Oridonin, A natural diterpenoid, protected NGF-differentiated PC12 cells against MPP+- and kainic acid-induced injury

Geraniol Ameliorates Pentylenetetrazol-Induced Epilepsy, Neuroinflammation, and Oxidative Stress via Modulating the GABAergic Tract: In vitro and in vivo studies

Introduction

Geraniol (Ger), a monoterpene, is a common constituent of several essential oils. This study explored the anticonvulsant effect of Ger in-vitro using nerve growth factor (NGF) prompted PC12 cell injured by Glutamate (Glu) and in-vivo using Pentylenetetrazole (PTZ)-induced kindling through the GABAergic pathway.

Materials

To assess the effect of Ger on NGF prompted PC12 cells injured by Glu, Ger at concentrations of 25, 50, 100, 200 and 400 μg/mL was used. GABA, 5-HT, IL-1β, IL-4, and TNF-α levels and the gene expressions of GABAA-Rα1, NMDAR1, GAD 65, GAD 67, GAT 1 and GAT 3 were measured in NGF-induced PC12 cells treated with Ger (100, and 200 μg/mL). Mice were randomly separated into five groups. Normal and PTZ groups in which mice were injected with saline or PTZ, respectively. PTZ + Ger 100, PTZ + Ger 200 and PTZ + SV groups in which mice orally administered Ger or sodium valproate (SV), respectively, then injected with PTZ.

Results

Ger up to 400 μg/mL did not display any toxicity or injury in PC12 cells. Ger (100 to 200 μg/mL) reduced the injury induced by Glu, increased the gene expression of GABAA-Rα1, GAD65 and GAD67 and decreased GAT 1, GAT 3 and NMDAR1 expression in NGF-induced PC12 cells damaged by Glu. Ger (100 to 200 μg/mL) increased GABA and reduced TNF-α, IL-4 and IL-1β levels in NGF-induced PC12 cells injured by Glu. As for the in-vivo results, Ger increased GABA, GAD, GAT 1 and 3 and lowered GABA T. Ger mitigated MDA, NO, IL-1β, IL-6, TNF-α and IFN-γ, GFAP, caspase-3, and -9 levels and Bax gene expression and escalated GSH, SOD, catalase, BDNF and Bcl2 gene expression.

Conclusion

Ger reduced the oxidative stress status, neuroinflammation and apoptosis and activated GABAergic neurotransmission, which might clarify its anticonvulsant. Ger protects animals against PTZ prompted kindling as established by the enhancement in short term as well as long-term memory. Ger mitigated the injury induced by Glu in NGF prompted PC12 cell.

Oridonin exerts anticonvulsant profile and neuroprotective activity in epileptic mice by inhibiting NLRP3-mediated pyroptosis

BACKGROUND

Epilepsy is a chronic disabling disease poorly controlled by available antiseizure medications. Oridonin, a bioactive alkaloid with anti-inflammatory properties and neuroprotective effects, can inhibit the increased excitability of neurons caused by glutamate accumulation at the cellular level. However, whether oridonin affects neuronal excitability and whether it has antiepileptic potential has not been reported in animal models or clinical studies.

METHOD

Pentylenetetrazol was injected into mice to create a model of chronic epilepsy. Seizure severity was assessed using the Racine scale, and the duration and latency of seizures were observed. Abnormal neuronal discharge was detected using electroencephalography, and neuronal excitability was assessed using calcium imaging. Damage to hippocampal neurons was evaluated using Hematoxylin-Eosin and Nissl staining. The expression of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome and other pyroptosis-related proteins was determined using western blotting and immunofluorescence. A neuronal pyroptosis model was established using the supernatant of BV2 cells treated with lipopolysaccharide and adenosine triphosphate to stimulate hippocampal neurons.

RESULTS

Oridonin (1 and 5 mg/kg) reduced neuronal damage, increased the latency of seizures, and shortened the duration of fully kindled seizures in chronic epilepsy model mice. Oridonin decreased abnormal discharge during epileptic episodes and suppressed increased neuronal excitability. In vitro experiments showed that oridonin alleviated pyroptosis in hippocampal HT22 neurons.

CONCLUSION

Oridonin exerts neuroprotective effects by inhibiting pyroptosis through the NLRP3/caspase-1 pathway in chronic epilepsy model mice. It also reduces pyroptosis in hippocampal neurons in vitro, suggesting its potential as a therapy for epilepsy.

