Isobavachalcone / Casp3 Cancer Research Results

Isobavachalcone - Prenylated Chalcone

Type: Natural prenylated chalcone / flavonoid-related phytochemical
-Chalcone → chemical class / parent scaffold, not a molecular target. -Example Chalones: Isobavachalcone, xanthohumol, licochalcone A, isoliquiritigenin

Sources: Found in several medicinal plants, particularly Psoralea corylifolia (Cullen corylifolium), as well as other plant species containing prenylated chalcones.

Function: Isobavachalcone is a bioactive prenylated chalcone with anticancer, anti-inflammatory, antioxidant, antimicrobial, and neuroprotective activities. Reported molecular effects include modulation of AKT, ERK/MAPK, ROS, apoptosis, inflammatory signaling, and cellular stress pathways.

Cancer: Experimental studies demonstrate inhibition of cancer-cell proliferation, migration, and invasion and induction of apoptosis and other forms of regulated cell death. IBC can suppress AKT and ERK signaling, increase tumor-cell oxidative stress, and modulate antitumor immune responses. Anticancer activity has been demonstrated in pancreatic, breast, oral, colorectal, thyroid, and other experimental cancer models.

Alzheimer's Disease: Preclinical studies indicate neuroprotective activity, including reduction of Aβ accumulation and plaque pathology, suppression of neuroinflammation, and improvement of memory and cognitive deficits in Alzheimer's disease models.

Isobavachalcone — Isobavachalcone (IBC; CAS 20784-50-3) is a naturally occurring prenylated chalcone and flavonoid-related phytochemical found particularly in Psoralea corylifolia L. (syn. Cullen corylifolium; Psoraleae Fructus/Bu Gu Zhi). It is an experimental small-molecule natural product with anticancer, anti-inflammatory, antimicrobial, and neuroprotective activities. Current anticancer evidence is preclinical and increasingly supports direct or proximal effects on SIRT2, DHODH, thioredoxin reductase 1, AKT signaling, mitochondrial function, and redox homeostasis. IBC has not been established as an approved anticancer or Alzheimer therapy.

Primary mechanisms (ranked):

1. Mitochondrial and redox disruption with ↑ ROS, mitochondrial membrane depolarization, impaired respiration/ATP production, mitochondrial Ca²⁺ overload, and activation of mitochondrial permeability-transition-associated cell death.
2. ↓ AKT signaling, including direct inhibition of AKT1 activity in early studies and suppression of AKT phosphorylation, reducing survival signaling and promoting mitochondrial apoptosis.
3. Direct ↓ SIRT2 activity, disrupting SIRT2/α-tubulin signaling and downstream STAT3/c-Myc and Snail/MMP pathways in triple-negative breast cancer.
4. ↓ DHODH with mitochondrial dysfunction, mtDNA release, ↑ ROS, and activation of cGAS-STING-associated antitumor immunity in gastric cancer models.
5. ↓ thioredoxin reductase 1, weakening cellular thioredoxin antioxidant capacity and promoting ROS-dependent ER stress and apoptosis in prostate cancer.
6. Induction of multiple regulated cell-death programs including mitochondrial apoptosis, non-canonical mitochondrial permeability-transition-driven necrosis, pyroptosis, necroptosis, and autophagy, depending on tumor model.
7. Suppression of invasion and metastatic signaling through pathways including ↓ β-catenin, ↓ MMP-2/MMP-9, ↓ Snail, and other context-dependent AKT/GSK-3β/β-catenin and SIRT2-associated mechanisms.
8. Antitumor immune modulation, including ↑ CD8+ T-cell infiltration, ↓ M2 macrophage polarization, and STING-associated innate immune activation in animal tumor models.
9. ABCB1 modulation and membrane perturbation, potentially increasing drug accumulation in some multidrug-resistant cancer cells.
10. Secondary NRF2/HO-1 activation has been reported primarily in anti-inflammatory/non-cancer contexts and should not be interpreted as the principal anticancer mechanism.

Bioavailability / PK relevance: Human pharmacokinetics have not been established. Rat oral pharmacokinetic studies demonstrate measurable systemic exposure after high oral dosing, but IBC undergoes extensive glucuronidation involving UGT1A1, UGT1A3 and additional UGT isoforms, with BCRP/MRP-mediated glucuronide efflux. These metabolic characteristics may limit free systemic exposure. IBC also inhibits multiple CYP and UGT enzymes in vitro at low-micromolar concentrations, creating a potential drug-interaction concern if therapeutically relevant human exposure can be achieved.

In-vitro vs systemic exposure relevance: Many anticancer experiments use approximately low- to several-tens-of-micromolar IBC concentrations; for example, MCF-7 growth inhibition has been reported at IC50 values around 28–38 µM, whereas direct SIRT2 inhibition occurs at substantially lower concentrations with an enzymatic IC50 of approximately 0.84 µM. Human plasma concentrations after oral dosing are unknown, so it cannot currently be assumed that the concentrations required for many cell-culture anticancer effects are clinically achievable. High-concentration mitochondrial ROS effects are particularly relevant to the hepatotoxicity signal and may narrow any therapeutic window.

Clinical evidence status: Preclinical. Anticancer activity has been demonstrated in numerous cancer cell systems and several mouse xenograft/allograft models, including breast, gastric, pancreatic, colorectal, prostate, AML, thyroid, and other cancers. No established human anticancer efficacy, therapeutic dose, validated exposure-response relationship, or regulatory approval has been demonstrated.

Safety: Hepatotoxicity is a significant translational constraint. IBC itself has produced mitochondrial dysfunction, ROS accumulation, loss of mitochondrial membrane potential, ATP depletion, apoptosis, and ferroptosis-associated injury in hepatic experimental systems. Psoralea corylifolia preparations are independently associated with clinically reported liver injury, although toxicity of the whole herb cannot be attributed exclusively to IBC. Potential CYP/UGT inhibition further raises concern for pharmacokinetic drug interactions.

Isobavachalcone Cancer-Relevant Mechanisms

Alzheimer's disease relevance: Isobavachalcone has meaningful but exclusively preclinical evidence in Alzheimer's disease. In transgenic AD mouse models, IBC has improved memory-related outcomes and reduced Aβ pathology, tau hyperphosphorylation, and neuroinflammation. More recent work links these effects to ↑ autophagic Aβ clearance and ↓ NLRP3 inflammasome activation in astrocytes. Earlier studies also identified inhibitory activity against several AD-associated targets, including Aβ42-related processes, BACE1, GSK-3β, and acetylcholinesterase. No human efficacy, dose, pharmacokinetic target, or clinical safety data support its use for AD.

Isobavachalcone Alzheimer-Relevant Mechanisms