NF-κB/IκB

Nullscript is an inactive analog of Scriptaid and serves as a negative control for Scriptaid, a representative histone deacetylase (HDAC) inhibitor. Despite its inactivity as an HDAC inhibitor, Nullscript inhibits the growth of *Cryptosporidium parvum* with an IC₅₀ value of 2.1 μM.

SGC-UBD253 is a potent antagonist of the HDAC6 ubiquitin-binding domain (UBD). It is suitable for use in cancer research.

Psammaplin A, a marine-derived metabolite, is a potent inhibitor of HDAC1 (IC50: 45 nM), DNA methyltransferases (IC50: 18.6 nM), and aminopeptidase N (IC50: 18 μM). It also suppresses DNA topoisomerase and farnesyl protein transferase activities. As a PPARγ activator, Psammaplin A induces apoptosis and exhibits antitumor, anti-inflammatory, and anti-angiogenic properties. Additionally, it demonstrates antibacterial activity against Gram-positive bacteria by inhibiting DNA synthesis and DNA

CU-T12-9 is a specific and potent agonist of the Toll-like receptor 1/2 (TLR1/2) heterodimer, with an EC₅₀ of 52.9 nM in the HEK-Blue hTLR2 SEAP assay. It selectively activates TLR1/2 without affecting TLR2/6 and stimulates both innate and adaptive immune responses. CU-T12-9 signals through the NF-κB pathway, leading to elevated expression of downstream effectors such as TNF-α, IL-10, and iNOS, making it a valuable tool for immunological and inflammatory research.

SRX3177 is a potent triple inhibitor targeting CDK4/6, PI3K, and BRD4, with IC50 values of <2.5 nM for CDK4, 3.3 nM for CDK6, 79 nM for PI3Kα, 83 nM for PI3Kδ, 3.18 μM for PI3Kγ, and 33 nM and 89 nM for BRD4 BD1 and BD2, respectively. It exhibits broad cytotoxic activity against cancer cells while sparing normal epithelial cells, highlighting its potential as a targeted cancer therapeutic with reduced toxicity.

RS47 is a potent and specific inhibitor of the non-canonical NF-κB signaling pathway, acting by disrupting the binding of RelB to its target DNA with a Kd of 1.1 μM. It effectively inhibits the growth of colorectal cancer (CRC) cells and B lymphomas, making it a valuable research tool for studying and potentially targeting cancers driven by hyperactive non-canonical NF-κB signaling.

MnTBAP chloride is a superoxide dismutase (SOD) mimetic and peroxynitrite scavenger, classified as a manganic porphyrin complex with potent antioxidant properties. It exerts anti-inflammatory effects by upregulating BMPR-II expression and inhibiting NFκB signaling. MnTBAP chloride holds therapeutic potential for research into fibrotic responses in chronic kidney diseases (CKDs).

ABD56 is a bioactive compound that inhibits osteoclast formation and induces osteoclast apoptosis. Its mechanism of action involves suppression of the NFκB and ERK signaling pathways, making it a promising candidate for research in bone metabolism and osteolytic diseases.

Lobeglitazone sulfate is a novel thiazolidinedione and an orally active agonist of peroxisome proliferator-activated receptors (PPARs), with EC50 values of 137.4 nM for PPARγ and 546.3 nM for PPARα. It also acts as an inhibitor of the ERK/JNK/Smad/NF-κB signaling pathways. Lobeglitazone sulfate exhibits anti-inflammatory, anti-diabetic, anti-fibrotic, and anti-atherosclerotic activities, supporting its potential in the treatment of metabolic and inflammatory diseases.

Tauroursodeoxycholate (Tauroursodeoxycholic acid; TDUCA) dihydrate is an inhibitor of endoplasmic reticulum (ER) stress that significantly downregulates pro-apoptotic molecules, including caspase-3 and caspase-12. Additionally, it suppresses ERK signaling, contributing to its cytoprotective and anti-apoptotic effects.

Asperulosidic Acid (ASPA) is a bioactive iridoid glycoside isolated from the herb Hedyotis diffusa Willd., exhibiting anti-tumor, antioxidant, and anti-inflammatory properties. Its anti-inflammatory effects are associated with the downregulation of proinflammatory cytokines such as TNF-α and IL-6, mediated through inhibition of the NF-κB and MAPK signaling pathways.

