Inhibition Of Lipid Peroxidation Research Articles

Antioxidant and Hepatoprotective Effect of Rosa davurica Pall Seed Oil on CCl4-Induced Acute Liver Injury in Mice.

The liver, being the most metabolically active organ, is highly vulnerable to damage caused by oxidative stress. Rosa davurica Pall. seed oil (RDPO), a novel vegetable oil, and its bioactive components have been extensively researched in the field of antioxidants. In this research, the antioxidant properties and hepatoprotection by RDPO were evaluated. A series of antioxidant evaluation systems and a CCl4-induced acute liver injury model in mice were used to investigate the antioxidant activity and hepatoprotective efficacy of RDPO. The results showed that the extraction rate of RDPO was 11.12% using the optimal extraction process. Three major unsaturated fatty acids of the oil were α-linolenic acid (11.89 ± 0.017%), linoleic acid (18.52 ± 0.072%), and oleic acid (11.54 ± 0.425%). Furthermore, its antioxidant small-molecule compounds were β-sitosterol (1.429 ± 0.002 μg/g), α-tocopherol (1.273 ± 0.079 μg/g), β-carotene (0.012 ± 0.001 μg/g), lycopene (0.108 ± 0.002 μg/g), squalene (178.950 ± 0.794 μg/g), total polyphenols (1.114 ± 0.032 μg GAE/mg), and total flavonoids (0.504 ± 0.009 mg RU/g), respectively. In vitro, RDPO significantly inhibited the production of ABTS+•, DPPH•, O2•-, and hydroxyl radicals, as well as Fe3+. In vivo, RDPO significantly reversed the activity of total superoxide-dismutase, catalase, L-glutathione, and the level of malondialdehyde (MDA) in liver tissue. It also obviously inhibited the activity of aspartate transaminase (AST) and the level of MDA in the serum. Therefore, RDPO has demonstrated excellent antioxidant activity and a potential liver protective effect. This effect may be ascribed to its capacity for decreasing AST activity, inhibiting lipid peroxidation, and boosting endogenous antioxidant enzyme activity. Therefore, RDPO has significant application value in the biopharmaceutical industry and as a dietary supplement.

Isoliquiritigenin alleviates myocardial ischemia-reperfusion injury by regulating the Nrf2/HO-1/SLC7a11/GPX4 axis in mice

Ischemia-reperfusion (I/R) injury, a multifaceted pathological process, occurs when the prolongation of reperfusion duration triggers ferroptosis-mediated myocardial damage. Isoliquiritigenin (ISL), a single flavonoid from licorice, exhibits a wide range of pharmacological impacts, but its function in ferroptosis caused by myocardial I/R injury remains unclear. This study delved into the protective effect of ISL on myocardial I/R injury-induced ferroptosis and its mechanism. Neonatal mouse cardiomyocytes (NMCM) underwent hypoxia/reoxygenation (H/R) to simulate the pathological process of myocardial I/R. ISL significantly attenuated H/R-triggered production of reactive oxygen species in NMCM, reduced the expression of malondialdehyde and the activity of lactate dehydrogenase, enhanced superoxide dismutase and catalase activity, and increased the expression of nuclear factor E2-related factor 2 (Nrf2) and its downstream heme oxygenase 1 (HO-1), thereby mitigating oxidative stress damage. CCK8 experiment revealed that the ferroptosis inhibitor Ferrostatin-1 significantly improved myocardial cell viability after 24 h of reoxygenation, and ISL treatment showed a similar effect. ISL reduced intracellular free iron accumulation, up-regulated glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) expression, and inhibited lipid peroxidation accumulation, thereby alleviating ferroptosis. The Nrf2-specific inhibitor ML385 counteracted ISL's defensive role against H/R-triggered oxidative stress damage and ferroptosis. In vivo experiments further confirmed that by regulating the translocation of Nrf2 into the nucleus, ISL treatment increased the levels of HO-1, GPX4, and SLC7A11, inhibited the expression of ACSL4, Drp1 to exert the antioxidant role, alleviated mitochondrial damage, and ferroptosis, ultimately reducing myocardial infarction area and injury induced by I/R. ML385 nearly abolished ISL's protective impact on the I/R model by inhibiting Nrf2 function. In summary, ISL is capable of mitigating oxidative stress, mitochondrial damage, and cardiomyocyte ferroptosis caused by I/R, thereby reducing myocardial injury. A key mechanism includes triggering the Nrf2/HO-1/SLC7A11/GPX4 pathway to prevent oxidative stress damage and cardiomyocyte ferroptosis caused by I/R.

