Description: <b>Betulinic acid</b> "buh-TOO-li-nik acid" is a natural compound with antiretroviral, anti malarial, anti-inflammatory and anticancer properties. It is found in the bark of several plants, such as white birch, ber tree and rosemary, and has a complex mode of action against tumor cells.<br>
-Betulinic acid is a naturally occurring pentacyclic triterpenoid<br>
-vitro concentrations range from 1–100 µM, in vivo studies in rodents have generally used doses from 10–100 mg/kg<br>
Precursor: Betulin, via oxidation at C-28<br>
Lipophilicity: High (poor aqueous solubility)<br>
<p><b>Betulinic acid</b> — Betulinic acid is a naturally occurring lupane-type pentacyclic triterpenoid with broad experimental anticancer activity, especially against melanoma, neuroectodermal, glioma, breast, colorectal, and other solid-tumor models. It is a natural-product small molecule, usually abbreviated BA or BetA, and is found in several plants, classically birch bark, with semi-synthesis commonly starting from betulin. A distinguishing feature is preferential induction of tumor-cell death through direct mitochondrial injury with relative sparing of many non-neoplastic cells in preclinical systems. Its main translational limitation is very poor aqueous solubility with correspondingly weak oral/systemic developability unless formulation or derivatization is used.</p>
<p><b>Primary mechanisms (ranked):</b></p>
<ol>
<li>Direct mitochondrial membrane permeabilization with intrinsic apoptosis activation</li>
<li>Mitochondrial ROS increase with collapse of mitochondrial membrane potential and cytochrome c release</li>
<li>ER-stress and unfolded-protein-response activation, including GRP78-linked stress signaling</li>
<li>Suppression of NF-κB and other pro-survival transcriptional programs, including Sp-family signaling in some models</li>
<li>Cell-cycle arrest with reduced cyclin/CDK signaling</li>
<li>Anti-migratory and anti-invasive effects via EMT, FAK, ROCK1, MMP, and cytoskeletal remodeling pathways</li>
<li>Secondary metabolic suppression of aerobic glycolysis and hypoxia-response signaling in susceptible models</li>
<li>Adjunct sensitization to chemo- or radiotherapy in selected preclinical settings</li>
</ol>
<p><b>Bioavailability / PK relevance:</b> Betulinic acid is highly lipophilic and poorly water-soluble, which strongly limits oral absorption and systemic exposure. PK behavior is formulation-dependent, and much of the translational literature focuses on nanoparticles, liposomes, micelles, conjugates, or topical delivery rather than conventional oral dosing.</p>
<p><b>In-vitro vs systemic exposure relevance:</b> Many in-vitro anticancer studies use low-to-mid micromolar concentrations, which are often difficult to reproduce reliably in vivo with unformulated parent betulinic acid. Accordingly, mechanistic findings are useful biologically, but direct concentration matching to standard oral/systemic use is often poor unless enhanced-delivery systems are used.</p>
<p><b>Clinical evidence status:</b> Strong preclinical and formulation-development literature; very limited human oncology evidence. Cancer-facing clinical development appears to remain early-phase/topical, with orphan designation for topical metastatic melanoma but no FDA approval for that indication. Betulinic acid itself is not an established approved anticancer drug.</p>
-<a href="tbResList.php?qv=42&tsv=1109&wNotes=on&exSp=open">half-life</a> reports vary 3-5 hrs?.
