Organic silicon protects human neuroblastoma SH-SY5Y cells against hydrogen peroxide effects

Reactive Oxygen Species Modulate Th17/Treg Balance in Chlamydia psittaci Pneumonia via NLRP3/IL-1β/Caspase-1 Pathway Differentiation

Chlamydia psittaci pneumonia (CPP) is a lung disease caused by the infection with the Chla-mydia psittaci bacterium, which can lead to severe acute respiratory distress syndrome and systemic symptoms. This study explored the specific mechanisms underlying the impact of reactive oxygen species (ROS) on the Th17/Treg balance in CPP. The levels of ROS and the differentiation ratio of Th17/Treg in the peripheral blood of healthy individuals and CPP patients were measured using ELISA and flow cytometry, respectively. The association between the ROS levels and Th17/Treg was assessed using Pearson correlation analysis. The ROS levels and the Th17/Treg ratio were measured in CD4+ T cells following H2O2 treatment and NLRP3 inhibition. The effects of H2O2 treatment and NLRP3 inhibition on the NLRP3/IL-1β/caspase-1 pathway were observed using immunoblotting. Compared to the healthy group, the CPP group exhibited increased levels of ROS in the peripheral blood, an elevated ratio of Th17 differentiation, and a decreased ratio of Treg differentiation. ROS levels were positively correlated with the Th17 cell proportion but negatively correlated with the Treg cell proportion. The ROS levels and NLRP3/IL-1β/caspase-1 expression were up-regulated in CD4+ T cells after H2O2 treatment. Furthermore, there was an increase in Th17 differentiation and a decrease in Treg differentiation. Conversely, the NLRP3/IL-1β/caspase-1 pathway inhibition reversed the effects of H2O2 treatment, with no significant change in the ROS levels. ROS regulates the Th17/Treg balance in CPP, possibly through the NLRP3/IL-1β/caspase-1 pathway. This study provides a new perspective on the development of immunotherapy for CPP.

Cell Model of Depression: Reduction of Cell Stress with Mirtazapine

Depression is a very prevalent and complex disease. This condition is associated with a high rate of relapse, making its treatment a challenge. Thus, an intensive investigation of this disease and its treatment is necessary. In this work, through cell viability assays (MTT and neutral red assays) and alkaline comet assays, we aimed to test the induction of stress in human SH-SY5Y cells through the application of hydrocortisone and hydrogen peroxide and to test the reversal or attenuation of this stress through the application of mirtazapine to the cells. Our results demonstrated that hydrogen peroxide, and not hydrocortisone, can induce cellular stress, as evidenced by DNA damage and a global cellular viability reduction, which were alleviated by the antidepressant mirtazapine. The establishment of a cellular model of depression through stress induction is important to study new possibilities of treatment of this disease using cell cultures.

Acacia catechu Willd. Extract Protects Neuronal Cells from Oxidative Stress-Induced Damage

Oxidative stress (OS) and the resulting reactive oxygen species (ROS) generation and inflammation play a pivotal role in the neuronal loss occurring during the onset of neurodegenerative diseases. Therefore, promising future drugs that would prevent or slow down the progression of neurodegeneration should possess potent radical-scavenging activity. Acacia catechu Willd. heartwood extract (AC), already characterized for its high catechin content, is endowed with antioxidant properties. The aim of the present study was to assess AC neuroprotection in both human neuroblastoma SH-SY5Y cells and rat brain slices treated with hydrogen peroxide. In SH-SY5Y cells, AC prevented a decrease in viability, as well as an increase in sub-diploid-, DAPI positive cells, reduced ROS formation, and recovered the mitochondrial potential and caspase-3 activation. AC related neuroprotective effects also occurred in rat brain slices as a reversal prevention in the expression of the main proteins involved in apoptosis and signalling pathways related to calcium homeostasis following OS-mediated injury. Additionally, unbiased quantitative mass spectrometry allowed for assessing that AC partially prevented the hydrogen peroxide-induced altered proteome, including proteins belonging to the synaptic vesicle fusion apparatus. In conclusion, the present results suggest the possibility of AC as a nutraceutical useful in preventing neurodegenerative diseases.