Chiral thioacetyl derivatives of proline as novel potential agents for beluga reproduction

The aim of the research was to study antioxidant activity and protective potential of new phenol-containing thioacetyl derivatives of D- and L-prolines as potential agents on beluga sperm and survival in the early stages of ontogeny of bester (Huso x Acipenser ruthenus) development. The study indicated that both enantiomers demonstrated the equal scavenging activity towards DPPH•, ABTS•+, O2•–, H2O2 and NO, and that the activity towards all of these radicals, with the exception of nitric oxide, exceeded the activity of BHT. No significant differences were registered between the enantiomers in the inhibition of long-term lipid peroxidation of beluga sperm in vitro. The enantiomers revealed the opposite effect on the motility duration time of beluga spermatozoa, the rate of their fertilization, and survival at the early stages of bester ontogeny. Application of the L-proline derivative for the beluga sperm treatment resulted in the increase of the total period of movement of beluga sperm cells, the raise of the fertility of sterlet eggs and the survival of bester offspring at the prelarval stage, which led to an increase in the number of produced larvae. The introduction of the D-proline derivative or BHT decreased the motility duration time of beluga sperm, the fertility of sterlet eggs and the survival of offspring at the prolarval stage, which led to a decrease in the number of obtained larvae.

Effects of Berberine on Lipid Metabolism, Antioxidant Status, and Immune Response in Liver of Tilapia (Oreochromis niloticus) under a High-Fat Diet Feeding

Berberine, a natural alkaloid found abundantly in various medicinal plants, exhibits antioxidative, anti-inflammatory, and lipid metabolism-regulatory properties. Nonetheless, its protective effects and the molecular mechanisms underlying liver injury in fish have not been fully elucidated. The aims of this study were to investigate the antioxidative, anti-inflammatory, and lipid metabolism-regulating effects of berberine against high-fat diet (HFD)-induced liver damage and to clarify the underlying molecular mechanisms. Tilapia were fed diets containing two doses of berberine (50 and 100 mg/kg diet) alongside high fat for 60 days. The results showed that berberine treatments (50 and/or 100 mg/kg) significantly reduced elevated aminotransferases, triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) in the plasma. In the liver, berberine treatments significantly increased the expression of peroxisome proliferator-activated receptor α (pparα) and carnitine palmitoyltransferase 1 (cpt-1) genes, leading to a reduction in lipid accumulation. Meanwhile, berberine treatment suppressed lipid peroxidation formation and enhanced antioxidant capacity. Berberine upregulated the mRNA levels of erythroid 2-related factor 2 (nrf2) and its downstream genes including heme oxygenase 1 (ho-1) and glutathione-S-transferase (gstα). Additionally, berberine attenuated the inflammation by inhibiting the expression of toll-like receptor 2 (tlr2), myeloid differential protein-88 (myd88), relb, and inflammatory cytokines such as interleukin-1β (il-1β), tumor necrosis factor-α (tnf-α), and il-8. In summary, this study suggested that berberine offers protection against HFD-induced liver damage in tilapia via regulating lipid metabolism, antioxidant status, and immune response. This protective effect may be attributed to the modulation of the Nrf2, TLR2/MyD88/NF-κB, and PPARα signaling pathways.

The preventive effects of Saccharomyces boulardii against oxidative stress induced by lipopolysaccharide in rat brain

The brain is sensitive to oxidative stress, which can trigger microglial activation and neuroinflammation. Antioxidant therapies may provide neuroprotection against oxidative stress. In recent years antioxidant effects of probiotics and their possible mechanisms in oxidative stress-related models have been determined. In the current study, for the first time, we assessed the effects of Saccharomyces boulardii on oxidative stress provoked by lipopolysaccharide (LPS) in the rat brain. Four groups of animals were used, including the control, LPS, S. boulardii + LPS, and S. boulardii groups. All animals received either saline or S. boulardii (1010 CFU) by gavage for four weeks. Between days 14 and 22, all animals received either LPS (250 μg/kg) or saline by intraperitoneal (i.p.) injection. S. boulardii was able to inhibit lipid peroxidation and prevent the reduction of antioxidant levels, including glutathione and catalase in the model of oxidative stress induced by LPS in the rat hippocampus and cortex. Also, it increased the lowered ratio of glutathione/oxidized glutathione in both tissues. Serum levels of anti-inflammatory interleukin 10 (IL-10) and proinflammatory cytokines IL-6 and IL-8 increased and decreased, respectively. S. boulardii has potential antioxidant activities in oxidative stress-related model, possibly modulating gut microbiota, immune defense, and antioxidant enzyme activities that can be considered in preventing oxidative stress-related central nervous system (CNS) diseases.

