Neuroprotective role of icariin in experimental spinal cord injury via its antioxidant, anti‑neuroinflammatory and anti‑apoptotic properties

Icariin promotes functional recovery in rats after spinal cord injury by inhibiting YAP and regulating PPM1B ubiquitination to inhibiting the activation of reactive astrocytes

Objective

The limited ability to regenerate axons after spinal cord injury (SCI) is influenced by factors such as astrocyte activation, reactive proliferation, and glial scar formation. The TGF-β/Smad (transforming growth factor-β/mothers against decapentaplegic homolog) pathway, associated with astrocytic scarring, plays a crucial role in recovery post-injury. This study aims to investigate how icariin (ICA) interacts with reactive astrocytes in the treatment of spinal cord injury.

Methods

A rat SCI model was constructed, and the recovery of motor function was observed after treatment with ICA.HE staining, LFB staining, immunofluorescence staining, and Western blotting were employed to assess ICA's ability to inhibit astrocyte proliferation in rats following spinal cord injury by modulating YAP, as well as to evaluate the reparative effects of ICA on the injured spinal cord tissue. Primary astrocytes were isolated and cultured. Immunoprecipitation-Western Blot (IP-WB) ubiquitination and cytoplasm-nuclear separation were employed to assess PPM1B ubiquitination and nuclear translocation.

Results

The CatWalk XT gait analysis, BBB (Basso, Beattie, and Bresnahan) score, electrophysiological measurements, HE staining, and LFB staining collectively demonstrated that ICA promotes motor function and tissue recovery following spinal cord injury in rats. Immunofluorescence staining and Western Blot analyses revealed that ICA inhibits astrocyte proliferation in rats post-spinal cord injury by suppressing YAP activity. Furthermore, the activation of YAP by XMU-MP-1 was shown to compromise the efficacy of ICA in these rats after spinal cord injury. Additional immunofluorescence staining and Western Blot experiments confirmed that ICA inhibits TGFβ1-induced astrocyte activation through the regulation of YAP. The knockdown of PPM1B (protein phosphatase, Mg2+/Mn2+-dependent 1B) in astrocytes was found to inhibit TGFβ signaling. Additionally, YAP was shown to regulate PPM1B ubiquitination and nuclear translocation through immunoprecipitation-Western blot analysis, along with the segregation of cytoplasm and nucleus.

Conclusion

Icariin promotes functional recovery in rats after spinal cord injury by inhibiting YAP and regulating PPM1B ubiquitination to inhibiting the activation of reactive astrocytes.

Exploring regulatory network of icariin synthesis in Herba Epimedii through integrated omics analysis

Herba Epimedii's leaves are highly valued in traditional Chinese medicine for their substantial concentration of flavonoids, which play a crucial role in manifesting the plant's therapeutic properties. This study investigated the metabolomic, transcriptomic and proteomic profiles of leaves from two Herba Epimedii cultivars, Epipremnum sagittatum (J) and Epipremnum pubescens (R), at three different developmental stages. Metabolite identification and analysis revealed a total of 1,412 and 1,421 metabolites with known structures were found. Flavonoids made up of 33%, including 10 significant accumulated icariin analogues. Transcriptomic analysis unveiled totally 41,644 differentially expressed genes (DEGs) containing five encoded genes participated in icariin biosynthesis pathways. Totally, 9,745 differentially expressed proteins (DEPs) were found, including Cluster-47248.2.p1 (UDP-glucuronosy/UDP-glucosyltransferase), Cluster-30441.2.p1 (O-glucosyltransferase), and Cluster-28344.9.p1 (anthocyanidin 3-O-glucoside 2 "-O-glucosyltransferase-like) through proteomics analysis which are involved to icariin biosynthesis. Protein-protein interaction (PPI) assay exhibited, totally 12 proteins showing a strong relationship of false discovery rate (FDR) <0.05 with these three proteins containing 2 leucine-rich repeat receptor kinase-like protein SRF7, and 5 methyl jasmonate esterase 1. Multi-omics connection networks uncovered 237 DEGs and 72 DEPs exhibited significant associations with the 10 icariin analogues. Overall, our integrated omics approach provides comprehensive insights into the regulatory network underlying icariin synthesis in Herba Epimedii, offering valuable resources for further research and development in medicinal plant cultivation and pharmaceutical applications.

