Germacranolide sesquiterpene lactone / Catalase Cancer Research Results

GSL, Germacranolide sesquiterpene lactone: Click to Expand ⟱
Features:
A germacranolide sesquiterpene lactone (GSL) was isolated from Siegesbeckia glabrescens

Germacranolide — Germacranolides are a structural subclass of plant-derived sesquiterpene lactones built on a ten-membered germacrane ring fused to a lactone moiety.

Primary mechanisms (ranked):

  1. Inhibition of Hedgehog effector signaling through suppression of GLI-mediated transcription, including reduced GLI1 expression.
  2. Suppression of cyclin D1 downstream of GLI, producing reduced proliferation of Hedgehog-dependent pancreatic cancer cells.
  3. Inhibition of inflammatory mediator production, including nitric oxide and prostaglandin E2, with reduced inducible nitric oxide synthase and cyclooxygenase-2 expression in activated macrophages.
  4. Electrophilic modification of protein thiols through the α-methylene-γ-lactone pharmacophore is a plausible class-level mechanism for many germacranolides, but direct target engagement has not been established for this specific S. glabrescens GSL.

Bioavailability / PK relevance: No compound-specific absorption, distribution, metabolism, excretion, plasma-exposure, or oral-bioavailability data were identified for the S. glabrescens GSL. Sesquiterpene lactones commonly have poor aqueous solubility, chemical reactivity, rapid metabolism, and nonspecific thiol binding that may limit systemic exposure and therapeutic index. Pharmacokinetic findings from geraniol, germacrone, costunolide, or other germacranolides should not be assigned to this compound.

In-vitro vs systemic exposure relevance: The anticancer experiments used approximately 1–20 µM GSL for transcriptional assays and up to 20 µM for protein analyses; reported proliferation IC50 values were approximately 5.1 µM in AsPC-1 cells and higher in nonmalignant C3H10T1/2 cells. Whether these concentrations are achievable or sustainable in humans is unknown because no human or animal systemic-exposure data were reported. The evidence is therefore concentration-driven and restricted principally to cell culture.

Clinical evidence status: Preclinical only. Evidence for the specific S. glabrescens GSL consists primarily of biochemical and cell-culture studies in pancreatic cancer cells, mesenchymal reporter cells, and activated macrophages. No clinical trials, approved indications, validated dosing regimen, or human anticancer efficacy data were identified. Other germacranolides have broader preclinical anticancer literature, but that evidence cannot be generalized directly to this compound.

Mechanistic Profile

Rank Pathway / Axis Cancer Cells Normal Cells TSF Primary Effect Notes / Interpretation
1 Hedgehog GLI transcription ↓ GLI transcriptional activity
↓ GLI1		 ↓ Shh-induced differentiation signaling in C3H10T1/2 cells R–G Suppresses the terminal transcriptional output of Hedgehog signaling Central demonstrated mechanism. Activity was observed in GLI reporter systems and PANC-1 and AsPC-1 pancreatic cancer cells. The precise molecular binding target upstream of GLI remains unidentified.
2 Cyclin D1 cell-cycle signaling ↓ cyclin D1
↓ proliferation		 ↔ or less sensitive (model-dependent) G Restricts proliferative cell-cycle progression Cyclin D1 reduction is consistent with inhibition of GLI-dependent transcription. Formal phase-specific arrest was not comprehensively characterized.
3 Pancreatic cancer cell viability ↓ PANC-1 proliferation
↓ AsPC-1 proliferation		 ↓ at higher concentrations G Concentration-dependent antiproliferative activity AsPC-1 cells showed an IC50 near 5 µM, whereas C3H10T1/2 cells were less sensitive. Selectivity remains preliminary and was not established in vivo.
4 Inflammatory nitric oxide signaling Not adequately established ↓ nitric oxide
↓ inducible nitric oxide synthase (context-dependent)		 G Reduces macrophage inflammatory mediator production Demonstrated in LPS-activated RAW264.7 macrophages. This is an anti-inflammatory finding and should not automatically be interpreted as an anticancer mechanism.
5 Prostaglandin E2 and cyclooxygenase-2 Not demonstrated for the specific compound ↓ prostaglandin E2
↓ cyclooxygenase-2 (context-dependent)		 G Suppresses inflammatory prostaglandin synthesis The Nestronics COX-2 entry is supportable through the macrophage study, but not through the listed rosmarinic acid and ginsenoside Rg1 paper.
6 PI3K AKT signaling ↔ phosphorylated AKT and total AKT Not established R–G No detected modulation under the tested conditions Supports a GLI-directed effect that was independent of measurable AKT suppression in PANC-1 cells.
7 Electrophilic thiol reactivity Potential covalent protein modulation (context-dependent) Potential off-target protein binding and sensitization P–R Class-level Michael-acceptor activity The α-methylene-γ-lactone group can react with cysteine thiols. This may contribute to biological activity but also creates selectivity and toxicity constraints. Direct protein targets have not been confirmed for this GSL.
8 Clinical Translation Constraint In-vitro activity only Human safety unknown G Uncertain systemic feasibility No compound-specific PK, formulation, animal efficacy, clinical trial, or therapeutic dose data. Poor solubility, reactive electrophilicity, and possible sesquiterpene-lactone hypersensitivity are relevant class concerns.