In vitro assessment of antioxidant, antidiabetic, and cholesterol-modulating abilities of lactic acid bacteria: Implications for metabolic health and functional foods

This study aimed to demonstrate Lacticaseibacillus paracasei NWAFU334 (L. paracasei NWAFU334) and Limosilactobacillus fermentum NWAFU0035 (L. fermentum NWAFU0035) industrial applicability as functional agents with antioxidant and antidiabetic properties. The research unveiled their remarkable potential in cholesterol removal under challenging intestinal and gastric conditions. Notably, both strains demonstrated a spectrum of potent antioxidant activities, including scavenging of hydrogen peroxide, hydroxyl radicals, and DPPH free radicals, along with resistance to ABTS•+ radical cations. Similarly, they showed remarkable simulated gastric and intestinal fluid resistance, lipid peroxidation inhibition, notable inhibitory activities against α-glucosidase, and α-amylase, as well as exhibited exopolysaccharide production. The study highlighted the significance of L. paracasei NWAFU334 and L. fermentum NWAFU0035 in managing metabolic disorders and the exopolysaccharides production ability in enhancing human health and the food industry. This research provides a compelling foundation for advancing microbiology and functional foods as therapeutic supplements for metabolic disorders.

Effect of Curcuma longa on GPER-1 and Oxidative/Nitrosative Stress Biomarkers in Cardiac Ischemia-reperfusion Injury

Background: The death rate caused by cardiovascular diseases is increasing all over the world. To investigate the cardioprotective effects of Curcuma longa on cardiac ischemia-reperfusion (I/R) injury, which was further examined through G protein-coupled estrogen receptor 1 (GPER-1) and oxidative/nitrosative stress biomarkers. Methods: Twenty-four male Wistar-albino rats were divided into three groups (I/R group; n=8, sham group; n=8, treatment (Curcuma longa) group; n=8). 1 ml Curcuma longa 50 mg/kg was administered intraperitoneally in the treatment group. While catalase, superoxide dismutase and malondialdehyde values were measured by spectrophotometric method, the measurement of GPER-1 was performed by ELISA method. In the histopathological examination, the groups were evaluated in terms of hemorrhage, myocardial edema, myocytolysis and polymorphonuclear leukocyte (PMNL) infiltration. Result: Statistically significant differences were observed between the treatment and I/R groups in terms of oxidative stress (malondialdehyde) level and antioxidant enzyme activities (catalase, superoxide dismutase) (p less than 0.05). The GPER-1 level was higher in the treatment group compared to the I/R group (p less than 0.05). Histopathologically, PMNL infiltration, hemorrhage, edema and myocytolysis were observed in the I/R and sham groups, whereas only hemorrhage was detected in the treatment group. This study showed that treatment with Curcuma longa inhibited lipid peroxidation by restoring existing antioxidant enzymes against cardiac ischemia-reperfusion injuries.

Exploring the Wound Healing Potential of a Cuscuta chinensis Extract-Loaded Nanoemulsion-Based Gel

Cuscuta chinensis (C. chinensis) presents many pharmacological activities, including antidiabetic effects, and antioxidant, anti-inflammatory, and antitumor properties. However, the wound care properties of this plant have not yet been reported. Therefore, this research aimed to evaluate the antioxidant, anti-inflammatory, and antibacterial activities of ethanol and ethyl acetate C. chinensis extracts. The phytochemical markers in the extracts were analyzed using high-performance liquid chromatography (HPLC). Then, the selected C. chinensis extract was developed into a nanoemulsion-based gel for wound care testing in rats. The results showed that both of the C. chinensis extracts exhibited antioxidant activity when tested using 2,2-Diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and lipid peroxidation inhibition assays. They reduced the expression of IL-1β, IL-6, and TNF-α in RAW264.7 cells induced with lipopolysaccharide (LPS). The ethyl acetate extract also had antibacterial properties. Kaempferol was found in both extracts, whereas hyperoside was found only in the ethanol extract. These compounds were found to be related to the biological activities of the extracts, confirmed via molecular docking. The C. chinensis extract-loaded nanoemulsions had a small particle size, a narrow polydispersity index (PDI), and good stability. Furthermore, the C. chinensis extract-loaded nanoemulsion-based gel had a positive effect on wound healing, presenting a better percentage wound contraction Fucidin cream. In conclusion, this formulation has the potential for use as an alternative wound treatment and warrants further study in clinical trials.

