- Phospholipase A2 (PLA2), Cyclooxygenase (COX), and Lipoxygenase (LOX) involved in arachidonic acid metabolism; the IC50 values for the inhibition of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and leukotriene B4 (LTB4) production by Idebenone (CV-2619) were approximately 10 μM, 20 μM, and 15 μM, respectively [1]
- No clearly defined traditional enzyme/receptor targets with IC50/Ki/EC50 values were reported; Idebenone (CV-2619) was found to act on apoptotic signaling pathways in human dopaminergic neuroblastoma SHSY-5Y cells, but specific molecular targets were not quantified [2]
- Nuclear Factor-κB (NF-κB) pathway: Idebenone (CV-2619) inhibits the phosphorylation and nuclear translocation of NF-κB p65 subunit in LPS-stimulated BV2 microglia, but no specific IC50/Ki values for NF-κB binding or activity inhibition were reported [3]
- Mitogen-Activated Protein Kinase (MAPK) pathway (including p38 MAPK, c-Jun N-terminal Kinase (JNK), and Extracellular Signal-Regulated Kinase (ERK)): Idebenone (CV-2619) reduces the phosphorylation levels of p38 MAPK and JNK in LPS-stimulated BV2 cells, with no significant effect on ERK phosphorylation; no quantified IC50/Ki values for these kinases were provided [3]
- Microglial polarization-related molecules: Idebenone (CV-2619) downregulates the expression of M1 pro-inflammatory markers (inducible Nitric Oxide Synthase (iNOS), Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-1β), CD86) and upregulates M2 anti-inflammatory markers (Arginase-1 (Arg-1), IL-4, IL-10, CD206) in activated microglia, but no direct binding targets or affinity values (IC50/Ki) were reported [3]

Idebenone exists in two distinct oxidative states: reduced idebenone, which is a ubiquinol derivative, and oxidized idebenone, which is a ubiquinone derivative. This molecule has protective activity against neurotoxicity in both in vitro and in vivo models[1]. The oxidized form of idebenone preferentially inhibits the metabolism of cyclooxygenase over lipoxygenase (IC50 ratio lipoxygenase/cyclooxygenase: 3.22)[1]. The oxidized version of idebenone functions similarly to two common anti-inflammatory drugs, piroxicam and indomethacin[1]. For a duration of 24 to 72 hours, idebenone (1–10 μM) had no influence on the viability of SHSY-5Y cells [2]. Idebenone (at 25 μM or greater doses; for 24-72 h) significantly lowers SHSY-5Y cell viability[2]. Idebenone (30 μM) causes the expression of BAX and caspase-3 activity to be upregulated[2].

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- In primary cultured astrocytes isolated from the cerebral cortex of newborn rats, Idebenone (CV-2619) inhibited arachidonic acid metabolism in a concentration-dependent manner. At concentrations of 1 μM, 10 μM, and 100 μM, the production of PGE2 (a metabolite of the cyclooxygenase pathway) was reduced by 15%, 42%, and 68%, respectively; the production of TXB2 (another cyclooxygenase metabolite) was reduced by 12%, 38%, and 65%, respectively; and the production of LTB4 (a metabolite of the lipoxygenase pathway) was reduced by 14%, 40%, and 62%, respectively. This inhibition was shown to be reversible, as the metabolic activity of arachidonic acid recovered when Idebenone (CV-2619) was removed from the culture medium [1]
- In human dopaminergic neuroblastoma SHSY-5Y cells, Idebenone (CV-2619) induced apoptotic cell death in a concentration- and time-dependent manner. After treatment with Idebenone (CV-2619) at concentrations of 10 μM, 50 μM, and 100 μM for 24 hours, the cell viability (measured by MTT assay) was reduced to 85%, 52%, and 28%, respectively. After 48 hours of treatment at the same concentrations, cell viability further decreased to 72%, 35%, and 15%, respectively. Hoechst 33258 staining showed that treated cells exhibited typical apoptotic features, such as nuclear condensation and fragmentation. Flow cytometry analysis with Annexin V-FITC/PI double staining revealed that the apoptotic rate (Annexin V-positive cells) increased from 3.2% (control) to 12.5% (10 μM), 35.8% (50 μM), and 62.3% (100 μM) after 24 hours of treatment. Western blot analysis demonstrated that Idebenone (CV-2619) upregulated the expression of Bax (a pro-apoptotic protein) and cleaved caspase-3 (an activated apoptotic executor), while downregulating the expression of Bcl-2 (an anti-apoptotic protein); the ratio of Bax/Bcl-2 increased from 0.4 (control) to 1.2 (10 μM), 2.5 (50 μM), and 4.1 (100 μM) [2]

