Emodin / PARP Cancer Research Results

EMD, Emodin: Click to Expand ⟱

Features:

Organic compound isolated from rhubarb, buckthorn, knotweed. It has laxative, anticancer, antibacterial, antiinflammatory, and antiviral activities, and is used in traditional Chinese medicine.
Emodin, an anthraquinone derivative found in various plants (e.g., rhubarb, Polygonum cuspidatum).

Pathways:
- Generation of Reactive Oxygen Species (ROS)
- Upregulation Bax downregulation of Bcl‑2, caspase activation and cyt_c release.
- Induce cell cycle arrest at various checkpoints (commonly G0/G1 or G2/M phases.
- Can inhibit NF‑κB activation
– MAPK Pathways
– PI3K/Akt Pathway
- Metalloproteinases (MMPs)

-ic50 cancer cells 10-50uM, normal cells higher(supports a therapeutic window)

Rhubarb species	Common name	Plant part analyzed	Emodin content	Aloe-emodin content	Interpretation
Rheum palmatum	Chinese rhubarb	Dried root and rhizome	Approximately 1.1–2.0 mg/g	Approximately 0.65–1.0 mg/g	Major medicinal source; concentrations vary considerably with origin, plant age, processing, and extraction method.
Rheum officinale	Medicinal rhubarb	Dried root and rhizome	Usually approximately 0.5–2 mg/g	Usually approximately 0.5–2 mg/g	Composition broadly resembles R. palmatum; some samples contain more aloe-emodin than emodin.
Rheum tanguticum	Tangut rhubarb	Root and rhizome; smaller amounts occur in aerial tissues	Moderate to high; commonly approximately 1–3 mg/g in underground tissues	Moderate; commonly below emodin	One of the three principal Chinese medicinal rhubarb species. Tissue distribution differs, and some aerial tissues may contain appreciable emodin.
Rheum australe syn. Rheum emodi	Himalayan or Indian rhubarb	Root and rhizome	Present and frequently a major anthraquinone	Present, generally lower and more variable	Reported concentrations vary widely among wild populations; quantitative results are not directly comparable across extraction methods.
Rheum rhabarbarum / Rheum × hybridum	Garden or culinary rhubarb	Root and rhizome; edible petiole contains much less	Low to moderate in roots; usually trace or low in petioles	Low or trace in petioles; variable in roots	Edible stalks are not compositionally equivalent to medicinal rhubarb roots. Most anthraquinones occur in underground tissues.

In rhubarb, the medicinal material described as “root and rhizome” includes both the true roots and the thick underground stem base from which the leaf stalks emerge.

Emodin — Emodin is a naturally occurring hydroxyanthraquinone and plant secondary metabolite, chemically identified as 1,3,8-trihydroxy-6-methylanthraquinone. It is a small-molecule natural product rather than an approved anticancer drug. Major sources include rhubarb species, Japanese knotweed, buckthorn, Polygonum multiflorum, Polygonum cuspidatum, Rheum palmatum, and several fungi. Emodin is pharmacologically pleiotropic, with redox-active, kinase-modulating, anti-inflammatory, cytotoxic, laxative, and antimicrobial properties. Its anticancer effects remain predominantly preclinical, and emodin should be distinguished from the related compounds aloe-emodin and rhein.

Primary mechanisms (ranked):

