Diphenyl diselenide regulates Nrf2/Keap-1 signaling pathway and counteracts hepatic oxidative stress induced by bisphenol A in male mice

Oligosaccharides from black ginseng innovatively prepared by low-temperature steam-heating process ameliorate cognitive impairment in Alzheimer's disease mice via the Keap-1/Nrf2 pathway

BACKGROUND

Our objective in this study was to evaluate the effectiveness of oligosaccharides extracted from black ginseng (OSBG), innovatively prepared by a low-temperature steam-heating process, in the improvement of learning and memory impairment in mice, as well as the mechanism(s).

RESULTS

Eight carbohydrates involving isomaltose and maltotetraose were detected in black gensing; monosaccharide residues including mannose and rhamnose were also discovered. OSBG-treated mice showed significant amelioration in recognition and spatial memory deficits compared to the scopolamine group. OSBG could decrease acetylcholinesterase activity in a tissue-dependent fashion but not in a dose-dependent manner. Furthermore, in contrast, OSBG administration resulted in significant upregulation superoxide dismutase, glutathione, glutathione peroxidase (GPx), and Kelch-like ECH-associated protein 1, downregulation of malondialdehyde and nuclear factor erythroid 2-related factor 2 in the tissues. Finally, at the genus level, we observed that the OSBG interventions increased the relative abundance of probiotics (e.g., Barnesiella, Staphylococcus, Clostridium_XlVb) and decreased pernicious bacteria such as Eisenbergiella and Intestinimonas, compared to the Alzheimer's disease mouse model group. Herein, our results demonstrate that OSBG restores the composition of the scopolamine-induced intestinal microbiota in mice, providing homeostasis of gut microbiota and providing evidence for microbiota-regulated therapeutic potential.

CONCLUSION

Our results showed for the first time a clear role for OSBG in improving scopolamine-induced memory impairment by inhibiting cholinergic dysfunction in a tissue-dependent manner. Additionally, OSBG administration relieved oxidative stress by activating the Keap-1/Nrf2 pathway and modulating the gut microbiota. Collectively, OSBG may be a promising target for neuroprotective antioxidants for improving memory and cognition in Alzheimer's disease patients. © 2024 Society of Chemical Industry.

Nrf2-mediated protective effect of alpha-lipoic acid on synaptic oxidative damage and inhibition of PKC/ERK/CREB pathway in bisphenol A-exposed HT-22 cells

The harmful effects of bisphenol A (BPA) on learning and memory may involve hippocampal oxidative damage; however, the underlying mechanism remains unclear. Antioxidants that antagonize BPA-induced neuronal oxidative damage lack research. This study aimed to develop an in vitro model using the HT-22 mouse hippocampal neuronal cell line to investigate the neurotoxic mechanism of BPA and the protective effect of alpha-lipoic acid (ALA) on nuclear factor erythroid 2-related factor 2 (Nrf2) inhibition. The results showed that ALA reduced BPA-induced reactive oxygen species and neuronal nitric oxide synthase (nNOS) levels; however, inhibiting Nrf2 weakened the protective effects of ALA. BPA reduced mitochondrial complex I/III activity and ATP levels, but ALA ameliorated this damage. ALA improved the BPA-induced downregulation of the kelch-like ECH-associated protein 1 (keap1)/Nrf2 system, synaptic-related proteins, and the protein kinase C (PKC)/extracellular signal-regulated kinase (ERK)/cAMP response element binding protein (CREB) pathway; however, the protective effects of ALA were weakened when Nrf2 was inhibited. Our results suggest that BPA causes oxidative damage to HT-22 cells by damaging mitochondrial function, nNOS, and the keap1/Nrf2 system, thereby impairing synaptic-related proteins and the PKC/ERK/CREB pathway. ALA counters BPA-induced damage via Nrf2, which may be a significant target for the protective action of ALA.

ETS1 Ameliorates Hyperoxia-Induced Bronchopulmonary Dysplasia in Mice by Activating Nrf2/HO-1 Mediated Ferroptosis

PURPOSE

Bronchopulmonary dysplasia (BPD) is associated with hyperoxia-induced oxidative stress-associated ferroptosis. This study examined the effect of E26 oncogene homolog 1 (ETS1) on oxidative stress-associated ferroptosis in BPD.

METHODS

Hyperoxia-induced A549 cells and neonatal mice were used to establish BPD models. The effects of ETS1 on hyperoxia-induced ferroptosis-like changes in A549 cells were investigated by overexpression of ETS1 plasmid transfection and erastin treatment. Glucose consumption, lactate production, and NADPH levels were assessed by the glucose, lactate, and NADP+/NADPH assay kits, respectively. The potential regulatory relationship between ETS1 and Nrf2/HO-1 was examined by treating hyperoxia-induced A549 cells with the Nrf2 inhibitor ML385. ETS1 effect on the Nrf2 promoter was explored by dual-luciferase reporter and chromatin immunoprecipitation assay. The effect of ETS1 on the symptoms of BPD mice was examined by injecting an adenovirus overexpressing ETS1.

RESULTS

ETS1 overexpression increased hyperoxia-induced cell viability, glucose consumption, lactate production, and NADPH levels and reduced inflammation and apoptosis in A549 cells. In animal experiments, ETS1 overexpression prevented weight loss, airway enlargement, and reductions in radial alveolar counts in BPD mice, while reducing the mean linear intercept, mean alveolar diameter and inflammation. ETS1 overexpression suppressed PTGS2 and CHAC1 expression, reduced ROS, MDA and ferrous iron (Fe2+) production and increased GSH levels in hyperoxia-induced A549 cells and BPD mice. In addition, ETS1 can bind to the Nrf2 promoter region and thus promote Nrf2 transcription. ETS1 overexpression increased the mRNA and protein levels of Nrf2, HO-1, xCT, and GPX4 in hyperoxia-induced A549 cells and BPD mice. In hyperoxia-induced A549 cells, erastin and ML385 treatment abolished the effect of ETS1 overexpression.

CONCLUSION

ETS1 is important in oxidative stress-related ferroptosis in a hyperoxia-induced BPD model, and the effect is partially mediated by the Nrf2/HO-1 axis.