Functional Meat Products as Oxidative Stress Modulators: A Review

High meat consumption has been associated with increased oxidative stress mainly due to the generation of oxidized compounds in the body, such as malondialdehyde, 4-hydroxy-nonenal, oxysterols, or protein carbonyls, which can induce oxidative damage. Meat products are excellent matrices for introducing different bioactive compounds, to obtain functional meat products aimed at minimizing the pro-oxidant effects associated with high meat consumption. Therefore, this review aims to summarize the concept and preparation of healthy and functional meat, which could benefit antioxidant status. Likewise, the key strategies regarding meat production and storage as well as ingredients used (e.g., minerals, polyphenols, fatty acids, walnuts) for developing these functional meats are detailed. Although most effort has been made to reduce the oxidation status of meat, newly emerging approaches also aim to improve the oxidation status of consumers of meat products. Thus, we will delve into the relation between functional meats and their health effects on consumers. In this review, animal trials and intervention studies are discussed, ascertaining the extent of functional meat products' properties (e.g., neutralizing reactive oxygen species formation and increasing the antioxidant response). The effects of functional meat products in the frame of diet-gene interactions are analyzed to 1) discover target subjects that would benefit from their consumption, and 2) understand the molecular mechanisms that ensure precision in the prevention and treatment of diseases, where high oxidative stress takes place. Long-term intervention-controlled studies, testing different types and amounts of functional meat, are also necessary to ascertain their positive impact on degenerative diseases.

Silicon-containing water intake confers antioxidant effect, gastrointestinal protection, and gut microbiota modulation in the rodents

We explored the effects of silicon-containing water (BT) intake on gastrointestinal function and gut microbiota. BT was obtained by pressuring tap water through silicon minerals (mullite, Al₆Si₂O₁₃) column. BT decreased H₂O₂ chemiluminescence counts, indicating its antioxidant activity. Four weeks of BT drinking increased H₂O₂ scavenging activity and glutathione peroxidase activity of plasma. BT drinking did not affect the body weight but significantly reduced the weight of feces and gastrointestinal motility. BT drinking significantly suppressed pylorus ligation enhanced gastric juice secretion, gastric reactive oxygen species amount, erythrocyte extravasation, IL-1β production by infiltrating leukocyte, and lipid peroxidation within gastric mucosa. Data from 16S rRNA sequencing revealed BT drinking significantly increased beneficial flora including Ruminococcaceae UCG-005, Prevotellaceae NK3B31, Weissella paramesenteroides, Lactobacillus reuteri, and Lactobacillus murinus and decreased harmful flora including Mucispirillum, Rodentibacter, and Staphylococcus aureus. This study pioneerly provided scientific evidences for the potential effects of water-soluble forms of silicon intake on antioxidant activity, gastrointestinal function, and gut microbiota modulation.

Olive Leaves and Hibiscus Flowers Extracts-Based Preparation Protect Brain from Oxidative Stress-Induced Injury

Oxidative stress (OS) arising from tissue redox imbalance, critically contributes to the development of neurodegenerative disorders. Thus, natural compounds, owing to their antioxidant properties, have promising therapeutic potential. Pres phytum (PRES) is a nutraceutical product composed of leaves- and flowers-extracts of Olea europaea L. and Hibiscus sabdariffa L., respectively, the composition of which has been characterized by HPLC coupled to a UV-Vis and QqQ-Ms detector. As PRES possess antioxidant, antiapoptotic and anti-inflammatory properties, the aim of this study was to assess its neuroprotective effects in human neuroblastoma SH-SY5Y cells and in rat brain slices subjected to OS. PRES (1–50 µg/mL) reverted the decrease in viability as well as the increase in sub-diploid-, DAPI-and annexin V-positive-cells, reduced ROS formation, recovered the mitochondrial potential and caspase-3 and 9 activity changes caused by OS. PRES (50–100 µg/mL) neuroprotective effects occurred also in rat brain slices subjected to H₂O₂ challenge. Finally, as the neuroprotective potential of PRES is strictly related to its penetration into the brain and a relatively good pharmacokinetic profile, an in-silico prediction of its components drug-like properties was carried out. The present results suggest the possibility of PRES as a nutraceutical, which could help in preventing neurodegenerative diseases.

