Iron Chelator Research Articles

Analysis Of The Cost Effectiveness Of Oral Iron Cleaning Drugs Between Deferipron And Deferasiroks In Patients With Thalasemia Major At Bhayangkara Kindergarten Hospital. Ii Setukpa Lemdiklat Polri

Thalassemia is a blood disorder characterized by reduced or absent synthesis of globin chains, particularly thalassemia major, imposes significant financial burdens due to the lifelong need for blood transfusions and iron chelation drugs. This research aims to assess the cost and efficacy of oral iron chelators, specifically deferasirox and deferiprone, in treating thalassemia major patients at Setukpa Lemdiklat Polri Tk—II Hospital in 2023. The data were retrospectively gathered through total sampling from patients' medical records and the hospital information system. The findings indicate that the average total treatment cost for thalassemia major patients using deferasirox (IDR 52,969,775,-) is higher than deferiprone (IDR 49,407,613,-). Deferasirox exhibits greater effectiveness (1,364 ng/mL) than deferiprone (1,210 ng/mL). The cost-effectiveness ratio of deferasirox (IDR 38,834,-) is lower than that of deferiprone (IDR 40,833,-). Transitioning from deferiprone to deferasirox incurs an additional IDR 23,130 per unit cost. The average cost-effectiveness ratio suggests that deferasirox is more economically efficient than deferiprone.thalassemia major

Phytochemical characterization and biological activities of Inula viscosa L. Aiton: a promising plant from Turkey

ABSTRACT The methanol extract of Inula viscosa (IVM) was investigated for its antioxidant potential using the DPPH and ABTS radical scavenging as well as iron chelating assays (ICA). The total phenol (TPC) and flavonoid contents (TFC) of IVM were determined using the Folin-Ciocalteu and aluminum trichloride methods, respectively. Antimicrobial activity of different concentrations of I. viscosa methanol extract was investigated by disc diffusion and broth microdilution method. The IVM extract was found to be containing TPC (236.78 ± 7.63 mg GAE/g) and TFC (94.36 ± 1.86 mg QE/g). Antioxidant activity IC50 values for the DPPH, ABTS and ICA assays were found to be 277.7 ± 3.68, 2.44 ± 0.02, and 222.1 ± 0.71 µg/mL, respectively. The MIC values of the IVM on the tested microorganisms ranged from 0.48 to 7.81 mg/mL. Furthermore, IVM extract was demonstrated 18.32 ± 1.37%, 23.06 ± 1.05%, 4.72 ± 0.13%, 15.13 ± 0.37% and 37.64 ± 4.02% inhibition against tyrosinase, α-amylase, α-glucosidase, AChE and BChE, respectively. In the results of LC-MS/MS analysis, acacetin, quercetin, chlorogenic acid and protocatechuic acid were determined as most dominant compounds. These findings suggested that this plant may be a natural resource for creating novel medicinal compounds.

A 38 Week and 2 Day G1P0A0 Primigravida in the First Stage of Labor with Thalassemia: A Case Report

Thalassemia is one of the most prevalent inherited blood disorders worldwide. We reported a case of 20-year-old G1P0A0 pregnant woman diagnosed with thalassemia intermedia since childhood based on chronic anemia, facies Cooley, and family history. She had 6 times red blood cell transfusion throughout current pregnancy. On 38 week 2 day gestation, she was admitted with chief complaint of painful regular uterine contractions and bloody show. Physical and laboratory findings were low hemoglobin, hematocrit, MCV, and MCH. Thalassemia can be alpha or beta type, depending on the affected globin chain. Clinical severity varies. The main therapies are repeated blood transfusions and iron chelation. During pregnancy, optimal evaluation and management are crucial to prevent maternal and fetal complications. This patient will undergo cesarean section and needs thorough high-risk antenatal care.

