Activation of the Nrf2/HO-1 signaling pathway contributes to the protective effects of baicalein against oxidative stress-induced DNA damage and apoptosis in HEI193 Schwann cells

Lactobacillus strains reduce the toxic effects of a subchronic exposure to arsenite through drinking water

The aim of the present study was to determine the efficacy of LAB strains in reducing the intestinal toxicity of arsenite [As(III)] and its tissue accumulation. For this purpose, Balb/c mice were randomly separated in four groups. One group received no treatment (control), one group received only As(III) (30 mg/L) via drinking water and the remaining two groups received As(III) via water and a daily dose of two LAB strains (Lactobacillus intestinalis LE1 and Lacticaseibacillus paracasei BL23) by gavage during 2 months. The results show that both strains reduce the pro-inflammatory and pro-oxidant response observed at the colonic level, partially restore the expression of the intercellular junction proteins (CLDN3 and OCLN) responsible for the maintenance of epithelial integrity, and increase the synthesis of the major mucin of the colonic mucus layer (MUC2), compared to animals treated with As(III) alone. Microbial metabolism of short-chain fatty acids also undergoes a recovery and the levels of fatty acids in the lumen reach values similar to those of untreated animals. All these positive effects imply the restoration of mucosal permeability, and a reduction of the marker of endotoxemia LPS binding protein (LBP). Treatment with the bacteria also has a direct impact on intestinal absorption, reducing the accumulation of As in the internal organs. The data suggest that the protective effect may be due to a reduced internalization of As(III) in intestinal tissues and to a possible antioxidant and anti-inflammatory activity of the bacteria through activation of pathways such as Nrf2 and IL-10. In vitro tests show that the protection may be the result of the combined action of structural and metabolic components of the LAB strains.

Cocoa flavanols, Nrf2 activation, and oxidative stress in peripheral artery disease: mechanistic findings in muscle based on outcomes from a randomized trial

The pathophysiology of muscle damage in peripheral artery disease (PAD) includes increased oxidant production and impaired antioxidant defenses. Epicatechin (EPI), a naturally occurring flavanol, has antioxidant properties that may mediate the beneficial effects of natural products such as cocoa. In a phase II randomized trial, a cocoa-flavanol-rich beverage significantly improved walking performance compared with a placebo in people with PAD. In the present work, the molecular mechanisms underlying the therapeutic effect of cocoa flavanols were investigated by analyzing baseline and follow-up muscle biopsies from participants. Increases in nuclear factor erythroid 2-related factor 2 (Nrf2) target antioxidants heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase [quinone] 1 (NQO1) in the cocoa group were significantly associated with reduced accumulation of central nuclei, a myopathy indicator, in type II muscle fibers (P = 0.017 and P = 0.023, respectively). Protein levels of the mitochondrial respiratory complex III subunit, cytochrome b-c1 complex subunit 2 (UQCRC2), were significantly higher in the cocoa group than in the placebo group (P = 0.032), and increases in UQCRC2 were significantly associated with increased levels of Nrf2 target antioxidants HO-1 and NQO1 (P = 0.001 and P = 0.035, respectively). Exposure of non-PAD human myotubes to ex vivo serum from patients with PAD reduced Nrf2 phosphorylation, an indicator of activation, increased hydrogen peroxide production and oxidative stress, and reduced mitochondrial respiration. Treatment of myotubes with EPI in the presence of serum from patients with PAD increased Nrf2 phosphorylation and protected against PAD serum-induced oxidative stress and mitochondrial dysfunction. Overall, these findings suggest that cocoa flavanols may enhance antioxidant capacity in PAD via Nrf2 activation.NEW & NOTEWORTHY The current study supports the hypothesis that in people with PAD, cocoa flavanols activate Nrf2, thereby increasing antioxidant protein levels, protecting against skeletal muscle damage, and increasing mitochondrial protein abundance. These results suggest that Nrf2 activation may be an important therapeutic target for improving walking performance in people with PAD.

Protective effects of scutellaria-coptis herb couple against non-alcoholic steatohepatitis via activating NRF2 and FXR pathways in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellaria-coptis herb couple (SC) is a classic herbal pair used in many Traditional Chinese Medicine (TCM) formulations in the treatment of endocrine and metabolic deseases. Diabetes mellitus and non-alcoholic steatohepatitis (NASH) are both endocrine and metabolic diseases. Previous studies have shown that SC has anti-diabetic effects. However, the effect and mechanism of SC against NASH remains unclear.

AIM OF THE STUDY

This study aimed to demonstrate the effect and mechanism of SC against NASH through the nuclear factor-erythroid 2-related factor 2 (Nrf2) and farnesoid X receptor (FXR) dual signaling pathways in vivo and in vitro.

MATERIALS AND METHODS

The high fat diet-fed rat model, and HepG2 and RAW264.7 cell models were used. Serum biochemical indexes and liver histopathological changes were examined. Metabolomics, transcriptomics, and flow cytometry were performed. RT-qPCR and western blot analysis were performed to provide expression of NRF2 and FXR pathway signal molecules during SC's anti-NASH treatment in vivo and in vitro.

RESULTS

SC had anti-NASH effects in vivo with significantly improvement of serum NASH biochemical index and hepatopathological structure; meanwhile, SC significantly elevated the expression levels of FXR protein in liver and intestinal tissues, and cholesterol 7a-hydroxylase (CYP7A1) protein in liver. The mRNA expression levels of Takeda G protein receptor 5 (TGR5), CYP7A1, fibroblast growth factor receptor-4 (FGFR4), FXR, small heterodimer partner (SHP), fibroblast growth factor 15/19 (FGF15/19) and glucagon-like peptide-1 (GLP-1) were significantly elevated by SC. SC reduced the levels of NorCA, isoLCA and α-MCA in the feces of NAFLD rats. In vitro, SC-containing serum (SC-CS) was found to significantly reduce intracellular lipid deposition, inhibit ROS production, reduce intracellular Malondialdehyde (MDA) and IL-1β levels, and enhance the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Six differential genes closely related to oxidative stress and Nrf2 were identified by transcriptomic analysis. SC-CS up-regulated the expression of NRF2, and reduced the expression of TXNIP and Caspase-1 genes in RAW264.7 cells. In addition, SC-CS reduced the expression of Keap1 and NF-κB, and up-regulated the expression of Nrf2, heme oxygenase-1 (HO-1), quinone oxidoreductase 1 (NQO1), and SOD; SC-CS elevated the protein level of NRF2, and reduced the protein level of TXNIP in HepG2 cells.

CONCLUSIONS

the mechanisms of SC action against NASH was closely related to the simultaneous activations of both NRF2 and FXR signaling pathways. These findings provide a new insight into the anti-NASH application of SC in clinical settings and demonstrate the potential of SC in the treatment of NASH.

Zn-Shik-PEG nanoparticles alleviate inflammation and multi-organ damage in sepsis

Sepsis is defined as a life-threatening organ dysfunction caused by excessive formation of reactive oxygen species (ROS) and dysregulated inflammatory response. Previous studies have reported that shikonin (Shik) possess prominent anti-inflammatory and antioxidant effects and holds promise as a potential therapeutic drug for sepsis. However, the poor water solubility and the relatively high toxicity of shikonin hamper its clinical application. To address this challenge, we constructed Zn2+-shikonin nanoparticles, hereafter Zn-Shik-PEG NPs, based on an organic-inorganic hybridization strategy of metal-polyphenol coordination to improve the aqueous solubility and biosafety of shikonin. Mechanistic studies suggest that Zn-Shik-PEG NPs could effectively clear intracellular ROS via regulating the Nrf2/HO-1 pathway, meanwhile Zn-Shik-PEG NPs could inhibit NLRP3 inflammasome-mediated activation of inflammation and apoptosis by regulating the AMPK/SIRT1 pathway. As a result, the Zn-Shik-PEG NPs demonstrated excellent therapeutic efficacies in lipopolysaccharide (LPS) as well as cecal ligation puncture (CLP) induced sepsis model. These findings suggest that Zn-Shik-PEG NPs may have therapeutic potential for the treatment of other ROS-associated and inflammatory diseases.

Inhibition of Indoxyl Sulfate-Induced Reactive Oxygen Species-Related Ferroptosis Alleviates Renal Cell Injury In Vitro and Chronic Kidney Disease Progression In Vivo

The accumulation of the uremic toxin indoxyl sulfate (IS) is a key pathological feature of chronic kidney disease (CKD). The effect of IS on ferroptosis and the role of IS-related ferroptosis in CKD are not well understood. We used a renal tubular cell model and an adenine-induced CKD mouse model to explore whether IS induces ferroptosis and injury and affects iron metabolism in the renal cells and the kidneys. Our results showed that exposure to IS induced several characteristics for ferroptosis, including iron accumulation, an impaired antioxidant system, elevated reactive oxygen species (ROS) levels, and lipid peroxidation. Exposure to IS triggered intracellular iron accumulation by upregulating transferrin and transferrin receptors, which are involved in cellular iron uptake. We also observed increased levels of the iron storage protein ferritin. The effects of IS-induced ROS generation, lipid peroxidation, ferroptosis, senescence, ER stress, and injury/fibrosis were effectively alleviated by treatments with an iron chelator deferoxamine (DFO) in vitro and the adsorbent charcoal AST-120 (scavenging the IS precursor) in vivo. Our findings suggest that IS triggers intracellular iron accumulation and ROS generation, leading to the induction of ferroptosis, senescence, ER stress, and injury/fibrosis in CKD kidneys. AST-120 administration may serve as a potential therapeutic strategy.

