Selective Cytotoxic and Redox-Associated Effects of Plant-Derived Terpenoids in Human Glioblastoma Cells.

Comparative Evaluation of Cytotoxic, Genotoxic, and Apoptotic Effects of Naringenin and Naringenin-Oxime in Colorectal Cancer Cells.

Colorectal cancer (CRC) remains a major global health concern, accounting for 9.6% of all cancer cases and 9.3% of cancer-related deaths. Natural compounds with anticancer properties have gained increasing interest due to their potential for reduced toxicity. This study investigated the cytotoxic, genotoxic, and apoptotic effects of naringenin-oxime (NG-Ox) on colorectal cancer (LoVo) and normal colon epithelial cells (CCD18-Co). NG-Ox was synthesized from NG, and its structure was verified by 1H-NMR spectroscopy. Cell viability was assessed using the MTT assay, apoptosis via acridine orange/ethidium bromide staining, DNA damage by the Comet assay, and intracellular reactive oxygen species (iROS) levels through fluorometric analysis. Long-term proliferative potential was evaluated using a colony formation assay, and principal component analysis (PCA) was employed to integrate the overall cellular responses. Both NG and NG-Ox reduced LoVo cell viability in a dose-dependent manner. NG showed greater selectivity for cancer cells, whereas NG-Ox induced stronger DNA damage and apoptosis but also exhibited higher toxicity in normal cells. ROS induction was most prominent with 5-FU, whereas NG and NG-Ox produced moderate increases. PCA confirmed these findings, demonstrating an inverse correlation between cell viability and ROS, apoptosis, and DNA damage. NG was more closely associated with apoptosis and ROS responses, whereas NG-Ox was more strongly associated with DNA damage. In conclusion, NG-Ox showed strong DNA-damaging and proapoptotic activity in CRC cells; however, its lack of selectivity compared with NG limits its immediate therapeutic potential.

NaHS inhibits cell proliferation by enhancing oxidative stress and apoptosis in HCT116 cells

ONC212 Induces Ferroptosis-Associated Cell Death in Glioblastoma Cells

Aim: Glioblastoma (GBM) is an aggressive primary brain tumor with limited treatment options. Ferroptosis, an iron-dependent cell death characterized by lipid peroxidation and oxidative stress, is a promising therapeutic target. This study investigated the anticancer effects of the imipridone derivative ONC212 in GBM cells and examined whether its cytotoxicity involves ferroptosis-related mechanisms.Material and Methods: U87 and U251 cells were treated with increasing ONC212 concentrations. Viability was assessed by CCK-8, proliferation by BrdU incorporation (24–72 h). Ferroptosis-associated changes were evaluated by measuring ferrous iron (Fe²⁺), malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS). Expression of ferroptosis-related genes GPX4 and ACSL4 was analyzed by qRT-PCR. Ferrostatin-1 (Fer-1) was used to confirm ferroptosis involvement.Results: ONC212 reduced viability in a time- and dose-dependent manner [IC₅₀ (95% CI): 18.7 µM (17.3-20.1), 9.6 µM (8.8-10.4), and 6.2 µM (5.7-6.7) at 24, 48, and 72 h, respectively]. BrdU incorporation decreased by 46.9% and 79.4% at 24 h and 72 h, respectively, following treatment with the 24-hour IC₅₀ concentration (18.7 µM). Ferroptosis-associated oxidative stress was evident through increased Fe²⁺, MDA, ROS, and GSH depletion. ONC212 upregulated ACSL4 (2.14‑fold) and reduced GPX4 expression by 62%. Fer-1 pretreatment partially reversed these alterations, supporting the involvement of ferroptosis-associated mechanisms. Similar results were obtained in U251 cells.Conclusion: ONC212 exerts potent cytotoxic and anti-proliferative effects in GBM cells and provides preliminary evidence suggesting that it induces ferroptosis-associated cell death through modulation of oxidative stress and ferroptosis‑associated gene expression. Targeting ferroptosis with ONC212 may represent a promising therapeutic strategy for GBM.