Audiologic and vestibular assessment in children and adolescents with transfusion dependent beta thalassemia major: The era of deferasirox film coated tablet

BackgroundHearing impairment has frequently been described in β-thalassemia patients with a significant impact on the patients’ quality of life. Most studies provided evidence of deferoxamine (DFO) dose-related ototoxicity, however, the data is scarce regarding deferasirox (DFX) as a sole iron chelator. AimWe aimed to assess the prevalence and risk factors of sensorineural hearing loss (SNHL) and vestibular dysfunction in regularly transfused β-thalassemia patients who had been treated with DFX film coated tablets. MethodsWe conducted a case control study on 57 transfusion dependent β-thalassemia patients with a mean age of 15.3 years who received DFX FCT as monotherapy for at least one consecutive year, and 57 healthy age and sex-matching controls. Comprehensive audiological evaluations using pure tone audiometry (PTA) and transient evoked otoacoustic emission (TEOAE) as well as vestibular evaluation using Video-nystagmography (VNG) were done. ResultsSNHL was identified in 12 patients (21.1 %) using PTA and a statistically significant difference was detected between controls and patients at 6 KHz and 12 KHz frequencies. A higher incidence of SNHL was detected using TEOAE, 22 patients (43.1 %) failed to pass TEOAE, with a statistically significant decrease in the signal at frequencies 1, 4 KHz bilaterally and at frequencies 1.5, 2 KHz in the right ear compared to controls. Canal paresis was detected in 21 (36.8 %) of thalassemic children using bithermal caloric test with significantly more unilateral weakness than control children (P = 0.008). We found no significant correlation between audio-vestibular dysfunction and age, sex, serum ferritin, frequency of blood transfusion and dose of DFX FCT in thalassemic children. ConclusionWe conclude that the incidence of SNHL and vestibular dysfunction was high among transfusion dependent β-thalassemia patients. Therefore, we recommend performing pre-treatment baseline audio-vestibular assessment and yearly audio-vestibular monitoring to early detect high risk patients and initiate timely management to prevent permanent damage.

Luspatercept for the treatment of congenital sideroblastic anemia: Two case reports

Congenital sideroblastic anemia (CSA) is a group of disorders caused by different genetic mutations that result in low iron utilization and ineffective erythropoiesis. Current treatments are limited, and some patients do not respond to vitamin B6 therapy. Luspatercept is a novel erythropoietic maturation agent approved for adult β-thalassemia and Myelodysplastic syndromes with ring sideroblasts (MDS-RS) associated with ineffective erythropoiesis. Here we report 2 patients with CSA due to mutations in ALAS2 and SLC25A38 genes who became unresponsive after a period of treatment with vitamin B6 and iron chelators but achieved transfusion independence and a markedly reduced spleen after combination with luspatercept.

Deferoxamine reduces endothelial ferroptosis and protects cerebrovascular function after experimental traumatic brain injury

Cerebrovascular dysfunction resulting from traumatic brain injury (TBI) significantly contributes to poor patient outcomes. Recent studies revealed the involvement of iron metabolism in neuronal survival, yet its effect on vasculature remains unclear. This study aims to explore the impact of endothelial ferroptosis on cerebrovascular function in TBI. A Controlled Cortical Impact (CCI) model was established in mice, resulting in a significant increase in iron-related proteins such as TfR1, FPN1, and FTH, as well as oxidative stress biomarker 4HNE. This was accompanied by a decline in expression of the ferroptosis inhibitor GPX4. Moreover, Perls' staining and nonhemin iron content assay showed iron overload in brain microvascular endothelial cells (BMECs) and the ipsilateral cortex. Immunofluorescence staining revealed more FTH-positive cerebral endothelial cells, consistent with impaired perfusion vessel density and cerebral blood flow. As a specific iron chelator, deferoxamine (DFO) treatment inhibited such ferroptotic proteins expression and the accumulation of lipid‐reactive oxygen species following CCI, enhancing glutathione peroxidase (GPx) activity. DFO treatment significantly reduced iron deposition in BMECs and brain tissue, and increased density of the cerebral capillaries as well. Consequently, DFO treatment led to improvements in cerebral blood flow (as measured by laser speckle imaging) and behavioral performance (as measured by the neurological severity scores, rotarod test, and Morris water maze test). Taken together, our results indicated that TBI induces remarkable iron disorder and endothelial ferroptosis, and DFO treatment may help maintain iron homeostasis and protect vascular function. This may provide a novel therapeutic strategy to prevent cerebrovascular dysfunction following TBI.