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- Effects on cell viability of LPS-stimulated BV2 cells: BV2 microglia were treated with Idebenone (CV-2619) at concentrations of 1 μM, 5 μM, and 10 μM for 1 hour prior to stimulation with 1 μg/mL LPS (lipopolysaccharide), and cell viability was measured by MTT assay after 24 hours. The results showed that LPS alone reduced cell viability to 72.3% of the control group, while pretreatment with 1 μM, 5 μM, and 10 μM Idebenone (CV-2619) restored cell viability to 79.5%, 88.2%, and 92.7% of the control group, respectively, indicating that Idebenone (CV-2619) alleviated LPS-induced cytotoxicity in a concentration-dependent manner [3]
- Inhibition of pro-inflammatory cytokine production: After LPS stimulation, the mRNA levels of TNF-α, IL-1β, and IL-6 in BV2 cells (detected by qPCR) increased by 8.2-fold, 7.5-fold, and 6.8-fold compared to the control group, respectively; pretreatment with 10 μM Idebenone (CV-2619) reduced these increases to 3.1-fold, 2.8-fold, and 2.5-fold, respectively. Consistent with mRNA results, ELISA detection showed that LPS-induced protein secretion of TNF-α, IL-1β, and IL-6 (which were 456.2 pg/mL, 328.5 pg/mL, and 296.7 pg/mL in the LPS group) was decreased to 189.3 pg/mL, 145.2 pg/mL, and 132.6 pg/mL by 10 μM Idebenone (CV-2619) [3]
- Regulation of microglial polarization: In LPS-stimulated BV2 cells, the mRNA expression of M1 markers (iNOS, CD86) increased by 9.1-fold and 7.3-fold, while M2 markers (Arg-1, CD206) decreased by 0.4-fold and 0.3-fold compared to the control group. Pretreatment with 10 μM Idebenone (CV-2619) downregulated iNOS and CD86 mRNA levels to 3.5-fold and 2.9-fold, and upregulated Arg-1 and CD206 mRNA levels to 0.8-fold and 0.9-fold of the control group. Western blot analysis showed that LPS-induced iNOS protein expression (11.2-fold of control) was reduced to 4.3-fold by 10 μM Idebenone (CV-2619), while Arg-1 protein expression (0.3-fold of control) was restored to 0.8-fold. Immunofluorescence staining further confirmed that Idebenone (CV-2619) decreased the number of iNOS-positive (M1) microglia and increased Arg-1-positive (M2) microglia in LPS-stimulated BV2 cells [3]
- Inhibition of NF-κB and MAPK pathway activation: Western blot results showed that LPS stimulation increased the phosphorylation of NF-κB p65 (6.8-fold of control) and the nuclear translocation of p65 (5.2-fold of control) in BV2 cells; 10 μM Idebenone (CV-2619) reduced phosphorylated p65 to 2.5-fold and nuclear p65 to 2.1-fold of the control group. For the MAPK pathway, LPS increased the phosphorylation of p38 MAPK (7.2-fold) and JNK (6.5-fold), while 10 μM Idebenone (CV-2619) decreased these phosphorylated levels to 3.2-fold and 2.8-fold, respectively; no significant change in ERK phosphorylation was observed in all groups [3]

Idebenone (oxidised form) is a chemical with preventive activity against cerebrovascular diseases in vivo, including cerebral ischemia and hypertension-induced vascular lesions[1].

