Alveolar bone injury represents a prevalent clinical challenge in dentistry, for which stem cell-based therapy has emerged as a promising strategy to promote bone regeneration. N-acetylcysteine (NAC), a potent antioxidant, has been shown to modulate the PI3K-AKT signalling pathway and potentially enhance osteogenesis; however, the specific downstream effectors mediating this process remain unidentified. In this study, post-extraction serum metabolomic profiling revealed that alveolar bone injury is accompanied by systemic oxidative stress and metabolic remodelling. Transcriptomic analysis of antioxidant-treated dental stem cells further identified type VI collagen A1 (COL6A1) as a key functional mediator. We subsequently investigated the role of COL6A1 in antioxidant-mediated osteogenesis through immunofluorescence and protein assays, and performed knockdown and in vivo experiments to evaluate its function in oxidative stress regulation and osteogenic differentiation. Our results demonstrated that alveolar bone injury is associated with systemic oxidative stress and global metabolic alterations. In vitro, NAC markedly promoted the osteogenic differentiation of dental follicle stem cells (DFSCs) by activating the PI3K-AKT pathway and upregulating COL6A1. COL6A1 knockdown resulted in elevated reactive oxygen species (ROS) levels, impaired mitochondrial function, and attenuated NAC-mediated osteogenesis. In vivo, NAC-treated DFSCs exhibited enhanced bone healing and extracellular matrix (ECM) deposition in a rat model of alveolar bone injury, effects that were mediated through COL6A1 upregulation. Collectively, these findings demonstrate that NAC enhances osteogenesis in DFSCs via the PI3K-AKT-COL6A1 axis, offering a promising antioxidant-based strategy for stem cell therapies in bone regeneration. Moreover, COL6A1 is essential for maintaining redox homeostasis and represents a potential therapeutic target for improving regenerative outcomes.

Polysubstance use, particularly opioid-stimulant co-use, is a public health concern associated with higher overdose risk and poor treatment outcomes. Preclinical evidence suggests that oxycodone withdrawal increases cocaine consumption and disrupts nucleus accumbens glutamate homeostasis. N-acetylcysteine (NAC), a cysteine prodrug that restores glutamate homeostasis, has shown preclinical promise in reducing drug seeking in single substance seeking models. However, no studies have evaluated the efficacy of NAC in reducing behavioral outcomes, including self-administration, following opioid-stimulant polysubstance use. Here, we evaluated NAC as a pharmacotherapeutic for oxycodone-cocaine sequential use using our previously established rat intravenous self-administration model, which utilized an A-B-A-B design. We previously found that rats increase cocaine consumption during oxycodone withdrawal. Thus, here, we tested if NAC could reduce this effect and reduce oxycodone self-administration. Male and female rats first underwent oxycodone or food self-administration acquisition, followed by cocaine self-administration in Phase 2. Rats were subsequently treated with NAC (100 mg/kg) or vehicle during Phase 3, where the reinforcer switched back to the one presented in Phase 1. In Phase 4, we assessed cocaine self-administration and somatic signs during an oxycodone-free period. NAC treatment did not alter oxycodone or cocaine consumption, response discrimination, or somatic signs during drug onboard and drug-free periods. Cocaine consumption was inversely associated with somatic signs at early but not more protracted timepoints independent of NAC treatment. While NAC did not attenuate cocaine or oxycodone intake-related behaviors in our sequential use model, these results underscore the need for expanded polysubstance use pharmacotherapeutic and model development. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

