| 1 |
Thiol redox system and ROS |
↓ GSH; ↓ TrxR/Trx function; ↑ ROS and mtROS |
↔ or ↓ ROS (context-dependent) |
P/R |
Oxidative stress-driven cytotoxicity |
The electrophilic sesquiterpene-lactone structure can react with cellular thiols. ROS scavenging with NAC repeatedly attenuates cytotoxicity, supporting a causal role. Normal keratinocytes show NRF2-dependent antioxidant effects under UVB stress, illustrating strong cell-context dependence. |
| 2 |
STAT3 survival signaling |
↓ STAT3 phosphorylation, nuclear signaling and transcriptional activity |
Not adequately characterized |
R/G |
Loss of survival signaling and increased apoptosis |
Reported mechanisms include GSH depletion/S-glutathionylation of STAT3 and suppression of LIFR/STAT3 signaling in colorectal cancer. |
| 3 |
Mitochondrial ROS and p38 MAPK |
↑ mtROS; ↑ p38 MAPK; ↓ mitochondrial membrane potential |
Much weaker cytotoxicity reported in THLE-2 hepatocytes |
P/R/G |
Mitochondrial dysfunction, apoptosis and mitophagy |
Especially strong evidence in HCC. p38 inhibition and ROS scavenging reverse substantial portions of the phenotype. |
| 4 |
c-Myc AKT ERK signaling |
↓ c-Myc; ↓ AKT; ↓ ERK1/2; ↓ STAT3 |
Not adequately characterized |
R/G |
Reduced proliferative signaling |
Prominent in multiple myeloma. c-Myc expression and transcriptional activity are dose-dependently inhibited. |
| 5 |
Microtubule network and cell cycle |
↓ organized microtubules; ↑ G2/M arrest |
Not adequately characterized |
G |
Mitotic disruption and growth arrest |
Direct microtubule-network disorganization has been visualized in treated cells and accompanies G2/M accumulation. |
| 6 |
PARP1 AIF parthanatos |
↑ DNA damage; ↑ PARP1 hyperactivation; ↑ PAR; ↑ nuclear AIF |
Not adequately characterized |
G |
Parthanatos-type cell death |
Demonstrated prominently in multiple myeloma; PARP inhibition partially rescues viability. |
| 7 |
Apoptosis Bax Bcl-2 caspases |
↑ Bax; ↓ Bcl-2; ↑ caspase-3/-8/-9; ↑ PARP cleavage |
Generally less characterized |
G |
Intrinsic and extrinsic apoptosis |
Strong in MDA-MB-231 TNBC cells, leukemia, cervical cancer and several other models; MCF-7 cells showed proliferation inhibition without equivalent apoptotic signaling. |
| 8 |
PINK1 Parkin mitophagy |
↑ mitochondrial PINK1 and Parkin; ↑ LC3-II; ↑ mitophagic flux |
↔ in THLE-2 under comparable experimental conditions |
R/G |
Removal of damaged mitochondria contributing to cell death |
Demonstrated in Hep3B and HepG2 cells. Blocking autophagy or p38 signaling attenuates the cytotoxic phenotype. |
| 9 |
ER stress and paraptosis-like death |
↑ ER stress; ↑ Ca²⁺; ↓ Alix; ↑ cytoplasmic vacuolation |
Not adequately characterized |
R/G |
Caspase-independent paraptosis-like death |
Reported in Hep3B cells. Cytotoxicity was poorly rescued by apoptosis, necroptosis or autophagy inhibitors but strongly attenuated by ROS scavenging. |
| 10 |
JNK and p38 stress MAPK |
↑ JNK; ↑ p38 MAPK (model-dependent) |
Not adequately characterized |
R |
Stress signaling and apoptosis |
Recent colorectal-cancer work links ROS accumulation to JNK/p38 activation and apoptosis. |
| 11 |
NRF2 antioxidant response |
↑ NRF2 during protective autophagy in neuroblastoma (context-dependent) |
↑ AhR-NRF2-NQO1 in UVB-stressed keratinocytes |
R/G |
Adaptive antioxidant response |
NRF2 is not uniformly anticancer here. In neuroblastoma, p62/Keap1/NRF2 activation is cytoprotective and limits cynaropicrin-induced apoptosis; autophagy inhibition attenuates this pathway and enhances cytotoxicity. |
| 12 |
NF-κB inflammatory signaling |
↓ NF-κB activity (context-dependent) |
↓ inflammatory signaling in stimulated normal/immune models |
R/G |
Anti-inflammatory and potentially anti-survival activity |
Well described pharmacologically but less central than ROS/STAT3/mitochondrial mechanisms in direct anticancer studies. |
| 13 |
Chemosensitization |
↑ sensitivity to cytotoxic drugs through ↓ STAT3 signaling |
Not established |
G |
Potential combination-treatment leverage |
STAT3 S-glutathionylation and inhibition can increase tumor-cell sensitivity to chemotherapy; clinical relevance remains untested. |
| 14 |
Clinical Translation Constraint |
Effective concentrations predominantly low micromolar in vitro |
Systemic therapeutic window uncertain |
G |
Limits interpretation of preclinical efficacy |
No validated human PK, tumor exposure, anticancer dosing, or efficacy data for purified cynaropicrin. Electrophilic thiol reactivity may also produce off-target toxicity and rapid biological sequestration. |