Gallic acid / HO-1 Cancer Research Results

GA, Gallic acid: Click to Expand ⟱
Features:
Phenolic acid found in gallnuts, sumac, witch hazel, tea leaves, oak bark. Has antioxidant, antimicrobial and anti-obesity properties.
The GA derivatives include two types: ester and catechin derivatives. The most common ester derivatives of GA are alkyl esters, which are composed mainly of methyl gallate (MG), propyl gallate (PG), octyl gallate (OG), dodecyl gallate (DG), tetradecyl gallate (TG), and hexadecyl gallate (HG), and some of the main catechin derivatives are epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), gallocatechin gallate (GCG), and epigallocatechin gallate (EGCG)

Gallic acid is a naturally occurring polyphenol found in a variety of plant-based foods. Some of the best dietary sources include:

Fruits:
Berries (strawberries, blackberries, blueberries)
Grapes, including red wine (grapes are rich in polyphenols)
Pomegranates and apples
Nuts and Seeds: Walnuts and almonds have been noted to contain GA in their skins
Herbs and Spices: Tea (especially green tea), Sumac and other spices
Other Plants: Gallnuts (from oak trees)

Pathways:
-ROS generation in tumor cells is frequently reported, Antioxidant behavior dominates in normal tissue models -Apoptosis Induction: Activating caspase cascades, Shifting Bax versus Bcl-2, MMP, cyt-c release -Cell Cycle Arrest: typ @ G1 or G2/M checkpoints.
-Anti-inflammatory Effects: inhibiting NF-κB
-reported Angiogenesis Inhibition:
-Modulation of Signaling Pathways: MAPK Pathway, PI3K/Akt Pathway Inhibition, p53 Pathway

Gallic acid exhibits a complex behavior with ROS in cancer cells, acting as both an antioxidant and a pro-oxidant depending on the context and its concentration:

Antioxidant Effects at Low Doses:
-At lower concentrations, gallic acid is typically characterized by its ability to scavenge free radicals, thus reducing oxidative stress.
This antioxidant property may help protect normal cells from DNA damage, reducing the risk of mutations that could lead to cancer.

Pro-oxidant Effects at High Doses: >50-100uM?
-Capable of biphasic redox behavior (antioxidant in normal cells, pro-oxidant in some tumor contexts) -At higher concentrations, GA can exert pro-oxidant effects, generating ROS within cancer cells. Elevated ROS levels can overwhelm the cellular antioxidant defenses of cancer cells, leading to oxidative stress, mitochondrial dysfunction, and ultimately cell death.

Oral bioavailability is well absorbed but subject to rapid conjugation (glucuronide/sulfate/methylated metabolites). Many cytotoxic in-vitro concentrations are in the 10–100 µM range, often higher than typical plasma levels after dietary intake.

Gallic acid — Gallic acid is a naturally occurring trihydroxybenzoic phenolic acid and plant secondary metabolite with antioxidant, pro-oxidant, anti-inflammatory, antimicrobial, and extensively studied preclinical anticancer activity. It is formally classified as a low-molecular-weight polyphenolic phenolic acid and is commonly abbreviated GA. Its chemical identity is 3,4,5-trihydroxybenzoic acid. Dietary and botanical sources include gallnuts, sumac, tea, grapes, berries, pomegranate, mango, walnuts, oak bark, and hydrolysable tannins. GA is also released during digestion or microbial metabolism of gallotannins and galloylated polyphenols. Its anticancer effects are strongly concentration-, cell-type-, redox-, and exposure-dependent.