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

Protein-protein interactions and related inhibitors involved in the NLRP3 inflammasome pathway

NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) receptor serves as the central node of immune sensing in the innate immune system, and plays an important role in the initiation and progression of chronic diseases. Cryo-electron microscopy (cryo-EM) has provided insights into the conformation of various oligomers within the NLRP3 activation pathway, significantly advancing our understanding of the mechanisms underlying NLRP3 inflammasome activation. Despite the extensive network of protein-protein interactions (PPIs) involved in the assembly and activation of NLRP3 inflammasome, the utilization of protein-protein interactions has been relatively overlooked in the development of NLRP3 inhibitors. This review focuses on summarizing PPIs within the NLRP3 inflammasome activation pathway and small molecule inhibitors capable of interfering with PPIs to counteract the NLRP3 overactivation. Small molecule NLRP3 inhibitors have been gained significant attention owing to their remarkable efficacy, excellent safety profiles, and unique mechanisms of action.

Na+,K+-ATPase and Cardiotonic Steroids in Models of Dopaminergic System Pathologies

In recent years, enough evidence has accumulated to assert that cardiotonic steroids, Na⁺,K⁺-ATPase ligands, play an integral role in the physiological and pathophysiological processes in the body. However, little is known about the function of these compounds in the central nervous system. Endogenous cardiotonic steroids are involved in the pathogenesis of affective disorders, including depression and bipolar disorder, which are linked to dopaminergic system dysfunction. Animal models have shown that the cardiotonic steroid ouabain induces mania-like behavior through dopamine-dependent intracellular signaling pathways. In addition, mutations in the alpha subunit of Na⁺,K⁺-ATPase lead to the development of neurological pathologies. Evidence from animal models confirms the neurological consequences of mutations in the Na⁺,K⁺-ATPase alpha subunit. This review is dedicated to discussing the role of cardiotonic steroids and Na⁺,K⁺-ATPase in dopaminergic system pathologies-both the evidence supporting their involvement and potential pathways along which they may exert their effects are evaluated. Since there is an association between affective disorders accompanied by functional alterations in the dopaminergic system and neurological disorders such as Parkinson's disease, we extend our discussion to the role of Na⁺,K⁺-ATPase and cardiotonic steroids in neurodegenerative diseases as well.

Recent advances in oridonin derivatives with anticancer activity

Cancer is a leading cause of mortality responsible for an estimated 10 million deaths worldwide in 2020, and its incidence has been rapidly growing over the last decades. Population growth and aging, as well as high systemic toxicity and chemoresistance associated with conventional anticancer therapies reflect these high levels of incidence and mortality. Thus, efforts have been made to search for novel anticancer drugs with fewer side effects and greater therapeutic effectiveness. Nature continues to be the main source of biologically active lead compounds, and diterpenoids are considered one of the most important families since many have been reported to possess anticancer properties. Oridonin is an ent-kaurane tetracyclic diterpenoid isolated from Rabdosia rubescens and has been a target of extensive research over the last few years. It displays a broad range of biological effects including neuroprotective, anti-inflammatory, and anticancer activity against a variety of tumor cells. Several structural modifications on the oridonin and biological evaluation of its derivatives have been performed, creating a library of compounds with improved pharmacological activities. This mini-review aims to highlight the recent advances in oridonin derivatives as potential anticancer drugs, while succinctly exploring their proposed mechanisms of action. To wind up, future research perspectives in this field are also disclosed.

Toll-like receptors and NLRP3 inflammasome-dependent pathways in Parkinson's disease: mechanisms and therapeutic implications

Parkinson's disease (PD) is a chronic progressive neurodegenerative disorder characterized by motor and non-motor disturbances as a result of a complex and not fully understood pathogenesis, probably including neuroinflammation, oxidative stress, and formation of alpha-synuclein (α-syn) aggregates. As age is the main risk factor for several neurodegenerative disorders including PD, progressive aging of the immune system leading to inflammaging and immunosenescence may contribute to neuroinflammation leading to PD onset and progression; abnormal α-syn aggregation in the context of immune dysfunction may favor activation of nucleotide-binding oligomerization domain-like receptor (NOD) family pyrin domain containing 3 (NLRP3) inflammasome within microglial cells through interaction with toll-like receptors (TLRs). This process would further lead to activation of Caspase (Cas)-1, and increased production of pro-inflammatory cytokines (PC), with subsequent impairment of mitochondria and damage to dopaminergic neurons. All these phenomena are mediated by the translocation of nuclear factor kappa-B (NF-κB) and enhanced by reactive oxygen species (ROS). To date, drugs to treat PD are mainly aimed at relieving clinical symptoms and there are no disease-modifying options to reverse or stop disease progression. This review outlines the role of the TLR/NLRP3/Cas-1 pathway in PD-related immune dysfunction, also focusing on specific therapeutic options that might be used since the early stages of the disease to counteract neuroinflammation and immune dysfunction.