Discovery of new potent dual sigma receptor/GluN2b ligands with antioxidant property as neuroprotective agents

Among several potential applications, sigma receptors (σRs) can be used as neuroprotective agents, antiamnesic, antipsychotics and against other neurodegenerative disorders. On the other hands, antagonists of the GluN2b-subunit-containing-N-methyl-D-aspartate (NMDA) receptors are of major interest for the same purpose, being this subunit expressed in specific areas of the central nervous system and responsible for the excitatory regulation of nerve cells. Under these premises, we have synthesized and biologically tested novel hybrid derivatives obtained from the combination of phenyloxadiazolone and dihydroquinolinone scaffolds with different amine moieties, peculiar of σ2R ligands. Most of the new ligands exhibited a pan-affinity towards both σR subtypes and high affinity against GluN2b subunit. The most promising compounds belong to the dihydroquinolinone series, with the best affinity profile for the cyclohexylpiperazine derivative 28. Investigation on their biological activity showed that the new compounds were able to protect SH-SY5Y cells against oxidative stress induced by hydrogen peroxide treatment. These results proved that our dual σR/GluN2b ligands have beneficial effects in a model of neuronal oxidative stress and can represent strong candidate pharmacotherapeutic agents for minimizing oxidative stress-induced neuronal injuries.

Acer okamotoanum protects SH-SY5Y neuronal cells against hydrogen peroxide-induced oxidative stress

Oxidative stress by over-production of reactive oxygen species (ROS) in brain is widely known as a cause of neurodegenerative disease. We investigated protective effects of Acer okamotoanum against oxidative stress by hydrogen peroxide (H₂O₂) in SH-SY5Y neuronal cells. Acer okamotoanum reduced ROS production and lactate dehydrogenase release in H₂O₂-induced SH-SY5Y cells, resulting in elevation of cell viability. To elucidate protective mechanisms, we measured inflammation and apoptosis-associated protein expressions. Treatment with A. okamotoanum dose-dependently decreased pro-inflammatory proteins such as inducible nitric oxide synthase and cyclooxygenase-2. Treatment with A. okamotoanum showed down-regulation of pro-apoptosis genes such as cleaved caspase-3, cleaved caspase-9, and Bax, and up-regulation of anti-apoptosis protein including Bcl-2, in H₂O₂-induced SH-SY5Y cells. We demonstrated potential anti-inflammatory and anti-apoptotic effect of A. okamotoanum in H₂O₂-induced SH-SY5Y cells. These results suggest that A. okamotoanum may possess neuroprotective potential, but further study is necessary to elucidate its pharmacological effects in neurodegenerative diseases.

Silicic Acid and Beer Consumption Reverses the Metal Imbalance and the Prooxidant Status Induced by Aluminum Nitrate in Mouse Brain

BACKGROUND

Emerging evidence suggests that by affecting mineral balance, aluminum (Al) may enhance some events associated with neurodegenerative diseases.

AIM

To examine the effect of Al(NO3)3 exposure on brain Al, cooper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), silicon (Si), and zinc (Zn) levels, and the metal-change implication in brain oxidant and inflammatory status.

METHODS

Four groups of six-week-old male NMRI mice were treated for three months: i) controls, administrated with deionized water; ii) Al, which received Al(NO3)3; iii) Al+silicic acid, which were given Al(NO3)3 plus silicic acid; and iv) Al+beer, which received Al(NO3)3 plus beer.

RESULTS

Brain Al and TBARS levels and TNFα and GPx expressions increased, while Cu, Mn, and Zn levels, and catalase and CuZn-SOD expression decreased (at least, p < 0.05) in Al versus control animals. Al, Si, and TBARS levels and TNFα expression decreased (p < 0.05) in Al+silicic acid and Al+beer specimens while Cu, Mn, and Zn levels and antioxidant expression increased versus the Al group. Brain Al levels correlated negatively with those of Cu, Fe, Mn, and Zn, and catalase, CuZn-SOD, and GPx enzyme expressions but positively with Si and TBARS levels and TNFα expression. Two components of the principal component analysis (PCA) explained 71.2% of total data variance (p < 0.001). PCA connected the pro-oxidant markers with brain Al content, while brain Zn and Cu levels were closer to antioxidant enzyme expression.

CONCLUSION

Administration of Al(NO3)3 induced metal imbalance, inflammation, and antioxidant status impairment in the brain. Those effects were blocked to a significant extent by silicic acid and beer administration.