Neurodegenerative Proteinopathies Induced by Environmental Pollutants: Heat Shock Proteins and Proteasome as Promising Therapeutic Tools

Environmental pollutants' (EPs) amount and diversity have increased in recent years due to anthropogenic activity. Several neurodegenerative diseases (NDs) are theorized to be related to EPs, as their incidence has increased in a similar way to human EPs exposure and they reproduce the main ND hallmarks. EPs induce several neurotoxic effects, including accumulation and gradual deposition of misfolded toxic proteins, producing neuronal malfunction and cell death. Cells possess different mechanisms to eliminate these toxic proteins, including heat shock proteins (HSPs) and the proteasome system. The accumulation and deleterious effects of toxic proteins are induced through HSPs and disruption of proteasome proteins' homeostatic function by exposure to EPs. A therapeutic approach has been proposed to reduce accumulation of toxic proteins through treatment with recombinant HSPs/proteasome or the use of compounds that increase their expression or activity. Our aim is to review the current literature on NDs related to EP exposure and their relationship with the disruption of the proteasome system and HSPs, as well as to discuss the toxic effects of dysfunction of HSPs and proteasome and the contradictory effects described in the literature. Lastly, we cover the therapeutic use of developed drugs and recombinant proteasome/HSPs to eliminate toxic proteins and prevent/treat EP-induced neurodegeneration.

Moderate exercise-induced dynamics on key sepsis-associated signaling pathways in the liver

BACKGROUND

There is a clear relationship between quantitative measures of fitness (e.g., VO₂ max) and outcomes after surgical procedures. Whether or not fitness is a modifiable risk factor and what underlying biological processes drive these changes are not known. The purpose of this study was to evaluate the moderate exercise training effect on sepsis outcomes (survival) as well as the hepatic biological response. We chose to study the liver because it plays a central role in the regulation of immune defense during systemic infection and receives blood flow directly from the origin of infection (gut) in the cecal ligation and puncture (CLP) model.

METHODS

We randomized 50 male (♂) and female (♀) Sprague-Dawley rats (10 weeks, 340 g) to 3 weeks of treadmill exercise training, performed CLP to induce polymicrobial "sepsis," and monitored survival for five days (Part I). In parallel (Part II), we randomized 60 rats to control/sedentary (G1), exercise (G2), exercise + sham surgery (G3), CLP/sepsis (G4), exercise + CLP [12 h (G5) and 24 h (G6)], euthanized at 12 or 24 h, and explored molecular pathways related to exercise and sepsis survival in hepatic tissue and serum.

RESULTS

Three weeks of exercise training significantly increased rat survival following CLP (polymicrobial sepsis). CLP increased inflammatory markers (e.g., TNF-a, IL-6), which were attenuated by exercise. Sepsis suppressed the SOD and Nrf2 expression, and exercise before sepsis restored SOD and Nrf2 levels near the baseline. CLP led to increased HIF1a expression and oxidative and nitrosative stress, the latter of which were attenuated by exercise. Haptoglobin expression levels were increased in CLP animals, which was significantly amplified in exercise + CLP (24 h) rats.

CONCLUSIONS

Moderate exercise training (3 weeks) increased the survival in rats exposed to CLP, which was associated with less inflammation, less oxidative and nitrosative stress, and activation of antioxidant defense pathways.

Zinc Deficiency Exacerbates Bisphenol A-Induced Hepatic and Renal Damage: Delineation of Molecular Mechanisms

Zinc (Zn) plays an important role in the maintenance of redox status in the biological system. Zn deficiency has been found to be associated with negative effects on the functioning of many organ systems, including hepatic and renal systems. Bisphenol A (BPA) can alter Zn homeostasis and perturb the physiological system by provoking oxidative stress, which can lead to damage of different organs such as reproductive, immune, neuroendocrine, hepatic and renal systems. The present study aims to investigate the toxicity of BPA in Zn deficient condition in the liver and kidney of rat and to correlate its synergistic actions. Zn deficiency was induced by feeding Zn-deficient diet (ZDD), and BPA was administered orally (100 mg/kg/d). Male Sprague-Dawley rats were divided into four groups: NPD + Vehicle (normal feed and water), NPD + BPA (100 mg/kg/d), ZDD + Vehicle (fed with Zn-deficient diet only) and ZDD + BPA (Zn-deficient diet + BPA; 100 mg/kg/d) for 8 weeks. Biochemical, histopathological, TUNEL assay and protein expression profiles were determined to decipher the oxidative damage induced by ZDD and the toxicant BPA. Expression profile of nuclear factor erythroid 2-related factor 2, proliferating cell nuclear antigen, kelch-like ECH-associated protein 1, superoxide dismutase-1, metallothionein and apoptosis incidence showed that ZDD and BPA have a synergistic exacerbation effect on the liver and kidney of rat.

(m-CF3-PhSe)2 counteracts metabolic disturbances and hypothalamic inflammation in a lifestyle rodent model

An unhealthy lifestyle is associated with metabolic disorders and neuroinflammation. In this study, the efficacy of m-trifluoromethyl-diphenyl diselenide [(m-CF₃-PhSe)₂] against lifestyle model-related metabolic disturbances and hypothalamic inflammation in young mice was investigated. From postnatal day 25 (PND25) to 66, male Swiss mice were subjected to a lifestyle model, an energy-dense diet (20:20% lard: corn syrup) and sporadic ethanol (3x/week). Ethanol was administrated intragastrically (i.g., 2g/kg) to mice from PND45 to 60. From PND60 to 66, mice received (m-CF₃-PhSe)₂ (5mg/kg/day; i.g). (m-CF₃-PhSe)₂ reduced relative abdominal adipose tissue weight, hyperglycemia, and dyslipidemia in mice exposed to the lifestyle-induced model. (m-CF₃-PhSe)₂ normalized hepatic cholesterol and triglyceride levels, and the activity of G-6-Pase increased in lifestyle-exposed mice. (m-CF₃-PhSe)₂ was effective in modulating hepatic glycogen levels, citrate synthase and hexokinase activities, protein levels of GLUT-2, p-IRS/IRS, p-AKT/AKT, redox homeostasis, and inflammatory profile of mice exposed to a lifestyle model. (m-CF₃-PhSe)₂ counteracted hypothalamic inflammation and the ghrelin receptor levels in mice exposed to the lifestyle model. (m-CF₃-PhSe)₂ reversed the decreased levels of GLUT-3, p-IRS/IRS, and the leptin receptor in the hypothalamus of lifestyle-exposed mice. In conclusion, (m-CF₃-PhSe)₂ counteracted metabolic disturbances and hypothalamic inflammation in young mice exposed to a lifestyle model.

Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs

In 2015, EFSA established a temporary tolerable daily intake (t-TDI) for BPA of 4 μg/kg body weight (bw) per day. In 2016, the European Commission mandated EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation. The CEP Panel concluded that it is Unlikely to Very Unlikely that BPA presents a genotoxic hazard through a direct mechanism. Taking into consideration the evidence from animal data and support from human observational studies, the immune system was identified as most sensitive to BPA exposure. An effect on Th17 cells in mice was identified as the critical effect; these cells are pivotal in cellular immune mechanisms and involved in the development of inflammatory conditions, including autoimmunity and lung inflammation. A reference point (RP) of 8.2 ng/kg bw per day, expressed as human equivalent dose, was identified for the critical effect. Uncertainty analysis assessed a probability of 57-73% that the lowest estimated Benchmark Dose (BMD) for other health effects was below the RP based on Th17 cells. In view of this, the CEP Panel judged that an additional uncertainty factor (UF) of 2 was needed for establishing the TDI. Applying an overall UF of 50 to the RP, a TDI of 0.2 ng BPA/kg bw per day was established. Comparison of this TDI with the dietary exposure estimates from the 2015 EFSA opinion showed that both the mean and the 95th percentile dietary exposures in all age groups exceeded the TDI by two to three orders of magnitude. Even considering the uncertainty in the exposure assessment, the exceedance being so large, the CEP Panel concluded that there is a health concern from dietary BPA exposure.

Protective effects of cyanidin-3-O-glucoside on BPA-induced neurodevelopmental toxicity in zebrafish embryo model

Bisphenol A (BPA) is ubiquitous in the environment and poses a threat to wildlife and human health. It has been reported that BPA may cause the neurotoxicity during gestational and neonatal periods. Cyanidin-3-O-glucoside (C3G) is one of the most abundant anthocyanins that has shown multiple bio-functions. In this study, the protective effects and possible mechanism of C3G against BPA-induced neurodevelopment toxicity in zebrafish embryos/larvae were studied. The results showed that co-exposure of C3G (25 μg/mL) significantly attenuated BPA-induced deficit in locomotor behavior and restored the BPA-induced aberrant changes in brain morphology of zebrafish larvae. Further studies showed that the defects of central nervous development and the downregulated neurogenesis relative genes induced by BPA were significantly counteracted by co-exposure with 5 μg/mL of C3G. In addition, C3G (25 μg/mL) mitigated the decline of glutathione (GSH) content and enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT), attenuated oxidative stress and cell apoptosis induced by BPA in zebrafish. The enhancements of the expression of genes involved in the Nrf2-ARE pathway (Nrf2, HO-1, NQO1, GCLC, and GCLM) were also observed by co-exposure of C3G. The results indicate that C3G exerts protective effects on BPA-induced neurodevelopmental toxicity through improving transcription of neurogenesis related genes, enhancing antioxidative defense system and reducing cell apoptosis by regulation of apoptotic genes in zebrafish larvae. The results suggest that anthocyanins may play important role against the exogenous toxicity for vertebrates.

Effects of antioxidants on diabetic kidney diseases: mechanistic interpretations and clinical assessment

Diabetic kidney disease (DKD) is more prevalent with an increase in diabetes mellitus. Oxidative stress is a major factor in the occurrence and progression of DKD. Defending against oxidative stress and restoring antioxidant defense might be key to preventing and treating DKD. The purpose of this article is to provide an explanation of how oxidative stress affects DKD, conduct a systematic review and meta-analysis on DKD, and examine the effect of antioxidants on the disease. An analysis of 19 randomized controlled trials showed that the use of antioxidants could reduce UAE (albumin excretion rate) in patients with DKD (SMD: - 0.31; 95% CI [- 0.47, - 0.14], I² = 0%), UACR (urine albumin/creatinine ratio) (SMD: - 0.60; 95% CI [- 1.15, - 0.06], I² = 89%), glycosylated hemoglobin (hbA1c) (MD: - 0.61; 95% CI [- 1.00, - 0.21], I² = 93%) and MDA (malonaldehyde) (SMD:-1.05; 95% CI [- 1.87, - 0.23], I² = 94%), suggesting that antioxidants seemed to have therapeutic effects in patients with DKD, especially in reducing proteinuria and hbA1c. The purpose of this study is to provide new targets and ideas for drug research and clinical treatment of DKD.

Locust Bean Gum Nano-Based Hydrogel for Vaginal Delivery of Diphenyl Diselenide in the Treatment of Trichomoniasis: Formulation Characterization and In Vitro Biological Evaluation

Trichomoniasis is the most common nonviral sexually transmitted infection in the world, but its available therapies present low efficacy and high toxicity. Diphenyl diselenide (PhSe₂) is a pharmacologically active organic selenium compound; however, its clinical use is hindered by its lipophilicity and toxicity. Nanocarriers are an interesting approach to overcome the limitations associated with this compound. This study designed and evaluated a vaginal hydrogel containing PhSe₂-loaded Eudragit^® RS100 and coconut oil nanocapsules for the treatment of trichomoniasis. Nanocapsules presented particle sizes in the nanometric range, positive zeta potential, a compound content close to the theoretical value, and high encapsulation efficiency. The nanoencapsulation maintained the anti-Trichomonas vaginalis action of the compound while improving the scavenger action in a DPPH assay. The hydrogels were prepared by thickening nanocapsule suspensions with locust bean gum (3%). The semisolids maintained the nanometric size of the particles and the PhSe₂ content at around the initial concentration (1.0 mg/g). They also displayed non-Newtonian pseudo-plastic behavior and a highly mucoadhesive property. The chorioallantoic membrane method indicated the absence of hemorrhage, coagulation, or lysis. The compound, from both non-encapsulated and nano-based hydrogel delivery systems, remained on the surface of the bovine vaginal mucosa. Therefore, the formulations displayed the intended properties and could be a promising alternative for the treatment of trichomoniasis.