Sulforaphene, a natural compound isolated from radish seeds, exhibits an ED₅₀ of approximately 2 × 10⁻⁴ M against velvetleaf seedlings. It promotes apoptosis and inhibits migration in cancer cells by suppressing signaling pathways including EGFR, phosphorylated ERK1/2 (p-ERK1/2), and NF-κB.

Keracyanin chloride is an orally active anthocyanin compound with potent antioxidant, anti-inflammatory, and hypoglycemic properties. It exerts its biological effects by inhibiting the NF-κB/FAK/MAPK signaling pathways, which are central to inflammation, cell adhesion, and metabolic regulation.

Penehyclidine hydrochloride (also known as Penequinine hydrochloride) is a selective anticholinergic agent that acts as an antagonist of muscarinic M1 and M3 receptors. It exerts anti-inflammatory effects by modulating immune signaling in lung tissue, notably through activation of the NF-κB pathway and inhibition of pro-inflammatory cytokine release. In preclinical studies, Penehyclidine hydrochloride has been shown to alleviate pulmonary inflammation in rat models of chronic obstructive pulmonary disease (COPD), particularly under conditions of mechanical ventilation. These properties suggest its potential utility in managing respiratory inflammatory conditions and improving outcomes in mechanically ventilated patients with COPD.

Lobeglitazone is a novel thiazolidinedione-class compound and an orally active dual agonist of peroxisome proliferator-activated receptors (PPARs), with EC₅₀ values of 137.4 nM for PPARγ and 546.3 nM for PPARα. In addition to its metabolic effects, Lobeglitazone functions as an inhibitor of multiple pro-inflammatory and pro-fibrotic signaling pathways, including ERK, JNK, Smad, and NF-κB. Lobeglitazone exhibits a broad range of pharmacological activities, including anti-inflammatory, anti-diabetic, anti-fibrotic, and anti-atherosclerotic effects. These properties make it a promising candidate for therapeutic research in metabolic syndrome, type 2 diabetes, cardiovascular disease, and fibrosis-related conditions.

Enniatin B1 is a mycotoxin produced by Fusarium species, known for its diverse bioactivities. It functions as a moderate inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT), with an IC₅₀ of 73 μM in assays using rat liver microsomes, implicating a role in lipid metabolism modulation. Enniatin B1 is capable of crossing the blood-brain barrier, suggesting potential effects on central nervous system function. It also decreases the activation of ERK1/2 (p44/p42 MAPK) and moderately inhibits TNF-α-induced NF-κB activation, indicating anti-inflammatory and cell signaling modulatory properties.

Anti-inflammatory agent 35 (compound 5a27) is an orally active curcumin analogue that exhibits potent anti-inflammatory activity. It exerts its effects by blocking mitogen-activated protein kinase (MAPK) signaling and inhibiting the nuclear translocation of the NF-κB subunit p65, thereby suppressing key inflammatory pathways. Additionally, compound 5a27 reduces neutrophil infiltration and the production of pro-inflammatory cytokines. In vivo, it significantly attenuates lipopolysaccharide (LPS)-induced acute lung injury (ALI), highlighting its potential as a therapeutic candidate for inflammatory and respiratory disorders.

Gamma-linolenic acid (γ-linolenic acid, GLA) is an orally active omega-6 unsaturated fatty acid with broad pharmacological activities. It exhibits anti-inflammatory effects by inhibiting the NF-κB signaling pathway and suppressing the phosphorylation of ERK1/2 and JNK, key mediators of inflammatory responses. GLA also induces apoptosis in cancer cells, contributing to its anticancer potential. Additionally, it possesses antioxidant properties and has been shown to improve memory function, suggesting neuroprotective benefits. These multifunctional effects position gamma-linolenic acid as a promising compound for research in inflammation, oncology, and neurological disorders.

