Neuroprotective Effect of SCM-198 through Stabilizing Endothelial Cell Function

Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology

Leonurine is an alkaloid unique to the Leonurus genus, which has many biological activities, such as uterine contraction, anti-inflammation, anti-oxidation, regulation of cell apoptosis, anti-tumor, angiogenesis, anti-platelet aggregation, and inhibition of vasoconstriction. This paper summarizes the extraction methods, synthetic pathways, biosynthetic mechanisms, pharmacokinetic properties, pharmacological effects in various diseases, toxicology, and clinical trials of leonurine. To facilitate a successful transition into clinical application, intensified efforts are required in several key areas: structural modifications of leonurine to optimize its properties, comprehensive pharmacokinetic assessments to understand its behavior within the body, thorough mechanistic studies to elucidate how it works at the molecular level, rigorous safety evaluations and toxicological investigations to ensure patient wellbeing, and meticulously conducted clinical trials to validate its efficacy and safety profile.

SIRT1 restores mitochondrial structure and function in rats by activating SIRT3 after cerebral ischemia/reperfusion injury

Mitochondrial dysfunction contributes to cerebral ischemia-reperfusion (CI/R) injury, which can be ameliorated by Sirtuin-3 (SIRT3). Under stress conditions, the SIRT3-promoted mitochondrial functional recovery depends on both its activity and expression. However, the approach to enhance SIRT3 activity after CI/R injury remains unelucidated. In this study, Sprague-Dawley (SD) rats were intracranially injected with either adeno-associated viral Sirtuin-1 (AAV-SIRT1) or AAV-sh_SIRT1 before undergoing transient middle cerebral artery occlusion (tMCAO). Primary cortical neurons were cultured and transfected with lentiviral SIRT1 (LV-SIRT1) and LV-sh_SIRT1 respectively before oxygen-glucose deprivation/reoxygenation (OGD/R). Afterwards, rats and neurons were respectively treated with a selective SIRT3 inhibitor, 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP). The expression, function, and related mechanism of SIRT1 were investigated by Western Blot, flow cytometry, immunofluorescence staining, etc. After CI/R injury, SIRT1 expression decreased in vivo and in vitro. The simulation and immune-analyses reported strong interaction between SIRT1 and SIRT3 in the cerebral mitochondria before and after CI/R. SIRT1 overexpression enhanced SIRT3 activity by increasing the deacetylation of SIRT3, which ameliorated CI/R-induced cerebral infarction, neuronal apoptosis, oxidative stress, neurological and motor dysfunction, and mitochondrial respiratory chain dysfunction, promoted mitochondrial biogenesis, and retained mitochondrial integrity and mitochondrial morphology. Meanwhile, SIRT1 overexpression alleviated OGD/R-induced neuronal death and mitochondrial bioenergetic deficits. These effects were reversed by AAV-sh_SIRT1 and the neuroprotective effects of SIRT1 were partially offset by 3-TYP. These results suggest that SIRT1 restores the structure and function of mitochondria by activating SIRT3, offering neuroprotection against CI/R injury, which signifies a potential approach for the clinical management of cerebral ischemia.

Multiomics analyses of two Leonurus species illuminate leonurine biosynthesis and its evolution

The Lamiaceae family is renowned for its terpenoid-based medicinal components, but Leonurus, which has traditional medicinal uses, stands out for its alkaloid-rich composition. Leonurine, the principal active compound found in Leonurus, has demonstrated promising effects in reducing blood lipids and treating strokes. However, the biosynthetic pathway of leonurine remains largely unexplored. Here, we present the chromosome-level genome sequence assemblies of Leonurus japonicus, known for its high leonurine production, and Leonurus sibiricus, characterized by very limited leonurine production. By integrating genomics, RNA sequencing, metabolomics, and enzyme activity assay data, we constructed the leonurine biosynthesis pathway and identified the arginine decarboxylase (ADC), uridine diphosphate glucosyltransferase (UGT), and serine carboxypeptidase-like (SCPL) acyltransferase enzymes that catalyze key reactions in this pathway. Further analyses revealed that the UGT-SCPL gene cluster evolved by gene duplication in the ancestor of Leonurus and neofunctionalization of SCPL in L. japonicus, which contributed to the accumulation of leonurine specifically in L. japonicus. Collectively, our comprehensive study illuminates leonurine biosynthesis and its evolution in Leonurus.

