| 1 |
Lipid bilayer permeability and fluidity |
↑ membrane fluidity and permeability; ↑ pore formation (dose-dependent) |
↑ membrane fluidity and permeability; membrane disruption at high concentration |
P |
Changes membrane organization and transport |
Central physicochemical mechanism. Low concentrations produce subtle bilayer changes; higher concentrations can cause dehydration, thinning and transient aqueous defects. |
| 2 |
Malignant cell differentiation |
↑ terminal differentiation in HL-60, Friend erythroleukemia and selected other models |
Context-dependent differentiation effects |
G |
Reduces immature malignant phenotype |
Classical but model-specific effect, usually requiring prolonged exposure to approximately 1–2% DMSO. Not clinically validated as leukemia differentiation therapy. |
| 3 |
Cell-cycle progression |
↓ G1 to S progression; ↑ reversible G1 arrest (context-dependent) |
↓ proliferation at elevated concentrations |
G |
Cytostatic growth suppression |
Often accompanies differentiation. Arrest may be reversible after DMSO removal and should not automatically be classified as tumour-cell killing. |
| 4 |
Transcription and chromatin state |
↑ differentiation-associated transcription; ↓ oncogenic phenotype in selected models |
Broad gene-expression changes (model-dependent) |
G |
Reprograms cell phenotype |
DMSO is not a selective epigenetic drug. Effects include changes in chromatin conformation, transcription factors and tumour-suppressive genes such as HLJ1 in specific models. |
| 5 |
Apoptosis and inflammatory cell death |
↑ apoptosis or caspase activation (high concentration only); ↓ apoptosis in some models |
↑ cytotoxicity and caspase-1 activation (high concentration only) |
R–G |
Concentration-dependent cell death or cytoprotection |
Direction is not uniform. Approximately 2.5% DMSO induced apoptosis selectively in one transformed keratinocyte model, whereas other studies found suppression of apoptosis. |
| 6 |
Mitochondrial integrity |
↓ mitochondrial function at cytotoxic concentrations; preservation reported under some oxidative injuries |
↔ or ↑ mitochondrial preservation at low protective exposures; ↓ function at high concentration |
R–G |
Bidirectional mitochondrial modulation |
Secondary and highly context-dependent. DMSO may either contribute to cytotoxicity or protect mitochondria from specific oxidants. |
| 7 |
Hydroxyl radical and oxidative injury |
↓ hydroxyl-radical-mediated damage; possible ↓ efficacy of ROS-dependent therapy |
↓ oxidative tissue injury |
P–R |
Radical scavenging and cytoprotection |
DMSO is widely used experimentally as a hydroxyl-radical scavenger. This is not equivalent to broad antioxidant activity against every ROS species. |
| 8 |
Radiosensitization and radioprotection |
↓ radiation injury in some systems; mixed effects on treatment response |
↓ hydroxyl-radical-mediated radiation injury |
P–R |
Predominantly radioprotective under radical-mediated conditions |
DMSO should not be classified generally as a radiosensitizer. Radical scavenging can protect both normal and malignant cells and may confound radiation experiments. |
| 9 |
Drug and solute penetration |
↑ intracellular and transmembrane delivery of dissolved agents |
↑ dermal and tissue uptake of drugs and contaminants |
P |
Delivery enhancement |
Can increase apparent potency, toxicity or distribution of co-administered compounds. DMSO vehicle controls do not isolate this interaction when permeability itself changes. |
| 10 |
Cryoprotection |
↑ post-thaw viability of tumour cells and cellular therapeutics |
↑ post-thaw viability; ↓ ice-crystal injury |
P |
Prevents freezing-associated cellular damage |
Major clinical and laboratory use. Residual DMSO in infused cryopreserved products can produce acute infusion reactions and other toxicity. |
| 11 |
Clinical Translation Constraint |
In-vitro active concentrations often exceed practical systemic anticancer exposure |
Systemic, ocular, hypersensitivity and interaction concerns |
G |
Limits anticancer translation |
No established anticancer indication. Biological activity is nonselective, concentration-dependent and inseparable from solvent, membrane and delivery effects. |