Study of Drug Target Identification and Associated Molecular Mechanisms for the Therapeutic Activity and Hair Follicle Induction of Two Ashwagandha Extracts Having Differential Withanolide Constitutions

Background

Ashwagandha extracts play a significant role in traditional Indian medicine to help treat a wide range of disorders from amnesia, erectile dysfunction, neurodegenerative and cardiovascular diseases, cancer, stress, anxiety, and many more. Ashwagandha root is enriched with bioactive plant metabolites of which withanolides are the most important ones. The concentration and constitution of withanolides primarily determine ashwagandha's potency and pharmacology. Various factors modulate the withanolide constitution in the plant-derived extracts, rendering inconsistent therapeutic efficacy. Standardisation of the extraction protocol and a better understanding of the pharmacology mechanism of different extracts with varied withanolide constitutions is therefore critical for developing reliable, repeatable, and effective ashwagandha-based treatment.

Objectives

Here, we work toward defining indication mechanisms for two varieties of ashwagandha extract-ASHWITH (ASH-Ext1) and Regenolide (ASH-Ext2)-with different proprietary withanolide proportions.

Methods

ASH-Ext1 was studied for antioxidant signaling modulation using HEK293, HeLa, and A549 cells, and ASH-Ext2 was studied for subcellular drug targets associated with the reactivation and longevity of human hair follicles, using primary human hair follicle dermal papilla cells (HFDPCs).

Results

Study findings support the antioxidant activity and Nrf2 signaling modulation by ASH-Ext1 in various cell models. Of note, ASH-Ext2 was found to increase β-catenin and telomerase reverse transcriptase (TERT) protein expression levels in HFDPCs.

Conclusion

The results of drug target modulation show us that the withanolide constitution associated with different extraction protocols influences the pharmacological potential of the extract significantly and points to the value of standardisation not only of total withanolide content but also of internal withanolide proportions.

New Insight on the Cytoprotective/Antioxidant Pathway Keap1/Nrf2/HO-1 Modulation by Ulva intestinalis Extract and Its Selenium Nanoparticles in Rats with Carrageenan-Induced Paw Edema

Currently, there is growing interest in exploring natural bioactive compounds with anti-inflammatory potential to overcome the side effects associated with the well-known synthetic chemicals. Algae are a rich source of bioactive molecules with numerous applications in medicine. Herein, the anti-inflammatory effect of Ulva intestinalis alone or selenium nanoparticles loaded with U. intestinalis (UISeNPs), after being fully characterized analytically, was investigated by a carrageenan-induced inflammation model. The pretreated groups with free U. intestinalis extract (III and IV) and the rats pretreated with UISeNPs (groups V and VI) showed significant increases in the gene expression of Keap1, with fold increases of 1.9, 2.27, 2.4, and 3.32, respectively. Similarly, a remarkable increase in the Nrf2 gene expression, with 2.09-, 2.36-, 2.59-, and 3.7-fold increases, was shown in the same groups, respectively. Additionally, the groups III, IV, V, and VI revealed a significantly increased HO-1 gene expression with a fold increase of 1.48, 1.61, 1.87, and 2.84, respectively. Thus, both U. intestinalis extract and the UISeNPs boost the expression of the cytoprotective/antioxidant pathway Keap1/Nrf2/HO-1, with the UISeNPs having the upper hand over the free extract. In conclusion, U. intestinalis and UISeNPs have proven promising anti-inflammatory activity through mediating different underlying mechanisms.

Pterosin sesquiterpenoids from Pteris laeta Wall. ex Ettingsh. protect cells from glutamate excitotoxicity by modulating mitochondrial signals

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Pteris (Pteridaceae) has been used as a traditional herb for a long time. In particular, Pteris laeta Wall. ex Ettingsh. has been widely used in traditional Chinese medicine to treat nervous system diseases and some pterosin sesquiterpenes from Pteris show neuroprotective activity, but their underlying molecular mechanisms remain elusive. Therefore, to investigate the neuroprotective activity and working mechanism of pterosin sesquiterpenes from P. laeta Wall. ex Ettingsh. will provide a better understanding and guidance in using P. laeta Wall. ex Ettingsh. as a traditional Chinese medicine.

AIM OF THE STUDY

We aim to develop effective treatments for neurodegenerative diseases from pterosin sesquiterpenes by evaluating their neuroprotective activity and investigating their working mechanisms.

MATERIALS AND METHODS

Primary screening on the glutamate-induced excitotoxicity cell model was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. Fluorescent-activated cell sorting (FACS) was used to analyze the activation level of glutamate receptors and mitochondria membrane potential after treatment. Transcriptomics and proteomics analysis was performed to identify possible targets of pterosin B. The key pathways were enriched by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis through the Database for Annotation, Visualization, and Integrated Discovery (DAVID). The core targets were visualized by a protein-protein interaction network using STRING. The mRNA and protein expressions were evaluated using real-time quantitative polymerase chain reaction (Q-PCR) and western blot, respectively. Immunocytochemistry was performed to monitor mitochondrial and apoptotic proteins. Cellular reactive oxygen species (ROS) were measured by ROS assay, and Ca²⁺ was stained with Fluo-4 AM to quantify intracellular Ca²⁺ levels.

RESULTS

We found pterosin B from Pteris laeta Wall. ex Ettingsh. showed significant neuroprotective activity against glutamate excitotoxicity, enhancing cell viability from 43.8% to 105% (p-value: <0.0001). We demonstrated that pterosin B worked on the downstream signaling pathways of glutamate excitotoxicity rather than directly blocking the activation of glutamate receptors. Pterosin B restored mitochondria membrane potentials, alleviated intracellular calcium overload from 107.4% to 95.47% (p-value: 0.0006), eliminated cellular ROS by 36.55% (p-value: 0.0143), and partially secured cells from LPS-induced inflammation by increasing cell survival from 46.75% to 58.5% (p-value: 0.0114). Notably, pterosin B enhanced the expression of nuclear factor-erythroid factor 2-related factor 2 (NRF2) and heme oxygenase-1 (HO-1) by 2.86-fold (p-value: 0.0006) and 4.24-fold (p-value: 0.0012), and down-regulated Kelch-like ECH-associated protein 1 (KEAP1) expression by 2.5-fold (p-value: 0.0107), indicating that it possibly promotes mitochondrial biogenesis and mitophagy to maintain mitochondria quality control and homeostasis, and ultimately inhibits apoptotic cell death.

CONCLUSIONS

Our work revealed that pterosin B protected cells from glutamate excitotoxicity by targeting the downstream mitochondrial signals, making it a valuable candidate for developing potential therapeutic agents in treating neurodegenerative diseases.

Alpha-lipoic acid supplementation corrects pathological alterations in cellular models of pantothenate kinase-associated neurodegeneration with residual PANK2 expression levels

BACKGROUND

Neurodegeneration with brain iron accumulation (NBIA) disorders are a group of neurodegenerative diseases that have in common the accumulation of iron in the basal nuclei of the brain which are essential components of the extrapyramidal system. Frequent symptoms are progressive spasticity, dystonia, muscle rigidity, neuropsychiatric symptoms, and retinal degeneration or optic nerve atrophy. One of the most prevalent subtypes of NBIA is Pantothenate kinase-associated neurodegeneration (PKAN). It is caused by pathogenic variants in the gene of pantothenate kinase 2 (PANK2) which encodes the enzyme responsible for the first reaction on the coenzyme A (CoA) biosynthesis pathway. Thus, deficient PANK2 activity induces CoA deficiency as well as low expression levels of 4'-phosphopantetheinyl proteins which are essential for mitochondrial metabolism.

METHODS

This study is aimed at evaluating the role of alpha-lipoic acid (α-LA) in reversing the pathological alterations in fibroblasts and induced neurons derived from PKAN patients. Iron accumulation, lipid peroxidation, transcript and protein expression levels of PANK2, mitochondrial ACP (mtACP), 4''-phosphopantetheinyl and lipoylated proteins, as well as pyruvate dehydrogenase (PDH) and Complex I activity were examined.

RESULTS

Treatment with α-LA was able to correct all pathological alterations in responsive mutant fibroblasts with residual PANK2 enzyme expression. However, α-LA had no effect on mutant fibroblasts with truncated/incomplete protein expression. The positive effect of α-LA in particular pathogenic variants was also confirmed in induced neurons derived from mutant fibroblasts.

CONCLUSIONS

Our results suggest that α-LA treatment can increase the expression levels of PANK2 and reverse the mutant phenotype in PANK2 responsive pathogenic variants. The existence of residual enzyme expression in some affected individuals raises the possibility of treatment using high dose of α-LA.

Preventive Effect of Pharmaceutical Phytochemicals Targeting the Src Family of Protein Tyrosine Kinases and Aryl Hydrocarbon Receptor on Environmental Stress-Induced Skin Disease

The skin protects our body; however, it is directly exposed to the environment and is stimulated by various external factors. Among the various environmental factors that can threaten skin health, the effects of ultraviolet (UV) and particulate matter (PM) are considered the most notable. Repetitive exposure to ultraviolet and particulate matter can cause chronic skin diseases such as skin inflammation, photoaging, and skin cancer. The abnormal activation of the Src family of protein tyrosine kinases (SFKs) and the aryl hydrocarbon receptor (AhR) in response to UV and/or PM exposure are involved in the development and aggravation of skin diseases. Phytochemicals, chemical compounds of natural plants, exert preventive effects on skin diseases through the regulation of various signaling pathways. Therefore, this review aims to highlight the efficacy of phytochemicals as potential nutraceuticals and pharmaceutical materials for the treatment of skin diseases, primarily by targeting SFK and AhR, and to explore the underlying mechanisms of action. Future studies are essential to validate the clinical potential for the prevention and treatment of skin diseases.

