Description: <b>Hydroxycinnamic acid</b> compounds (p-coumaric, caffeic acid (CA), ferulic acid) occur most frequently as simple esters with hydroxy carboxylic acids or glucose, while the hydroxybenzoic acid compounds (p-hydroxybenzoic, gallic acid, ellagic acid) are present mainly in the form of glucosides. https://www.sciencedirect.com/topics/chemistry/hydroxycinnamic-acid<br>
Hydroxycinnamic acids (HCAs) are plant-derived phenolic acids (including caffeic, ferulic, p-coumaric, and sinapic acids) with documented antioxidant, anti-inflammatory (NF-κB↓), and context-dependent anticancer effects in cellular and preclinical models. Mechanistic themes include activation of the Nrf2/ARE antioxidant response, suppression of pro-inflammatory and survival pathways (such as NF-κB and PI3K/AKT), modulation of MAPK signaling, and downstream effects on cell-cycle, apoptosis, invasion, and angiogenesis. Oral exposure is influenced by rapid metabolism (phase II conjugates) and food matrix effects, which affects systemic bioavailability and translational relevance. Biological effects vary by specific hydroxycinnamic derivative and its conjugated/esterified form. (Caffeic acid ≠ ferulic acid ≠ sinapic acid)<br>
<br>
-Ferulic acid and p‐coumaric acid are naturally occurring hydroxycinnamic acids found in many plant-based foods (such as whole grains, fruits, and vegetables)<br>
<br>
CA showed pro-oxidant potential due to its ability to interact with metals like copper, inducing lipid peroxidation and causing DNA damage within tumor cells through either oxidation or covalent adduct formation.<br>
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Summary:<br>
-HCAs are classically antioxidant<br>
-Such as caffeic acid, ferulic acid, and sinapic acid (SA)<br>
-May increase sensitivity to
<a href="https://nestronics.ca/dbx/tbResList.php?qv=95&tsv=1106&wNotes=0">chemotherapy</a><br>
-Bioavailability is problem. Formulation strategies (e.g., liposomal or encapsulated forms) are investigated to improve systemic exposure.<br>
-Propolis has caffeic acid (Caffeic acid (0.639–4.172 mg/g propolis)<br>
-SA at higher concentrations may acts as a potent pro-oxidant agent<br>
-SA may act in collaboration with other chemotherapeutic agents to improve treatment sensitivity.
-Co-administration of caffeic acid or CAPE with other anti-tumor compounds (e.g., gallic acid) has shown additive or synergistic effects in selected models<br>
-Combination of caffeic acid and endogenous copper ions can result in oxidative damage<br>
-Ferulic Acid (abundant in whole grains,popcorn): upregulate apoptotic protein and downregulate anti-apoptotic protein.upregulating (BAX), (p53), (CYCS) and downregulating (Bcl-2),<br>
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<h3>Major Hydroxycinnamic Acids and Their Main Mechanisms</h3>
<table>
<thead>
<tr>
<th>Hydroxycinnamic Acid</th>
<th>Abbreviation</th>
<th>Major Sources</th>
<th>Main Mechanisms of Action</th>
<th>Cancer-Relevant Emphasis</th>
<th>Notes</th>
</tr>
</thead>
<tbody>
<tr>
<td><a href="https://nestronics.ca/dbx/tbResList.php?qv=51">Caffeic acid</a></td>
<td>CA</td>
<td>Coffee, fruits, vegetables, herbs; also released from chlorogenic acids</td>
<td>
ROS modulation; NF-κB suppression; apoptosis induction; mitochondrial dysfunction in cancer cells; inhibition of migration and invasion; antioxidant activity in normal tissue
</td>
<td>
ROS ↑ or ↓ (context-dependent); BAX ↑; BCL-2 ↓; caspases ↑; NF-κB ↓; MMPs ↓
</td>
<td>
One of the better-studied HCAs. Can act as an antioxidant at physiological exposure but become pro-oxidant under selected high-concentration or metal-dependent conditions.