Silicon Alleviates Nonalcoholic Steatohepatitis by Reducing Apoptosis in Aged Wistar Rats Fed a High-Saturated Fat, High-Cholesterol Diet

Background: Lipoapoptosis has been identified as a key event in the progression of nonalcoholic fatty liver disease (NAFLD), and hence, antiapoptotic agents have been recommended as a possible effective treatment for nonalcoholic steatohepatitis (NASH). Silicon, included in meat as a functional ingredient, improves lipoprotein profiles and liver antioxidant defenses in aged rats fed a high-saturated fat, high-cholesterol diet (HSHCD). However, to our knowledge, the antiapoptotic effect of this potential functional meat on the liver has never been tested.Objective: This study was designed to evaluate the effect of silicon on NASH development and the potential antiapoptotic properties of silicon in aged rats.Methods: One-year-old male Wistar rats weighing ∼500 g were fed 3 experimental diets containing restructured pork (RP) for 8 wk: 1) a high-saturated fat diet, as an NAFLD control, with 16.9% total fat, 0.14 g cholesterol/kg diet, and 46.8 mg SiO₂/kg (control); 2) the HSHCD as a model of NASH, with 16.6% total fat, 16.3 g cholesterol/kg diet, and 46.8 mg SiO₂/kg [high-cholesterol diet (Chol-C)]; and 3) the HSHCD with silicon-supplemented RP with amounts of fat and cholesterol identical to those in the Chol-C diet, but with 750 mg SiO₂/kg (Chol-Si). Detailed histopathological assessments were performed, and the NAFLD activity score (NAS) was calculated. Liver apoptosis and damage markers were evaluated by Western blotting and immunohistochemical staining.Results: Chol-C rats had a higher mean NAS (7.4) than did control rats (1.9; P < 0.001). The score in Chol-Si rats (5.4) was intermediate and different from that in both other groups (P < 0.05). Several liver apoptosis markers-including hepatocyte terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate (dUTP) nick end labeling, cytosolic cytochrome c, apoptosis-inducing factor, caspases 9 and 3, and the mitochondrial Bcl-2-associated X protein (BAX)-to-B-cell lymphoma 2 (BCL2) ratio-were 9-45% lower in Chol-Si than in Chol-C rats (P < 0.05) and did not differ from values in the control group.Conclusions: Supplemental silicon substantially affects NASH development in aged male Wistar rats fed an HSHCD by partially blocking apoptosis. These results suggest that silicon-enriched RP could be used as an effective nutritional strategy in preventing NASH.

Hydrogen peroxide modifies both activity and isoforms of acetylcholinesterase in human neuroblastoma SH-SY5Y cells

The involvement of cholinergic system and the reactive oxygen species (ROS) in the pathogenesis of some degenerative diseases has been widely reported; however, the specific impact of hydrogen peroxide (H₂O₂) on the acetylcholinesterase (AChE) activity as well as AChE isoform levels has not been clearly established. Hence, the purpose of present study is to clarify whether H₂O₂ alters these parameters.

Human neuroblastoma SH-SY5Y cells were treated with H₂O₂ (1–1000 µM) for 24 h and AChE activity and AChE and cytochrome c levels were evaluated. AChE activity was strongly increased from 1 µM to 1000 µM of H₂O_2. The results of the kinetic study showed that H₂O₂ affected Vmax but not Km; and also that H₂O₂ changed the sigmoid kinetic observed in control samples to hyperbolic kinetic. Thus, results suggest that H₂O₂ acts as an allosteric activators. In addition, H₂O₂, (100–1000 µM) reduced the total AChE content and modified its isoform profile (mainly 50-, 70-, and 132-kDa)·H₂O₂ from 100 µM to 1000 µM induced cytochrome c release confirming cell death by apoptosis. All these results together suggest: a) the involvement of oxidative stress in the imbalance of AChE; and b) treatment with antioxidant agents may be a suitable strategy to protect cholinergic system alterations promoted by oxidative stress.

•

H₂O₂ impact on AChE structure from SH-SY5Y cells, acting as an allosteric effector.

•

H₂O₂ decreased AChE levels and changed AChE isoform profile from SH-SY5Y cells.

•

Oxidative stress could promote disturbances in cholinergic system.

