Understanding of ROS-Inducing Strategy in Anticancer Therapy

Navigating the redox landscape: reactive oxygen species in regulation of cell cycle

Objectives: To advance our knowledge of disease mechanisms and therapeutic options, understanding cell cycle regulation is critical. Recent research has highlighted the importance of reactive oxygen species (ROS) in cell cycle regulation. Although excessive ROS levels can lead to age-related pathologies, ROS also play an essential role in normal cellular functions. Many cell cycle regulatory proteins are affected by their redox status, but the precise mechanisms and conditions under which ROS promote or inhibit cell proliferation are not fully understood.Methods: This review presents data from the scientific literature and publicly available databases on changes in redox state during the cell cycle and their effects on key regulatory proteins.Results: We identified redox-sensitive targets within the cell cycle machinery and analysed different effects of ROS (type, concentration, duration of exposure) on cell cycle phases. For example, moderate levels of ROS can promote cell proliferation by activating signalling pathways involved in cell cycle progression, whereas excessive ROS levels can induce DNA damage and trigger cell cycle arrest or cell death.Discussion: Our findings encourage future research focused on identifying redox-sensitive targets in the cell cycle machinery, potentially leading to new treatments for diseases with dysregulated cell proliferation.

BM7, a derivative of benzofuran, effectively fights cancer by promoting cancer cell apoptosis and impacting IL-6 levels

The BM7 compound, a bromo derivative of methyl 6-acetyl-5-hydroxy-2-methyl-1-benzofuran-3-carboxylate, was previously identified as cytotoxic to human leukaemia cells (K562 and HL60) and human cervical cancer (HeLa), while showing no toxicity to non-cancerous primary endothelial cells (HUVEC). In this study, we present the first demonstration of BM7's anticancer efficacy in vivo using a mouse chronic myeloid leukaemia xenograft model. Administered intraperitoneally in a mixture of 10% Solutol HS 15/10% ethanol, BM7 exhibited no visible toxicity and significantly reduced tumor weight, comparable to standard drugs imatinib and hydroxyurea. Further supporting its anticancer potential, a multi-model in vitro study involving seven human cancer cell lines revealed the most promising responses in colon cancer (SW480, SW620, HCT116), liver cancer (HEPG2), and breast adenocarcinoma (MDA-MB-231) cells. BM7 demonstrated multifaceted anticancer mechanisms, inducing apoptosis while elevating reactive oxygen species (ROS) levels and suppressing interleukin-6 (IL-6) release in these cell lines. These findings position BM7 as a candidate of significant interest for cancer therapy. Its ability to not only induce apoptosis but also modulate cellular processes such as ROS levels and immune responses, specifically IL-6 suppression, makes BM7 a versatile and promising agent for further exploration in the realm of cancer treatment.

Fucoidan based polymeric nanoparticles encapsulating epirubicin: A novel and effective chemotherapeutic formulation against colorectal cancer

Colorectal cancer (CRC) is one of the most common and challenging malignancy that needs some effective and safer chemotherapeutic agents for the treatment. In this study, anticancer agent epirubicin (Epi) was loaded in polymeric polyethylene glycol-polylactic acid-nanoparticles (mPEG-PLA-NPs) coated with a marine anti-cancer non-toxic polysaccharide fucoidan (FC), to achieve a synergistic activity against CRC. The characterization of the NPs revealed that they were spherical, monodispersed, stable, with a negative zeta potential, and exhibited good biocompatibility and controlled release. In vitro anti-cancer activity of the NPs on HCT116 cell line was found to be promising, and corroborated well with in vivo studies involving BALB/C mice injected with C26 murine cancer cells. The outcome of MTT assay demonstrated that IC50 value of free Epi was 3.72 µM, and that of non-coated and coated Epi nano-formulations was 33.67 and 10.19 µM, respectively. Higher tumor regression, better survival and reduced off-side cardiotoxicity were observed when this novel NPs formulation was used to treat tumor-bearing mice. Free FC and Epi treated mice showed 37.73 % and 61.49 % regression in tumor size, whereas there was 79.76 % and 90.34 % tumor regression in mice treated with non-coated Epi NPs and coated Epi NPs, respectively. Therefore, mPEG-PLA-FC-Epi-NPs hold a potential to be used as an effective chemotherapeutic formulation against CRC, since it exhibited better efficacy and lower toxicity.

Photodynamic Therapy: A Novel Approach for Head and Neck Cancer Treatment with Focusing on Oral Cavity

Oral cancers, specifically oral squamous cell carcinoma (OSCC), pose a significant global health challenge, with high incidence and mortality rates. Conventional treatments such as surgery, radiotherapy, and chemotherapy have limited effectiveness and can result in adverse reactions. However, as an alternative, photodynamic therapy (PDT) has emerged as a promising option for treating oral cancers. PDT involves using photosensitizing agents in conjunction with specific light to target and destroy cancer cells selectively. The photosensitizers accumulate in the cancer cells and generate reactive oxygen species (ROS) upon exposure to the activating light, leading to cellular damage and ultimately cell death. PDT offers several advantages, including its non-invasive nature, absence of known long-term side effects when administered correctly, and cost-effectiveness. It can be employed as a primary treatment for early-stage oral cancers or in combination with other therapies for more advanced cases. Nonetheless, it is important to note that PDT is most effective for superficial or localized cancers and may not be suitable for larger or deeply infiltrating tumors. Light sensitivity and temporary side effects may occur but can be managed with appropriate care. Ongoing research endeavors aim to expand the applications of PDT and develop novel photosensitizers to further enhance its efficacy in oral cancer treatment. This review aims to evaluate the effectiveness of PDT in treating oral cancers by analyzing a combination of preclinical and clinical studies.

Targeting hematological malignancies with isoxazole derivatives

Compounds with a heterocyclic isoxazole ring are well known for their diverse biologic activities encompassing antimicrobial, antipsychotic, immunosuppressive, antidiabetic and anticancer effects. Recent studies on hematological malignancies have also shown that some of the isoxazole-derived compounds feature encouraging cancer selectivity, low toxicity to normal cells and ability to overcome cancer drug resistance of conventional treatments. These characteristics are particularly promising because patients with hematological malignancies face poor clinical outcomes caused by cancer drug resistance or relapse of the disease. This review summarizes the knowledge on isoxazole-derived compounds toward hematological malignancies and provides clues on their mechanism(s) of action (apoptosis, cell cycle arrest, ROS production) and putative pharmacological targets (c-Myc, BET, ATR, FLT3, HSP90, CARM1, tubulin, PD-1/PD-L1, HDACs) wherever known.

Thymoquinone, artemisinin, and thymol attenuate proliferation of lung cancer cells as Sphingosine kinase 1 inhibitors

Sphingosine-1-phosphate (S1P) formed via catalytic actions of sphingosine kinase 1 (SphK1) behaves as a pro-survival substance and activates downstream target molecules associated with various pathologies, including initiation, inflammation, and progression of cancer. Here, we aimed to investigate the SphK1 inhibitory potentials of thymoquinone (TQ), Artemisinin (AR), and Thymol (TM) for the therapeutic management of lung cancer. We implemented docking, molecular dynamics (MD) simulations, enzyme inhibition assay, and fluorescence measurement studies to estimate binding affinity and SphK1 inhibitory potential of TQ, AR, and TM. We further investigated the anti-cancer potential of these compounds on non-small cell lung cancer (NSCLC) cell lines (H1299 and A549), followed by estimation of mitochondrial ROS, mitochondrial membrane potential depolarization, and cleavage of DNA by comet assay. Enzyme activity and fluorescence binding studies suggest that TQ, AR, and TM significantly inhibit the activity of SphK1 with IC50 values of 35.52 µM, 42.81 µM, and 53.68 µM, respectively, and have an excellent binding affinity. TQ shows cytotoxic effect and anti-proliferative potentials on H1299 and A549 with an IC50 value of 27.96 µM and 54.43 µM, respectively. Detection of mitochondrial ROS and mitochondrial membrane potential depolarization shows promising TQ-induced oxidative stress on H1299 and A549 cell lines. Comet assay shows promising TQ-induced oxidative DNA damage. In conclusion, TQ, AR, and TM act as potential inhibitors for SphK1, with a strong binding affinity. In addition, the cytotoxicity of TQ is linked to oxidative stress due to mitochondrial ROS generation. Overall, our study suggests that TQ is a promising inhibitor of SphK1 targeting lung cancer therapy.

Chemotherapeutic Potential of Chlorambucil-Platinum(IV) Prodrugs against Cisplatin-Resistant Colorectal Cancer Cells

Chlorambucil-platinum(IV) prodrugs exhibit multi-mechanistic chemotherapeutic activity with promising anticancer potential. The platinum(II) precursors of the prodrugs have been previously found to induce changes in the microtubule cytoskeleton, specifically actin and tubulin of HT29 colon cells, while chlorambucil alkylates the DNA. These prodrugs demonstrate significant anticancer activity in 2D cell and 3D spheroid viability assays. A notable production of reactive oxygen species has been observed in HT29 cells 72 h post treatment with prodrugs of this type, while the mitochondrial membrane potential was substantially reduced. The cellular uptake of the chlorambucil-platinum(IV) prodrugs, assessed by ICP-MS, confirmed that active transport was the primary uptake mechanism, with platinum localisation identified primarily in the cytoskeletal fraction. Apoptosis and necrosis were observed at 72 h of treatment as demonstrated by Annexin V-FITC/PI assay using flow cytometry. Immunofluorescence measured via confocal microscopy showed significant changes in actin and tubulin intensity and in architecture. Western blot analysis of intrinsic and extrinsic pathway apoptotic markers, microtubule cytoskeleton markers, cell proliferation markers, as well as autophagy markers were studied post 72 h of treatment. The proteomic profile was also studied with a total of 1859 HT29 proteins quantified by mass spectroscopy, with several dysregulated proteins. Network analysis revealed dysregulation in transcription, MAPK markers, microtubule-associated proteins and mitochondrial transport dysfunction. This study confirms that chlorambucil-platinum(IV) prodrugs are candidates with promising anticancer potential that act as multi-mechanistic chemotherapeutics.

