Free Radical Research最新文献

Diabetic nephropathy (DN) is a major complication driven by inflammation and oxidative stress (OS); mitochondrial reactive oxygen species (mtROS)-activated NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome-induced pyroptosis is a key mechanism. Carnosine, notably an endogenous dipeptide with antioxidant and anti-glycation effects, has renoprotective potential but its mechanism remains unclear. High glucose (HG)-treated HK-2 cells were used as an in vitro model. We assessed cell viability, mtROS, and the expression of AMP-activated protein kinase (AMPK)/sirtuin 3 (SIRT3)/superoxide dismutase 2 (SOD2) and NLRP3 pathway proteins using Western blot and quantitative real-time PCR (qPCR). Pyroptotic cell death was confirmed by measuring the cleavage of gasdermin D (GSDMD) and lactate dehydrogenase (LDH) release. The roles of SIRT3 and AMPK were validated using small interfering RNA (siRNA) and a pharmacological inhibitor. Cellular adenosine triphosphate (ATP) levels were measured to assess the bioenergetic status. Carnosine reversed HG-induced decreases in cell viability and increases in mtROS. HG conditions also led to a significant depletion of cellular ATP, which was partially restored by carnosine. Mechanistically, carnosine activated the AMPK/SIRT3 axis, promoting the deacetylation and activation of SOD2. This suppressed NLRP3 inflammasome activation, evidenced by reduced levels of NLRP3, ASC, cleaved caspase-1, as well as reduced cleavage of GSDMD into its N-terminal fragment (GSDMD-N), reduced LDH release, and downstream cytokines. These protective effects were dependent on both AMPK and SIRT3. Carnosine protects renal tubular cells from HG-induced injury by alleviating mitochondrial OS and subsequent NLRP3 inflammasome-mediated pyroptosis through the activation of the AMPK/SIRT3/SOD2 signaling pathway. This activation is likely mediated by carnosine's ability to restore cellular bioenergetics.

Acorus gramineus has long been used in East Asia and exhibits diverse biological activities, yet its effects on melanogenesis under oxidative stress remain unclear. This study evaluated the antioxidant capacity of Acorus gramineus ethanol extract (AGEE) and its regulatory effects on melanogenesis in B16F1 melanoma cells under normal and oxidative stress conditions. AGEE showed concentration-dependent antioxidant activity in DPPH radical scavenging, reducing power, hydroxyl radical scavenging, and lipid peroxidation assays, while maintaining low cytotoxicity up to 25 µg/mL. In cell-free systems, AGEE directly inhibited mushroom tyrosinase activity and L-DOPA oxidation. In cellular models, AGEE significantly reduced melanin production under both basal and H₂O₂-induced oxidative stress conditions, with stronger inhibition observed in oxidatively damaged cells, even during α-MSH stimulation. Western blot analysis indicated that oxidative stress decreased melanogenesis-related proteins, including MITF, TYR, TRP-1, and TRP-2. Although α-MSH partially restored MITF expression, AGEE co-treatment attenuated α-MSH-induced MITF upregulation and suppressed downstream melanogenic enzymes in a concentration-dependent manner. Immunofluorescence analysis confirmed reduced MITF and TYR signals following AGEE treatment. Collectively, AGEE exerts multi-level inhibitory effects on melanogenesis via direct enzymatic inhibition, modulation of MITF-dependent pathways, and attenuation of oxidative stress. AGEE effectively suppresses melanogenic activation under both normal and oxidative stress conditions, with enhanced efficacy in redox-imbalanced environments. These findings suggest AGEE as a promising functional ingredient for managing oxidative stress-associated hyperpigmentation.