Clinical Efficacy in Skin Hydration and Reducing Wrinkles of Nanoemulsions Containing Macadamia integrifolia Seed Oil.

This study aimed to assess natural oils for their antioxidant and anti-hyaluronidase properties and select the most effective candidate for development into nanoemulsions (NE) for clinical evaluations. The oils were assessed using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+) and ferric thiocyanate assays for antioxidant properties and an enzyme-substrate reaction assay for anti-hyaluronidase activity. The most potent oil was formulated into conventional emulsions (CE) and NE, which were characterized and evaluated for their stability, both in accelerated and long-term conditions. The irritation potential was assessed using both the hen's eggs chorioallantoic membrane test and a clinical trial. Skin hydration enhancement and skin wrinkle reduction efficacy were clinically assessed. Macadamia integrifolia oil exhibited significant potency as an ABTS•+ radical scavenger, lipid peroxidation inhibitor, and hyaluronidase inhibitor (p < 0.05). Both the CE and NE, comprising 15% w/w oil, 5% w/w Tween® 80 and Span® 80, and 80% w/w DI water, were found to be optimal. NE with an internal droplet size of 112.4 ± 0.8 nm, polydispersity index of 0.17 ± 0.01, and zeta potential of -31.5 ± 1.0 mV, had good stability and induced no irritation. Both CE and NE enhanced skin hydration and reduced skin wrinkles in human volunteers, while NE was outstanding in skin hydration enhancement.

Advances in Research on the Activity Evaluation, Mechanism and Structure-Activity Relationships of Natural Antioxidant Peptides.

Antioxidant peptides are a class of biologically active peptides with low molecular weights and stable antioxidant properties that are isolated from proteins. In this review, the progress in research on the activity evaluation, action mechanism, and structure-activity relationships of natural antioxidant peptides are summarized. The methods used to evaluate antioxidant activity are mainly classified into three categories: in vitro chemical, in vitro cellular, and in vivo animal methods. Also, the biological effects produced by these three methods are listed: the scavenging of free radicals, chelation of metal ions, inhibition of lipid peroxidation, inhibition of oxidative enzyme activities, and activation of antioxidant enzymes and non-enzymatic systems. The antioxidant effects of natural peptides primarily consist of the regulation of redox signaling pathways, which includes activation of the Nrf2 pathway and the inhibition of the NF-κB pathway. The structure-activity relationships of the antioxidant peptides are investigated, including the effects of peptide molecular weight, amino acid composition and sequence, and secondary structure on antioxidant activity. In addition, four computer-assisted methods (molecular docking, molecular dynamics simulation, quantum chemical calculations, and the determination of quantitative structure-activity relationships) for analyzing the structure-activity effects of natural peptides are summarized. Thus, this review lays a theoretical foundation for the development of new antioxidants, nutraceuticals, and cosmetics.

Salvia miltiorrhiza suppresses cardiomyocyte ferroptosis after myocardial infarction by activating Nrf2 signaling