Diphenyl Diselenide Alleviates Tert-Butyl Hydrogen Peroxide-Induced Oxidative Stress and Lipopolysaccharide-Induced Inflammation in Rat Glomerular Mesangial Cells

Hyperglycemia, oxidative stress, and inflammation play key roles in the onset and development of diabetic complications such as diabetic nephropathy (DN). Diphenyl diselenide (DPDS) is a stable and simple organic selenium compound with anti-hyperglycemic, anti-inflammatory, and anti-oxidative activities. Nevertheless, in vitro, the role and molecular mechanism of DPDS on DN remains unknown. Therefore, we investigated the effects of DPDS on tert-butyl hydrogen peroxide (t-BHP)-induced oxidative stress and lipopolysaccharide (LPS)-induced inflammation in rat glomerular mesangial (HBZY-1) cells and explored the underlying mechanisms. DPDS attenuated t-BHP-induced cytotoxicity, concurrent with decreased intracellular ROS and MDA contents and increased SOD activity and GSH content. Moreover, DPDS augmented the protein and mRNA expression of Nrf2, HO-1, NQO1, and GCLC in t-BHP-stimulated HBZY-1 cells. In addition, DPDS suppressed LPS-induced elevations of intracellular content and mRNA expression of interleukin (IL)-6, IL-1β and TNF-α. Furthermore, LPS-induced NFκB activation and high phosphorylation of JNK and ERK1/2 were markedly suppressed by DPDS in HBZY-1 cells. In summary, these data demonstrated that DPDS improves t-BHP-induced oxidative stress by activating the Nrf2/Keap1 pathway, and also improves LPS-induced inflammation via inhibition of the NFκB/MAPK pathways in HBZY-1 cells, suggesting that DPDS has the potential to be developed as a candidate for the prevention and treatment of DN.

Traditional Chinese Medicine Fufang-Zhenzhu-Tiaozhi capsule prevents renal injury in diabetic minipigs with coronary heart disease

BACKGROUND

Renal injury is one of the common microvascular complications of diabetes, known as diabetic kidney disease (DKD) seriously threatening human health. Previous research has reported that the Chinese Medicine Fufang-Zhenzhu-Tiaozhi (FTZ) capsule protected myocardia from injury in diabetic minipigs with coronary heart disease (DM-CHD). And we found significant renal injury in the minipigs. Therefore, we further investigated whether FTZ prevents renal injury of DM-CHD minipig and H₂O₂-induced oxidative injury of HK-2 cells.

METHODS

DM-CHD model was established by streptozotocin injection, high fat/high-sucrose/high-cholesterol diet combined with balloon injury in the coronary artery. Blood lipid profile, fasting blood glucose (FBG), and SOD were measured with kits. The levels of blood urea nitrogen (BUN), serum creatinine (Scr), urine trace albumin (UALB), urine creatinine (UCR) (calculate UACR), cystatin (Cys-C), and β-microglobulin (β-MG) were measured by ELISA kits to evaluate renal function. TUNEL assay was performed to observe the apoptosis. qPCR was used to detect the mRNA expression levels of HO-1, NQO1, and SOD in kidney tissue. The protein expressions of Nrf2, HO-1, NQO1, Bax, Bcl-2, and Caspase 3 in the kidney tissue and HK-2 cells were detected by western blot. Meanwhile, HK-2 cells were induced by H₂O₂ to establish an oxidative stress injury model to verify the protective effect and mechanisms of FTZ.

RESULTS

In DM-CHD minipigs, blood lipid profile and FBG were elevated significantly, and the renal function was decreased with the increase of BUN, Scr, UACR, Cys-c, and β-MG. A large number of inflammatory and apoptotic cells in the kidney were observed accompanied with lower levels of SOD, Bcl-2, Nrf2, HO-1, and NQO1, but high levels of Bax and Cleaved-caspase 3. FTZ alleviated glucose-lipid metabolic disorders and the pathological morphology of the kidney. The renal function was improved and the apoptotic cells were reduced by FTZ administration. FTZ could also enhance the levels of SOD, Nrf2, HO-1, and NQO1 proteins to promote antioxidant effect, down-regulate the expression of Bax and Caspase3, as well as up-regulate the expression of Bcl-2 to inhibit cell apoptosis in the kidney tissue and HK-2 cells.

CONCLUSIONS

We concluded that FTZ prevents renal injury of DM-CHD through activating anti-oxidative capacity to reduce apoptosis and inhibiting inflammation, which may be a new candidate for DKD treatment.

Role of Nrf2 in bisphenol effects: a review study

Bisphenols (BPs), the main endocrine-disrupting chemicals used in polycarbonate plastics, epoxy-phenol resins, and some other manufacturers, have been interestingly focused to find their toxic effects in recent years. Due to the strong relation between bisphenols and some crucial receptors such as ERs, AR, glucocorticoid receptor, THRs, ERRs, hPXR, AhR, and etcetera, the disrupting and oncogenic role of these chemicals on reproductive, respiratory, and circulatory systems and a broad group of body tissues have been investigated. BPs induce oxidant enzymes, exert antioxidant enzymes from body cells, and result in the expression of proinflammatory genes, leading to cell apoptosis and inflammation. To maintain the homeostasis of human body cells, Nrf2, the key regulator of oxidative stress (Ashrafizadeh et al., 2020a; Ashrafizadeh et al., 2020c; Boroumand et al., 2018), confronts BP-induced ROS and RNS through the activation of antioxidant enzymes such as SOD1/2, CAT, GSH, GPX, HO-1, and etcetera. Chemicals and drugs such as LUT, NAC, GEN, L-NMMA, Ph₂Se₂, and GE can regulate the interactions between BPs and Nrf2. Despite the vital role of controlled levels of Nrf2 as an anti-inflammatory and antiapoptotic element, the uncontrolled activity of this transcription factor could lead to cell proliferation and tumorigenesis through NQO1, SLC7a11, Gclm, HMOX1, NQO1 gene activation, and some other genes. To avoid the excessive activity of Nrf2, some protein complexes like CUL3-RBX1-Keap1 (as the primary regulator), β-TrCP, and WDR23 regulate Nrf2's function. It is necessary to note that BPA, as the most famous member, is further reviewed due to its resemblance to the bisphenol family to each other.

The Effect of bisphenol A and Photobiomodulation Therapy on Autophagy-Related Genes Induction in Adipose Tissue-Derived Stem Cells

Introduction: As adipose tissue-derived stem cells (ADSCs) can divide rapidly and be prepared non-invasively, they have extensively been used in regenerative medicine. On the other hand, a new method of therapy, known as photobiomodulation (PHT), has been used to treat many diseases, such as inflammatory conditions, wound healing and pain. Besides, exposure to chemical substances such as bisphenol A (BPA), at low levels, can lead to autophagy. This study investigated the effects of BPA and PHT on the expression of autophagy-related genes, including LC3, NRF2, P62, in rat ADSCs as a model. Methods: ADSCs isolation and purification were confirmed by immunocytochemistry (ICC). The cells were then treated with different concentrations of BPA and also subjected to PHT. Reverse transcription polymerase chain reaction (RT-PCR) was used for the evaluation of LC3, NRF2 and P62 gene expressions. Oil red O staining was used for adipogenic vacuole formation. Result: ICC showed that the isolated cells were CD 49-positive but CD 31 and CD 34-negative. The viability test indicated that the number of live cells after 24 hours in the BPA groups at concentrations of 0, 1, 50, 100 and 200 μM was 100%, 93%, 81%, 72%, and 43% respectively. The difference in cell viability between groups 50, 100 and 200 μM was significant as compared with the control groups (P<0.05). Moreover, in the group with 1 μM concentration of BPA, the expressions of LC3, NRF2 and P62 genes were upregulated. However, in the treatment group at the concentration of 200 μM of BPA, the LC3 gene was expressed, but NRF2 and P62 genes were downregulated. Conclusion: BPA and PHT induce autophagy and adiposeness in ADSCs in a dose-dependent manner.

