Decreased ROS Generation Research Articles

Cardiac Regeneration in Adult Zebrafish: A Review of Signaling and Metabolic Coordination.

This review investigates how post-injury cellular signaling and energy metabolism are two pivotal points in zebrafish's cardiomyocyte cell cycle re-entry and proliferation. It seeks to highlight the probable mechanism of action in proliferative cardiomyocytes compared to mammals and identify gaps in the current understanding of metabolic regulation of cardiac regeneration. Metabolic substrate changes after birth correlate with reduced cardiomyocyte proliferation in mammals. Unlike adult mammalian hearts, zebrafish can regenerate cardiomyocytes by re-entering the cell cycle, characterized by a metabolic switch from oxidative metabolism to increased glycolysis. Zebrafish provide a valuable model for studying metabolic regulation during cell cycle re-entry and cardiac regeneration. Proliferative cardiomyocytes have upregulated Notch, hippo, and Wnt signaling and decreased ROS generation, DNA damage in different zebrafish cardiac regeneration models. Understanding the correlation between metabolic switches during cell cycle re-entry of already differentiated zebrafish cardiomyocytes is being increasingly recognized as a critical factor in heart regeneration. Zebrafish studies provide insights into metabolic adaptations during heart regeneration, emphasizing the importance of a metabolic switch. However, there are mechanistic gaps, and extensive studies are required to aid in formulating therapeutic strategies for cardiac regenerative medicine.

All1750 of Anabaena PCC 7120 encodes a novel NAD+-dependent amine dehydrogenase having broad substrate range.

Native amine dehydrogenases (AmDHs) are rare and typically have narrow substrate specificity and low processivity. Therefore, they are often modified using protein engineering for industrial and pharmaceutical applications. This study presents identification and characterization of a novel native amine dehydrogenase (AmDH) encoding WD40 protein (All1750) from Anabaena PCC 7120. Heterologous expression of all1750 in E. coli enhanced its tolerance to abiotic stressors such as drought, cadmium, and NaCl, as evidenced by increase in gene expression (2-10-fold), spot assay results (3-4-fold) and decreased ROS generation (0.2-1.8-fold). Molecular docking analysis showed that All1750 has broad substrate binding activity, indicating its catalytic potential in amine oxidation. All1750 exhibited the appreciable enzymatic activity with acetophenone (0.8-1.0-fold increase), followed by 4-fluorophenyl acetone and 4-fluoropropiophenone. The Km values for acetophenone and 4-fluorophenyl acetone were 4.2-12.1-fold higher, suggesting a greater affinity of All1750 for these low-cost substrates compared to the expensive 4-fluoropropiophenone. Recombinant All1750 showed optimal enzyme activity at pH8.0 and maintained thermo-stability at 70°C with a half-life of approximately 3h. Our findings provide valuable insights into the industrial application of the All1750 protein. This native AmDH from Anabaena can effectively utilize diverse cost-effective substrates, making it a promising biocatalyst for chiral amine biosynthesis.

Leucine restriction ameliorates Fusobacterium nucleatum-driven malignant progression and radioresistance in nasopharyngeal carcinoma

Radiotherapy resistance is the main cause of treatment failure among patients with nasopharyngeal carcinoma (NPC). Recently, increasing evidence has linked the presence of intratumoral Fusobacterium nucleatum (Fn) with the malignant progression and therapeutic resistance of multiple tumor types, but its influence on NPC has remained largely unknown. We found that Fn is prevalent in the tumor tissue of patients with NPC and is associated with radioresistance. Fn invaded and proliferated inside NPC cells and aggravated tumor progression. Mechanistically, Fn slowed mitochondrial dysfunction by promoting mitochondrial fusion and decreasing ROS generation, preventing radiation-induced oxidative damage. Fn inhibited PANoptosis by the SLC7A5/leucine-mTORC1 axis during irradiation stress, thus promoting radioresistance. Treatment with the mitochondria-targeted antibiotics or dietary restriction of leucine reduced intratumoral Fn load, resensitizing tumors to radiotherapy invivo. These findings demonstrate that Fn has the potential to be a predictive marker for radioresistance and to help guide individualized treatment for patients with NPC.

