Description: <b>Cannabidiol (CBD)</b> is a cannabinoid compound found in cannabis plants.<br>
Cannabidiol (CBD) is a non-psychoactive phytocannabinoid derived from Cannabis sativa that has drawn interest for its potential anticancer properties. <br>
Pathways:<br>
-Mitochondrial dysfunction, with loss of membrane potential leading to the release of cytochrome c and activation of caspase cascades<br>
-Receptor-Mediated Signaling (CB Receptors and Beyond)<br>
-Can increase reactive oxygen species (ROS)<br>
-Can induce ER stress, which activates the unfolded protein response.<br>
-Suppress key survival and proliferation signaling cascades such as the PI3K/Akt/mTOR pathway.<br>
-Impair angiogenesis<br>
<p><b>Cannabidiol</b> — Cannabidiol (CBD) is a non-intoxicating phytocannabinoid from <i>Cannabis sativa</i> with pleiotropic signaling effects that include ion-channel modulation, lipid-membrane stress, mitochondrial injury, oxidative stress induction, and context-dependent receptor/transcriptional effects. It is formally classified as a plant-derived cannabinoid small molecule and, clinically, as the active ingredient of the FDA-approved oral drug Epidiolex for certain seizure disorders rather than for cancer treatment. Standard abbreviations include CBD; the major acidic biosynthetic precursor is CBDA. For oncology, the evidence base is still mainly preclinical, with recurrent themes of apoptosis or autophagic death, EMT and invasion suppression, and chemo-sensitization in selected models, but translation is constrained by formulation-dependent exposure, extensive first-pass metabolism, and clinically important drug-interaction and hepatic-safety considerations.</p>
<p><b>Primary mechanisms (ranked):</b></p>
<ol>
<li>Mitochondrial stress with ROS increase, membrane depolarization, and intrinsic cell-death signaling.</li>
<li>TRP-channel mediated Ca²⁺ dysregulation, especially TRPV2 or TRPV4-linked stress responses in glioma models.</li>
<li>ER stress and integrated stress-response signaling, including ATF4–DDIT3/CHOP-associated death programs.</li>
<li>PI3K/Akt/mTOR survival-axis suppression with secondary effects on proliferation, autophagy, and metabolic fitness.</li>
<li>Anti-migratory and anti-metastatic signaling, including EMT reversal and Wnt/β-catenin suppression in colorectal cancer models.</li>
<li>PPARγ-associated pro-death and anti-proliferative signaling in some tumor contexts.</li>
<li>Ceramide-linked stress signaling in pancreatic cancer models.</li>
<li>Chemosensitization through enhanced drug uptake or stress amplification in selected models, especially glioma.</li>
</ol>
<p><b>Bioavailability / PK relevance:</b> CBD is highly lipophilic, has low and formulation-sensitive oral bioavailability, and undergoes extensive hepatic and gut metabolism primarily via CYP2C19, CYP3A4, and UGT pathways. Food markedly changes exposure; high-fat meals can increase systemic exposure several-fold. The approved prescription formulation has a long terminal half-life after repeated dosing, but oncology studies and commercial products are heterogeneous in formulation, route, and reliability of exposure.</p>
<p><b>In-vitro vs systemic exposure relevance:</b> This is a major translation constraint. Many anticancer in-vitro studies use low-to-moderate or higher micromolar concentrations that may not be reproducibly achievable in tumors with standard oral dosing, especially with non-pharmaceutical products. Some local-delivery, inhaled, or nanoformulation approaches may improve relevance, but for most cancer contexts the mechanistic literature still outpaces clinically validated exposure-response data.</p>
<p><b>Clinical evidence status:</b> Preclinical evidence is substantial. Human cancer evidence is limited to small early-phase studies, supportive-care trials, and ongoing exploratory cancer trials; there is no established cancer-directed indication. Current oncology guidance supports discussing cannabis or cannabinoids for selected supportive-care scenarios but recommends against using them as anticancer therapy outside clinical trials.</p>
-Liver injury is one of the main labeled toxicities: ALT elevations above 3× ULN occurred in 12% to 13% of treated patients in controlled studies<br>
<h3>Mechanistic ranking</h3>
<table border="1" cellpadding="4" cellspacing="0">
<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>