Oridonin relieves depressive-like behaviors by inhibiting neuroinflammation and autophagy impairment in rats subjected to chronic unpredictable mild stress

Major depressive disorder (MDD) is a severe life-threatening disorder with increasing prevalence. However, the mechanistic interplay between depression, neuroinflammation, and autophagy is yet to be demonstrated. This study investigated the effect of Oridonin on CUMS-induced depression, neuroinflammation, and autophagy impairment. Male 4-week-old Sprague-Dawley rats were subjected to chronic unpredictable mild stress (CUMS), some of which were injected with Oridonin, fluoxetine (FLX), or their combination at different durations of CUMS. CUMS significantly increased the levels of cytokines (IL-1β, IL-18, and caspase-1), reduced autophagy-related protein levels (Beclin-1, p62, Atg5, and LC3B), and caused microglia cells activation. Oridonin prevented and reversed the depressive-like behavior. Furthermore, it has a stronger and longer-lasting antidepressant effect than FLX. And the antidepressant effect of Oridonin in combination with fluoxetine was greater than that of high-dose fluoxetine alone. In addition, Oridonin significantly normalized autophagy-related protein levels, and reduced levels of cytokines by blocking the interaction between NLRP3 and NEK7. Similarly, Oridonin abolished levels of cytokines and reversed autophagy impairment in LPS-activated BV2 cells. All these results supported our hypothesis that Oridonin possesses potent anti-depressive action, which might be mediated via inhibition of neuroinflammation and autophagy impairment by blocking the interaction between NLRP3 and NEK7.

Targeting autophagy and neuroinflammation pathways with plant-derived natural compounds as potential antidepressant agents

Major depressive disorder (MDD) is a life-threatening disease that presents several characteristics. The pathogenesis of depression still remains poorly understood. Moreover, the mechanistic interactions of natural components in treating depression to target autophagy and neuroinflammation are yet to be evaluated. This study overviewed the effects of plant-derived natural components in regulating critical pathways, particularly neuroinflammation and autophagy, associated with depression. A list of natural components, including luteolin, apigenin, hyperforin, resveratrol, salvianolic acid b, isoliquiritin, nobiletin, andrographolide, and oridonin, have been investigated. All peer-reviewed journal articles were searched by Scopus, MEDLINE, PubMed, Web of Science, and Google Scholar using the appropriated keywords, including depression, neuroinflammation, autophagy, plant, natural components, etc. The neuroinflammation and autophagy dysfunction are critically associated with the pathophysiology of depression. Natural components with higher efficiency and lower complications can be used for targeting neuroinflammation and autophagy. These components with different doses showed the beneficial antidepressant properties in rodents. These can modulate autophagy markers, mainly AMPK, LC3II/LC3I ratio, Beclin-1. Moreover, they can regulate the NLRP3 inflammasome, resulting in the suppression of proinflammatory cytokines (e.g., IL-1β and IL-18). Future in vitro and in vivo studies are required to develop novel therapeutic approaches based on plant-derived active components to treat MDD.

Oridonin Relieves Angiotensin II-Induced Cardiac Remodeling via Inhibiting GSDMD-Mediated Inflammation

Myocardial remodeling is one of the main lesions in the late stage of chronic heart failure and seriously affects the prognosis of patients. Continuous activation of the renin-angiotensin-aldosterone system (RAAS) contributes to the development of myocardial remodeling greatly, and angiotensin II (Ang II), its main constituent, can directly lead to cardiac remodeling through an inflammatory response and oxidative stress. Since Ang II-induced myocardial remodeling is closely related to inflammation, we tried to explore whether the anti-inflammatory drug oridonin (Ori) can reverse this process and its possible mechanism. Our study investigated that hypertrophy and fibrosis can be induced after being treated with Ang II in cardiomyocytes (H9c2 cells and primary rat cardiomyocytes) and C57BL/6J mice. The anti-inflammatory drug oridonin could effectively attenuate the degree of cardiac remodeling both in vivo and vitro by inhibiting GSDMD, a key protein of intracellular inflammation which can further activate kinds of inflammation factors such as IL-1β and IL-18. We illustrated that oridonin reversed cardiac remodeling by inhibiting the process of inflammatory signaling through GSDMD. After inhibiting the expression of GSDMD in cardiomyocytes by siRNA, it was found that Ang II-induced hypertrophy was attenuated. These results suggest that oridonin is proved to be a potential protective drug against GSDMD-mediated inflammation and myocardial remodeling.