Naringenin protects swine testis cells from bisphenol A-induced apoptosis via Keap1/Nrf2 signaling pathway

Bisphenol A (BPA) has caused serious pathologies in varying organs of humans and animals, especially reproductive organs. Naringenin (NRG) is a flavanone compound that has shown protective effects against several environmental chemicals through suppression of oxidative stress and activation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Herein, we described the discovery path of NRG inhibition on apoptosis in BPA exposed swine testis (ST) cells through targeting Kelch-like ech-associated protein (Keap1). We found that NRG could specifically bound to the active residues of DGR domain in Keap1, thereby activating Nrf2 signaling pathway, and then increasing the levels of SOD, GPx and CAT, and finally inhibiting oxidative stress and mitochondrial apoptosis induced by BPA in ST cells. Altogether, our results showed that NRG inhibits oxidative stress and mitochondrial apoptosis induced by BPA in ST cells by targeting Keap1/Nrf2 signaling pathway, indicating that NRG could serve as an antagonistic therapy against BPA.

Exogenous Hydrogen Sulfide Plays an Important Role by Regulating Autophagy in Diabetic-Related Diseases

Autophagy is a vital cell mechanism which plays an important role in many physiological processes including clearing long-lived, accumulated and misfolded proteins, removing damaged organelles and regulating growth and aging. Autophagy also participates in a variety of biological functions, such as development, cell differentiation, resistance to pathogens and nutritional hunger. Recently, autophagy has been reported to be involved in diabetes, but the mechanism is not fully understood. Hydrogen sulfide (H₂S) is a colorless, water-soluble, flammable gas with the typical odor of rotten eggs, which has been known as a highly toxic gas for many years. However, it has been reported recently that H₂S, together with nitric oxide and carbon monoxide, is an important gas signal transduction molecule. H₂S has been reported to play a protective role in many diabetes-related diseases, but the mechanism is not fully clear. Recent studies indicate that H₂S plays an important role by regulating autophagy in many diseases including cancer, tissue fibrosis diseases and glycometabolic diseases; however, the related mechanism has not been fully studied. In this review, we summarize recent research on the role of H₂S in regulating autophagy in diabetic-related diseases to provide references for future related research.

Protective effect of alpha-lipoic acid on bisphenol A-induced learning and memory impairment in developing mice: nNOS and keap1/Nrf2 pathway

The adverse effects of bisphenol A (BPA) on learning and memory may be related with oxidative stress, but the mechanisms are unclear. This study aimed to investigate the mechanism of damaged learning and memory caused by BPA through inducing oxidative stress, as well as to explore whether alpha-lipoic acid (ALA) show a protective action. Female mice were exposed to 0.1 μg/mL BPA, 0.2 μg/mL BPA, 0.6 mg/mL ALA, and 0.2 BPA + ALA through drinking water for 8 weeks. The results showed that ALA protected against the impairment of spatial, recognition, and avoidance memory caused by BPA. ALA replenished the reduce of hippocampus coefficient, serum estradiol (E2) level, and hippocampal neurotransmitters levels induced by BPA. ALA alleviated BPA-induced oxidative stress and hippocampal histological changes. BPA exposure reduced the levels of synaptic structural proteins and PKC/ERK/CREB pathway proteins, and ALA improved these reductions. ALA altered the protein levels of nNOS and keap1/Nrf2 pathway affected by BPA. Our results suggested that impairments of learning and memory caused by BPA was related to the damage of hippocampal synapses mediated by oxidative stress, and ALA protected learning and memory by reducing the oxidative stress induced by BPA through regulating the nNOS and keap1/Nrf2 pathway.

Resveratrol Butyrate Esters Inhibit BPA-Induced Liver Damage in Male Offspring Rats by Modulating Antioxidant Capacity and Gut Microbiota

Resveratrol can affect the physiology or biochemistry of offspring in the maternal-fetal animal model. However, it exhibits low bioavailability in humans and animals. Fifteen-week SD pregnant female rats were orally administered bisphenol A (BPA) and/or resveratrol butyrate ester (RBE), and the male offspring rats (n = 4-8 per group) were evaluated. The results show that RBE treatment (BPA + R30) compared with the BPA group can reduce the damage caused by BPA (p < 0.05). RBE enhanced the expression of selected genes and induced extramedullary hematopoiesis and mononuclear cell infiltration. RBE increased the abundance of S24-7 and Adlercreutzia in the intestines of the male offspring rats, as well as the concentrations of short-chain fatty acids (SCFAs) in the feces. RBE also increased the antioxidant capacity of the liver by inducing Nrf2, promoting the expression of HO-1, SOD, and CAT. It also increased the concentration of intestinal SCFAs, enhancing the barrier formed by intestinal cells, thereby preventing BPA-induced metabolic disruption in the male offspring rats, and reduced liver inflammation. This study identified a potential mechanism underlying the protective effects of RBE against the liver damage caused by BPA exposure during the peri-pregnancy period, and the influence of the gut microbiota on the gut-liver axis in the offspring.

Toxicology and pharmacology of synthetic organoselenium compounds: an update

Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.