While standard high fat diets cause hyperphagia and obesity in mice, high fat-low carbohydrate ketogenic diets (KDs) reduce food intake and body weight. Because the basis for this difference is still unclear, we systematically altered the macronutrient content of a standard KD and found that feeding C57BL/6J (B6J) mice a KD with 5% protein resulted in hypophagia, weight loss, and hypoglycemia, whereas the same diet with 10% protein led to increased adiposity and glucose intolerance. However, these effects were strain-dependent as C57BL/6NJ (B6NJ) weighed similar amounts on the two diets leading us to investigate the molecular mechanisms. When fed the KD-5% diet, B6J but not B6NJ mice showed increased levels of two anorexigenic factors, GDF15 and LCN2, and loss of function of either blunted the weight loss of B6J mice fed the diet. B6J mice harbor mutations in Nnt (Nicotinamide nucleotide transhydrogenase) and Nlrp12 (NLR family pyrin domain containing 12), both of which are wildtype in B6NJ mice. B6J mice fed the KD-5% diet showed the RNA signature of oxidative and integrated stress responses (ISR) and restoring NNT function in liver reduced the levels of GDF15. RNA-seq also revealed that B6J but not B6NJ mice had the RNA signature for hepatic inflammation and a knockout of Nlrp12 led B6NJ mice to lose weight on the KD-5% diet with increased levels of LCN2. Suppression of oxidative stress with N-acetylcysteine (NAC) reduced expression of both GDF15 and LCN2 and prevented the weight loss associated with the KD-5% protein diet in B6J mice, whereas inhibition of the integrated stress response with ISRIB only attenuated the GDF15 axis. Collectively, these findings explain why B6J mice lose weight on a ketogenic diet and reveal a critical interplay between macronutrient composition and genetic background leading to increased levels of GDF15 and LCN2 to induce hypophagia. Finally, these data suggest that the response to different diets among humans might be similarly variable based on genetic variation and macronutrient composition, suggesting the possible need for personalized dietary interventions.

Proteoglycans are a major component of the connective tissue matrix, which consists of a core protein and covalently attached glycosaminoglycan (GAG) chains, which are highly sulfated polysaccharides with a tetrasaccharide linker for the core protein attachment. Impaired synthesis or degradation of GAG causes genetic disorders. In the 1950s, deficient lysosomal GAG degradation was discovered in mucopolysaccharidoses. In the 1990s, a defective enzyme for GAG synthesis was implicated in a variant of Ehlers-Danlos syndrome and an impaired GAG sulfation in diastrophic dysplasia. Newer studies have uncovered that abnormal GAG synthesis causes a large group of genetic skeletal disorders with joint and skin abnormalities.

Female fertility relies on tightly regulated mitochondrial bioenergetics to support oocyte maturation, fertilization, and early embryonic development. Beyond ATP generation, mitochondria orchestrate redox signaling, calcium homeostasis, metabolic-epigenetic coupling, and nuclear-mitochondrial communication, thereby shaping oocyte competence and ovarian longevity. Aging, obesity, metabolic stress, and genetic perturbations disrupt these regulatory networks, leading to redox imbalance, impaired oxidative phosphorylation, altered mitochondrial dynamics, and mitochondrial DNA instability. These changes compromise granulosa cell support, impair meiotic progression, and accelerate ovarian aging, contributing to female infertility disorders such as polycystic ovary syndrome. This review integrates therapeutic strategies that actively reprogram ovarian mitochondrial function rather than merely counteracting damage. Mitochondria-targeted antioxidants-including melatonin, resveratrol, N-acetylcysteine, mitochondria-directed scavengers, and coenzyme Q10 restore redox balance, stabilize mitochondrial dynamics, and enhance oocyte bioenergetics. In parallel, metabolic modulators such as metformin, dapagliflozin, and glucagon-like peptide-1 receptor agonists reprogram ovarian bioenergetics by reshaping substrate utilization, suppressing inflammatory and oxidative signaling, and improving mitochondrial efficiency within the ovary. Collectively, these interventions demonstrate that, positioning mitochondria-centered therapies as promising strategies to preserve fertility and extend the female reproductive health span.

The endoplasmic reticulum (ER) to Golgi secretory compartment of eukaryotic cells is highly sensitive to changes in intracellular homeostasis. Using a primary screening assay that monitors the function of this pathway, we prioritized a cyanobacterial extract from the Red Sea that decreased secretion of a bioluminescent reporter, Gaussia luciferase (GLuc), in living cells. A comparison of LCMS2 data against the GNPS database revealed a match for macrocyclic depsipeptide hoiamide A (1). Biological testing confirmed the ability of 1 to induce a mixed, non-lethal stress response in human U87-MG glioblastoma cells; analysis of stress markers by qRT-PCR revealed early upregulation of superoxide dismutase 1 (SOD1) and C/EBP-homologous protein (CHOP) relative to the control. Co-treatment of cells with 1 (100 nM to 3 μM) and antioxidant N-acetylcysteine afforded full protection from 1-induced decreases in GLuc secretion. We report that terminally differentiated human SH-SY5Y neuroblastoma cells, with a neuron-like phenotype, are highly sensitive to nanomolar concentrations of 1, whereas undifferentiated cells remained viable at 3 μM. These results expand the known biology of hoiamides and suggest that neurotoxic potential of 1 is likely due to an inherent failure of neurons to adapt to the loss of redox homeostasis and sustained ER stress.