Sappanone A is an orally active homoisoflavone isolated from Caesalpinia sappan L., exhibiting notable anti-inflammatory and antioxidant properties. It functions as an inhibitor of phosphodiesterase 4 (PDE4) and NF-κB, key regulators of inflammatory signaling. Additionally, Sappanone A activates the Nrf2 pathway, leading to increased expression of the cytoprotective enzyme heme oxygenase-1 (HO-1). Sappanone A also inhibits RANKL-induced osteoclastogenesis, suggesting potential benefits in bone metabolism disorders. With its multifaceted bioactivity, Sappanone A holds significant promise for research in inflammation-related diseases, cardiovascular conditions, and bone health.

EF24 is a synthetic curcumin analogue and a potent NF-κB inhibitor with demonstrated oral bioavailability and strong antitumor activity. It exerts its anticancer effects, particularly in oral squamous cell carcinoma (OSCC), through deactivation of the MAPK/ERK signaling pathway. EF24 is effective against various cancer cell lines, with GI₅₀ values of 0.7 μM in melanoma and 0.8 μM in breast cancer cells. In MDA-MB-231 (breast cancer) and DU-145 (prostate cancer) cells, EF24 induces cell cycle arrest and apoptosis, accompanied by increased activation of caspase-3 and caspase-9. It also reduces the phosphorylation of MEK1 and ERK, further contributing to its pro-apoptotic and anti-proliferative effects. These properties make EF24 a promising compound for cancer therapy research.

Inflachromene is a microglial inhibitor that exerts anti-inflammatory effects by directly binding to high mobility group box proteins HMGB1 and HMGB2. Through this interaction, it effectively downregulates the proinflammatory activities of HMGB proteins, leading to reduced microglial activation and neuronal damage. Inflachromene holds promise as a therapeutic candidate for the treatment of neuroinflammatory disorders, including neurodegenerative diseases and central nervous system injuries.

Gypenoside L is a bioactive saponin isolated from *Gynostemma pentaphyllum*, known for its diverse pharmacological properties. It induces cellular senescence by increasing senescence-associated β-galactosidase (SA-β-gal) activity and promoting the secretion of senescence-associated secretory phenotype (SASP) cytokines. Mechanistically, Gypenoside L activates the p38 and ERK MAPK pathways as well as the NF-κB signaling pathway to trigger senescence. In addition to its pro-senescent effects, Gypenoside L exhibits notable anti-tumor and anti-inflammatory activities, making it a promising compound for research in cancer biology and inflammation-related diseases.

Elevenostat (JB3-22) is a selective histone deacetylase 11 (HDAC11) inhibitor with an IC₅₀ of 0.235 µM. It exhibits antitumor activity by inducing apoptosis in multiple myeloma cells and shows potential as a therapeutic agent in hematologic malignancies. Additionally, Elevenostat has been shown to inhibit the maturation of mouse oocytes, suggesting a role for HDAC11 in reproductive biology and offering a tool for studying epigenetic regulation in oocyte development.

Bufexamac is a nonsteroidal anti-inflammatory drug (NSAID) that functions as a dual inhibitor of class IIb histone deacetylases—HDAC6 and HDAC10—as well as leukotriene A4 hydrolase (LTA4H). It exhibits binding affinities (K\_d) of 0.53 µM for HDAC6 and 0.22 µM for HDAC10. Through its dual inhibitory activity, Bufexamac combines epigenetic modulation with anti-inflammatory effects, making it a valuable compound for research in inflammation, immune regulation, and HDAC-related pathologies.

TYA-018 is an orally active, potent, and highly selective inhibitor of histone deacetylase 6 (HDAC6). In preclinical studies, TYA-018 demonstrates cardioprotective effects by preserving heart function in mice. Additionally, it enhances systemic energetics by upregulating the expression of genes involved in fatty acid metabolism, protein turnover, and oxidative phosphorylation, highlighting its potential in both cardiovascular and metabolic disease research.

CYD19 is a potent dual-target inhibitor that simultaneously disrupts Snail and HDAC1 activity. It exhibits an IC₅₀ of 0.405 μM against HDAC1 and binds Snail with a K\_d of 0.18 μM. In HCT-116 colorectal cancer cells, CYD19 increases histone H4 acetylation and downregulates Snail protein expression, leading to the induction of apoptosis. This dual mechanism positions CYD19 as a promising therapeutic candidate for targeting epithelial–mesenchymal transition (EMT) and epigenetic dysregulation in cancer.