Osteoblast Transcriptome Changes During Iron Deficiency

Introduction:Chronic kidney disease (CKD) often results in iron deficiency anemia and bone loss. Previously, iron deficiency was found to impede normal osteoblast differentiation. To investigate regulatory mechanisms elicited by iron deficiency we utilized unbiased RNA-sequencing to evaluate transcriptome-level changes over the course of differentiation.
 Methods:Mouse progenitor clone 2 (MPC-2) cells were differentiated in osteogenic media with or without an iron chelator, deferoxamine (DFO; 5 μM). RNA was extracted at 3, 7, and 14 days after initiating differentiation. Library generation and sequence alignment was performed by the Center for Medical Genomics (CMG). Count-based algorithms implemented in R packages (edgeR and limma-voom; default parameters) identified differentially expressed genes between cells in the control and DFO treatment.
 Results:RNA sequencing illustrated transcriptome changes due to iron deficiency including 63 upregulated/81 downregulated genes at day 3, 371 upregulated/780 downregulated genes at day 7, and 342 upregulated/739 downregulated genes at day 14. Importantly, day 14 controls clustered as transcriptional distinct whereas day 14 DFO treated cells clustered with early time points. As expected, genes involved in bone mineralization were suppressed with DFO including Dmp1 (logFC: -5.92, p= 5.7e-10) and Phex (logFC: -4.17, p= 5.5e-16). Interestingly, genes such as Ces2e, Gdf15, and Ano3, not previously found associated with osteoblasts, were significantly upregulated after 3 days with DFO (logFC: 5.14, 2.7, and 2.5 respectively).
 Conclusions:Transcriptomic changes occur even within 3 days of exposure to iron deficiency. Next steps include performing functional enrichment analysis, and validating expression level changes in vitro as well as within in vivo models of CKD-mediated bone loss.
 Scientific Impact and implications:Iron deficiency is intricately linked to impaired osteoblast function. Understanding the underlying molecular mechanisms could elucidate novel avenues for anabolic bone therapies in CKD.

Deferoxamine Intradermal Delivery Patch for Treatment of a Beta-Thalassemia Wound.

In this study, we present the first-in-human use of topical deferoxamine (DFO) in the treatment of a beta-thalassemia wound. We elected to use DFO on a patient that suffered from a chronic nonhealing wound in the setting of beta-thalassemia. Despite approximately 55 weeks of marginal improvement in healing, this patient's wound healed completely after 21 weeks of treatment with DFO. We believe that DFO has the potential to accelerate healing in beta-thalassemia wounds through iron chelation.

A Water-Soluble Chitosan Derivative for the Release of Bioactive Deferoxamine.