NADPH Oxidases and Oxidative Stress in the Pathogenesis of Atrial Fibrillation

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and its prevalence increases with age. The irregular and rapid contraction of the atria can lead to ineffective blood pumping, local blood stasis, blood clots, ischemic stroke, and heart failure. NADPH oxidases (NOX) and mitochondria are the main sources of reactive oxygen species in the heart, and dysregulated activation of NOX and mitochondrial dysfunction are associated with AF pathogenesis. NOX- and mitochondria-derived oxidative stress contribute to the onset of paroxysmal AF by inducing electrophysiological changes in atrial myocytes and structural remodeling in the atria. Because high atrial activity causes cardiac myocytes to expend extremely high energy to maintain excitation-contraction coupling during persistent AF, mitochondria, the primary energy source, undergo metabolic stress, affecting their morphology, Ca2+ handling, and ATP generation. In this review, we discuss the role of oxidative stress in activating AF-triggered activities, regulating intracellular Ca2+ handling, and functional and anatomical reentry mechanisms, all of which are associated with AF initiation, perpetuation, and progression. Changes in the extracellular matrix, inflammation, ion channel expression and function, myofibril structure, and mitochondrial function occur during the early transitional stages of AF, opening a window of opportunity to target NOX and mitochondria-derived oxidative stress using isoform-specific NOX inhibitors and mitochondrial ROS scavengers, as well as drugs that improve mitochondrial dynamics and metabolism to treat persistent AF and its transition to permanent AF.

Neutrophil membrane fusogenic nanoliposomal leonurine for targeted ischemic stroke therapy via remodeling cerebral niche and restoring blood-brain barrier integrity

Ischemic stroke (IS) constitutes the leading cause of global morbidity and mortality. Neuroprotectants are essential to ameliorate the clinical prognosis, but their therapeutic outcomes are tremendously compromised by insufficient delivery to the ischemic lesion and intricate pathogenesis associated with neuronal damage, oxidative stress, inflammation responses, blood-brain barrier (BBB) dysfunction, etc. Herein, a biomimetic nanosystem (Leo@NM-Lipo) composed of neutrophil membrane-fused nanoliposomal leonurine (Leo) is constructed, which can not only efficiently penetrate and repair the disrupted BBB but also robustly remodel the harsh cerebral microenvironment to reverse ischemia-reperfusion (I/R) injury. More specifically, the neutrophil membrane inherits the BBB penetrating, infarct core targeting, inflammation neutralization, and immune evasion properties of neutrophils, while Leo, a naturally occurring neuroprotectant, exerts pleiotropic effects to attenuate brain damage. Remarkably, comprehensive investigations disclose the critical factors influencing the targetability and therapeutic performances of biomimetic nanosystems. Leo@NM-Lipo with a low membrane protein-to-lipid ratio of 1:10 efficiently targets the ischemic lesion and rescues the injured brain by alleviating neuronal apoptosis, oxidative stress, neuroinflammation, and restoring BBB integrity in transient middle cerebral artery occlusion (tMCAO) rats. Taken together, our study provides a neutrophil-mimetic nanoplatform for targeted IS therapy and sheds light on the rational design of biomimetic nanosystems favoring wide medical applications.