Cysteine is a sulfur-containing amino acid that plays a central role in skin physiology through thiol-mediated redox regulation and glutathione (GSH) synthesis. It critically influences melanogenesis, collagen homeostasis, and wound healing. However, its clinical application is limited by poor stability and bioavailability. In this review, we provide a mechanistic and comparative analysis of cysteine and its derivatives, including N-acetylcysteine (NAC), cysteinamide (C-NH2), GSH, and related compounds. These derivatives regulate melanogenesis by modulating dopaquinone pathways and tyrosinase activity, maintain collagen balance by preserving redox-sensitive enzymatic processes, and enhance wound healing through antioxidant and anti-inflammatory mechanisms. Importantly, chemical modifications such as acetylation, amidation, and esterification improve pharmacokinetic properties, enabling more effective intracellular delivery. Furthermore, different derivatives exhibit distinct advantages depending on biological context, highlighting the importance of compound selection. Overall, cysteine derivatives emerge as promising therapeutic candidates for dermatological applications, particularly in pigmentation disorders and impaired wound healing. Future studies should focus on in vivo validation and clinical translation.

Background/Objectives: The flavonoid quercetin (Q) has recently been suggested as a natural anti-aging and senolytic agent. However, its low stability and poor oral bioavailability may limit its efficacy. To address this, we investigated whether a lecithin-based formulation of Q, Quercefit™ (QF), enhances stress resistance and delays aging in vivo. Methods: The nematode Caenorhabditis elegans was used as an animal model to evaluate the effects of QF under physiological and stress conditions. Unformulated Q was administered as a control. Worm survival, healthspan, resistance to thermal and oxidative stress, and expression of stress- and longevity-related genes were assessed. All the experiments were conducted at least in triplicate, each including a minimum of 15 worms. The data were analyzed using Student's t-test, one-way or two-way ANOVA, and Bonferroni's post hoc test. Results: One hundred micromolar Q administered in QF was more effective than equimolar unformulated Q in increasing the worms' ability to resist acute thermal stress at 35 °C (tested on 75 worms/group) and oxidative stress caused by 0.5 mM hydrogen peroxide (tested on 75 worms/group). In this last case, the protective effect of QF was similar to that of N-acetylcysteine and ascorbic acid. Under experimental conditions mimicking the long-term consequences of thermal stress, QF, like Q, increased the worms' lifespan and healthspan by approximately 50%, counteracting the age-related decline associated with stress (120 worms/group). These benefits are supported by QF's capacity to act as a reactive oxygen species scavenger; suppress heat-shock element gene transcription activated by thermal stress, such as hsp-16.2 and hsp-70, and stimulate the sod-3 and gst-4 genes that are involved in antioxidant and detoxification responses. Conclusions: These findings suggest that Q, when administered in the QF formulation, can act at the transcriptional level to protect against aging induced by stressful conditions.

Background: There is a growing number of studies suggesting the effectiveness of dietary supplements in preventing and treating endometriosis. It has been suggested that deficiencies in vitamins D and E as well as zinc are associated with the increased risk of endometriosis development. Beneficial effects of magnesium, curcumin, resveratrol and epigallocatechin-3-gallate were found in experimental animal studies. A reduction in pain related to endometriosis was shown in women using omega-3 and alpha-lipoic acid. Meanwhile, decreasing endometriotic lesion size after the supplementation of omega-3, N-acetylcysteine, vitamin C and epigallocatechin-3-gallate was observed in animal and human studies. Thus, the aim of this critical review was to summarize the available data describing the effects of dietary supplements used in the treatment of endometriosis. Material and Methods: The PubMed, Embase, Cochrane, and Web of Science databases were searched for related studies until 15 December 2025. Finally, 34 studies were included in the synthesis. Results: Of these 34 studies, only 23 were randomized, placebo-controlled trials. There have been no RCTs evaluating the effectiveness of vitamin E, zinc, alpha-LA, EGCG and DIM in the treatment of endometriosis. Single studies evaluating the effectiveness of vitamin C, magnesium, resveratrol, NAC and PEA with PLD have not confirmed it. Meanwhile single studies evaluating the effectiveness of selenium, propolis and quercetin have confirmed it. Of the four studies assessing the effectiveness of vitamin D, two confirmed it and two did not; of the two studies assessing probiotics, one confirmed its effectiveness and one did not; of the two studies assessing curcumin, one confirmed its effectiveness and one did not; and of the three studies assessing omega-3, two confirmed its effectiveness and one did not. All four RCTs assessing the combination of vitamins C and E confirmed their effectiveness. Conclusions: Despite encouraging observations from experimental studies, the results of RCTs are less encouraging and do not allow for the formulation of recommendations concerning the use of supplements in the treatment of endometriosis symptoms according to EBM.