ZLN005, a PGC-1α Activator, Protects the Liver against Ischemia-Reperfusion Injury and the Progression of Hepatic Metastases.

Exercise can promote sustainable protection against cold and warm liver ischemia-reperfusion injury (IRI) and tumor metastases. We have shown that this protection is by the induction of hepatic mitochondrial biogenesis pathway. In this study, we hypothesize that ZLN005, a PGC-1α activator, can be utilized as an alternative therapeutic strategy. Eight-week-old mice were pretreated with ZLN005 and subjected to liver warm IRI. To establish a liver metastatic model, MC38 cancer cells (1 × 106) were injected into the spleen, followed by splenectomy and liver IRI. ZLN005-pretreated mice showed a significant decrease in IRI-induced tissue injury as measured by serum ALT/AST/LDH levels and tissue necrosis. ZLN005 pretreatment decreased ROS generation and cell apoptosis at the site of injury, with a significant decrease in serum pro-inflammatory cytokines, innate immune cells infiltration, and intrahepatic neutrophil extracellular trap (NET) formation. Moreover, mitochondrial mass was significantly upregulated in hepatocytes and maintained after IRI. This was confirmed in murine and human hepatocytes treated with ZLN005 in vitro under normoxic and hypoxic conditions. Additionally, ZLN005 preconditioning significantly attenuated tumor burden and increased the percentage of intratumoral cytotoxic T cells. Our study highlights the effective protection of ZLN005 pretreatment as a therapeutic alternative in terms of acute liver injury and tumor metastases.

Evaluation of Unsaponifiable Fraction of Avocado Oil on Liver and Kidney Mitochondrial Function in Rats Fed a High-Fat and High-Carbohydrate Diet.

High-fat and high-carbohydrate (HF-HC) diets induce metabolic syndrome via mitochondrial dysfunction and oxidative stress. We have previously shown that this may be prevented by avocado oil, a source of bioactive molecules with antioxidant properties. However, it is unknown if these effects are mediated by the unsaponifiable fraction of avocado oil (UFAO). Thus, we tested if this fraction improves glucose metabolism, bioenergetics and oxidative stress in mitochondria from the kidney and liver of rats fed an HF-HC diet. We found that 12 weeks of an HF-HC diet impaired glucose utilization and increased insulin resistance, which was prevented by UFAO administration. The HF-HC diet decreased respiration, membrane potential and electron transport chain (ETC) function in liver and kidney mitochondria. These mitochondrial dysfunctions were prevented by UFAO intake. Unexpectedly, UFAO increased ROS levels in the mitochondria of control animals and did not decrease them in rats with an HF-HC diet; however, UFAO protects liver and kidney mitochondria from iron-induced oxidative stress. These findings suggest that impairments in glucose metabolism and mitochondrial function by an HF-HC diet may be prevented by UFAO, without decreasing ROS generation but protecting mitochondria from oxidative damage.

Enhanced hypoxanthine utilization for cAMP salvage synthesis efficiently by Arthrobacter sp. CCTCC 2013431 via xanthine oxidase inhibition.

When hypoxanthine was utilized as the activator for the salvage pathway in cAMP synthesis, xanthine oxidase would generate in quantity leading to low hypoxanthine conversion ratios and cell viability. To enhance cAMP salvage synthesis, fermentations with citrate/luteolin and hypoxanthine coupling added were conducted in a 7 L bioreactor and then multiple physiological indicators of fermentation with luteolin addition were assayed. Due to hypoxanthine feeding, cAMP productivity reached 0.066g/(L·h) with 43.5% higher than control, however, cAMP synthesis, cell growth and glucose uptake all ceased at 50h which was shortened by 22h in comparison to control. The addition of citrate resulted in the cessation of fermentation at 61h, on the contrary, owing to luteolin addition, cAMP fermentation performance was enhanced significantly during the whole fermentation period (72h) with higher hypoxanthine conversion ratios and cAMP contents when compared with citrate and only hypoxanthine added batches. Multiple physiological indicators revealed that luteolin inhibited xanthine oxidase activity reducing hypoxanthine decomposition and ROS generation. ATP/AMP, NADH/NAD+ and NADPH/NADP+ were significantly increased especially at the late phase. Moreover, HPRT, PUP expression contents and corresponding gene transcription levels were also elevated. Luteolin could inhibit xanthine oxidase activity and further decrease hypoxanthine decomposition and ROS generation leading to higher hypoxanthine conversion and less cell damage for cAMP salvage synthesis efficiently.

