Vitamin C (Ascorbic Acid) / NRF2 Cancer Research Results

VitC, Vitamin C (Ascorbic Acid): Click to Expand ⟱
Features:
High-dose vitamin C: Some studies have suggested that high-dose vitamin C may be effective in treating certain types of cancer, such as ovarian cancer and pancreatic cancer.
Symptoms of vitamin C deficiency include fatigue, weakness, poor wound healing, ecchymoses, xerosis, lower extremity edema, and musculoskeletal pain—most of them are often observed in end-stage cancer patients. -Vitamin C is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and is important for immune system function.
-Ascorbic Acid, Different levels in different Organs
Homeostasis ranging from about 0.2 mM in the muscle and heart, and up to 10 mM in the brain and adrenal gland. -(Note the Oncomagnetic success in the brain also was then under conditions of high Vitamin C)

-Ascorbic acid is an electron donor
Ascorbic Acid, can be a Pro-oxidant
"The pro-oxidative activity of ascorbic acid (Figure 2) is associated with the interaction with transition metal ions (especially iron and copper). Under conditions of high, millimolar ascorbate concentration, vitamin C catalyzes the reduction of free transition metal ions, which causes the formation of oxygen radicals."
Ascorbic Acid, formation of H2O2 (Hydrogen Peroxide)
Many studies indicate the toxicity of ascorbate to cancer cells. Much evidence indicates that the underlying phenomenon is the pro-oxidative activity of ascorbate, which induces the formation of H2O2 and oxidative stress.
"ascorbate at concentrations achieved only by i.v. administration may be a pro-drug for formation of H(2)O(2)"
-High dose VitC therapy may not be for those with kidney problems
-Oral supplement up to 10g/day?
-Direct regulator of TET↑
-caution for (G6PD-) deficient patients receiving vitamin C infusions

-Note plasma half-life 30mins to 1hr, 1.5-2hr elimination half-life.
oral BioAv water soluble, but has limitiations as 100mg yeilds 60uM/L in plasma, but 1000mg only yeilds 85uM/L. mM concentration are required for effectiveness on cancer cells. Hence why IV administration is common. Boosting HIF increases the intracellular uptake of oxidized VitC
Pathways:
- high dose induces ROS production in cancer cells. Otherwise well known antioxidant in normal cells.
- ROS↑ related: MMP↓(ΔΨm), ER Stress↑, Caspases↑, DNA damage↑, cl-PARP↑,
- Lowers AntiOxidant defense in Cancer Cells: NRF2↓">NRF2, TrxR↓**, SOD↓, GSH↓ Catalase↓ HO1↓ GPx↓
- Raises AntiOxidant defense in Normal Cells: ROS↓, NRF2↑">NRF2, SOD↑, GSH↑, Catalase↑,
- lowers Inflammation : NF-kB↓, COX2↓, p38↓, Pro-Inflammatory Cytokines : NLRP3↓, IL-1β↓, TNF-α↓, IL-6↓, IL-8↓
- inhibit Growth/Metastases : TumMeta↓, TumCG↓, EMT↓, MMPs↓, MMP2↓, MMP9↓, TIMP2, IGF-1↓, VEGF↓, NF-κB↓,
- reactivate genes thereby inhibiting cancer cell growth : P53↑, TET↑
- cause Cell cycle arrest : TumCCA↑, cyclin D1↓, CDK2↓,
- inhibits Migration/Invasion : TumCMig↓, TumCI↓, TNF-α↓, ERK↓, EMT↓, TET1↓,
- inhibits glycolysis /Warburg Effect and ATP depletion : HIF-1α↓, PKM2↓, cMyc↓, GLUT1↓, LDH↓, LDHA↓, HK2↓, PFKs↓, PDKs↓, ECAR↓, GRP78↑, Glucose↓, GlucoseCon↓
- inhibits angiogenesis↓ : VEGF↓, HIF-1α↓,
- Others: PI3K↓, AKT↓, STAT↓, AMPK, ERK↓, JNK,
- Synergies: chemo-sensitization, chemoProtective, RadioSensitizer, RadioProtective, Others(review target notes), Neuroprotective, Cognitive, Hepatoprotective,

- Selectivity: Cancer Cells vs Normal Cells
Selenium supplementation may protect cells against iron-dependent cell death by supporting increased expression of selenoproteins, including GPX4, which defend against oxidative stress. Meaning it may decrease effectiveness of high dose VitC.(#4468)


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⟱
4883- LT,  CHr,  BRU,  VitC,    An update of Nrf2 activators and inhibitors in cancer prevention/promotion
- Review, Var, NA
*NRF2↓,
3108- VitC,  QC,    The role of quercetin and vitamin C in Nrf2-dependent oxidative stress production in breast cancer cells
- in-vitro, BC, MDA-MB-231 - in-vitro, Lung, A549
NRF2↓, HO-1↓, ROS↑, NRF2⇅,
2592- VitC,    Ascorbic acid restores sensitivity to imatinib via suppression of Nrf2-dependent gene expression in the imatinib-resistant cell line
- in-vitro, CLL, NA
NRF2↓, GSH↓,
114- VitC,  QC,    Chemoprevention of prostate cancer cells by vitamin C plus quercetin: role of Nrf2 in inducing oxidative stress
- in-vitro, Pca, PC3 - in-vitro, Pca, DU145
GPx↓, GSR↓, NQO1↓, NRF2↓, ROS↑,

Showing Research Papers: 1 to 4 of 4

* indicates research on normal cells as opposed to diseased cells
Total Research Paper Matches: 4

Pathway results for Effect on Cancer / Diseased Cells:


Redox & Oxidative Stress

GPx↓, 1,   GSH↓, 1,   GSR↓, 1,   HO-1↓, 1,   NQO1↓, 1,   NRF2↓, 3,   NRF2⇅, 1,   ROS↑, 2,  
Total Targets: 8

Pathway results for Effect on Normal Cells:


Redox & Oxidative Stress

NRF2↓, 1,  
Total Targets: 1

Scientific Paper Hit Count for: NRF2, nuclear factor erythroid 2-related factor 2
4 Vitamin C (Ascorbic Acid)
2 Quercetin
1 Luteolin
1 Chrysin
1 brusatol
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#:166  Target#:226  State#:%  Dir#:1
wNotes=0 sortOrder:rid,rpid

 

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