Deferoxamine (DFO) is a water-soluble iron chelator used pharmacologically for the management of patients with transfusional iron overload. However, DFO is not cell-permeable and has a short plasma half-life, which necessitates lengthy parenteral administration with an infusion pump. We previously reported the synthesis of chitosan (CS) nanoparticles for sustained slow release of DFO. In the present study, we developed solid dispersions and nanoparticles of a carboxymethyl water-soluble chitosan derivative (CMCS) for improved DFO encapsulation and release. CS dispersions and nanoparticles with DFO have been prepared by ironical gelation using sodium triphosphate (TPP) and were examined for comparison purposes. The successful presence of DFO in CMCS polymeric dispersions and nanoparticles was confirmed through FTIR measurements. Furthermore, the formation of CMCS nanoparticles led to inclusion of DFO in an amorphous state, while dispersion of DFO in the polymeric matrix led to a decrease in its crystallinity according to X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results. An in vitro release assay indicated sustained release of DFO from CS and CMCS nanoparticles over 48 h and 24 h, respectively. Application of CMCS-DFO dispersions to murine RAW 264.7 macrophages or human HeLa cervical carcinoma cells triggered cellular responses to iron deficiency. These were exemplified in the induction of the mRNA encoding transferrin receptor 1, the major iron uptake protein, and the suppression of ferritin, the iron storage protein. Our data indicate that CMCS-DFO nanoparticles release bioactive DFO that causes effective iron chelation in cultured cells.

Pharmacological activation of GPX4 ameliorates doxorubicin-induced cardiomyopathy

Due to the cardiotoxicity of doxorubicin (DOX), its clinical application is limited. Lipid peroxidation caused by excessive ferrous iron is believed to be a key molecular mechanism of DOX-induced cardiomyopathy (DIC). Dexrazoxane (DXZ), an iron chelator, is the only drug approved by the FDA for reducing DIC, but it has many side effects and cannot be used as a preventive drug in clinical practice. Single-nucleus RNA sequencing (snRNA-seq) analysis identified myocardial and epithelial cells that are susceptible to DOX-induced ferroptosis. The glutathione peroxidase 4 (GPX4) activator selenomethione (SeMet) significantly reduced polyunsaturated fatty acids (PUFAs) and oxidized lipid levels in vitro. Consistently, SeMet significantly decreased DOX-induced lipid peroxidation in H9C2 cells and mortality in C57BL/6 mice compared to DXZ, ferrostatin-1, and normal saline. SeMet can effectively reduce serum markers of cardiac injury in C57BL/6 mice and breast cancer patients. Depletion of the GPX4 gene in C57BL/6 mice resulted in an increase in polyunsaturated fatty acid (PUFA) levels and eliminated the protective effect of SeMet against DIC. Notably, SeMet exerted antitumor effects on breast cancer models with DOX while providing cardiac protection for the same animal without detectable toxicities. These findings suggest that pharmacological activation of GPX4 is a valuable and promising strategy for preventing the cardiotoxicity of doxorubicin.

A new ROS response factor YvmB protects Bacillus licheniformis against oxidative stress under adverse environment.

Bacillus spp., a class of aerobic bacteria, is widely used as a biocontrol microbe in the world. However, the reactive oxygen species (ROS) will accumulate once the aerobic bacteria are exposed to environmental stresses, which can decrease cell activity or lead to cell death. Hydroxyl radical (·OH), the strongest oxide in the ROS, can damage DNA directly, which is generated through Fenton Reaction by H2O2 and free iron. Here, we proved that the synthesis of pulcherriminic acid (PA), an iron chelator produced by Bacillus spp., could reduce DNA damage to protect cells from oxidative stress by sequestrating excess free iron, which enhanced the cell survival rates in stressful conditions (salt, antibiotic, and high temperature). It was worth noting that the synthesis of PA was found to be increased under oxidative stress. Thus, we demonstrated that the YvmB, a direct negative regulator of PA synthesis cluster yvmC-cypX, could be oxidized at cysteine residue (C57) to form a dimer losing the DNA-binding activity, which led to an improvement in PA production. Collectively, our findings highlight that YvmB senses ROS to regulate PA synthesis is one of the evolved proactive defense systems in bacteria against adverse environments.IMPORTANCEUnder environment stress, the electron transfer chain will be perturbed resulting in the accumulation of H2O2 and rapidly transform to ·OH through Fenton Reaction. How do bacteria deal with oxidative stress? At present, several iron chelators have been reported to decrease the ·OH generation by sequestrating iron, while how bacteria control the synthesis of iron chelators to resist oxidative stress is still unclear. Our study found that the synthesis of iron chelator PA is induced by reactive oxygen species (ROS), which means that the synthesis of iron chelator is a proactive defense mechanism against environment stress. Importantly, YvmB is the first response factor found to protect cells by reducing the ROS generation, which present a new perspective in antioxidation studies.