Chlorogenic acid inhibits macrophage PANoptosis induced by cefotaxime-resistant Escherichia coli.

Antibiotics are commonly used in clinical practice to treat bacterial infections. Due to the abuse of antibiotics, the emergence of drug-resistant strains, such as cefotaxime sodium-resistant Escherichia coli (CSR-EC), has aggravated the treatment of diseases caused by bacterial infections in the clinic. Therefore, discovering new drug candidates with unique mechanisms of action is imperative. Chlorogenic acid (CGA) is an active component of Yinhua Pinggan Granule, which has antioxidant and anti-inflammatory effects. We chose the CGA to explore its effects on PANoptosis in cultured macrophages infected with CSR-EC. In this study, we explored the protective impact of CGA on macrophage cell damage generated by CSR-EC infection and the potential molecular mechanistic consequences of post-infection therapy with CGA on the PANoptosis pathway. Our findings demonstrated that during CSR-EC-induced macrophage infection, CGA dramatically increased cell survival. CGA can inhibit pro-inflammatory cytokine expression of IL-1β, IL-18, TNF-α, and IL-6. CGA decreased ROS generation and increased Nrf-2 expression at the gene and protein levels to lessen the cell damage and death brought on by CSR-EC infection. Additionally, we discovered that the proteins Caspase-3, Caspase-7, Caspase-8, Caspase-1, GSDMD, NLRP-3, RIPK-3, and MLKL were all inhibited by CGA. In summary, our research suggests that CGA is a contender for reducing lesions brought on by CSR-EC infections and that it can work in concert with antibiotics to treat CSR-EC infections clinically. However, further research on its mechanism of action is still needed.

Protective Effect of Uridine on Structural and Functional Rearrangements in Heart Mitochondria after a High-Dose Isoprenaline Exposure Modelling Stress-Induced Cardiomyopathy in Rats.

The pyrimidine nucleoside uridine and its phosphorylated derivates have been shown to be involved in the systemic regulation of energy and redox balance and promote the regeneration of many tissues, including the myocardium, although the underlying mechanisms are not fully understood. Moreover, rearrangements in mitochondrial structure and function within cardiomyocytes are the predominant signs of myocardial injury. Accordingly, this study aimed to investigate whether uridine could alleviate acute myocardial injury induced by isoprenaline (ISO) exposure, a rat model of stress-induced cardiomyopathy, and to elucidate the mechanisms of its action related to mitochondrial dysfunction. For this purpose, a biochemical analysis of the relevant serum biomarkers and ECG monitoring were performed in combination with transmission electron microscopy and a comprehensive study of cardiac mitochondrial functions. The administration of ISO (150 mg/kg, twice with an interval of 24 h, s.c.) to rats caused myocardial degenerative changes, a sharp increase in the serum cardiospecific markers troponin I and the AST/ALT ratio, and a decline in the ATP level in the left ventricular myocardium. In parallel, alterations in the organization of sarcomeres with focal disorganization of myofibrils, and ultrastructural and morphological defects in mitochondria, including disturbances in the orientation and packing density of crista membranes, were detected. These malfunctions were improved by pretreatment with uridine (30 mg/kg, twice with an interval of 24 h, i.p.). Uridine also led to the normalization of the QT interval. Moreover, uridine effectively inhibited ISO-induced ROS overproduction and lipid peroxidation in rat heart mitochondria. The administration of uridine partially recovered the protein level of the respiratory chain complex V, along with the rates of ATP synthesis and mitochondrial potassium transport, suggesting the activation of the potassium cycle through the mitoKATP channel. Taken together, these results indicate that uridine ameliorates acute ISO-induced myocardial injury and mitochondrial malfunction, which may be due to the activation of mitochondrial potassium recycling and a mild uncoupling leading to decreased ROS generation and oxidative damage.