Bioactive Fraction of Annona reticulata Bark (or) Ziziphus jujuba Root Bark along with Insulin Attenuates Painful Diabetic Neuropathy through Inhibiting NF-κB Inflammatory Cascade

The present study explains the neuroprotective ability of bioactive fractions of Annona reticulata bark (ARB) and Ziziphus jujuba root bark (ZJ) along with insulin against diabetic neuropathy. By using different solvents of increasing polarity ARB and ZJ were undergone for bioactive guided fractionation. The neuroprotective ability of the all the plant fractions were tested against H₂O₂ induced toxicity in SHSY5Y neuroblastoma cell lines and DRG neuronal cells. Among all the fractions tested, the methanol extract of ARB and ZJ (ARBME and ZJME) and its water fractions (ARBWF and ZJWF) exhibited significant neuroprotection against H₂O₂ induced toxicity in SHSY5Y cells and DRG neuronal cells. Further both the active fractions were tested against streptozotocin (55 mg/kg i.p.) induced diabetic neuropathy in male Wistar rats. Body weight changes, blood glucose levels and pain threshold through hot plate, tail immersion, cold plate and Randall-Sillitto methods were measured throughout the study at weekly interval. After completion of the drug treatment period, all the animals were sacrificed to measure the sciatic nerve lipid peroxidation, antioxidative enzyme levels (SOD, catalase, and GSH) and cytokine levels (IL-1β, IL-6, IL-10, TNF-α, iNOS, and NFκB) through ELISA and western blotting analysis. Results of this study explain that ARBME, ZJME, ARBWF, and ZJWF along with insulin potentially attenuate the thermal, mechanical hyperalgesia and cold allodynia in diabetic neuropathic rats, where insulin treatment alone failed to diminish the same. Reduction of sciatic nerve oxidative stress, NF-κB and iNOS mediated inflammatory cascade and normalization of abnormal cytokine release confirms the possible mechanism of action. The present study confirms the neuroprotective ability of ARB and ZJ against painful diabetic neuropathy through inhibiting oxidative stress and NF-κB inflammatory cascade.

Neuroprotective Effects of Bioavailable Polyphenol-Derived Metabolites against Oxidative Stress-Induced Cytotoxicity in Human Neuroblastoma SH-SY5Y Cells

Oxidative stress is involved in cell death in neurodegenerative diseases. Dietary polyphenols can exert health benefits, but their direct effects on neuronal cells are debatable because most phenolics are metabolized and do not reach the brain as they occur in the dietary sources. Herein, we evaluate the effects of a panel of bioavailable polyphenols and derived metabolites at physiologically relevant conditions against H₂O₂-induced apoptosis in human neuroblastoma SH-SY5Y cells. Among the 19 metabolites tested, 3,4-dihydroxyphenylpropionic acid, 3,4-dihydroxyphenylacetic acid, gallic acid, ellagic acid, and urolithins prevented neuronal apoptosis via attenuation of ROS levels, increased REDOX activity, and decreased oxidative stress-induced apoptosis by preventing the caspase-3 activation via the mitochondrial apoptotic pathway in SH-SY5Y cells. This suggests that dietary sources containing the polyphenol precursors of these molecules such as cocoa, berries, walnuts, and tea could be potential functional foods to reduce oxidative stress associated with the onset and progress of neurodegenerative diseases.

The Impact of CXCR4 Blockade on the Survival of Rat Brain Cortical Neurons

BACKGROUND

Chemokine receptor type 4 (CXCR4) plays a role in neuronal survival/cell repair and also contributes to the progression of cancer and neurodegenerative diseases. Chemokine ligand 12 (CXCL12) binds to CXCR4. In this study, we have investigated whether CXCR4 blockade by AMD3100 (a CXCR4 antagonist, member of bicyclam family) may affect neuronal survival in the absence of insult. Thus, we have measured the mitochondrial membrane potential (MMP), Bax and Bcl-2 protein translocation, and cytochrome c release in AMD3100-treated brain cortical neurons at 7 DIV (days in vitro).

METHODS

For this aim, AMD3100 (200 nM) was added to cortical neurons for 24 h, and several biomarkers like cell viability, reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) release, caspase-3/9 activity, proteins Bax and Bcl-2 translocation, and cytochrome c release were analyzed by immunoblot.