</td>
</tr>
<tr>
<td><a href="https://nestronics.ca/dbx/tbResList.php?qv=77">Ferulic acid</a></td>
<td>FA</td>
<td>Whole grains, bran, rice, wheat, oats, fruits, vegetables</td>
<td>
Cell-cycle arrest; mitochondrial apoptosis; PI3K/AKT/mTOR suppression; NF-κB inhibition; NRF2 activation in normal tissue; inhibition of EMT, migration and invasion
</td>
<td>
p53 ↑; p21 ↑; cyclins/CDKs ↓; BAX ↑; BCL-2 ↓; PI3K/AKT/mTOR ↓; MMP-2/9 ↓
</td>
<td>
Probably the most broadly characterized HCA for anticancer signaling. Many direct cytotoxic effects occur at concentrations much higher than typical dietary plasma exposure.
</td>
</tr>
<tr>
<td><a href="https://nestronics.ca/dbx/tbResList.php?qv=453">p-Coumaric acid</a></td>
<td>p-CA</td>
<td>Cereals, tomatoes, peanuts, fruits, vegetables, wine</td>
<td>
Antioxidant and redox modulation; apoptosis; cell-cycle suppression; inflammatory signaling inhibition; glycolytic suppression in selected models
</td>
<td>
ROS modulation; apoptosis ↑; NF-κB ↓; PKM2 ↓ and glycolysis ↓ in selected models
</td>
<td>
Frequently studied in combination with ferulic acid. Metabolic effects such as PKM2 suppression should not be assumed to be universal.
</td>
</tr>
<tr>
<td><a href="https://nestronics.ca/dbx/tbResList.php?qv=454">Sinapic acid</a></td>
<td>SA</td>
<td>Brassica vegetables, mustard, rapeseed, cereals</td>
<td>
Antioxidant activity; ROS-mediated apoptosis at higher concentrations; inflammatory pathway suppression; mitochondrial apoptosis; modulation of MAPK signaling
</td>
<td>
ROS ↑ (high concentration) or ↓; mitochondrial apoptosis ↑; NF-κB ↓; MAPK modulation
</td>
<td>
Less extensively characterized than caffeic or ferulic acid. Strong antioxidant effects predominate in many non-cancer models.
</td>
</tr>
<tr>
<td><a href="https://nestronics.ca/dbx/tbResList.php?qv=59">Chlorogenic acid</a></td>
<td>CGA</td>
<td>Coffee, apples, pears, berries, potatoes</td>
<td>
Antioxidant and NRF2-associated cytoprotection; inhibition of inflammatory signaling; modulation of AMPK, PI3K/AKT and apoptosis pathways; glucose-metabolism regulation
</td>
<td>
NF-κB ↓; PI3K/AKT ↓ (model-dependent); apoptosis ↑; ROS modulation; AMPK ↑
</td>
<td>
An ester of caffeic acid and quinic acid rather than a simple free HCA. Often treated separately because its absorption and metabolism differ substantially from caffeic acid.
</td>
</tr>
<tr>
<td><a href="https://nestronics.ca/dbx/tbResList.php?qv=395">Caffeic acid phenethyl ester</a> </td>
<td>CAPE</td>
<td>Propolis</td>
<td>
Potent NF-κB inhibition; ROS-mediated cancer-cell killing; mitochondrial apoptosis; suppression of proliferation, angiogenesis and invasion
</td>
<td>
NF-κB ↓; ROS ↑; BAX ↑; BCL-2 ↓; VEGF ↓; MMPs ↓
</td>
<td>
A caffeic-acid derivative rather than a simple dietary HCA. Its pharmacology is sufficiently distinct that it is usually best treated as a separate compound.