Simvastatin’s Mitochondrial Defenses against Angiotensin II-Induced Heart Failure

Background and Aims: Heart failure is one cardiovascular condition that might progress due to mitochondrial dysfunction. In chronic heart failure, 3hydroxy-3-methylglutaryl CoA reductase inhibitors (statins), which prevent the production of ROS, have cardioprotective benefits. However, it is still unknown how statins can protect the mitochondria in heart failure Experimental Strategy: Angiotensin II (1.5 mg/kg/day) or co-administered simvastatin (oral, 10 mg/kg/day) were given to rats for 14 days, after which the treatment was withdrawn. Wheat germ agglutinin staining and echocardiography were used to analyze the structure and function of the heart. Transmission electron microscopy was used to analyze the shape of the mitochondria as well as the numbers of lipid droplets, lysosomes, autophagosomes, and mitophagosomes. After stimulating human cardiomyocytes, flow cytometry was used to assess changes in intracellular ROS and mitochondrial membrane potential (m). and, respectively, JC1 staining. By using immunohistochemistry and western blotting, apoptotic proteins that are associated to autophagy, mitophagy, and mitochondrial regulation were identified. Key outcomes Simvastatin mitigated the disruption of m and dramatically decreased ROS generation. Simvastatin stimulated autophagy and mitophagy, caused lipid droplets to accumulate, and provided energy for maintaining mitochondrial function and impeded apoptosis that was mediated by mitochondria. According to these results, simvastatin-mediated mitochondrial protection prevents heart failure by modifying antioxidant status and enhancing energy sources for autophagy and mitophagy, which prevent mitochondrial damage and cardiomyocyte apoptosis. Final Thoughts and Implications Mitochondria are crucial in controlling the course of heart failure. Simvastatin reduced angiotensin II-induced heart failure through mitochondrial preservation and may offer a new treatment for heart failure prevention.

Wogonin attenuates inflammation and oxidative stress in lipopolysaccharide-induced mastitis by inhibiting Akt/NF-κB pathway and activating the Nrf2/HO-1 signaling.

Mastitis is a disease involved in inflammation of breast which affects human and animals. Wogonin is one bioactive compound from many Chinese herbal medicines, which have multiple properties, including anti-inflammatory activity. However, the roles of wogonin in mastitis progression are largely undefined. Mastitis models were established using LPS-treated mice and mammary epithelial cells (MECs). Infiltration of inflammatory cells was analyzed by hematoxylin-eosin staining and myeloperoxidase (MPO) activity. Inflammatory cytokine (TNF-α and IL-1β) levels were detected via ELISA. The phosphorylation and total of Akt and NF-κB levels and content of Nrf2 and HO-1 were measured via western blot. Cell viability was examined by CCK-8 assay. Oxidative stress was assessed by ROS generation and levels of MDA, GSH, and SOD. Wogonin attenuated LPS-induced infiltration of inflammatory cells, increase of MPO activity and levels of TNF-α and IL-1β, and activation of the Akt/NF-κB pathway in murine mammary gland tissues, and promoted activation of Nrf2/HO-1 signaling. Wogonin did not affect MEC viability, but mitigated LPS-induced inflammation in MECs by reducing TNF-α and IL-1β levels. Wogonin relieved LPS-induced oxidative stress in MECs through decreasing ROS generation and MDA level and increasing GSH and SOD levels. Wogonin repressed LPS-induced activation of the Akt/NF-κB pathway in MECs and increased Nrf2/HO-1 signaling activation. Activated Akt/NF-κB signaling or Nrf2/HO-1 signaling inactivation reversed the suppressive effects of wogonin on LPS-induced inflammation and oxidative stress in MECs. Wogonin mitigates LPS-induced inflammation and oxidative stress of MECs via suppressing activation of the Akt/NF-κB signaling and activating Nrf2/HO-1 pathway, indicating the therapeutic potential of wogonin in mastitis.