Isopentyl-Deoxynboquinone Induces Mitochondrial Dysfunction and G2/M Phase Cell Cycle Arrest to Selectively Kill NQO1-Positive Pancreatic Cancer Cells

Aims: Pancreatic cancer is among the top five leading causes of cancer-related deaths worldwide, with poor overall survival rates. Current therapies for pancreatic cancer lack tumor specificity, resulting in harmful effects on normal tissues. Therefore, developing tumor-specific agents for the treatment of pancreatic cancer is critical. NAD(P)H:quinone oxidoreductase 1 (NQO1), highly expressed in pancreatic cancers but not in associated normal tissues, makes NQO1 bioactivatable drugs a potential therapy for selectively killing NQO1-positive cancer cells. Our previous studies have revealed that the novel NQO1 bioactivatable drug deoxynyboquinone (DNQ) is 10-fold more potent than the prototypic NQO1 bioactivatable drug β-lapachone in killing of NQO1-positive cancer cells. However, DNQ treatment results in high-grade methemoglobinemia, a significant side effect that limits clinical development. Results: Here, we report for the first time on a DNQ derivative, isopentyl-deoxynboquinone (IP-DNQ), which selectively kills pancreatic ductal adenocarcinoma (PDAC) cells in an NQO1-dependent manner with equal potency to the parent DNQ. IP-DNQ evokes massive reactive oxygen species (ROS) production and oxidative DNA lesions that result in poly(ADP-ribose)polymerase-1 (PARP1) hyperactivation, mitochondrial catastrophe, and G2/M phase cell cycle arrest, leading to apoptotic and necrotic programmed cell death. Importantly, IP-DNQ treatment causes only mild methemoglobinemia in vivo, with a threefold improvement in the maximum tolerated dose (MTD) compared with DNQ, while it significantly suppresses tumor growth and extends the life span of mice in subcutaneous and orthotopic pancreatic cancer xenograft models. Innovation and Conclusion: Our study demonstrates that IP-DNQ is a promising therapy for NQO1-positive pancreatic cancers and may enhance the efficacy of other anticancer drugs. IP-DNQ represents a novel approach to treating pancreatic cancer with the potential to improve patient outcomes.

Self-assembled copper-based nanoparticles for enzyme catalysis-enhanced chemodynamic/photodynamic/antiangiogenic tritherapy against hepatocellular carcinoma

As an emerging cancer treatment strategy, reactive oxygen species-based tumor catalytic therapies face enormous challenges due to hypoxia and the overexpression of glutathione (GSH) in the tumor microenvironment. Herein, a self-assembled copper-based nanoplatform, TCCHA, was designed for enzyme-like catalysis-enhanced chemodynamic/photodynamic/antiangiogenic tritherapy against hepatocellular carcinoma. TCCHA was fabricated from Cu2+, 3,3'-dithiobis (propionohydrazide), and photosensitizer chlorine e6 via a facile one-pot self-assembly strategy, after which an aldehyde hyaluronic acid was coated, followed by loading of the antivascular drug AL3818. The obtained TCCHA nanoparticles exhibited pH/GSH dual-responsive drug release behaviors and multienzymatic activities, including Fenton, glutathione peroxidase-, and catalase-like activities. TCCHA, a redox homeostasis disruptor, promotes ⋅OH generation and GSH depletion, thus increasing the efficacy of chemodynamic therapy. TCCHA, which has catalase-like activity, can also reinforce the efficacy of photodynamic therapy by amplifying O2 production. In vivo, TCCHA efficiently inhibited tumor angiogenesis and suppressed tumor growth without apparent systemic toxicity. Overall, this study presents a facile strategy for the preparation of multienzyme-like nanoparticles, and TCCHA nanoparticles display great potential for enzyme catalysis-enhanced chemodynamic/photodynamic/antiangiogenic triple therapy against cancer.

Role of 4-Thiazolidinone-Pyrazoline/Indoline Hybrids Les-4369 and Les-3467 in BJ and A549 Cell Lines

Cancer is one of the most important problems of modern societies. Recently, studies have reported the anticancer properties of rosiglitazone related to its ability to bind peroxisome proliferator receptor γ (PPARγ), which has various effects on cancer and can inhibit cell proliferation. In this study, we investigated the effect of new 4-thiazolidinone (4-TZD) hybrids Les-4369 and Les-3467 and their effect on reactive oxygen species (ROS) production, metabolic activity, lactate dehydrogenase (LDH) release, caspase-3 activity, and gene and protein expression in human foreskin fibroblast (BJ) cells and lung adenocarcinoma (A549) cells. The ROS production and caspase-3 activity were mainly increased in the micromolar concentrations of the studied compounds in both cell lines. Les-3467 and Les-4369 increased the mRNA expression of PPARG, P53 (tumor protein P53), and ATM (ATM serine/threonine kinase) in the BJ cells, while the mRNA expression of these genes (except PPARG) was mainly decreased in the A549 cells treated with both of the tested compounds. Our results indicate a decrease in the protein expression of AhR, PPARγ, and PARP-1 in the BJ cells exposed to 1 µM Les-3467 and Les-4369. In the A549 cells, the protein expression of AhR, PPARγ, and PARP-1 increased in the treatment with 1 µM Les-3467 and Les-4369. We have also shown the PPARγ modulatory properties of Les-3467 and Les-4369. However, both compounds prove weak anticancer properties evidenced by their action at high concentrations and non-selective effects against BJ and A549 cells.

Generation of Hydrogen Peroxide in Cancer Cells: Advancing Therapeutic Approaches for Cancer Treatment

Cancer cells show altered antioxidant defense systems, dysregulated redox signaling, and increased generation of reactive oxygen species (ROS). Targeting cancer cells through ROS-mediated mechanisms has emerged as a significant therapeutic strategy due to its implications in cancer progression, survival, and resistance. Extensive research has focused on selective generation of H2O2 in cancer cells for selective cancer cell killing by employing various strategies such as metal-based prodrugs, photodynamic therapy, enzyme-based systems, nano-particle mediated approaches, chemical modulators, and combination therapies. Many of these H2O2-amplifying approaches have demonstrated promising anticancer effects and selectivity in preclinical investigations. They selectively induce cytotoxicity in cancer cells while sparing normal cells, sensitize resistant cells, and modulate the tumor microenvironment. However, challenges remain in achieving selectivity, addressing tumor heterogeneity, ensuring efficient delivery, and managing safety and toxicity. To address those issues, H2O2-generating agents have been combined with other treatments leading to optimized combination therapies. This review focuses on various chemical agents/approaches that kill cancer cells via H2O2-mediated mechanisms. Different categories of compounds that selectively generate H2O2 in cancer cells are summarized, their underlying mechanisms and function are elucidated, preclinical and clinical studies as well as recent advancements are discussed, and their prospects as targeted therapeutic agents and their therapeutic utility in combination with other treatments are explored. By understanding the potential of these compounds, researchers can pave the way for the development of effective and personalized cancer treatments.

Facile Fabrication of Titanium Carbide (Ti3C2)-Bismuth Vanadate (BiVO4) Nano-Coupled Oxides for Anti-cancer Activity

Background MXene is a newly discovered substance consisting of 2D transition metal carbides or nitrides, produced through the disintegration and etching of aluminum layers. It possesses numerous properties, including a high surface area, conductivity, strength, stiffness, negative zeta potential, and excellent volumetric capacitance. MXene is utilized in detecting anti-cancer medicine, while bismuth vanadate (BiVO4) is synthesized to form an optimized material for anti-cancer activity applications. BiVO4 exhibits visible light absorption, strong chemical stability, and non-toxic properties. However, when loaded onto target stem cells, it can cause skin and respiratory irritation. Aim This study aimed to evaluate the facile fabrication of titanium carbide (Ti3C2)-BiVO4 nanomaterials coupled with oxides for anti-cancer activity. Moreover, it aimed to create Ti3C2-BiVO4 nanomaterials in combination with oxides using X-ray diffraction (XRD) and scanning electron microscopy (SEM) to assess their potential as efficient and targeted anti-cancer agents. Methods and materials To prepare the 2D Ti3C2 MXene, 2.5 g of titanium aluminum carbide (Ti3AlC2) powder was dissolved in 60 mL of a 40% hydrofluoric acid (HF) solution in a polytetrafluoroethylene(PTFE) container. The etching process was made more efficient and completed in 24 hours by using a magnetic stirring system to keep the mixture stirred and heated continuously. The centrifugation was performed at 4000 rpm for five minutes. Subsequently, deionized water was used to wash the solution many times until its pH reached around 7. The appropriate Ti3C2 powder was made by vacuum drying the acquired sediment at 80°C for 24 hours. Monoclinic BiVO4 samples were synthesized via a hydrothermal method. Typically, 10 mmol of Bi(NO3)3.5H2O was dissolved in 100 mL of a 2 mol/L HNO3 solution and stirred uniformly. Subsequently, 10 mmol of ammonium metavanadate (NH4VO3) was added to the mixed solution. After being stirred for one hour, the mixture was transferred into a 100 mL sealed Teflon-lined stainless steel autoclave at 180°C for 16 hours. After cooling to room temperature, the sediment was washed three times with deionized water, ethanol, and acetone, respectively. Finally, the suspension was dried at 80°C, followed by calcination at 450°C for three hours to obtain BiVO4. Ti3C2-BiVO4 heterostructures were prepared by surface modification Ti3C2 using BiVO4 suspensions by a simple, cost-effective approach. Results Ti3C2 nanosheets were observed with BiVO4 particles, and the high crystalline nature of the compound was confirmed after XRD analysis and energy-dispersive spectroscopy (EDS) analysis. The compound was found to be pure without any impurities and exhibited anti-cancer activity. Conclusion The XRD, field emission scanning electron microscopy(FESEM), and EDS investigations provide an in-depth analysis of the structural, morphological, and compositional characteristics of Ti3C2-BiVO4 sheets. The XRD analysis proves the successful combination of different materials and the presence of crystalline phases. The FESEM imaging technique exposes the shape and arrangement of particles in sheets, while the EDS analysis verifies the elemental composition and uniform distribution. These investigations show that Ti3C2-BiVO4 composites have been successfully synthesized, indicating their potential for use in anti-cancer applications.