Baicalein Induces G2/M Cell Cycle Arrest Associated with ROS Generation and CHK2 Activation in Highly Invasive Human Ovarian Cancer Cells

Ovarian cancer is a lethal gynecological cancer because drug resistance often results in treatment failure. The CHK2, a tumor suppressor, is considered to be an important molecular target in ovarian cancer due to its role in DNA repair. Dysfunctional CHK2 impairs DNA damage-induced checkpoints, reduces apoptosis, and confers resistance to chemotherapeutic drugs and radiation therapy in ovarian cancer cells. This provides a basis for finding new effective agents targeting CHK2 upregulation or activation to treat or prevent the progression of advanced ovarian cancer. Here, the results show that baicalein (5,6,7-trihydroxyflavone) treatment inhibits the growth of highly invasive ovarian cancer cells, and that baicalein-induced growth inhibition is mediated by the cell cycle arrest in the G₂/M phase. Baicalein-induced G₂/M phase arrest is associated with an increased reactive oxygen species (ROS) production, DNA damage, and CHK2 upregulation and activation. Thus, baicalein modulates the expression of DNA damage response proteins and G₂/M phase regulatory molecules. Blockade of CHK2 activation by CHK2 inhibitors protects cells from baicalein-mediated G₂/M cell cycle arrest. All the results suggest that baicalein has another novel growth inhibitory effect on highly invasive ovarian cancer cells, which is partly related to G₂/M cell cycle arrest through the ROS-mediated DNA breakage damage and CHK2 activation. Collectively, our findings provide a molecular basis for the potential of baicalein as an adjuvant therapeutic agent in the treatment of metastatic ovarian cancer.

Inhibiting apoptosis of Schwann cell under the high-glucose condition: A promising approach to treat diabetic peripheral neuropathy using Chinese herbal medicine

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes. Glycemic control and lifestyle alterations cannot prevent the development of DPN; therefore, investigating effective treatments for DPN is crucial. Schwann cells (SCs) maintain the physiological function of peripheral nerves and promote the repair and regeneration of injured nerves. Inhibiting the apoptosis of SCs through various pathological pathways in a high-glucose environment plays an important role in developing DPN. Therefore, inhibiting the apoptosis of SCs can be a novel treatment strategy for DPN. Previous studies have indicated the potential of Chinese herbal medicine (CHM) in treating DPN. In this study, we have reviewed the effects of CHM (both monomers and extracts) on the apoptosis of SCs by interfering with the production of advanced glycation end products, oxidative stress, and endoplasmic reticulum stress pathological pathways. This review will demonstrate the potentialities of CHM in inhibiting apoptosis in SCs, providing new insights and perspectives for treating DPN.

3',4'-Dihydroxyflavone mitigates inflammatory responses by inhibiting LPS and TLR4/MD2 interaction

BACKGROUND

We previously reported the potential inhibitory activity of 3',4'-dihydroxyflavone (DHF) on nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in lipopolysaccharide (LPS)-stimulated macrophages.

PURPOSE

We investigated the underlying molecular mechanisms of DHF in LPS-activated macrophages and evaluated its effect on LPS-induced septic shock in mice.

METHODS

To explore the anti-inflammatory effect of DHF, nitrite, PGE₂, and cytokines were measured in vitro and in vivo experiments. In addition, to verify the molecular signaling pathway, quantitative real time-PCR, luciferase assay, nuclear extraction, electrophoretic mobility shift assay, immunocytochemistry, immunoprecipitation, molecular docking analysis, and myeloid differentiation 2 (MD2)-LPS binding assay were conducted.

RESULTS

DHF suppressed the LPS-induced expression of proinflammatory mediators through nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and interferon regulatory factor 3 (IRF3) inactivation pathways in RAW 264.7 macrophages. Importantly, molecular docking analysis and in vitro binding assays showed that DHF interacts with the hydrophobic pocket of MD2 and then interferes with the interaction between LPS and toll-like receptor 4 (TLR4). DHF inhibited LPS-induced oxidative stress by upregulating nuclear factor erythroid 2-related factor 2 (Nrf2). Treatment of LPS-induced endotoxemia mice with DHF reduced the expression levels of pro-inflammatory mediators via the inactivation of NF-κB, AP-1, and signal transducer and activator of transcription 1 (STAT1) in the lung tissue, thus increasing the survival rate.

CONCLUSION

Taken together, our data first time revealed the underlying mechanism of the DHF-dependent anti-inflammatory effect by preventing LPS from binding to the TLR4/MD2 complex. Therefore, DHF may be a possible anti-inflammatory agent for the treatment of LPS-mediated inflammatory diseases.

Transcription factor Nrf2 as a potential therapeutic target for COVID-19

The coronavirus disease 2019 (COVID-19) is caused by a novel severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2). Critically ill patients with SARS-COV-2 infection frequently exhibit signs of high oxidative stress and systemic inflammation, which accounts for most of the mortality. Antiviral strategies to inhibit the pathogenic consequences of COVID-19 are urgently required. The nuclear factor erythroid 2-related transcription factor (Nrf2) is a transcription factor that is involved in antioxidant and anti-inflammatory defense in several tissues and cells. This review tries to present an overview of the role of Nrf2 in the treatment of COVID-19.

Ginsenoside ompound K reduces neuronal damage and improves neuronal synaptic dysfunction by targeting Aβ

Background: Alzheimer's disease (AD) is the most common neurodegenerative condition worldwide, with amyloid ß (Aβ) fibrils presenting as its main pathological feature. This study investigated whether Ginsenoside Compound K (CK) has activity against Aβ and its mechanism in reducing synaptic damage and cognitive impairment. Methods: The binding capacity of CK to Aβ42 and Nrf2/Keap1 was determined using molecular docking. Transmission electron microscopy was used to monitor CK-mediated degradation of Aβ fibrils. The effect of CK on the survival of Aβ42-damaged HT22 cells was determined using a CCK-8 assay. The therapeutic efficacy of CK in a scopoletin hydrobromide (SCOP) induced cognitive dysfunction mouse model was measured using a step-down passive avoidance test. GO enrichment analysis of mouse brain tissue was peformed using Genechip. Hydroxyl radical scavenging and reactive oxygen species assays were performed to verify the antioxidant activity of CK. The effects of CK on the expression of Aβ42, the Nrf2/Keap1 signaling pathway, and other proteins were determined by western blotting, immunofluorescence, and immunohistochemistry. Results: Molecular docking results showed that CK interacts with Lys16 and Glu3 of Aβ42. CK reduced the aggregation of Aβ42 as observed using transmission electron microscopy. CK increased the level of insulin-degrading enzyme and decreased the levels ß-secretase and γ-secretase; therefore, it can potentially inhibit the accumulation of Aβ in neuronal extracellular space in vivo. CK improved cognitive impairment and increased postsynaptic density protein 95 and synaptophysin expression levels in mice with SCOP-induced cognitive dysfunction. Further, CK inhibited the expression of cytochrome C, Caspase-3, and cleaved Caspase-3. Based on Genechip data, CK was found to regulate molecular functions such as oxygen binding, peroxidase activity, hemoglobin binding, and oxidoreductase activity, thus affecting the production of oxidative free radicals in neurons. Further, CK regulated the expression of the Nrf2/Keap1 signaling pathway through its interaction with the Nrf2/Keap1 complex. Conclusion: Our findings show that CK regulates the balance between Aβ monomers production and clearance, CK binds to Aβ monomer to inhibits the accumulation of Aβ, increases the level of Nrf2 in neuronal nuclei, reduces oxidative damage of neurons, improves synaptic function, thus ultimately protecting neurons.

The loss of pancreatic islet NADPH oxidase (NOX)2 improves islet transplantation

Islet transplantation is a promising treatment strategy for type 1 diabetes mellitus (T1DM) patients. However, oxidative stress-induced graft failure due to an insufficient revascularization is a major problem of this therapeutic approach. NADPH oxidase (NOX)2 is an important producer of reactive oxygen species (ROS) and several studies have already reported that this enzyme plays a crucial role in the endocrine function and viability of β-cells. Therefore, we hypothesized that targeting islet NOX2 improves the outcome of islet transplantation. To test this, we analyzed the cellular composition and viability of isolated wild-type (WT) and Nox2-/- islets by immunohistochemistry as well as different viability assays. Ex vivo, the effect of Nox2 deficiency on superoxide production, endocrine function and anti-oxidant protein expression was studied under hypoxic conditions. In vivo, we transplanted WT and Nox2-/- islets into mouse dorsal skinfold chambers and under the kidney capsule of diabetic mice to assess their revascularization and endocrine function, respectively. We found that the loss of NOX2 does not affect the cellular composition and viability of isolated islets. However, decreased superoxide production, higher glucose-stimulated insulin secretion as well as expression of nuclear factor erythroid 2-related factor (Nrf)2, heme oxygenase (HO)-1 and superoxide dismutase 1 (SOD1) was detected in hypoxic Nox2-/- islets when compared to WT islets. Moreover, we detected an early revascularization, a higher take rate and restoration of normoglycemia in diabetic mice transplanted with Nox2-/- islets. These findings indicate that the suppression of NOX2 activity represents a promising therapeutic strategy to improve engraftment and function of isolated islets.

The suppressive role of phytochemical-induced glutathione S-transferase Mu 2 in human urothelial carcinoma cells

Glutathione S-transferases (GSTs) belong to one class of phase 2 detoxification enzymes which are important in metabolism and/or detoxification of various electrophilic endogenous metabolites and xenobiotics. From the available database, we found that GSTM2 gene expression is lower in high stages of bladder urothelial carcinoma than in stage 1 and normal bladder tissue. GSTM2 overexpression retards invasion, migration and tumor sphere formation of bladder cancer cells. Analysis of GSTM2 promoter activity shows that one SP1 site located at - 48 to - 40 bp is important for GSTM2 gene expression in BFTC 905 cells. An SP1 inhibitor, mithramycin A, inhibits GSTM2 promoter activity and protein expression. SP1 overexpression also increases GSTM2 expression in BFTC 905 and 5637 cells. Eight potential phytochemicals were analyzed for GSTM2 promoter activation, and results indicated that baicalein, berberrubine, chalcone, curcumin, resveratrol, and wogonin can increase promoter activity. In endogenous GSTM2 expression, berberrubine and resveratrol activated GSTM2 mRNA and protein expression the most. A DNA methylation inhibitor, 5-aza-deoxycytidine, can decrease GSTM2 gene methylation level and then increase its gene expression; 50 μM berberrubine decreased the GSTM2 gene methylation level, providing a mechanism for activating GSTM2 gene expression. Berberrubine and resveratrol also increased SP1 protein expression as one of the mechanisms for GSTM2 gene expression. In summary, berberrubine and resveratrol activates GSTM2 expression which inhibits cell proliferation, migration, and invasion of bladder cancer cells. The GSTM2 expression mechanism is partially via SP1 activation, and the effect of berberrubine is also partly via DNA CpG demethylation.