Farnesoid X receptor overexpression prevents hepatic steatosis through inhibiting AIM2 inflammasome activation in nonalcoholic fatty liver disease

Oxidative stress-mediated activation of inflammasome has a significant effect on the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Farnesoid X receptor (NR1H4, FXR) has been implicated in biological function and many diseases, including NAFLD. The regulatory effect of FXR on oxidative stress and whether this process is related with the activation of absent melanoma 2 (AIM2) inflammasome in NAFLD remain unclear. In the present research, we confirmed that FXR in the livers of steatosis patients is significantly reduced compared with normal liver tissue by using the Gene Expression Omnibus (GEO) database and a palmitic acid (PA) - mediated steatosis model in AML-12 cells. Under the premise of ensuring the same food intake as the control group, overexpression of FXR in mice attenuated HFD-mediated weight gain and liver steatosis, facilitated lipid metabolism, improved fatty acid β-oxidation, lipolysis, and reduced fatty acid synthesis and intake, which also inhibited the activation of AIM2 inflammasome. Overexpression of FXR alleviated PA-induced triglyceride (TG) accumulation, imbalance of lipid homeostasis, and the activation of AIM2 inflammasome in hepatic steatosis cells, while FXR knockdown appeared the opposite effects. FXR overexpression suppressed PA- and HFD-induced oxidative stress, but FXR siRNA demonstrated the opposite influence. The decreased ROS generation may be the reason why FXR weakens AIM2 activation when a fatty acid overload occurs. In conclusion, our results confirm that other than regulating lipid homeostasis and blocking NLRP3 inflammasome activation, FXR improves hepatic steatosis by a novel mechanism that inhibits oxidative stress and AIM2 inflammasome activation.

The role of EndophilinA1 in chronic unpredicted mild stress-induced depression model mice

BackgroundDepression is a common mental disease, accompanied by anxiety and persistent depression. Endophilin A1 (EPA1) is a brain-specific protein enriched in synaptic terminals that is primarily expressed in the central nervous system. It has been reported that EPA1 is involved in neurotransmitter release, which indicates that the protein may be involved in depression. However, it is unclear whether EPA1 is implicated in the development of depression. MethodsThe mice depression model was established by chronic unpredicted mild stress (CUMS). Depression-like behaviors were detected by sucrose preference test (SPT), forced swim test (FST), tail-suspension test (TST) and open-field test (OFT). Neuronal histopathology was applied by hematoxylin and eosin stain (H&E), and Nissl stain. EPA1, NLRP1 inflammatory complexes, NADPH oxidase2 (NOX2), synaptic-related protein expression of the mice were tested by western blot. Immunofluorescence was applied to detect the expression of EPA1 and ROS in mice hippocampus. EPA1 knockdown was performed by an adeno-associated virus (AAV) vector containing EPA1-shRNA-EGFP infusion. ResultCUMS exposure induced depressive-like behaviors and increased the expression of EPA1 in the hippocampus. Knockdown hippocampal EPA1 ameliorated CUMS-induced depressive-like behaviors, decreased calcium (Ca2+) overload, decreased ROS generation and NOX2 expression, inhibited NLRP1 inflammasome-driven neuroinflammation, and restored the levels of BDNF, PSD95, GAP-43, SYN, and MAP-2 in the hippocampus. ConclusionEPA1 contributes to CUMS induced depressive-like behaviors and the mechanism may be related to NLRP1 inflammasome-driven inflammatory response, regulating calcium ion homeostasis and ROS generation, and alleviating synaptic function damage. This indicated that EPA1 may participate in the occurrence and development of depression.

ROLE OF METALLOPROTEINASES AND ROS GENERATION IN THE AORTA OF ELASTASE-2 KNOCKOUT MICE IN ABDOMINAL AORTIC ANEURYSM MODEL