Strobilurin X acts as an anticancer drug by inhibiting protein synthesis and suppressing mitochondrial respiratory chain activity

PURPOSE

Strobilurins act as antifungal agents by inhibiting the mitochondrial respiratory chain. The cytotoxic activity of strobilurins, focusing on its anticancer activities, has been reported. However, the mechanisms involved in these activities remain unclear.

METHODS

The cytotoxic effects of strobilurin X isolated from the mycelium of Mucidula. venosolamellata were examined in human cancer cell lines (A549 and HeLa) and normal fibroblasts (WI-38).

RESULTS

Strobilurin X significantly decreased the viability of A549 and HeLa cells compared to that in the WI-38 cells after 48 h of exposure. The EC50 values for cytotoxicity in the A549, HeLa, and WI-38 cells were 3.4, 5.4, and 16.8 μg/mL, respectively. Strobilurin X inhibited the mitochondrial respiratory chain and enhanced the release of lactate in the A549 cells. The IC50 value of strobilurin X against the mitochondrial respiratory chain complex III activity was 139.8 ng/mL. The cytotoxicity induced by strobilurin X was not completely rescued after adding uridine, methyl pyruvate, or N-acetyl cysteine. Furthermore, pharmacological approaches demonstrated that strobilurin X failed to modulate the mitogen-activated protein kinase family and phosphoinositide 3-kinase-Akt pathways; alternatively, it suppressed protein synthesis independent of uridine.

CONCLUSION

Strobilurin X induced cytotoxicity by blocking the mitochondrial respiratory chain and suppressing protein synthesis. These findings may aid in the development of novel anticancer drugs using strobilurins.

Superparamagnetic Iron Oxide Nanoparticles Reprogram the Tumor Microenvironment and Reduce Lung Cancer Regrowth after Crizotinib Treatment

ALK-positive NSCLC patients demonstrate initial responses to ALK tyrosine kinase inhibitor (TKI) treatments, but eventually develop resistance, causing rapid tumor relapse and poor survival rates. Growing evidence suggests that the combination of drug and immune therapies greatly improves patient survival; however, due to the low immunogenicity of the tumors, ALK-positive patients do not respond to currently available immunotherapies. Tumor-associated macrophages (TAMs) play a crucial role in facilitating lung cancer growth by suppressing tumoricidal immune activation and absorbing chemotherapeutics. However, they can also be programmed toward a pro-inflammatory tumor suppressive phenotype, which represents a highly active area of therapy development. Iron loading of TAMs can achieve such reprogramming correlating with an improved prognosis in lung cancer patients. We previously showed that superparamagnetic iron oxide nanoparticles containing core-cross-linked polymer micelles (SPION-CCPMs) target macrophages and stimulate pro-inflammatory activation. Here, we show that SPION-CCPMs stimulate TAMs to secrete reactive nitrogen species and cytokines that exert tumoricidal activity. We further show that SPION-CCPMs reshape the immunosuppressive Eml4-Alk lung tumor microenvironment (TME) toward a cytotoxic profile hallmarked by the recruitment of CD8+ T cells, suggesting a multifactorial benefit of SPION-CCPM application. When intratracheally instilled into lung cancer-bearing mice, SPION-CCPMs delay tumor growth and, after first line therapy with a TKI, halt the regrowth of relapsing tumors. These findings identify SPIONs-CCPMs as an adjuvant therapy, which remodels the TME, resulting in a delay in the appearance of resistant tumors.

Anticancer properties and metabolomic profiling of Shorea roxburghii extracts toward gastrointestinal cancer cell lines

BACKGROUND

Gastrointestinal cancer (GIC) ranks as the highest cause of cancer-related deaths globally. GIC patients are often diagnosed at advanced stages, limiting effective treatment options. Chemotherapy, the common GIC recommendation, has significant disadvantages such as toxicity and adverse effects. Natural products contain substances with diverse pharmacological characteristics that promise for use in cancer therapeutics. In this study, the flower of renowned Asian medicinal plant, Shorea roxburghii was collected and extracted to investigate its phytochemical contents, antioxidant, and anticancer properties on GIC cells.

METHODS

The phytochemical contents of Shorea roxburghii extract were assessed using suitable methods. Phenolic content was determined through the Folin-Ciocalteu method, while flavonoids were quantified using the aluminum chloride (AlCl3) method. Antioxidant activity was evaluated using the FRAP and DPPH assays. Cytotoxicity was assessed in GIC cell lines via the MTT assay. Additionally, intracellular ROS levels and apoptosis were examined through flow cytometry techniques. The correlation between GIC cell viability and phytochemicals, 1H-NMR analysis was conducted.

RESULTS

Among the four different solvent extracts, ethyl acetate extract had the highest phenolic and flavonoid contents. Water extract exhibited the strongest reducing power and DPPH scavenging activity following by ethyl acetate. Interestingly, ethyl acetate extract demonstrated the highest inhibitory activity against three GIC cell lines (KKU-213B, HepG2, AGS) with IC50 values of 91.60 µg/ml, 39.38 µg/ml, and 35.59 µg/ml, while showing less toxicity to normal fibroblast cells. Ethyl acetate extract induced reactive oxygen species and apoptosis in GIC cell lines by downregulating anti-apoptotic protein Bcl-2. Metabolic profiling-based screening revealed a positive association between reduced GIC cell viability and phytochemicals like cinnamic acid and its derivatives, ferulic acid and coumaric acid.

CONCLUSIONS

This study highlights the potential of natural compounds in Shorea roxburghii in the development of more effective and safer anticancer agents as options for GIC as well as shedding light on new avenues for cancer treatment.

Enrichment and Evaluation of Antitumor Properties of Total Flavonoids from Juglans mandshurica Maxim

Flavonoids are important secondary metabolites found in Juglans mandshurica Maxim., which is a precious reservoir of bioactive substances in China. To explore the antitumor actions of flavonoids (JMFs) from the waste branches of J. mandshurica, the following optimized purification parameters of JMFs by macroporous resins were first obtained. The loading concentration, flow rate, and loading volume of raw flavonoid extracts were 1.4 mg/mL, 2.4 BV/h, and 5 BV, respectively, and for desorption, 60% ethanol (4 BV) was selected to elute JMFs-loaded AB-8 resin at a flow rate of 2.4 BV/h. This adsorption behavior can be explained by the pseudo-second-order kinetic model and Langmuir isotherm model. Subsequently, JMFs were identified using Fourier transform infrared combined with high-performance liquid chromatography and tandem mass spectrometry, and a total of 156 flavonoids were identified. Furthermore, the inhibitory potential of JMFs on the proliferation, migration, and invasion of HepG2 cells was demonstrated. The results also show that exposure to JMFs induced apoptotic cell death, which might be associated with extrinsic and intrinsic pathways. Additionally, flow cytometry detection found that JMFs exposure triggered S phase arrest and the generation of reactive oxygen species in HepG2 cells. These findings suggest that the JMFs purified in this study represent great potential for the treatment of liver cancer.

Using C. elegans as a model for neurodegenerative diseases: Methodology and evaluation

Caenorhabditis elegans is a nematode that has been used as an animal model for almost 50years. It has primitive and simple tissues and organs, making it an ideal model for studying neurological pathways involved in neurodegenerative diseases like Alzheimer's disease (AD) and Parkinson's disease (PD). C. elegans has conserved neurological pathways and is able to mimic human diseases, providing valuable insights into the human disease phenotype. This methodological review presents current approaches to generate neurodegenerative-like models of AD and PD in C. elegans, and evaluates the experiments commonly used to validate the diseases. These experimental approaches include assessing survival, fertility, mobility, electropharyngeogram assays, confocal mitochondrial imaging, RNA extraction for qRT-PCR or RT-PCR, and rate of defecation. This review also summarizes the current knowledge acquired on AD and PD using the aforementioned experimental approaches. Additionally, gaps in knowledge and future directions for research are also discussed in the review.

Piperlongumine inhibits antioxidant enzymes, increases ROS levels, induces DNA damage and G2/M cell cycle arrest in breast cell lines

Piperlongumine (PLN) is a biologically active alkaloid/amide derived from Piper longum, with known promising anticancer activity. The aim of this study was to compare the antiproliferative activity of PLN in human breast MCF-7 adenocarcinoma cell line with effects in HB4a normal mammary epithelial non-tumor cell line. The parameters examined were cell growth, viability, reactive oxygen species (ROS) levels and DNA damage, as well as the effects on the modulating targets responsible through regulation of these pathways. PLN increased ROS levels and expression of the SOD1 antioxidant enzyme. PLN inhibited the expression of the antioxidant enzymes catalase, TRx1, and PRx2. The ability of PLN to inhibit antioxidant enzyme expression was associated with the oxidative stress response. PLN induced genotoxicity in both cell lines and upregulated the levels of GADD45A mRNA and p21 protein. The DNA damage response ATR protein was downregulated in both cell lines and contributed to an enhanced PLN genotoxicity. In HB4a cells, Chk1 protein, and mRNA levels were also decreased. In response to elevated ROS levels and DNA damage induction, the cells were arrested at the G2/M phase, probably in an attempt to promote cell survival. Although cell viability was reduced in both cell lines, only HB4a cells underwent apoptotic cell death, whereas other types of cellular death may be involved in MCF-7 cells. Taken together, these data provide insight into the anticancer mechanisms attributed to PLN effects, which acts as an inhibitor of DNA damage response (DDR) proteins and antioxidant enzymes.