Primary mechanisms (ranked):

  1. Biphasic redox modulation, with ROS generation and oxidative stress predominating in susceptible cancer cells at cytotoxic concentrations, but ROS scavenging and NRF2-linked antioxidant protection predominating in many normal or inflamed tissues.
  2. Mitochondrial apoptosis through mitochondrial membrane depolarization, Bax/Bcl-2 imbalance, cytochrome-c release, caspase activation, and PARP cleavage.
  3. Suppression of oncogenic survival signaling, particularly PI3K/AKT, STAT3, EGFR, and context-dependent MAPK signaling.
  4. Cell-cycle arrest through modulation of p53, p21, p27, cyclins, and cyclin-dependent kinases, commonly at G1 or G2/M depending on the model.
  5. Suppression of inflammatory and tumor-promoting transcription through NF-κB inhibition and reduced COX-2, IL-6, TNF-α, and related mediators.
  6. Inhibition of angiogenesis through PTEN/AKT/HIF-1α/VEGF signaling and reduced endothelial or tumor-associated vascular responses.
  7. Suppression of invasion, migration, epithelial-mesenchymal transition, and matrix-remodelling pathways, including MMP2, MMP9, Wnt/β-catenin, and selected EMT regulators.
  8. Metabolic disruption through context-dependent inhibition of glycolysis, LDH-associated lactate metabolism, lipid synthesis, and other tumor bioenergetic processes.
  9. Therapy sensitization reported with selected cytotoxic and targeted agents, including paclitaxel, carboplatin, camptothecin, and olaparib, but currently supported mainly by cell-culture evidence.

Bioavailability / PK relevance: GA can be absorbed orally and is among the more readily absorbed simple polyphenols, but absorption is followed by rapid methylation, glucuronidation, sulfation, microbial transformation, and urinary elimination. Circulating exposure consists substantially of conjugated and microbial metabolites rather than persistent free GA. Formulation strategies such as nanoparticles, conjugates, and encapsulation can increase exposure experimentally, but these delivery systems remain investigational.

In-vitro vs systemic exposure relevance: Many anticancer experiments use approximately 10–100 µM GA, with pronounced pro-oxidant cytotoxicity frequently occurring toward the upper portion of this range or above it. These free-compound concentrations commonly exceed sustained plasma concentrations expected from ordinary dietary intake. Consequently, direct systemic anticancer effects demonstrated at high micromolar exposure may not be achievable through food consumption or conventional oral supplementation. Local gastrointestinal exposure, metabolites, tissue accumulation, or engineered delivery could produce different exposure relationships.

Clinical evidence status: Preclinical. GA has extensive cell-culture evidence and a smaller body of animal evidence across multiple tumor types. Human pharmacokinetic and food-intervention studies confirm exposure to GA and its metabolites, but isolated GA has not established anticancer efficacy in randomized clinical trials and is not an approved cancer therapy. Human studies involving polyphenol-rich mango, pomegranate, tea, grape, or botanical preparations cannot be attributed specifically to GA. Therapy-sensitizing activity remains experimental and should not be used to justify combining GA supplements with chemotherapy outside clinical supervision.