Normal cells preferably utilize mitochondrial oxidative phosphorylation as the primary source of energy in aerobic conditions. However, superoxide anions (^.O₂^-) are produced as a by-product due to leakage of the electron from the electron transport chain during oxidative phosphorylation, and cells are continuously exposed to elevated levels of superoxide. Superoxide dismutase 2 (SOD2, also called manganese superoxide dismutase or MnSOD) is a mitochondria-matrix-localized antioxidant enzyme that prevents oxidative damage to mitochondria by converting ^.O₂^- to hydrogen peroxide (H₂O₂). Previous studies reported the roles of SOD2 in regulating cellular metabolism and the connection of variable SOD2 levels and activity with diverse types and stages of cancer. In this review, we systematically summarize recent findings on the roles of SOD2 in cancer cell proliferation, cell cycle progression, invasion, metastasis, metabolic reprogramming, apoptosis, autophagy, angiogenesis, and immune response. Understanding the regulatory factors and signaling pathways of cancer development and progression mediated by SOD2 could help to target critical cellular vulnerabilities to develop novel therapeutic strategies against cancer.

Nonsmall cell lung cancer (NSCLC) is the predominant form of lung cancer. Ferroptosis is a novel therapeutic target against treatment resistance in NSCLC. However, its regulation by m6A RNA modification remains incompletely elucidated. m6A RNA modification mediates mRNA stability, translation, and splicing to target transcripts. Methyltransferase like 7B (METTL7B) has been implicated in tumor progression, but its role in NSCLC ferroptosis via m6A modification has not been reported. We aimed to investigate the mechanism of METTL7B-mediated m6A modification in NSCLC cell ferroptosis. NSCLC cells (SK-MES-1/PC9/H1975/A549) and normal cells (BEAS-2B) were cultured. The expression of METTL7B, long non-coding RNA 02159 (LINC02159), and aryl hydrocarbon receptor nuclear translocator-like 2 (ARNTL2) was determined. After METTL7B knockdown, cell viability was measured by MTT assay; ferroptosis-related factors were analyzed. m6A quantification was performed. m6A enrichment on LINC02159 was analyzed. The interaction between LINC02159 and KAT2A was verified. KAT2A and H3K27ac enrichment on the ARNTL2 promoter was detected. The roles of LINC02159 and ARNTL2 were validated. METTL7B, LINC02159, and ARNTL2 were upregulated in NSCLC cells compared to BEAS-2B cells. METTL7B knockdown increased iron ions, reactive oxygen species, and malondialdehyde levels and decreased cell viability, superoxide dismutase, and glutathione levels. METTL7B potentially upregulated LINC02159 expression through m6A modification. LINC02159 may recruit KAT2A to enhance H3K27ac enrichment on the ARNTL2 promoter, thereby promoting ARNTL2 expression. Overexpression of LINC02159 or ARNTL2 partially reversed the pro-ferroptotic effects of METTL7B knockdown on NSCLC cells. In conclusion, METTL7B inhibits ferroptosis in NSCLC cells via the LINC02159/KAT2A/ARNTL2 axis in an m6A-dependent manner.

High copper diet intake detriment animal health and livestock profitability. As a key polyamine, spermidine modulates critical physiological processes, include regulating autophagy and oxidative stress. However, the effect of spermidine in mitigating intestinal oxidative stress triggered by high copper diet has yet to be fully elucidated. In this study, eight-week male C57BL/6J mice were fed either a normal diet or a high-copper diet, supplemented with spermidine through water alone or in combination. The intestinal morphology was analyzed using HE staining, intestinal index, antioxidant capacity, SIgA, the content of copper ion, serum IgA, IgG and D-LA were detection. 16S rRNA was used to assess intestinal microbiota composition. The results showed that high copper diet intake disrupted intestinal morphology, elevated jejunum copper levels by 97% (p < 0.05), increased MDA by 31% and T-AOC by 54% in the duodenum (p < 0.05). Similarly, jejunum MDA increase by 49% and SOD rose by18% (p < 0.05). However, compared to CuSO₄ group, spermidine co-treatment improved duodenum villus-crypt ratio by 37% and enhanced serum IgG and IgA concentrations by 16% and 33% (p < 0.05). Microbial analysis via 16S rRNA sequencing revealed that spermidine reduced Staphylococcus abundance while promoting norank_f_Muribaculaceae. In conclusion, these findings suggest that spermidine supplementation restores intestinal architecture, boosts beneficial microbiota (e.g. Firmicutes, unclassified_f_Lachnospiraceae), and enhances antioxidant markers (SOD, T-AOC) and immune function (IgA).