Ethanolic extract from leaves of tithonia diversifolia induces apoptosis in HCT-116 cells through oxidative stress

Tithonia diversifolia is a perennial bushy plant found in South America with significant ethnopharmacological importance as an antimalarial, antidiabetic, antibacterial, and anticancer agent. The aim of the present study was to determine the cytotoxicity of the ethanolic extract from leaves of T. diversifolia (TdE) on human cancer cell lines (HCT-116, SNB-19, NCIH-460 and MCF-7), as well as the mechanism of action involved in cell death and cellular modulation of oxidative stress. The TdE exhibited significant activity with IC50 values ranging from 7.12 to 38.41 μg/ml, with HCT-116 being the most sensitive cell line. Subsequent experiments were conducted with HCT-116 cell line. TdE decreased the number of viable cells, followed by induction of apoptotic events, increase in mitochondrial membrane permeabilization, and enhanced G2/M phase of the cell cycle. Pro-oxidative effects including elevated acidic vesicular organelle formation, lipid peroxidation, and nitric oxide by-products, as well as reduced levels of intracellular glutathione and reactive oxygen species production were also observed following incubation with TdE, which may lead to DNA damage followed by apoptotic cell death. These results demonstrate the potential of TdE ethanolic leaf extraction for biological activity and enhance the importance of continuing to study natural sources of plants for the development of anticancer agents.

Curcuma longa extract inhibits migration by reducing MMP-9 and Rac-1 expression in highly metastatic breast cancer cells

Background and purpose

Highly metastatic breast cancer is a population of cancer cells that has metastasized to other organs in the body leading to apoptosis resistance. It was reported that MDAMB-231 cells contain lower levels of reactive oxygen species associated with metastatic capability. Curcuma longa (CL) possesses cytotoxic effects in several cancer cells including metastatic breast cancer cells. This study aimed to investigate the effect of CL-inhibited cell migration in highly metastatic breast cancer MDAMB-231 cells.

Experimental approach

CL was extracted under maceration with methanol. The cytotoxic effect on single and combination treatment of CL was assessed through the MTT assay. Migration analysis was evaluated using scratch wound healing assay, MMP-9 expression by gelatine zymography, Rac-1, and MMP-9 gene expression using Real-Time Quantitative Reverse transcription polymerase chain reaction (qRT-PCR). The apoptosis induction was analyzed through Bax gene expression and Bcl-2 protein expression.

Findings/Results

We found that CL inhibits the growth of MDAMB-231 cells, induces Bax gene expression, and suppresses Bcl-2 expression in a dose-dependent manner. Moreover, cancer cell migration was suppressed by the presence of CL. qRT-PCR and gelatine zymography assay showed that CL downregulates Rac-1 and MMP-9 gene expression.

Conclusion and implications

CL could inhibit the growth and migration of highly metastatic breast cancer cells by reducing the Rac-1 gene expression and regulating apoptosis protein expression.

Gaillardin exerts potent antileukemic effects on HL-60 cells and intensifies arsenic trioxide cytotoxicity: Providing new insight into sesquiterpene lactones in leukaemia treatment

The use of all-trans retinoic acid and arsenic trioxide resulted in favourable therapeutic responses in standard-risk acute promyelocytic leukaemia (APL) patients. However, resistance to these agents has made treating the high-risk subgroup more problematic, and possible side effects limit their clinical dosages. Numerous studies have proven the cytotoxic properties of Gaillardin, one of the Inula oculus-christi-derived sesquiterpene lactones. Due to the adverse effects of arsenic trioxide on the high-risk subgroup of APL patients, we aimed to assess the cytotoxic effect of Gaillardin on HL-60 cells as a single or combined-form approach. The results of the trypan blue and MTT assays outlined the potent cytotoxic properties of Gaillardin. The flow cytometric analysis and the mRNA expression levels revealed that Gaillardin attenuated the proliferative capacity of HL-60 cells through cell cycle arrest and induced apoptosis via reactive oxygen species generation. Moreover, the results of synergistic experiments indicated that this sesquiterpene lactone sensitizes HL-60 cells to the cytotoxic effects of arsenic trioxide. Taken together, the findings of the present investigation highlighted the antileukemic characteristics of Gaillardin by inducing G1 cell cycle arrest and triggering apoptosis. Gaillardin acts as an antileukemic metabolite against HL-60 cells and this study provides new insight into treating APL patients, especially in the high-risk subgroup.

Anti-proliferative, Pro-apoptotic, and Chemosensitizing Potential of 3-Acetyl-11-keto-β-boswellic Acid (AKBA) Against Prostate Cancer Cells

Prostate cancer incidences are rising worldwide at an alarming rate. Drug resistance and relapse are two major challenges in the treatment of prostate cancer. Therefore, new multimodal, safe, and effective therapeutic agents are urgently required which could effectively mitigate the menace of tumor recurrence and chemo-resistance. Plant-derived products are increasingly being utilized due to their antioxidant, antibacterial, and anti-tumor potential. In the current study, 3-acetyl-11-keto-β-boswellic acid, a triterpenoid isolated from plant Boswellia, was utilized to ascertain its chemotherapeutic potential against human prostate cancer cells. Various in vitro assays including cell viability, nuclear staining, mitochondria potential, reactive oxygen species (ROS) generation, and quantification of apoptosis, were performed for the evaluation of the cytotoxic potential of AKBA. We observed that AKBA (10-50 µM) dose-dependently suppressed cell proliferation and caused programmed cell death in PC3 cells via both intrinsic and extrinsic pathway. Intriguingly, AKBA was also found to chemosensitize PC3 cells in synergistic combination with doxorubicin. To the best of our knowledge, this is the first study to document the synergistic chemosensitizing impact of AKBA when combined with doxorubicin in prostate cancer cells.This showcases the potential of AKBA in combinatorial therapy or adjuvant therapy for the management of prostate cancer. In sum, our results suggested that AKBA is a promising drug-like molecule against prostate cancer. Our investigation introduces a novel perspective, elucidating a previously unexplored dimension, and uncovering a compelling chemosensitizing phenomenon along with a strong synergistic effect arising from the concurrent application of these two agents.

Demethoxymurrapanine, an indole-naphthoquinone alkaloid, inhibits the proliferation of oral cancer cells without major side effects on normal cells

Antioral cancer drugs need a greater antiproliferative impact on cancer than on normal cells. Demethoxymurrapanine (DEMU) inhibits proliferation in several cancer cells, but an in-depth investigation was necessary. This study evaluated the proliferation-modulating effects of DEMU, focusing on oral cancer and normal cells. DEMU (0, 2, 3, and 4 μg/mL) at 48 h treatments inhibited the proliferation of oral cancer cells (the cell viability (%) for Ca9-22 cells was 100.0 ± 2.2, 75.4 ± 5.6, 26.0 ± 3.8, and 15.4 ± 1.4, and for CAL 27 cells was 100.0 ± 9.4, 77.2 ± 5.9, 57.4 ± 10.7, and 27.1 ± 1.1) more strongly than that of normal cells (the cell viability (%) for S-G cells was 100.0 ± 6.6, 91.0 ± 4.6, 95.0 ± 2.6, and 95.8 ± 5.5), although this was blocked by the antioxidant N-acetylcysteine. The presence of oxidative stress was evidenced by the increase of reactive oxygen species and mitochondrial superoxide and the downregulation of the cellular antioxidant glutathione in oral cancer cells, but these changes were minor in normal cells. DEMU also caused greater induction of the subG1 phase, extrinsic and intrinsic apoptosis (annexin V and caspases 3, 8, and 9), and DNA damage (γH2AX and 8-hydroxy-2-deoxyguanosine) in oral cancer than in normal cells. N-acetylcysteine attenuated all these DEMU-induced changes. Together, these data demonstrate the preferential antiproliferative function of DEMU in oral cancer cells, with the preferential induction of oxidative stress, apoptosis, and DNA damage in these cancer cells, and low cytotoxicity toward normal cells.

The Promise of Combination Therapies with FOXM1 Inhibitors for Cancer Treatment

Forkhead box M1 (FOXM1) is a transcription factor in the forkhead (FOX) family, which is required for cellular proliferation in normal and neoplastic cells. FOXM1 is highly expressed in many different cancers, and its expression is associated with a higher tumor stage and worse patient-related outcomes. Abnormally high expression of FOXM1 in cancers compared to normal tissue makes FOXM1 an attractive target for pharmacological inhibition. FOXM1-inhibiting agents and specific FOXM1-targeted small-molecule inhibitors have been developed in the lab and some of them have shown promising efficacy and safety profiles in mouse models. While the future goal is to translate FOXM1 inhibitors to clinical trials, potential synergistic drug combinations can maximize anti-tumor efficacy while minimizing off-target side effects. Hence, we discuss the rationale and efficacy of all previously studied drug combinations with FOXM1 inhibitors for cancer therapies.

Molecular Mechanism of Natural Food Antioxidants to Regulate ROS in Treating Cancer: A Review

Cancer is the second-highest mortality rate disease worldwide, and it has been estimated that cancer will increase by up to 20 million cases yearly by 2030. There are various options of treatment for cancer, including surgery, radiotherapy, and chemotherapy. All of these options have damaging adverse effects that can reduce the patient's quality of life. Cancer itself arises from a series of mutations in normal cells that generate the ability to divide uncontrollably. This cell mutation can happen as a result of DNA damage induced by the high concentration of ROS in normal cells. High levels of reactive oxygen species (ROS) can cause oxidative stress, which can initiate cancer cell proliferation. On the other hand, the cytotoxic effect from elevated ROS levels can be utilized as anticancer therapy. Some bioactive compounds from natural foods such as fruit, vegetables, herbs, honey, and many more have been identified as a promising source of natural antioxidants that can prevent oxidative stress by regulating the level of ROS in the body. In this review, we have highlighted and discussed the benefits of various natural antioxidant compounds from natural foods that can regulate reactive oxygen species through various pathways.