Ethnopharmacological relevanceFerroptosis, a recently identified non-apoptotic form of cell death reliant on iron, is distinguished by an escalation in lipid reactive oxygen species (ROS) that are iron-dependent. This phenomenon has a strong correlation with irregularities in iron metabolism and lipid peroxidation. Salvia miltiorrhiza Bunge (DS), a medicinal herb frequently utilized in China, is highly esteemed for its therapeutic effectiveness in enhancing blood circulation and ameliorating blood stasis, particularly during the treatment of cardiovascular diseases (CVDs). Numerous pharmacological studies have identified that DS manifests antioxidative stress effects as well as inhibits lipid peroxidation. However, ambiguity persists regarding the potential of DS to impede ferroptosis in cardiomyocytes and subsequently improve myocardial damage post-myocardial infarction (MI). Aim of the studyThe present work focused on investigating whether DS could be used to prevent the ferroptosis of cardiomyocytes and improve post-MI myocardial damage. Materials and methodsIn vivo experiments: Through ligation of the left anterior descending coronary artery, we constructed both a wild-type (WT) and NF-E2 p45-related factor 2 knockout (Nrf2−/−) mouse model of MI. Effects of DS and ferrostatin-1 (Fer-1) on post-MI cardiomyocyte ferroptosis were examined through detecting ferroptosis and myocardial damage-related indicators as well as Nrf2 signaling-associated protein levels. In vitro experiments: Erastin was used for stimulating H9C2 cardiomyocytes to construct an in vitro ferroptosis cardiomyocyte model. Effects of DS and Fer-1 on cardiomyocyte ferroptosis were determined based on ferroptosis-related indicators and Nrf2 signaling-associated protein levels. Additionally, inhibitor and activator of Nrf2 were used for confirming the impact of Nrf2 signaling on DS's effect on cardiomyocyte ferroptosis. ResultsIn vivo: In comparison to the model group, DS suppressed ferroptosis in cardiomyocytes post-MI and ameliorated myocardial damage by inducing Nrf2 signaling-related proteins (Nrf2, xCT, GPX4), diminishing tissue ferrous iron and malondialdehyde (MDA) content. Additionally, it enhanced glutathione (GSH) levels and total superoxide dismutase (SOD) activity, effects that are aligned with those of Fer-1. Moreover, the effect of DS on alleviating cardiomyocyte ferroptosis after MI could be partly inhibited through Nrf2 knockdown. In vitro: Compared with the erastin group, DS inhibited cardiomyocyte ferroptosis by promoting the expression of Nrf2 signaling-related proteins, reducing ferrous iron, ROS, and MDA levels, but increasing GSH content and SOD activity, consistent with the effect of Fer-1. Additionally, Nrf2 inhibition increased erastin-mediated ferroptosis of cardiomyocytes through decreasing Nrf2 signaling-related protein expressions. Co-treatment with DS and Nrf2 activator failed to further enhance the anti-ferroptosis effect of DS. ConclusionMI is accompanied by cardiomyocyte ferroptosis, whose underlying mechanism is probably associated with Nrf2 signaling inhibition. DS possibly suppresses ferroptosis of cardiomyocytes and improves myocardial damage after MI through activating Nrf2 signaling.

Mesenchymal stem cell-derived exosomes overexpressing SRC-3 protect mice from cerebral ischemia by inhibiting ferroptosis

BackgroundThe treatment for cerebral ischemia remains limited, and new therapeutic strategies are urgently needed. Exosome has shown great promise for the treatment of cerebral ischemia. Steroid receptor coactivator-3 (SRC-3) was reported to be involved in neurological performances. In this study, we aimed to investigate the protective effects of mesenchymal stem cell (MSC)-derived exosomes overexpressing SRC-3 on cerebral ischemia in mice. MethodsThe mice were treated with an intracerebroventricular injection of GFP-overexpressed exosomes (GFP-exo) and SRC-3-overexpressed exosomes (SRC3-exo) in a middle cerebral artery occlusion (MCAO) model of cerebral ischemia. ResultsThe results showed that SRC3-exo treatment significantly inhibited lipid peroxidation and ferroptosis of the neurons subjected to oxygen-glucose deprivation. It further suppressed the activation of microglia and astrocytes, and decreased the production of pro-inflammatory cytokines in the brains of MCAO mice. Furthermore, SRC3-exo treatment reduced the water content of brain tissue and infarct size, which alleviated the neurological damage and improved neurological performances in the MCAO mice. ConclusionsOur results suggest that MSC-derived exosomes expressing SRC3 can be a therapeutic strategy for cerebral ischemia by inhibiting ferroptosis.

Unravelling the Influence of Chlorogenic Acid on the Antioxidant Phytochemistry of Avocado (Persea americana Mill.) Fruit Peel.

Oxidative stress is pivotal in the pathology of many diseases. This study investigated the antioxidant phytochemistry of avocado (Persea americana Mill.) peel. Different solvent extracts (dichloromethane, ethyl acetate, methanol, and water) of avocado peel were subjected to total phenol and flavonoid quantification, as well as in vitro radical scavenging and ferric reducing evaluation. The methanol extract was subjected to gradient column chromatographic fractionation. Fraction 8 (eluted with hexane:chloroform:methanol volume ratio of 3:6.5:0.5, respectively) was subjected to LC-MS analysis. It was assessed for cellular inhibition of lipid peroxidation and lipopolysaccharide (LPS)-induced ROS and NO production. The DPPH radical scavenging mechanism of chlorogenic acid was investigated using Density Functional Theory (DFT). The methanol extract and fraction 8 had the highest phenol content and radical scavenging activity. Chlorogenic acid (103.5 mg/mL) and 1-O-caffeoylquinic acid (102.3 mg/mL) were the most abundant phenolics in the fraction. Fraction 8 and chlorogenic acid dose-dependently inhibited in vitro (IC50 = 5.73 and 6.17 µg/mL) and cellular (IC50 = 15.9 and 9.34 µg/mL) FeSO4-induced lipid peroxidation, as well as LPS-induced ROS (IC50 = 39.6 and 28.2 µg/mL) and NO (IC50 = 63.5 and 107 µg/mL) production, while modulating antioxidant enzyme activity. The fraction and chlorogenic acid were not cytotoxic. DFT analysis suggest that an electron transfer, followed by proton transfer at carbons 3'OH and 4'OH positions may be the radical scavenging mechanism of chlorogenic acid. Considering this study is bioassay-guided, it is logical to conclude that chlorogenic acid strongly influences the antioxidant capacity of avocado fruit peel.