P: 0–30 min    R: 30 min–3 hr    G: >3 hr
Catalase, Catalase: Click to Expand ⟱
Source:
Type:
Caspases are a cysteine protease that speed up a chemical reaction via pointing their target substrates following an aspartic acid residue.1 They are grouped into apoptotic (caspase-2, 3, 6, 7, 8, 9 and 10) and inflammatory (caspase-1, 4, 5, 11 and 12) mediated caspases.
Caspase-1 may have both tumorigenic or antitumorigenic effects on cancer development and progression, but it depends on the type of inflammasome, methodology, and cancer.
Catalase is an enzyme found in nearly all living cells exposed to oxygen. Its primary role is to protect cells from oxidative damage by catalyzing the conversion of hydrogen peroxide (H₂O₂), a potentially damaging byproduct of metabolism, into water (H₂O) and oxygen (O₂). This detoxification process is crucial because excess H₂O₂ can lead to the formation of reactive oxygen species (ROS) that damage proteins, lipids, and DNA.

Catalase and Cancer
Oxidative Stress and Cancer:
Cancer cells often experience increased levels of oxidative stress due to rapid proliferation and metabolic changes. This stress can lead to DNA damage, promoting tumorigenesis.
Catalase helps mitigate oxidative stress, and its expression can influence the survival and proliferation of cancer cells.
Expression Levels in Different Cancers:
Overexpression: In some cancers, such as breast cancer and certain types of leukemia, catalase may be overexpressed. This overexpression can help cancer cells survive in oxidative environments, potentially leading to more aggressive tumor behavior.
Downregulation: Conversely, in other cancers, such as colorectal cancer, reduced catalase expression has been observed. This downregulation can lead to increased oxidative stress, contributing to tumor progression and metastasis.
Prognostic Implications:
Survival Rates: Studies have shown that high levels of catalase expression can be associated with poor prognosis in certain cancers, as it may enable cancer cells to resist apoptosis (programmed cell death) induced by oxidative stress.

Some types of cancer cells have been reported to exhibit lower catalase activity, possibly increasing their vulnerability to oxidative damage under certain conditions. This vulnerability has even been exploited in some therapeutic strategies (for example, approaches that generate excess H₂O₂ or other ROS specifically targeting cancer cells have been researched).
Scientific Papers found: Click to Expand⟱
6561- GSL,    Geraniol Pharmacokinetics, Bioavailability and Its Multiple Effects on the Liver Antioxidant and Xenobiotic-Metabolizing Enzymes
- in-vivo, Nor, NA
*Inflam↓, *antiOx↑, *neuroP↑, *AntiCan↑, *BioAv↝, *Dose↝, *toxicity↓, *Catalase↑, *NADPH↑, *GSR↑, *ALAT∅, *AST∅,

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:


Total Targets: 0

Pathway results for Effect on Normal Cells:


Redox & Oxidative Stress(tgid=1) ⓘ

antiOx↑, 1,   Catalase↑, 1,   GSR↑, 1,  

Core Metabolism/Glycolysis(tgid=4) ⓘ

ALAT∅, 1,   NADPH↑, 1,  

Immune & Inflammatory Signaling(tgid=16) ⓘ

Inflam↓, 1,  

Drug Metabolism & Resistance(tgid=21) ⓘ

BioAv↝, 1,   Dose↝, 1,  

Clinical Biomarkers(tgid=22) ⓘ

ALAT∅, 1,   AST∅, 1,  

Functional Outcomes(tgid=23) ⓘ

AntiCan↑, 1,   neuroP↑, 1,   toxicity↓, 1,  
Total Targets: 13

Scientific Paper Hit Count for: Catalase, Catalase
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#:86  Target#:46  State#:%  Dir#:%
  wNotes=0  sortOrder:rid,rpid

 

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