Mitocurcumin utilizes oxidative stress to upregulate JNK/p38 signaling and overcomes Cytarabine resistance in acute myeloid leukemia

Acute myeloid leukemia (AML) is a type of blood cancer that is characterized by the rapid growth of abnormal myeloid cells. The goal of AML treatment is to eliminate the leukemic blasts, which is accomplished through intensive chemotherapy. Cytarabine is a key component of the standard induction chemotherapy regimen for AML. However, despite a high remission rate, 70-80% of AML patients relapse and develop resistance to Cytarabine, leading to poor clinical outcomes. Mitocurcumin (MitoC), a derivative of curcumin that enters mitochondria, leading to a drop in mitochondrial membrane potential and mitophagy induction. Further, it activates oxidative stress-mediated JNK/p38 signaling to induce apoptosis. MitoC demonstrated a preferential ability to kill leukemic cells from AML cell lines and patient-derived leukemic blasts. RNA sequencing data suggests perturbation of DNA damage response and cell proliferation pathways in MitoC-treated AML. Elevated reactive oxygen species (ROS) in MitoC-treated AML cells resulted in significant DNA damage and cell cycle arrest. Further, MitoC treatment resulted in ROS-mediated enhanced levels of p21, which leads to suppression of CHK1, RAD51, Cyclin-D and c-Myc oncoproteins, potentially contributing to Cytarabine resistance. Combinatorial treatment of MitoC and Cytarabine has shown synergism, increased apoptosis, and enhanced DNA damage. Using AML xenografts, a significant reduction of hCD45+ cells was observed in AML mice bone marrow treated with MitoC (mean 0.6%; range0.04%-3.56%) compared to control (mean 38.2%; range10.1%-78%), p = 0.03. The data suggest that MitoC exploits stress-induced leukemic oxidative environment to up-regulate JNK/p38 signaling to lead to apoptosis and can potentially overcome Cytarabine resistance via ROS/p21/CHK1 axis.

Spinosyn A exerts anti-tumorigenic effects on progesterone-sensitive ERα-positive breast cancer cells by modulating multiple signaling pathways

Breast cancer is one of the most common and deadly cancers in women worldwide. Current treatments for breast cancer have limitations, such as toxicity, resistance, and side effects. Therefore, there is a need to develop new and effective anti-cancer agents from natural sources. Spinosyn A (SPA) is a natural product derived from soil bacteria. SPA has been reported to have anti-parasitic, insecticidal, and anti-bacterial activities. However, its anti-cancer effects and mechanisms are not well understood. In this study, we investigated the effects of SPA on T47-D, estrogen receptor-positive breast cancer cells. We found that SPA inhibited cell proliferation and migration and induced apoptosis and cell cycle arrest. Flow cytometry and holographic imaging microscopy revealed that SPA activated MAPK and PI3K signaling pathways and altered cellular morphology. Finally, RNA-Seq analysis revealed that SPA treatment altered the expression of 1380 genes in T47-D cells, which were enriched in various biological processes and signaling pathways related to cell proliferation, cholesterol metabolism, growth factor activity, amino acid transport activity, extracellular matrix, PI3K-Akt signaling pathway, neuroactive ligand-receptor interaction, and PPAR signaling pathway. Our results suggest that SPA exerts multiple anti-cancer effects on T47-D cells by modulating multiple pathways and cellular processes involved in cell growth, survival, and motility. Our findings provide new insights into the molecular mechanisms of SPA action on breast cancer cells and its potential applications as a novel anti-cancer agent.

Harnessing small extracellular vesicles for pro-oxidant delivery: novel approach for drug-sensitive and resistant cancer therapy

Multidrug resistance (MDR) is an inevitable clinical problem in chemotherapy due to the activation of abundant P-glycoprotein (P-gp) that can efflux drugs. Limitations of current cancer therapy highlight the need for the development of a comprehensive cancer treatment strategy, including drug-resistant cancers. Small extracellular vesicles (sEVs) possess significant potential in surmounting drug resistance as they can effectively evade the efflux mechanism and transport small molecules directly to MDR cancer cells. One mechanism mediating MDR in cancer cells is sustaining increased levels of reactive oxygen species (ROS) and maintenance of the redox balance with antioxidants, including glutathione (GSH). Herein, we developed GSH-depleting benzoyloxy dibenzyl carbonate (B2C)-encapsulated sEVs (BsEVs), which overcome the efflux system to exert highly potent anticancer activity against human MDR ovarian cancer cells (OVCAR-8/MDR) by depleting GSH to induce oxidative stress and, in turn, apoptotic cell death in both OVCAR-8/MDR and OVCAR-8 cancer cells. BsEVs restore drug responsiveness by inhibiting ATP production through the oxidation of nicotinamide adenine dinucleotide with hydrogen (NADH) and inducing mitochondrial dysfunction, leading to the dysfunction of efflux pumps responsible for drug resistance. In vivo studies showed that BsEV treatment significantly inhibited the growth of OVCAR-8/MDR and OVCAR-8 tumors. Additionally, OVCAR-8/MDR tumors showed a trend towards a greater sensitivity to BsEVs compared to OVCAR tumors. In summary, this study demonstrates that BsEVs hold tremendous potential for cancer treatment, especially against MDR cancer cells.

Polyphenol Mediated Suppression of Hepatocellular Carcinoma (HepG2) Cell Proliferation by Clerodendrum infortunatum L. Root

OBJECTIVE

Clerodendrum infortunatum L. has long been used in traditional medicine in Sri Lanka for tumours, cancer, and certain skin diseases. The present study aimed to assess the anticancer properties of the aqueous extract of C. infortunatum L. root (AECIR) through the activation of the apoptotic pathway on hepatocellular carcinoma (HepG2) and thus give it a scientific validation. Further, the contribution of polyphenols in antioxidant activity and cell cytotoxicity was investigated.

METHODS

Powdered plant material was boiled with water (100°C) to obtained AECIR.  The DPPH assay was used to determine the antioxidant potential. The activity of AECIR on HepG2 and normal rat fibroblast (CC1) cell growth was determined using MTT assay. The morphological changes related to apoptotic pathway was examined by Ethidium Bromide/Acridine Orange (EB/AO), Rhodamine 123 (Rh123) and DNA fragmentation assay.

RESULTS

The AECIR demonstrated antioxidant potential with an EC50 of 350.2 ± 1.5 ug/mL for DPPH assay. The HO•, H2O2 and •NO free radical scavenging activity was observed with EC50 of 19.7 ± 2.3, 11.7 ± 0.1 and 273.1 ± 0.9 ug/mL, respectively. The antiproliferative effect of AECIR on HepG2 cells was observed in a time and dose dependent manner with an EC50 of 239.1 ± 1.3 μg/mL while CC1 cells showed a nontoxic effect with an EC50 1062.7 ± 3.4 μg/mL after 24hrs treatment. A significant decrease in antioxidant activity (p<0.001) and 90% HepG2 cell viability was observed with polyphenol removed AECIR compared to the polyphenol present AECIR. The EB/AO uptake, depletion of mitochondrial transmembrane potential, and DNA fragmentation assay results revealed that the apoptosis was induced by AECIR.

CONCLUSION

The obtained result of the present study demonstrates that the antioxidant potential and antiproliferative activity of AECIR is attributed to the presence of polyphenols. Furthermore, the findings provide the scientific base for anti-cancer potential of AECIR.

Combination of metformin/efavirenz/fluoxetine exhibits profound anticancer activity via a cancer cell-specific ROS amplification

The possible anticancer activity of combination (M + E + F) of metformin (M), efavirenz (E), and fluoxetine (F) was investigated in normal HDF cells and HCT116 human colon cancer cells. Metformin increased cellular FOXO3a, p-FOXO3a, AMPK, p-AMPK, and MnSOD levels in HDFs but not in HCT116 cells. Cellular ATP level was decreased only in HDFs by metformin. Metformin increased ROS level only in HCT116 cells. Transfection of si-FOXO3a into HCT116 reversed the metformin-induced cellular ROS induction, indicating that FOXO3a/MnSOD is the key regulator for cellular ROS level. Viability readout with M, E, and F alone decreased slightly, but the combination of three drugs dramatically decreased cell survival in HCT116, A549, and SK-Hep-1 cancer cells but not in HDF cells. ROS levels in HCT116 cells were massively increased by M + E + F combination, but not in HDF cells. Cell cycle analysis showed that of M + E + F combination caused cell death only in HCT116 cells. The combination of M + E + F reduced synergistically mitochondrial membrane potential and mitochondrial electron transport chain complex I and III activities in HCT116 cells when compared with individual treatments. Western blot analysis indicated that DNA damage, apoptosis, autophagy, and necroptosis-realated factors increased in M + E + F-treated HCT116 cells. Oral administration with M + E + F combination for 3 weeks caused dramatic reductions in tumor volume and weight in HCT116 xenograft model of nude mice when compared with untreated ones. Our results suggest that M + E + F have profound anticancer activity both in vitro and in vivo via a cancer cell-specific ROS amplification (CASRA) through ROS-induced DNA damage, apoptosis, autophagy, and necroptosis.

Intratumoral administration of unconjugated Accum™ impairs the growth of pre-established solid lymphoma tumors

The Accum™ technology was initially designed to enhance the bioaccumulation of a given molecule in target cells. It does so by triggering endosomal membrane damages allowing endocytosed products to enter the cytosol, escaping the harsh environmental cues of the endosomal lumen. In an attempt to minimize manufacturing hurdles associated with Accum™ conjugation, we tested whether free Accum™ admixed with antigens could lead to outcomes similar to those obtained with conjugated products. Surprisingly, unconjugated Accum™ was found to promote cell death in vitro, an observation further confirmed on various murine tumor cell lines (EL4, CT-26, B16, and 4 T1). At the molecular level, unconjugated Accum™ triggers the production of reactive oxygen species and elicits immunogenic cell death while retaining its innate ability to cause endosomal damages. When administered as a monotherapy to animals with pre-established EL4 T-cell lymphoma, Accum™ controlled tumor growth in a dose-dependent manner, and its therapeutic effect relies on CD4 and CD8 T cells. Although unconjugated Accum™ synergizes with various immune checkpoint inhibitors (anti-CTLA4, anti-PD-1, or anti-CD47) at controlling tumor growth, its therapeutic potency could not be further enhanced when combined with all three tested immune checkpoint inhibitors at once due to its dependency on a specific dosing regimen. In sum, we report in this study an unprecedented new function for unconjugated Accum™ as a novel anticancer molecule. These results could pave the path for a new line of investigation aimed at exploring the pro-killing properties of additional Accum™ variants as a mean to develop second-generation anticancer therapeutics.