Anethole Pretreatment Modulates Cerebral Ischemia/Reperfusion: The Role of JNK, p38, MMP-2 and MMP-9 Pathways

Anethole (AN) is one of the major constituents of several plant oils, demonstrating plentiful pharmacological actions. Ischemic stroke is the main cause of morbidity and death worldwide, particularly since ischemic stroke therapeutic choices are inadequate and limited; thus, the development of new therapeutic options is indispensable. This study was planned to explore the preventive actions of AN in ameliorating cerebral ischemia/reperfusion-induced brain damage and BBB permeability leakage, as well as to explore anethole’s potential mechanisms of action. The proposed mechanisms included modulating JNK and p38 as well as MMP-2 and MMP-9 pathways. Sprague–Dawley male rats were randomly assigned into four groups: sham, middle cerebral artery occlusion (MCAO), AN125 + MCAO, and AN250 + MCAO. Animals in the third and fourth groups were pretreated with AN 125 or 250 mg/kg orally, respectively, for two weeks before performing middle cerebral artery occlusion (MCAO)-induced cerebral ischemic/reperfusion surgery. Animals that experienced cerebral ischemia/reperfusion exhibited amplified infarct volume, Evans blue intensity, brain water content, Fluoro-Jade B-positive cells, severe neurological deficits, and numerous histopathological alterations. MCAO animals exhibited elevated MMP-9 and MMP-2 gene expressions, enzyme activities, augmented JNK, and p38 phosphorylation. On the other hand, pretreatment with AN diminished the infarct volume, Evans blue dye intensity, brain water content, and Fluoro-Jade B-positive cells, improved the neurological score and enhanced histopathological examination. AN effectively lowered MMP-9 and MMP-2 gene expression and enzyme activities and diminished phosphorylated JNK, p38. AN decreased MDA content, amplified GSH/GSSG ratio, SOD, and CAT, decreased the serum and brain tissue homogenate inflammatory cytokines (TNF-α, IL-6, IL-1β), NF-κB, and deterred the apoptotic status. This study revealed the neuroprotective ability of AN against cerebral ischemia/reperfusion in rats. AN boosted blood–brain barrier integrity via modulating MMPs and diminished oxidative stress, inflammation, and apoptosis through the JNK/p38 pathway.

Quercetin alleviates kainic acid-induced seizure by inhibiting the Nrf2-mediated ferroptosis pathway

BACKGROUND

Epilepsy is one of the most common neurological disorders in childhood. However, classical antiepileptic drugs are linked with drug toxicity and cognitive function impairment in children. Hence, it is essential to develop a novel therapy to solve this problem. Currently, studies indicate regulating the nuclear factor-erythroid 2-related factor 2 (Nrf2)-mediated ferroptosis pathway represents a potential advanced therapy for seizures. Hence, the present study aimed to explore whether quercetin, a natural polyphenol, could alleviate seizure-induced neuron death and preserve cognitive function by inhibiting Nrf2-mediated ferroptosis.

METHODS

Kainic acid-induced epileptic mice model, morris water maze (MWM) test, cell counting kit-8 (CCK-8) assays, western blotting analysis, enzyme-linked immunosorbent assay, flow cytometry, quantitative real-time reverse transcription PCR (qRT-PCR), immunofluorescence staining, and RNA sequencing analysis were employed to explore the potential mechanisms by which quercetin exerts protective effects on seizure-induced neuron death in kainic acid-induced epileptic mice model and glutamate-induced HT22 neuronal cell death.

RESULTS

Our findings suggested the association between the Nrf2-mediated ferroptosis pathway and seizures in a clinical setting. Quercetin pretreatment alleviates seizure-like behaviors and cognitive impairment in KA-induced epileptic mice. Additionally, in vitro, co-treatment with quercetin effectively exerts neuroprotective effects in glutamate-induced HT22 neuronal cell death. These protective effects were also closely linked to regulating the Nrf2-mediated ferroptosis pathway. Furthermore, bioinformatic profiling revealed that the SIRT1/Nrf2/SLC7A11/GPX4 pathway plays a crucial role in the Glu-induced HT22 cell death pretreated with quercetin.