Scutellaria baicalensis and its constituents baicalin and baicalein as antidotes or protective agents against chemical toxicities: a comprehensive review

Scutellaria baicalensis (SB), also known as the Chinese skullcap, has a long history of being used in Chinese medicine to treat a variety of conditions ranging from microbial infections to metabolic syndrome and malignancies. Numerous studies have reported that treatment with total SB extract or two main flavonoids found in its root and leaves, baicalin (BA) and baicalein (BE), can prevent or alleviate the detrimental toxic effects of exposure to various chemical compounds. It has been shown that BA and BE are generally behind the protective effects of SB against toxicants. This paper aimed to review the protective and therapeutic effects of SB and its main components BA and BE against chemical compounds that can cause intoxication after acute or chronic exposure and seriously affect different vital organs including the brain, heart, liver, and kidneys. In this review paper, we had a look into a total of 221 in vitro and in vivo studies from 1995 to 2021 from the scientific databases PubMed, Scopus, and Web of Science which reported protective or therapeutic effects of BA, BE, or SB against drugs and chemicals that one might be exposed to on a professional or accidental basis and compounds that are primarily used to simulate disease models. In conclusion, the protective effects of SB and its flavonoids can be mainly attributed to increase in antioxidants enzymes, inhibition of lipid peroxidation, reduction of inflammatory cytokines, and suppression of apoptosis pathway.

A novel approach to type 3 diabetes mechanism: The interplay between noncoding RNAs and insulin signaling pathway in Alzheimer's disease

Today, growing evidence indicates that patients with type 2 diabetes (T2D) are at a higher risk of developing Alzheimer's disease (AD). Indeed, AD as one of the main causes of dementia in people aged more than 65 years can be aggravated by insulin resistance (IR) and other metabolic risk factors related to T2D which are also linked to the function of the brain. Remarkably, a new term called "type 3 diabetes" has been suggested for those people who are diagnosed with AD while also showing the symptoms of IR and T2D. In this regard, the role of genetic and epigenetic changes associated with AD has been confirmed by many studies. On the other hand, it should be noted that the insulin signaling pathway is highly regulated by various mechanisms, including epigenetic factors. Among these, the role of noncoding RNAs (ncRNAs), including microRNAs and long noncoding RNAs has been comprehensively studied with respect to the pathology of AD and the most well-known underlying mechanisms. Nevertheless, the number of studies exploring the association between ncRNAs and the downstream targets of the insulin signaling pathway in the development of AD has notably increased in recent years. With this in view, the present study aimed to review the interplay between different ncRNAs and the insulin signaling pathway targets in the pathogenesis of AD to find a new approach in the field of combining biomarkers or therapeutic targets for this disease.

Methylsulfonylmethane relieves cobalt chloride-induced hypoxic toxicity in C2C12 myoblasts

AIMS

In biology and medicine, hypoxia refers to reduced oxygen tension or oxygen starvation resulting from various environmental or pathological conditions. Prolonged hypoxia may lead to an imbalance in protein production and a loss of muscle mass in animals. The physiological response to hypoxia includes oxidative stress-induced activation of complex cell-signaling networks such as hypoxia-inducible factor (HIF), phosphoinositide 3-kinase (PI3K), and Janus kinase/signal transducer and activator of transcription (JAK-STAT). Methylsulfonylmethane (MSM) is a natural sulfur compound that regulates HIF-1α expression and provides cytoprotection from oxidative stress. In this study, we explored the anti-hypoxic activity and cytoprotective effect of MSM in cobalt chloride (CoCl₂)-induced hypoxic C2C12 mouse myoblast culture.

MATERIALS AND METHODS

We used western blotting, real time PCR, flow cytometry for molecular signaling studies and we also used MTT assay and ChIP assay along with comet assay for cellular processes.

KEY FINDINGS

MSM prevented the CoCl₂ induced cytotoxicity. Molecular markers of hypoxia, induced by CoCl₂, were normalized or reduced by MSM, which also inhibited the effect of CoCl₂-induced JAK2/STAT5b/Cyclin D1 and PI3K/AKT signaling. CoCl₂-induced oxidative stress results in activation of the NRF2/HO-1-mediated cell survival pathway and inhibition of DNA repair, both of which were prevented by MSM.

SIGNIFICANCE

We suggest MSM can be considered as a candidate drug for reducing the effects of hypoxia in both animals and humans.

Molecular Targets of Brown Algae Phlorotannins for the Therapy of Inflammatory Processes of Various Origins

Inflammatory reactions are part of a complex biological response that plays a vital role in the appearance of various stimuli resulting from tissue and cell damage, the invasion of pathogenic bacteria, and the formation of the subsequent adaptive immune response. The production of many triggers and mediators of inflammation, which are inducers of pro-inflammatory factors, is controlled by numerous differentiation programs, through which inflammation is resolved and tissue homeostasis is restored. However, prolonged inflammatory responses or dysregulation of pro-inflammatory mechanisms can lead to chronic inflammation. Modern advances in biotechnology have made it possible to characterize the anti-inflammatory activity of phlorotannins, polyphenolic compounds from brown seaweed, and the mechanisms by which they modulate the inflammatory response. The purpose of this review is to analyze and summarize the results of numerous experimental in vitro and in vivo studies, illustrating the regulatory mechanisms of these compounds, which have a wide range of biological effects on the body. The results of these studies and the need for further research are discussed.

Activation of the Nrf2 Pathway as a Therapeutic Strategy for ALS Treatment

Amyotrophic lateral sclerosis is a progressive and fatal disease that causes motoneurons degeneration and functional impairment of voluntary muscles, with limited and poorly efficient therapies. Alterations in the Nrf2-ARE pathway are associated with ALS pathology and result in aberrant oxidative stress, making the stimulation of the Nrf2-mediated antioxidant response a promising therapeutic strategy in ALS to reduce oxidative stress. In this review, we first introduce the involvement of the Nrf2 pathway in the pathogenesis of ALS and the role played by astrocytes in modulating such a protective pathway. We then describe the currently developed activators of Nrf2, used in both preclinical animal models and clinical studies, taking into consideration their potentialities as well as the possible limitations associated with their use.

BaZiBuShen alleviates cognitive deficits and regulates Sirt6/NRF2/HO-1 and Sirt6/P53-PGC-1α-TERT signaling pathways in aging mice

ETHNOPHARMACOLOGICAL RELEVANCE

BaZiBuShen formula (BZBS) is clinically used to counteract mental fatigue and to retard the aging process. Brain aging echoes in major risks of human sufferings and has become one of the main challenges to our societies and the health-care systems.

AIM OF THE STUDY

To investigate the effect and mode of action of BZBS on aging-associated cognitive impairments.

MATERIALS AND METHODS

BZBS was orally administered to D-galactose and NaNO2-induced aging mice. Premature senescence was assessed using the Morris water maze, step-down type passive avoidance, and pole-climbing tests. Telomere length was examined by qPCR analysis. Telomerase activity was assessed using PCR ELISA assay. Mitochondrial complex IV activity was examined by biochemical test. The levels of redox and immune status were determined by ELISA or biochemical assay. The expressions of sirtuin 6 (Sirt6), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), P53, telomerase reverse transcriptase (TERT), heme oxygenase-1 (HO-1), phospho(p)-nuclear factor erythroid-2 related factor 2 (NRF2), caspase-3, Bcl-2 associated x (Bax), and B-cell lymphoma-2 (Bcl-2) in the cerebral cortex were examined by Western blot and/or immunohistochemical staining.

RESULTS

BZBS intervention ameliorated reduced brain performances in aging mice, including memory, cognitive, and motor functions. In addition, BZBS administration to aging mice preserved redox homeostasis, attenuated immunosenescence, and maintained telomerase activity and telomere length. Moreover, BZBS treatment were associated with a declines in P53, caspase-3, Bax expressions and an increase in Sirt6, p-HO-1, p-NRF2, PGC-1α, and Bcl-2 expressions in the brains of this rapid aging mouse.

CONCLUSIONS

BZBS attenuates premature senescence possibly via the preservation of redox homeostasis and telomere integrity, and inhibition of apoptosis in rapid aging mouse. The mechanism governing the alterations may be associated with through the activation of Sirt6/NRF2/HO-1 and Sirt6/P53-PGC-1α-TERT signaling pathways. The results suggest that BZBS may provide a novel strategy for confronting aging and age-associated diseases.

Grub polypeptide extracts protect against oxidative stress through the NRF2-ARE signaling pathway

Grub polypeptide extracts (GPEs) have antioxidant effects; however, their underlying molecular mechanisms are unknown. This study explored the antioxidant molecular mechanism of GPE via the nuclear factor-erythroid 2-related factor 2 (NRF2)-antioxidant response element (ARE) signaling pathway in C2C12 muscle satellite cells exposed to oxidative stress. The effects of GPE/or H2O2 on C2C12 were investigated by the MTT (3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) viability assay and immunofluorescence and small interfering RNA (siRNA) analyses. The cell viability, cell damage, intracellular reactive oxygen species (ROS) levels, and NRF2 signaling pathways related to proteins were measured. GPE significantly increased the antioxidant capacity of cells, evident by increased cell viability and decreased lactate dehydrogenase leakage, DNA damage, malondialdehyde content, and ROS level. GPE also markedly increased mRNA expression levels and activities of antioxidant enzymes including superoxidase 1 and 2, catalase, and glutathione peroxidase. In addition, GPE increased the gene and protein expression of NRF2 and heme oxygenase 1 by promoting NRF2 translocation from the cytoplasm to the nucleus and activating NRF2-ARE signaling pathways. The antioxidant effects of GPE through these signaling pathways were further confirmed by NRF2-specific siRNA silencing. Thus, GPE enhances antioxidant capacity and alleviates oxidative damage of C2C12 cells via the NRF2-ARE signaling pathway.