Icariin Attenuates Human Renal Tubular Epithelial Cell Senescence by Targeting PAK2 via miR-23b-3p

BACKGROUND

Renal tubular epithelial cells (RTECs) senescence is crucial in kidney diseases. Icariin is shown to have protective effects against renal fibrosis, acute kidney injury, and proteinuria. We aimed to explore the role of icariin in protecting RTECs from senescence and the underlying mechanism involved.

METHODS

An in vitro model of RTEC senescence was established by incubating HK-2 cells with urine exosomes from patients with diabetic kidney disease. Stimulated cells were treated with icariin at various doses to evaluate the compound's therapeutic effects. After RNA transfection, cell cycle arrest and senescence, flow cytometry, and SA-β-Gal staining were analyzed. At the same time, quantitative real-time PCR examined microRNA expression. Biochemical assays.

RESULTS

Urine exosomes induced senescence and cell cycle arrest in the G1 stage in HK-2 cells, which were inhibited by icariin. Urine exosome stimulation up-regulated miR-23b-3p expression, which in turn suppressed PAK2 expression. Significantly, the induced and inhibited miR- 23b-3p expressions weakened and augmented the resistance of cells against urine exosome stimulation, respectively, while PAK2 overexpression provided additional protection. Icariin suppressed miR-23b-3p expression, and miR-23b-3p induction blocked the effects of icariin and promoted RTEC senescence.

CONCLUSION

miR-23b-3p and PAK2 form a signaling axis that regulates RTEC senescence upon urine exosome stimulation. Icariin can increase the resistance of RTECs against senescence via miR-23b-3p/PAK2. Our findings shed light on the mechanism of the clinical effects of icariin on renal diseases, which can be exploited to develop effective drugs targeting RTEC senescence in the future.

Role of traditional Chinese medicine monomers in cerebral ischemia/reperfusion injury:a review of the mechanism

Ischemia/reperfusion (I/R) injury is a pathological process wherein reperfusion of an ischemic organ or tissue exacerbates the injury, posing a significant health threat and economic burden to patients and their families. I/R triggers a multitude of physiological and pathological events, such as inflammatory responses, oxidative stress, neuronal cell death, and disruption of the blood-brain barrier (BBB). Hence, the development of effective therapeutic strategies targeting the pathological processes resulting from I/R is crucial for the rehabilitation and long-term enhancement of the quality of life in patients with cerebral ischemia/reperfusion injury (CIRI). Traditional Chinese medicine (TCM) monomers refer to bioactive compounds extracted from Chinese herbal medicine, possessing anti-inflammatory and antioxidative effects, and the ability to modulate programmed cell death (PCD). TCM monomers have emerged as promising candidates for the treatment of CIRI and its subsequent complications. Preclinical studies have demonstrated that TCM monomers can enhance the recovery of neurological function following CIRI by mitigating oxidative stress, suppressing inflammatory responses, reducing neuronal cell death and functional impairment, as well as minimizing cerebral infarction volume. The neuroprotective effects of TCM monomers on CIRI have been extensively investigated, and a comprehensive understanding of their mechanisms can pave the way for novel approaches to I/R treatment. This review aims to update and summarize evidence of the protective effects of TCMs in CIRI, with a focus on their role in modulating oxidative stress, inflammation, PCD, glutamate excitotoxicity, Ca2+ overload, as well as promoting blood-brain barrier repairment and angiogenesis. The main objective is to underscore the significant contribution of TCM monomers in alleviating CIRI.