Objective: Elastase-2 (ELA-2) enzyme generates angiotensin-II (AngII) in arteries and is implicated in abnormal vascular remodeling in animal models. Our group demonstrated previously that ELA-2 knockout (ELA-2KO) mice were less susceptible to developing an aorta dilation in response to AngII infusion. This study hypothesizes that metalloproteinases and ROS generation in ELA-2KO mice mediate less susceptibility to aorta dilation and abdominal aortic aneurysm (AAA). Design and method: Male wild type (C57bl/6, WT) and ELA-2KO (CELA-2aTm1Bdr) mice were treated with either saline or AngII (2.28g/g/min) for twenty-eight days by subcutaneously mini-pumps infusion. Mice were divided into four groups: WT treated with saline (WT+SAL, n = 5), ELA-2KO treated with saline (ELA-2KO+SAL, n = 5), WT treated with AngII (WT+AngII,n = 5), and ELA-2KO treated with AngII (ELA-2KO+AngII, n = 5). The vascular ultrasound (US) was done before treatment and once a week during 28 days of treatment. The MMP- 2 and MMP-9 analyzes were done by zymography, ROS generation by DHE analyses, and alfa-actin expression by immunofluorescence in all aorta mice groups. ANOVA and Kruskal Wallis tests were used to compare the average between groups. This study is approved by CEUA (n.131/2019). Results: AngII treatment was associated with increased MMPs expression in the WT group aorta (WT+AngII vs. WT+SAL p<0.05). The aorta ELA-2KO group showed no difference in MMPs in response to AngII infusion compared to ELA-2KO+SAL group (p = 0.81). The ROS generation had upregulated in aorta ELA-2KO+Ang II mice compared to ELA-2KO+SAL (p<0.001) and aorta WT+AngII compared with WT+SAL (p<0.0001). AngII treatment was associated with decreased ROS generation in the aorta ELA-2KO+AngII group compared with WT+AngII (p = 0.0051). The alfa-actin expression was similar in all groups. Our data demonstrate that AngII treatment did not increase the expression of MMPs in aorta ELA-2KO but was associated with an upregulation for ROS generation. Conclusions: Taken together, this suggests that ELA-2KO mice's resistance to developing an aorta dilation/AAA is related to MMPs and ROX generation. Our results also highlight the importance of the local/tissue response in the pathophysiology of AAA.

Effect of mitoTEMPO on Redox Reactions in Different Body Compartments upon Endotoxemia in Rats.

Mitochondrial ROS (mitoROS) control many reactions in cells. Biological effects of mitoROS in vivo can be investigated by modulation via mitochondria-targeted antioxidants (mtAOX, mitoTEMPO). The aim of this study was to determine how mitoROS influence redox reactions in different body compartments in a rat model of endotoxemia. We induced inflammatory response by lipopolysaccharide (LPS) injection and analyzed effects of mitoTEMPO in blood, abdominal cavity, bronchoalveolar space, and liver tissue. MitoTEMPO decreased the liver damage marker aspartate aminotransferase; however, it neither influenced the release of cytokines (e.g., tumor necrosis factor, IL-4) nor decreased ROS generation by immune cells in the compartments examined. In contrast, ex vivo mitoTEMPO treatment substantially reduced ROS generation. Examination of liver tissue revealed several redox paramagnetic centers sensitive to in vivo LPS and mitoTEMPO treatment and high levels of nitric oxide (NO) in response to LPS. NO levels in blood were lower than in liver, and were decreased by in vivo mitoTEMPO treatment. Our data suggest that (i) inflammatory mediators are not likely to directly contribute to ROS-mediated liver damage and (ii) mitoTEMPO is more likely to affect the redox status of liver cells reflected in a redox change of paramagnetic molecules. Further studies are necessary to understand these mechanisms.

Phytochemical analysis and nephroprotective potential of Ajwa date in doxorubicin-induced nephrotoxicity rats: Biochemical and molecular docking approaches.

The purpose of this study is to evaluate the likely defensive impact of Ajwa date aqueous extract (AJDAE) in alleviating the nephrotoxicity generated by doxorubicin (DOX) injection in rats. Sixty male Wister albino rats were randomly and equally separated into six groups (n= 10), and they were treated as follows: untreated control group, extract groups administered with 0.75 and 1.5mg kg bw of AJDAE, toxicant control group administered with DOX, and prophylactic groups were treated with 0.75 and 1.5 mg/kg of AJDAE and 15 mg/kg DOX. Biochemical parameters, antioxidant enzymes, renal functions, DNA integrity, and histopathology were studied to evaluate the nephroprotective activity of AJDAE. Furthermore, bioactive compounds were utilized for in silico molecular docking. AJDAE treatment resulted in significant improvements in the amended renal biomarkers (urea, creatinine, calcium, phosphorous, and uric acid), antioxidative markers, and MDA. Noticeable histopathological improvements supported this result. Results of in silico studies revealed that d-Mannitol, 6TMS derivative, palmitic acid, and TMS derivative had a higher docking score with human soluble epoxide hydrolase (-10.9kcal/mol) and NF-κB-DNA (-7kcal/mol). The present findings indicated that AJDAE could decrease ROS generation and lipid peroxidation (LPO) and repair the DOX injection-related DNA damage.