Reported half-life varies by formulation and species; several studies report multi-hour systemic persistence.<br>
<a href="tbResList.php?qv=42&tsv=792&wNotes=on&exSp=open">BioAv</a> -hydrophobic molecule with relatively poor water solubility. <br>
<pre>
Main Cancer action
-Direct mitochondrial targeting in cancer cells
-Minimal effect on normal cells
Key pathways
-Mitochondrial membrane permeabilization
-ROS-mediated apoptosis
-Caspase-independent death
Chemo relevance: Generally compatible, Not a redox buffer
</pre>
<br>
Pathways:<br>
<!-- ROS : MMP↓, ER Stress↑, Ca+2↑, Cyt‑c↑, Casp3↑, Casp9↑, DNAdam↑, UPR↑, cl-PARP↑-->
- often induce
<a href="tbResList.php?qv=42&tsv=275&wNotes=on">ROS</a> production<br>
- ROS↑ related:
<a href="tbResList.php?&qv=42&tsv=197&wNotes=on&word=MMP↓">MMP↓</a>(ΔΨm),
<a href="tbResList.php?&qv=42&tsv=103&wNotes=on">ER Stress↑</a>,
<a href="tbResList.php?&qv=42&tsv=459&wNotes=on">UPR↑</a>,
<a href="tbResList.php?&qv=42&tsv=356&wNotes=on">GRP78↑</a>,
<a href="tbResList.php?&qv=42&tsv=38&wNotes=on&word=Ca+2↑">Ca+2↑</a>,
<a href="tbResList.php?&qv=42&tsv=77&wNotes=on">Cyt‑c↑</a>,
<a href="tbResList.php?&qv=42&wNotes=on&word=Casp">Caspases↑</a>,
<a href="tbResList.php?&qv=42&tsv=82&wNotes=on&word=DNAdam↑">DNA damage↑</a>,
<a href="tbResList.php?&qv=42&tsv=239&wNotes=on">cl-PARP↑</a>,
<a href="tbResList.php?&qv=42&wNotes=on&word=HSP">HSP↓</a>
<br>
<!-- ANTIOXIDANT : NRF2, SOD, GSH, CAT, HO-1, GPx, GPX4, -->
- Lowers AntiOxidant defense in Cancer Cells(Often associated with reduced redox buffering capacity in tumor cells (e.g., GSH depletion); NRF2 direction model-dependent.):
<a href="tbResList.php?&qv=42&tsv=226&wNotes=on&word=NRF2↓">NRF2↓</a>,
<a href="tbResList.php?&qv=42&tsv=298&wNotes=on&word=SOD↓">SOD↓</a>,
<a href="tbResList.php?&qv=42&tsv=137&wNotes=on&word=GSH↓">GSH↓</a>
<br>
- May Raise
<a href="tbResList.php?&qv=42&tsv=1103&wNotes=on&word=antiOx↑">AntiOxidant</a>
defense in Normal Cells:
<a href="tbResList.php?&qv=42&tsv=226&wNotes=on&word=NRF2↑">NRF2↑</a>,
<a href="tbResList.php?&qv=42&tsv=298&wNotes=on&word=SOD↑">SOD↑</a>,
<a href="tbResList.php?&qv=42&tsv=137&wNotes=on&word=GSH↑">GSH↑</a>,
<a href="tbResList.php?&qv=42&tsv=46&wNotes=on&word=Catalase↑">Catalase↑</a>
Reports suggest relative sparing of normal cells and preservation of antioxidant capacity in some models
<br>
<!-- INFLAMMATION : NF-kB↓, COX2↓, COX2↓ PRO-INFL CYTOKINES: IL-1β↓, TNF-α↓, IL-6↓, IL-8↓, -->
- lowers
<a href="tbResList.php?&qv=42&tsv=953&wNotes=on&word=Inflam">Inflammation</a> :
<a href="tbResList.php?&qv=42&tsv=214&wNotes=on&word=NF-kB↓">NF-kB↓</a>(typ),