CONCLUSIONS

These findings indicated that quercetin effectively protects against seizure-induced neuron death in vivo and in vitro and alleviates cognitive function impairment via the SIRT1/Nrf2/SLC7A11/GPX4 pathway.

4-Ethylguaiacol Modulates Neuroinflammation and Promotes Heme Oxygenase-1 Expression to Ameliorate Brain Injury in Ischemic Stroke

Ischemic stroke is caused by a sudden reduction in cerebral blood flow that subsequently induces a complex cascade of pathophysiological responses, leading to brain inflammation and irreversible infarction. 4-ethylguaiacol (4-EG) is reported to suppress inflammatory immune responses. However, whether 4-EG exerts anti-inflammatory effects in ischemic stroke remains unexplored. We evaluated the therapeutic potential of 4-EG and examined the cellular and molecular mechanisms underlying the protective effects of 4-EG in ischemic stroke. The effect of 4-EG in ischemic stroke was determined by using a transient middle cerebral artery occlusion (MCAO) animal model followed by exploring the infarct size, neurological deficits, microglia activation, inflammatory cytokine production, blood–brain barrier (BBB) disruption, brain endothelial cell adhesion molecule expression, and microglial heme oxygenase-1 (HO-1) expression. Nrf2^-/- and HO-1 inhibitor ZnPP-treated mice were also subjected to MCAO to evaluate the role of the Nrf2/HO-1 pathway in 4-EG-mediated protection in ischemic stroke. We found that 4-EG attenuated infarct size and neurological deficits, and lessened BBB disruption in ischemic stroke. Further investigation revealed that 4-EG suppressed microglial activation, peripheral inflammatory immune cell infiltration, and brain endothelial cell adhesion molecule upregulation in the ischemic brain. Finally, we identified that the protective effect of 4-EG in ischemic stroke was abolished in Nrf2^-/– and ZnPP-treated MCAO mice. Our results identified that 4-EG confers protection against ischemic stroke and reveal that the protective effect of 4-EG in ischemic stroke is mediated through the induction of the Nrf2/HO1 pathway. Thus, our findings suggest that 4-EG could be developed as a novel therapeutic agent for the treatment of ischemic stroke.

Oxidative Injury in Ischemic Stroke: A Focus on NADPH Oxidase 4

Ischemic stroke is a leading cause of disability and mortality worldwide. Thus, it is urgent to explore its pathophysiological mechanisms and find new therapeutic strategies for its successful treatment. The relationship between oxidative stress and ischemic stroke is increasingly appreciated and attracting considerable attention. ROS serves as a source of oxidative stress. It is a byproduct of mitochondrial metabolism but primarily a functional product of NADPH oxidases (NOX) family members. Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) is most closely related to the formation of ROS during ischemic stroke. Its expression is significantly upregulated after cerebral ischemia, making it a promising target for treating ischemic stroke. Several drugs targeting NOX4, such as SCM-198, Iso, G-Rb1, betulinic acid, and electroacupuncture, have shown efficacy as treatments of ischemic stroke. MTfp-NOX4 POC provides a novel insight for the treatment of stroke. Combinations of these therapies also provide new approaches for the therapy of ischemic stroke. In this review, we summarize the subcellular location, expression, and pathophysiological mechanisms of NOX4 in the occurrence and development of ischemic stroke. We also discuss the therapeutic strategies and related regulatory mechanisms for treating ischemic stroke. We further comment on the shortcomings of current NOX4-targeted therapy studies and the direction for improvement.

Electro-Acupuncture Improve the Early Pattern Separation in Alzheimer’s Disease Mice via Basal Forebrain-Hippocampus Cholinergic Neural Circuit

Objectives

To explore the effect of electro-acupuncture (EA) treatment on pattern separation and investigate the neural circuit mechanism involved in five familial mutations (5 × FAD) mice.

