H2O2-induced Stress Research Articles

Antioxidant, Apoptotic, and Wound Healing Effects of Xantolis Cambodiana Extracts in Normal Human Dermal Fibroblasts.

Xantolis cambodiana has demonstrated significant antioxidant properties; however, the mechanisms underlying its protective effects against oxidative stress in cellular systems remain unexplored. This work investigated the efficacy of methanolic extracts in exhibiting oxidative damage and examined their mechanisms. The methanolic extract had a high phenolic content (116.89±29.01 mg GAE/g FW) and exhibited scavenging of 2,2-diphenyl-1-picrylhydrazyl radicals with an IC50 value of 42.35±9.20 μg/ml. In addition, it had the highest antioxidant activity based on ferric-reducing antioxidant power (467.45±50.74 mg AA/100 g). Normal human dermal fibroblast (NHDF) cells were pretreated with the methanolic extract in a hydrogen peroxide (H2O2; 500 mM)-induced oxidative stress model, which resulted in a significant decrease in apoptosis and autophagy. Not only did the methanolic extract reduce mitochondrial membrane potential, it also stimulated NHDF cell migration and reduced reactive oxygen species production through mitochondrial dysfunction in the H2O2-induced stress model. These findings suggested that the methanolic extract (25 μg/ml) attenuated H2O2-induced oxidative stress in NHDF cells, significantly reducing apoptosis, autophagy, and mitochondrial dysfunction. Thus, this extract has the potential to support the wound healing process due to its antioxidant activity.

The Influence of Cichorium Endivia and Urtica Dioica Extracts Against H2O2-Induced Stress in SH-SY5Y Cells

Aim: In neurodegenerative diseases, increased production of hydrogen peroxide (H2O2) causes oxidative stress in neurons, and when the damage is severe, it is irreversible and apoptosis is induced. In recent years, phytochemicals that exhibit neuroprotective and antioxidant properties to protect neurons from oxidative stress have gained importance. Therefore, herbal extracts with high antioxidant capacity and anti-apoptotic properties may provide a protective strategy against H2O2-induction. This study aims to examine the influence of Cichorium endivia liquid extract (CEE) and Urtica dioica liquid extract (UDE) against H2O2-induction on SH-SY5Y cells in vitro. Method: For this purpose, cells were treated with the extracts and then exposed to H2O2. The neuroprotective effect and cell viability of these extracts were evaluated by XTT method. Antioxidant activity was determined by the CUPRAC method. Finally, the apoptotic cell death and reactive oxygen species (ROS) levels were examined with DAPI and DCFH-DA, respectively. Results: The results obtained showed that CEE and UDE have an influence on neuroprotection, anti-apoptotic, and antioxidant effects by reducing H2O2-induced toxicity, apoptotic cell death, and ROS levels. Conclusion: H2O2 causes neurotoxicity in neurons through oxidative damage. To prevent this, traditional plant extracts with high antioxidant activity can provide a neuroprotective strategy. As a consequence, it was shown in an in vitro model that these herbal extracts could be a neuroprotective effect.

Cardioprotective effect of Robinin ameliorates Endoplasmic Reticulum Stress and Apoptosis in H9c2 cells.

Robinin is one of the glycosyloxyflavones that has been less explored for its therapeutic application, especially in the field of CVD. Herein, we explored the cardioprotective efficacy of Robinin by using H2O2 and Doxorubicin (DOX) - treated H9c2 cells as an in vitro model. H2O2 and DOX treatment resulted in severe cellular damage to the cardiomyocytes, which was followed by apoptosis. Apoptosis and nuclear morphology were analysed through Hoechst 33342 and AO/EB staining. qPCR was employed to detect the expression of apoptosis as well as ERS-related markers. Reactive oxygen species (ROS) generation was observed using DCFH-DA staining and FACS analysis. Signaling pathways involved were analysed using Western blot. Robinin pre-treatment considerably decreased the apoptotic rate by boosting the endogenous anti-oxidative activity and lowering the activity of Malonaldehyde and Lactate dehydrogenase enzyme. Robinin also inhibited the generation of ROS. Robinin reduced the expression of ERS-associated genes and proteins, thereby decreasing apoptosis-related proteins. Upon comparing the cardioprotective effect of Robinin with a known cardioprotective agent Dexrazoxane (DEX) it was revealed that DEX has more cardioprotective effect against DOX than H2O2-induced stress, while Robinin showed a significant protective effect against both H2O2 and DOX induced stress.