Oxidative stress within the follicular microenvironment plays a critical role in oocyte quality and reproductive outcomes. This prospective study examines the association between follicular fluid redox status, maternal age, ovarian reserve, and clinical outcomes in women undergoing in vitro fertilization. Follicular fluid samples were obtained from women undergoing fresh embryo transfer cycles and analyzed for oxidative damage markers (malondialdehyde, nitric oxide, ischemia-modified albumin, sialic acid) and antioxidant parameters (superoxide dismutase, catalase, glutathione, and thiol-disulfide homeostasis). Participants were stratified according to maternal age (≤35 vs. >35 years), serum estradiol levels on the day of human chorionic gonadotropin trigger (≤90th vs. >90th percentile), and clinical pregnancy outcome. Anti-Müllerian hormone and follicle-stimulating hormone levels were recorded as indicators of ovarian reserve. Women aged >35 years exhibited significantly higher malondialdehyde and sialic acid levels, accompanied by reduced antioxidant enzyme activities. Cycles resulting in clinical pregnancy showed lower oxidative stress and higher antioxidant capacity compared with non-pregnant cycles. Malondialdehyde levels correlated positively with age and follicle-stimulating hormone, while antioxidant parameters correlated positively with anti-Müllerian hormone and pregnancy outcome. Receiver operating characteristic analysis demonstrated moderate discriminative ability of malondialdehyde, superoxide dismutase, catalase, and glutathione for clinical pregnancy. These findings indicate that age-related redox imbalance in follicular fluid is associated with diminished ovarian reserve and reduced in vitro fertilization success. Assessment of follicular fluid oxidative stress parameters may provide clinically relevant insights into female reproductive potential.

Ulcerative colitis (UC), a major form of inflammatory bowel disease (IBD), is characterized by chronic inflammation and ulceration of the colonic mucosa. Its etiology is multifactorial, involving genetic, environmental, and immune factors. Recent evidence highlights the crucial role of ferroptosis, an iron-dependent regulated cell death pathway, in UC pathogenesis. Ferroptosis is marked by excessive accumulation of lipid peroxides, reactive oxygen species, and iron overload, all contributing to epithelial injury. The 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model closely mimics human UC and demonstrates elevated free iron, increased malondialdehyde levels, and decreased glutathione peroxidase 4 expression hallmarks of ferroptotic damage. These molecular disturbances lead to oxidative stress, epithelial barrier dysfunction, and sustained inflammation. Importantly, ferroptosis inhibition shows therapeutic potential. Small-molecule inhibitors such as Ferrostatin-1 and Liproxstatin-1 effectively reduce mucosal damage and restore antioxidant balance, while iron chelators like deferoxamine alleviate iron overload and ROS generation. Moreover, natural compounds including curcumin, resveratrol, epigallocatechin-3-gallate, baicalein, and quercetin demonstrate anti-ferroptotic activity by modulating the nuclear factor erythroid 2-related factor 2/Heme oxygenase-1 pathway, enhancing glutathione peroxidase 4 function, and maintaining iron homeostasis. Collectively, these findings establish ferroptosis as a pivotal mechanism in TNBS-induced UC, linking oxidative stress and iron dysregulation to mucosal injury. Targeting ferroptosis offers a promising therapeutic avenue for UC management, though further clinical and translational studies are needed to validate its efficacy and safety.