Methods

Five familial mutations mice were treated with EA at Baihui (DU20) and Shenting (DU24) acupoints for 30 min each, lasting for 4 weeks. Cognitive-behavioral tests were performed to evaluate the effects of EA treatment on cognitive functions. ¹H-MRS, Nissl staining, immunohistochemistry, and immunofluorescence were performed to examine the cholinergic system alteration. Thioflavin S staining and 6E10 immunofluorescence were performed to detect the amyloid-β (Aβ). Furthermore, hM4Di designer receptors exclusively activated by designer drugs (DREADDs) virus and long-term clozapine-N-oxide injection were used to inhibit the medial septal and vertical limb of the diagonal band and dentate gyrus (MS/VDB-DG) cholinergic neural circuit. Cognitive-behavioral tests and immunofluorescence were performed to investigate the cholinergic neural circuit mechanism of EA treatment improving cognition in 5 × FAD mice.

Results

Electro-acupuncture treatment significantly improved spatial recognition memory and pattern separation impairment, regulated cholinergic system via reduction neuron loss, upregulation of choline/creatine, choline acetyltransferase, vesicular acetylcholine transporter, and downregulation of enzyme acetylcholinesterase in 5 × FAD mice. Aβ deposition was reduced after EA treatment. Subsequently, the monosynaptic hM4Di DREADDs virus tracing and inhibiting strategy showed that EA treatment activates the MS/VDB-DG cholinergic neural circuit to improve the early pattern separation. In addition, EA treatment activates this circuit to upregulating M1 receptors positive cells and promoting hippocampal neurogenesis in the dentate gyrus (DG).

Conclusion

Electro-acupuncture could improve the early pattern separation impairment by activating the MS/VDB-DG cholinergic neural circuit in 5 × FAD mice, which was related to the regulation of the cholinergic system and the promotion of neurogenesis by EA treatment.

SCM-198 Can Regulate Autophagy Through the Bax/Bcl-2/TLR4 Pathway to Alleviate Renal Ischemia-Reperfusion Injury

Renal ischemia-reperfusion (I/R) injury is frequently observed in several clinical cases. In this study, we want to investigate that SCM-198 attenuates renal injury in the renal I/R model and find out the possible mechanisms. Wistar albino 40 male rats were classified into four groups (n=10): control, DMSO, I/R, and SCM-198 30 mg/kg. In the group 4, SCM-198 was administered intraperitoneally once at the doses of 30 mg/kg following the reperfusion. Glomerular associated proteins (PCX), tubular damage factors (NGAL, KIM-1), blood urea nitrogen (BUN), serum creatinine, inflammatory cytokines (IL-1β, IL-18, and TNF-α), Bax/Bcl-2, TLR4, LC3B, and Beclin-1 were evaluated. SCM-198 played an essential role in mitigating kidney damage. SCM-198 alleviated tubular damage and decreased IL-1β, IL-18, and TNF-α levels. SCM-198 reduced the apoptosis marker Bax/Bcl-2 ratio, immune system protein TLR4, and autophagy proteins LC3B and Beclin-1. In brief, our results support the notion that SCM-198 has protective effects on I/R-induced renal injury. SCM-198 therapy may be a new alternative for the prevention and treatment of renal I/R injury.

Succinate accumulation contributes to oxidative stress and iron accumulation in pentylenetetrazol-induced epileptogenesis and kainic acid-induced seizure

This study explored the role of succinate accumulation in the oxidative stress and iron accumulation in both pentylenetetrazol (PTZ)-induced epileptogenesis and kainic acid (KA)-induced status epilepticus (SE). The levels of succinate, oxidative stress, iron content, iron-related protein expression, and the severity of neuronal injury and seizures were measured in both models. We found that increased concentrations of succinate were associated with increased levels of oxidative stress, iron content, iron regulator protein, and iron importer divalent metal transporter 1, as well as decreased levels of iron exporter ferropotin 1. Aggravated neuronal injury was observed in the hippocampi and cortices of both models. The cell-permeable molecule dimethyl malonate (DM), a competitive inhibitor of succinate dehydrogenase (SDH), significantly attenuated succinate accumulation, reduced the oxidative stress and iron levels, and mitigated the severity of the seizures and neuronal injury. Our results thus indicate that the accumulation of succinate due to the reverse catalysis of SDH may exacerbate oxidative stress and thus induce iron accumulation and neuronal injury in both models. Targeting succinate accumulation may achieve neuroprotective and anti-seizure effects.