Comparison of the protective effects of chitosan oligosaccharides and chitin oligosaccharide on apoptosis, inflammation and oxidative stress.

Chitin degradation products, especially chitosan oligosaccharides (COSs), are highly valued in various industrial fields, such as food, medicine, cosmetics and agriculture, for their rich resources and high cost-effectiveness. However, little is known about the impact of acetylation on COS cellular bioactivity. The present study aimed to compare the differential effects of COS and highly N-acetylated COS (NACOS), known as chitin oligosaccharide, on H2O2-induced cell stress. MTT assay showed that pretreatment with NACOS and COS markedly inhibited H2O2-induced RAW264.7 cell death in a concentration-dependent manner. Flow cytometry indicated that NACOS and COS exerted an anti-apoptosis effect on H2O2-induced oxidative damage in RAW264.7 cells. NACOS and COS treatment ameliorated H2O2-induced RAW264.7 cell cycle arrest. Western blotting revealed that the anti-oxidation effects of NACOS and COS were mediated by suppressing expression of proteins involved in H2O2-induced apoptosis, including Bax, Bcl-2 and cleaved PARP. Furthermore, the antagonist effects of NACOS were greater than those of COS, suggesting that acetylation was essential for the protective effects of COS.

Nanovesicular Mediation of the Gut-Brain Axis by Probiotics: Insights into Irritable Bowel Syndrome.

Dysbiosis, influenced by poor diet or stress, is associated with various systemic diseases. Probiotic supplements are recognized for stabilizing gut microbiota and alleviating gastrointestinal issues, like irritable bowel syndrome (IBS). This study focused on the tryptophan pathways, which are important for the regulation of serotonin levels, and on host physiology and behavior regulation. Nanovesicles were isolated from the plasma of subjects with chronic diarrhea, both before and after 60 days of consuming a probiotic mix (Acronelle®, Bromatech S.r.l., Milan, Italy). These nanovesicles were assessed for the presence of Tryptophan 2,3-dioxygenase 2 (TDO 2). Furthermore, the probiotics mix, in combination with H2O2, was used to treat HT29 cells to explore its cytoprotective and anti-stress effect. In vivo, levels of TDO 2 in nanovesicles were enhanced in the blood after probiotic treatment, suggesting a role in the gut-brain axis. In the in vitro model, a typical H2O2-induced stress effect occurred, which the probiotics mix was able to recover, showing a cytoprotective effect. The probiotics mix treatment significantly reduced the heat shock protein 60 kDa levels and was able to preserve intestinal integrity and barrier function by restoring the expression and redistribution of tight junction proteins. Moreover, the probiotics mix increased the expression of TDO 2 and serotonin receptors. This study provides evidence for the gut-brain axis mediation by nanovesicles, influencing central nervous system function.

Pharmacological effects of methysticin and L-sulforaphane through the Nrf2/ARE signaling pathway in MLO-Y4 osteocytes: in vitro study