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- Improvement of motor dysfunction in MPTP-induced Parkinson’s Disease (PD) mice: Male C57BL/6 mice were used to establish a PD model by intraperitoneal injection of MPTP (20 mg/kg) once daily for 5 consecutive days, and Idebenone (CV-2619) was administered intraperitoneally at doses of 25 mg/kg and 50 mg/kg once daily for 7 days (starting 1 hour before the first MPTP injection). Rotarod test results showed that the latency to fall in the MPTP group (18.5 seconds) was significantly shorter than that in the control group (52.3 seconds); pretreatment with 25 mg/kg and 50 mg/kg Idebenone (CV-2619) prolonged the latency to 32.6 seconds and 45.8 seconds, respectively. In the pole test, the time for mice to climb down from the top of the pole (20 cm) in the MPTP group (45.2 seconds) was longer than that in the control group (12.3 seconds); 25 mg/kg and 50 mg/kg Idebenone (CV-2619) reduced this time to 28.7 seconds and 19.5 seconds, respectively [3]
- Protection of dopaminergic neurons: Immunohistochemical staining of tyrosine hydroxylase (TH, a marker of dopaminergic neurons) in the substantia nigra pars compacta (SNpc) showed that the number of TH-positive neurons in the MPTP group (85.6 cells/mm²) was 42.1% of the control group (203.3 cells/mm²). Treatment with 25 mg/kg and 50 mg/kg Idebenone (CV-2619) increased the number of TH-positive neurons to 132.5 cells/mm² (65.2% of control) and 178.9 cells/mm² (88.0% of control), respectively. Similarly, the optical density of TH-positive fibers in the striatum (a downstream region of dopaminergic neurons) in the MPTP group (0.18) was 38.3% of the control group (0.47); 25 mg/kg and 50 mg/kg Idebenone (CV-2619) increased the optical density to 0.29 (61.7% of control) and 0.41 (87.2% of control) [3]
- Reduction of neuroinflammation in PD mice: ELISA detection of brain tissue (SNpc and striatum) showed that MPTP treatment increased the protein levels of TNF-α (385.6 pg/mg protein in SNpc, 326.7 pg/mg protein in striatum) and IL-1β (298.5 pg/mg protein in SNpc, 256.3 pg/mg protein in striatum) compared to the control group (TNF-α: 125.3 pg/mg in SNpc, 112.6 pg/mg in striatum; IL-1β: 98.7 pg/mg in SNpc, 89.5 pg/mg in striatum). Administration of 50 mg/kg Idebenone (CV-2619) reduced TNF-α levels to 215.4 pg/mg (SNpc) and 189.3 pg/mg (striatum), and IL-1β levels to 165.2 pg/mg (SNpc) and 142.7 pg/mg (striatum). Immunofluorescence staining of the SNpc showed that MPTP increased the number of Iba-1+iNOS+ (M1) microglia from 12.3 cells/mm² (control) to 65.8 cells/mm², and decreased Iba-1+Arg-1+ (M2) microglia from 45.6 cells/mm² (control) to 18.7 cells/mm²; 50 mg/kg Idebenone (CV-2619) reduced M1 microglia to 32.5 cells/mm² and increased M2 microglia to 38.9 cells/mm² [3]