Identification of a system for hydroxamate xenosiderophore-mediated iron transport in Burkholderia cenocepacia.

One of the mechanisms employed by the opportunistic pathogen Burkholderia cenocepacia to acquire the essential element iron is the production and release of two ferric iron chelating compounds (siderophores), ornibactin and pyochelin. Here we show that B. cenocepacia is also able to take advantage of a range of siderophores produced by other bacteria and fungi ('xenosiderophores') that chelate iron exclusively by means of hydroxamate groups. These include the tris-hydroxamate siderophores ferrioxamine B, ferrichrome, ferricrocin and triacetylfusarinine C, the bis-hydroxamates alcaligin and rhodotorulic acid, and the monohydroxamate siderophore cepabactin. We also show that of the 24 TonB-dependent transporters encoded by the B. cenocepacia genome, two (FhuA and FeuA) are involved in the uptake of hydroxamate xenosiderophores, with FhuA serving as the exclusive transporter of iron-loaded ferrioxamine B, triacetylfusarinine C, alcaligin and rhodotorulic acid, while both FhuA and FeuA are able to translocate ferrichrome-type siderophores across the outer membrane. Finally, we identified FhuB, a putative cytoplasmic membrane-anchored ferric-siderophore reductase, as being obligatory for utilization of all of the tested bis- and tris-hydroxamate xenosiderophores apart from alcaligin.

Post-transfusion severe headache in a patient with thalassemia with superficial siderosis of the central nervous system: a case report and literature review

BackgroundPatients with severe thalassemia may experience adverse effects from transfusion such as fever, rash, and iron overload after long-term transfusion therapy. Severe headaches as a side effect of blood transfusion in patients with thalassemia are not commonly observed, especially when combined with superficial siderosis of the central nervous system, which is easily misdiagnosed and requires excessive examination and treatment.Case PresentationA 31-year-old woman was admitted with severe headache and vomiting over 3 days following blood transfusion. She was diagnosed with intermediate α-thalassemia at 2 years of age and had a history of irregular blood transfusions. Physical examination revealed horizontal nystagmus with no other abnormal neurological signs. Magnetic resonance (MR) imaging, MR venography, MR arteriography, and cerebrospinal fluid analysis were normal. However, susceptibility-weighted imaging showed abnormal signals in the bilateral and fourth ventricles. Initial antibiotics, antivirals, decompression of intracranial pressure, iron chelation, and symptomatic treatments were administered; subsequently, small intermittent blood transfusions were cautiously administered for severe anemia. The patient’s headache was gradually relieved, and she was discharged on day 9. At the 5-month follow-up, the patient’s headache recurred following another transfusion.ConclusionsSevere post-transfusion headache in patients with thalassemia has not been fully recognized and is easily misdiagnosed, leading to excessive examination and treatment. Understanding the clinical features of transfusion-related headaches can help identify this complication, but the exact pathophysiological mechanism requires further research.

Phosphoproteomics implicates glutamatergic and dopaminergic signalling in the antidepressant-like properties of the iron chelator deferiprone