BackgroundOxidative stress plays a crucial role in the pathogenesis of many skeletal diseases by inducing osteocyte death. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of various antioxidant gene expressions through antioxidant response element (ARE) against cellular oxidative stress and can be induced by various stimulants, including the phytochemicals methysticin (MET) and L-sulforaphane (SFN). This study aimed to establish an osteocyte in vitro model to investigate the pharmacological effects of MET and SFN on the Nrf2/ARE pathway. MethodsMLO-Y4 murine osteocytes and the stably transduced MLO-Y4-SIN-lenti-ARE reporter gene cell line were used. MET and SFN were used as Nrf2 inducers. The cytotoxicity of MET, SFN, and hydrogen peroxide (H2O2) was evaluated using the CytoTox-Glo™ Assay. Time- and dose-dependent ARE induction was examined by Monoluciferase Assay. The mRNA and protein expressions of Nrf2 target markers, such as heme-oxygenase 1 (Ho-1), NADPH quinone dehydrogenase 1 (Nqo1), and thioredoxin reductase 1 (Txnrd1), were detected by RT-qPCR, Western Blot, and immunofluorescence staining, respectively. Osteogenesis markers, osteopontin, and osteocalcin were compared with and without treatment by immunofluorescence staining. ResultsThe experimental data showed that MET and SFN induced ARE activity in a time- and dose-dependent manner and increased the mRNA and protein expression of antioxidant markers compared to vehicle-treated controls. The protein expression of osteopontin and osteocalcin in the samples treated with SFN were significantly higher than without treatment, and the number of cell death treated with SFN was significantly lower than without treatment under H2O2-induced stress conditions. ConclusionsNrf2 inducers MET and SFN increased the mRNA expression of antioxidant genes through the Nrf2/ARE pathway in osteocytes. Notably, SFN increased the protein expression of osteocyte-associated osteogenic markers and suppressed cell death under H2O2-induced stress condition. Thus, Nrf2 stimulators can exert stress-relieving and osteogenic effects on osteocytes.

Toward Enhanced Antioxidant and Protective Potential: Conjugation of Corn Cob Xylan with Gallic Acid as a Novel Approach.

Maize ranks as the second most widely produced crop globally, yielding approximately 1.2 billion tons, with corn cob being its primary byproduct, constituting 18 kg per 100 kg of corn. Agricultural corn production generates bioactive polysaccharide-rich byproducts, including xylan (Xyl). In this study, we used the redox method to modify corn cob xylan with gallic acid, aiming to enhance its antioxidant and protective capacity against oxidative stress. The conjugation process resulted in a new molecule termed conjugated xylan-gallic acid (Xyl-GA), exhibiting notable improvements in various antioxidant parameters, including total antioxidant capacity (1.4-fold increase), reducing power (1.2-fold increase), hydroxyl radical scavenging (1.6-fold increase), and cupric chelation (27.5-fold increase) when compared with unmodified Xyl. At a concentration of 1 mg/mL, Xyl-GA demonstrated no cytotoxicity, significantly increased fibroblast cell viability (approximately 80%), and effectively mitigated intracellular ROS levels (reduced by 100%) following oxidative damage induced by H2O2. Furthermore, Xyl-GA exhibited non-toxicity toward zebrafish embryos, offered protection against H2O2-induced stress, and reduced the rate of cells undergoing apoptosis resulting from H2O2 exposure. In conclusion, our findings suggest that Xyl-GA possesses potential therapeutic value in addressing oxidative stress-related disturbances. Further investigations are warranted to elucidate the molecular structure of this novel compound and establish correlations with its pharmacological activities.

The interplay of low H2O2 doses, lytic cyanophage, and Microcystis aeruginosa: Implications for cyanobacterial bloom control and microcystin production/release

Low H2O2 doses can suppress cyanobacterial blooms without damaging non-target species but enable undesirable regrowth. Besides, the role of cyanophage in preventing regrowth after low H2O2 exposure remains unclear. Applying phages to cyanobacteria pre-exposed to low H2O2 in early growth stages may improve host removal and reduce microcystin (MC) production/release. Lytic cyanophage MDM-1 with a 172 PFU/cell burst size, 2-day short latent period against MCs-producing Microcystis, shows high H2O2 stability. Low H2O2 (1 to 2.5 mg/L) doses significantly (p < 0.05) inhibited Microcystis aeruginosa growth rate, biofilm and MCs concentration reduction in a dose-dependent manner but regrowth occurred at all concentrations. Phage treatment eliminated cells without H2O2 pretreatment within 3 days and reduced MC production. H2O2-pretreated M. aeruginosa cells altered the phage dynamics, affecting adsorption, latency, production, and cell lysis in response to H2O2-induced oxidative stress. At 1.5 mg H2O2/L pretreatment, cells were eliminated with reduced MC production, like untreated cells. H2O2 pretreatment with 2.0 and 2.5 mg/L resulted in an extension of the phage absorption phase and the latent period. This was accompanied by a reduction in lysis efficacy, attributed to the increased ROS production. At 2.5 mg H2O2/L, 17.10 % of phages remain un-adsorbed, with cell lysis rate dropped from 0.89 d−1 to 0.26 d−1 compared to the untreated control. The highest phage titer (70 %) was obtained with 1.5 mg/H2O2 pretreated cells. This study emphasizes that low-dose H2O2 eliminates Microcystis but severely affects phage lysis and MCs release depending on H2O2-induced ROS levels. It is a crucial consideration when using phages to control cyanobacterial blooms with H2O2-induced stress.