Non-thermal plasma (NTP) has been reported to exhibit various biological effects, including hemostatic, anticancer, and wound-healing properties. However, the effects of NTP on allergic responses in mast cells and basophils have not been sufficiently investigated. In this study, we examined the effects of NTP on immunoglobulin E (IgE)-mediated degranulation and cytokine expression in the basophilic cell line RBL-2H3. To induce degranulation and cytokine expression as part of allergic reactions, we treated the cells with 2,4-dinitrophenylated bovine serum albumin (BSA) after sensitization or with the Ca²⁺ ionophore A23187. Cells were also treated with NTP-activated acetated Ringer's solution (PAA). Degranulation was measured by quantifying the β-hexosaminidase (β-hex) activity. PAA treatment inhibited both antigen stimulation- and A23187-induced degranulation in RBL-2H3 cells, and suppressed antigen-induced mRNA expression of cytokines, including IL-4, IL-6, and TNF-α. Antigen stimulation caused disintegration of the F-actin cytoskeleton, and PAA treatment suppressed these morphological changes. Cotreatment with PAA and catalase blocked the inhibitory effects of PAA on antigen stimulation-induced degranulation. PAA also inhibited A23187-induced extracellular signal-regulated kinase (ERK) phosphorylation and antigen stimulation- or store-operated Ca²⁺ entry inducer thapsigargin-induced cellular Ca²⁺ influx. These results indicate that PAA effectively inhibits immunological responses in allergic cells - such as degranulation and cytokine expression - by suppressing ERK phosphorylation and Ca²⁺ influx. These findings suggest that PAA may be an effective therapeutic option for treating patients with allergic diseases.

Avenanthramides (AVAs), unique polyphenols in oats, have received much attention due to their biologically beneficial properties. Herein, density functional theory (DFT) calculations and molecular docking were performed to elucidate the structure-antioxidant capacity relationship and underlying mechanism of A-type AVAs under physiological conditions. Further, the interaction effects between AVAs and Kelch-like ECH-associated protein 1 (Keap1) for activating the Nrf2-ARE (nuclear factor-E2-related factor 2-antioxidant response element) signaling pathway were explored. The results showed that the representative A-type AVA 2 c_d displayed excellent HOO^• scavenging capacity in water at physiological pH with an overall rate constant (k_overall = 2.97 × 10⁷ M^-1 s^-1) higher than that of reference antioxidants Trolox and BHT, while moderate capacity in lipid-like media. Formal hydrogen atom transfer (fHAT) mechanism is more favored in lipid media, whereas in aqueous solution at physiological pH, the hydrogen transfer from dianion species plays a dominant role (99.4%) in the overall reactivity. The results also highlighted the effects of central double bond, hydroxyl, carboxyl and solvents in antiradical processes. Molecular docking and DFT calculations showed that 2c and 2 c_d can bind strongly to Keap1 through hydrogen bonding and cysteine residues based covalent binding, which disrupts the Keap1-Nrf2 interaction. Collectively, 2c and 2 c_d are promising candidates as multifunctional antioxidant with radical trapping and Nrf2 activation effects.

With lung cancer rates climbing steadily, the development of effective prevention strategies has become more crucial than ever. Our previous research has revealed that ginger oil possesses potential lung cancer preventive activity, demonstrating inhibitory effects against tobacco carcinogen 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung cancer in A/J mice. 6-Gingerol, a bioactive compound from ginger (Zingiber officinale Rosc.), exhibits multiple pharmacological activities. However, the preventive efficacy of 6-Gingerol against tobacco carcinogen-induced lung cancer remains unclear. This study investigated the chemopreventive effects of 6-Gingerol on NNK-induced lung tumorigenesis in A/J mice and Beas-2b cells. Results indicated that 6-Gingerol significantly reduced lung tumor count and improved tissue structure compared to NNK alone. In vitro, 6-Gingerol protected Beas-2b cells from NNK-induced damage. Mechanistically, 6-Gingerol activated the Nrf2 pathway, enhancing antioxidant enzyme expression and reducing oxidative stress. Additionally, 6-Gingerol exhibited anti-inflammatory effects by inhibiting the NNK-activated TLR4/NF-κB pathway. In conclusion, 6-Gingerol shows significant chemopreventive effects against NNK-induced lung cancer via activating Nrf2 and suppressing TLR4/NF-κB, underscoring its potential as a preventive agent functional food in lung cancer development.