BackgroundCurrent antidepressants have limitations due to insufficient efficacy and delay before improvement in symptoms. Polymorphisms of the serotonin transporter (5-HTT) gene have been linked to depression (when combined with stressful life events) and altered response to selective serotonergic reuptake inhibitors. We have previously revealed the antidepressant-like properties of the iron chelator deferiprone in the 5-HTT knock-out (KO) mouse model of depression. Furthermore, deferiprone was found to alter neural activity in the prefrontal cortex of both wild-type (WT) and 5-HTT KO mice. MethodsIn the current study, we examined the molecular effects of acute deferiprone treatment in the prefrontal cortex of both genotypes via phosphoproteomics analysis. ResultsIn WT mice treated with deferiprone, there were 22 differentially expressed phosphosites, with gene ontology analysis implicating cytoskeletal proteins. In 5-HTT KO mice treated with deferiprone, we found 33 differentially expressed phosphosites. Gene ontology analyses revealed phosphoproteins that were predominantly involved in synaptic and glutamatergic signalling. In a drug-naïve cohort (without deferiprone administration), the analysis revealed 21 differentially expressed phosphosites in 5-HTT KO compared to WT mice. We confirmed the deferiprone-induced increase in tyrosine hydroxylase serine 40 residue phosphorylation (pTH-Ser40) (initially revealed in our phosphoproteomics study) by Western blot analysis, with deferiprone increasing pTH-Ser40 expression in WT and 5-HTT KO mice. ConclusionAs glutamatergic and synaptic signalling are dysfunctional in 5-HTT KO mice (and are the target of fast-acting antidepressant drugs such as ketamine), these molecular effects may underpin deferiprone's antidepressant-like properties. Furthermore, dopaminergic signalling may also be involved in deferiprone's antidepressant-like properties.

Rosmarinic Acid Liposomes Downregulate Hepcidin Expression via BMP6-SMAD1/5/8 Pathway in Mice with Iron Overload.

The objective of this study is to examine the potential protective effect of rosmarinic acid (RosA) encapsulated within nanoliposomes (RosA-LIP) on hepatic damage induced by iron overload. The characteristics, stability, and release of RosA-LIP in vitro were identified. The mice were randomly assigned to five groups: Control, Model, Model+DFO (DFO), Model+RosA (RosA), and Model+RosA-LIP (RosA-LIP). The iron overload model was induced by administering iron dextran (i.p.). The DFO, RosA, and RosA-LIP groups received iron dextran and were subsequently treated with DFO, RosA, and RosA-LIP for 14 days. We developed a novel formulation of RosA-LIP that exhibited stability and controlled release properties. Firstly, RosA-LIP improved liver function and ameliorated pathological changes in a mouse model of iron overload. Secondly, RosA-LIP demonstrated the ability to enhance the activities of T-SOD, GSH-Px, and CAT, while reducing the levels of MDA and 4-HNE, thereby effectively mitigating oxidative stress damage induced by iron overload. Thirdly, RosA-LIP reduced hepatic iron levels by downregulating FTL, FTH, and TfR1 levels. Additionally, RosA-LIP exerted a suppressive effect on hepcidin expression through the BMP6-SMAD1/5/8 signaling pathway. Furthermore, RosA-LIP upregulated FPN1 expression in both the liver and duodenum, thereby alleviating iron accumulation in these organs in mice with iron overload. Notably, RosA exhibited a comparable iron chelation effect, and RosA-LIP demonstrated superior efficacy in mitigating liver damage induced by excessive iron overload. RosA-LIP exhibited favorable sustained release properties, targeted delivery, and efficient protection against iron overload-induced liver damage. A schematic representation of the proposed protective mechanism of rosmarinic acid liposome during iron overload. Once RosA-LIP is transported into cells, RosA is released. On the one hand, RosA attenuates the BMP6-SMAD1/5/8-SMAD4 signaling pathway activation, leading to inhibiting hepcidin transcription. Then, the declined hepcidin contacted the inhibitory effect of FPN1 in hepatocytes and duodenum, increasing iron mobilization. On the other hand, RosA inhibits TfR1 and ferritin expression, which decreases excessive iron and oxidative damage.

A New Concept in Antidiabetic Therapeutics: A Concerted Removal of Labile Iron and Intracellular Deposition of Zinc.