Puerarin attenuates myocardial ischemic injury and endoplasmic reticulum stress by upregulating the Mzb1 signal pathway.

This study investigated the role of Mzb1 in puerarin protection against heart injury and dysfunction in acute myocardial infarction (AMI) mice. C57BL/6 mice were pretreated with and without puerarin at doses of 50mg/kg and 100mg/kg for 14days before establishing the AMI model. An AMI model was induced by ligating the left descending anterior coronary artery, and AC16 cardiomyocytes were treated with H2O2 in vitro. Echocardiography was performed to measure cardiac function. DHE staining, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase assay, and DCFH-DA oxidative fluorescence staining were used to determine reactive oxygen species (ROS) production in vivo and in vitro. Bioinformatics analysis was used to predict potential upstream transcription factors of Mzb1. Puerarin dose-dependently reduced myocardial infarction area and injury, accompanied by the improvement of cardiac function in AMI mice. AMI mice manifested an increase in myocardial oxidative stress, endoplasmic reticulum (ER) stress, apoptosis, and mitochondrial biogenesis dysfunction, which were inhibited by pretreatment with puerarin. Puerarin also prevented Mzb1 downregulation in the hearts of AMI mice or H2O2-treated AC16 cells. Consistent with the in vivo findings, puerarin inhibited H2O2-induced cardiomyocyte apoptosis, ER stress, and mitochondrial dysfunction, which were attenuated by siRNA Mzb1. Furthermore, the JASPAR website predicted that KLF4 may be a transcription factor for Mzb1. The expression of KLF4 was partially reversed by puerarin in the cardiomyocyte injury model, and KLF4 inhibitor (kenpaullone) inhibited Mzb1 expression and affected its function. These results suggest that puerarin can protect against cardiac injury by attenuating oxidative stress and endoplasmic reticulum stress through upregulating the KLF4/Mzb1 pathway and that puerarin may expand our armamentarium for the prevention and treatment of ischemic heart diseases.

Metformin enhances METTL14-Mediated m6A methylation to alleviate NIT-1 cells apoptosis induced by hydrogen peroxide

Injuries to pancreatic β-cells are intricately linked to the onset of diabetes mellitus (DM). Metformin (Met), one of the most widely prescribed medications for diabetes and metabolic disorders, has been extensively studied for its antioxidant, anti-aging, anti-glycation, and hepatoprotective activities. N6-methyladenosine (m6A) plays a crucial role in the regulation of β-cell growth and development, and its dysregulation is associated with metabolic disorders. This study aimed to elucidate the mechanistic basis of m6A involvement in the protective effects of Met against oxidative damage in pancreatic β-cells. Hydrogen peroxide (H2O2) was employed to induce β-cell damage. Remarkably, Met treatment effectively increased methylation levels and the expression of the methyltransferase METTL14, subsequently reducing H2O2-induced apoptosis. Knocking down METTL14 expression using siRNA significantly compromised cell viability. Conversely, targeted overexpression of METTL14 specifically in β-cells substantially enhanced their capacity to withstand H2O2-induced stress. Molecular evidence suggests that the anti-apoptotic properties of Met may be mediated through Bcl-xL and Bim proteins. In conclusion, our findings indicate that Met induces METTL14-mediated alterations in m6A methylation levels, thereby shielding β-cells from apoptosis and oxidative damage induced by oxidative stress.

