Proanthocyanidins / COX2 Cancer Research Results

PACs, Proanthocyanidins: Click to Expand ⟱

Features:

Proanthocyanidins (PACs; condensed tannins) = oligomeric/polymeric flavan-3-ols (e.g., catechin/epicatechin units); abundant in grape seed, cocoa, cranberry, apple skin, pine bark. Degree of polymerization (DP) influences bioactivity and absorption.
Primary mechanisms (conceptual rank):
1) Redox modulation → direct ROS scavenging + metal chelation (Fe²⁺/Cu²⁺).
2) NRF2 activation → endogenous antioxidant enzymes (HO-1, NQO1, GCLC).
3) Anti-inflammatory signaling → ↓ NF-κB / ↓ COX-2 / ↓ cytokines.
4) Anti-proliferative / pro-apoptotic signaling in cancer (MAPK, PI3K/Akt modulation; dose-dependent).
5) Anti-angiogenic / anti-metastatic effects (VEGF, MMPs; model-dependent).
PK / bioavailability: monomers/low-DP oligomers absorbed; higher-DP polymers poorly absorbed but metabolized by gut microbiota to phenolic acids; plasma parent PAC levels modest vs many in-vitro studies.
In-vitro vs systemic exposure: many cancer studies use ≥10–100 µM equivalents; achievable circulating levels typically lower and largely conjugated/metabolite-driven.
Clinical evidence status: strongest human data in vascular/cardiometabolic endpoints; oncology evidence largely preclinical/adjunct.

Polyphenols found in cranberry, blueberry, and grape seeds.

Proanthocyanidin B2 (PB2) is a type of dimer flavonoid that is found in grape seed, pine bark, wine, and tea leaves [17]. PB2 has been shown to possess various bioactivities, including anti-oxidant, anti-inflammation, and anti-obesity activities, and it has also shown efficacy in the treatment of cancer, cardiovascular disease, type 2 diabetes, ulcerative colitis, as well as acute liver injury. PKM2 is the target of proanthocyanidin B2

PB2 also suppressed glucose uptake and lactate levels via the direct inhibition of the key glycolytic enzyme, PKM2.

Proanthocyanidins (PACs) — Cancer-Relevant Pathways

Rank	Pathway / Axis	Cancer Cells	Normal Cells	TSF	Primary Effect	Notes / Interpretation
1	ROS tone / redox balance	↓ (low–mod dose); ↑ (high concentration only)	↓	P→R	Antioxidant; metal chelation	Catechol-rich structure scavenges radicals; pro-oxidant shift reported at high doses in tumors (model-dependent).
2	NRF2 axis	↑ (context-dependent)	↑	R→G	Endogenous antioxidant induction	↑ HO-1/NQO1; protective in normal tissue; may support tumor stress resistance (context-dependent).
3	NF-κB / inflammatory signaling	↓	↓	R→G	Anti-inflammatory	Reduces cytokines, COX-2; anti-tumor microenvironment effect plausible.
4	PI3K/Akt / MAPK pathways	↓ proliferation (model-dependent)	↔	R→G	Growth signaling attenuation	Observed in breast, colon, prostate models; dose and DP dependent.
5	Apoptosis (caspase activation)	↑ (dose-dependent)	↔ / ↓	R→G	Pro-apoptotic signaling	Mitochondrial depolarization reported; often supra-physiologic exposure.
6	Angiogenesis (VEGF)	↓ (preclinical)	↔	G	Anti-angiogenic	↓ VEGF expression in models; human oncologic data limited.
7	Ferroptosis axis	↓ (anti-lipid-ROS bias)	↓	P→R	Lipid peroxidation inhibition	Strong antioxidant property may counter ferroptotic strategies (context-dependent).
8	Clinical Translation Constraint	—	—	—	Bioavailability & dose gap	High-DP PACs poorly absorbed; many in-vitro doses exceed realistic plasma exposure; adjunct role most plausible.