Cynarin alleviates acetaminophen-induced acute liver injury through the activation of Keap1/Nrf2-mediated lipid peroxidation defense via the AMPK/SIRT3 signaling pathway.

Overdose of Acetaminophen (APAP) is a major contributor to acute liver injury (ALI), a complex pathological process with limited effective treatments. Emerging evidence links lipid peroxidation to APAP-induced ALI. Cynarin (Cyn), a hydroxycinnamic acid derivative, exhibits liver protective effects, but whether it mitigates APAP-induced ALI is unclear. Our aim was to verify the protective impact of Cyn on APAP-induced ALI and elucidate the molecular mechanisms governing this process. Herein, the regulation of the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) interaction was determined to be a novel mechanism underlying this protective impact of Cyn against APAP-induced ALI. Nrf2 deficiency increased the severity of APAP-induced ALI and lipid peroxidation and counteracted the protective effect of Cyn against this pathology. Additionally, Cyn promoted the dissociation of Nrf2 from Keap1, enhancing the nuclear translocation of Nrf2 and the transcription of downstream antioxidant proteins, thereby inhibiting lipid peroxidation. Molecular docking demonstrated that Cyn bound competitively to Keap1, and overexpression of Keap1 reversed Nrf2-activated anti-lipid peroxidation. Additionally, Cyn activated the adenosine monophosphate-activated protein kinase (AMPK)/sirtuin (SIRT)3 signaling pathway, which exhibits a protective effect on APAP-induced ALI. These findings propose that Cyn alleviates APAP-induced ALI by enhancing the Keap1/Nrf2-mediated lipid peroxidation defense via activation of the AMPK/SIRT3 signaling pathway.

Smart chitosan nanogel for targeted doxorubicin delivery, ensuring precise release, and minimizing side effects in Ehrlich ascites carcinoma-bearing mice

In recent decades, bio-polymeric nanogels have become a forefront in medical research as innovative in-vivo drug carriers. This study introduces a meticulously pH-sensitive chitosan nanoparticles/P(N-Isopropylacrylamide-co-Acrylic acid) nanogel (CSNPs/P(NIPAm-co-AAc)), making significant advancements. The nanogel effectively encapsulated doxorubicin hydrochloride (Dx. HCl), a model drug, within its compartments through accurate electrostatic binding. Comparing nano chitosan (CSNPs) before and after integrating copolymerized P(NIPAm-co-AAc), highlighting an improved and adaptable nanogel structure with responsive behaviors. The intraperitoneal delivery of Dx-loaded nanogel (Dx@N.gel) to Ehrlich ascites carcinoma (Eh)-bearing mice at doses equivalent to 1.5 and 3 mg/kg of Dx per day for 14 days exhibited superiority over the administration of free Dx. Dx@N.gel demonstrated heightened anticancer activity, significantly improving mean survival rates in Eh mice. The nanogel's multifaceted defense mechanism mitigated oxidative stress, inhibited lipid peroxidation, and curbed nitric oxide formation induced by free Dx. It effectively countered hepatic DNA deterioration, normalized elevated liver and cardiac enzyme levels, and ameliorated renal complications. This pH-responsive CSNPs/P(NIPAm-co-AAc) nanogel loaded with Dx represents a paradigm shift in antitumor drug delivery. Its efficacy and ability to minimize side effects, contrasting sharply with those of free Dx, offer a promising future where potent cancer therapies seamlessly align with patient well-being.