4-Chloro-7-Nitrobenzofurazan induces ROS-mediated p53 dependent apoptosis in human fibrosarcoma cells

Three Thiol-Reactive Reagents drive Synergistic Lethality in Glioblastoma cells

Glioblastoma (GBM) is the most prevalent malignant primary brain tumor. Disruption of the redox state of the cell through cysteine (Cys) reactive residues has been suggested to play a role in the progression of GBM. Here, we demonstrate that the addition of acrylamide (ACR), a thiol-reactive molecule that covalently modifies redox-related proteins and disrupts critical redox signaling pathways, further amplifies the cytotoxic effects and the synergistic lethality induced by auranofin (Auf) and buthionine sulfoximine (DL-BSO). We established a minimal triple-thiol cocktail of ACR/Auf/BSO, which enhances suppression of cell growth in various cancer cell lines. This combination of ACR, BSO, and Auf, which causes a complete cell death in U87MGMG, U87MGΔEGFR, A431, PC12 and SH-SY5Y cells induces significantly less toxicity in primary rat cortex neuronal cultures. The synergy observed is strongly associated with increased activation of ERK1/2 and p38MAPK phosphorylation, as well as the inhibition of the STAT3 signaling pathways, which are both critical for cell survival and proliferation. In contrast, primary neuronal cortical cells, which exhibit minimal toxicity with the minimal ACR/Auf/BSO combination, display no activation of these antioxidant/anti-inflammatory molecular pathways. The combination of the oxidizing reagents induces whole-cell and mitochondrial reactive oxygen species (ROS) production in patient-derived GBM cells and reduces proliferation of a human GBM organoid model. We suggest that combining multiple Cys-associated redox targets is a putative therapeutic strategy for GBM, which offers a promising approach for improving treatment outcomes in GBM and other malignancies.

Synergistic In Vitro Effects of Minor Phytocannabinoids and Melatonin Combinations Against Human Glioblastoma Cells

The prognosis of glioblastoma (GBM) patients remains dismal due to chemoresistance. Repurposing of natural and endogenous compounds, such as the pineal hormone melatonin (MLT) and minor phytocannabinoids like cannabinol (CBN) or cannabigerol (CBG), represents a promising strategy. This study investigates the cytotoxic potential of combining these phytocannabinoids with MLT, evaluating their efficacy both alone and synergistically with temozolomide (TMZ) to overcome drug resistance. To achieve this, cytotoxicity, synergy (Bliss model), and selectivity were evaluated in U87, T98, and U251 GBM lines and normal astrocytes. Mechanisms of damage were characterized via Western blot (γH2AX and PARP-1), flow cytometry using fluorescent dyes/probes (DCFDA, JC-1, MitoBright, BODIPY, PI, and Annexin-V), or the protein marker COX IV and confocal analysis. The results demonstrated that CBN-MLT and CBG-MLT regimens exerted synergistic cytotoxicity while sparing healthy astrocytes. Notably, combining these regimens (U87: MLT 0.3 mg/mL + CBN 25 µM; MLT 0.2 mg/mL + CBG 15 µM. T98: MLT 0.7 mg/mL + CBN 25 µM; MLT 0.6 mg/mL + CBG 30 µM. U251: MLT 0.4 mg/mL + CBN 20 µM; MLT 0.5 mg/mL + CBG 35 µM) with TMZ significantly enhanced chemotherapeutic efficacy, overcoming baseline effects of TMZ in these cell lines. The combinations induced necrotic cell death characterized by severe double-strand DNA damage. This was driven by an early accumulation of intracellular ROS, which triggered mitochondrial depolarization, loss of organelle mass, and lipid peroxidation. CBN combinations consistently triggered more robust biochemical alterations than CBG-based treatments. Taken together, this study provides a strong preclinical basis for utilizing minor cannabinoids combined with MLT in GBM management. Crucially, this co-treatment emerges as a promising approach to potentiate TMZ efficacy, offering a novel and potentially effective therapeutic strategy to counter GBM resilience.