The inflammatory process is known to be an integral part of the pathophysiology of type 2 diabetes mellitus (T2DM). The "labile," redox-active iron, serving as a catalyst in Fenton reaction, producing the deleterious reactive oxygen species, triggering and maintaining inflammation, is hypothesized to play a causative role in this process. Concenter Biopharma continued the development of a new platform of iron chelators (Zygosids), first initiated at the Hebrew University of Jerusalem, Israel (HUJI), acting via the novel mechanism, based on a sequestration of the labile redox-active iron and its substitution by zinc or gallium. The mode of action of Zygosids is based on the higher affinity of the metal-binding moiety of the complex to Fe3+ in comparison to already bound ion, leading to rapid release of the ion of another metal and chelation of Fe3+. Concomitantly, zinc ion, released by the complex, is known for its antidiabetic and anti-inflammatory role. The therapeutic effect of zinc-desferrioxamine (Zygosid-50) and gallium-desferrioxamine, was tested on fat sand rat (Psammomys obesus) model of diet-induced T2DM and on Leprdb transgenic diabetic mice. Zygosids demonstrated an ability to noticeably reduce blood glucose and insulin levels and improve the lipid profile. Moreover, an ability to mitigate insulin resistance by >90% was shown on the sand rat model. In addition, a potent anti-inflammatory effect, expressed as a diminishment of the proinflammatory cytokines in tissue levels, was demonstrated. Zygosids demonstrated robust therapeutic efficacy in treatment of T2DM. Importantly, no adverse effects were detected, in all the experiments, indicating high safety profile.

Purification, chemical characterization and evaluation of the antioxidant potential of carvacrol from Thymus vulgaris

This work focuses on the purification, chemical characterization and evaluation of the antioxidant activity of carvacrol in order to determine its contribution in the high antioxidant potential of Thymus vulgaris essential oil (TEO). Firstly, 68% of carvacrol was purified from TEO using chromatography on silica gel column and then chemically characterized using spectroscopic techniques (IR, MS and 1H and 13C NMR). In vitro, the antioxidant activity has been determined using DPPH, ABTS•+ and iron chelating assays. All assays proved the strong radical scavenging and reducing power of carvacrol. In vivo, antioxidant capacity towards stressed Saccharomyces cerevisiae cells was investigated by evaluating cell viability, antioxidant enzymes’ activity, the level of lipid peroxidation (LPO) as well as the activity of succinate dehydrogenase (SDH). Using carvacrol in a dose dependent manner (6.25-25 μg/mL), cell viability was outstandingly improved by 34.5-55% compared to stressed cells. Antioxidant enzymes (CAT, SOD, GR) activities were also brought back to values comparable to control cells along with lower LPO (0.81±0.07 nmol/mg) and SDH (1.15± 0.07 μmol/min/mg of protein) at 25 μg/mL. These findings suggest that the powerful antioxidant properties of TEO found in our previous study were mainly associated to its main component (carvacrol) that showed higher antioxidant activity compared to the other components. Therefore, carvacrol can be of a great use as a pharmacological agent against damages related to oxidative stress.

Synthesis, Antioxidant and Antituberculosis Evaluation of Eugenol Derivatives from Mannich Condensation