Centella asiatica transfersomes and Bergamot essential oil nanoemulsion combined in gel exhibited anti-photoaging effects on UVB-radiated BALB/c mice

Photoaging of skin tissue can result from exposure to ultraviolet B (UVB) radiation. This study developed two nanocarriers Centella asiatica (CA) transfersomes (TF) and Bergamot essential oil (BEO) nanoemulsions (NE) combined in a gel formulation as a drug delivery system, in order to study whether they could synergize to prevent UVB radiation and provide anti-photoaging effects. Nanoencapsulation of CA-TF and BEO-NE were examined for their quality by characterizing their physicochemical properties. An in vivo study evaluated topically applied CA-TF and BEO-NE combination gels biological effect on BALB/c mice before UVB radiation (840 mJ/cm2) for two weeks. Particle size analysis of developed nanocarriers exhibited monodispersed pattern with an average particle size and zeta potential of around 9.64 ± 0.35 nm and −39.86 ± 1.33 mV, respectively. In vivo experiments showed that topically applied CA-TF and BEO-NE combination gel significantly prevented UVB-induced wrinkle formation and skin erythema and inhibited histological damage, including epidermal hyperplasia, collagen fibers, and the destruction of elastic fibers. Additionally, the CA-TF and BEO-NE combination gel reduced UVB-induced oxidative stress by increasing superoxide dismutase (SOD) activity and suppressed lipid peroxidation by decreasing malondialdehyde (MDA) expression as well as inhibiting the expression of UVB-induced pro-inflammatory cytokines include tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6). Moreover, the CA-TF and BEO-NE combination gel increased the type I collagen expression, restoring UVB-induced collagen production and density. Therefore, nanoencapsulation CA-TF and BEO-NE combination gel could synergistically prevent UVB-induced oxidative stress and inflammatory responses.

Peroxiredoxin 6 suppresses ferroptosis in lung endothelial cells

Peroxiredoxin 6 (Prdx6) repairs peroxidized membranes by reducing oxidized phospholipids, and by replacing oxidized sn-2 fatty acyl groups through hydrolysis/reacylation by its phospholipase A2 (aiPLA2) and lysophosphatidylcholine acyltransferase activities. Prdx6 is highly expressed in the lung, and intact lungs and cells null for Prdx6 or with single-point mutations that inactivate either Prdx6-peroxidase or aiPLA2 activity alone exhibit decreased viability, increased lipid peroxidation, and incomplete repair when exposed to paraquat, hyperoxia, or organic peroxides. Ferroptosis is form of cell death driven by the accumulation of phospholipid hydroperoxides. We studied the role of Prdx6 as a ferroptosis suppressor in the lung. We first compared the expression Prdx6 and glutathione peroxidase 4 (GPx4) and visualized Prdx6 and GPx4 within the lung. Lung Prdx6 mRNA levels were five times higher than GPx4 levels. Both Prdx6 and GPx4 localized to epithelial and endothelial cells. Prdx6 knockout or knockdown sensitized lung endothelial cells to erastin-induced ferroptosis. Cells with genetic inactivation of either aiPLA2 or Prdx6-peroxidase were more sensitive to ferroptosis than WT cells, but less sensitive than KO cells. We then conducted RNA-seq analyses in Prdx6-depleted cells to further explore how the loss of Prdx6 sensitizes lung endothelial cells to ferroptosis. Prdx6 KD upregulated transcriptional signatures associated with selenoamino acid metabolism and mitochondrial function. Accordingly, Prdx6 deficiency blunted mitochondrial function and increased GPx4 abundance whereas GPx4 KD had the opposite effect on Prdx6. Moreover, we detected Prdx6 and GPx4 interactions in intact cells, suggesting that both enzymes cooperate to suppress lipid peroxidation. Notably, Prdx6-depleted cells remained sensitive to erastin-induced ferroptosis despite the compensatory increase in GPx4. These results show that Prdx6 suppresses ferroptosis in lung endothelial cells and that both aiPLA2 and Prdx6-peroxidase contribute to this effect. These results also show that Prdx6 supports mitochondrial function and modulates several coordinated cytoprotective pathways in the pulmonary endothelium.

Identification of a targeted ACSL4 inhibitor to treat ferroptosis-related diseases.

Ferroptosis is a form of iron-dependent, lipid peroxidation-driven regulatory cell death that has been implicated in the pathogenesis of multiple diseases, including organ injury, ischemia/reperfusion, and neurodegenerative diseases. However, inhibitors that directly and specifically target ferroptosis are not yet available. Here, we identify the compound AS-252424 (AS) as a potent ferroptosis inhibitor through kinase inhibitor library screening. Our results show that AS effectively inhibits lipid peroxidation and ferroptosis in both human and mouse cells. Mechanistically, AS directly binds to the glutamine 464 of ACSL4 to inhibit its enzymatic activity, resulting in the suppression of lipid peroxidation and ferroptosis. By using nanoparticle-based delivery systems, treatment with AS-loaded nanoparticles effectively alleviate ferroptosis-mediated organ injury in mouse models, including kidney ischemia/reperfusion injury and acute liver injury (ALI). Thus, our results identify that AS is a specific and targeted inhibitor of ACSL4 with remarkable antiferroptosis function, providing a potential therapeutic for ferroptosis-related diseases.