Diphenyl diselenide ameliorates diabetic nephropathy in streptozotocin-induced diabetic rats via suppressing oxidative stress and inflammation

Oxidative stress and inflammation are implicated in the occurrence and progression of diabetic nephropathy (DN). Diphenyl diselenide (DPDS) is a stable and simple diaryl diselenide with anti-hyperglycemic, anti-inflammatory, and antioxidant activities. However, the effects of DPDS on DN are still unclear to date. Herein, we aimed to explore whether DPDS could improve renal dysfunction in streptozotocin (STZ)-induced diabetic rats and its underlying mechanisms. STZ-induced DN rats were administered with DPDS (5 or 15 mg/kg) or metformin (200 mg/kg) once daily by intragastric gavage for 12 weeks. DPDS supplementation significantly improved hyperglycemia, glucose intolerance, dyslipidemia, and the renal pathological abnormalities, concurrent with significantly reduced serum levels of creatinine, urea nitrogen, urine volume, and urinary levels of micro-albumin, β2-microglobulin and N-acetyl-glucosaminidase activities. Moreover, DPDS effectively promoted the activities of antioxidant enzymes, and reduced the levels of MDA and pro-inflammatory factors in serum and the kidney. Furthermore, DPDS supplementation activated the renal Nrf2/Keap1 signaling pathway, but attenuated the high phosphorylation levels of NFκB, JNK, p38 and ERK1/2. Altogether, the current study indicated for the first time that DPDS ameliorated STZ-induced renal dysfunction in rats, and its mechanism of action may be attributable to suppressing oxidative stress via activating the renal Nrf2/Keap1 signaling pathway and mitigating inflammation by suppressing the renal NFκB/MAPK signaling pathways, suggesting a potential therapeutic approach for DN.

Impaction of factors associated with oxidative stress on the pathogenesis of gestational hypertension and preeclampsia: A Chinese patients based study

We aimed to investigate the effect of Kelch-like ECH-associated protein 1/NF-E2 p45-related factor 2 (Keap1/Nrf2) pathway on the biological function of trophoblast cells in oxidative stress model at the cellular level, and analyzed the expression level and clinical significance of Keap1/Nrf2 pathway and related antioxidant factors in placental tissues of Preeclampsia (PE) patients at clinical level. In present study, we found that under hypoxia/reoxygenation conditions, the activity of oxidative stress-related enzymes (CAT, GSH-Px, SOD) in HTR8/SVneo cells was significantly lower than that before treatment (P < .01). The activities of CAT, GSH-Px and SOD in HTR8/SVneo cells in SiRNA+H/R group decreased significantly (P < .01), indicating the important defense effect of Keap1/Nrf2 signaling pathway in oxidative stress. As a control group of Nrf2 SiRNA+H/R group, Si-NC+H/R group had CAT, GSH-Px and SOD activities decreasing, which was similar to that in H/R group. Moreover, the activities of oxidative stress-related active enzymes in patients with PE were further confirmed by detecting and comparing the activities of CAT, GSH-Px and SOD in placental tissues. The results showed that the activity of SOD (P < .001), GSH-Px (P < .01) and CAT (P < .01) in placental tissues of patients with PE were significant different from those of normal placental tissues. The expression level of Keap1 in placenta of patients with PE was slightly lower than that of normal placenta. While the expression of Nrf2 in placenta of patients with PE was significantly higher than that of normal placenta. HO-1 expression in placenta of patients with PE was significantly higher than that of normal placenta. These results implicate the importance of Keap-1/Nrf2 pathway in PE.

Diphenyl diselenide protects motor neurons through inhibition of microglia-mediated inflammatory injury in amyotrophic lateral sclerosis

Microglia-mediated neuroinflammatory response and neuron damage are considered as a self-propelling progressive cycle, being strongly implicated in the progression of neurodegeneration in amyotrophic lateral sclerosis (ALS). Diphenyl diselenide (DPDS), a simple organoselenium compound, has been known to possess multiple pharmacological properties. The purpose of this study was to explore the neuroprotective effects of DPDS against microglia-mediated neuroinflammatory injury in ALS models. We found that DPDS pretreatment inhibited LPS-induced activation of IκB/NF-κB pathway and subsequent release of proinflammatory factors from activated primary hSOD1^G93A microglia. Moreover, DPDS suppressed NLRP3 inflammasome activation by decreasing protein nitration via reduction in NO and ROS levels, whose low levels are related to NF-κB inhibition responsible for iNOS and NOX2 down-regulations, respectively. Notably, DPDS-mediated ROS attenuation was not linked to Nrf2 activation in this cellular model. Furthermore, in the absence of activated microglia, DPDS has no significant effect on the individual hSOD1^G93A-NSC34 cells; however, in in vitro neuron-microglia conditional culture and co-culture experiments, DPDS protected motor neurons from neurotoxic damage caused by LPS or BzATP-stimulated microglia activation. Above observations suggest that DPDS-afforded neuroprotection is linked to inhibition of microglia-mediated neuroinflammation in ALS, which was further verified in vivo as shown by improvements of motor deficits, prolonged survival, and reduction of motor neuron loss and reactive microgliosis in hSOD1^G93A transgenic mouse. Altogether, our results show that DPDS elicited neuroprotection in ALS models through inactivation of microglia by inhibiting IκB/NF-κB pathway and NLRP3 inflammasome activation, suggesting that DPDS may be a promising candidate for potential therapy for ALS.

Opioid System Contributes to the Trifluoromethyl-Substituted Diselenide Effectiveness in a Lifestyle-Induced Depression Mouse Model

Energy-dense foods and ethanol consumption are associated with mood disorders. m-Trifluoromethyl-diphenyl diselenide [(m-CF₃-PhSe)₂] has been a prominent pharmacological target due to its antidepressant-like effects. This study investigated if the modulation of opioid and glucocorticoid receptors and its well-known antioxidant property contribute to the (m-CF₃-PhSe)₂ antidepressant-like effect in young mice subjected to an energy-dense diet and ethanol intake. Swiss male mice [postnatal day (PND) 25] were exposed to an energy-dense diet (containing 20% fat and 20% carbohydrate) or standard chow until the PND 67. Mice received ethanol (2 g/kg) or water administration (3 times a week, intragastrically [i.g.]) from PND 45 to PND 60. After that, mice received (m-CF₃-PhSe)₂ (5 mg/kg/day; i.g) or vegetal oil administration from PND 60 to 66. Mice performed the behavioral tests to evaluate the depressive-like phenotype. The results showed that individually neither an energy-dense diet nor ethanol group induced a depressive-like phenotype, but the association of both induced this phenotype in young mice. Oxidative stress was characterized by the increase of malondialdehyde, the decrease in the superoxide dismutase activity, and non-protein sulfhydryl levels in the cerebral cortex of depressive-like mice. Depressive-like mice showed an increase in the protein levels of opioid receptors and depletion in those of glucocorticoid. (m-CF₃-PhSe)₂ abolished depressive-like phenotype and oxidative stress as well as modulated the levels of glucocorticoid and opioid receptors. In conclusion, the modulation of opioid and glucocorticoid receptors and the antioxidant property contributed to the (m-CF₃-PhSe)₂ antidepressant-like effect in young mice exposed to an energy-dense diet and ethanol intake.