AbstractMannich bases are interesting class of molecules thanks to their various pharmacological properties. This paper presents the synthesis and characterization of eugenol derivatives following Mannich condensation. The in vitro antituberculosis activity of the synthesized derivatives was evaluated by the Resazurin microtiter assay (REMA). The 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging and ferrous cation (FeCl2) chelating tests were used to estimate the antioxidant capacity. All eugenol Mannich bases inhibited the Mycobacterium tuberculosis (Mtb) H37Rv growing. Those of 2‐dimethylaminomethyl‐6‐methoxy‐4‐propenylphenol (1) and 2‐methoxy‐4‐propenyl‐6‐pyrrolidinylmethylphenol (4) were the most active at 10 μg/mL. Additionally, significant antioxidant profile was exhibited by the synthesized derivatives, especially for 2‐dicyclohexylaminomethyl‐6‐methoxy‐4‐propenylphenol (5) that showed an antiradical activity of EC50=20 μg/mL, twice as strong as that of eugenol precursor, and for 2‐methoxy‐6‐methylpiperazinylmethyl‐4‐propenylphenol (3) and compound 4, which were promising iron chelators with EC50 of 0.016 and 0.018 mg/mL, respectively, better than EDTA standard. The molecular docking experiments on two different antituberculosis receptors showed excellent binding affinity of compounds 4 and 5 into the active site of pantothenate kinase (PanK, type I), suggesting PanK as potential molecular target. These encouraging findings showed the importance of Mannich reaction for the development of antitubercular candidates and the improvement of natural products bioactivity.

Slowly progressive cell death induced by GPx4-deficiency occurs via MEK1/ERK2 activation as a downstream signal after iron-independent lipid peroxidation.

Glutathione peroxidase 4 (GPx4) is an antioxidant enzyme that reduces phospholipid hydroperoxide. Studies have reported that the loss of GPx4 activity through anticancer drugs leads to ferroptosis, an iron-dependent lipid peroxidation-induced cell death. In this study, we established Tamoxifen-inducible GPx4-deficient Mouse embryonic fibroblast (MEF) cells (ETK1 cells) and found that Tamoxifen-inducible gene disruption of GPx4 induces slow cell death at ~72 h. In contrast, RSL3- or erastin-induced ferroptosis occurred quickly within 24 h. Therefore, we investigated the differences in these mechanisms between GPx4 gene disruption-induced cell death and RSL3- or erastin-induced ferroptosis. We found that GPx4-deficiency induced lipid peroxidation at 24 h in Tamoxifen-treated ETK1 cells, which was not suppressed by iron chelators, although lipid peroxidation in RSL3- or erastin-treated cells induced ferroptosis that was inhibited by iron chelators. We revealed that GPx4-deficient cell death was MEK1-dependent but RSL3- or erastin-induced ferroptosis was not, although MEK1/2 inhibitors suppressed both GPx4-deficient cell death and RSL3- or erastin-induced ferroptosis. In GPx4-deficient cell death, the phosphorylation of MEK1/2 and ERK2 was observed 39 h after lipid peroxidation, but ERK1 was not phosphorylated. Selective inhibitors of ERK2 inhibited GPx4-deficient cell death but not in RSL3- or erastin-induced cell death. These findings suggest that iron-independent lipid peroxidation due to GPx4 disruption induced cell death via the activation of MEK1/ERK2 as a downstream signal of lipid peroxidation in Tamoxifen-treated ETK1 cells. This indicates that GPx4 gene disruption induces slow cell death and involves a different pathway from RSL3- and erastin-induced ferroptosis in ETK1 cells.

Curcumin-polydopamine nanoparticles alleviate ferroptosis by iron chelation and inhibition of oxidative stress damage.

Ferroptosis, characterized by elevated iron levels and lipid peroxidation (LPO), is a recently identified regulatory mechanism of cell death. Its substantial involvement in ischemic tissue injury, neurodegenerative disorders, and cancer positions ferroptosis inhibition as a promising strategy for managing these diverse diseases. In this study, we introduce curcumin-polydopamine nanoparticles (Cur-PDA NPs) as an innovative ferroptosis inhibitor. Cur-PDA NPs demonstrate remarkable efficacy in chelating both Fe2+ and Fe3+in vitro along with scavenging free radicals. Cur-PDA NPs were found to efficiently mitigate reactive oxygen species, reduce Fe2+ accumulation, suppress LPO, and rejuvenate mitochondrial function in PC12 cells. Thus, these NPs can act as potent therapeutic agents against ferroptosis, primarily via iron chelation and reduction of oxidative stress.