Involvement of ferroptosis in eribulin-induced cytotoxicity in ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) is a unique clinicopathological subtype of epithelial ovarian cancer that is resistant to standard chemotherapy. Eribulin, a microtubule dynamics inhibitor of halichondrin class, has unique effects in the cancer microenvironment such as induction of epithelization and reduction in metastatic potential in breast cancer cells; however, nothing is known about the effect of eribulin and the detailed mechanisms in OCCC. This study aimed to investigate the involvement of ferroptosis and its mechanism in the antitumor activity of eribulin in OCCC cells and a mouse xenograft model. We found that eribulin-induced cell death was reduced by ferroptosis inhibitors; deferoxamine, an iron chelator and ferrostatin-1, a lipid peroxidation inhibitor. Eribulin increased the levels of intracellular iron, reactive oxygen species (ROS), and lipid peroxides, and increased the mitochondrial membrane potential. Eribulin downregulated the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH), and superoxide dismutase (SOD) activity. The combination of eribulin and ML210, a glutathione peroxidase 4-inhibiting ferroptosis inducer, had a synergistic effect on ferroptosis. Taken together, our findings show firstly that eribulin triggers ferroptosis in OCCC and this effect occurs via the suppression of the Nrf2–HO-1 signaling pathway, SOD activity and the promotion of lipid peroxidation. These findings suggest that eribulin-induced ferroptosis is associated with its anti-tumor effect and also could be a potential therapeutic target in OCCC.

Abstract 358: Ferroptosis modulates melanoma progression in an age-specific manner through changes in the tumor microenvironment

Abstract Aging is an independent prognostic factor for melanoma, the most aggressive form of skin cancer. Although immune therapy has shown a dramatic improvement in melanoma treatment, resistance to it still occurs in some patients. Higher oxidative damage in tumor cells as well as lipid and iron accumulation are singular characteristics of the aged tumor microenvironment (TME). Here, we investigate the impact of these characteristics of the aged TME in the promotion of ferroptosis, a caspase independent iron mediated type of cell death, and as possible modulators of the response to checkpoint blockade therapy. Lipid peroxidation levels were assessed through immunohistochemical staining for the marker 4-HNE in tumors of young and aged mice injected intradermally with Yumm1.7 cells.Correlation analysis between transcriptomic data (TCGA-SKCM) was performed to identify common denominators among proteins associated with the aged TME, ferroptosis pathway and IFN-y signaling. Our in vitro experiments consisted of viability assays with combinations of IFN-y, young and aged skin fibroblast conditioned media (CM), arachidonic acid (AA) or ferroptosis inducers such as RSL-3. Protein levels of ferroptosis related markers in melanoma cells treated with fibroblast conditioned media, and in Wnt5a high/low cell lines were analyzed through western blot (WB). Tumors from aged mice showed stronger staining with 4-HNE antibody when compared to young. Wnt5a (present in the aged TME) showed a strong correlation with several ferroptosis related transcripts. WB analysis of Wnt5a high/low lines indicate differences in GPX4, FTL1, SLC3A2, GCH1 and DHODH. Wnt5a levels show an inverse correlation with ferroptosis resistance and anti-ferroptotic proteins. Our data indicate that aged TME favors ferroptosis death in melanoma cells. To understand how ferroptosis impacts tumor growth in young and aged mice, we used a syngeneic tumor model injecting Yumm1.7 cells intra-dermally in mice and treated with a lipid peroxidation inhibitor, Liproxstatin, or an ferroptosis inducer, IKE. Liproxstatin lead to reduced tumor growth only in young mice followed by changes in immune cell populations such as monocytes and macrophages. IFNy induction of these events might be associated with changes in proteins of the pathway or alterations in fatty acid uptake as suggested by lipid accumulation and AA potentiation of its cytotoxic effects. Further exploration of ferroptosis will impact our understanding on how aged TME modulates immune cell killing and provide evidence to target or revert resistance to checkpoint blockade therapy associated with an IFN-y signature and new strategies for treatment of older patients. Citation Format: Murilo R. Rocha, Yash Chhabra, Laura Huser, Elizabeth Irene Harper, Agrani Dixit, Vania Wang, Alexis E. Carey, Cheyenne Palm, Fan Huang, Ashani T. Weeraratna. Ferroptosis modulates melanoma progression in an age-specific manner through changes in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 358.