<a href="tbResList.php?&qv=42&tsv=66&wNotes=on&word=COX2↓">COX2↓</a>,
<a href="tbResList.php?&qv=42&tsv=235&wNotes=on&word=p38↓">p38↓</a>
(context-dependent; often stress-activated), Pro-Inflammatory Cytokines :
<a href="tbResList.php?&qv=42&tsv=978&wNotes=on&word=IL1β↓">IL-1β↓</a>,
<a href="tbResList.php?&qv=42&tsv=309&wNotes=on&word=TNF-α↓">TNF-α↓</a>,
<a href="tbResList.php?&qv=42&tsv=158&wNotes=on&word=IL6↓">IL-6↓</a>,
<a href="tbResList.php?&qv=42&tsv=368&wNotes=on&word=IL8↓">IL-8↓</a>
<br>
<!-- GROWTH/METASTASES : EMT↓, MMPs↓, MMP2↓, MMP9↓, IGF-1, uPA↓, VEGF↓, ERK↓
inhibiting metastasis-associated proteins such as ROCK1, FAK, (RhoA), NF-κB and u-PA, MMP-1 and MMP-13.-->
- inhibit Growth/Metastases :
<a href="tbResList.php?&qv=42&tsv=96&wNotes=on"EMT↓</a>,
<a href="tbResList.php?&qv=42&tsv=204&wNotes=on">MMPs↓</a>,
<a href="tbResList.php?&qv=42&tsv=201&wNotes=on">MMP2↓</a>,
<a href="tbResList.php?&qv=42&tsv=203&wNotes=on">MMP9↓</a>,
<a href="tbResList.php?&qv=42&tsv=308&wNotes=on">TIMP2</a>,
<a href="tbResList.php?&qv=42&tsv=415&wNotes=on">IGF-1↓</a>,
<a href="tbResList.php?&qv=42&tsv=334&wNotes=on">VEGF↓</a>,
<a href="tbResList.php?&qv=42&tsv=1284&wNotes=on">ROCK1↓</a>,
<a href="tbResList.php?&qv=42&tsv=110&wNotes=on">FAK↓</a>,
<a href="tbResList.php?&qv=42&tsv=214&wNotes=on">NF-κB↓</a>,
<a href="tbResList.php?&qv=42&tsv=304&wNotes=on">TGF-β↓</a>,
<a href="tbResList.php?&qv=42&tsv=719&wNotes=on">α-SMA↓</a>,
<a href="tbResList.php?&qv=42&tsv=105&wNotes=on">ERK↓</a>
<br>
<!-- REACTIVATE GENES : HDAC↓, DNMT1↓, DNMT3A↓, EZH2↓, P53↑, -->
- reactivate genes thereby inhibiting cancer cell growth :
<a href="tbResList.php?qv=42&tsv=236&wNotes=on">P53↑</a>,
<a href="tbResList.php?&qv=42&wNotes=on&word=HSP">HSP↓</a>(model-dependent),
<a href="tbResList.php?&qv=42&tsv=506&wNotes=on">Sp proteins↓</a>,
<br>
<!-- CELL CYCLE ARREST : TumCCA↑, cyclin D1↓, cyclin E↓, CDK2↓, CDK4↓, CDK6↓ -->
- cause Cell cycle arrest :
<a href="tbResList.php?&qv=42&tsv=322&wNotes=on">TumCCA↑</a>,
<a href="tbResList.php?&qv=42&tsv=73&wNotes=on">cyclin D1↓</a>,
<a href="tbResList.php?&qv=42&tsv=467&wNotes=on">CDK2↓</a>,
<a href="tbResList.php?&qv=42&tsv=894&wNotes=on">CDK4↓</a>,
<br>
<!-- MIGRATION/INVASION : TumCMig↓, TumCI↓, FAK↓, ERK↓, -->
- inhibits Migration/Invasion :
<a href="tbResList.php?&qv=42&tsv=326&wNotes=on">TumCMig↓</a>,
<a href="tbResList.php?&qv=42&tsv=324&wNotes=on">TumCI↓</a>,
<a href="tbResList.php?&qv=42&tsv=110&wNotes=on">FAK↓</a>,
<a href="tbResList.php?&qv=42&tsv=105&wNotes=on">ERK↓</a>,
<a href="tbResList.php?&qv=42&tsv=96&wNotes=on">EMT↓</a>,
<a href="tbResList.php?&qv=42&tsv=1117&wNotes=on">TOP1↓</a>,
<br>
