5-Aminolevulinic acid / toxicity Cancer Research Results

5-ALA, 5-Aminolevulinic acid: Click to Expand ⟱
Features:
Aminolevulinic acid (5-ALA) is primarily known for its role as a biosynthetic precursor to heme

5-ALA — 5-aminolevulinic acid (5-aminolevulinic acid; often administered as the hydrochloride salt) is an endogenous, small-molecule heme biosynthesis precursor used clinically as a pro-photosensitizer for tumor visualization and, when paired with an appropriate light source, photodynamic therapy (PDT). It is formally a drug/prodrug modality whose functional identity is to drive intracellular accumulation of the fluorescent porphyrin protoporphyrin IX (PpIX), enabling fluorescence-guided resection (notably high-grade glioma) and light-activated cytotoxicity in appropriately illuminated tissues. Standard abbreviations include 5-ALA, ALA; the key active photochemical mediator is PpIX. Tumor selectivity is primarily metabolic (differential porphyrin/heme pathway handling), rather than target-receptor binding, and clinical performance is strongly constrained by light penetration and local oxygen availability.

Primary mechanisms (ranked):

  1. Heme biosynthesis precursor loading causing preferential intracellular PpIX accumulation and fluorescence in many tumor/preneoplastic tissues
  2. Light-activated PpIX photochemistry generating ROS (notably singlet oxygen) and acute oxidative injury
  3. Mitochondrial damage and cell-death execution (apoptosis/necrosis; can include MPTP involvement) after photostress
  4. Local vascular injury and microenvironment collapse (perfusion impairment; oxygen- and geometry-dependent)
  5. Inflammatory / immunogenic cell-death signaling and downstream immune modulation (context-dependent)

Bioavailability / PK relevance: Route-locked. Oral ALA-HCl is used for intraoperative fluorescence in glioma with timed dosing prior to anesthesia/surgery; topical formulations are used for dermatologic PDT with local incubation followed by office-based illumination. Systemic exposure is clinically relevant for oral use (and photosensitivity risk), while topical use is primarily local with workflow defined by incubation + illumination.

In-vitro vs systemic exposure relevance: Many “dark” in-vitro ALA studies use concentrations that are not directly exposure-matched to clinical plasma levels; the clinically dominant cytotoxic mechanism is typically light-triggered, PpIX-mediated photochemistry rather than concentration-only pharmacology.

Clinical evidence status: Established clinical deployment as an adjunct optical imaging agent for fluorescence-guided resection of suspected high-grade glioma (approved) and as a photosensitizer precursor for dermatologic PDT (approved for actinic keratosis; additional indications vary by jurisdiction). Oncology PDT applications beyond these settings are heterogeneous and commonly investigational or center-specific.

-ALA is used in medical therapies such as photodynamic therapy (PDT) for certain types of cancer and skin conditions.
- Inside the cells, ALA enters the heme biosynthetic pathway and is converted to protoporphyrin IX (PpIX), a potent photosensitizer.
-The light activates the accumulated PpIX, leading to the production of reactive oxygen species (ROS).
-FDA approved June 2017 as a photo-imaging tool during neurosurgery for malignant glioma. The patient takes an oral dose of Gleolan 3 hours before surgery.

Mechanistic pathway ranking for 5-ALA (oncology focus)

Rank Pathway / Axis Cancer Cells Normal Cells TSF Primary Effect Notes / Interpretation
1 Heme biosynthesis loading to PpIX accumulation ↑ PpIX (often higher and more spatially heterogeneous) ↑ PpIX (typically lower; tissue-dependent) R Fluorescence contrast prerequisite for PDD/FGS and PDT substrate formation Tumor selectivity is largely metabolic (porphyrin pathway flux, transporter expression, ferrochelatase activity, iron availability); not a receptor-targeted drug in the classic sense.
2 ROS photogeneration by excited PpIX ↑ ROS (requires light + O₂) ↑ ROS (requires light + O₂) P Type II (singlet oxygen) and Type I oxidative damage driving phototoxicity This is the dominant “killing” lever for PDT; absent illumination, ROS burst is not the main mode.
3 Mitochondria / MPTP ↓ mitochondrial function; ↑ MPTP (context-dependent) ↓ mitochondrial function; ↑ MPTP (context-dependent) P Energetic collapse and amplification of cell-death signaling PpIX can localize to mitochondria in many settings; mitochondrial photodamage is a common execution node for PDT.
4 Cell-death programs ↑ apoptosis/necrosis (dose-dependent) ↑ apoptosis/necrosis (dose-dependent) R Tumor cell kill and lesion clearance Phenotype depends on light dose-rate, oxygenation, subcellular PpIX localization, and baseline stress defenses.
5 Vascular injury and perfusion failure ↓ perfusion (context-dependent) ↓ perfusion (context-dependent) R Secondary tumor control via microvascular damage Most relevant in vivo; magnitude depends on illumination geometry and local vascular photosensitization.
6 NRF2 antioxidant stress response ↑ NRF2 programs (context-dependent) ↑ NRF2 programs (context-dependent) G Adaptive resistance to oxidative photostress Often a downstream consequence of photodynamic redox stress; clinically relevant as a resistance axis in repeat/low-dose contexts.
7 Iron handling and ferrochelatase constraint ↓ ferrochelatase constraint can yield ↑ PpIX (model-dependent) Variable R Controls PpIX-to-heme conversion and thus fluorescence/phototoxic substrate levels Iron availability and heme-pathway enzyme balance can shift PpIX accumulation; a key reason for inter-tumor variability.
8 Chemosensitization or Radiosensitization ↑ sensitivity (context-dependent) Variable R Combination leverage via oxidative injury and stress overload Evidence is indication- and protocol-specific; synergy is plausible but not universal and can be limited by light/oxygen constraints.
9 Clinical Translation Constraint Depth-limited light delivery; oxygen dependence; heterogeneous PpIX; workflow timing; photosensitivity risk; tissue-selective illumination required — Defines where 5-ALA is clinically practical For most solid tumors, light penetration and geometry (and local O₂) are the hard constraints; these often dominate over “molecular pathway” considerations.


toxicity, toxicity: Click to Expand ⟱
Source:
Type:
Toxicity
Scientific Papers found: Click to Expand⟱
2582- ART/DHA,  5-ALA,    Mechanistic Investigation of the Specific Anticancer Property of Artemisinin and Its Combination with Aminolevulinic Acid for Enhanced Anticolorectal Cancer Activity
- in-vivo, CRC, HCT116 - in-vitro, CRC, HCT116
eff↑, ROS↑, selectivity↑, TumCG↓, toxicity↓,

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,  

Proliferation, Differentiation & Cell State ⓘ

TumCG↓, 1,  

Drug Metabolism & Resistance ⓘ

eff↑, 1,   selectivity↑, 1,  

Functional Outcomes ⓘ

toxicity↓, 1,  
Total Targets: 5

Pathway results for Effect on Normal Cells:


Total Targets: 0

Scientific Paper Hit Count for: toxicity, toxicity
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#:332  Target#:1025  State#:%  Dir#:1
  wNotes=0  sortOrder:rid,rpid

 

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