<tr>
<td>1</td>
<td>Mitochondrial ROS and membrane injury</td>
<td>ROS ↑; ΔΨm ↓; cytochrome c release ↑; caspase signaling ↑</td>
<td>↔ or less sensitive in some models</td>
<td>R/G</td>
<td>Apoptosis or lethal stress</td>
<td>Most central cross-tumor mechanism; often upstream of apoptosis and stress-pathway collapse.</td>
</tr>
<tr>
<td>2</td>
<td>TRPV2 or TRPV4 Ca²⁺ influx</td>
<td>Ca²⁺ influx ↑; stress signaling ↑; drug uptake ↑</td>
<td>Limited effect reported in some astrocyte comparisons</td>
<td>P/R</td>
<td>Autophagy, apoptosis, chemosensitization</td>
<td>Especially relevant in glioma literature; supports both direct cytotoxicity and adjunct sensitization.</td>
</tr>
<tr>
<td>3</td>
<td>ER stress and integrated stress response</td>
<td>ATF4 ↑; DDIT3 CHOP ↑; UPR stress ↑</td>
<td>Usually weaker or not well defined</td>
<td>R/G</td>
<td>Death-program engagement</td>
<td>Frequently coupled to Ca²⁺ dysregulation, ceramide changes, and mitochondrial dysfunction.</td>
</tr>
<tr>
<td>4</td>
<td>PI3K Akt mTOR survival signaling</td>
<td>PI3K/Akt/mTOR ↓</td>
<td>↔ (context-dependent)</td>
<td>R/G</td>
<td>Reduced survival and growth</td>
<td>A common convergence node rather than always the initiating lesion.</td>
</tr>
<tr>
<td>5</td>
<td>Apoptosis execution program</td>
<td>Apoptosis ↑; caspase 3 8 9 ↑; PARP cleavage ↑</td>
<td>↔ or less pronounced in selected comparisons</td>
<td>G</td>
<td>Tumor cell loss</td>
<td>Robust downstream phenotype across many cell systems.</td>
</tr>
<tr>
<td>6</td>
<td>Autophagy and mitophagy</td>
<td>Autophagy ↑; mitophagy arrest or lethal autophagy ↑</td>
<td>Unclear selectivity</td>
<td>R/G</td>
<td>Stress adaptation failure or non-apoptotic death</td>
<td>Can be cytotoxic or partially adaptive depending on model; important in glioma work.</td>
</tr>
<tr>
<td>7</td>
<td>EMT and Wnt β-catenin axis</td>
<td>Wnt/β-catenin ↓; Snail ↓; vimentin ↓; E-cadherin ↑; metastasis programs ↓</td>
<td>Not established as a core normal-cell effect</td>
<td>G</td>
<td>Migration and invasion suppression</td>
<td>Strong recent relevance in colorectal cancer models and consistent with the Nestronics entry.</td>
</tr>
<tr>
<td>8</td>
<td>PPARγ signaling</td>
<td>PPARγ ↑</td>
<td>↔ (context-dependent)</td>
<td>R/G</td>
<td>Pro-apoptotic transcriptional shift</td>
<td>Mechanistically meaningful but not universal across tumor types.</td>
</tr>
<tr>
<td>9</td>
<td>Mitochondrial ROS increase secondary redox axis</td>
<td>ROS ↑</td>
<td>Potential antioxidant or mixed effects in non-cancer settings</td>
<td>P/R</td>
<td>Stress amplification</td>
<td>Include as a secondary redox axis rather than as the sole mechanism because CBD redox effects are context-dependent.</td>
</tr>
<tr>
<td>10</td>
<td>HIF-1α and angiogenesis signaling</td>
<td>HIF-1α ↓; pro-angiogenic tone ↓</td>
<td>Not clearly established clinically</td>
<td>G</td>
<td>Vascular support restraint</td>
<td>Present in preclinical literature and also reflected on the Nestronics page, but not a top translation driver.</td>
</tr>
<tr>
<td>11</td>
<td>Ceramide stress signaling</td>
<td>CerS1 ↑; ceramide stress ↑</td>
<td>Unknown</td>
<td>R/G</td>
<td>ER stress linked cytotoxicity</td>
<td>Currently most notable in pancreatic cancer work; may be subtype-specific.</td>
</tr>
<tr>
<td>12</td>
<td>Glycolysis and lipogenesis</td>
<td>Lipogenesis ↓; metabolic fitness ↓</td>
<td>Systemic lipid effects also occur outside oncology</td>
<td>G</td>
<td>Metabolic disadvantage</td>
<td>Mechanistically relevant but less mature as a core anticancer axis than stress-death signaling.</td>
</tr>
<tr>
<td>13</td>
<td>Chemosensitization</td>
<td>Sensitivity to cytotoxics ↑</td>
<td>Potential therapeutic window depends on regimen</td>
<td>G</td>
<td>Adjunct leverage</td>
<td>Most persuasive in glioma and some combination-model systems; clinically still exploratory.</td>
</tr>
<tr>
<td>14</td>
<td>Clinical Translation Constraint</td>
<td>Micromolar in-vitro activity often exceeds routine systemic tumor exposure</td>
<td>Normal-tissue PK and DDI burden remain clinically relevant</td>
<td>G</td>
<td>Limits standalone translation</td>
<td>Poor and meal-sensitive oral bioavailability, product heterogeneity, hepatic injury risk, sedation, and CYP UGT interactions are major constraints.</td>
</tr>
</table>
<p>P: 0–30 min<br>R: 30 min–3 hr<br>G: >3 hr</p>