Protease-activated receptor 2 attenuates doxorubicin-induced apoptosis in colon cancer cells

Drug resistance represents a major problem in cancer treatment. Doxorubicin (adriamycin) is an injectable DNA intercalating drug that halts cancer cell growth by inhibiting topoisomerase 2, but its long-term effectiveness is compromised by onset of resistance. This study demonstrates that expression of the PAR2 gene in human colon adenocarcinoma tissue samples was the highest among 32 different cancer types (n = 10,989), and higher in colon adenocarcinoma tissues (n = 331) than normal colon tissues (n = 308), revealing an association between PAR2 expression and human colon cancer. HT29 cells are a human colorectal adenocarcinoma cell line that is sensitive to the chemotherapeutic drug doxorubicin and also expresses PAR2. We find that PAR2 activation in HT29 cells, either by an endogenous protease agonist (trypsin) or an exogenous peptide agonist (2f-LIGRL-NH2), significantly reduces doxorubicin-induced cell death, reactive oxygen species production, caspase 3/7 activity and cleavage of caspase-8 and caspase-3. Moreover, PAR2-mediated MEK1/2-ERK1/2 pathway induced by 2f-LIGRL-NH2 leads to upregulated anti-apoptotic MCL-1 and Bcl-xL proteins that promote cellular survival. These findings suggest that activation of PAR2 compromises efficacy of doxorubicin in colon cancer. Further support for this conclusion came from experiments with human colon cancer HT29 cells, either with the PAR2 gene deleted or in the presence of a pharmacological antagonist of PAR2, which showed full restoration of all doxorubicin-mediated effects. Together, these findings reveal a strong link between PAR2 activation and signalling in human colon cancer cells and increased survival against doxorubicin-induced cell death. They support PAR2 antagonism as a possible new strategy for enhancing doxorubicin therapy.

Buthionine sulfoximine and chemoresistance in cancer treatments: a systematic review with meta-analysis of preclinical studies

Buthionine sulfoximine (BSO) is a synthetic amino acid that blocks the biosynthesis of reduced glutathione (GSH), an endogenous antioxidant cellular component present in tumor cells. GSH levels have been associated with tumor cell resistance to chemotherapeutic drugs and platinum compounds. Consequently, by depleting GSH, BSO enhances the cytotoxicity of chemotherapeutic agents in drug-resistant tumors. Therefore, the aim of this study was to conduct a systematic review with meta-analysis of preclinical studies utilizing BSO in cancer treatments. The systematic search was carried out using the following databases: PubMed, Web of Science, Scopus, and EMBASE up until March 20, 2023, in order to collect preclinical studies that evaluated BSO, alone or in association, as a strategy for antineoplastic therapy. One hundred nine investigations were found to assess the cytotoxic potential of BSO alone or in combination with other compounds. Twenty-one of these met the criteria for performing the meta-analysis. The evidence gathered indicated that BSO alone exhibits cytotoxic activity. However, this compound is generally used in combination with other antineoplastic strategies, mainly chemotherapy ones, to improve cytotoxicity to carcinogenic cells and treatment efficacy. Finally, this review provides important considerations regarding BSO use in cancer treatment conditions, which might optimize future studies as a potential adjuvant antineoplastic therapeutic tool.

Phytochemical characterization and toxicological activity attributed to the acetonic extract of South American Vassobia breviflora

The particular plant species found in southern Brazil, Vassobia breviflora (Solanaceae) has only a few apparent studies examining its biological effect. Thus, the aim of the present study was to determine the activity of the acetone extract fraction derived from V. breviflora. Four compounds were identified by ESI-qTOF-MS: eucalrobusone R, aplanoic acid B, pheophorbide A, and pheophytin A. In addition, 5 compounds were identified by HPLC-PDA-MS/MS: all-trans-lutein, 15-cis-lutein, all-trans-β-carotene, 5,8-epoxy-β-carotene, and cis-β-carotene. Cell lines A549 (lung cancer), A375 (melanoma cancer) and HeLa (cervical cancer) were incubated with different concentrations of each studied extract using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and 2'-7'dichlorofluorescin diacetate (DCFH-DA) assays. The acetonic extract exhibited cytotoxic activity at a concentration of 0.03 mg/ml in the HeLa strain and 0.1 mg/ml in the others. In addition to increased production of reactive oxygen species (ROS). Antibacterial activity was assessed utilizing minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in 9 ATCCs strains and 7 clinical isolates, as well as determination of biofilm production. Data demonstrated that MIC and MBC were approximately 256 mg/ml in most of the strains tested and antibiofilm effect at S. aureus, S. epidermidis, A. baumannii, and E. faecalis, concentrations below the MIC. Genotoxic activity on plasmid DNA did not produce significant elevated levels in breaks in the isolated genetic material.

Anti-cancer activity of Marsdenialongise A, a new C21 steroidal glycoside isolated from Marsdenia longipes W.T. Wang (Apocynaceae)

C21 steroidal glycosides are a group of natural compounds with biological activities such as anti-cancer, anti-microbial, and anti-viral properties. In this study, we isolated and determined the structure of a new C21 steroidal glycoside, named Marsdenialongise A from Marsdenia longipes W.T. Wang, using nuclear magnetic resonance spectroscopy and mass spectra data. Marsdenialongise A is a derivative of tenacigenin B and was isolated for the first time from a plant. The inhibitory effect of Marsdenialongise A on cancer cells was evaluated through MTT and cell migration assays, cell cycle, and apoptosis analyses. The results of the MTT assay showed that Marsdenialongise A reduces the cell viability of cancer cells, with the AGS cell line being more sensitive than other cell lines, with an IC50 value of 5.69 µM (for 48 h of treatment). Marsdenialongise A also exhibited an ability to prevent the migration of cancer cells in AGS cells. Further analysis using flow cytometry has revealed that Marsdenialongise A is capable of inducing cell cycle arrest and apoptosis. The overexpression of reactive oxygen species (ROS) production induced by Marsdenialongise A can be considered a cause that leads to the influence on the cell cycle and apoptosis of cancer cells. Thus, Marsdenialongise A can be considered a potential anti-cancer agent.

Cytotoxic activity of quinolinequinones in cancer: In vitro studies, molecular docking, and ADME/PK profiling

Lead molecules containing 1,4-quinone moiety are intriguing novel compounds that can be utilized to treat cancer owing to their antiproliferative activities. Nine previously reported quinolinequinones (AQQ1-9) were studied to better understand their inhibitory profile to produce potent and possibly safe lead molecules. The National Cancer Institute (NCI) of Bethesda chose all quinolinequinones (AQQ1-9) based on the NCI Developmental Therapeutics Program and tested them against a panel of 60 cancer cell lines. At a single dose and five further doses, AQQ7 significantly inhibited the proliferation of all leukemia cell lines and some breast cancer cell lines. We investigated the in vitro cytotoxic activities of the most promising compounds, AQQ2 and AQQ7, in MCF7 and T-47D breast cancer cells, DU-145 prostate cancer cells, HCT-116 and COLO 205 colon cancer cell lines, and HaCaT human keratinocytes using the MTT assay. AQQ7 showed particularly high cytotoxicity against MCF7 cells. Further analysis showed that AQQ7 exhibits anticancer activity through the induction of apoptosis without causing cell cycle arrest or oxidative stress. Molecular docking simulations for AQQ2 and AQQ7 were conducted against the COX, PTEN, and EGFR proteins, which are commonly overexpressed in breast, cervical, and prostate cancers. The in vitro ADME and in vivo PK profiling of these compounds have also been reported.

Bioinspired and self-restorable alginate-tyramine hydrogels with plasma reinforcement for arthritis treatment

Long-standing administration of disease-modifying antirheumatic drugs confirms their clinical value for managing rheumatoid arthritis (RA). Nevertheless, there are emergent worries over unwanted adverse risks of systemic drug administration. Hence, a novel strategy that can be used in a drug-free manner while diminishing side effects is immediately needed, but challenges persist in the therapy for RA. To this end, herein we conjugated tyramine (TYR) with alginate (ALG) to form ALG-TYR and then treated it for 5 min with oxygen plasma (ALG-TYR + P/5 min). It was shown that the ALG-TYR + P/5 min hydrogel exhibited favorable viscoelastic, morphological, mechanical, biocompatible, and cellular heat-shock protein amplification behaviors. A thorough physical and structural analysis was conducted on the ALG-TYR + P/5 min hydrogel, revealing favorable physical characteristics and uniform porous structural features within the hydrogel. Moreover, ALG-TYR + P/5 min not only effectively inhibited inflammation of RA but also potentially regulated lesion immunity. Once ALG-TYR + P/5 min was intra-articularly administered to joints of rats with zymosan-induced arthritis, we observed that ALG-TYR + P/5 min could ameliorate syndromes of RA joint. This bioinspired and self-restorable ALG-TYR + P/5 min hydrogel can thus serve as a promising system to provide prospective outcomes to potentiate RA therapy.

Piperlongumine is a ligand for the orphan nuclear receptor 4A1 (NR4A1)

Piperlongumine and derivatives are being developed as anticancer agents which act primarily as inducers of reactive oxygen species (ROS) in cancer cell lines. Many of the anticancer activities of piperlongumine resemble those observed for bis-indole derived compounds that bind the orphan nuclear receptor 4A1 (NR4A1) and act as inverse receptor agonists to inhibit NR4A1-regulated pro-oncogenic pathways and genes. In this study we show that like other NR4A1 inverse agonists piperlongumine inhibited RKO, SW480 and HCT116 colon cancer cell growth migration and invasion and induced apoptosis. Piperlongumine also downregulated the pro-reductant isocitrate dehydrogenase 1 (IDH1) and thioredoxin domain-containing 5 (TXNDC5) gene products resulting in the induction of ROS as previously observed for other inverse NR4A1 agonists. ROS also induced sestrin2 and this resulted in activation of AMPK phosphorylation and inhibition of mTOR pathway signaling. It has previously been reported that these pathways/genes are also regulated by inverse NR4A1 agonists or by knockdown of NR4A1. We also observed that piperlongumine directly bound NR4A1, inhibited NR4A1-dependent transactivation and interactions of the NR4A1/Sp1 complex bound to the GC-rich promoter of the NR4A1-regulated G9a gene.