Angiotensin 1-7 Exerts Antioxidant Effects, Suppresses Mammalian Target of Rapamycin (mTOR) Signaling, and Inhibits Apoptosis in Renal Proximal Tubular Cells

Oxidative stress is one of the crucial pathogenic factors involved in the progression of renal injury. Angiotensin (ANG) 1-7, a bioactive heptapeptide of the renin-angiotensin-aldosterone system is known to exert antioxidant and nephroprotective effects. However, the cellular mechanism involved in the beneficial effect of ANG 1-7 is not clear. Here, we assessed ANG 1-7’s effect on H2O2-mediated oxidative damage in the human proximal tubular (HK2) cells and the underlying mechanisms. HK2 cells were incubated with H2O2 (500µM, 4h) pre-treated with and without ANG 1-7 (100nM, 24h), and reactive oxygen species (ROS) generation, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, apoptosis and mammalian target of rapamycin (mTOR) signaling were determined. H2O2 induced an increase in oxidative and ER stress together with loss of mitochondrial membrane potential, decreased ATP levels, and induced apoptosis in HK2 cells. Moreover, H2O2 treatment resulted in the activation of mTOR complexes (mTORC1 and mTORC2) in these cells. ANG 1-7 significantly attenuated H2O2-induced ROS generation, ER stress and apoptosis, and also improved mitochondrial function. Additionally, pre-treatment of ANG 1-7 inhibited the H2O2-mediated mTOR activation. These effects of ANG 1-7 were blocked by co-treatment with the Mas receptor (MasR) inhibitor, A779. Furthermore, transfection of HK2 cells with Mas receptor siRNA also abolished the inhibitory effect of ANG 1-7 on mTOR activities. In conclusion, ANG 1-7 via MasR mitigates oxidative stress, suppresses mTOR signaling, and protects HK2 cells from ER stress, mitochondrial dysfunction, and apoptosis, suggesting ANG 1-7-MasR renoprotective effects.

Integrating eco-friendly approaches to produce protein extracts and hydrolysates with antioxidant properties from Microchloropsis gaditana

In recent years, microalgae have emerged as sustainable alternatives to conventional animal-based proteins and powerful sources of bioactive peptides. This study aimed to develop an eco-friendly workflow using ultrasounds and green solvents to extract proteins from Microchloropsis gaditana and enzymatically produce antioxidant hydrolysates. The ultrasound method yielded comparable protein amounts to the traditional approach, reducing extraction time (1 vs. 5 h) and using a greener solvent (water vs. 5 % NaOH). The enzymatic solutions Flavourzyme® and Alcalase® successfully produced protein hydrolysates with up to 70 % hydrolysis, depending on the hydrolysis time. Regarding biological activity, the protein extract and certain hydrolysates (Flavourzyme® after 2 h and Alcalase® after 8 h of hydrolysis time) showed promising antioxidant effects, as these substances significantly suppressed the intracellular reactive oxygen species (ROS) levels in HCT 116 cells under H2O2-induced stress. The proteomic analysis uncovered up to 288 proteins, in which antioxidant activity-related proteins and the protein Histone H2A were identified, suggesting a potential correlation with the observed biological activity. Thus, this multidisciplinary approach sheds light on the green production of protein extracts and hydrolysates from microalgae and presents an integrated process for producing antioxidant extracts, holding significant promise as potential ingredients for functional foods and nutraceuticals.

Abstract 17153: Mitochondrial Cx43 and Gja1-20k Contribute to Sex-Specific Differences of Mitochondrial Response in Septic Cardiomyopathy