<!-- GLYCOLYSIS : ATP↓, HIF-1α↓, PKM2↓, cMyc↓, PDK1↓, GLUT1↓, LDHA↓, HK2↓, Glucose↓, GlucoseCon↓, lactateProd, OXPHOS -->
- inhibits
<a href="tbResList.php?qv=42&tsv=129&wNotes=on">glycolysis</a>
(secondary to mitochondrial stress)
<a href="tbResList.php?qv=42&tsv=21&wNotes=on&word=ATP↓">ATP depletion</a> :
<a href="tbResList.php?&qv=42&tsv=143&wNotes=on">HIF-1α↓</a>,
<a href="tbResList.php?&qv=42&tsv=772&wNotes=on">PKM2↓</a>,
<a href="tbResList.php?&qv=42&tsv=35&wNotes=on">cMyc↓</a>,
<a href="tbResList.php?&qv=42&tsv=566&wNotes=on&word=GLUT">GLUT1↓</a>,
<a href="tbResList.php?&qv=42&tsv=906&wNotes=on">LDH↓</a>,
<a href="tbResList.php?&qv=42&tsv=175&wNotes=on&word=LDH">LDHA↓</a>,
<a href="tbResList.php?&qv=42&tsv=773&wNotes=on">HK2↓</a>,
<a href="tbResList.php?&qv=42&wNotes=on&word=PFK">PFKs↓</a>,
<a href="tbResList.php?&qv=42&wNotes=on&word=PDK">PDKs↓</a>,
<a href="tbResList.php?&qv=42&tsv=773&wNotes=on">HK2↓</a>,
<a href="tbResList.php?&qv=42&tsv=847&wNotes=on">ECAR↓</a>,
<a href="tbResList.php?&qv=42&tsv=356&wNotes=on">GRP78↑</a>(ER stress),
<a href="tbResList.php?&qv=42&tsv=623&wNotes=on">GlucoseCon↓</a>
<br>
<!-- ANGIOGENESIS : VEGF↓, VEGFR2↓, HIF-1α↓, NOTCH↓, FGF↓, PDGF↓, EGFR↓ ITG(Integrins↓)-->
- inhibits
<a href="tbResList.php?qv=42&tsv=447&wNotes=on">angiogenesis↓</a> :
<a href="tbResList.php?qv=42&tsv=334&wNotes=on">VEGF↓</a>,
<a href="tbResList.php?&qv=42&tsv=143&wNotes=on">HIF-1α↓</a>,
<a href="tbResList.php?&qv=42&tsv=94&wNotes=on&word=EGFR↓">EGFR↓</a>,
<br>
<!-- CSCs : CSC↓, CK2↓, Hh↓, GLi↓, GLi1↓, -->
- inhibits Cancer Stem Cells in some studies :
<a href="tbResList.php?qv=42&tsv=795&wNotes=on">CSC↓</a>,
<a href="tbResList.php?qv=42&tsv=124&wNotes=on">GLi1↓</a>,
<a href="tbResList.php?qv=42&tsv=342&wNotes=on">β-catenin↓</a>,
<a href="tbResList.php?qv=42&tsv=508&wNotes=on">OCT4↓</a>,
<br>
<!-- OTHERS : -->
- Others: <a href="tbResList.php?qv=42&tsv=252&wNotes=on">PI3K↓</a>(typ),
<a href="tbResList.php?qv=42&tsv=4&wNotes=on">AKT↓</a>(typ),
<a href="tbResList.php?qv=42&wNotes=on&word=JAK">JAK↓</a>,
<a href="tbResList.php?qv=42&wNotes=on&word=STAT">STAT↓</a>,
<a href="tbResList.php?qv=42&tsv=342&wNotes=on">β-catenin↓</a>,
<a href="tbResList.php?qv=42&tsv=9&wNotes=on">AMPK↓</a>(AMPK is often activated during metabolic stress),
<a href="tbResList.php?qv=42&tsv=105&wNotes=on">ERK↓</a>,
<a href="tbResList.php?qv=42&tsv=168&wNotes=on">JNK</a>,
<br>
<!-- SYNERGIES : -->
- Synergies:
<a href="tbResList.php?qv=42&tsv=1106&wNotes=on">chemo-sensitization</a>,
<a href="tbResList.php?qv=42&tsv=1171&wNotes=on">chemoProtective</a>,
<a href="tbResList.php?qv=42&tsv=1107&wNotes=on">RadioSensitizer</a>,