TNG260 is a selective and orally bioavailable inhibitor of histone deacetylase 1 (HDAC1) and the CoREST transcriptional corepressor complex. It exhibits approximately 10-fold selectivity for HDAC1 over HDAC3 and 500-fold selectivity for the CoREST complex compared to other HDAC-containing complexes such as NuRD and Sin3. TNG260 modulates the tumor immune microenvironment by reducing immunosuppressive neutrophil infiltration, enhancing effector T cell recruitment, and reversing anti-PD-1 resistance associated with STK11 mutations through inhibition of the CoREST–HDAC1 axis. In preclinical models, TNG260 induces durable tumor regression when combined with α-PD-1 therapy in MC38 tumor-bearing mice harboring STK11 mutations, while demonstrating reduced hematologic toxicity compared to non-selective HDAC inhibitors.

Rhamnetin is a naturally occurring flavonoid and quercetin derivative found in *Coriandrum sativum*. It functions as an inhibitor of secretory phospholipase A₂ and histone deacetylase 2 (HDAC2), contributing to its broad pharmacological profile. Rhamnetin exhibits notable antitumor, antioxidant, and anti-inflammatory activities, making it a promising compound for research in cancer, oxidative stress-related conditions, and inflammatory diseases.

DKFZ-748 is a selective histone deacetylase 10 (HDAC10) inhibitor with a pIC₅₀ of 7.66, corresponding to an IC₅₀ of approximately 22 nM. It exhibits antitumor activity, making it a valuable tool for studying HDAC10-mediated biological processes and a promising candidate for the development of targeted cancer therapies.

KA2507 is a potent, orally active, and highly selective histone deacetylase 6 (HDAC6) inhibitor with an IC₅₀ of 2.5 nM. It exhibits strong antitumor activity and immunomodulatory effects in preclinical models, making it a promising candidate for cancer therapy, particularly in tumors where HDAC6 plays a key role in tumor progression and immune evasion.

KR-39038 is a potent and orally bioavailable inhibitor of G protein-coupled receptor kinase 5 (GRK5), with an IC₅₀ of 0.02 μM. It effectively suppresses angiotensin II–induced cellular hypertrophy by inhibiting the HDAC5 signaling pathway in neonatal cardiomyocytes. KR-39038 exhibits strong anti-hypertrophic activity and improves cardiac function in preclinical models, making it a promising candidate for research in heart failure and related cardiovascular diseases.

T-518 is an orally active, selective histone deacetylase 6 (HDAC6) inhibitor with an IC₅₀ of 36 nM for human HDAC6. It is capable of crossing the blood–brain barrier, making it suitable for central nervous system applications. T-518 is particularly useful in tauopathy research, where HDAC6 inhibition may modulate tau pathology and neurodegenerative processes.

9-Hydroxyoctadecanoic acid (9-HSA) is a naturally derived inhibitor of histone deacetylase 1 (HDAC1), inhibiting approximately 66.4% of HDAC1 enzymatic activity at a concentration of 5 μM. It exhibits notable anticancer activity, likely through epigenetic modulation of gene expression, making it a promising compound for cancer research and therapeutic development targeting HDAC1-regulated pathways.

SE-7552 is an orally active, highly selective histone deacetylase 6 (HDAC6) inhibitor, based on a 2-(difluoromethyl)-1,3,4-oxadiazole (DFMO) scaffold, with an IC₅₀ of 33 nM. As a non-hydroxamate HDAC6 inhibitor, SE-7552 demonstrates exceptional isoform selectivity, showing over 850-fold preference for HDAC6 compared to other HDAC isozymes. In preclinical studies, SE-7552 effectively inhibits multiple myeloma tumor growth in vivo and also exhibits anti-obesity effects in diet-induced obese mouse models, highlighting its therapeutic potential in both oncology and metabolic disease research.