H2S protects hippocampal neurons against hypoxia-reoxygenation injury by promoting RhoA phosphorylation at Ser188

Inhibition of RhoA-ROCK pathway is involved in the H₂S-induced cerebral vasodilatation and H₂S-mediated protection on endothelial cells against oxygen-glucose deprivation/reoxygenation injury. However, the inhibitory mechanism of H₂S on RhoA-ROCK pathway is still unclear. The aim of this study was to investigate the target and mechanism of H₂S in inhibition of RhoA/ROCK. GST-RhoA^wild and GST-RhoA^S188A proteins were constructed and expressed, and were used for phosphorylation assay in vitro. Recombinant RhoA^wild-pEGFP-N1 and RhoA^S188A-pEGFP-N1 plasmids were constructed and transfected into primary hippocampal nerve cells (HNCs) to evaluate the neuroprotective mechanism of endothelial H₂S by using transwell co-culture system with endothelial cells from cystathionine-γ-lyase knockout (CSE^-/-) mice and 3-mercaptopyruvate sulfurtransferase knockout (3-MST^-/-) rats, respectively. We found that NaHS, exogenous H₂S donor, promoted RhoA phosphorylation at Ser188 in the presence of cGMP-dependent protein kinase 1 (PKG1) in vitro. Besides, both exogenous and endothelial H₂S facilitated the RhoA phosphorylation at Ser188 in HNCs, which induced the reduction of RhoA activity and membrane transposition, as well as ROCK₂ activity and expression. To further investigate the role of endothelial H₂S on RhoA phosphorylation, we detected H₂S release from ECs of CSE^+/+ and CSE^-/- mice, and 3-MST^+/+ and 3-MST^-/- rats, respectively, and found that H₂S produced by ECs in the culture medium is mainly catalyzed by CSE synthase. Moreover, we revealed that both endothelial H₂S, mainly catalyzed by CSE, and exogenous H₂S protected the HNCs against hypoxia-reoxygenation injury via phosphorylating RhoA at Ser188.

Mitochondrial Targeting of Herbal Medicine in Chronic Kidney Disease

Chronic kidney disease (CKD) is a common progressive disease that is typically characterized by the permanent loss of nephrons and an eventual decline in glomerular filtration rate. CKD increases mortality and has a significant impact on the quality of life and the economy, which is becoming a major public health issue worldwide. Since current conventional-medicine treatment options for CKD are not satisfactory, many patients seek complementary and alternative medicine treatments including Traditional Chinese Medicine. Herbal medicine is often used to relieve symptoms of renal diseases in the clinic. The kidney is abundant in the number of mitochondria, which provide enough energy for renal function and metabolism. In recent years, a vital role for mitochondrial dysfunction has been suggested in CKD. Mitochondria have become a new target for the treatment of diseases. A growing number of studies have demonstrated herbal medicine could restore mitochondrial function and alleviate renal injury both in vivo and in vitro. In this review, we sum up the therapeutic effect of herbal medicine in CKD via targeting mitochondrial function. This implies future strategies in preventing CKD.