MPP+-Induced Changes in Cellular Impedance as a Measure for Organic Cation Transporter (SLC22A1-3) Activity and Inhibition

The organic cation transporters OCT1-3 (SLC22A1-3) facilitate the transport of cationic endo- and xenobiotics and are important mediators of drug distribution and elimination. Their polyspecific nature makes OCTs highly susceptible to drug-drug interactions (DDIs). Currently, screening of OCT inhibitors depends on uptake assays that require labeled substrates to detect transport activity. However, these uptake assays have several limitations. Hence, there is a need to develop novel assays to study OCT activity in a physiological relevant environment without the need to label the substrate. Here, a label-free impedance-based transport assay is established that detects OCT-mediated transport activity and inhibition utilizing the neurotoxin MPP⁺. Uptake of MPP⁺ by OCTs induced concentration-dependent changes in cellular impedance that were inhibited by decynium-22, corticosterone, and Tyrosine Kinase inhibitors. OCT-mediated MPP⁺ transport activity and inhibition were quantified on both OCT1-3 overexpressing cells and HeLa cells endogenously expressing OCT3. Moreover, the method presented here is a valuable tool to identify novel inhibitors and potential DDI partners for MPP⁺ transporting solute carrier proteins (SLCs) in general.

Sesquiterpenoids and 2-(2-Phenylethyl)chromone Derivatives from the Resinous Heartwood of Aquilaria sinensis

One novel spirolactone, aquilarisinolide (1), three new sesquiterpenoids, (2R,4S,5R,7R)-2-hydroxyeremophila-9,11-dien-8-one (2), (1R,4S,5S,7R,11R)-13-hydroxyepidaphnauran-9-en-8-one (3), and (4R,5S,7R,8S,10S,13R)-8,13-dihydroxyrotunda-1,11-dien-3-one (4), together with 13 known compounds (5-17) were isolated from the resinous heartwood of Aquilaria sinensis (Thymelaeaceae). The structures of the new compounds were elucidated based on the analysis of NMR and MS data and theoretical calculations their ECD spectra. The isolated compounds were evaluated for their protective activities against PC12 cell injury induced by corticosterone (CORT) and 1-methyl-4-phenylpyridine ion (MPP+), as well as inhibitory activities against BACE1. Compound 4, 5,6-dihydroxy-2-(2-phenylethyl)chromone (5), daphnauranol B (7), 6-methoxy-2-[2-(3-methyoxyphenyl)ethyl]chromone (10), isoagarotetrol (14), and 1-hydroxy-1,5-diphenylpentan-3-one (16) showed significant protective effects on CORT-induced injury in PC12 cells at a concentration of 20 μM (P < 0.001). Isoagarotetrol (14) showed a significant protective effect on MPP+-induced injury in PC12 cells at a concentration of 20 μM (P < 0.001), while compound 4 showed a moderate activity (P < 0.01). The BACE1-inhibitory activities of all tested compounds were very weak with less than 30% inhibition at a concentration of 20 μM.

Platelet-derived growth factor (PDGF)-BB protects dopaminergic neurons via activation of Akt/ERK/CREB pathways to upregulate tyrosine hydroxylase

Aims

The neurotropic growth factor PDGF‐BB was shown to have vital neurorestorative functions in various animal models of Parkinson's disease (PD). Previous studies indicated that the regenerative property of PDGF‐BB contributes to the increased intensity of tyrosine hydroxylase (TH) fibers in vivo. However, whether PDGF‐BB directly modulates the expression of TH, and the underlying mechanism is still unknown. We will carefully examine this in our current study.

Method

MPTP‐lesion mice received PDGF‐BB treatment via intracerebroventricular (i.c.v) administration, and the expression of TH in different brain regions was assessed by RT‐PCR, Western blot, and immunohistochemistry staining. The molecular mechanisms of PDGF‐BB‐mediated TH upregulation were examined by RT‐PCR, Western blot, ChIP assay, luciferase reporter assay, and immunocytochemistry.

Results

We validated a reversal expression of TH in MPTP‐lesion mice upon i.c.v administration of PDGF‐BB for seven days. Similar effects of PDGF‐BB‐mediated TH upregulation were also observed in MPP⁺‐treated primary neuronal culture and dopaminergic neuronal cell line SH‐SY5Y cells. We next demonstrated that PDGF‐BB rapidly activated the pro‐survival PI3K/Akt and MAPK/ERK signaling pathways, as well as the downstream CREB in SH‐SY5Y cells. We further confirmed the significant induction of p‐CREB in PDGF‐BB‐treated animals in vivo. Using a genetic approach, we demonstrated that the transcription factor CREB is critical for PDGF‐BB‐mediated TH expression. The activation and nucleus translocation of CREB were promoted in PDGF‐BB‐treated SH‐SY5Y cells, and the enrichment of CREB on the promoter region of TH gene was also increased upon PDGF‐BB treatment.

Conclusion

Our data demonstrated that PDGF‐BB directly regulated the expression of TH via activating the downstream Akt/ERK/CREB signaling pathways. Our finding will further support the therapeutic potential of PDGF‐BB in PD, and provide the possibility that targeting PDGF signaling can be harnessed as an adjunctive therapy in PD in the future.