A fluorene derivative inhibits human hepatocellular carcinoma cells by ROS-mediated apoptosis, anoikis and autophagy

Fluorene was previously reported to have anticancer activity against human cancer cells. In this study, we examined the in vitro function of 9-methanesulfonylmethylene-2, 3-dimethoxy-9 H -fluorene (MSDF), a novel fluorene derivative, its anticancer potential in human hepatocellular carcinoma (HCC) cells and its underlying molecular mechanism. The disruption of cellular homeostasis caused by MSDF was found to promote reactive oxygen species (ROS) generation, leading to the activation of cellular apoptosis. As a survival strategy, cells undergo autophagy during oxidative stress. MSDF-induced apoptosis occurred through both receptor-mediated extrinsic and mitochondrial-mediated intrinsic routes. The development of acidic vesicular organelles and the accumulation of LC3-II protein suggest an increase in the autophagic process. Apoptosis was detected by double staining. The MAPK/ERK and PI3K/Akt signaling pathways were indeed suppressed during treatment. Along with elevated ROS generation and apoptosis, MSDF also caused anoikis and cell death by causing cells to lose contact with their extracellular matrix. ROS production was induced by MSDF and sustained by an NAC scavenger. MSDF-induced apoptosis led to increased autophagy, as shown by the suppression of apoptosis by Z-VAD-FMK. However, inhibition of autophagy by inhibitor 3-MA increased MSDF-induced apoptosis. More evidence shows that MSDF downregulated the expression of immune checkpoint proteins, suggesting that MSDF could be used in the future as an adjuvant to improve the effectiveness of HCC immunotherapy. Altogether, our results highlight the potential of MSDF as a multitarget drug for the treatment of HCC.

In Situ and Real-Time Monitoring of Mitochondria-Endoplasmic Reticulum Crosstalk in Apoptosis via Surface-Enhanced Resonance Raman Spectroscopy

The crosstalk between mitochondria and endoplasmic reticula plays a crucial role in apoptotic pathways in which reactive oxygen species (ROS) produced by microsomal monooxygenase (MMO) are believed to accelerate cytochrome c release. Herein, we successfully demonstrate the potential of surface-enhanced resonance Raman spectroscopy (SERRS) for monitoring MMO-derived ROS formation and ROS-mediated cytochrome c release. Silver nanoparticles coated with nickel shells are used as both Raman signal enhancers and electron donors for cytochrome c. SERRS of cytochrome c is found to be sensitive to ROS, allowing for in situ probing of ROS formation with a cell death inducer. Label-free evaluation of ROS-induced apoptosis is achieved by SERRS-based monitoring of cytochrome c release in living cells. This study verifies the capability of SERRS for label-free, in situ, and real-time monitoring of the mitochondria-endoplasmic reticulum crosstalk in apoptosis and provides a novel strategy for the rational design and screening of ROS-inducing drugs for cancer treatment.

Antioxidant and Cytotoxic Potential of Carlina vulgaris Extract and Bioactivity-Guided Isolation of Cytotoxic Components

Carlina vulgaris is a poorly understood plant in the context of biological activity, despite its widespread application in ethnomedicine in numerous European countries. The aim of this study was to assess the cytotoxic potential of the plant against human colorectal adenocarcinoma (HT29) and to isolate the plant components linked to this effect. Ultra-high performance liquid chromatography with a high-resolution/quadrupole time-of-flight mass spectrometer (UHPLC-HR/QTOF/MS-PDA) was used for the phytochemical characterization of the extract. Liquid-liquid extraction and preparative chromatography were employed for fractionation purposes. Our investigation demonstrated that the ethyl acetate fraction from C. vulgaris showed significant cytotoxicity, and a bioactivity-guided approach led to the isolation of oxylipins, including traumatic acid, pinellic acid, and 9,10-dihydroxy-8-oxsooctadec-12-enic acid. The structures of the compounds were confirmed by nuclear magnetic resonance spectroscopy. Among these compounds, the last one exhibited significant cytotoxicity, though without selectivity, and traumatic acid was characterized by mild cytotoxicity. The cytotoxicity was linked to intracellular reactive oxygen species generation.

A MYC-controlled redox switch protects B lymphoma cells from EGR1-dependent apoptosis

Refractory and relapsed B cell lymphomas are often driven by the difficult-to-target oncogene MYC. Here, we report that high MYC expression stimulates proliferation and protects B lymphoma cells from apoptosis under normal oxidative stress levels and that compounds including N-acetylcysteine (NAC) and vitamin C (VitC) induce apoptosis by reducing oxidative stress. NAC and VitC injections effectively reduce tumor growth in lymphoma cells with high MYC expression but not in those with low MYC expression. MYC knockdown confers tumor resistance to NAC and VitC, while MYC activation renders B cells sensitive to these compounds. Mechanistically, NAC and VitC stimulate MYC binding to EGR1 through Cys117 of MYC, shifting its transcriptional output from cell cycle to apoptosis gene expression. These results identify a redox-controlled mechanism for MYC's role in maintaining proliferation and preventing apoptosis, offering a potential therapeutic rationale for evaluating NAC or VitC in patients with MYC-driven B cell lymphoma.

The Antimalarial Drug Artesunate Mediates Selective Cytotoxicity by Upregulating HO-1 in Melanoma Cells

Despite great efforts to develop new therapeutic strategies to combat melanoma, the prognosis remains rather poor. Artesunate (ART) is an antimalarial drug displaying anti-cancer effects in vitro and in vivo. In this in vitro study, we investigated the selectivity of ART on melanoma cells. Furthermore, we aimed to further elucidate the mechanism of the drug with a focus on the role of iron, the induction of oxidative stress and the implication of the enzyme heme oxygenase 1 (HO-1). ART treatment decreased the cell viability of A375 melanoma cells while it did not affect the viability of normal human dermal fibroblasts, used as a model for normal (healthy) cells. ART's toxicity was shown to be dependent on intracellular iron and the drug induced high levels of oxidative stress as well as upregulation of HO-1. Melanoma cells deficient in HO-1 or treated with a HO-1 inhibitor were less sensitive towards ART. Taken together, our study demonstrates that ART induces oxidative stress resulting in the upregulation of HO-1 in melanoma cells, which subsequently triggers the effect of ART's own toxicity. This new finding that HO-1 is involved in ART-mediated toxicity may open up new perspectives in cancer therapy.

Mefenamic Acid-Upregulated Nrf2/SQSTM1 Protects Hepatocytes against Oxidative Stress-Induced Cell Damage

Mefenamic acid (MFA) is a commonly prescribed non-steroidal anti-inflammatory drug (NSAID) with anti-inflammatory and analgesic properties. MFA is known to have potent antioxidant properties and a neuroprotective effect against oxidative stress. However, its impact on the liver is unclear. This study aimed to elucidate the antioxidative effects of MFA and their underlying mechanisms. We observed that MFA treatment upregulated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Treatment with various anthranilic acid derivative-class NSAIDs, including MFA, increased the expression of sequestosome 1 (SQSTM1) in HepG2 cells. MFA disrupted the interaction between Kelch-like ECH-associated protein 1 (Keap1) and Nrf2, activating the Nrf2 signaling pathway. SQTM1 knockdown experiments revealed that the effect of MFA on the Nrf2 pathway was masked in the absence of SQSTM1. To assess the cytoprotective effect of MFA, we employed tert-Butyl hydroperoxide (tBHP) as a ROS inducer. Notably, MFA exhibited a protective effect against tBHP-induced cytotoxicity in HepG2 cells. This cytoprotective effect was abolished when SQSTM1 was knocked down, suggesting the involvement of SQSTM1 in mediating the protective effect of MFA against tBHP-induced toxicity. In conclusion, this study demonstrated that MFA exhibits cytoprotective effects by upregulating SQSTM1 and activating the Nrf2 pathway. These findings improve our understanding of the pharmacological actions of MFA and highlight its potential as a therapeutic agent for oxidative stress-related conditions.

Antibacterial Properties of Methanolic Leaf Extracts of Melia azedarach L. against Gram-Positive and Gram-Negative Pathogenic Bacteria

Melia azedarach L., a Meliaceae family tree, is widely used in traditional folkloric medicine for its pharmaceutical properties. In the present study, we investigated the phytochemical composition of four methanolic leaf extracts of M. azedarach of various origins (Algeria and Tunisia) using high-performance liquid chromatography (HPLC). The antibacterial efficacy and mechanisms of action against Gram-positive and Gram-negative pathogenic microorganisms were then evaluated. Our findings revealed a presence of phenolic acids and flavonoids, such as gallic acid, chlorogenic acid, caffeic acid, hyperoside, isoquercetin, quercetin, and isorhamnetin both in Algerian and Tunisian localities, with an abundance of phenolic acids compared to flavonoids. Additionally, the studied extracts exhibit a broad spectrum of antibacterial activities, with MIC values ranging from 31.25 mg/mL to 125 mg/mL. Methanolic leaf extracts of M. azedarach from Algeria exhibited more potent biofilm eradication, with a percentage of inhibition reaching 72.17% against the S. aureus strain. Furthermore, inhibitory concentrations of tested substances, particularly the extract from the Relizane area, were capable of disrupting the membrane integrity of the treated bacteria as well as producing oxidative stress through ROS generation. Likewise, our results reveal that plant extract induces lipid peroxidation by raising MDA levels in comparison to untreated cells, particularly with the plant extract of Blida. M. azedarach extracts also reduced the synthesis of antioxidant enzymes (CAT and SOD). Our findings illustrate that M. azedarach remains a plant with significant antibacterial potential and distinct mechanisms of action that are closely related to the origins of this specimen.

Prosopis juliflora (Sw.) DC phytochemicals induce apoptosis and inhibit cell proliferation signaling pathways, EMT, migration, invasion, angiogenesis and stem cell markers in melanoma cell lines

ETHNOPHARMACOLOGICAL RELEVANCE

Prosopis juliflora (Sw.), DC is a xerophytic plant species that extensively grow in Asia, Africa, Australia, and Brazil. From ancient time P. juliflora is being utilized in various folk remedies for example in wound healing, fever, inflammation, measles, excrescences, diarrhea and dysentery. Traditionally, gum, paste, and smoke obtained from the leaves and pods are applied for anticancer, antidiabetic, anti-inflammatory, and antimicrobial purposes.