RESULTS

CXCR4 blockade by AMD3100 (200 nM, 24 h) induces mitochondrial hyperpolarization and increases caspase-3/9 hyperpolarization without affecting LDH release as compared to untreated controls. AMD3100 also increases cytochrome c release and promotes Bax translocation to the mitochondria, whereas it raises cytosolic Bcl-2 levels in brain cortical neurons.

CONCLUSION

CXCR4 blockade induces cellular death via intrinsic apoptosis in rat brain cortical neurons in absence of insult.

Phytanic Acid-Induced Neurotoxicological Manifestations and Apoptosis Ameliorated by Mitochondria-Mediated Actions of Melatonin

Phytanic acid, a saturated branched chain fatty acid and a major constituent of human diet, is predominantly found in dairy products, meat, and fish. It is a degradation product from the phytol side chain of chlorophyll. Degradation of PA is known to occur mainly in peroxisomes via α-oxidation and in mitochondria via β-oxidation. Due to its β-methyl group present at the 3-position of the carbon atoms, PA cannot be β-oxidized. Although alteration in the metabolism of PA may play an important role in neurodegeneration, the exact mechanism behind it remains to be evaluated. In this study, we have described the potential of PA to induce neurotoxicity as an in vitro model (neuronal cell line, SH-SY5Y cells). Cells were pretreated with melatonin (10 μM) for 1 h followed by with and without PA (100 μM) for 24 h. In the present study, our data has confirmed that PA markedly increased both intracellular reactive oxygen species and reactive nitrogen species levels. Our results have shown that PA treatment did not induce cell death by cleavage of caspase-3/PARP-1 mediated by mitochondria through intrinsic pathways; however, PA induced nitric oxide-dependent apoptosis in SH-SY5Y cells. Additionally, melatonin pretreatment reduced the cell death in SH-SY5Y cells. Melatonin also effectively exerted an antiapoptotic and anti-inflammatory action by regulating Bax, Bcl-2, p-NFκB, and iNOS expressions in SH-SY5Y cells. These results suggested that melatonin acted as an antioxidative and antiapoptotic agent by modulating ROS, apoptotic proteins, and inflammatory responses under BCFA-induced neurotoxic conditions. The protective effects of melatonin depend on direct scavenging activity of free radicals and indirect antioxidant effects. Further deciphering of the cellular and molecular mechanism associated with neuroprotection by melatonin is warranted in BCFA-induced neurotoxicity.

Neuroprotective Effects of Methyl 3,4-Dihydroxybenzoate against TBHP-Induced Oxidative Damage in SH-SY5Y Cells

This study investigated the neuroprotective effects of methyl 3,4-dihydroxybenzoate (MDHB) against t-butyl hydroperoxide (TBHP) induced oxidative damage in SH-SY5Y (human neuroblastoma cells) and the underlying mechanisms. SH-SY5Y were cultured in DMEM + 10% FBS for 24 h and pretreated with different concentrations of MDHB or N-acetyl-l-cysteine (NAC) for 4 h prior to the addition of 40 μM TBHP for 24 h. Cell viability was analyzed using the methylthiazolyltetrazolium (MTT) and lactate dehydrogenase (LDH) assays. An annexin V-FITC assay was used to detect cell apoptosis rates. The 2',7'-dichlorofluorescin diacetate (DCFH-DA) assay was used to determine intracellular ROS levels. The activities of antioxidative enzymes (GSH-Px and SOD) were measured using commercially available kits. The oxidative DNA damage marker 8-OHdG was detected using ELISA. Western blotting was used to determine the expression of Bcl-2, Bax, caspase 3, p-Akt and Akt proteins in treated SH-SY5Y cells. Our results showed that MDHB is an effective neuroprotective compound that can mitigate oxidative stress and inhibit apoptosis in SH-SY5Y cells.

Effects of Silicon vs. Hydroxytyrosol-Enriched Restructured Pork on Liver Oxidation Status of Aged Rats Fed High-Saturated/High-Cholesterol Diets

Background

Pork is an essential component of the diet that has been linked with major degenerative diseases and development of non-alcoholic steatohepatitis (NASH). Previous studies have. Previous studies have demonstrated the in vitro antioxidant activity of silicon (Si). Furthermore, when Si is added to restructured pork (RP) strongly counterbalances the negative effect of high-cholesterol-ingestion, acting as an active hypocholesterolemic and hypolipemic dietary ingredient in aged rats.

