Quercetin dihydrate for Antioxidation Anti-Inflammatory Immune Support and Free Radical Scavenging

1. Description

Quercetin dihydrate is a naturally occurring polyphenolic flavonoid compound widely found in various plant-based foods, such as apples, onions, berries, and red wine. Its molecular formula is C₁₅H₁₀O₇·2H₂O, and its molecular weight is approximately 338.27 Da. It appears as a yellow powder or yellow needle-like crystals with a melting point of 310–315°C. In terms of solubility, it is soluble in dimethyl sulfoxide (approximately 45–68 mg/mL) and ethanol (approximately 15–21 mg/mL), but is practically insoluble in water. It must be stored in a sealed container at low temperatures and protected from light; the powdered product can be stored for 3 years at –20°C. This compound exhibits cell membrane permeability and acts as an inhibitor of various kinases and enzymes, including PI3K, protein tyrosine kinases, mitochondrial ATPases, and phosphodiesterases. Additionally, it activates the longevity protein SIRT1 and promotes the survival of eukaryotic cells.

2. Application

(1) Analytical Standards and Research Tools: Used as analytical standards for content determination, pharmacological experiments, and bioactivity screening, as well as in research experiments such as cell delivery and enzyme activity assays.

(2) Oncology Research: Used to study the mechanisms of antiproliferation and apoptosis induction in various cancer cell lines (such as K562, Molt-4, Raji, and pancreatic cancer stem cells), exerting antitumor activity by inhibiting signaling pathways such as PI3K/Akt/mTOR.

(3) Antiviral Research: Used in in vitro studies of viral infections such as pseudorabies virus to explore its antiviral activity and mechanisms of action. Studies indicate that quercetin reduces viral titers in a dose-dependent manner (IC₅₀ = 2.618 μM).

(4) Neuroprotective Research: Used in research on neurological diseases, exerting neuroprotective effects through its antioxidant and anti-inflammatory activities.

(5) Metabolic and Cardiovascular Research: Investigated for potential applications in regulating lipid metabolism and improving metabolic disorders, involving the modulation of the STAT3 signaling pathway.

(6) Plant Biology Research: As a quinone reductase 2 (QR2) inhibitor, it is used to study plant metabolism and mechanisms related to antimalarial activity.

3. Main Efficacy

(1) Multi-target enzyme inhibitory activity: Effectively inhibits PI3K (IC₅₀ values of 2.4 μM, 3.0 μM, and 5.4 μM for PI3Kγ, PI3Kδ, and PI3Kβ, respectively); inhibits PIM1 kinase (IC₅₀ of 43 nM); inhibits phospholipase A2 (IC₅₀ of 2 μM); inhibits protein tyrosine kinase, mitochondrial ATPase, and phosphodiesterase activity.

(2) Antioxidant activity: As a polyphenolic flavonoid, it exhibits broad-spectrum antioxidant activity, scavenging free radicals and protecting cells from oxidative stress damage. Its anti-lipid peroxidation activity is 10–20 times that of vitamin E.

(3) Anti-inflammatory effects: It exerts anti-inflammatory effects by inhibiting inflammatory signaling pathways such as NF-κB and reducing the production of pro-inflammatory cytokines including tumor necrosis factor-α, interleukin-1β, and interleukin-6.

(4) Induction of apoptosis: It induces apoptosis in various tumor cell lines, including K562, Molt-4, and Raji, thereby exerting antitumor effects. It enhances the efficacy of chemotherapeutic drugs by inhibiting the PI3K signaling pathway and regulating lipid metabolism (e.g., by inhibiting CPT1B expression).

(5) Activation of SIRT1: It activates the longevity protein SIRT1, promoting eukaryotic cell survival, which is associated with anti-aging and cell protection mechanisms.

(6) Antiviral activity: Exhibits inhibitory effects against various viruses, including pseudorabies virus, and reduces viral titers in a dose-dependent manner (IC₅₀ = 2.618 μM). Additionally, it inhibits influenza A virus, enterovirus 71, and respiratory syncytial virus.

(7) Cell cycle regulation: Causes human T-cell leukemia cells to arrest in late G1 phase of the cell cycle, thereby inhibiting cell proliferation.

(8) Cardiovascular protection: It exerts cardiovascular protective effects through mechanisms such as inhibiting angiotensin-converting enzyme (ACE) activity, lowering blood pressure, improving endothelial function, and inhibiting platelet aggregation.

(9) Neuroprotective effects: Through mechanisms such as inhibiting acetylcholinesterase activity, reducing β-amyloid aggregation, and alleviating neuroinflammation, it demonstrates potential for improving cognitive function in Alzheimer’s disease models.