</td>
</tr>
<tr>
<td><a href="https://nestronics.ca/dbx/tbResList.php?qv=142">Rosmarinic acid</a></td>
<td>RA</td>
<td>Rosemary, basil, lemon balm, sage and other Lamiaceae herbs</td>
<td>
Antioxidant and NRF2 activation; NF-κB inhibition; apoptosis; suppression of PI3K/AKT and EMT; anti-inflammatory signaling
</td>
<td>
ROS ↓ or ↑ (context-dependent); NRF2 ↑; NF-κB ↓; PI3K/AKT ↓; EMT ↓; apoptosis ↑
</td>
<td>
An ester containing caffeic-acid-related structures. Often considered a hydroxycinnamic-acid derivative rather than a simple HCA.
</td>
</tr>
<tr>
<td>Isoferulic acid</td>
<td>IFA</td>
<td>Cimicifuga species and selected medicinal plants</td>
<td>
Antioxidant activity; inflammatory signaling suppression; glucose-metabolism modulation; apoptosis and growth inhibition in limited cancer models
</td>
<td>
NF-κB ↓; ROS ↓; apoptosis ↑ (model-dependent)
</td>
<td>
Structural isomer of ferulic acid with substantially less cancer-specific evidence.
</td>
</tr>
<tr>
<td>o-Coumaric acid</td>
<td>o-CA</td>
<td>Plants, cereals and some fruits</td>
<td>
Antioxidant and antimicrobial effects; limited evidence for apoptosis and proliferation suppression
</td>
<td>
ROS modulation; proliferation ↓ (limited evidence)
</td>
<td>
Much less studied for cancer than p-coumaric acid.
</td>
</tr>
<tr>
<td>m-Coumaric acid</td>
<td>m-CA</td>
<td>Minor constituent of various plants and foods</td>
<td>
Antioxidant and redox modulation; limited anti-inflammatory and antiproliferative activity
</td>
<td>
ROS modulation; inflammatory signaling ↓ (limited evidence)
</td>
<td>
Cancer evidence is sparse compared with the para isomer.
</td>
</tr>
</tbody>
</table>
<p><b>Practical grouping:</b> For a class-level Hydroxycinnamic Acid entry, the four core free HCAs are <b>caffeic acid, ferulic acid, p-coumaric acid, and sinapic acid</b>. Chlorogenic acid, rosmarinic acid, and CAPE are chemically related HCA derivatives but have sufficiently distinct pharmacokinetics and biological activity that they are often better maintained as separate database products.</p>
<p><b>Hydroxycinnamic acids</b> — HCAs are a family of plant-derived phenolic acids characterized by a C6-C3 cinnamic-acid backbone bearing one or more hydroxyl/methoxy substituents. Major dietary HCAs include caffeic acid, ferulic acid, p-coumaric acid, and sinapic acid; chlorogenic acids and related esters are important dietary conjugates. HCAs are classified as non-flavonoid polyphenolic phenolic acids and occur widely in coffee, cereals, fruits, vegetables, herbs, and plant-derived foods. They are not a single pharmacologically uniform agent: caffeic acid, ferulic acid, p-coumaric acid, and sinapic acid can differ substantially in potency, redox behavior, metabolism, and molecular targets. Anticancer activity remains predominantly preclinical and should generally be attributed to the specific HCA rather than generalized to the entire class.</p>
<p><b>Primary mechanisms (ranked):</b></p>
<ol>
<li>Redox modulation: antioxidant activity predominates physiologically, whereas selected HCAs can become pro-oxidant in tumor models, particularly at high concentrations or in the presence of transition metals such as Cu²⁺, producing ROS and oxidative DNA damage.</li>
<li>Apoptosis and mitochondrial death signaling: selected HCAs increase BAX/BCL-2 ratio, cytochrome-c release, caspase activation, and PARP cleavage in cancer models.</li>
<li>Cell-cycle and proliferative signaling suppression: modulation of p53/p21 and suppression of cyclins/CDKs can produce G0/G1, S, or G2/M arrest depending on compound and tumor model.</li>