Oridonin: A Review of Its Pharmacology, Pharmacokinetics and Toxicity

Oridonin, as a natural terpenoids found in traditional Chinese herbal medicine Isodon rubescens (Hemsl.) H.Hara, is widely present in numerous Chinese medicine preparations. The purpose of this review focuses on providing the latest and comprehensive information on the pharmacology, pharmacokinetics and toxicity of oridonin, to excavate the therapeutic potential and explore promising ways to balance toxicity and efficacy of this natural compound. Information concerning oridonin was systematically collected from the authoritative internet database of PubMed, Elsevier, Web of Science, Wiley Online Library and Europe PMC applying a combination of keywords involving "pharmacology," "pharmacokinetics," and "toxicology". New evidence shows that oridonin possesses a wide range of pharmacological properties, including anticancer, anti-inflammatory, hepatorenal activities as well as cardioprotective protective activities and so on. Although significant advancement has been witnessed in this field, some basic and intricate issues still exist such as the specific mechanism of oridonin against related diseases not being clear. Moreover, several lines of evidence indicated that oridonin may exhibit adverse effects, even toxicity under specific circumstances, which sparked intense debate and concern about security of oridonin. Based on the current progress, future research directions should emphasize on 1) investigating the interrelationship between concentration and pharmacological effects as well as toxicity, 2) reducing pharmacological toxicity, and 3) modifying the structure of oridonin-one of the pivotal approaches to strengthen pharmacological activity and bioavailability. We hope that this review can provide some inspiration for the research of oridonin in the future.

Next‑generation sequencing analysis reveals that MTH‑3, a novel curcuminoid derivative, suppresses the invasion of MDA‑MB‑231 triple‑negative breast adenocarcinoma cells

Triple‑negative breast cancer (TNBC) behaves aggressively in the invasive and metastatic states. Our research group recently developed a novel curcumin derivative, (1E,3Z,6E)-3-hydroxy-5-oxohepta-1,3,6-triene-1,7-diyl)bis(2‑methoxy-4,1‑phenylene)bis(3-hydroxy2-hydroxymethyl)-2‑methyl propanoate (MTH‑3), and previous studies showed that MTH‑3 inhibits TNBC proliferation and induces apoptosis in vitro and in vivo with a superior bioavailability and absorption than curcumin. In the present study, the effects of MTH‑3 on TNBC cell invasion were examined using various assays and gelatin zymography, and western blot analysis. Treatment with MTH‑3 inhibited MDA‑MB‑231 cell invasion and migration, as shown by Transwell assay, 3D spheroid invasion assay, and wound healing assay. The results of the gelatin zymography experiments revealed that MTH‑3 decreased matrix metalloproteinase‑9 activity. The potential signaling pathways were revealed by next‑generation sequencing analysis, antibody microarray analysis and western blot analysis. In conclusion, the results of the present study show that, MTH‑3 inhibited tumor cell invasion through the MAPK/ERK/AKT signaling pathway and cell cycle regulatory cascade, providing significant information about the potential molecular mechanisms of the effects of MTH‑3 on TNBC.

Oridonin Attenuates the Effects of Chronic Alcohol Consumption Inducing Oxidative, Glycative and Inflammatory Injury in the Mouse Liver

BACKGROUND/AIM

Oridonin (Ori) is a diterpenoid naturally present in medicinal plants with a potential as an antioxidant agent. This study aimed to evaluate the hepatic anti-oxidative, anti-glycative and anti-inflammatory properties of Ori at 0.125 and 0.25% against chronic ethanol intake in mice.

MATERIALS AND METHODS

Mice were divided into five groups: i) normal diet group, ii) Ori group, iii) ethanol diet (Lieber-DeCarli liquid diet with ethanol) group, iv) ethanol diet plus 0.125% Ori and v) ethanol diet plus 0.25% Ori. After 8 weeks of Ori supplementation, blood and liver tissue were used for analyses.

RESULTS

Ethanol increased the production of reactive oxygen species and nitric oxide, decreased glutathione content, and lowered the activity of glutathione peroxide, glutathione reductase and catalase. Ethanol suppressed the hepatic mRNA expression of nuclear factor E2-related factor 2. Ori supplements reversed these changes. Ethanol increased hepatic N^e-(carboxyethymethyl)-lysine (CML) and pentosidine levels, and enhanced aldose reductase (AR) activity and mRNA expression. Ori supplements at only 0.25% decreased CML and pentosidine levels, and lowered the AR activity as well as its mRNA expression. Ethanol increased the hepatic release of tumor necrosis factor-alpha, transforming growth factor-beta1, interleukin (IL)-1beta and IL-6. Histological data showed that ethanol induced necrosis and inflammatory cell infiltration, while Ori supplements alleviated these inflammatory responses. Ethanol up-regulated the hepatic mRNA expression of nuclear factor kappa B, myeloperoxidase and p38. Ori supplements reversed these changes.