Introduction: Cardiac dysfunction contributes to morbidity and mortality of severe sepsis. Preserving mitochondrial (mito) activity is key to maintaining cardiac function. While epidemiological studies consistently report that male sex is an important risk factor for severe sepsis, it is unknown if male heart mito are susceptible to septic injury. We have shown that male cardiomyocyte mito were more vulnerable to TNFα- or H 2 O 2 -induced stress than females. We have also demonstrated that mito connexin 43 (Cx43 or Gja1) and its smaller isoform - Gja1-20k are implicated in sex-related heart response following myocardial ischemia. Hypothesis : In this study, we hypothesize that during sepsis, female (F) hearts exhibit preserved mito Cx43 and Gja1-20k to confer mitochondrial protection, thus improving cardiac function compared to male (M) myocardium. Methods: Age-matched adult M &amp; F C57BL/6 mice received LPS (7.5 mg/kg BW, i.p.) or PBS (n &gt; 6 mice/group). Cardiac function was detected 20h post LPS by 2D echocardiography. Cx43, Gja1-20k, OXPHOS, &amp; PGC-1 were evaluated in M &amp; F mouse heart mito 24h after LPS by Western Blot (n&gt;3 hearts/group). Mito Cx43 was also detected by Immuno-electron microscopy (EM). Mito membrane potential (ΔΨm) was analyzed in cardiomyocytes (from adult M &amp; F mice, n&gt;3 hearts/group) +/- 1h LPS (1 μg/ml) using JC1 fluorescent probe. Mito respiration capacity was further assessed in H9c2 cells transfected with Gja1 siRNA upon LPS exposure by Seahorse XF Mito Stress test. Results: Decreased cardiac function was observed in M mice after LPS injection, but not in F. Higher mito levels of Cx43, Gja1-20k, OXPHOS, &amp; PGC1 were noticed in F mouse hearts compared to M after LPS. Despite no difference in total Cx43 particles between M &amp; F hearts by EM, more gold Cx43 particles were observed in F heart mito compared to M mito following LPS. LPS reduced ΔΨm in M cardiomyocytes, but not in F. Cx43 knockdown decreased mito maximal respiration capacity &amp; ATP production in H9c2 cells with LPS stress. Conclusions: The mitochondria-derived protective mechanism is preserved in F mice, leading to better cardiac function than M mice following LPS-induced sepsis. F cardiac mito are more resistant to LPS challenge than M mito, partially due to preserved mito Cx43 and/or Gja1-20k.

Selenomethionine Attenuated H2O2-Induced Oxidative Stress and Apoptosis by Nrf2 in Chicken Liver Cells.

Earlier studies have shown that selenomethionine (SM) supplements in broiler breeders had higher deposition in eggs, further reduced the mortality of chicken embryos, and exerted a stronger antioxidant ability in offspring than sodium selenite (SS). Since previous studies also confirmed that Se deposition in eggs was positively correlated with maternal supplementation, this study aimed to directly investigate the antioxidant activities and underlying mechanisms of SS and SM on the chicken hepatocellular carcinoma cell line (LMH). The cytotoxicity results showed that the safe concentration of SM was up to 1000 ng/mL, while SS was 100 ng/mL. In Se treatments, both SS and SM significantly elevated mRNA stability and the protein synthesis rate of glutathione peroxidase (GPx) and thioredoxin reductase (TrxR), two Se-containing antioxidant enzymes. Furthermore, SM exerted protective effects in the H2O2-induced oxidant stress model by reducing free radicals (including ROS, MDA, and NO) and elevating the activities of antioxidative enzymes, which performed better than SS. Furthermore, the results showed that cotreatment with SM significantly induced apoptosis induced by H2O2 on elevating the content of Bcl-2 and decreasing caspase-3. Moreover, investigations of the mechanism revealed that SM might exert antioxidant effects on H2O2-induced LMHs by activating the Nrf2 pathway and enhancing the activities of major antioxidant selenoenzymes downstream. These findings provide evidence for the effectiveness of SM on ameliorating H2O2-induced oxidative impairment and suggest SM has the potential to be used in the prevention or adjuvant treatment of oxidative-related impairment in poultry feeds.

Influence of microbial fermentation on the antioxidant activity of phenolic substances in Saccharomyces cerevisiae.