<li>NF-κB and inflammatory signaling suppression: HCAs frequently suppress NF-κB-associated inflammatory and prosurvival signaling, including COX-2 and inflammatory cytokine pathways.</li>
<li>PI3K/AKT/mTOR and MAPK modulation: selected HCAs inhibit prosurvival PI3K/AKT/mTOR signaling and alter ERK/JNK/p38 signaling in a strongly model-dependent manner.</li>
<li>Migration, EMT and extracellular-matrix remodeling: reduced MMP-2/MMP-9, EMT signaling, migration and invasion are reported for several HCAs.</li>
<li>Metabolic suppression: ferulic acid plus p-coumaric acid has been reported to suppress PKM2-associated aerobic glycolysis; this is mechanistically interesting but should not yet be generalized to all HCAs.</li>
<li>NRF2/ARE antioxidant response (secondary): activation of NRF2, HO-1 and endogenous antioxidant systems is prominent in normal/stressed tissues and contributes to cytoprotection; in established cancer, NRF2 activation could theoretically be tumor-protective in some contexts.</li>
<li>Chemo- and radiosensitization (context-dependent): selected HCAs enhance chemotherapy- or radiation-induced tumor-cell killing experimentally, but evidence is compound- and model-specific rather than a demonstrated class-wide clinical effect.</li>
</ol>
<p><b>Bioavailability / PK relevance:</b> HCAs are absorbed from the gastrointestinal tract, but the parent aglycones undergo substantial intestinal, hepatic and microbiome metabolism, particularly glucuronidation, sulfation, methylation and hydrogenation. Circulating exposure therefore consists substantially of conjugated and microbial metabolites rather than unchanged parent compound. Food matrix, esterification and site of intestinal release materially alter exposure. Pharmacokinetic reviews indicate that systemic parent-HCA concentrations after dietary intake are generally in the submicromolar-to-low-micromolar range, with one recent systematic assessment reporting maximal blood concentrations around 0.4 µM for cinnamic-acid derivatives such as caffeic/ferulic acid in the datasets examined. Formulation approaches including nanoparticles and encapsulation are being investigated to increase exposure.</p>
<p><b>In-vitro vs systemic exposure relevance:</b> Many reported direct anticancer effects use tens to hundreds of micromolar HCA concentrations. For example, ferulic acid produced IC50 values of approximately 300 µM in PC-3 and 500 µM in LNCaP prostate cancer cells. These concentrations greatly exceed typical circulating concentrations attainable from ordinary dietary exposure. Consequently, direct tumor-cell cytotoxicity demonstrated at high in-vitro concentrations should not be interpreted as evidence that dietary HCAs achieve equivalent systemic anticancer exposure. Metabolites, local gastrointestinal exposure, chronic signaling effects and specialized formulations may have different pharmacological relevance.</p>
<p><b>Clinical evidence status:</b> <b>Preclinical for cancer treatment.</b> There is substantial cell-culture evidence and some animal-tumor evidence for individual HCAs, especially ferulic and caffeic acids, but no established HCA-class anticancer therapy and no convincing randomized human evidence demonstrating treatment of established cancer with isolated HCAs. Human studies more commonly concern dietary exposure, cardiovascular/metabolic effects, pharmacokinetics, skin photoprotection or complex HCA-containing foods/extracts. HCAs should therefore be classified as experimental/preclinical anticancer agents rather than clinical adjuncts.</p>