CONCLUSIONS

These novel findings suggest that Ori could be used as a potent agent against alcohol-induced hepatotoxicity.

Renoprotective Effect of Oridonin in a Mouse Model of Acute Kidney Injury via Suppression of Macrophage Involved Inflammation

Ischemia-reperfusion injury (IRI) is the major cause of acute kidney injury (AKI). The previous studies demonstrated that Oridonin can protect kidney against IRI-induced AKI, but the underlying molecular mechanism is unclear. In this study, it showed that Oridonin significantly improved kidney damage, and inhibited the expression of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α and MCP-1, as well as macrophage marker F4/80 in kidney and the secretion of inflammatory cytokins in serum of AKI mice in vivo. In addition, Oridonin also effectively reduced the expression and secretion of lipopolysaccharide (LPS)-induced inflammatory factors in macrophage cell line RAW264.7 in vitro. Notably, Oridonin strongly downregulated Mincle and AKT/nuclear factor-kappaB (NF-κB) signaling both in vivo and in vitro, and the results of cellular recovery experiments of overexpression of Mincle in macrophage suggested that Oridonin suppressed inflammatory response of macrophage through inhibiting Mincle, which may be the underlying mechanism of Oridonin improving injury in kidney of AKI mice. In summary, the above results indicated that Oridonin can protect kidney from IRI-induced inflammation and injury by inhibiting the expression of Mincle in macrophage.

Herbal Resources to Combat a Progressive & Degenerative Nervous System Disorder- Parkinson's Disease

Parkinson's disease is one of the most common adult-onset, a chronic disorder involving neurodegeneration, which progressively leads to deprivation of dopaminergic neurons in substantia nigra, causing a subsequent reduction of dopamine levels in the striatum resulting in tremor, myotonia, and dyskinesia. Genetics and environmental factors are believed to be responsible for the onset of Parkinson's disease. The exact pathogenesis of Parkinson's disease is quite complicated and the present anti-Parkinson's disease treatments appear to be clinically insufficient. Comprehensive researches have demonstrated the use of natural products such as ginseng, curcumin, ashwagandha, baicalein, etc. for the symptomatic treatment of this disease. The neuroprotective effects exhibited by these natural products are mainly due to their ability to increase dopamine levels in the striatum, manage oxidative stress, mitochondrial dysfunction, glutathione levels, clear the aggregation of α- synuclein, induce autophagy and decrease the pro-inflammatory cytokines and lipid peroxidation. This paper reviews various natural product studies conducted by scientists to establish the role of natural products (both metabolite extracts as well as pure metabolites) as adjunctive neuroprotective agents.

Oridonin ameliorates insulin resistance partially through inhibition of inflammatory response in rats subjected to chronic unpredictable mild stress

BACKGROUND

Oridonin (Ori) has multiple biological properties, especially anti-inflammatory. However, its effects on chronic unpredictable mild stress (CUMS)-induced insulin resistance are still unclear. In this study, we explored the regulatory role of Ori in CUMS-triggered insulin resistance, and the underlying molecular mechanisms; Methods: SD rats were subjected to CUMS for 4 weeks, some of which were injected with Ori or fluoxetine (FLX) in durations of CUMS. After CUMS procedure, the behavioral and metabolic tests were performed. Elisa, immunofluorescence and western blotting were used to determine the inflammatory response and NLRP3 inflammasome activation. We investigated the interaction between NLRP3 and NEK7 using immunoprecipitation. Finally, we detected the proinflammatory cytokines in Lipopolysaccharide (LPS)-activated RAW264.7 cells treated with Ori; RESULTS: In this study, we found that chronic stress resulted in depressive-like behavior comorbid with insulin resistance. Ori was discovered to ameliorate insulin resistance as well as insulin signaling disturbance in the hippocampus. In addition, CUMS caused the infiltration of macrophages into the islets. And IL-1β, IL-18 and caspase-1 were elevated in pancreases of CUMS rats, which could also be reversed by Ori treatment via reducing the interaction between NLRP3 and NEK7. Furthermore, Ori dose-dependently inhibited the levels of IL-1β and IL-18 in LPS-activated RAW264.7 cells; CONCLUSIONS: All these results supported our hypothesis that Ori possesses potent anti-insulin resistant actions, which is partially correlated with inhibiting infiltration of macrophages into the islets and NLRP3 activation induced by CUMS. Therefore, our results highlighted the protective role of Ori against CUMS-elicited insulin resistance.