Gnetol is a bioactive phenolic compound isolated from the root of *Gnetum montanum* with diverse pharmacological properties. It potently inhibits cyclooxygenase-1 (COX-1) with an IC₅₀ of 0.78 μM and exhibits histone deacetylase (HDAC) inhibitory activity. Gnetol is also a strong tyrosinase inhibitor, with an IC₅₀ of 4.5 μM against murine tyrosinase, leading to suppression of melanin biosynthesis. In addition to its antioxidant, antiproliferative, anticancer, and hepatoprotective effects, Gnetol modulates metabolic enzymes in a concentration-dependent manner, including α-amylase, α-glucosidase, and adipogenesis pathways, making it a promising candidate for research in oncology, dermatology, and metabolic disorders.

Marein is a natural compound with multifaceted pharmacological properties, including HDAC inhibition with an IC₅₀ of 100 μM. It exerts neuroprotective effects by preserving mitochondrial function and activating the AMPK signaling pathway. In HepG2 cells, Marein improves high glucose–induced insulin resistance by enhancing glucose uptake via the CaMKK/AMPK/GLUT1 pathway, promoting glycogen synthesis through the IRS/Akt/GSK-3β pathway, and suppressing gluconeogenesis via the Akt/FoxO1 axis. Additionally, Marein possesses antioxidative, antihypertensive, antihyperlipidemic, and antidiabetic properties, making it a promising candidate for metabolic and neurodegenerative disease research.

Crebinostat is a potent, broad-spectrum histone deacetylase (HDAC) inhibitor with IC₅₀ values of 0.7 nM (HDAC1), 1.0 nM (HDAC2), 2.0 nM (HDAC3), and 9.3 nM (HDAC6). It effectively induces acetylation of histone H3 and H4, and enhances the expression of Egr1, a cAMP response element-binding protein (CREB) target gene. In cultured neurons, Crebinostat increases the density of synapsin-1 puncta along dendrites, indicating enhanced synaptic connectivity. By modulating chromatin-mediated neuroplasticity, Crebinostat has been shown to improve memory performance in mice, supporting its potential for neuropsychiatric and cognitive disorder research.

Bakkenolide A is a natural sesquiterpene lactone isolated from *Petasites tricholobus*. It exhibits anti-leukemic activity by modulating epigenetic and signaling pathways, specifically through inhibition of histone deacetylase 3 (HDAC3) and regulation of the PI3K/Akt signaling cascade. These combined effects contribute to its potential as a therapeutic agent in leukemia research.

NCC-149 is a selective inhibitor of histone deacetylase 8 (HDAC8), making it a valuable tool for studying HDAC8-specific functions. It has shown utility in promoting neural differentiation, and is particularly useful in research focused on neurodevelopmental processes and potential therapeutic strategies for neurological disorders involving epigenetic dysregulation.

CM-1758 is a histone deacetylase (HDAC) inhibitor with demonstrated antitumor activity in vivo. In acute myeloid leukemia (AML) cells, CM-1758 induces the acetylation of non-histone proteins, suggesting a broader epigenetic and post-translational regulatory effect beyond chromatin remodeling. Its dual impact on tumor growth and protein acetylation supports its potential as a therapeutic agent in hematologic malignancies.

MPT0G211 is a highly potent, orally bioavailable, and selective histone deacetylase 6 (HDAC6) inhibitor, with an IC₅₀ of 0.291 nM and over 1000-fold selectivity against other HDAC isoforms. It efficiently crosses the blood–brain barrier and demonstrates neuroprotective effects by reducing tau phosphorylation and improving cognitive function in Alzheimer's disease models. Additionally, MPT0G211 exhibits anti-metastatic and anticancer activities, making it a promising therapeutic candidate for both neurodegenerative disorders and oncology research.

MPT0B390 is a potent arylsulfonamide-based histone deacetylase (HDAC) inhibitor that also functions as an inducer of tissue inhibitor of metalloproteinases 3 (TIMP3). It exhibits strong antitumor properties, including inhibition of tumor growth, metastasis, and angiogenesis. MPT0B390 shows significant antiproliferative activity against the human colon cancer cell line HCT116, with a GI₅₀ of 0.03 μM, highlighting its potential as a promising candidate for cancer therapy.