In vitro evaluation of nanoplastics using human lung epithelial cells, microarray analysis and co-culture model

Nanoplastics, including polystyrene nanoplastics (PS-NPs), are widely existed in the atmosphere, which can be directly and continuously inhaled into the human body, posing a serious threat to the respiratory system. Therefore, it is urgent to estimate the potential pulmonary toxicity of airborne NPs and understand its underlying mechanism. In this research, we used two types of human lung epithelial cells (bronchial epithelium transformed with Ad12-SV40 2B, BEAS-2B) and (human pulmonary alveolar epithelial cells, HPAEpiC) to investigate the association between lung injury and PS-NPs. We found PS-NPs could significantly reduce cell viability in a dose-dependent manner and selected 7.5, 15 and 30 μg/cm² PS-NPs as the exposure dosage levels. Microarray detection revealed that 770 genes in the 7.5 μg/cm² group and 1951 genes in the 30 μg/cm² group were distinctly altered compared to the control group. Function analysis suggested that redox imbalance might play central roles in PS-NPs induced lung injury. Further experiments verified that PS-NPs could break redox equilibrium, induce inflammatory effects, and triggered apoptotic pathways to cause cell death. Importantly, we found that PS-NPs could decrease transepithelial electrical resistance by depleting tight junctional proteins. Result also demonstrated that PS-NPs-treated cells increased matrix metallopeptidase 9 and Surfactant protein A levels, suggesting the exposure of PS-NPs might reduce the repair ability of the lung and cause tissue damage. In conclusion, nanoplastics could induce oxidative stress and inflammatory responses, followed by cell death and epithelial barrier destruction, which might result in tissue damage and lung disease after prolonged exposure.

Quercetin with lycopene modulates enzymic antioxidant genes pathway in isoproterenol cardiotoxicity in rats

Quercetin (QN) is a naturally occurring phenolic compound found largely in vegetables and fruits. Lycopene (LY) is yet another natural phytocompound, found abundantly in red-colored fruits and vegetables. Both have been reported to have beneficial activities in humans. In this study, we document in vivo experimental model for isoproterenol (ISO) cardiac injury toxicity in Sprague-Dawley (SD) rats and treatment with a combined optimized concentration of quercetin and lycopene (QL). Male SD rats of different groups were treated with QL (80 mg/kg QN and 3 mg/kg LY together p.o.) for 10 days with ISO administration (100 mg/kg i.p.) on days 7 and 8. After experimental period, CK-MB, TROP, AST, ALT, LDH, GST, GPx, CAT, SOD, Vit.E, Vit. C, GSH, GSSG and MDA were estimated. SD rats administered with ISO showed an obvious rise in the serum marker enzyme levels and tissue oxidative stress markers (MDA and GSSG). Furthermore, marked reductions in the body weight and increases enzymic and non-enzymic antioxidant levels were noticed. Histological features of the heart also indicated a disruption in the cardiac myofibrils structure of ISO-intoxicated rats. Also, quantitative PCR analysis revealed an involvement of antioxidant and related pathway genes such as Nrf2, HO-1, NQO1, GSTµ, SOD1, SOD2, CAT and BCl-2 genes. QL pretreatment prevented all these adverse effects of ISO cardiotoxicity and significantly reduced the myocardial damage. Decrease in oxidative stress was observed, possibly through alterations in the expression levels of enzymic antioxidant genes (GSTµ, SOD1, SOD2 and CAT). In general, QL exert a strong protective effect through the modulations in enzymic antioxidant activity and associated molecular pathways-regulating effect in cardiovascular disease.

PIAS3 suppresses damage in an Alzheimer's disease cell model by inducing the STAT3-associated STAT3/Nestin/Nrf2/HO-1 pathway

BACKGROUND

Alzheimer's disease (AD), the most common form of dementia, is caused by the degeneration of the central nervous system (CNS). A previous study reported that signal transducer and activator of transcription 3 (STAT3) is activated during AD development; nonetheless, the related mechanism remains unknown. Thus, this study used a cell model to explore whether and how the protein inhibitor of activated STAT3 (PIAS3) is involved in AD development.

METHODS

Cerebrospinal fluid (CSF) specimens of 30 patients with AD and 10 normal participants were included in this study. SH-SY5Y cells were used to constructed AD model. Relevant indices were then detected and analyzed.

RESULTS

The results showed that compared with the control group, PIAS3 expression was substantially decreased in patients with AD and amyloid beta (Aβ)-treated SH-SY5Y cells. PIAS3 overexpression was able to reverse the detrimental effects of Aβ treatment on cell survival and growth. Further, it could also ameliorate apoptosis and oxidative stress in Aβ-treated SH-SY5Y cells. Additionally, PIAS3 was shown to reduce the activated form of STAT3 and increase the activity of the downstream Nestin/nuclear factor erythroid 2-related factor/heme oxygenase-1 pathway.

CONCLUSIONS

STAT3 reactivation by colivelin treatment negated the influence of PIAS3 on the survival, growth, apoptosis, and oxidative stress of Aβ-treated SH-SY5Y cells.

The Role of Nutritional Lifestyle and Physical Activity in Multiple Sclerosis Pathogenesis and Management: A Narrative Review

Studies on the role of nutritional factors and physical activity (PA) in the pathogenesis of multiple sclerosis (MS) go back a long time. Despite the intrinsic difficulty of studying their positive or negative role in MS, the interest of researchers on these topics increased during the last few decades, since the role of diet has been investigated with the perspective of the association with disease-modifying drugs (DMD). The association of DMD, diets, and PA might have an additive effect in modifying disease severity. Among the various diets investigated (low-carbohydrate, gluten-free, Mediterranean, low-fat, fasting-mimicking, and Western diets) only low-carbohydrate, Mediterranean, and fast-mimicking diets have shown both in animal models and in humans a positive effect on MS course and in patient-reported outcomes (PROs). However, the Mediterranean diet is easier to be maintained compared to fast-mimicking and low-carbohydrate diets, which may lead to detrimental side effects requiring careful clinical monitoring. Conversely, the Western diet, which is characterized by a high intake of highly saturated fats and carbohydrates, may lead to the activation of pro-inflammatory immune pathways and is therefore not recommended. PA showed a positive effect both in animal models as well as on disease course and PROs in humans. Training with combined exercises is considered the more effective approach.

Study on constituents of Scutellaria nepetifolia as a potent source of phytochemicals with NO inhibitory effect

Based on the long history of Scutellaria plants in east traditional medicines, several species of Scutellaria showed promising antioxidant, anti-inflammation and neuroprotection effects in pharmacological researches. Using bioassay-guided fractionation of various extract of Scutellaria nepetifolia, an endemic species that grows widely in Iran, based on on nitric oxide (NO) inhibitory activity against H₂O₂ induced NO production in PC12 pheochromocytoma cells led to the isolation of two iridoid compounds namely, as 6β-hydroxy 8-epiboshnaloside (1) and 1,5,9-epideoxy loganic acid (2) and Verbascoside (3). Finally, the interaction of isolated compounds with inducible nitric oxide synthase (iNOS) protein was simulated by molecular docking study. It is the first report of these two iridoid glycosides from Scutellaria spp. All three isolated compounds showed strong interaction with iNOS enzyme in molecular docking simulations. So, they possibly contributed in the NO inhibitory effect of S. nepetifolia.

Crosstalk between AdipoR1/AdipoR2 and Nrf2/HO-1 signal pathways activated by β-caryophyllene suppressed the compound 48/80 induced pseudo-allergic reactions

Mast cell activation is initiated by two signaling pathways: Immunoglobulin E (IgE) dependent and IgE independent pathway. It is reported that the IgE-independent type or pseudo-allergy pathway gets activated by G-protein-dependent activation of the mast cell. Recently, adiponectin (APN) receptors, AdipoR1, and AdipoR2 are identified as G-protein-coupled receptors (GPCRs). Interestingly, APN replenishment is reported to activate the Nrf2/HO-1 signaling axis. However, no study has been performed interlinking the role of APN and Nrf2/HO-1 signaling axis in pseudo-allergic reaction. In the present study, we evaluated the anti-pseudo-allergic effects of β-caryophyllene, an FDA approved food additive, in activating AdipoR1/AdipoR2 and Nrf2/HO-1 axis signaling pathway. Compound 48/80 (C48/80) induced systemic and cutaneous anaphylaxis-like shock in BALB/c mice was performed to assess the efficacy of BCP. To assess the effect of BCP in anaphylactic hypotension, mean arterial pressure was measured in Wistar rats. Inhibitory properties of BCP in mast cell degranulation were estimated in rat peritoneal mast cells (RPMCs). ELISA was performed to estimate IL-6, TNF, IL-1β, IgE, OVA-IgE and APN and western blotting for protein expression of Nrf2/HO-1 and AdipoR1-AdipoR2. BCP dose-dependently inhibited systemic and cutaneous anaphylaxis-like shock induced by C48/80. BCP dose-dependently inhibited the mast cell degranulation followed by inhibition of histamine release as well as BCP dose-dependently activated the Nrf2/HO-1 and AdipoR1-AdipoR2 signaling axis pathway. Moreover, BCP reverses the drop-in blood pressure when the hemodynamic parameters were accessed. Our findings suggest that BCP is a potent AdipoR1/AdipoR2-Nrf2/HO-1 axis pathway agonist that may suppress the IgE-independent pathway towards allergic response to secretagogues.

