Cynaropicrin / NRF2 Cancer Research Results

CYN, Cynaropicrin: Click to Expand ⟱
Features:

Cynaropicrin (CYN) — a guaianolide sesquiterpene lactone and major bitter bioactive constituent of Cynara cardunculus / globe artichoke, particularly artichoke leaves. Major reported cancer-relevant effects include apoptosis induction, proliferation inhibition, cell-cycle disruption, tubulin/c-Myc signaling interference, and suppression of inflammatory and survival pathways including NF-κB and JAK/STAT signaling. Clinical anticancer efficacy has not been established; evidence remains predominantly preclinical.

Cynaropicrin — a naturally occurring guaianolide-type sesquiterpene lactone and electrophilic bitter phytochemical found particularly in the leaves of Cynara cardunculus / Cynara scolymus (artichoke). It is formally classified as a plant-derived sesquiterpene lactone. Its α-methylene-γ-lactone and related α,β-unsaturated carbonyl functionality can act as Michael acceptors toward cellular thiols, providing a plausible chemical basis for glutathione depletion, thiol-protein modification, oxidative stress, and inhibition of redox-sensitive signaling proteins. Cancer studies indicate substantial mechanistic heterogeneity, with ROS-dependent mitochondrial injury, STAT3/c-Myc signaling suppression, apoptosis, parthanatos, paraptosis-like death, and context-dependent autophagy/mitophagy among the best-supported effects. Cynaropicrin is not an approved anticancer drug.

Primary mechanisms (ranked):

  1. Electrophilic thiol reactivity with GSH/thioredoxin systems → redox disruption, ROS accumulation, mitochondrial dysfunction, and cancer-cell death.
  2. STAT3-centered survival signaling inhibition, including ↓ STAT3 phosphorylation/transcriptional activity and, in some models, ↓ LIFR/STAT3 signaling.
  3. Mitochondrial ROS and stress signaling → p38/JNK activation, mitochondrial membrane-potential loss, apoptosis, mitophagy, or paraptosis-like death depending on tumor model.
  4. ↓ c-Myc with associated ↓ AKT/ERK/STAT3 signaling and inhibition of proliferative transcriptional programs.
  5. Microtubule network disruption with G2/M cell-cycle disturbance.
  6. DNA damage → PARP1 hyperactivation → PAR accumulation → AIF mitochondrial-to-nuclear translocation and parthanatos in multiple myeloma.
  7. Intrinsic and extrinsic apoptosis signaling with ↑ Bax and caspase-3/-8/-9 and ↓ Bcl-2 in responsive cancer cells.
  8. ER-stress/autophagy modulation; autophagy can be cytotoxic through PINK1/Parkin-mediated mitophagy or cytoprotective through p62/Keap1/NRF2 depending on cancer type.
  9. Secondary anti-inflammatory signaling including NF-κB/TNF-α suppression, more strongly established outside direct cancer-treatment models.

Bioavailability / PK relevance: Human pharmacokinetics, metabolism, plasma exposure, oral bioavailability, tissue distribution, and a validated therapeutic exposure range for purified cynaropicrin have not been adequately established. Its electrophilic Michael-acceptor chemistry may produce rapid reaction with glutathione and protein thiols, potentially limiting free systemic exposure while also contributing to pharmacodynamic activity. Artichoke-leaf supplementation cannot be assumed to reproduce pharmacologic exposure to purified cynaropicrin.

In-vitro vs systemic exposure relevance: Most anticancer experiments use low-micromolar concentrations, commonly approximately 1–10 µM depending on model, with some activity near 1–2 µM. Whether these concentrations are achievable and sustainable in human tumors after oral or systemic administration is unknown because dedicated human cynaropicrin PK data are lacking. Therefore, concentrations effective in vitro should not presently be considered clinically exposure-validated.

Clinical evidence status: Preclinical. Anticancer evidence includes numerous cell-line studies plus xenograft mouse and zebrafish tumor models, but no established human anticancer efficacy and no validated therapeutic dosing regimen for purified cynaropicrin. Human studies of artichoke preparations for metabolic or gastrointestinal indications do not establish cancer efficacy or the PK/safety profile of purified cynaropicrin.

Cynaropicrin Cancer-Relevant Mechanisms

Rank Pathway / Axis Cancer Cells Normal Cells TSF Primary Effect Notes / Interpretation
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.

P: 0–30 min    R: 30 min–3 hr    G: >3 hr
NRF2, nuclear factor erythroid 2-related factor 2: Click to Expand ⟱
Source: TCGA
Type: Antiapoptotic
Nrf2 is responsible for regulating an extensive panel of antioxidant enzymes involved in the detoxification and elimination of oxidative stress. Thought of as "Master Regulator" of antioxidant response.
-One way to estimate Nrf2 induction is through the expression of NQO1.
NQO1, the most potent inducer:
SFN 0.2 μM,
quercetin (2.5 μM),
curcumin (2.7 μM),
Silymarin (3.6 μM),
tamoxifen (5.9 μM),
genistein (6.2 μM ),
beta-carotene (7.2μM),
lutein (17 μM),
resveratrol (21 μM),
indol-3-carbinol (50 μM),
chlorophyll (250 μM),
alpha-cryptoxanthin (1.8 mM),
and zeaxanthin (2.2 mM)

1. Raising Nrf2 enhances the cell's antioxidant defenses and ↓ROS. This strategy is used to decrease chemo-radio side effects.
2. Downregulating Nrf2 lowers antioxidant defenses and ↑ROS. In cancer cells this leads to DNA damage, and cell death.
3. However there are some cases where increasing Nrf2 paradoxically causes an increase in ROS (cancer cells). Such as cases of Mitochondial overload, signal crosstalk, reductive stress

-In some cases, Nrf2 is overexpressed in cancer cells, which can lead to the activation of genes involved in cell proliferation, angiogenesis, and metastasis. This can contribute to the development of resistance to chemotherapy and targeted therapies.
-Increased Nrf2 expression: Lung, Breast, Colorectal, Prostrate.
Decreased Nrf2 expression: Skine, Liver, Pancreatic.
-Nrf2 is a cytoprotective transcription factor which demonstrated both a negative effect as well as a positive effect on cancer
- "promotes Nrf2 translocation from the cytoplasm to the nucleus," means facilitates the movement of Nrf2 into the nucleus, thereby enhancing the cell's antioxidant and cytoprotective responses. -Major regulator of Nrf2 activity in cells is the cytosolic inhibitor Keap1.