In vitro evaluation of the hepatic lipid accumulation of bisphenol analogs: A high-content screening assay

Bisphenol A (BPA) has a variety of adverse effects on human health; therefore, BPA analogs are increasingly used as replacements. Notably, recent studies have revealed that BPA exposure induced hepatic lipid accumulation, but few studies are available regarding the similar effects of other bisphenol analogues (BPs). Thus, in the present study, a high-content screening (HCS) assay was performed to simultaneously evaluate the hepatic lipid accumulation of 13 BPs in vitro. The BPs induced lipid deposition in HepG2 cells ranking as below: 4,4'-thiodiphenol (TDP) < bisphenol S (BPS) < 4,4'-dihydroxybenzophenone (DHBP) < tetrabromobisphenol A (TBBPA) < tetrachlorobisphenol A (TCBPA) < bisphenol E (BPE) < bisphenol F (BPF) < bisphenol B (BPB) < bisphenol AF (BPAF) < bisphenol A (BPA) < bisphenol C (BPC) < tetramethylbisphenol A (TMBPA) < bisphenol AP (BPAP). Meanwhile, Oil Red O staining and triacylglycerol detection further validated the lipid accumulation elicited by the latter 8 BPs, which exhibited the more significant effects on lipid deposition. Mechanistically, significantly increased expressions of genes involved in fatty acid synthesis and nuclear receptors and decreased levels of genes associated with fatty acid β-oxidation were observed under BPs treatment. Therefore, the present work is the first to systematically provide direct evidence for BPs-induced hepatic lipid accumulation in vitro via HCS, which can be helpful for safety assessments of BPs.

Females are more susceptible than male mice to thermal hypernociceptive behavior induced by early-life bisphenol-A exposure: Effectiveness of diphenyl diselenide

Humans are ubiquitously exposed to bisphenol A (BPA), one of the most used synthetic monomers for manufacturing polycarbonate plastics. BPA exposure leads to abnormal nociceptive perception and neuroinflammation in rodents. This study investigated whether diphenyl diselenide (PhSe)₂, a pleiotropic selenium-containing molecule, would be effective against the hypernociceptive behavior induced by the early-life BPA exposure to mice. Three-week-old male and female Swiss mice received intragastrically BPA (5 mg/kg) from 21^st to 60^th postnatal day. After, the mice received by the intragastric route (PhSe)₂ (1 mg/kg) once a day for seven days. After the last day of treatment, the mice performed the hot plate and tail immersion tests. The cerebral cortex samples were used to determine the levels of proteins related to apoptosis and inflammation. The results demonstrated that females were more susceptible than male mice to thermal hypernociception induced by early-life exposure to BPA. (PhSe)₂ was effective against the reduction in the latency to paw and tail withdrawal induced by BPA exposure in female mice. Furthermore, (PhSe)₂ restored the impairment in the levels of inflammatory proteins (COX-2, IL-1β, and p-JNK/JNK) but not those of apoptosis in the cerebral cortex of female mice exposed to BPA. Collectively, these data showed that females were more susceptible to thermal hypernociceptive behavior induced by early-life exposure to BPA than male mice. The administration of (PhSe)₂ reduced thermal hypernociceptive behavior, a sex independent effect, in BPA-exposed mice. (PhSe)₂ modulated inflammatory protein levels in the cerebral cortex of female mice exposed to BPA.

Mechanism of oxidative stress and Keap-1/Nrf2 signaling pathway in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease common in premature infants and is one of the leading causes of disability and death in newborns. The Keap-1/Nrf2 signaling pathway plays an important role in antioxidant and anti-inflammatory.Ten clean-grade, healthy pregnant Sprague-Dawley rats (purchased from Experimental Animal Center of Peking university, China) naturally gave birth to 55 neonatal rats from which 40 were selected and randomly divided into a hyperoxia group and a control group (N = 20, each). Thirty-two BPD patient samples are from Neonatal Department of the second Hospital of Jilin University from November 30, 2016 to May 1 2019.In present study, we observed that lung tissues of the control group did not undergo obvious pathological changes, whereas in the hyperoxia group, lung tissues had disordered structures. With increased time of hyperoxia exposure, the alveolar wall became attenuated. Under hypoxia conditions, the activity of oxidative stress-related enzymes (CAT, GSH-Px, SOD) in lung samples was significantly lower than that before treatment. The expression level of Keap1 mRNA and protein in the hyperoxia group was slightly lower than that of control group. The expression of Nrf2 and HO-1 mRNA and protein in the hyperoxia group was significantly higher than that of control group. For the infants with BPD, we found that the activity of SOD, GSH-Px, and CAT was significantly different from those of control group.We constructed a premature BPD animal model and found the abnormal of oxidative stress in different groups and the expression levels of Keap1/Nrf2 signaling pathway-related molecules, and we validated the results in premature infants with BPD.

Regulation of Keap-1/Nrf2 Signaling Pathway Is Activated by Oxidative Stress in Patients with Premature Rupture of Membranes

Background

The potential mechanisms underlying premature rupture of membrane (PROM) is still unknown. The aim of this study was to determine the role of Keap-1/Nrf2 signaling pathway activation by oxidative stress in patients with preterm premature rupture of membranes.

Material/Methods

Placental tissues from preterm premature rupture of membranes (PPROM) (n=20), full-term premature rupture of membranes (FPROM) (n=20), and normal-term births (n=20) were collected and amniotic tissues were separated from the placental tissues from pregnant women at Shandong Provincial Qianfoshan Hospital. RT-PCR and Western blot were used to detect the levels of factors in the Keap-1/Nrf2 signaling pathway. To investigate the roles of Nrf2, we downregulated Nrf2 expression using siRNA in primary human amniotic epithelial (HAE) cells.

Results

Among the control group, FPROM group, and PPROM group, the reactive oxygen species (ROS) levels were significantly increased in the FPROM and PPROM groups. The differences indicated higher levels of oxidative stress in amniotic tissues with FPROM and PPROM after downregulation of si-Nrf2 in HAE cells. Antioxidants were lower in amniotic tissues with the FPROM group and PPROM group than in the control group. The antioxidant enzymes catalase (CAT), glutathione (GSH), glutathione peroxidase (GSHPx), and superoxide dismutases (SOD1 and SOD2) were examined in amniotic tissues. We found that the ROS levels were significantly increased after downregulation of si-Nrf2 compared with the control group. We found that the expression of Heme Oxygenase-1 (HO-1) and Glycogen Synthase Kinase-3b (GSK-3b), which is critical in the Keap-1/Nrf2 signaling pathway, increased significantly after downregulation of si-Nrf2 in HAE cells.