Neuroprotective compounds from the resinous heartwood of Aquilaria sinensis

Six undescribed compounds, including three sesquiterpenoids [(4S,5S,7S,8S,11R)-7-hydroxyguai-1(10)-en-8,12-olide, aquilarisinone, and 2Z,7(13),9E-humulatrien-12-ol-5-one], one diphenylpentanone [1-(2-hydroxyphenyl)-5-phenylpentan-3-one], and two 2-(2-phenylethyl)chromones (6-epiagarotetrol and triepoxyhexahydrochromone A), along with 15 known compounds, were isolated from the resinous heartwood of Aquilaria sinensis (Thymelaeaceae). Their structures were determined by mass (MS) and nuclear magnetic resonance (NMR) spectroscopic data. The absolute configuration of (4S,5S,7S,8S,11R)-7-hydroxyguai-1(10)-en-8,12-olide was confirmed by X-ray diffraction analysis, and the configurations of (4S,7S,8S,10R,11R)-7,10-epoxyguai-1(5)-en-8,12-olide, aquilarisinone, 6-epiagarotetrol, and triepoxyhexahydrochromone A were confirmed by electronic circular dichroism (ECD) calculations. The neuroprotective activities of the compounds were evaluated using models of BACE1 inhibition and PC12 cells with corticosterone- and 1-methyl-4-phenylpyridine ion (MPP⁺)-induced damage. At concentrations of 1, 2, and 5 μM, triepoxyhexahydrochromone A, (+)-(7R,10R)-selina-4,11(13)-diene-12,15-dial, (-)-(5R,7R,10R)-12,15-dioxo-α-selinene, and (+)-(1R,4S,5R)-1β-hydroxyeremophila-7(11),9-dien-8-one exerted significant protective effects (p < 0.01) on PC12 cell injury induced by corticosterone, while triepoxyhexahydrochromone A and (-)-(5R,7R,10R)-12,15-dioxo-α-selinene exerted significant protective effects (p < 0.01) on MPP⁺-induced PC12 cell injury at concentrations of 1, 2, and 5 μM. No compounds produced significant inhibitory effects on BACE1, with inhibition rates of less than 20% observed at a concentration of 20 μM.

The transcription factor REST up-regulates tyrosine hydroxylase and antiapoptotic genes and protects dopaminergic neurons against manganese toxicity

Dopaminergic functions are important for various biological activities, and their impairment leads to neurodegeneration, a hallmark of Parkinson's disease (PD). Chronic manganese (Mn) exposure causes the neurological disorder manganism, presenting symptoms similar to those of PD. Emerging evidence has linked the transcription factor RE1-silencing transcription factor (REST) to PD and also Alzheimer's disease. But REST's role in dopaminergic neurons is unclear. Here, we investigated whether REST protects dopaminergic neurons against Mn-induced toxicity and enhances expression of the dopamine-synthesizing enzyme tyrosine hydroxylase (TH). We report that REST binds to RE1 consensus sites in the TH gene promoter, stimulates TH transcription, and increases TH mRNA and protein levels in dopaminergic cells. REST binding to the TH promoter recruited the epigenetic modifier cAMP-response element-binding protein-binding protein/p300 and thereby up-regulated TH expression. REST relieved Mn-induced repression of TH promoter activity, mRNA, and protein levels and also reduced Mn-induced oxidative stress, inflammation, and apoptosis in dopaminergic neurons. REST reduced Mn-induced proinflammatory cytokines, including tumor necrosis factor α, interleukin 1β (IL-1β), IL-6, and interferon γ. Moreover, REST inhibited the Mn-induced proapoptotic proteins Bcl-2-associated X protein (Bax) and death-associated protein 6 (Daxx) and attenuated an Mn-induced decrease in the antiapoptotic proteins Bcl-2 and Bcl-xL. REST also enhanced the expression of antioxidant proteins, including catalase, NF-E2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1). Our findings indicate that REST activates TH expression and thereby protects neurons against Mn-induced toxicity and neurological disorders associated with dopaminergic neurodegeneration.

