Didymin

Didymin is a flavonoid glycoside found in citrus fruits that displays antioxidative and anticancer chemotherapeutic activities. In cellular and animal models of non-small cell lung cancer (NSCLC), didymin induces Fas-mediated apoptosis and delays tumor growth. Additionally, didymin downregulates PI3K, pAkt, Akt, and vimentin expression and decreases levels of CDK4, n-Myc, and cyclins B1 and D1 in vitro. In animal models of neuroblastoma, didymin decreases tumor size.

Human Biological Effects

Didymin (isosakuranetin 7-\(O\)-rutinoside) is an orally bioactive dietary flavonoid glycoside found primarily in citrus fruits (such as oranges, mandarins, and lemons). Preclinical pharmacological research indicates that it exhibits several significant biological activities in human cellular models and animal tissues.

1. Anti-Inflammatory and Immune Regulation

• Inhibiting Inflammatory Pathways: Didymin exerts potent anti-inflammatory effects primarily by suppressing key inflammatory cascades, such as the NF-\(\kappa\)B signaling pathway, which decreases the expression and release of pro-inflammatory cytokines.
• Inflammasome Suppression: Studies on tissue injury demonstrate that didymin can block the activation of the NLRP3 inflammasome (including reductions in ASC and caspase-1 expression), mitigating acute tissue damage and chronic low-grade inflammation.

2. Cardiovascular and Endothelial Protection

• Endothelial Function: In human umbilical vein endothelial cells (HUVECs), didymin has been shown to protect against hyperglycemia-induced oxidative stress, cytotoxicity, and cellular apoptosis, helping to preserve normal vascular endothelial integrity.
• Myocardial and Ischemic Relief: Preclinical models of myocardial infarction and ischemia-reperfusion injury indicate that didymin reduces infarct size, limits cardiac fibrosis, and suppresses cellular apoptosis by modulating apoptotic regulatory proteins (such as increasing anti-apoptotic Bcl-2 while decreasing pro-apoptotic Bax).

3. Metabolic Regulation and Insulin Sensitivity

• Glucose Uptake: In insulin-resistant human liver cells (such as HepG2 models), didymin promotes glucose consumption and uptake.
• Enzyme Modulation: Research suggests it interacts with molecular targets in metabolic pathways, acting as an antagonist to protein tyrosine phosphatase 1B (PTP1B) while activating the PI3K/Akt signaling pathway, which helps counter insulin resistance.

4. Anticancer and Pro-Apoptotic Effects

• Inducing Cancer Cell Apoptosis: In human cancer cell lines (most notably non-small-cell lung cancer and neuroblastoma models), didymin has demonstrated anti-proliferative capabilities.
• Receptor-Mediated Death: It can trigger apoptosis via death receptor pathways (such as Fas-mediated signaling) and downregulate survival pathways like ERK and PI3K/Akt.

5. Hepatoprotection and Fibrosis Prevention

• Hepatic Stellate Cells: Didymin helps prevent or alleviate liver fibrosis by regulating Raf kinase inhibitor protein (RKIP) expression, which subsequently inhibits fibrogenic signaling loops like the ERK and PI3K/Akt pathways in hepatic cells.

Note: While these in vitro and animal model findings highlight significant therapeutic potential, didymin remains primarily in the stage of laboratory and preclinical investigation, and comprehensive human clinical trial data are still limited.

ARTICLES/STUDIES

Recent trends in potential therapeutic applications of the dietary flavonoid didymin

Cancer

• Didymin, a dietary flavonoid glycoside from citrus fruits, induces Fas-mediated apoptotic pathway in human non-small-cell lung cancer cells in vitro and in vivo
• The flavonoid didymin, isolated from Origanum vulgare induces apoptosis in HepG2 cells through mitochondrial dysfunction.
• Didymin induces apoptosis by inhibiting N-Myc and upregulating RKIP in neuroblastoma
• Novel flavonoid didymin inhibits neuroblastomas
• Novel Flavonoid Didymin Inhibits Neuroblastomas—Response
• Anticancer effects and mechanisms of action of novel flavonoid didymin in neuroblastomas
• Didymin by suppressing NF-κB activation prevents VEGF-induced angiogenesis in vitro and in vivo
• Didymin induces apoptosis through mitochondrial dysfunction and up-regulation of RKIP in human hepatoma cells
• Didymin reverses phthalate ester-associated breast cancer aggravation in the breast cancer tumor microenvironment
• Didymin: an orally active citrus flavonoid for targeting neuroblastoma

Diabetes

Didymin, a dietary citrus flavonoid exhibits anti-diabetic complications and promotes glucose uptake through the activation of PI3K/Akt signaling pathway in insulin …

Endothelial Dysfunction

Didymin prevents hyperglycemia-induced human umbilical endothelial cells dysfunction and death

Hepatoprotective

• Didymin alleviates hepatic fibrosis through inhibiting ERK and PI3K/Akt pathways via regulation of Raf kinase inhibitor protein
• Didymin ameliorates hepatic injury through inhibition of MAPK and NF-κB pathways by up-regulating RKIP expression
• Didymin ameliorates dexamethasone-induced non-alcoholic fatty liver disease by inhibiting TLR4/NF-κB and PI3K/Akt pathways in C57BL/6J mice

Neuroprotective

Neuroprotective effect of didymin on hydrogen peroxide-induced injury in the neuronal membrane system