Gambogic Acid / Proteasome Cancer Research Results

GamB, Gambogic Acid: Click to Expand ⟱
Features:
Gambogic acid is a naturally occurring xanthonoid extracted from the resin of trees belonging to the Garcinia genus—most notably, Garcinia hanburyi. This tree is native to regions in Southeast Asia, particularly found in areas of China, India, and neighboring countries.
Gambogic acid (GA; C38H44O8, MW: 628.76), a polyprenylated xanthone and a widely used coloring agent, is the main active ingredient of gamboges secreted from the Garcinia hanburyi tree ([3, 4], which mainly grows in Southeast Asia.
GA has been approved by the Chinese FDA for the treatment of solid cancers in Phase II clinical trials.

Pathways:
-evidence suggesting that it can inhibit thioredoxin reductase (TrxR).
-can indeed lead to an increase in reactive oxygen species (ROS) levels
-Gambogic acid can trigger mitochondrial dysfunction, leading to cytochrome c release
-influences death receptors
-Inhibition of NF-κB Signaling
-Inhibition of VEGF Pathway
-Cell Cycle Arrest:
-p53 Activation
Rank Pathway / Target Axis Direction Primary Effect Notes / Cancer Relevance Ref
1 Thioredoxin / Thioredoxin reductase (Trx / TrxR) ↓ Trx / TrxR activity Redox buffering collapse Primary molecular target; covalent cysteine interaction drives loss of antioxidant capacity (ref)
2 ROS accumulation ↑ ROS Oxidative stress overload Immediate consequence of Trx/TrxR inhibition; upstream of mitochondrial damage (ref)
3 Mitochondrial integrity (ΔΨm) ↓ ΔΨm Mitochondrial dysfunction GA reduces mitochondrial membrane potential prior to execution-phase death (ref)
4 Intrinsic apoptosis / pyroptosis (caspase-3, GSDME) ↑ programmed cell death Execution-phase killing Mitochondrial apoptosis and caspase-3/GSDME-dependent pyroptosis reported (ref)
5 NF-κB signaling ↓ NF-κB activation Reduced pro-survival transcription Redox-sensitive suppression of NF-κB nuclear activity and target genes (ref)
6 PI3K–AKT survival signaling ↓ AKT phosphorylation Survival pathway collapse Downstream of oxidative stress and chaperone disruption (ref)
7 HSP90 chaperone function ↓ client stabilization Oncoprotein destabilization GA disrupts HSP90–client interactions affecting AKT, HER2, etc. (ref)
8 ER stress / UPR ↑ ER stress signaling Proteotoxic stress Secondary ER stress response following redox and mitochondrial disruption (ref)
9 Cell cycle regulation ↑ cell-cycle arrest Proliferation blockade Checkpoint activation downstream of stress signaling (ref)
10 Autophagy (stress-induced) ↑ autophagy Adaptive or pro-death response Autophagy induction reported; role varies by context (ref)
11 Angiogenesis signaling (VEGF) ↓ VEGF expression Anti-angiogenic effect Suppression of pro-angiogenic transcription observed (ref)
12 Tumor growth in vivo ↓ tumor volume Integrated outcome Xenograft models show significant tumor growth inhibition (ref)


Proteasome, Proteasome: Click to Expand ⟱
Source: HalifaxProj (inhibit)
Type:
The proteasome is a crucial component of the cellular machinery responsible for degrading ubiquitinated proteins, which are proteins tagged for destruction. This process is essential for maintaining cellular homeostasis, regulating the cell cycle, and controlling various signaling pathways.
Many cancer cells exhibit increased expression of proteasome subunits. This upregulation can enhance the proteasome's capacity to degrade proteins, including those that regulate cell cycle progression and apoptosis, thereby promoting tumor growth and survival.

Proteasome inhibitors act by blocking the activity of the proteasome, a crucial cellular complex responsible for degrading most intracellular proteins.
-The proteasome is responsible for degrading ubiquitin-tagged proteins, including misfolded, damaged, or regulatory proteins. By inhibiting the proteasome’s function, these proteins accumulate within the cell.
-Accumulated proteins can lead to increased cellular stress, particularly in the endoplasmic reticulum (ER) where misfolded proteins build up. This stress can trigger the unfolded protein response (UPR), which, if unresolved, may lead to apoptosis (programmed cell death).
-It is well known that ROS plays an important role in proteasome inhibition-induced cell death.

Inhibitor Drugs: bortezomib (Velcade) and carfilzomib

Natural Product Inhibitors:
-Gambogic Acid:
-Lactacystin: Origin: Isolated from the bacterium Streptomyces lactacystinaeus.
-Epoxomicin is a highly selective and potent inhibitor of the proteasome. Its structure has informed the design of synthetic drugs such as carfilzomib.
-Syringolin A
-Tyropeptins
-EGCG
-Withania somnifera (commonly known as Ashwagandha).
-Celastrol
Origin: Derived from plants of the Tripterygium genus (commonly known as Thunder God Vine).
Scientific Papers found: Click to Expand⟱
1960- GamB,  Vem,    Calcium channel blocker verapamil accelerates gambogic acid-induced cytotoxicity via enhancing proteasome inhibition and ROS generation
- in-vitro, Liver, HepG2 - in-vitro, AML, K562
Proteasome↓, eff↑, Casp↑, ER Stress↑, ROS↑, eff↑,

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:


Redox & Oxidative Stress ⓘ

ROS↑, 1,  

Cell Death ⓘ

Casp↑, 1,   Proteasome↓, 1,  

Protein Folding & ER Stress ⓘ

ER Stress↑, 1,  

Drug Metabolism & Resistance ⓘ

eff↑, 2,  
Total Targets: 5

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: Proteasome, Proteasome
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#:302  Target#:262  State#:%  Dir#:%
  wNotes=0  sortOrder:rid,rpid

 

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