AIM OF THE STUDY

Our previous studies have demonstrated the promising potential of Prosopis Juliflora leaves methanol extract (PJLME) against breast cancer, and suggested its possible integration as a complementary medicine for the effective management of breast cancer. However, evidence against how PJLME mechanistically target the cancer proliferative pathways and other targets is poorly understood. The basic aim of the present study was to understand the anti-melanoma potential of PJLME against B16f10 cells with possible mechanisms of action.

MATERIALS AND METHODS

MTT assay was used to determine cell viability. Wound and transwell migration assay was performed to check migration potential of cells after PJLME treatment, while clonogenic assay was carried out to understand its colony inhibition actvity. Flow cytometry was used to perform annexin V/PI assay (apoptosis assay), ROS assay, cell cycle analysis. In-vitro angiogenesis assay was performed to check formation of capillary like vascular structure after PJLME treatment. Apoptotic genes, signaling pathways markers, EMT markers and stem cell markers were determined by western blotting. In-vivo BALB/C mice xenograft model study was performed to check the effect of PJLME on in-vivo melanoma tumor growth.

RESULTS

The experimental outcome of the present study has clearly demonstrated the inhibition of growth, migration, invasion, colony formation and apoptosis inducing potential of PJLME against mouse melanoma cancer cells. Treatment of B16F10 melanoma cells with PJLME resulted in arrest of cell cycle at G0/G1 phase. Annexin V-FITC/PI assay confirmed the apoptosis inducing potential of PJLME in B16F10 and A375 melanoma cells. Furthermore, Western blot experiments confirmed that the treatment of PJLME downregulates the expression of anti-apoptotic gene like Bcl2 and increase the expression profile of pro-apoptotic genes like Bax, Bad, and Bak in B16F10 melanoma cells. HUVEC (Human umbilical vein endothelial cells) tube formation assay clearly demonstrated the anti-angiogenic potential of PJLME. The study also revealed that PJLME has potential to inhibit the Akt and Erk signaling pathways which are participating in cancer cell proliferation, migration, invasion etc. The outcome of qRT-PCR and immunoblotting analysis clearly unveiled that PJLME treatment leads to downregulation of epithelial-mesenchymal transition (EMT) as well as stem cell markers. Finally, the in-vivo animal xenograft model study also revealed the anti-melanoma potential of PJLME by significantly inhibiting the B16F10 melanoma tumor growth in BALB/c mice model. The LC-ESI-MS/MS analysis of PJLME showed the presence of variety of bioactive molecules associated with anticancer effects.

CONCLUSION

The outcome of the present investigation clearly demonstrated the anti-melanoma potential of PJLME against B16f10 melanoma cells. PJLME can be explored as an adjuvant or complementary therapy against melanoma cancer, however further studies are required to understand the clinical efficacy of PJLME. Nevertheless, it can be further explored as a promising resource for identification of novel anticancer candidate drug.

SLC1A5 is a novel biomarker associated with ferroptosis and the tumor microenvironment: a pancancer analysis

Solute carrier family 1 member 5 (SLC1A5) is a member of the solute carrier (SLC) superfamily of transporters and plays an important role in tumors as a key transporter of glutamine into cells. However, the relationship between SLC1A5, which is involved in immune regulation, and immune cell infiltration in the tumor microenvironment has not been elucidated, and the relationship between SLC1A5 and ferroptosis is rarely reported. Therefore, we comprehensively analyzed the expression level of SLC1A5 across cancers and compared it with that in normal tissues. Then, the relationship between SLC1A5 expression and the tumor immune microenvironment was analyzed by single-cell analysis, gene set enrichment analysis (GSEA), and Tumor Immune Estimation Resource (TIMER). Next, the correlations of the SLC1A5 expression level with immunotherapy response, immunomodulator expression, tumor mutation burden (TMB) and microsatellite instability (MSI) were evaluated. Finally, in vitro experiments verified that SLC1A5 participates in ferroptosis of glioma cells to regulate tumor progression. Our results indicated that SLC1A5 is aberrantly expressed in most cancer types and closely associated with prognosis. The GSEA results showed that SLC1A5 is involved in immune activation processes and closely related to the infiltration levels of different immune cells in different cancer types. Upon further investigation, we found that SLC1A5 is a suppressor of ferroptosis in glioma, and SLC1A5 knockdown inhibited the proliferation and migration of glioma cells in vitro. In conclusion, we conducted a pancancer analysis of SLC1A5, demonstrated its role as a prognostic biomarker in cancer patients and explored its potential biological functions.

On the Role of ROS and Glutathione in the Mode of Action Underlying Nrf2 Activation by the Hydroxyanthraquinone Purpurin

Purpurin is a major anthraquinone present in the roots of Rubia cordifolia (madder). Purpurin is known to activate Nrf2 (Nuclear transcription factor erythroid 2-related factor 2) EpRE (electrophile responsive element) mediated gene expression as a potential beneficial effect. This study aimed to elucidate the balance between the electrophilicity or pro-oxidant activity of purpurin underlying the Nrf2 induction. For this, Nrf2 activation with modified intracellular glutathione (GSH) levels was measured in an Nrf2 CALUX reporter gene assay. In addition, both cell-free and intracellular ROS formation of purpurin with modified (intracellular) GSH levels at different pH were quantified using the DCF-DA assay. GSH adduct formation was evaluated by UPLC and LC-TOF-MS analysis. GSH and GSSG levels following purpurin incubations were quantified by LC-MS/MS. We show that Nrf2 induction by purpurin was significantly increased in cells with buthionine sulfoximine depleted GSH levels, while Nrf2 induction was decreased upon incubation of the cells with N-acetylcysteine being a precursor of GSH. In cell-free incubations, ROS formation increased with increasing pH pointing at a role for the deprotonated form of purpurin. Upon incubations of purpurin with GSH at physiological pH, GSH adduct formation appeared negligible (<1.5% of the added purpurin). The addition of GSH resulted in conversion of GSH to GSSG and significantly reduced the ROS formation. Together these results demonstrate that Nrf2 induction by purpurin originates from intracellular ROS formation and not from its electrophilicity, which becomes especially relevant when intracellular GSH levels can no longer scavenge the ROS. The present study demonstrated that the efficiency of intracellular Nrf2 activation by purpurin and related anthraquinones will depend on (i) their pKa and level of deprotonation at the intracellular pH, (ii) the oxidation potential of their deprotonated form and (iii) the intracellular GSH levels. Thus, the Nrf2 induction by purpurin depends on its pro-oxidant activity and not on its electrophilicity.

A metabolic map of the DNA damage response identifies PRDX1 in the control of nuclear ROS scavenging and aspartate availability

While cellular metabolism impacts the DNA damage response, a systematic understanding of the metabolic requirements that are crucial for DNA damage repair has yet to be achieved. Here, we investigate the metabolic enzymes and processes that are essential for the resolution of DNA damage. By integrating functional genomics with chromatin proteomics and metabolomics, we provide a detailed description of the interplay between cellular metabolism and the DNA damage response. Further analysis identified that Peroxiredoxin 1, PRDX1, contributes to the DNA damage repair. During the DNA damage response, PRDX1 translocates to the nucleus where it reduces DNA damage-induced nuclear reactive oxygen species. Moreover, PRDX1 loss lowers aspartate availability, which is required for the DNA damage-induced upregulation of de novo nucleotide synthesis. In the absence of PRDX1, cells accumulate replication stress and DNA damage, leading to proliferation defects that are exacerbated in the presence of etoposide, thus revealing a role for PRDX1 as a DNA damage surveillance factor.

Effects of dietary supplementation of Gracilaria lemaneiformis-derived sulfated polysaccharides on the growth, antioxidant capacity, and innate immunity of rabbitfish (Siganus canaliculatus)

The dietary supplementation of red seaweed-derived polysaccharides has been shown to be beneficial to fish and shellfish aquaculture. However, the function of red seaweed (Gracilaria lemaneiformis)-extracted polysaccharide (GLP) on the health status of rabbitfish (Siganus canaliculatus) is still unknown. This study explored the influences of GLP on growth performance, antioxidant activity, and immunity of rabbitfish. Herein, the fish were fed commercial pelleted feed incorporated with the diverse amount of GLP: 0 (control), 0.10 (GLP0.10), and 0.15 g kg^-1 (GLP0.15) for 60 days. The results demonstrated that dietary GLP0.15 significantly elevated FBW and WG, while feed utilization efficiency improved (reduced feed conversion ratio and increased protein efficiency ratio) upon GLP0.10 treatment, regarding the control (P < 0.05). Also, dietary administration of GLP0.15 suggestively improved the serum acid phosphatase and lysozyme activity as well as hepatic total antioxidant capacity, catalase, and superoxide dismutase activity. In contrast, GLP0.15decreased the serum alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and malonaldehyde activity when compared to the control (P<0.05). Moreover, the lipase (36.08 and 16.46 U/mgprot in GLP0.10 and GLP0.15, respectively) and amylase (0.43 and 0.23 U/mgprot in GLP0.10 and GLP0.15, respectively) activity recorded the maximum values than the control (8.61 and 0.13 U/mgprot, respectively).Further, the intestinal morphometry was developed (such as increased villus length, width, and area) in the fish fed with a GLP-supplemented diet compared to the control. The KEGG pathway analysis unveiled that several differentially expressed genes (DEGs) in control vs. GLP0.10 and control vs. GLP0.15 were associated with metabolic or immune-associated pathways like antigen processing and presentation, phagosome, complement and coagulation cascades, and platelet activation. The DEGs, namely C3, f5, fgb, MHC1, and cfb, were evaluated in control vs. GLP0.10 and C3 and MHC1 in control vs. GLP0.15, suggesting their possible contributions to GLP-regulated immunity. Additionally, the cumulative mortality of rabbitfish after the Vibrio parahaemolyticus challenge was lower in both GLP0.10 (8.88%) and GLP0.15 (11.11%) than in control (33.33%) (P<0.05). Thus, these findings direct the potential use of GLP as an immunostimulant and growth promoter in rabbitfish aquaculture.