Upregulation of miR-20b Protects Against Cerebral Ischemic Stroke by Targeting Thioredoxin Interacting Protein (TXNIP)

Dysregulation of microRNAs (miRNAs) is involved in abnormal development and pathophysiology in the brain. Although miR-20b plays essential roles in various human diseases, its function in cerebral ischemic stroke remains unclear. A cell model of oxygen glucose deprivation/reoxygenation (OGD/R) and A rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) were constructed. qRT-PCR and western blot were used to evaluate the expression of miR-20b and TXNIP. Cell viability was detected by MTT assay, and cell apoptosis was evaluated by flow cytometry. Targetscan and Starbase were used to predict the potential targets of miR-20b. Luciferase reporter assay was applied to determine the interaction between miR-20b and TXNIP. Rescue experiments were conducted to confirm the functions of miR-20b/TXNIP axis in cerebral ischemic stroke. MiR-20b was significantly downregulated after I/R both in vitro and in vivo. Upregulation of miR-20b inhibited OGD/R-induced neurons apoptosis and attenuated ischemic brain injury in rat model. Bioinformatic prediction suggested that TXNIP might be a target of miR-20b, and luciferase reporter assay revealed that miR-20b negatively regulated TXNIP expression by directly binding to the 3’-UTR of TXNIP. Downregulation of TXNIP inhibited OGD/R-induced neurons apoptosis in vitro and ischemic brain injury in vivo. Rescue experiments indicated that downregulation of TXNIP effectively reversed the effect of miR-20b inhibitor in neurons apoptosis after OGD/R-treatment and ischemic brain injury in a mouse model after MCAO/R-treatment. Our study demonstrated that upregulation of miR-20b protected the brain from ischemic brain injury by targeting TXNIP, extending our understanding of miRNAs in cerebral ischemic stroke.

Neuroprotective Effect of a New Free Radical Scavenger HL-008 in an Ischemia-Reperfusion Injury Rat Model

Oxidative stress plays a critical role in cerebral ischemia-reperfusion injury. We have previously developed a powerful antioxidant, HL-008. This study aimed to investigate the neuroprotective function of HL-008. HL-008 efficacy in vitro and in vivo was evaluated using a PC-12 cell oxidative stress model induced by hydrogen peroxide and a rat model of middle cerebral artery occlusion, respectively. The MTT assay was used to analyze cell viability. 2,3,5-Triphenyltetrazolium chloride and Hematoxylin and Eosin staining, immunofluorescence, western blot, and proteomics were used to evaluate the infarction volume, brain tissue morphology, apoptosis, inflammation, and related pathways. Indicators related to oxidative levels were also detected. HL-008 significantly reduced the cerebral infarction volume induced by ischemia-reperfusion, improved the neurological score, alleviated oxidative stress and inflammation in the brain tissue, reduced glial cell activation, inhibited brain tissue apoptosis by influencing multiple signaling pathways, and had a neuroprotective effect. If HL-008 is successfully developed, it could significantly improve stroke patients' quality of life.

Leonurine, a potential drug for the treatment of cardiovascular system and central nervous system diseases

Leonurus japonicus Houtt., a traditional Chinese herbal medicine, is often used as a gynecological medicine with the effect of promoting blood circulation, regulating menstruation, clearing heat, and detoxificating. As the most important alkaloid in L. japonicus, leonurine has a wide range of biological activities, such as antioxidation, anti-inflammation, and anti-apoptosis. Cardiovascular system and central nervous system diseases are arrogant killers that threaten human lives and health around the world, but many drugs for treating them have certain side effects. This paper reviews the potential therapeutic effects of leonurine on cardiovascular system and central nervous system diseases, summarizes the previous research progress, and focuses on its therapeutic effect in various diseases. Although leonurine plays a prominent role in the treatment of cardiovascular system and central nervous system diseases, there are still some shortages, such as low bioavailability, weak transmembrane ability, and poor fat solubility. Therefore, the structure modification of leonurine may solve these problems and provide reference value for the development of new drugs. At present, leonurine is in clinical trial, and it is hoped that our summary will help to provide guidance for its future research on the basic science and clinical application.