TSF Legend: P: 0–30 min | R: 30 min–3 hr | G: >3 hr

Proanthocyanidins (PACs) — Alzheimer’s Disease–Relevant Axes

Rank	Pathway / Axis	Cells (neurons/glia)	TSF	Primary Effect	Notes / Interpretation
1	Lipid peroxidation / neuronal ROS	↓	P	Neuroprotective antioxidant	Reduces oxidative damage markers in models; aligns with AD oxidative stress hypothesis.
2	NRF2 activation	↑	R→G	Endogenous antioxidant upregulation	Supports neuronal resilience; mostly preclinical evidence.
3	Neuroinflammation (NF-κB)	↓	R→G	Microglial modulation	Reduced cytokine production in animal models.
4	Aβ aggregation / toxicity	↓ (preclinical)	G	Interference with amyloid aggregation	Reported inhibition of Aβ fibrillization in vitro; human data limited.
5	BDNF / synaptic plasticity	↑ (model-dependent)	G	Neurotrophic signaling	Observed in flavanol-rich cocoa/grape extract studies; translation to PAC isolates unclear.
6	Clinical Translation Constraint	—	—	Dietary-level evidence	Human trials mostly use flavanol-rich extracts; cognitive effects modest and stage-dependent.

TSF Legend: P: 0–30 min | R: 30 min–3 hr | G: >3 hr

COX2, cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein: Click to Expand ⟱

Source: HalifaxProj(inhibit)

Type:

Cyclooxygenase-2 (COX-2) is an enzyme that plays a critical role in the conversion of arachidonic acid to prostaglandins, which are lipid compounds involved in various physiological processes, including inflammation, pain, and fever. COX-2 is an inducible enzyme, meaning its expression is typically low in normal tissues but can be upregulated in response to inflammatory stimuli, growth factors, and certain oncogenic signals.
-Cyclooxygenase-2 (COX-2), the rate-limiting enzyme in prostaglandin biosynthesis, plays a key role in inflammation and circulatory homeostasis.
-COX-2 is an inducible enzyme that is upregulated in response to pro-inflammatory signals, including cytokines (e.g., IL-1β, TNF-α) and growth factors.

COX-2 is often overexpressed in various tumors, including colorectal, breast, lung, and prostate cancers.
The prostaglandins produced by COX-2, particularly prostaglandin E2 (PGE2), have several effects that can facilitate cancer progression:
Cell Proliferation: PGE2 can promote the proliferation of cancer cells by activating signaling pathways such as the PI3K/Akt and MAPK pathways.
Nonselective NSAIDs, such as aspirin and ibuprofen, inhibit both COX-1 and COX-2. Epidemiological studies have suggested that regular use of NSAIDs may reduce the risk of certain cancers, particularly colorectal cancer.
Drugs specifically targeting COX-2, such as celecoxib, have been developed.

COX-2 and xanthine oxidase are ROS-producing pro-oxidant enzymes that contribute to inflammation. Elevated COX‑2 levels, often found in inflammatory conditions or certain types of cancers, can contribute to increased production of ROS.

Scientific Papers found: Click to Expand⟱

1240-

GSE,

PACs,

Grape Seed Proanthocyanidins Inhibit Melanoma Cell Invasiveness by Reduction of PGE2 Synthesis and Reversal of Epithelial-to-Mesenchymal Transition

in-vitro,

Melanoma,

A375

in-vitro,

Melanoma,

Hs294T

TumCMig↓, TumCI↓, COX2↓, PGE2↓, NF-kB↓, EMT↓, E-cadherin↑, Vim↓, Fibronectin↓, N-cadherin↓,

Showing Research Papers: 1 to 1 of 1

* indicates research on normal cells as opposed to diseased cells
Total Research Paper Matches: 1

Pathway results for Effect on Cancer / Diseased Cells:

Proliferation, Differentiation & Cell State ⓘ

EMT↓, 1,

Migration ⓘ

E-cadherin↑, 1, Fibronectin↓, 1, N-cadherin↓, 1, TumCI↓, 1, TumCMig↓, 1, Vim↓, 1,

Immune & Inflammatory Signaling ⓘ

COX2↓, 1, NF-kB↓, 1, PGE2↓, 1,
Total Targets: 10

Pathway results for Effect on Normal Cells:

Total Targets: 0

Scientific Paper Hit Count for: COX2, cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein

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#:136  Target#:66  State#:%  Dir#:1
  wNotes=0  sortOrder:rid,rpid