Network pharmacology integrated with experimental validation to explore the therapeutic role and potential mechanism of Epimedium for spinal cord injury

Objective

Epimedium (EPI) is a common Chinese herb with neuroprotective effects against a variety of central nervous system disorders, especially spinal cord injury (SCI). In this study, we performed network pharmacology and molecular docking analyses to reveal the mechanism underlying EPI treatment of SCI, then validated its efficacy using animal models.

Methods

The active ingredients and targets of EPI were screened by Traditional Chinese Medicine Systems Pharmacology (TCMSP) and their targets annotated on the UniProt platform. SCI-related targets were searched from OMIM, TTD, and GeneCards databases. We employed the STRING platform to construct a protein-protein interaction (PPI) network then visualized the results using Cytoscape (3.8.2) software. We also subjected key EPI targets to ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, then docked the main active ingredients with the key targets. Finally, we established an SCI rat model to evaluate efficacy of EPI in treating SCI and validate the effects of different biofunctional modules predicted by network pharmacology.

Results

A total of 133 EPI targets were associated with SCI. GO terms and KEGG pathway enrichment results showed that EPI's effect in treating SCI was significantly associated with inflammatory response, oxidative stress and the PI3K/AKT signaling pathway. Molecular docking results indicated that EPI's active ingredients have a high affinity for the key targets. Results from animal experiments revealed that EPI not only markedly improved Basso, Beattie, and Bresnahan scores in SCI rats, but also significantly improved p-PI3K/PI3K and p-AKT/AKT ratio. Moreover, EPI treatment not only mediated a significant decrease in malondialdehyde (MDA) but also increased both superoxide dismutase (SOD), and glutathione (GSH). However, this phenomenon was successfully reversed by LY294002, a PI3K inhibitor.

Conclusion

EPI improves behavioral performance in SCI rats through anti-oxidative stress, which may be mediated by activation of the PI3K/AKT signaling pathway.

Ginsenoside Rb1 improves energy metabolism after spinal cord injury

Mitochondrial damage caused by oxidative stress and energy deficiency induced by focal ischemia and hypoxia are important factors that aggravate diseases. Studies have shown that ginsenoside Rb1 has neurotrophic and neuroprotective effects. However, whether it influences energy metabolism after spinal cord injury remains unclear. In this study, we treated mouse and cell models of spinal cord injury with ginsenoside Rb1. We found that ginsenoside Rb1 remarkably inhibited neuronal oxidative stress, protected mitochondria, promoted neuronal metabolic reprogramming, increased glycolytic activity and ATP production, and promoted the survival of motor neurons in the anterior horn and the recovery of motor function in the hind limb. Because sirtuin 3 regulates glycolysis and oxidative stress, mouse and cell models of spinal cord injury were treated with the sirtuin 3 inhibitor 3-TYP. When Sirt3 expression was suppressed, we found that the therapeutic effects of ginsenoside Rb1 on spinal cord injury were remarkably inhibited. Therefore, ginsenoside Rb1 is considered a potential drug for the treatment of spinal cord injury, and its therapeutic effects are closely related to sirtuin 3.

Zein-Stabilized Nanospheres as Nanocarriers for Boosting the Aphrodisiac Activity of Icariin: Response Surface Optimization and In Vivo Assessment