miR-204-3p/Nox4 Mediates Memory Deficits in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia in the elderly, and the mechanisms of AD are not fully defined. MicroRNAs (miRNAs) have been shown to contribute to memory deficits in AD. In this study, we identified that miR-204-3p was downregulated in the hippocampus and plasma of 6-month-old APPswe/PS1dE9 (APP/PS1) mice. miR-204-3p overexpression attenuated memory and synaptic deficits in APP/PS1 mice. The amyloid levels and oxidative stress were decreased in the hippocampus of APP/PS1 mice after miR-204-3p overexpression. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (Nox4) was a target of miR-204-3p, and Nox4 inhibition by GLX351322 protected neuronal cells against Aβ1-42-induced neurotoxicity. Furthermore, GLX351322 treatment rescued synaptic and memory deficits, and decreased oxidative stress and amyloid levels in the hippocampus of APP/PS1 mice. These results revealed that miR-204-3p attenuated memory deficits and oxidative stress in APP/PS1 mice by targeting Nox4, and miR-204-3p overexpression and/or Nox4 inhibition might be a potential therapeutic strategy for AD treatment.

Protection against acute cerebral ischemia/reperfusion injury by Leonuri Herba Total Alkali via modulation of BDNF-TrKB-PI3K/Akt signaling pathway in rats

OBJECTIVE

To observe the brain protective effect of Leonuri Herba Total Alkali (LHA) on cerebral ischemia reperfusion injury in rats, so as to provide basis for clinical research.

METHODS

Adult male SD rats were randomly assigned into sham group, middle cerebral artery occlusion/reperfusion (MCAO/R) group, and LHA + MCAO/R group (25 mg/kg, 50 mg/kg, and 100 mg/kg). Fourteen days before MCAO/R surgery, the rats in treatment groups were orally administered with LHA in ultrapure water once daily for 14 days, while rats in the sham and MCAO groups were given the same amount of saline in advance. After 1 h of administration on the 14th day, MCAO surgery was subjected. The neurological deficits, brain infarct volume, histopathology, immunofluorescence, inflammation indicators and the gene/protein expressions of BDNF-TrKB-PI3K/Akt signaling pathway in the rat brain tissue were evaluated 24 h after the MCAO/R-injury.

RESULTS

It was found that rats in LHA pre-administration group showed significantly reduced neurological deficit scores, infarction volume, the serum levels of NSE and S100β. Meanwhile, the content of Evans Blue (EB) in brain tissue from LHA group was decreased, as well as the levels of inflammatory cytokines and their gene levels. Moreover, LHA pre-administration inhibited the expression of CD44, GFAP, FOXO1 and promoted the expression of BDNF and NeuN. In addition, LHA pre-administration could up-regulate the protein expression of TrkB, p-PI3K, p-Akt, Bcl-2, and down-regulate the protein expression of Bax, and increase the level of Bcl-2/Bax.

CONCLUSIONS

The study demonstrated that LHA pre-administration could regulate the PI3K/Akt pathway by increasing BDNF levels, and play a neuroprotective role in cerebral ischemia-reperfusion injury.

Design and synthesis of novel SCM-198 analogs as cardioprotective agents: Structure-activity relationship studies and biological evaluations

SCM-198 (Leonurine) has attracted great attention due to its cardioprotective effects in myocardial infarction (MI). However, no systematic modifications and structure-activity relationship (SAR) studies could be traced so far. In this study, 35 analogs of SCM-198 were designed, synthesized and their cardioprotective effects were evaluated. The cell viability assay on cardiomyocyte cell line H9c2 challenged with H₂O₂ showed that several analogs exhibited more potent cytoprotective effects than SCM-198 at 1 μM and 10 μM concentrations. LDH release level in cells treated with 1 μM 14o was comparable with cells treated with 10 μM SCM-198. Results of Bcl-2 expression and caspase-3 activation accordingly indicated higher protective activity of 14o than SCM-198. Moreover, in a mouse model of MI, the mice pretreated with 14o had much lower infarct size compared with that of SCM-198. The mechanism study suggested that 14o improved cardiac morphology and reduced apoptosis of cardiomyocytes in the border zone of infarction, as proved by H&E and TUNEL staining.