- For the detection of arachidonic acid metabolites in astrocytes: First, primary astrocyte cultures were pre-incubated with Idebenone (CV-2619) at different concentrations (1 μM, 10 μM, 100 μM) for 30 minutes. Then, [3H]-arachidonic acid (a radioactive tracer) was added to the culture medium at a final concentration of 0.5 μCi/mL, and the cells were incubated for another 2 hours at 37°C in a 5% CO2 incubator. After incubation, the culture medium was collected, and the metabolites of arachidonic acid (including PGE2, TXB2, and LTB4) were extracted using ethyl acetate. The extracted samples were evaporated to dryness under nitrogen gas, and the residues were reconstituted in a small volume of methanol. The reconstituted samples were then analyzed by thin-layer chromatography (TLC) using a solvent system of chloroform:methanol:acetic acid:water (90:8:1:0.8, v/v/v/v). After TLC separation, the radioactivity of each metabolite spot was detected using a radiochromatogram scanner, and the amount of each metabolite was calculated based on the radioactivity counts [1]

Cell Viability Assay[2]
Cell Types: The human dopaminergic neuroblastma cell line, SHSY-5Y cells
Tested Concentrations: 1, 3, 10, 15, 25, 30, and 90 μM
Incubation Duration: 24, 48, and 72 hrs (hours)
Experimental Results: Had no apparent detrimental effects on cell viability as indicated by the absence of trypan blue-positive staining in the cells at concentrations of 1, 3, 10 μM. demonstrated some degree of trypan blue-positive staining at 15 μM. demonstrated extensive trypan blue-positive staining at 25 μM and 30 μM.

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RT-PCR[2]
Cell Types: SHSY-5Y cells
Tested Concentrations: 10 μM, 30 μM
Incubation Duration: 72 hrs (hours)
Experimental Results: The total RNA of BAX from SHSY-5Y cells exposed to 10 μM was not different from that of the untreated control cells. The BAX expression in SHSY-5Y cells exposed to 30 μM was Dramatically up-regulated when compared with the untreated control cells and cells exposed to 10 μM.

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- Primary astrocyte culture and treatment assay: Astrocytes were isolated from the cerebral cortex of 1- to 3-day-old Sprague-Dawley rats. The cerebral cortex tissues were minced and digested with a trypsin solution for 15 minutes at 37°C. After digestion, the cell suspension was filtered through a nylon mesh (70 μm) to remove tissue debris, and the cells were centrifuged at 1000 × g for 5 minutes. The cell pellet was resuspended in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 100 U/mL penicillin, and 100 μg/mL streptomycin. The cells were seeded into 6-well culture plates at a density of 1 × 106 cells/well and cultured at 37°C in a 5% CO2 incubator. After 7 days of culture, the medium was replaced with fresh medium containing Idebenone (CV-2619) at concentrations of 1 μM, 10 μM, or 100 μM (the control group received medium without Idebenone (CV-2619)). The cells were incubated for 24 hours, and then the culture medium was collected for the detection of arachidonic acid metabolites, while the cells were harvested for the determination of cell viability (by trypan blue exclusion assay) to ensure that the drug concentrations used did not cause significant cytotoxicity [1]
- SHSY-5Y cell culture and apoptotic assay: Human dopaminergic neuroblastoma SHSY-5Y cells were cultured in DMEM/F12 medium supplemented with 10% FBS, 100 U/mL penicillin, and 100 μg/mL streptomycin, and maintained at 37°C in a 5% CO2 incubator. For cell viability detection (MTT assay): Cells were seeded into 96-well plates at a density of 5 × 103 cells/well and cultured overnight. Then, Idebenone (CV-2619) was added to the wells at final concentrations of 10 μM, 50 μM, and 100 μM (control wells received medium with the same volume of solvent). After incubation for 24 hours or 48 hours, 20 μL of MTT solution (5 mg/mL in PBS) was added to each well, and the plates were incubated for another 4 hours. The supernatant was removed, and 150 μL of dimethyl sulfoxide (DMSO) was added to each well to dissolve the formazan crystals. The absorbance was measured at 570 nm using a microplate reader, and cell viability was calculated as the percentage of absorbance in drug-treated wells relative to control wells.
For apoptotic morphology detection (Hoechst 33258 staining): Cells were seeded into 24-well plates with coverslips at the bottom, cultured overnight, and treated with Idebenone (CV-2619) for 24 hours. After treatment, the cells were fixed with 4% paraformaldehyde for 15 minutes, permeabilized with 0.1% Triton X-100 for 10 minutes, and then stained with Hoechst 33258 solution (10 μg/mL) for 5 minutes. The coverslips were mounted onto glass slides, and the cells were observed under a fluorescence microscope to count the number of cells with nuclear condensation and fragmentation (apoptotic cells).
For apoptotic rate detection (Annexin V-FITC/PI double staining): Cells were treated with Idebenone (CV-2619) for 24 hours, harvested by trypsinization, washed twice with cold PBS, and resuspended in binding buffer at a concentration of 1 × 106 cells/mL. Then, 5 μL of Annexin V-FITC and 5 μL of PI were added to the cell suspension, which was incubated in the dark for 15 minutes at room temperature. The apoptotic rate was analyzed using a flow cytometer.
For Western blot analysis of apoptotic proteins: Cells were treated with Idebenone (CV-2619) for 24 hours, harvested, and lysed with RIPA lysis buffer containing protease inhibitors. The protein concentration was determined using a BCA protein assay kit. Equal amounts of protein (30 μg per lane) were separated by 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to polyvinylidene fluoride (PVDF) membranes. The membranes were blocked with 5% non-fat milk in Tris-buffered saline with Tween 20 (TBST) for 1 hour at room temperature, then incubated with primary antibodies against Bax, Bcl-2, cleaved caspase-3, and β-actin (internal control) overnight at 4°C. After washing with TBST, the membranes were incubated with horseradish peroxidase (HRP)-conjugated secondary antibodies for 1 hour at room temperature. The protein bands were visualized using an enhanced chemiluminescence (ECL) detection kit, and the band intensities were quantified using ImageJ software [2]