Gallic Acid Mechanistic Profile

Rank Pathway / Axis Cancer Cells Normal Cells TSF Primary Effect Notes / Interpretation
1 Biphasic redox modulation ROS ↑; oxidative stress ↑ (dose-dependent) (model-dependent) ROS ↓; radical scavenging ↑; antioxidant capacity ↑ P, R Selective redox destabilization Pro-oxidant tumor effects are most evident at higher in-vitro concentrations; antioxidant effects dominate in many non-malignant injury models.
2 Mitochondrial apoptosis Mitochondrial membrane potential ↓; Bax ↑; Bcl-2 ↓; cytochrome-c ↑; caspases ↑; PARP cleavage ↑ ↔ or apoptosis ↓ under oxidative injury (context-dependent) R, G Intrinsic apoptotic cell death Frequently downstream of ROS accumulation, although mitochondrial and apoptotic responses vary by tumor genotype and concentration.
3 PI3K AKT survival signaling PI3K ↓; p-AKT ↓; mTOR signaling ↓ (model-dependent); PTEN ↑ ↔ or AKT-associated cytoprotection ↑ during inflammatory injury R, G Growth and survival suppression Direction can differ between malignant cells and stressed normal tissues; pathway effects should be entered with context qualifiers.
4 Cell-cycle checkpoints p53 ↑; p21 ↑; p27 ↑; cyclin D1 ↓; cyclin E ↓; G1 or G2/M arrest ↑ ↔ G Cytostasis Arrest phase is model-dependent and should not be generalized to one checkpoint.
5 NF-κB inflammatory signaling NF-κB ↓; COX-2 ↓; IL-6 ↓; TNF-α ↓; pro-survival inflammation ↓ NF-κB ↓; inflammatory cytokines ↓; epithelial protection ↑ R, G Anti-inflammatory and anti-survival signaling One of the more reproducible effects across tumor and non-tumor inflammatory models.
6 MAPK stress signaling JNK ↑; p38 ↑; ERK ↓ or ↔ (context-dependent) Pathologic p38 and ERK activation ↓ or protective signaling ↑ (context-dependent) P, R Stress-response reprogramming MAPK direction depends on cell type, initiating stress, exposure duration, and whether apoptosis or cytoprotection is being measured.
7 Angiogenesis and hypoxia signaling PTEN ↑; AKT ↓; HIF-1α ↓; VEGF ↓; angiogenesis ↓ ↔ G Anti-angiogenic activity Supported by selected ovarian, cervical, and other experimental cancer models; not clinically validated.
8 Invasion and epithelial-mesenchymal transition MMP2 ↓; MMP9 ↓; Wnt/β-catenin ↓; EMT ↓; migration ↓; invasion ↓ ↔ or epithelial barrier integrity ↑ G Anti-invasive phenotype Often secondary to NF-κB, AKT, MAPK, and Wnt pathway modulation.
9 NRF2 antioxidant response NRF2 ↑ or ↓ (context-dependent); HO-1 ↑ or ↓; redox adaptation altered NRF2 ↑; HO-1 ↑; GSH ↑; SOD ↑; catalase ↑ R, G Secondary redox adaptation NRF2 activation is generally cytoprotective in normal tissue but may protect some cancers; prostate-cancer findings indicate model-dependent alteration of the NRF2 HO-1 BACH1 axis.
10 Glycolysis and lipid metabolism LDH activity ↓; lactate production ↓; FASN ↓; glycolytic dependence ↓ (model-dependent) ↔ R, G Metabolic growth restriction The evidence base is smaller and less consistent than that for redox modulation and apoptosis; avoid treating glycolysis inhibition as universal.
11 DNA damage and repair balance DNA damage ↑; p53 response ↑; FEN1 ↓ in nanoparticle studies; repair capacity ↓ (model-dependent) Oxidative DNA damage ↓ at antioxidant exposure R, G Genotoxic stress in cancer cells Free GA and GA-containing nanocarriers are not mechanistically interchangeable; nanoparticle-specific findings require separate qualification.
12 Chemosensitization Paclitaxel response ↑; carboplatin response ↑; camptothecin response ↑; olaparib response ↑ (model-dependent) Chemotherapy-associated injury ↓ or ↔ in limited models G Adjunctive treatment sensitization Evidence is primarily in vitro. Both antioxidant protection and pro-oxidant sensitization are possible, making unsupervised clinical combinations inappropriate.
13 Immune checkpoint and tumor immunity PD-L1 ↓; CD8-positive T-cell activity ↑; antitumor immune response ↑ (model-dependent) Immune homeostasis modulation ↔ G Immune sensitization Promising animal evidence exists, but direct clinical immunotherapy enhancement has not been demonstrated.
14 Clinical Translation Constraint Free systemic GA exposure ↓; conjugation ↑; metabolism ↑; cytotoxic target exposure often not reached Dietary exposure generally tolerated; high-dose isolated exposure insufficiently characterized R, G Exposure and evidence limitation Rapid metabolism, uncertain tumor delivery, formulation heterogeneity, high in-vitro concentrations, and absence of isolated-GA cancer trials limit translation.