<h3>Hydroxycinnamic Acid Cancer Mechanisms</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>Redox balance and ROS</td>
<td>ROS ↑ or ↓ (dose-dependent) (context-dependent)</td>
<td>ROS ↓; oxidative injury ↓</td>
<td>P, R</td>
<td>Redox stress modulation</td>
<td>HCAs are generally antioxidants at physiological exposure but caffeic, sinapic and related HCAs can become pro-oxidant under selected conditions. Cu²⁺-dependent oxidative DNA damage is a documented mechanism and should not be generalized to normal dietary exposure.</td>
</tr>
<tr>
<td>2</td>
<td>Mitochondrial apoptosis</td>
<td>BAX ↑; BCL-2 ↓; cytochrome-c ↑; caspases ↑; apoptosis ↑</td>
<td>↔ (model-dependent)</td>
<td>R, G</td>
<td>Intrinsic and extrinsic apoptosis</td>
<td>Strongly represented in ferulic, caffeic and sinapic acid tumor-cell studies, typically at pharmacological in-vitro concentrations.</td>
</tr>
<tr>
<td>3</td>
<td>Cell-cycle checkpoints</td>
<td>p53 ↑; p21 ↑; cyclins ↓; CDK2/4/6 ↓; cell-cycle arrest ↑</td>
<td>↔</td>
<td>G</td>
<td>Cytostasis</td>
<td>Ferulic acid has experimentally increased TP53, CDKN1A and CDKN1B while suppressing several cyclins and CDKs; exact arrest phase varies with cell type.</td>
</tr>
<tr>
<td>4</td>
<td>NF-κB inflammatory and survival signaling</td>
<td>NF-κB ↓; COX-2 ↓; inflammatory signaling ↓</td>
<td>NF-κB ↓ (stress-dependent); inflammation ↓</td>
<td>R, G</td>
<td>Anti-inflammatory and prosurvival suppression</td>
<td>One of the more reproducible HCA-family signaling themes, although strength varies among individual derivatives.</td>
</tr>
<tr>
<td>5</td>
<td>PI3K AKT mTOR survival axis</td>
<td>PI3K ↓; AKT ↓; mTOR ↓ (model-dependent)</td>
<td>↔ or mTOR ↓ (context-dependent)</td>
<td>R, G</td>
<td>Growth and survival suppression</td>
<td>Reported particularly for ferulic and other individual HCAs; not sufficiently uniform to assign identical modulation to every member of the class.</td>
</tr>
<tr>
<td>6</td>
<td>Migration EMT and matrix remodeling</td>
<td>MMP-2 ↓; MMP-9 ↓; EMT ↓; migration ↓; invasion ↓</td>
<td>↔</td>
<td>G</td>
<td>Anti-invasive phenotype</td>
<td>Observed in breast, prostate, thyroid, pancreatic and other experimental cancer systems with selected HCAs.</td>
</tr>
<tr>
<td>7</td>
<td>MAPK signaling</td>
<td>ERK JNK p38 ↔ (context-dependent)</td>
<td>ERK JNK p38 ↔ (context-dependent)</td>
<td>P, R, G</td>
<td>Stress and proliferation signaling</td>
<td>Direction is highly dependent on derivative, concentration, duration and cell type; a fixed class-wide arrow is inappropriate.</td>
</tr>
<tr>
<td>8</td>
<td>PKM2 and aerobic glycolysis</td>
<td>PKM2 ↓; glycolysis ↓</td>
<td>↔</td>
<td>R, G</td>
<td>Metabolic growth restriction</td>
<td>Demonstrated particularly for combined ferulic acid plus p-coumaric acid through an lncRNA/PKM2-associated mechanism. This is not established as a universal HCA effect.</td>
</tr>
<tr>
<td>9</td>
<td>Angiogenesis signaling</td>
<td>VEGF ↓; angiogenesis ↓ (model-dependent)</td>
<td>↔</td>
<td>G</td>
<td>Anti-angiogenic activity</td>
<td>Preclinical evidence exists for selected HCAs and derivatives but is less central than apoptosis, redox and proliferation mechanisms.</td>
</tr>
<tr>
<td>10</td>
<td>NRF2 ARE antioxidant response</td>
<td>NRF2 ↑ or ↔ (context-dependent)</td>
<td>NRF2 ↑; HO-1 ↑; GSH systems ↑</td>
<td>R, G</td>
<td>Secondary antioxidant adaptation</td>
<td>Generally cytoprotective in normal tissues. NRF2 activation is not necessarily desirable in established tumors because persistent NRF2 signaling can support tumor stress resistance.</td>
</tr>
<tr>
<td>11</td>
<td>Chemosensitization</td>
<td>Drug sensitivity ↑ (model-dependent)</td>