Metformin attenuates rotenone-induced oxidative stress and mitochondrial damage via the AKT/Nrf2 pathway

Oxidative stress and mitochondrial dysfunction are now widely accepted as the major factors involved in the pathogenesis of Parkinson's disease (PD). Rotenone, a commonly used environmental toxin also reproduces these principle pathological features of PD. Hence, it is used frequently to induce experimental PD in cells and animals. In this study, we evaluated the neuroprotective effects of metformin against rotenone-induced toxicity in SH-SY5Y cells. Metformin treatment clearly rescued these cells from rotenone-mediated cell death via the reduction of the cytosolic and mitochondrial levels of reactive oxygen species and restoration of mitochondrial function. Furthermore, metformin upregulated PGC-1α, the master regulator of mitochondrial biogenesis and key antioxidant molecules, including glutathione and superoxide dismutase. We demonstrated that the drug exerted its cytoprotective effects by activating nuclear factor erythroid 2-related factor 2 (Nrf2)/heme-oxygenase (HO)-1 pathway, which in turn, is dependent on AKT activation by metformin. Thus, our results implicate that metformin provides neuroprotection against rotenone by inhibiting oxidative stress in the cells by inducing antioxidant system via upregulation of transcription mediated by Nrf2, thereby restoring the rotenone-induced mitochondrial dysfunction and energy deficit in the cells.

The Protective Effect of Aspirin Eugenol Ester on Oxidative Stress to PC12 Cells Stimulated with H2O2 through Regulating PI3K/Akt Signal Pathway

Aspirin eugenol ester (AEE) is a new pharmaceutical compound esterified by aspirin and eugenol, which has anti-inflammatory, antioxidant, and other pharmacological activities. This study is aimed at identifying the protective effect of AEE against H₂O₂-induced apoptosis in rat adrenal pheochromocytoma PC12 cells and the possible mechanisms. The results of cell viability assay showed that AEE could increase the viability of PC12 cells stimulated by H₂O₂, while AEE alone had no significant effect on the viability of PC12 cells. Compared with the control group, the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were significantly decreased, and the content of malondialdehyde (MDA) was significantly increased in the H₂O₂ group. By AEE pretreatment, the level of MDA was reduced and the levels of SOD, CAT, and GSH-Px were increased in H₂O₂-stimulated PC12 cells. In addition, AEE could reduce the apoptosis of PC12 cells induced by H₂O₂ via reducing superoxide anion, intracellular ROS, and mitochondrial ROS (mtROS) and increasing the levels of mitochondrial membrane potential (ΔΨm). Furthermore, the results of western blotting showed that compared with the control group, the expression of p-PI3K, p-Akt, and Bcl-2 was significantly decreased, while the expression of Caspase-3 and Bax was significantly increased in the H₂O₂ group. In the AEE group, AEE pretreatment could upregulate the expression of p-PI3K, p-Akt, and Bcl-2 and downregulate the expression of Caspase-3 and Bax in PC12 cells stimulated with H₂O₂. The silencing of PI3K with shRNA and its inhibitor-LY294002 could abrogate the protective effect of AEE in PC12 cells. Therefore, AEE has a protective effect on H₂O₂-induced PC12 cells by regulating the PI3K/Akt signal pathway to inhibit oxidative stress.

Inhibition of Oxidative Stress and ALOX12 and NF-κB Pathways Contribute to the Protective Effect of Baicalein on Carbon Tetrachloride-Induced Acute Liver Injury

This study investigates the protective effect of baicalein on carbon tetrachloride (CCl₄)-induced acute liver injury and the underlying molecular mechanisms. Mice were orally administrated baicalein at 25 and 100 mg/kg/day for 7 consecutive days or ferrostatin-1 (Fer-1) at 10 mg/kg was i.p. injected in mice at 2 and 24 h prior to CCl₄ injection or the vehicle. Our results showed that baicalein or Fer-1 supplementation significantly attenuated CCl₄ exposure-induced elevations of serum alanine aminotransferase and aspartate aminotransferase, and malondialdehyde levels in the liver tissues and unregulated glutathione levels. Baicalein treatment inhibited the nuclear factor kappa-B (NF-κB) pathway, activated the erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway in liver tissues, and markedly improved CCl₄-induced apoptosis, inflammation and ferroptosis in liver tissues exposed with CCl₄. In vitro, baicalein treatment improved CCl₄ -induced decreases of cell viabilities and knockdown of Nrf2 and arachidonate 12-lipoxygenase (ALOX12) genes partly abolished the protective effect of baicalein on CCl₄ -induced cytotoxicity in HepG2 cells. In conclusion, our results reveal that baicalein supplementation ameliorates CCl₄-induced acute liver injury in mice by upregulating the antioxidant defense pathways and downregulating oxidative stress, apoptosis, inflammation and ferroptosis, which involved the activation of Nrf2 pathway and the inhibition of ALOX12 and NF-κB pathways.

Effects of Traditional Chinese Medication-Based Bioactive Compounds on Cellular and Molecular Mechanisms of Oxidative Stress

The oxidative stress reaction is the imbalance between oxidation and antioxidation in the body, resulting in excessive production of oxygen free radicals in the body that cannot be removed, leading to excessive oxidation of the body, and causing damage to cells and tissues. A large number of studies have shown that oxidative stress is involved in the pathological process of many diseases, so inhibiting oxidative stress, that is, antioxidation, is of great significance for the treatment of diseases. Studies have shown that many traditional Chinese medications contain antioxidant active bioactive compounds, but the mechanisms of those compounds are different and complicated. Therefore, by summarizing the literature on antioxidant activity of traditional Chinese medication-based bioactive compounds in recent years, our review systematically elaborates the main antioxidant bioactive compounds contained in traditional Chinese medication and their mechanisms, so as to provide references for the subsequent research.

Effects of Huangqin Decoction on ulcerative colitis by targeting estrogen receptor alpha and ameliorating endothelial dysfunction based on system pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqin Decoction (HQD), a traditional Chinese medicinal (TCM) formula chronicled in Shang Han Lun, has been used to treat gastrointestinal diseases for nearly 1800 years.

OBJECTIVE

To investigate the effects and underlying mechanisms of HQD on ulcerative colitis (UC).

METHODS

The bioactive compounds in HQD were obtained from the traditional Chinese medicine systems pharmacology database. Then, the HQD and UC-related targets were analyzed by establishing HQD-Compounds-Targets (H-C-T) and protein-protein interaction (PPI) networks. Enrichment analysis was used for further study. The candidate targets for the effects of HQD on UC were validated using a dextran sulfate sodium-induced UC mouse experiment.

RESULTS

The results showed that 51 key targets were gained by matching 284 HQD-related targets and 837 UC-related targets. Combined with H-C-T and PPI network analyses, the key targets were divided into endothelial growth, inflammation and signal transcription-related targets. Further experimental validation showed that HQD targeted estrogen receptor alpha (ESR1) and endothelial growth factor receptors to relieve endothelial dysfunction, thereby improving intestinal barrier function. The expression of inflammatory cytokines and signal transducers was suppressed by HQD treatment and inflammation was inhibited.

CONCLUSIONS

HQD may acts on UC via the regulation of targets and pathways related to improving the intestinal mucosal barrier and ameliorating endothelial dysfunction. Additionally, ERS1 may be a new target to explore the mechanisms of UC.

Inhibiting autophagy enhances sulforaphane-induced apoptosis via targeting NRF2 in esophageal squamous cell carcinoma

Sulforaphane (SFN), a natural anti-tumor compound from cruciferous vegetables, has been reported to induce protective autophagy to cancer cells, which might impair the anti-tumor efficiency of SFN. However, the accurate function and mechanism of SFN inducing autophagy in cancers are still obscure, especially in esophageal squamous cell carcinoma (ESCC), one of malignancies with high incidence in North China. Here, we mainly explored the potential function of autophagy upon SFN treatment in ESCC and molecular mechanism. We demonstrated that SFN could inhibit cell proliferation and induce apoptosis by activating caspase pathway. Moreover, we found activation of NRF2 pathway by SFN was responsible for the induction of autophagy and also a disadvantage element to the anti-tumor effects of SFN on ESCC, indicating that SFN might induce protective autophagy in ESCC. We, therefore, investigated effects of autophagy inhibition on sensitivity of ESCC cells to SFN and found that chloroquine (CQ) could neutralize the activation of SFN on NRF2 and enhance the activation of SFN on caspase pathway, thus improved the anti-tumor efficiency of SFN on ESCC in vitro and in vivo. Our study provides a preclinical rationale for development of SFN and its analogs to the future treatment of ESCC.

Botanical formulation, TADIOS, alleviates lipopolysaccharide (LPS)-Induced acute lung injury in mice via modulation of the Nrf2-HO-1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

TADIOS is an herbal formulation prepared from a mixture of Taraxacum officinale (L.) Weber ex F.H.Wigg, Dioscorea batatas Decaisne and Schizonepeta tenuifolia (Benth.) Briquet. These plants have traditionally been used in Asia to treat a variety of respiratory diseases. A bulk of literature on traditional Korean medicine describe their activities and functions for respiratory problems. Therefore, we hypothesized that the combination of these plants might be effective in alleviating respiratory symptoms.

AIM OF THE STUDY

In this study, we investigated whether TADIOS ameliorates LPS-induced acute lung injury via regulation of the Nrf2-HO-1 signaling pathway.

MATERIALS AND METHODS

The LPS-induced acute lung injury mouse model was used to determine the anti-inflammatory and anti-oxidative stress effects of TADIOS. The amount of marker compounds contained in TADIOS was quantified using high-performance liquid chromatography (HPLC) analysis. The protein level of pro-inflammatory cytokines in culture supernatant was measured by ELISA. Changes in the RNA level of pro-inflammatory cytokines in mice lungs and RAW264.7 cells were measured by quantitative RT-PCR. The relative amounts of reactive oxygen species (ROS) were measured by DCF-DA assay. Western blot analysis was used to evaluate expression of cellular proteins. Effects of TADIOS on antioxidant responsive elements (AREs) were determined by luciferase assay. The severity of acute lung injury was evaluated by Hematoxylin & Eosin (H&E) staining. To test the effects of TADIOS on LPS-induced oxidative stress, myeloperoxidase (MPO) activity and the total antioxidant capacity were measured.