Evaluation of toxicological effects of bisphenol S with an in vitro human bone marrow mesenchymal stem cell: Implications for bone health

As the use of bisphenol A (BPA) has been restricted in consumer products, bisphenol S (BPS) is one major alternative to BPA for various materials, leading to growing concerns about its health risks in human beings. However, little is known about the toxic effects of BPS on bone health. We employed human bone marrow mesenchymal stem cells (hBMSCs) for the in vitro assessment of BPS on cell proliferation, differentiation, and self-renewal. Our study revealed that BPS at concentrations of 10−10-10−7 M increased cell viability but induced the morphological changes of hBMSCs. Moreover, BPS decreased ROS generation and increased Nrf2 expression. Furthermore, BPS not only activated ERα/β expression but also increased β-catenin expression and induced the replicative senescence of hBMSCs. Furthermore, we found that the upregulation of β-catenin induced by BPS was mediated, in part, by ER signaling. Overall, our results suggested BPS exposure caused the homeostatic imbalance of hBMSCs.

Galangin Exhibits Neuroprotective Effects in 6-OHDA-Induced Models of Parkinson's Disease via the Nrf2/Keap1 Pathway.

Parkinson’s disease (PD) is the second most common neurodegenerative disease, and there is still no cure for it. PD is characterized by the degeneration of dopaminergic neurons, and oxidative stress has been considered an important pathological mechanism. Therefore, the discovery of antioxidants to alleviate the oxidative damage of dopaminergic neurons is a promising therapeutic strategy for PD. First, a network pharmacology approach was used, and nine common core targets of galangin and PD were screened, mainly involving cell aging, apoptosis, and cellular responses to hydrogen peroxide and hypoxia. In addition, the Gene Ontology (GO) function and pathway enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) identified apoptosis, PI3K/Akt, and HIF-1 signaling pathways. Furthermore, the molecular docking results revealed a strong affinity between galangin and the NFE2L2/Nrf2 protein. To validate the above predictions, we employed 6-hydroxydopamine (6-OHDA) to induce neuronal death in HT22 cells and Caenorhabditis elegans (C. elegans). MTT, cell morphology observation, and Hoechst 33342-PI staining results showed that galangin significantly increased the viability of 6-OHDA-treated HT22 cells. In addition, galangin inhibited 6-OHDA-induced ROS generation and apoptosis in HT22 cells. Mechanistic studies demonstrated that galangin activates the Nrf2/Keap1 signaling pathway, as evidenced by the decreased protein expression of Keap1 and increased protein expression of Nrf2 and HO-1. In the 6-OHDA-induced PD model of C. elegans, galangin indeed inhibited the degeneration of dopaminergic neurons, improved behavioral ability, and decreased ROS generation. In conclusion, the current study is the first to show that galangin has the capacity to inhibit neuronal degeneration via the Nrf2/Keap1 pathway, suggesting that galangin is a possible PD treatment.

Catalpol Ameliorates Neurotoxicity in N2a/APP695swe Cells and APP/PS1 Transgenic Mice