Using in vitro assay and eukaryotic cell model of Saccharomyces cerevisiae, we investigated the impact of microbial fermentation on the antioxidant activity of phenolic substances. Caffeic acid phenethyl ester (CAPE) and mangiferin were fermented by lactic acid bacteria (LAB), and the antioxidant activity of the fermented products was compared to that of the pure substances. This comparison was assessed using high-performance liquid chromatography (HPLC), in vitro by 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and in vivo in yeast cells. The wild-type strain (BY4741) and its isogenic mutants in glutathione (Δgsh1), catalase (Δctt1), and superoxide dismutase (Δsod1) were treated with CAPE and mangiferin, fermented or not, and exposed to hydrogen peroxide (H2O2)-induced stress. The antioxidant activity was evaluated by cellular viability, intracellular oxidation, and lipid peroxidation. We expected that fermentation would change the antioxidant activity of phenolic substances. While HPLC analysis revealed changes in the composition of fermented products, significant alterations in antioxidant activity were only observed when using mutant strains. The fermentation of mangiferin increased dependency on GSH compared to the respective pure phenolic substance to resolve H2O2-induced stress. Additionally, CAPE appeared to act as a preconditioning agent, enhancing antioxidant responses, and promoting increased tolerance to H2O2 stress, and this mechanism was maintained after fermentation. This study highlights that fermentation impacts the enzymatic mechanism of oxidative stress resolution, even though differences could not be observed in in vitro assays or in the wild-type strain.

Polysaccharides Extracted from Dendrobium officinale Grown in Different Environments Elicit Varying Health Benefits in Caenorhabditis elegans.

Dendrobium officinale is one of the most widely used medicinal herbs, especially in Asia. In recent times, the polysaccharide content of D. officinale has garnered attention due to the numerous reports of its medicinal properties, such as anticancer, antioxidant, anti-diabetic, hepatoprotective, neuroprotective, and anti-aging activities. However, few reports of its anti-aging potential are available. Due to high demand, the wild D. officinale is scarce; hence, alternative cultivation methods are being employed. In this study, we used the Caenorhabditis elegans model to investigate the anti-aging potential of polysaccharides extracted from D. officinale (DOP) grown in three different environments; tree (TR), greenhouse (GH), and rock (RK). Our findings showed that at 1000 µg/mL, GH-DOP optimally extended the mean lifespan by 14% and the maximum lifespan by 25% (p < 0.0001). TR-DOP and RK-DOP did not extend their lifespan at any of the concentrations tested. We further showed that 2000 µg/mL TR-DOP, GH-DOP, or RK-DOP all enhanced resistance to H2O2-induced stress (p > 0.05, p < 0.01, and p < 0.01, respectively). In contrast, only RK-DOP exhibited resistance (p < 0.01) to thermal stress. Overall, DOP from the three sources all increased HSP-4::GFP levels, indicating a boost in the ability of the worms to respond to ER-related stress. Similarly, DOP from all three sources decreased α-synuclein aggregation; however, only GH-DOP delayed β-amyloid-induced paralysis (p < 0.0001). Our findings provide useful information on the health benefits of DOP and also provide clues on the best practices for cultivating D. officinale for maximum medicinal applications.

Lutein loaded double-layered polymer nanocarrier modulate H2O2 and CoCl2 induced oxidative and hypoxia damage and angiogenic markers in ARPE-19 cells

Lutein plays a crucial role in the protection of retina by diminishing oxidative stress in diabetic retinopathy (DR). However, its poor aqueous solubility, chemical instability and low bioavailability edge its application. Also, beneficial effects of lutein supplementation and lower lutein levels in the serum and retina of DR patients created an interest in nanopreparation. Hence, lutein-loaded chitosan‑sodium alginate nanocarrier comprising oleic acid core (LNCs) was developed and examined its protective effect on hyperglycemia-mediated changes in oxidative stress and angiogenesis in ARPE-19 cells. Results showed that the LNCs have smaller size and a smooth spherical morphology and did not affect the ARPE-19 cell viability (up to 20 μM) and showed higher cellular uptake in both normal and H2O2-induced stress conditions. LNCs pre-treatment suppressed the H2O2-induced oxidative stress and CoCl2-induced hypoxia-mediated elevation of intracellular reactive oxygen species, protein carbonyl and malondialdehyde levels by restoring antioxidant enzymes in ARPE-19 cells. Further, LNCs protected H2O2-mediated down-regulation of Nrf2 and its downstream antioxidant enzymes. LNCs also restored the H2O2-altered angiogenic (Vascular endothelial growth factor (VEGF), X-box binding protein 1 (XBP-1) and Hypoxia-inducible factor 1-alpha (HIF-1α)), endoplasmic reticulum stress (activating transcription factor-4 (ATF4)) and tight junction (Zona occludens 1 (ZO-1)) markers. To conclude, we could successfully develop biodegradable LNCs to improve the cellular uptake of lutein to treat DR by curtailing oxidative stress in retina.