RESULTS

TADIOS was prepared by extraction of a blend of these three plants by ethanol, and quality control was performed through quantification of marker compounds by HPLC and measurement of bioactivities using cell-based bioassays. In the murine macrophage cell line RAW264.7, TADIOS effectively suppressed the production of pro-inflammatory cytokines such as IL-6 and IL-1β, and also ROS induced by LPS. When RAW264.7 cells were transfected with a luciferase reporter plasmid containing nucleotide sequences for AREs, TADIOS treatment increased the level of relative luciferase units in a dose-dependent manner. In the LPS-induced acute lung injury mouse model, orally administered TADIOS alleviated lung damage and neutrophil infiltration induced by LPS. Consistent with the in vitro data, treatment with TADIOS inhibited the LPS-mediated expression of pro-inflammatory cytokines and oxidative stress, and activated the Nrf2-HO-1 axis.

CONCLUSION

Our data suggest the potential for TADIOS to be developed as a safe and effective therapeutics for the treatment of acute respiratory distress syndrome.

Mechanistic interplay of various mediators involved in mediating the neuroprotective effect of daphnetin

Daphnetin is a 7, 8 dihydroxy coumarin isolated from different medicinal plants of the Thymelaeaceae family and exhibits copious pharmacological activities including neuroprotection, anti-cancer, anti-malarial, anti-inflammatory, anti-parasitic and anti-arthritic activity. It has been proved to be an effective neuroprotective agent in several preclinical animal studies and cell line examinations. It is found to interact with different cellular mediators and signaling pathways to confer protection against neurodegeneration. The reactive oxygen species and inflammatory mediators are the major culprits of different neurodegenerative diseases. Oxidative stress activates the pro-apoptotic proteins and inhibits anti-apoptotic proteins, leading to neuronal cell death. Daphnetin restores cellular redox balance by upregulating the antioxidants level (GSH and SOD), anti-apoptotic protein (Bcl-2), as well as by reducing the levels of proinflammatory cytokines, executioner caspase-3, pro-apoptotic-Bax, and oxidative stress markers. Furthermore, activation of Nrf-2/HO-1 signaling and upregulation of HSP-70 governs the protection elicited by daphnetin against oxidative stress-induced neuronal apoptosis. Daphnetin modulated inhibition of JNK-MAPK, JAK-STAT, and TLR-4/NF-κB signaling pathways also contributed to its neuroprotective effect. The positive effects of daphnetin have been also related to its AChE, BChE, and BACE-1 inhibitory potential. The present review has been designed to explore the mechanistic interplay of various mediators in mediating the neuroprotective effects of daphnetin.

The Nrf2 pathway in psychiatric disorders: pathophysiological role and potential targeting

Introduction: All psychiatric disorders exhibit excitotoxicity, mitochondrial dysfunction, inflammation, oxidative stress, and neural damage as their common characteristic. The endogenous nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is implicated in the defense mechanism against oxidative stress and has a significant role in psychiatric disorders.Areas covered: We explore the role of Nrf2 pathway and its modulators in psychiatric disorders. The literature was searched utilizing various databases such as Embase, Medline, Web of Science, Pub-Med, and Google Scholar from 2010 to 2020. The search included research articles, clinical reports, systematic reviews, and meta-analyses.Expert opinion: Environmental factors and genetic predisposition can be a trigger for the development of psychiatric disorders. Nrf2 downregulates certain inflammatory pathways and upregulates various antioxidant enzymes to maintain a balance. However, its intricate balance with NF-Kβ (Nuclear factor kappa light chain enhancer of activated B cells) and its crosstalk with the transcription factor Nrf2 is critical in severe oxidative stress. Several Nrf2 modulators are now in clinical trials and can help reduce oxidative stress and neuroinflammation. There are immense potential opportunities for these modulators to become a novel therapeutic option.

Nobiletin Exhibits Neuroprotective Effects against Mitochondrial Complex I Inhibition via Regulating Apoptotic Signaling

Nobiletin, a polymethoxylated flavonoid found in citrus, has been studied because of its modulatory functions in cellular signaling cascades, and effects to prevent mitochondrial calcium overload and neuronal cell death. Particularly, we previously reported that nobiletin induced changes in the mitochondrial membrane potential through K⁺ channel regulation, suggesting that nobiletin might exert neuroprotective effects via regulating mitochondrial functions associated with the electron transport chain (ETC) system. This study investigated whether nobiletin regulated mitochondrial dysfunction mediated by ETC system downregulation by inhibiting complex I (CI) and complex III (CIII) in pure mitochondria and the cortical neurons of rats. The results showed that nobiletin significantly reduced mitochondrial reactive oxygen species (ROS) production, inhibited apoptotic signaling, enhanced ATP production and then restored neuronal viability under conditions of CI inhibition, but not CIII inhibition. These effects were attributed to the downregulation of translocation of apoptosis-induced factor (AIF), and the upregulation of CI activity and the expression of antioxidant enzymes such as Nrf2 and HO-1. Together with our previous study, these results indicate that the neuroprotective effects of nobiletin under mitochondrial dysfunction may be associated with its function to activate antioxidant signaling cascades. Our findings suggest the possibility that nobiletin has therapeutic potential in treating oxidative neurological and neurodegenerative diseases mediated by mitochondrial dysfunction.

Traditional uses, ten-years research progress on phytochemistry and pharmacology, and clinical studies of the genus Scutellaria

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellaria (Lamiaceae), which includes approximately 360-469 accepted species, is widespread in Europe, North America, East Asia, and South America. Several species have a long history being used as traditional medicines to treat respiratory, peptic, neurological, and hepatic and gall diseases. The phytochemistry and pharmacology of the genus Scutellaria have been developed dramatically in the past ten years, and the traditional uses and clinical studies of the genus have not been systematically summarized. Therefore, it is especially valuable to review the current state of knowledge to provide a basis for further exploration of its medicinal potential.

AIM OF THE REVIEW

The review aims to provide updated information on the ethnopharmacology, the ten-year research progress of phytochemistry and pharmacology, and clinical studies of Scutellaria and to explore the potential medicinal values and further studies of Scutellaria.

MATERIALS AND METHODS

This review is based on published studies and books from the library and electronic sources, including SciFinder, Scopus, PubMed, Web of Science, Baidu Scholar, CNKI, the online ethnobotanical database, and ethnobotanical monographs. This literature is related to ethnopharmacology, the ten-year research progress on the phytochemistry and pharmacology, and clinical studies of Scutellaria.

RESULTS

A total of 50 species, 5 subspecies and 17 varieties of the genus Scutellaria are used as traditional medicine with various biological activities. In the past ten years, 208 chemical constituents have been identified from 16 species and 1 variety of the genus Scutellaria, such as neo-clerodane diterpenoids, sesterterpenoids, terpenoids, flavonoids. Pharmacological research has demonstrated that the extracts and compounds identified from this genus exhibit extensive biological activities, including anticancer, antioxidant, anti-inflammatory, antiviral and antibacterial activities, effects on cardiovascular, cerebrovascular diseases as well as hepatoprotective and neuroprotective effects. The species S. baicalensis, S. barbata, and S. lateriflora and the main compounds baicalein, baicalin and wogonin are involved in clinical trials, which point the way for us to conduct further studies, such as study on the anticancer, antihypertensive, anti-infective, anti-inflammatory, neuroprotective and other effects of Scutellaria.

CONCLUSIONS

The species included in the genus Scutellaria can be used to treat cancer, infection, hepatic disorders, cardiovascular and cerebrovascular diseases, neurodegenerative diseases, and other diseases. Some indications in traditional medicines have been confirmed by modern pharmacological studies, such as anticancer, anti-inflammatory, anti-infective activity, and hepatoprotective and neuroprotective effects. The available literature indicated that most of the bioactivities could be attributed to flavonoids and neo-clerodane diterpenoids. Although there are some uses of Scutellaria in clinical practice, the existing research on this genus is still limited. In order to expand the development of medicinal resources of Scutellaria, the already studied species in this genus are recommended for more comprehensive investigation on their active substances, pharmacological mechanisms, quality control, clinical use and new drug research. Additionally, it is necessary to study species that their chemical composition or pharmacological activity have not yet been investigated, especially those used in folk medicine.

Acidic fibroblast growth factor attenuates type 2 diabetes-induced demyelination via suppressing oxidative stress damage

Prolonged type 2 diabetes mellitus (T2DM) produces a common complication, peripheral neuropathy, which is accompanied by nerve fiber disorder, axon atrophy, and demyelination. Growing evidence has characterized the beneficial effects of acidic fibroblast growth factor (aFGF) and shown that it relieves hyperglycemia, increases insulin sensitivity, and ameliorates neuropathic impairment. However, there is scarce evidence on the role of aFGF on remodeling of aberrant myelin under hyperglycemia condition. Presently, we observed that the expression of aFGF was rapidly decreased in a db/db T2DM mouse model. Administration of exogenous aFGF was sufficient to block acute demyelination and nerve fiber disorganization. Furthermore, this strong anti-demyelinating effect was most likely dominated by an aFGF-mediated increase of Schwann cell (SC) proliferation and migration as well as suppression of its apoptosis. Mechanistically, the beneficial biological effects of aFGF on SC behavior and abnormal myelin morphology were likely due to the inhibition of hyperglycemia-induced oxidative stress activation, which was most likely activated by kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid-derived-like 2 (Nrf2) signaling. Thus, this evidence indicates that aFGF is a promising protective agent for relieving myelin pathology through countering oxidative stress signaling cascades under diabetic conditions.