Induction of oxidative stress and mitochondrial dysfunction, producing ROS accumulation, mitochondrial membrane depolarization, cytochrome-c release, and caspase-dependent apoptosis.
Suppression of PI3K/AKT/mTOR and related survival signaling, frequently accompanied by AMPK activation, reduced protein synthesis, metabolic stress, and apoptosis.
Modulation of BAX/BCL-2-family proteins and activation of intrinsic and, in some models, extrinsic apoptotic pathways.
Cell-cycle arrest through context-dependent modulation of p53, p21, ATM, cyclins, CDKs, and checkpoint proteins.
Inhibition of NF-κB, STAT3, TLR4, JAK, MAPK, HER2, CK2, and other pro-survival or inflammatory signaling pathways.
Suppression of glycolysis and anabolic metabolism through reduced GLUT1, HK2, PKM2, LDHA, FASN, and AKT/mTOR activity in selected cancer models.
Inhibition of invasion, epithelial–mesenchymal transition, angiogenesis, and cancer-stem-cell phenotypes through reduced MMPs, HIF-1α, VEGF, TGF-β, CXCR4, and mesenchymal signaling.
Induction of autophagy, ER stress, DNA-damage responses, or necroptosis in model-dependent settings.
NRF2/HO-1 activation as a secondary, context-dependent antioxidant response that may protect normal cells but can also oppose emodin-induced cytotoxic oxidative stress.
Chemosensitization through inhibition of survival, resistance, stemness, cholesterol-metabolism, or drug-efflux pathways; the interaction is drug- and tumor-dependent.

Bioavailability / PK relevance: Native emodin has very poor oral bioavailability, estimated at approximately 3% in rat studies. It has low aqueous solubility, incomplete intestinal absorption, extensive intestinal and hepatic glucuronidation and sulfation, and rapid systemic clearance. Circulating exposure is therefore dominated by conjugated metabolites rather than sustained concentrations of free emodin. Nanoparticles, liposomes, phospholipid complexes, prodrugs, and other delivery systems are being investigated but are not established clinical formulations.

In-vitro vs systemic exposure relevance: Most anticancer experiments use approximately 10–100 µM emodin, commonly 20–50 µM. These free-drug concentrations are unlikely to be maintained systemically after conventional oral administration because of poor absorption and rapid conjugation. In-vitro findings therefore substantially overstate the exposure achievable with unformulated oral emodin. Local gastrointestinal exposure may be higher, but this does not establish therapeutically useful tumor exposure.

Clinical evidence status: Preclinical. Evidence consists primarily of cancer-cell studies and rodent xenograft or chemically induced tumor models. Emodin has shown experimental adjunct and chemosensitizing effects with agents including paclitaxel, sorafenib, cisplatin, gemcitabine, and other therapies, but there is no established randomized clinical evidence supporting emodin as a cancer treatment. Emodin is not an FDA-, EMA-, or Health Canada-approved anticancer agent.

Safety: Emodin is not necessarily tumor-selective and can produce ROS, mitochondrial injury, apoptosis, and genotoxic signals in nonmalignant cells at sufficient concentrations. Preclinical literature reports possible hepatotoxicity, nephrotoxicity, reproductive toxicity, gastrointestinal irritation, laxative effects, and complex mutagenicity findings, particularly with high doses or prolonged exposure. It may also affect CYP enzymes, conjugating enzymes, transporters, and the pharmacokinetics of co-administered drugs. Long-term concentrated supplementation should not be considered equivalent to ordinary dietary exposure from rhubarb or other foods.