Nrf2 Inhibitors and Activators
Nrf2 Inhibitors: Brusatol, Luteolin, Trigonelline, VitC, Retinoic acid, Chrysin
Nrf2 Activators: SFN, OPZ EGCG, Resveratrol, DATS, CUR, CDDO, Api
- potent Nrf2 inducers from plants include sulforaphane, curcumin, EGCG, resveratrol, caffeic acid phenethyl ester, wasabi, cafestol and kahweol (coffee), cinnamon, ginger, garlic, lycopene, rosemany

Nrf2 plays dual roles in that it can protect normal tissues against oxidative damage and can act as an oncogenic protein in tumor tissue.
– In healthy tissues, NRF2 activation helps protect cells from oxidative damage and maintains cellular homeostasis.
– In many cancers, constitutive activation of NRF2 (often through mutations in NRF2 itself or loss-of-function mutations in KEAP1) leads to an enhanced antioxidant capacity.
– This upregulation can promote tumor cell survival by enabling cancer cells to thrive under oxidative stress, resist chemotherapeutic agents, and sustain metabolic reprogramming.
– Elevated NRF2 levels have been implicated in promoting tumor growth, metastasis, and resistance to therapy in various malignancies.
– High or sustained NRF2 activity is frequently associated with aggressive tumor phenotypes, poorer prognosis, and decreased overall survival in several cancer types.
– While its activation is essential for protecting normal cells from oxidative stress, aberrant or sustained NRF2 activation in tumor cells can lead to enhanced survival, therapeutic resistance, and tumor progression.

NRF2 inhibitors: (to decrease antioxidant defenses and increase cell death from ROS).
-Brusatol: most cited natural inhibitors of Nrf2.
-Luteolin: luteolin can reduce Nrf2 activity in specific cancer models and may enhance cell sensitivity to chemotherapy. However, luteolin is also known as an antioxidant, and its influence on Nrf2 can sometimes be context dependent.
-Apigenin: certain studies to down‑regulate Nrf2 in cancer cells: Dose and context dependent .
-Oridonin:
-Wogonin: although its effects might be cell‑ and dose‑specific.
- Withaferin A

Scientific Papers found: Click to Expand⟱
7441- CYN,    Cynaropicrin attenuates UVB-induced oxidative stress via the AhR-Nrf2-Nqo1 pathway
- in-vitro, Nor, NA
*ROS↓, *NRF2↑, *Inflam↓, *IL6↓, *TNF-α↓, *AhR↑, *NQO1↑,
7451- CYN,    Inhibitory effects of cynaropicrin on human melanoma progression by targeting MAPK, NF‐κB, and Nrf‐2 signaling pathways in vitro
- in-vitro, Melanoma, A375
TumCP↓, Casp3↑, Apoptosis↑, TumCMig↓, TumCI↓, ERK↓, NF-kB↓, ROS↓, HO-1↑, NRF2↑, Bcl-2↓, NF-kB↓, other↝,

Showing Research Papers: 1 to 2 of 2

* indicates research on normal cells as opposed to diseased cells
Total Research Paper Matches: 2

Pathway results for Effect on Cancer / Diseased Cells:


Redox & Oxidative Stress(tgid=1) ⓘ

HO-1↑, 1,   NRF2↑, 1,   ROS↓, 1,  

Cell Death(tgid=5) ⓘ

Apoptosis↑, 1,   Bcl-2↓, 1,   Casp3↑, 1,  

Transcription & Epigenetics(tgid=7) ⓘ

other↝, 1,  

Proliferation, Differentiation & Cell State(tgid=12) ⓘ

ERK↓, 1,  

Migration(tgid=13) ⓘ

TumCI↓, 1,   TumCMig↓, 1,   TumCP↓, 1,  

Immune & Inflammatory Signaling(tgid=16) ⓘ

NF-kB↓, 2,  
Total Targets: 12

Pathway results for Effect on Normal Cells:


Redox & Oxidative Stress(tgid=1) ⓘ

NQO1↑, 1,   NRF2↑, 1,   ROS↓, 1,  

Cell Death(tgid=5) ⓘ

AhR↑, 1,  

Immune & Inflammatory Signaling(tgid=16) ⓘ

IL6↓, 1,   Inflam↓, 1,   TNF-α↓, 1,  

Clinical Biomarkers(tgid=22) ⓘ

IL6↓, 1,  
Total Targets: 8

Scientific Paper Hit Count for: NRF2, nuclear factor erythroid 2-related factor 2
Query results interpretion may depend on "conditions" listed in the research papers.
Such Conditions may include : 
  -low or high Dose
  -format for product, such as nano of lipid formations
  -different cell line effects
  -synergies with other products 
  -if effect was for normal or cancerous cells

Filter Conditions: Pro/AntiFlg:%  IllCat:%  CanType:%  Cells:%  prod#:451  Target#:226  State#:%  Dir#:2
  wNotes=0  sortOrder:rid,rpid

 

Home Page