Conclusions

We found that increased ROS levels and decreased antioxidant enzymes in the PPROM and FPROM patients compared with the control group.

Synthesis of Novel Selenocyanates and Evaluation of Their Effect in Cultured Mouse Neurons Submitted to Oxidative Stress

Herein, we report the synthesis of novel selenocyanates and assessment of their effect on the oxidative challenge elicited by hydrogen peroxide (H₂O₂) in cultured mouse neurons. First, α-methylene-β-hydroxy esters were prepared as precursors of allylic bromides. A reaction involving the generated bromides and sodium selenocyanate was conducted to produce the desired selenocyanates (3a-f). We next prepared cultures of neurons from 7-day-old mice (n = 36). H₂O₂ (10^-5 M) was added into the culture flasks as an oxidative stress inducer, alone or combined with one of each designed compounds. (PhSe)₂ was used as a positive control. It was carried out assessment of lipid (thiobarbituric acid reactive species, 4-hydroxy-2'-nonenal, 8-isoprostane), DNA (8-hydroxy-2'-deoxyguanosine), and protein (carbonyl) modification parameters. Finally, catalase and superoxide dismutase activities were also evaluated. Among the compounds, 3b, 3d, and 3f exhibited the most pronounced pattern of antioxidant activity, similar to (PhSe)₂. These novel aromatic selenocyanates could be promising to be tried in most sophisticated in vitro studies or even at the preclinical level.

Oxidative stress, ion concentration change and immune response in gills of common carp (Cyprinus carpio) under long-term exposure to bisphenol A

Bisphenol A (BPA) is a well-known phenolic environmental estrogen, widely distributed in the aquatic environment, which poses a toxic risk to the health of aquatic organisms. This study aimed to assess the effect of BPA on common carp gills by analyzing oxidative stress, ion equilibrium and immune response. Fish were exposed to five concentrations of BPA (0, 0.01, 0.1, 0.5, and 2 mg/L) for 30 days. Then gills were collected to assay biochemical parameters and gene expression. The results showed that BPA could decrease the levels of total antioxidant capacity (T-AOC), catalase (CAT), glutathione (GSH) and glutathione S-transferase (GST) and increase the levels of superoxide dismutase (SOD), malondialdehyde (MDA) and 8-hydroxy-2 deoxyguanosine (8-OHdG). The gene expression showed that BPA (2 mg/L) could affect the nuclear erythroid 2-related factor 2 (nrf2) signaling pathway, upregulate the gene expression of nrf2 and heme oxygenase 1 (ho-1). Meanwhile, BPA was found to change the activity of Na⁺/K⁺ ATPase, and increased the concentrations of Na⁺ and Ca²⁺ in gills of common carp. Also, high BPA concentration (0.5 or 2 mg/L) exposure increased the activity of alkaline phosphatase (AKP), blocked mRNA level of lysozyme-c (c-lyz), activated Toll-like receptors (TLRs) signaling pathway, enhanced the mRNA levels of toll-like receptor 2 (tlr2), receptor 4 (tlr4), myeloid differentiation factor 88 (myd88), interferon regulatory factor 3 (irf3), interleukin 1β (il-1β), interleukin 6 (il-6) and interleukin 10 (il-10). Overall, these results suggested that high BPA could induce oxidative damage, ion imbalance, immunosuppression and inflammatory response in gills of common carp.

New strategy of bone marrow mesenchymal stem cells against oxidative stress injury via Nrf2 pathway: oxidative stress preconditioning

Clinically, bone marrow mesenchymal stem cells (BMSCs) have been used in treatment of many diseases, but the local oxidative stress (OS) of lesion severely limits the survival of BMSCs, which reduces the efficacy of BMSCs transplantation. Therefore, enhancing the anti‐OS stress ability of BMSCs is a key breakthrough point. Preconditioning is a common protective mechanism for cells or body. Here, the aim of this study was to investigate the effects of OS preconditioning on the anti‐OS ability of BMSCs and its mechanism. Fortunately, OS preconditioning can increase the expression of superoxide dismutase, catalase, NQO1, and heme oxygenase 1 through the nuclear factor erythroid 2‐related factor 2 pathway, thereby decreased the intracellular reactive oxygen species (ROS) levels, relieved the damage of ROS to mitochondria, DNA and cell membrane, enhanced the anti‐OS ability of BMSCs, and promoted the survival of BMSCs under OS.

Diphenyl diselenide abrogates brain oxidative injury and neurobehavioural deficits associated with pesticide chlorpyrifos exposure in rats

Exposure to pesticide chlorpyrifos (CPF) is associated with neurodevelopmental toxicity both in humans and animals. Diphenyl diselenide (DPDS) is a simple synthetic organoselenium well reported to possess antioxidant, anti-inflammatory and neuroprotective effects. However, there is paucity of information on the beneficial effects of DPDS on CPF-mediated brain injury and neurobehavioural deficits. The present study investigated the neuroprotective mechanism of DPDS in rats sub-chronically treated with CPF alone at 5 mg/kg body weight or orally co-treated with DPDS at 2.5 and 5 mg/kg body weight for 35 consecutive days. Endpoint analyses using video-tracking software in a novel environment revealed that co-treatment with DPDS significantly (p < 0.05) protected against CPF-mediated locomotor and motor deficits precisely the decrease in maximum speed, total distance travelled, body rotation, absolute turn angle, forelimb grip strength as well as the increase in negative geotaxis and incidence of fecal pellets. The enhancement in the neurobehavioral activities of rats co-treated with DPDS was verified by track plot analyses. Besides, DPDS assuaged CPF-induced decrease in acetylcholinesterase and antioxidant enzymes activities and the increase in myeloperoxidase activity and lipid peroxidation level in the mid-brain, cerebral cortex and cerebellum of the rats. Histologically, DPDS co-treatment abrogated CPF-mediated neuronal degeneration in the cerebral cortex, dentate gyrus and cornu ammonis3 in the treated rats. In conclusion, the neuroprotective mechanisms of DPDS is related to the prevention of oxidative stress, enhancement of redox status and acetylcholinesterase activity in brain regions of the rats. DPDS may be a promising chemotherapeutic agent against brain injury resulting from CPF exposure.