Icariin (ICA), a main active compound of the Epimedium genus, is used as an aphrodisiac in traditional Chinese herbal medicine. Despite its therapeutic efficacy, ICA displays reduced oral absorption, and therefore, low bioavailability hindered its clinical application. Implementing nanotechnology in the field of formulation has been a focus to improve the efficacy of ICA. In this regard, polymeric nanoparticles find a potential application as drug delivery systems. A nanosphere formula was designed, aiming to improve the drug's efficacy. The proposed ICA nanosphere formula (tocozeinolate) was optimized using D-optimal response surface design. The concentrations of ICA (X1), D-α-tocopherol polyethylene glycol 1000 succinate (TPGS, X2), zein (X3), and sodium deoxycholate (SDC, X4) expressed as percentages were investigated as quantitative independent variables. As per the experimental design, 23 formulations were developed, which were investigated for particle size (PS, nm), zeta potential (ZP, mV), and entrapment efficiency (EE, %) as response parameters. Numerical optimization and desirability approach were employed to predict the optimized variable levels that, upon combination, could result in minimized size and maximized zeta potential and ICA entrapment. The optimized ICA-tocozeinolate nanospheres showed a particle size of 224.45 nm, zeta potential of 0.961 mV, and drug entrapment of 65.29% that coincide well with the predicted values. The optimized ICA-tocozeinolate nanospheres were evaluated for sexual behavior in Wistar male rats compared to raw ICA at equivalent doses (20 mg/kg). In vivo assessment results showed significant sexual behavior enhancement by the optimized formulation, as evidenced by decreased average time of both mount latency (ML) and ejaculation latency (EL) to almost half those of raw ICA. Additionally, intromission latency (IL) time was reduced by 41% compared to the raw ICA. These results highlighted the potential of the proposed ICA-tocozeinolate nanospheres as a promising platform for improving the delivery and efficacy of therapeutic agents.

Traditional Chinese Medicine Monomers: Novel Strategy for Endogenous Neural Stem Cells Activation After Stroke

Stem cell therapy, which has become a potential regenerative medical treatment and a promising approach for treating brain injuries induced by different types of cerebrovascular disease, has various application methods. Activation of endogenous neural stem cells (NSCs) can enable infarcted neuron replacement and promote neural networks’ regeneration without the technical and ethical issues associated with the transplantation of exogenous stem cells. Thus, NSC activation can be a feasible strategy to treat central nervous system (CNS) injury. The potential molecular mechanisms of drug therapy for the activation of endogenous NSCs have gradually been revealed by researchers. Traditional Chinese medicine monomers (TCMs) are active components extracted from Chinese herbs, and some of them have demonstrated the potential to activate proliferation and neurogenesis of NSCs in CNS diseases. Ginsenoside Rg1, astragaloside IV (AST), icariin (ICA), salvianolic acid B (Sal B), resveratrol (RES), curcumin, artesunate (ART), and ginkgolide B (GB) have positive effects on NSCs via different signaling pathways and molecules, such as the Wingless/integrated/β-catenin (Wnt/β-catenin) signaling pathway, the sonic hedgehog (Shh) signaling pathway, brain-derived neurotrophic factor (BDNF), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1). This article may provide further motivation for researchers to take advantage of TCMs in studies on CNS injury and stem cell therapy.

The Pathogenesis of Neurotrauma Indicates Targets for Neuroprotective Therapies

The spinal cord injury (SCI) initiates an extraordinarily protracted disease with 3 phases; acute, inflammatory, and resolution that are restricted to the cavity of injury (COI) or arachnoiditis by a unique CNS reaction against the severity of destructive inflammation. While the severity of inflammation involving the white matter is fueled by a potently immunogenic activity of damaged myelin, its sequestration in the COI and its continuity with the cerebrospinal fluid of the subdural space allow anti-inflammatory therapeutics infused subdurally to inhibit phagocytic macrophage infiltration and thus provide neuroprotection. The role of astrogliosis in containing and ultimately in eliminating severe destructive inflammation post-trauma appears obvious but is not yet sufficiently understood to use in therapeutic neuroprotective and neuroregenerative strategies. An apparent antiinflammatory activity of reactive astrocytes is paralleled by their active role in removing excess edema fluid in blood-brain barrier damaged by inflammation. Recently elucidated pathogenesis of neurotrauma, including SCI, traumatic brain injury (TBI), and stroke, calls for the following principal therapeutic steps in its treatment leading to the recovery of neurologic function: (1) inhibition and elimination of destructive inflammation from the COI with accompanying reduction of vasogenic edema, (2) insertion into the COI of a functional bridge supporting the crossing of regenerating axons, (3) enabling regeneration of axons to their original synaptic targets by temporary safe removal of myelin in targeted areas of white matter, (4) in vivo, systematic monitoring of the consecutive therapeutic steps. The focus of this paper is on therapeutic step 1.