<a href="tbResList.php?qv=42&tsv=961&esv=2&wNotes=on&exSp=open">Others(review target notes)</a>,
<a href="tbResList.php?qv=42&tsv=1105&wNotes=on">Neuroprotective</a>,
<a href="tbResList.php?qv=42&tsv=557&wNotes=on">Cognitive</a>,
<a href="tbResList.php?qv=42&tsv=1175&wNotes=on">Renoprotection</a>,
<a href="tbResList.php?qv=42&tsv=1179&wNotes=on">Hepatoprotective</a>,
<a href="tbResList.php?&qv=42&tsv=1188&wNotes=on">CardioProtective</a>,
<br>
<!-- SELECTIVE: -->
- Selectivity:
<a href="tbResList.php?qv=42&tsv=1110&wNotes=on">Cancer Cells vs Normal Cells</a>
<br>
<br>
<h3>Mechanistic profile</h3>
<table>
<thead>
<tr>
<th>Rank</th>
<th>Pathway / Axis</th>
<th>Cancer Cells</th>
<th>Normal Cells</th>
<th>TSF</th>
<th>Primary Effect</th>
<th>Notes / Interpretation</th>
</tr>
</thead>
<tbody>
<tr>
<td>1</td>
<td>Mitochondrial permeabilization</td>
<td>↑ MOMP, ↓ ΔΨm, ↑ cytochrome c release, ↑ apoptosis</td>
<td>↔ / milder effect</td>
<td>P-R</td>
<td>Core tumor-selective death trigger</td>
<td>Best-supported central mechanism; helps explain activity in apoptosis-competent but therapy-resistant tumors.</td>
</tr>
<tr>
<td>2</td>
<td>Mitochondrial ROS increase</td>
<td>↑ ROS</td>
<td>↔ / possible antioxidant sparing (context-dependent)</td>
<td>P-R</td>
<td>Amplifies mitochondrial stress and death signaling</td>
<td>ROS appears mechanistically relevant in many tumor models, but not every study makes it the dominant initiating event.</td>
</tr>
<tr>
<td>3</td>
<td>Caspase axis and caspase-independent death</td>
<td>↑ caspase-9, ↑ caspase-3, ↑ PARP cleavage; caspase-independent death also reported</td>
<td>↔</td>
<td>R-G</td>
<td>Executes apoptosis after mitochondrial injury</td>
<td>BA can still kill some tumor cells when classical caspase execution is partly blocked, indicating non-canonical death contribution.</td>
</tr>
<tr>
<td>4</td>
<td>ER stress / UPR / GRP78</td>
<td>↑ ER stress, ↑ UPR, ↑ GRP78 stress signaling</td>
<td>↔</td>
<td>R-G</td>
<td>Links proteostatic stress to apoptosis and metastasis suppression</td>
<td>Especially relevant in breast and gastric cancer models; may also connect to metabolic suppression and chemosensitization.</td>
</tr>
<tr>
<td>5</td>
<td>NF-κB survival signaling</td>
<td>↓ NF-κB</td>
<td>↔ / ↓ inflammatory tone</td>
<td>R-G</td>
<td>Reduces survival, inflammatory, and resistance programs</td>
<td>Common downstream convergence node across several tumor types.</td>
</tr>
<tr>
<td>6</td>
<td>Cell-cycle machinery</td>
<td>↓ cyclin D1, ↓ CDK2, ↓ CDK4, ↑ cell-cycle arrest</td>
<td>↔</td>
<td>G</td>
<td>Slows proliferation</td>