Alzheimer's disease (AD) causes progressive decline of memory and cognitive deficits. Because of its complicated pathogenesis, the prevention and therapy of AD remain an enormous challenge. It has been reported that catalpol possessed neuroprotective effects against AD. However, the involved mechanism still needs to be intensively studied. Therefore, the effects of catalpol on N2a/APP695swe cells and APP/PS1 mice were identified in the current study. Catalpol could improve cytotoxicity according to CCK-8 assay and ameliorate cellular morphological changes in N2a/APP695swe cells. Neuronal structural damage in the hippocampal CA1 region of APP/PS1 AD mice was improved according to HE staining and immunohistochemistry of NeuN. Meanwhile, catalpol administration ameliorated cognitive deficits confirmed by behaviorperformance of APP/PS1 mice. Hoechst 33,342 staining and Annexin V-FITC/PI double staining demonstrated that catalpol could reduce apoptosis in N2a/APP695swe cells. Likewise, TUNEL staining also manifested that catalpol significantly reduced apoptosis in hippocampal CA1 region of APP/PS1 mice. Catalpol administration also could improve mitochondrial functions indicated by the ameliorative mitochondrial morphology, the decreased ROS generation, and the increased MMP in N2a/APP695swe cells. Subsequently, catalpol restrained oligomerization of Aβ1-42, verified by a reduced ThT fluorescence dose- and time-dependently. Additionally, both Aβ1-40 and Aβ1-42 aggregation were decreased in N2a/APP695swe cells and APP/PS1 mice administrated with catalpol confirmed by ELISA and western blot. Western blot also showed that catalpol facilitated the phosphorylation of AKT and GSK3β, and impeded the expression of BACE1 both in vivo and in vitro. Finally, a slight alteration in lactylation, 2-hydroxyisobutyrylation, and phosphorylation were found in N2a/APP695swe cells treated with catalpol. Together, these findings manifested that catalpol served a neuroprotective effect in AD and might be a novel and expecting prophylactic or curative candidate for AD or neurodegenerative diseases therapy.

Biological Evaluation of Avocado Residues as a Potential Source of Bioactive Compounds.

Avocado seed and peel are the main by-products from avocado industrialisation, and account for nearly 30% of fruit weight. Although they are usually discarded, their high phenolic content has been deeply associated with several nutritional and functional benefits. Thus, for a comprehensive analytical evaluation of both semi-industrial extracts, various steps have been developed: tentative characterisation and quantification of the phenolic composition using HPLC-ESI-qTOF-MS, determination of TPC and antioxidant activity by Folin–Ciocalteu, FRAP, TEAC and ORAC methods, evaluation of scavenging capacity against different ROS and measurement of the enzymatic inhibitory potential against potentially harmful enzymes. Finally, their bioactive potential was tested in a human platelet model where antiaggregatory activity was measured. Hence, 48 different compounds were identified, where flavonoids and procyanidins were the most representative groups. The higher TPC was found in avocado peel extract (190 ± 3 mg/g), which showed more antioxidant power and more capacity to decrease ROS generation than seed extract (60 ± 2 mg/g). In addition, both extracts showed enzymatic inhibition, especially against hyaluronidase, xanthine oxidase and acetylcholinesterase. Lastly, avocado peel was proven to inhibit platelet aggregation with significant results at 1, 0.75 and 0.5 mg/mL, where the extract showed reducing effects on agonists’ expression such as p-selectin or GPIIb/IIIa complex. These results demonstrate that both semi-industrial extracts—above all, avocado peel—have an interesting potential to be exploited as a natural by-product with antioxidant properties with multiple applications for the prevention of different pathologies.

Synthesis and biological evaluation of scutellarein derivatives as neuroprotective agents via activating Nrf2/HO-1 pathway

Oxidative stress has been considered as the main factor of neurodegenerative diseases. Activation of the Nrf2/HO-1 pathway, as one of the most crucial endogenous protection systems, was regarded as an effective strategy to against oxidative injury. Here, a series of phosphate esters or phosphonates of scutellarein derivatives were designed, synthesized and evaluated on SH-SY5Y cell lines to examine neuroprotective effects against H2O2 induced damage. Among them, compound 16d exhibited more potent cytoprotective effect than the lead compound scutellarin. Preliminary mechanism studies showed that compound 16d could prevent H2O2 induced neuronal apoptosis, significantly decrease ROS generation, elevate SOD and reduce MDA levels in a dose-dependent manner in SH-SY5Y cell lines. Furthermore, western blot assay disclosed that compound 16d could activate Nrf2, and increase the expression of its downstream genes HO-1 in a concentration-dependent manner, thus displaying potent neuroprotective activity. Overall, these findings demonstrated that compound 16d, as a promising neuroprotective agent, deserved further development.