Mechanistic Profile of Emodin

Rank	Pathway / Axis	Cancer Cells	Normal Cells	TSF	Primary Effect	Notes / Interpretation
1	ROS-driven mitochondrial injury	↑ ROS ↓ mitochondrial membrane potential ↓ ATP	↑ ROS and mitochondrial injury at cytotoxic exposure	P–R	Upstream cytotoxic stress	A central mechanism in many cancer models, but not intrinsically cancer-specific. Redox outcome varies with dose, cell type, antioxidant capacity, and exposure duration.
2	Intrinsic mitochondrial apoptosis	↑ BAX ↓ BCL-2 and BCL-XL ↑ cytochrome-c ↑ caspase-9 and caspase-3 ↑ PARP cleavage	↑ apoptosis at high concentration or prolonged exposure	R–G	Programmed cell death	Frequently follows ROS accumulation and mitochondrial depolarization. Extrinsic Fas and caspase-8 signaling also contributes in some models.
3	PI3K AKT mTOR and AMPK signaling	↓ PI3K ↓ AKT ↓ mTOR ↑ AMPK (context-dependent)	Mixed or tissue-protective modulation (context-dependent)	R–G	Reduced survival and anabolic signaling	Mechanistically important across several tumor types, although AMPK activation is not universal and may differ by metabolic state.
4	Cell-cycle checkpoints and DNA-damage response	↑ ATM ↑ p53 ↑ p21 ↓ cyclin D1, cyclin E, or cyclin B1 ↓ CDK activity	Cell-cycle disturbance possible at cytotoxic exposure	G	G0/G1, S-phase, or G2/M arrest	The arrest point is cell-line and dose-dependent. Emodin should not be assigned to one universal checkpoint.
5	NF-κB TLR4 inflammatory survival signaling	↓ TLR4 ↓ IKK activation ↓ IκBα degradation ↓ NF-κB nuclear activity	↓ inflammatory signaling in many injury models	R–G	Reduced survival, inflammation, and treatment resistance	This axis contributes to both anticancer and anti-inflammatory effects and may reduce cytokine-driven tumor support.
6	JAK STAT3 and receptor kinase signaling	↓ JAK1 and JAK2 ↓ STAT3 ↓ HER2 ↓ CK2 or Src signaling (model-dependent)	Mixed; possible inhibition of physiological kinase signaling	R–G	Reduced proliferation and anti-apoptotic transcription	Direct and indirect kinase effects have been reported, but target dominance varies substantially among tumor models.
7	Glycolysis and metabolic dependency	↓ GLUT1 ↓ HK2 ↓ PKM2 ↓ LDHA ↓ ECAR ↓ glycolysis	PKM2 and metabolic modulation reported (context-dependent)	R–G	Energy stress and reduced biosynthetic capacity	Prominent in selected renal and hepatic cancer models but not yet established as a universal primary mechanism.
8	HIF-1α VEGF angiogenic program	↓ HIF-1α biosynthesis ↓ VEGF ↓ angiogenesis	Potential impairment of physiological hypoxic adaptation at sufficient exposure	G	Reduced hypoxia tolerance and vascular support	Evidence includes reduced HIF-1α protein synthesis rather than exclusively altered transcription or degradation.
9	EMT invasion and extracellular-matrix remodeling	↑ E-cadherin ↓ N-cadherin ↓ vimentin ↓ MMP2 and MMP9 ↓ TGF-β signaling	Possible modulation of wound repair and fibrosis pathways	G	Reduced migration, invasion, and metastatic phenotype	Effects may involve tumor cells, macrophages, stromal signaling, and cancer-stem-cell maintenance.
10	Cancer stemness and differentiation state	↓ CD133 ↓ OCT4 ↓ NOTCH1 ↓ stem-cell formation	Effects on normal progenitor populations are insufficiently characterized	G	Reduced tumor initiation and recurrence-associated phenotype	Supported primarily by cell and animal models; clinically meaningful selectivity has not been established.
11	Autophagy ER stress and necroptosis	↑ autophagy ↑ ER stress or ↓ ER stress (model-dependent) ↑ RIP1 and MLKL signaling in selected models	Protective or toxic depending on tissue and exposure	R–G	Alternative stress-response and death pathways	Autophagy can facilitate death or survival. Necroptosis has been demonstrated in selected renal cancer models but should not be generalized.
12	NRF2 HO-1 antioxidant response	↑ NRF2 ↑ HO-1 (secondary; context-dependent)	↑ NRF2-mediated antioxidant and cytoprotective signaling	R–G	Compensatory antioxidant response	NRF2 activation may limit oxidative injury in normal tissues but could also reduce emodin cytotoxicity or support resistant cancer cells. It is not consistently the primary anticancer mechanism.
13	HDAC and chromatin regulation	↓ HDAC activity ↑ histone acetylation	Epigenetic modulation possible	R–G	Altered transcriptional state	Biochemical HDAC inhibition is reported, but the free concentrations required and its contribution in vivo remain uncertain.
14	Chemosensitization	↑ chemotherapy sensitivity ↓ survival and resistance pathways	Potential ↑ normal-tissue toxicity or altered drug disposition	G	Enhanced response to selected anticancer agents	Reported combinations are promising preclinically, but interactions cannot be assumed beneficial because emodin also affects metabolism, transport, redox balance, and normal-cell viability.
15	Clinical Translation Constraint	↓ free systemic exposure ↑ conjugated metabolites heterogeneous tumor response	Dose-limiting gastrointestinal and organ toxicity concerns	G	Limited translation of in-vitro activity	Approximately 3% oral bioavailability in rat studies, extensive glucuronidation and sulfation, poor solubility, short exposure, absence of validated clinical dosing, and lack of randomized oncology trials are major limitations.