<td>Usually supportive rather than primary; often follows stress and survival-pathway disruption.</td>
</tr>
<tr>
<td>7</td>
<td>EMT / invasion / matrix remodeling</td>
<td>↓ EMT, ↓ FAK, ↓ ROCK1, ↓ MMP2, ↓ MMP9, ↓ migration, ↓ invasion</td>
<td>↔</td>
<td>G</td>
<td>Antimetastatic effect</td>
<td>Consistent with reduced motility and invasive phenotype in multiple solid-tumor models.</td>
</tr>
<tr>
<td>8</td>
<td>Glycolysis</td>
<td>↓ glucose uptake, ↓ lactate, ↓ ECAR, ↓ HK2, ↓ PKM2, ↓ LDHA</td>
<td>↔</td>
<td>G</td>
<td>Secondary metabolic suppression</td>
<td>Not the universal initiating mechanism; appears important in selected breast-cancer and GRP78-linked systems.</td>
</tr>
<tr>
<td>9</td>
<td>HIF-1α hypoxia axis</td>
<td>↓ HIF-1α, ↓ VEGF, ↓ GLUT1, ↓ PDK1</td>
<td>↔</td>
<td>G</td>
<td>Reduces hypoxic adaptation and angiogenic drive</td>
<td>Relevant in hypoxic tumor biology and helps explain antiangiogenic/metabolic effects in some models.</td>
</tr>
<tr>
<td>10</td>
<td>NRF2 / antioxidant buffering</td>
<td>↓ NRF2 or ↓ redox buffering (model-dependent)</td>
<td>↔ / possible preservation of antioxidant tone (context-dependent)</td>
<td>R-G</td>
<td>May widen tumor redox vulnerability</td>
<td>Direction is not uniform across all models; safer to treat this as contextual rather than universally core.</td>
</tr>
<tr>
<td>11</td>
<td>Ca²⁺ stress</td>
<td>↑ Ca²⁺ (context-dependent)</td>
<td>↔</td>
<td>P-R</td>
<td>Supports organelle stress and apoptotic signaling</td>
<td>Usually part of the broader mitochondrial/ER stress network rather than a stand-alone primary target.</td>
</tr>
<tr>
<td>12</td>
<td>Radiosensitization or Chemosensitization</td>
<td>↑ sensitivity to radiation or selected drugs</td>
<td>Unclear</td>
<td>G</td>
<td>Adjunct leverage</td>
<td>Preclinical evidence supports additive or sensitizing effects with irradiation and with some chemotherapy settings, but this is not yet clinically established.</td>
</tr>
<tr>
<td>13</td>
<td>Clinical Translation Constraint</td>
<td>Poor solubility and limited systemic exposure constrain reproducibility</td>
<td>Same formulation constraint</td>
<td>G</td>
<td>Delivery bottleneck</td>
<td>Main barrier is not lack of mechanistic richness but drug-like exposure; translation currently depends heavily on formulation, derivatization, or topical/local use.</td>
</tr>
</tbody>
</table>
<p><b>Time-Scale Flag (TSF):</b> P / R / G</p>
<ul>
<li><b>P</b>: 0–30 min (primary/physical-chemical effects; rapid kinase/redox signaling)</li>
<li><b>R</b>: 30 min–3 hr (acute redox and stress-response activation)</li>
<li><b>G</b>: >3 hr (gene-regulatory adaptation and phenotypic outcomes)</li>
</ul>