Icariin enhances AMP-activated protein kinase and prevents high fructose and high salt-induced metabolic syndrome in rats

Metabolic syndrome (MetS) is an increasing health threat and often leads to cardiovascular complications. The aim of this study was to evaluate icariin’s ability to combat MetS induced in rats and outline the involved mechanisms of action. Rats were grouped in four batches. The controls received a regular diet and water. MetS was induced in the remaining three groups using a high-salt high-fructose diet. Groups 1 and 2 were given daily doses of saline, while Groups 3 and 4 received 25 and 50 mg/kg icariin, respectively, for 12 weeks in total. The experimental protocol was carried out for 12 weeks consecutively. Icariin significantly decreased body mass index (BMI), adiposity index and body weight. Further, icariin protected against dyslipidemia, hyperglycemia, and hyperinsulinemia and improved insulin resistance as given by the homeostatic model assessment of insulin resistance (HOMA-IR) values. Icariin guarded against the rise in serum interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). In addition, it significantly inhibited the decrease in mRNA expression of glucose transporter type 4 (GLUT4) and liver kinase B1 (LKB1). These effects were accompanied by decreased liver content of nuclear factor kappa B (NFκB) and enhanced serum levels of phosphorylated 5ʹ-adenosine monophosphate-activated protein kinase (p-AMPK). Further, icariin significantly increased p-AMPK/AMPK ratio in liver tissues. Conclusively, icariin offers protection in experimentally induced MetS, partially due to AMPK activation.

Optimized Icariin Phytosomes Exhibit Enhanced Cytotoxicity and Apoptosis-Inducing Activities in Ovarian Cancer Cells

Icariin (ICA) is a flavonol glycoside that has pleiotropic pharmacological actions. It has cytotoxic effects against ovarian cancer cells and increases their chemosensitivity to chemotherapeutic drugs. Phytosomes are identified for their potential in drug delivery of cytotoxic agents. Thus, the purpose of this study was to determine the potential enhancement of ICA cytotoxicity activity in OVCAR-3 ovarian cancer cells via its formulation in phytosomes. ICA-phytosomal formulation was optimized using a Box-Behnken design. Particle size, shape, and in vitro drug release were used to characterize the optimized formula. The optimized formulation exhibited enhanced in vitro drug release. ICA-phytosomes exhibited enhanced cytotoxicity against ovarian cancer cells. Cell cycle analysis indicated accumulation of cells challenged with ICA-phytosomes in G2/M and pre-G1 phases. Staining of cells with annexin V indicated significant elevation of percentage cells with early and late apoptosis as well as total cell death. In addition, the formulation significantly disturbed mitochondrial membrane potential and cellular content of caspase 3. In addition, intracellular release of reactive oxygen species (ROS) was enhanced by ICA-phytosomes. In conclusion, phytosome formulation of ICA significantly potentiates its cytotoxic activities against OVCAR-3 cells. This is mediated, at least partly, by enhanced ICA cellular permeation, apoptosis, and ROS.

The Lipoxin A4 Receptor Agonist BML-111 Alleviates Inflammatory Injury and Oxidative Stress in Spinal Cord Injury

Background

Spinal cord injury (SCI) has a high incidence and causes serious harm. Lipoxin A4 (LXA4) receptor agonist BML-111 was reported to regulate inflammation and oxidative stress. The goal of this study was to assess whether BML-111 could protect against SCI by suppressing inflammation and oxidative stress.