The Effect of Protein-Rich Extract from Bombyx Batryticatus against Glutamate-Damaged PC12 Cells Via Regulating γ-Aminobutyric Acid Signaling Pathway

Bombyx Batryticatus (BB) is a known traditional Chinese medicine (TCM) utilized to treat convulsions, epilepsy, cough, asthma, headaches, etc. in China for thousands of years. This study is aimed at investigating optimum extraction of protein-rich extracts from BB (BBPs) using response surface methodology (RSM) and exploring the protective effects of BBPs against nerve growth factor (NGF)-induced PC12 cells injured by glutamate (Glu) and their underlying mechanisms. The results indicated optimum process of extraction was as follows: extraction time 1.00 h, ratio of liquid to the raw material 3.80 mL/g and ultrasonic power 230.0 W. The cell viability of PC12 cells stimulated by Glu was determined by CCK-8 assay. The levels of γ-aminobutyric (GABA), interleukin-1β (IL-1β), interleukin-4 (IL-4), tumor necrosis factor-α (TNF-α), 5-hydroxytryptamine (5-HT) and glucocorticoid receptor alpha (GR) in PC12 cells were assayed by ELISA. Furthermore, the Ca²⁺ levels in PC12 cells were determined by flow cytometry analysis. Protein and mRNA expressions of GABAA-Rα1, NMDAR1, GAD 65, GAD 67, GAT 1 and GAT 3 in PC12 cells were evaluated by real-time polymerase chain reaction (RT-PCR) and Western blotting assays. Results revealed that BBPs decreased toxic effects due to Glu treatment and decreased Ca²⁺ levels in PC12 cells. After BBPs treatments, levels of GABA and 5-HT were increased and contents of TNF-α, IL-4 and IL-1β were decreased in NGF-induced PC12 cells injured by Glu. Moreover, BBPs up-regulated the expressions of GABAA-Rα1, GAD 65 and GAD 67, whereas down-regulated that of NMDAR1 GAT 1 and GAT 3. These findings suggested that BBPs possessed protective effects on NGF-induced PC12 cells injured by Glu via γ-Aminobutyric Acid (GABA) signaling pathways, which demonstrated that BBPs has potential anti-epileptic effect in vitro. These findings may be useful in the development of novel medicine for the treatment of epilepsy.

1-Hydroxyanthraquinone exhibited antibacterial activity by regulating glutamine synthetase of Staphylococcus xylosus as a virulence factor

Staphylococcus xylosus (S. xylosus) is one of the emerging pathogens causing bovine mastitis with high rate of isolation in most of the reported clinical and field cases. To verify the role of glutamine synthetase (GS) in the pathogenesis of S. xylosus, we evaluated the virulence level of the wild-type strain and its glnA mutant strain in biofilm assays in vitro and murine infection model in vivo. From the results, it was observed that the glnA mutant strain was attenuated and could reduce tissue damage. 1-Hydroxyanthraquinone (1-HAQ) is a kind of anthraquinones, it exhibited a significant inhibitory effect on the growth of S. xylosus and biofilm formation in vitro and provided anti-inflammatory effects in vivo. In addition, the rate at which it inhibits the biofilm, inflammatory factors, and CFU of wild-type strains were significantly higher than that of the mutant strains, indicating that 1-hAQ might have pharmacological effects against S. xylosus through the regulation of GS protein. The effect of 1-hAQ on GS was further confirmed by the down-regulation of glnA expression, reduced GS activity, Gln content and the results of molecular docking. Taken together, these findings suggest that 1-hAQ facilitated a significant attenuation of S. xylosus pathogenicity by regulating the GS protein: a vital virulence factor. Therefore, it can be inferred that 1-hAQ may serve as a potential source of organic compound for the development of novel alternative drugs in mitigating the menace of bovine mastitis.

Additive Manufacturing of Nerve Decellularized Extracellular Matrix-Contained Polyurethane Conduits for Peripheral Nerve Regeneration

The nervous system is the part of our body that plays critical roles in the coordination of actions and sensory information as well as communication between different body parts through electrical signal transmissions. Current studies have shown that patients are likely to experience a functional loss if they have to go through a nerve repair for >15 mm lesion. The ideal treatment methodology is autologous nerve transplant, but numerous problems lie in this treatment method, such as lack of harvesting sites. Therefore, researchers are attempting to fabricate alternatives for nerve regeneration, and nerve conduit is one of the potential alternatives for nerve regeneration. In this study, we fabricated polyurethane/polydopamine/extracellular matrix (PU/PDA/ECM) nerve conduits using digital light processing (DLP) technology and assessed for its physical properties, biodegradability, cytocompatibility, neural related growth factor, and proteins secretion and expression and its potential in allowing cellular adhesion and proliferation. It was reported that PU/PDA/ECM nerve conduits were more hydrophilic and allowed enhanced cellular adhesion, proliferation, expression, and secretion of neural-related proteins (collagen I and laminin) and also enhanced expression of neurogenic proteins, such as nestin and microtubule-associated protein 2 (MAP2). In addition, PU/PDA/ECM nerve conduits were reported to be non-cytotoxic, had sustained biodegradability, and had similar physical characteristics as PU conduits. Therefore, we believed that PU/PDA/ECM nerve conduits could be a potential candidate for future nerve-related research or clinical applications.