Anti-Cholinesterase and Anti-α-Amylase Activities and Neuroprotective Effects of Carvacrol and p-Cymene and Their Effects on Hydrogen Peroxide Induced Stress in SH-SY5Y Cells.

Several researchers have demonstrated the health and pharmacological properties of carvacrol and p-cymene, monoterpenes of aromatic plants. This study investigated these compounds' possible anti-cholinesterase, anti-α-amylase, and neuroprotective effects. We evaluated the anti-acetylcholinesterase and anti-α-amylase activities at different concentrations of the compounds. The maximum non-toxic dose of carvacrol and p-cymene against SH-SY5Y neuroblastoma cells was determined using an MTT assay. The neuroprotective effects of the compounds were evaluated on H2O2-induced stress in SH-SY5Y cells, studying the expression of caspase-3 using Western blotting assays. Carvacrol showed inhibitory activities against acetylcholinesterase (IC50 = 3.8 µg/mL) and butyrylcholinesterase (IC50 = 32.7 µg/mL). Instead, the anti-α-amylase activity of carvacrol resulted in an IC50 value of 171.2 μg/mL After a pre-treatment with the maximum non-toxic dose of carvacrol and p-cymene, the expression of caspase-3 was reduced compared to cells treated with H2O2 alone. Carvacrol and p-cymene showed in vitro anti-enzymatic properties, and may act as neuroprotective agents against oxidative stress. Further studies are necessary to elucidate their possible use as coadjutants in preventing and treating AD in diabetic patients.

PAMAM dendrimers of generation 4.5 loaded with curcumin interfere with α-synuclein aggregation

Curcumin (CUR) is a bioactive compound that has been proposed for the treatment of various neurodegenerative diseases. However, its use is limited due to its low solubility in aqueous media and chemical instability under physiological conditions. Herein, we propose a strategy to overcome these limitations by using PAMAM dendrimers of generation 4.5 (DG4.5). Using a combination of biophysical techniques together with in vitro models, we demonstrate that CUR-DG4.5 complexes: (i) increased the solubility and stability of CUR via internalization into dendrimer's pockets and interaction with terminal carboxylic groups; (ii) showed in vitro biocompatibility and increased CUR uptake; (iii) presented DPPH radical scavenging activity and in vitro inhibition of H2O2-induced stress; and (iv) interfere with α-synuclein aggregation. In conclusion, this work lays the foundation to use curcumin-loaded PAMAM dendrimers of generation 4.5 as nanodrugs capable of reducing oxidative stress and inhibiting α-synuclein aggregation to treat synucleinopathies.

Taurine alleviates oxidative stress in porcine mammary epithelial cells by stimulating the Nrf2-MAPK signaling pathway.

The high incidence of oxidative stress in sows during late gestation and lactation affects mammary gland health, milk yield, and milk quality. Recently, we found that supplementing maternal diets with 1% taurine improved antioxidant capability and enhanced growth performance in offspring; however, the mechanisms underlying these are unknown. This study aimed to investigate the cytoprotective effects and the mechanism of taurine in mitigating oxidative stress in porcine mammary epithelial cells (PMECs). PMECs were pretreated with 0-2.0 mM taurine for 12 h and then subjected to oxidative injury with 500 μM hydrogen peroxide (H2O2). Pretreatment with taurine attenuated decreased cell viability, enhanced superoxide dismutase, and reduced the intracellular reactive oxygen species accumulation after H2O2 exposure. Taurine also prevented H2O2-induced endoplasmic reticulum stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) was essential to the cytoprotective effects of taurine on PMECs, as Nrf2 knockdown significantly inhibited taurine-induced cytoprotection against oxidative stress. Moreover, we confirmed that Nrf2 induction by taurine was mediated through the inactivation of the p38/MAPK pathway. Overall, taurine supplementation has beneficial effects on redox balance regulation and may protect against oxidative stress in lactating animals.