP, Wnt/β-catenin, and Runx2 signaling to promote osteoblast differentiation, and we demonstrate that TMDQ could be a potential agent for the treatment of bone loss-associated diseases such as osteoporosis.

Acerogenin A from Acer nikoense Maxim Prevents Oxidative Stress-Induced Neuronal Cell Death through Nrf2-Mediated Heme Oxygenase-1 Expression in Mouse Hippocampal HT22 Cell Line

Oxidative cell damage contributes to neuronal degeneration in many central nervous system (CNS) diseases such as Parkinson's disease, Alzheimer's disease, and ischemia. Inducible heme oxygenase (HO)-1 acts against oxidants that are thought to play a key role in the pathogenesis of neuronal diseases. The stem bark of Acer nikoense Maxim (Aceraceae) is indigenous to Japan; it has been used in folk medicine as a treatment of hepatic disorders and eye diseases. Acerogenin A, a natural compound isolated from Japanese folk medicine A. nikoense, showed neuroprotective effects and reactive oxygen species (ROS) reduction on glutamate-induced neurotoxicity by inducing the expression of HO-1 in mouse hippocampal HT22 cells. Furthermore, acerogenin A caused the nuclear accumulation of nuclear factor-E2-related factor 2 (Nrf2) and the activation of the PI3K/AKT signaling pathways. In this study, we demonstrated that acerogenin A effectively prevents glutamate-induced oxidative damage, and HO-1 induction via PI3K/Akt and Nrf2 pathways appears to play a key role in the protection of HT22 cells. Therefore, this study implies that the Nrf2/HO-1 pathway represents a biological target and that acerogenin A might be a candidate for the prevention of neurodegeneration.

Three new phenolic compounds from Dalbergia odorifera

Three new phenolic compounds (1-3) were isolated from the heartwood of Dalbergia odorifera T. Chen. (Leguminosae). Their structures were established based on spectroscopic methods including 1D and 2D NMR (HSQC, COSY, HMBC and ROESY). Compound 2 exhibited cytotoxicity against BEL-7402 tumor cell lines.

Cudarflavone B provides neuroprotection against glutamate-induced mouse hippocampal HT22 cell damage through the Nrf2 and PI3K/Akt signaling pathways

Oxidative cell damage contributes to neuronal degeneration in many central nervous system (CNS) diseases such as Alzheimer's disease, Parkinson's disease, and ischemia. Nrf2 signaling-mediated heme oxygenase (HO)-1 expression acts against oxidants that are thought to play a key role in the pathogenesis of neuronal diseases. Cudraflavone B is a prenylated flavone isolated from C. tricuspidata which has shown anti-proliferative activity, mouse brain monoamine oxidase (MAO) inhibitory effects, apoptotic actions in human gastric carcinoma cells and mouse melanoma cells, and hepatoprotective activity. In this study, cudraflavone B showed neuroprotective effects and reactive oxygen species (ROS) inhibition against glutamate-induced neurotoxicity by inducing the expression of HO-1 in mouse hippocampal HT22 cells. Furthermore, cudraflavone B caused the nuclear accumulation of nuclear factor-E2-related factor 2 (Nrf2) and increased the promoter activity of antioxidant response elements (ARE) in mouse hippocampal HT22 cells. In addition, we found that the Nrf2-midiated HO-1 expression by cudraflavone B is involved in the cell protective response and ROS reductions, and cudraflavone B-induced expression of HO-1 was mediated through the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in HT22 cells. Our results demonstrated the potential application of naturally occurring cudraflavone B as a therapeutic agent from neurodegenerative disease.