<td>Normal-tissue toxicity ↓ in some models</td>
<td>G</td>
<td>Combination-treatment modulation</td>
<td>Reported with selected HCAs and specific anticancer agents. Evidence remains preclinical and cannot be generalized to chemotherapy as a whole.</td>
</tr>
<tr>
<td>12</td>
<td>Radiosensitization</td>
<td>Radiation sensitivity ↑ (model-dependent)</td>
<td>Radioprotection reported in other contexts</td>
<td>P, R, G</td>
<td>Radiation-response modulation</td>
<td>Ferulic acid has sensitized cervical cancer cells experimentally through enhanced oxidative damage, while antioxidant properties can be radioprotective in normal tissues.</td>
</tr>
<tr>
<td>13</td>
<td>Clinical Translation Constraint</td>
<td>Parent-compound exposure ↓; extensive conjugation ↑</td>
<td>Dietary exposure generally well tolerated</td>
<td>R, G</td>
<td>Bioavailability and dose limitation</td>
<td>Many anticancer experiments use approximately 10–500 µM concentrations whereas typical circulating dietary exposure is far lower and substantially metabolized. Human cancer efficacy has not been established.</td>
</tr>
</tbody>
</table>
<p><b>TSF:</b> P: 0–30 min R: 30 min–3 hr G: >3 hr</p>
<br><br>
<p><b>Alzheimer’s disease:</b> Hydroxycinnamic acids have preclinical neuroprotective relevance, particularly caffeic and ferulic acids. Reported mechanisms include suppression of Aβ-associated oxidative stress and neuroinflammation, enhancement of endogenous antioxidant defenses, modulation of CREB/neurotrophic signaling, and possible effects on amyloid- and tau-associated pathology. Evidence is primarily cellular and animal-based; convincing clinical evidence that isolated HCAs prevent or treat Alzheimer’s disease is lacking. Rapid metabolism, low parent-compound systemic exposure and uncertain brain exposure remain important translational constraints.</p>
<h3>Hydroxycinnamic Acids in Alzheimer’s Disease</h3>
<table>
<thead>
<tr>
<th>Rank</th>
<th>Pathway / Axis</th>
<th>Modulation</th>
<th>Primary Effect</th>
<th>Notes / Interpretation</th>
</tr>
</thead>
<tbody>
<tr>
<td>1</td>
<td>Oxidative stress and NRF2</td>
<td>ROS ↓; NRF2 ↑; antioxidant defenses ↑</td>
<td>Neuroprotection</td>
<td>Consistent with caffeic- and ferulic-acid preclinical models; principally antioxidant/cytoprotective rather than direct disease modification established in humans.</td>
</tr>
<tr>
<td>2</td>
<td>Amyloid beta toxicity</td>
<td>Aβ toxicity ↓; associated neuronal injury ↓</td>
<td>Reduced amyloid-associated neurotoxicity</td>
<td>Caffeic acid has demonstrated protection in Aβ-induced mouse models.</td>
</tr>
<tr>
<td>3</td>
<td>Neuroinflammation</td>
<td>NF-κB-associated inflammation ↓; inflammatory mediators ↓</td>
<td>Reduced inflammatory neuronal injury</td>
<td>Supported mainly by cellular and animal studies.</td>
</tr>
<tr>
<td>4</td>
<td>CREB and neurotrophic signaling</td>
<td>CREB ↑; neuronal survival signaling ↑</td>
<td>Synaptic and neuronal support</td>
<td>Ferulic acid has been associated with CREB phosphorylation and broader neurotrophic signaling.</td>
</tr>
<tr>
<td>5</td>
<td>Tau pathology</td>
<td>Tau-associated pathology ↓ (model-dependent)</td>
<td>Potential cytoskeletal protection</td>
<td>Evidence is substantially weaker than for oxidative stress and Aβ-related mechanisms.</td>
</tr>
<tr>
<td>6</td>
<td>Clinical Translation Constraint</td>
<td>Brain exposure ↓; metabolism ↑</td>
<td>Limits therapeutic translation</td>
<td>No established HCA treatment for AD; oral bioavailability, extensive conjugation and BBB exposure remain unresolved for pharmacological use.</td>
</tr>
</tbody>
</table>