P: 0–30 min    R: 30 min–3 hr    G: >3 hr
HO-1, HMOX1: Click to Expand ⟱
Source:
Type:
(Also known as Hsp32 and HMOX1)
HO-1 is the common abbreviation for the protein (heme oxygenase‑1) produced by the HMOX1 gene.
HO-1 is an enzyme that plays a crucial role in various cellular processes, including the breakdown of heme, a toxic molecule. Research has shown that HO-1 is involved in the development and progression of cancer.
-widely regarded as having antioxidant and cytoprotective effects
-The overall activity of HO‑1 helps to reduce the pro‐oxidant load (by degrading free heme, a pro‑oxidant) and to generate molecules (like bilirubin) that can protect cells from oxidative damage

Studies have found that HO-1 is overexpressed in various types of cancer, including lung, breast, colon, and prostate cancer. The overexpression of HO-1 in cancer cells can contribute to their survival and proliferation by:
  Reducing oxidative stress and inflammation
  Promoting angiogenesis (the formation of new blood vessels)
  Inhibiting apoptosis (programmed cell death)
  Enhancing cell migration and invasion
When HO-1 is at a normal level, it mainly exerts an antioxidant effect, and when it is excessively elevated, it causes an accumulation of iron ions.

A proper cellular level of HMOX1 plays an antioxidative function to protect cells from ROS toxicity. However, its overexpression has pro-oxidant effects to induce ferroptosis of cells, which is dependent on intracellular iron accumulation and increased ROS content upon excessive activation of HMOX1.

-Curcumin   Activates the Nrf2 pathway leading to HO‑1 induction; known for its anti‑inflammatory and antioxidant effects.
-Resveratrol  Induces HO‑1 via activation of SIRT1/Nrf2 signaling; exhibits antioxidant and cardioprotective properties.
-Quercetin   Activates Nrf2 and related antioxidant pathways; contributes to anti‑oxidative and anti‑inflammatory responses.
-EGCG     Promotes HO‑1 expression through activation of the Nrf2/ARE pathway; also exhibits anti‑inflammatory and anticancer properties.
-Sulforaphane One of the most potent natural HO‑1 inducers; triggers Nrf2 nuclear translocation and upregulates a battery of phase II detoxifying enzymes.
-Luteolin    Induces HO‑1 via Nrf2 activation; may also exert anti‑inflammatory and neuroprotective effects in various cell models.
-Apigenin   Has been reported to induce HO‑1 expression partly via the MAPK and Nrf2 pathways; also known for anti‑inflammatory and anticancer activities.
Scientific Papers found: Click to Expand⟱
7040- GA,    Effects of gallic acid on acrylamide-induced endoplasmic reticulum stress, neuroinflammation and neuronal apoptosis in rats
- Trial, AD, NA
*SOD↑, *GSH↑, *GPx↑, *Catalase↑, *MDA↓, *TNF-α↓, *IL1β↓, *BAX↓, *Casp3↓, *BDNF↑, *NRF2↑, *HO-1↑,
7034- GA,  RES,    The Growth Inhibitory Effect of Resveratrol and Gallic Acid on Prostate Cancer Cell Lines through the Alteration of Oxidative Stress Balance: The Interplay between Nrf2, HO-1, and BACH1 Genes
- in-vitro, Pca, PC3 - in-vitro, Pca, DU145
TumCG↓, ROS↓, SOD↑, GPx↑, Catalase↑, GSR↑, GSH↑, HO-1↑, NRF2↑,

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) ⓘ

Catalase↑, 1,   GPx↑, 1,   GSH↑, 1,   GSR↑, 1,   HO-1↑, 1,   NRF2↑, 1,   ROS↓, 1,   SOD↑, 1,  

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

TumCG↓, 1,  
Total Targets: 9

Pathway results for Effect on Normal Cells:


Redox & Oxidative Stress(tgid=1) ⓘ

Catalase↑, 1,   GPx↑, 1,   GSH↑, 1,   HO-1↑, 1,   MDA↓, 1,   NRF2↑, 1,   SOD↑, 1,  

Cell Death(tgid=5) ⓘ

BAX↓, 1,   Casp3↓, 1,  

Immune & Inflammatory Signaling(tgid=16) ⓘ

IL1β↓, 1,   TNF-α↓, 1,  

Synaptic & Neurotransmission(tgid=18) ⓘ

BDNF↑, 1,  
Total Targets: 12

Scientific Paper Hit Count for: HO-1, HMOX1
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#:82  Target#:597  State#:%  Dir#:2
  wNotes=0  sortOrder:rid,rpid

 

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