Background/Objectives: Oxidative stress plays an important role in the pathophysiology of endometriosis, contributing to inflammation, immune dysregulation, and lesion progression. This has led to growing interest in antioxidant-based strategies as potential supportive interventions. Methods: A literature search was conducted using PubMed, Scopus, and Web of Science databases, covering studies published from database inception until the end of January 2026. The review focused on clinically relevant endpoints, including pain intensity, markers of inflammation and oxidative stress, reproductive parameters, and quality of life. Results: Among the analyzed interventions, the most consistent clinical effects were observed with melatonin, with randomized controlled trials indicating a moderate reduction in pain. N-acetylcysteine shows potentially beneficial effects; however, the available clinical data remain limited and heterogeneous. For other supplements, the evidence is inconsistent or insufficient to support clear clinical conclusions, and in many cases relies on indirect or mechanistic findings rather than well-established clinical outcomes. Conclusions: Current evidence does not support the use of non-mineral antioxidant supplements as standalone therapy for endometriosis. They may be considered as adjunctive strategies, although their clinical effectiveness remains uncertain and requires confirmation in well-designed randomized clinical trials.

This study aimed to investigate the effects of resveratrol (RES) and carboplatin (CPT), alone and in combination, on cell viability, apoptosis, cell cycle progression, mitochondrial function, and oxidative stress in Y79 retinoblastoma (RB) cells. Particular emphasis was placed on evaluating the synergistic potential of the combination and elucidating the interconnected molecular mechanisms underlying its anticancer effects. Y79 cells were treated with RES, CPT, and their combinations. Cell viability and synergy were assessed using the MTT assay and combination index (CI) analysis. Apoptosis (annexin V/PI), cell cycle distribution (propidium iodide (PI) staining), intracellular ROS production (DCFH-DA), and mitochondrial membrane potential (JC-1) were evaluated by flow cytometry. ROS dependency was further examined using N-acetylcysteine (NAC) pretreatment. Expression levels of apoptosis- and cell cycle-related genes (BAX, BCL-2, CASP3, CASP9, CCNB1, and CDK1) were analyzed by RT-qPCR. Cytoskeletal alterations were assessed by immunocytochemistry. In addition, the antitumor effects of the combination were validated in a three-dimensional (3D) tumor spheroid model. RES and CPT reduced cell viability in a dose- and time-dependent manner and demonstrated synergistic effects (CI < 1) at selected concentrations. Combination treatment significantly increased apoptosis, induced G2/M phase arrest, enhanced ROS accumulation, and promoted mitochondrial depolarization compared with single-agent treatments. NAC pretreatment attenuated ROS generation and partially restored cell viability, supporting a contributory role of oxidative stress in combination-induced cytotoxicity. At the transcriptional level, the RES + CPT combination significantly increased the BAX/BCL-2 ratio and upregulated CASP3 and CASP9 expression, while downregulating CCNB1 and CDK1, consistent with mitochondrial apoptotic activation and G2/M arrest. Immunocytochemical analysis revealed pronounced cytoskeletal disruption and apoptotic morphology in the combination group. Importantly, in the 3D spheroid model, co-treatment markedly reduced spheroid size and viability and enhanced cell death compared with monotherapies. The combination of RES and CPT exerts a synergistic anticancer effect in Y79 RB cells through coordinated mechanisms involving ROS accumulation, mitochondrial dysfunction, caspase activation, and G2/M phase arrest. The attenuation of cytotoxicity by NAC and the validation of efficacy in a 3D tumor spheroid model strengthen the mechanistic relevance of these findings. These results support further preclinical investigation of this combination strategy in in vivo models and normal retinal cell systems.