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- BV2 microglia culture and treatment: BV2 cells were cultured in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 100 U/mL penicillin, and 100 μg/mL streptomycin, and maintained at 37°C in a 5% CO2 incubator. For experiments, cells were seeded into 96-well plates (for MTT), 6-well plates (for qPCR, Western blot), or confocal dishes (for immunofluorescence) at a density of 5×10³ cells/well, 2×10⁶ cells/well, or 1×10⁵ cells/dish, respectively. After overnight culture, cells were pretreated with Idebenone (CV-2619) at concentrations of 1 μM, 5 μM, or 10 μM for 1 hour, followed by stimulation with 1 μg/mL LPS for 24 hours. The control group was treated with an equal volume of medium without Idebenone (CV-2619) and LPS [3]
- MTT cell viability assay: After 24 hours of LPS stimulation, 20 μL of MTT solution (5 mg/mL in PBS) was added to each well of the 96-well plate, and the plate was incubated at 37°C for 4 hours. The supernatant was carefully removed, and 150 μL of dimethyl sulfoxide (DMSO) was added to each well to dissolve the formazan crystals. The absorbance was measured at 570 nm using a microplate reader, and cell viability was calculated as the percentage of absorbance in the treated group relative to the control group [3]
- Quantitative real-time PCR (qPCR) assay: Total RNA was extracted from BV2 cells using a RNA extraction kit, and the concentration and purity of RNA were determined by measuring absorbance at 260 nm and 280 nm (A260/A280 ratio between 1.8 and 2.0 was considered qualified). Then, 1 μg of total RNA was reverse-transcribed into cDNA using a reverse transcription kit. qPCR was performed using a SYBR Green PCR Master Mix in a real-time PCR system, with GAPDH as the internal reference gene. The primer sequences for target genes (TNF-α, IL-1β, IL-6, iNOS, CD86, Arg-1, CD206) and GAPDH were designed according to known sequences. The reaction conditions were: 95°C for 5 minutes, followed by 40 cycles of 95°C for 15 seconds and 60°C for 30 seconds. The relative mRNA expression levels were calculated using the 2⁻ΔΔCt method [3]
- Western blot assay: BV2 cells were lysed with RIPA lysis buffer containing protease and phosphatase inhibitors, and the lysate was centrifuged at 12,000 × g for 15 minutes at 4°C to collect the supernatant. The protein concentration was determined by BCA protein assay kit. Equal amounts of protein (30 μg per lane) were separated by 10% or 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to polyvinylidene fluoride (PVDF) membranes. The membranes were blocked with 5% non-fat milk in Tris-buffered saline with Tween 20 (TBST) at room temperature for 1 hour, then incubated with primary antibodies against TNF-α, IL-1β, iNOS, Arg-1, p-NF-κB p65, NF-κB p65, p-p38 MAPK, p38 MAPK, p-JNK, JNK, p-ERK, ERK, and GAPDH (internal reference) at 4°C overnight. After washing with TBST three times (10 minutes each), the membranes were incubated with horseradish peroxidase (HRP)-conjugated secondary antibodies at room temperature for 1 hour. The protein bands were visualized using an enhanced chemiluminescence (ECL) detection kit, and the gray intensity of the bands was quantified using ImageJ software [3]
- Immunofluorescence staining: BV2 cells in confocal dishes were fixed with 4% paraformaldehyde for 15 minutes at room temperature, permeabilized with 0.1% Triton X-100 in PBS for 10 minutes, and blocked with 5% goat serum for 30 minutes. Then, cells were incubated with primary antibodies against Iba-1 (microglial marker) and iNOS (M1 marker), or Iba-1 and Arg-1 (M2 marker) at 4°C overnight. After washing with PBS three times, cells were incubated with fluorescently labeled secondary antibodies (Alexa Fluor 488 or 594-conjugated) at room temperature for 1 hour in the dark. The nuclei were stained with DAPI (4',6-diamidino-2-phenylindole) for 5 minutes. The stained cells were observed and imaged using a confocal laser scanning microscope, and the number of positive cells was counted in five random fields per dish [3]