Triacetin (Glyceryl triacetate) is an orally active synthetic triester of glycerol and acetic acid that serves as a bioavailable source of acetate. It freely crosses the blood–brain barrier and cellular membranes, making it particularly effective in targeting central nervous system malignancies. In glioma cells, Triacetin increases intracellular acetate levels, promotes histone acetylation, and induces cell cycle arrest and apoptosis. Additionally, Triacetin enhances the chemotherapeutic efficacy of Temozolomide (TMZ), supporting its potential as an adjuvant in glioma treatment strategies.

NT160 is a highly potent inhibitor of class IIa histone deacetylases (HDACs), with an IC₅₀ value of 0.046 μM. Due to its strong inhibitory activity and potential central nervous system (CNS) penetration, NT160 is a valuable compound for investigating the role of class IIa HDACs in CNS-related disorders, including neurodegenerative and neuropsychiatric diseases.

RSC133 is a dual epigenetic modulator that inhibits both histone deacetylases (HDACs) and DNA methyltransferases (DNMTs). It effectively enhances the reprogramming of human somatic cells into induced pluripotent stem cells (iPSCs) and supports the maintenance of pluripotency by promoting an undifferentiated state. RSC133 is a valuable tool for stem cell research and epigenetic reprogramming studies.

Alteminostat (CKD-581) is a potent, broad-spectrum histone deacetylase (HDAC) inhibitor that targets both class I and class II HDAC isoforms. It promotes histone H3 and α-tubulin acetylation, indicating effective inhibition of nuclear and cytoplasmic HDAC activity. Alteminostat is being investigated for its therapeutic potential in hematologic malignancies, including lymphoma and multiple myeloma, and serves as a valuable tool in epigenetic cancer research.

CG347B is a selective inhibitor of histone deacetylase 6 (HDAC6) and also serves as a structural scaffold in the synthesis of other metalloenzyme inhibitors. Due to its HDAC6 selectivity, CG347B is a valuable tool for research in oncology, immunology, and neurology, where HDAC6 plays key roles in regulating protein homeostasis, immune response, and neurodegenerative processes.

MC1742 is a potent pan-HDAC inhibitor with broad activity across multiple HDAC isoforms, exhibiting IC₅₀ values of 0.1 μM (HDAC1), 0.11 μM (HDAC2), 0.02 μM (HDAC3), 0.007 μM (HDAC6), 0.61 μM (HDAC8), 0.04 μM (HDAC10), and 0.1 μM (HDAC11). It effectively increases acetylation of histone H3 and α-tubulin, markers of HDAC inhibition. MC1742 inhibits the growth of cancer stem cells (CSCs), and induces growth arrest, apoptosis, and differentiation, particularly in sarcoma CSC models, making it a promising candidate for targeting therapy-resistant cancer cell populations.

SB-429201 is a potent and selective inhibitor of histone deacetylase 1 (HDAC1), with an IC₅₀ of approximately 1.5 μM. It exhibits at least a 20-fold selectivity for HDAC1 over other class I isoforms, including HDAC3 and HDAC8. SB-429201 serves as a valuable tool for studying HDAC1-specific functions and may have potential applications in epigenetic and cancer research.

Oleuropein Aglycone (3,4-DHPEA-EA) is a bioactive polyphenol and the aglycone form of oleuropein, generated through enzymatic, acidic, or acetylated hydrolysis. It exhibits a broad range of pharmacological effects. In a TgCRND8 transgenic mouse model of Alzheimer’s disease, dietary supplementation (50 mg/kg) increases neuronal autophagic vesicles, reverses cognitive deficits, and reduces histone deacetylase 2 (HDAC2) levels in the cortex and hippocampus. In a high-fat diet-induced obesity rat model, Oleuropein Aglycone elevates urinary norepinephrine, interscapular brown adipose tissue epinephrine, and UCP1 protein levels, while reducing plasma leptin levels and total abdominal fat mass. Additionally, in a carrageenan-induced pleurisy mouse model, it mitigates lung neutrophil infiltration, lipid peroxidation, and IL-1β production. These findings highlight its potential in neurodegenerative, metabolic, and inflammatory disease research.