Objective

This study was designed to evaluate the effects of Si vs hydroxytyrosol (HxT) RP on liver antioxidant defense in aged rats fed cholesterol-enriched high saturated/high cholesterol diets as a NASH model.

Methods

Four diets were prepared: Control RP diet (C) with non-added cholesterol; Cholesterol-enriched high-saturated/high-cholesterol control RP diet (CHOL-C) with added cholesterol and cholic acid; Si- or HxT-RP cholesterol-enriched high-saturated/high-cholesterol diets (CHOL-Si and CHOL-HxT). Groups of six male Wistar rats (1-yr old) were fed these modified diets for eight weeks. Total cholesterol, hepatosomatic index, liver Nrf2 and antioxidant (CAT, SOD, GSH, GSSG, GR, GPx) markers were determined.

Results

Both CHOL-Si and CHOL-HxT diets enhanced the liver antioxidant status, reduced hepatosomatic index and increased SOD actvity. Hydrogen peroxide removal seemed to be involved, explaining that the value of redox index was even lower than C without changing the CAT activity. CHOL-Si results were quite better than CHOL-HxT in most measured parameters.

Conclusions

Our study suggests that Si incorporated into RP matrix was able to counterbalance, more efficiently than HxT, the deleterious effect of consuming a high-saturated/high-cholesterol diet, by improving the liver antioxidant defenses in the context of NASH.

Silicon-Enriched Restructured Pork Affects the Lipoprotein Profile, VLDL Oxidation, and LDL Receptor Gene Expression in Aged Rats Fed an Atherogenic Diet

BACKGROUND

Research has shown that silicon can play an important role in protecting against degenerative diseases. Restructuring pork by partially disassembling meat permits the incorporation of active components with potential functional effects. However, there has been no research to date on the impact that silicon, as a functional ingredient in restructured pork (RP), has on lipoprotein composition, metabolism, and oxidation.

OBJECTIVE

This study was designed to evaluate the effect of silicon-enriched RP on lipemia, lipoprotein profile, and oxidation markers of aged rats fed high-fat, high-energy, cholesterol-enriched diets.

METHODS

RP samples similar to commercial sausages (16% protein and 22% fat, wt:wt) were prepared by mixing lean pork and lard alone or with silicon (1.3 g Si/kg fresh matter) under controlled conditions and then freeze-dried. Saturated fat-rich diets were designed by mixing 78.3% purified diet with 21.7% freeze-dried RP. Three groups composed of 8 aged male Wistar rats (1 y old) were fed for 8 wk a control RP (C) diet, a cholesterol-enriched RP (Chol-C) diet [C diet enriched with 1.26% cholesterol plus 0.25% cholic acid, or a cholesterol and silicon-enriched RP (Chol-Si) diet (same as the Chol-C diet but containing silicon)]. Plasma lipid concentrations, lipoprotein profile, the degree of VLDL oxidation, and LDL receptor gene (Ldlr) expression were tested.

RESULTS

Compared with the C diet, the Chol-C diet did not modify food intake or body weight but significantly increased (P < 0.05) plasma cholesterol (32%) and total lipids (19%), VLDL and intermediate density lipoprotein + LDL cholesterol (both >600%), total lipids and proteins (both >300%), and the degree of VLDL oxidation [conjugated dienes >250%; thiobarbituric acid-reactive substance (TBARS), 900%] and reduced Ldlr expression (64%) and liver arylesterase activity (54%). The Chol-Si diet partially normalized changes induced by the Chol-C diet. Compared with the Chol-C group, Chol-Si rats had lower VLDL compound concentrations (P < 0.001; e.g., 75% less VLDL cholesterol) and VLDL oxidation (65% less conjugated dienes and 85% less TBARS) but greater Ldlr expression (200%).

CONCLUSIONS

Silicon added to RP strongly counterbalanced the negative effect of high-cholesterol-ingestion, functioning as an active hypocholesterolemic, hypolipemic, and antioxidative dietary ingredient in aged rats.