Material/Methods

We developed a rat SCI model, then BML-111 was intraperitoneally injected into SCI rats to observe the BML-111 function. The pathological changes of SCI were observed with hematoxylin and eosin (HE) staining. Motor function of rats were assessed by the modified Tarlov’s scale. ELISA was used to assess the changes in levels of TNF-α, IL-1β, and IL-6. Western blot analysis was performed to assess the expressions of TNF-α, IL-1β, IL-6, Bcl2, Bax, and cleaved caspase3 in spinal cord tissue. TOS and TAS in rat serum were detected by xylenol orange method and ABTS method, respectively. The apoptotic cells in spinal cord tissue were observed with TUNEL assay.

Results

The results indicated that BML-111 effectively improved the SCI and motor function of rats. BML-111 treatment decreased the levels of TNF-α, IL-1β, and IL-6 in serum and spinal cord tissue, as well as decreasing the levels of TOS and TAS and cell apoptosis.

Conclusions

BML-111 alleviated inflammation and oxidative stress in SCI rats.

Role of Nuclear Factor Kappa B (NF-κB) Signalling in Neurodegenerative Diseases: An Mechanistic Approach

A transcriptional regulatory nuclear factor kappa B (NF-κB) protein is a modulator of cellular biological activity via binding to a promoter region in the nucleus and transcribing various protein genes. The recent research implicated the intensive role of nuclear factor kappa B (NF-κB) in diseases like autoimmune disorder, inflammatory, cardiovascular and neurodegenerative diseases. Therefore, targeting the nuclear factor kappa B (NF-κB) protein offers a new opportunity as a therapeutic approach. Activation of IκB kinase/NF-κB signaling pathway leads to the development of various pathological conditions in human beings, such as neurodegenerative, inflammatory disorders, autoimmune diseases, and cancer. Therefore, the transcriptional activity of IκB kinase/NF- κB is strongly regulated at various cascade pathways. The nuclear factor NF-kB pathway plays a major role in the expression of pro-inflammatory genes, including cytokines, chemokines, and adhesion molecules. In response to the diverse stimuli, the cytosolic sequestered NF-κB in an inactivated form by binding with an inhibitor molecule protein (IkB) gets phosphorylated and translocated into the nucleus further transcribing various genes necessary for modifying various cellular functions. The various researches confirmed the role of different family member proteins of NF-κB implicated in expressing various genes products and mediating various cellular cascades. MicroRNAs, as regulators of NF- κB microRNAs play important roles in the regulation of the inflammatory process. Therefore, the inhibitor of NF-κB and its family members plays a novel therapeutic target in preventing various diseases. Regulation of NF- κB signaling pathway may be a safe and effective treatment strategy for various disorders.

Active compounds of herbs ameliorate impaired cognition in APP/PS1 mouse model of Alzheimer's disease

Alzheimer's disease (AD), the most common cause of dementia, is a neurodegenerative disorder characterized by amyloid plaque accumulations, intracellular tangles and neuronal loss in certain brain regions. It has been shown that a disturbance of normal iron metabolism contributes to the pathophysiology of AD. However, the mechanism underlying abnormal iron load in the brain of AD patients is unclear. The frontal cortex, an important brain structure for executive function, is one of the regions affected by AD. We investigated the beneficial effects of active compounds of Epimedium, Astragaoside and Puerarin on iron metabolism in the frontal cortex of six-month-old APPswe/PS1_ΔE9 (APP/PS1) double transgenic mouse, a model of AD. Treatment with the active compounds reduced cognitive and memory deficits and damaged cell ultrastructure in APP/PS1 mice. These beneficial effects were associated with changes in expression levels of iron metabolism proteins in the frontal cortex, including divalent metal transporter with iron response element (DMT1-with IRE), divalent metal transporter without iron response element (DMT1-without IRE), transferrin (TF) and transferring receptor 1 (TfR1); three release proteins including the exporter ferroportin 1 (Fpn1), ceruloplasmin (CP) and hephaestin (HEPH), one increased storage iron protein ferritin and one iron regulating hormone hepcidin. These findings suggest that the active compounds improve cognition and memory in brain neurodegenerative disorders and these beneficial effects are associated with reduced impairment of iron metabolism. This study may provide a new strategy for developing novel drugs to treat AD.