P: 0–30 min R: 30 min–3 hr G: >3 hr

PARP, poly ADP-ribose polymerase (PARP) cleavage: Click to Expand ⟱

Source:

Type:

Poly (ADP-ribose) polymerase (PARP) cleavage is a hallmark of caspase activation. PARP (Poly (ADP-ribose) polymerase) is a family of proteins involved in a variety of cellular processes, including DNA repair, genomic stability, and programmed cell death. PARP enzymes play a crucial role in repairing single-strand breaks in DNA.
PARP has gained significant attention, particularly in the treatment of certain types of tumors, such as those with BRCA1 or BRCA2 mutations. These mutations impair the cell's ability to repair double-strand breaks in DNA through homologous recombination. Cancer cells with these mutations can become reliant on PARP for survival, making them particularly sensitive to PARP inhibitors.
PARP inhibitors, such as olaparib, rucaparib, and niraparib, have been developed as targeted therapies for cancers associated with BRCA mutations.

PARP Family:
The poly (ADP-ribose) polymerases (PARPs) are a family of enzymes involved in a number of cellular processes, including DNA repair, genomic stability, and programmed cell death.
PARP1 is the predominant family member responsible for detecting DNA strand breaks and initiating repair processes, especially through base excision repair (BER).

PARP1 Overexpression:
In several cancer types—including breast, ovarian, prostate, and lung cancers—elevated PARP1 expression and/or activity has been reported.
High PARP1 expression in certain cancers has been associated with aggressive tumor behavior and resistance to therapies (especially those that induce DNA damage).
Increased PARP1 activity may correlate with poorer overall survival in tumors that rely on DNA repair for survival.

Scientific Papers found: Click to Expand⟱

5223-

EMD,

Emodin inhibits colon cancer by altering BCL-2 family proteins and cell survival pathways

in-vitro,

CRC,

DLD1

in-vitro,

Nor,

CCD841

tumCV↓, Apoptosis↑, selectivity↑, Casp↑, Bcl-2↓, MMP↓, TumCD↑, MAPK↓, JNK↓, PI3K↓, Akt↓, NF-kB↓, STAT↓, Diff↓, P53↑, PARP↓,

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:

Drug Metabolism & Resistance(tgid=21) ⓘ

selectivity↑, 1,
Total Targets: 16

Pathway results for Effect on Normal Cells:

Total Targets: 0

Scientific Paper Hit Count for: PARP, poly ADP-ribose polymerase (PARP) cleavage

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#:75  Target#:239  State#:%  Dir#:1
  wNotes=0  sortOrder:rid,rpid

Emodin / PARP Cancer Research Results

Mechanistic Profile of Emodin

Pathway results for Effect on Cancer / Diseased Cells:

Mitochondria & Bioenergetics(tgid=3) ⓘ

Cell Death(tgid=5) ⓘ

Transcription & Epigenetics(tgid=7) ⓘ

DNA Damage & Repair(tgid=10) ⓘ

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

Immune & Inflammatory Signaling(tgid=16) ⓘ

Drug Metabolism & Resistance(tgid=21) ⓘ

Pathway results for Effect on Normal Cells:

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