Silicon as neuroprotector or neurotoxic in the human neuroblastoma SH-SY5Y cell line

Silicon (Si) is a trace element that has been considered to be an environmental contaminant for many years, although different studies have recently reported it is an essential element for living cells. The present study tested the ability of different concentrations of Si G57™ to induce neuroprotection or neurotoxicity over 24 h in the SH-SY5Y human neuroblastoma cell line. Cell viability, cellular proliferation, LDH release, ROS, antioxidant capacity, TBARS, caspase-3, -8 and -9, DNA fragmentation, and TNF-α levels were evaluated. Low Si doses (50-250 ng mL(-1)) increased the cell viability and reduced caspase-3 and -8 activities and TNF-α level. The increase in cell viability was independent of any proliferative effect as there was no variation in cyclin E and PCNA levels. At higher concentrations, Si increased caspase-3, as well as TBARS, LDH, DNA fragmentation, and TNF-α releases. Altogether, these results suggest that Si could act either as a neuroprotector or a neurotoxic agent depending on the concentration tested. This study emphasizes the importance of developing new neuroprotective therapies based on low Si doses.

Neuroprotective activity and cytotoxic potential of two Parmeliaceae lichens: Identification of active compounds

BACKGROUND

Lichens are symbiotic organisms capable of producing unique secondary metabolites, whose pharmacological activities are attracting much interest.

PURPOSE

The present study aimed to investigate the in vitro neuroprotective effects and anticancer potential of methanol extracts of two Parmeliaceae lichens: Cetraria islandica and Vulpicida canadensis. The chemical composition of the two lichens was also determined.

METHODS

Neuroprotective activity was studied with respect to the antioxidant properties of the extracts; radical scavenging tests (ORAC and DPPH assays) were performed and oxidative stress markers (intracellular ROS production, caspase-3 activity, MDA and glutathione levels) were assessed in a hydrogen peroxide-induced oxidative stress model in astrocytes. Cytotoxic activity was tested against human HepG2 (hepatocellular carcinoma) and MCF-7 (breast adenocarcinoma) cell lines.

RESULTS

Cell viability studies identified a single concentration for each extract that was subsequently used to measure oxidative stress markers. Lichen extracts were able to reverse the oxidative damage caused by hydrogen peroxide, thus promoting astrocyte survival. Both lichen extracts also had anticancer activity in the cell lines, with IC50 values of 19.51-181.05 µg/ml. The extracts had a high total phenolic content, and the main constituents identified by HPLC were fumarprotocetraric acid in Cetraria islandica, and usnic, pinastric and vulpinic acids in Vulpicida canadensis. The biological activities of the lichen extracts can be attributed to these secondary metabolites.

CONCLUSION

The lichen species studied are promising sources of natural compounds with neuroprotective activity and cytotoxic potential, and warrant further research.

Neuroprotective effects of Liriope platyphylla extract against hydrogen peroxide-induced cytotoxicity in human neuroblastoma SH-SY5Y cells

Background

Oxidative stress is involved in neuronal cell death and mitochondrial dysfunction in neurodegenerative diseases. Liriope platyphylla (LP) has been suggested to have anti-inflammation, anti-bacterial, and anti-cancer effects. However, whether LP exerts neuroprotective effects on neuronal cells is unknown.

Methods

The present study was performed to investigate the neuroprotective effects of LP extract (LPE) against hydrogen peroxide (H₂O₂)-induced injury in human neuroblastoma cells SH-SY5Y. To test neuroprotective effects of LPE, we performed cell viability assay, flow cytometry analysis and western blot analysis. In addition, mitochondrial membrane potential (MMP) and oxidative stress were performed to evaluate the anti-apoptotic and anti-oxidant effects.

Results

LPE pretreatment conferred significant protection against the H₂O₂-induced decrease of SH-SY5Y cell viability. H₂O₂-induced increases of intracellular oxidative stress and mitochondrial dysfunction were attenuated by LPE pretreatment. Therefore, LPE pretreatment prevented SH-SY5Y cell injury. Treatment with H₂O₂ significantly induced poly(ADP ribose) polymerase (PARP) and caspase-3 cleavage, which was blocked by LPE. We found that p38 activation was involved in the neuroprotective effects of LPE.

Conclusions

Current findings suggest that LPE exerts neuroprotective effects against H₂O₂-induced apoptotic cell death by modulating p38 activation in SH-SY5Y cells. Therefore, LPE has potential anti-apoptotic effects that may be neuroprotective in neurodegenerative diseases and aging-related dementia.