Ginger (Zingiber officinale roscoe) extract could upregulate the renal expression of NRF2 and TNFα and prevents ethanol-induced toxicity in rat kidney

OBJECTIVE

Ginger has protective effects on the kidney, however the molecular mechanism of this effect has not yet been fully elucidated. Therefore, this work studied molecular mechanisms of ginger effects on ethanol-induced kidney injury.

MATERIALS AND METHODS

Twenty-four male Sprague-Dawley rats were randomly divided into four groups: control, ginger (1 g/kg/day ginger extract by oral gavage), ethanol (4 g/kg/day ethanol by oral gavage) and ginger-ethanol group and treated daily for 28 days. Kidney function, expression of nuclear factor erythroid 2-related factor 2 (NRF2) and tumor necrosis factor (TNF)-α genes and oxidative stress parameters in kidney tissue, were evaluated. Total phenolic content (TPC) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of ginger extract were also evaluated.

RESULTS

Hydroethanolic extract of ginger showed a good level of DPPH scavenging activity and TPC. In the ethanol group, serum level of urea, creatinine and uric acid and the expression of NRF2 and TNF-α significantly increased compared to control group, while co-treatment with ginger in ginger+ethanol group significantly ameliorated them compared to the ethanol group. Ethanol exposure significantly reduced the activity of superoxide dismutase  (SOD), glutathione peroxidase (GPx) and catalase (CAT) compared to the control values ,while the level of malondialdehyde (MDA) significantly increased. Ginger significantly ameliorated the level of MDA and activity of SOD, GPx and CAT in the ginger-ethanol group compared to the ethanol group.

CONCLUSION

The results showed that ginger's protective effects against ethanol renotoxicity were mediated via enhancing the NRF2 and TNF-α expression.

Small Molecule Regulators of Ferroptosis

Ferroptosis is a dedicated mode of cell death involving iron, reactive oxygen species and lipid peroxidation. Involved in processes such as glutathione metabolism, lysosomal iron retention or interference with lipid metabolism, leading either to activation or inhibition of ferroptosis. Given the implications of ferroptosis in diseases such as cancer, aging, Alzheimer and infectious diseases, new molecular mechanisms underlying ferroptosis and small molecules regulators that target those mechanisms have prompted a great deal of interest. Here, we discuss the current scenario of small molecules modulating ferroptosis and critically assess what is known about their mechanisms of action.

Methyl Gallate Attenuates Doxorubicin-Induced Cardiotoxicity in Rats by Suppressing Oxidative Stress

Doxorubicin-induced cardiotoxicity is the leading cause of morbidity and mortality among cancer survivors. The present study was aimed to investigate the cardioprotective potential of methyl gallate; an active polyphenolic nutraceutical, against doxorubicin-induced cardiotoxicity in Wistar rats. Twenty-four female Wistar rats (150-200 g) were divided into four groups (n = 6) which consist of normal control (group I), doxorubicin control (group II), test-A (group III), and test-B (group IV). Group III and group IV animals were prophylactically treated with methyl gallate 150 mg/kg/day and 300 mg/kg/day orally, respectively, for seven days. Doxorubicin (25 mg/kg; single dose) was administered through an intraperitoneal route to group II, III, and IV animals on the seventh day to induce acute cardiotoxicity. On the 8^th day, besides ECG analysis, serum CK, CK-MB, LDH, AST, MDA, and GSH were assayed. Following gross examination of isolated hearts, histopathological evaluation was performed by light microscopy. A significant (p < 0.05) cardiac injury, as well as oxidative stress, was observed in doxorubicin control rats in comparison to normal control rats. Methyl gallate at both the doses significantly (p < 0.05) reduced doxorubicin-induced ECG changes, dyslipidaemia, and elevation of CK, CK-MB, LDH, AST, MDA and increased GSH level. Methyl gallate reversed the doxorubicin-induced histopathological changes in the heart. The present study revealed that methyl gallate exerts cardioprotection against doxorubicin-induced cardiotoxicity in female Wistar rats by suppressing oxidative stress. Our study opens the perspective to clinical studies for consideration of methyl gallate as a potential chemoprotectant nutraceutical in the combination chemotherapy with doxorubicin to limit its cardiotoxicity.

Oxidative stress-mediated hepatotoxicity in rats induced by ethanol extracts of different parts of Chloranthus serratus

CONTEXT

Chloranthus serratus (Thunb.) Roem. et Schult. (Chloranthaceae) is an herb widely used as a folk medicine treating inflammatory diseases, although it is toxic.

OBJECTIVE

To investigate hepatotoxicity and related mechanisms induced by ethanol extracts of different parts of C. serratus in rats.

MATERIALS AND METHODS

Sprague Dawley rats were divided into control (Con), ethanol extract of roots (ER), stems (ES), and leaves (EL) groups, and acute oral toxicity studies were conducted. The rats received doses of 4.14, 3.20, and 1.16 g/kg/d extracts for 14 days, respectively. Liver index, liver function and oxidative stress biomarkers, liver pathology, ultrastructure, TNF-α, ICAM-1, and Nrf2/HO-1 proteins expression levels were determined.

RESULTS

The LD₅₀ of ER, ES, and EL were higher than 10.35, 8.05, and 2.90 g/kg/p.o., respectively. The liver indexes in the extract groups increased significantly. EL dramatically increased TP, GLB, AST, ALT, ALP, TBA, MDA, ICAM-1, and TNF-α levels (p < 0.01), and induced the most obvious pathological and ultrastructural changes. ES and EL obviously decreased the T-SOD, GSH, CAT, and CHOL levels. Nrf2 and HO-1 proteins expression was reduced significantly in ES (0.77 ± 0.06, 2.33 ± 0.20) and EL (0.23 ± 0.04, 2.14 ± 0.16) groups, and reduced slightly in ER (1.08 ± 0.10; 3.39 ± 0.21) group.

DISCUSSION AND CONCLUSION

ES and EL induce stronger hepatotoxicity than ER through oxidative stress and the Nrf2/HO-1 pathway, and the root is a better medicinal part, which provides a basis for clinical research, safe applications, and reasonable development of C. serratus.

Reduction of Oxidative Stress through Activating the Nrf2 mediated HO-1 Antioxidant Efficacy Signaling Pathway by MS15, an Antimicrobial Peptide from Bacillus velezensis

The efficient culture and purification of antimicrobial peptides (AMPs), along with intense antioxidant activity, have drawn the interest to study antioxidant activity mechanism. We report the culture conditions optimization, efficient biosynthesis, and purification of an antioxidant peptide MS15 from Bacillus velezensis obtained from fermented food that would generate heme oxygenase-1 (HO-1) expression and lead to nuclear factor erythroid 2-related factor-2 (Nrf2) nuclear translocation. We explored the ability of kinetics and potency for the bacterial killing to work against various pathogenic bacteria. A bioassay showed the lysis zone of MS15 by tricine SDS-PAGE near at 6 kDa. MALDI-TOF/MS verified molecular weight, and the existence of a molecular mass of 6091 Da was reported by purity. The MIC of MS15 ranged from 2.5-160 μg/mL for many pathogenic bacteria, showing greater potency. In macrophage RAW 264.7 cells, MS15 was exposed to assess its inhibitory effect against the generation of reactive oxygen species (ROS) in oxidative stress. In the sample treated group, the translation, and transcriptional levels of CAT (catalase), GPx (glutathione peroxidase), and SOD (superoxide dismutase) were significantly greater. In short, MS15 has significant antioxidant properties, reducing ROS production in RAW 264.7 cells, and raising the translation and transcriptional rates of antioxidant enzymes with stimulating HO-1 induction facilitated by Nrf2.

miR‑155 modulates high glucose‑induced cardiac fibrosis via the Nrf2/HO‑1 signaling pathway

Cardiac fibrosis is a major pathological manifestation of diabetic cardiomyopathy, which is a leading cause of mortality in patients with diabetes. MicroRNA (miR)‑155 is upregulated in cardiomyocytes in cardiac fibrosis, and the aim of the present study was to investigate if the inhibition of miR‑155 was able to ameliorate cardiac fibrosis by targeting the nuclear factor erythroid‑2‑related factor 2 (Nrf2)/heme oxygenase‑1 (HO‑1) signaling pathway. H9C2 rat cardiomyocytes were cultured with high glucose (HG; 30 mM) to establish an in vitro cardiac fibrosis model that mimicked diabetic conditions; a miR‑155 inhibitor and a miR‑155 mimic were transfected into H9C2 cells. Following HG treatment, H9C2 cells exhibited increased expression levels of miR‑155 and the fibrosis markers collagen I and α‑smooth muscle actin (α‑SMA). In addition, the expression levels of endonuclear Nrf2 and HO‑1 were decreased, but the expression level of cytoplasmic Nrf2 was increased. Moreover, oxidative stress, mitochondrial damage and cell apoptosis were significantly increased, as indicated by elevated reactive oxygen species, malonaldehyde and monomeric JC‑1 expression levels. In addition, superoxide dismutase expression was attenuated and there was an increased expression level of released cytochrome‑c following HG treatment. Furthermore, it was demonstrated that expression levels of Bcl‑2 and uncleaved Poly (ADP‑ribose) polymerase were downregulated, whereas Bax, cleaved caspase‑3 and caspase‑9 were upregulated after HG treatment. However, the miR‑155 inhibitor significantly restored Nrf2 and HO‑1 expression levels, and reduced oxidative stress levels, the extent of mitochondrial damage and the number of cells undergoing apoptosis. Additionally, the miR‑155 inhibitor significantly reversed the expression levels of collagen I and α‑SMA, thus ameliorating fibrosis. Furthermore, the knockdown of Nrf2 reversed the above effects induced by the miR‑155 inhibitor. In conclusion, the miR‑155 inhibitor may ameliorate diabetic cardiac fibrosis by reducing the accumulation of oxidative stress‑related molecules, and preventing mitochondrial damage and cardiomyocyte apoptosis by enhancing the Nrf2/HO‑1 signaling pathway. This mechanism may facilitate the development of novel targets to prevent cardiac fibrosis in patients with diabetes.