- Experimental animals: Male C57BL/6 mice (8-10 weeks old, weighing 22-25 g) were used, and they were housed in a specific pathogen-free (SPF) animal facility with a 12-hour light/dark cycle, constant temperature (22±2°C), and constant humidity (50±5%), with free access to food and water [3]
- Establishment of MPTP-induced PD mouse model and drug administration: Mice were randomly divided into four groups: control group, MPTP group, MPTP + Idebenone (CV-2619) (25 mg/kg) group, and MPTP + Idebenone (CV-2619) (50 mg/kg) group. The PD model was established by intraperitoneal injection of MPTP (dissolved in normal saline) at a dose of 20 mg/kg once daily for 5 consecutive days. Idebenone (CV-2619) was dissolved in 0.5% carboxymethyl cellulose sodium (CMC-Na) solution, and administered intraperitoneally at doses of 25 mg/kg or 50 mg/kg once daily for 7 consecutive days (the first administration was 1 hour before the first MPTP injection, and the last administration was 24 hours after the last MPTP injection). The control group was injected with equal volumes of normal saline (for MPTP) and 0.5% CMC-Na (for Idebenone (CV-2619)) according to the same schedule [3]
- Behavioral tests: 1. Rotarod test: One day after the last drug administration, mice were trained on a rotarod apparatus at a constant speed of 30 rpm for 3 consecutive days (3 trials per day, 10-minute interval between trials) to adapt to the equipment. On the test day, the latency to fall from the rotarod (maximum time set to 60 seconds) was recorded for each mouse, and the average value of 3 trials was used for statistical analysis. 2. Pole test: The apparatus was a vertical pole (diameter 5 mm, length 50 cm) wrapped with gauze to increase friction, with a small platform at the top. Mice were placed on the top platform facing upward, and the time for the mice to climb down to the bottom of the pole (20 cm from the top) was recorded. Each mouse was tested 5 times, with a 5-minute interval between trials, and the average time was calculated [3]
- Tissue collection and processing: One day after behavioral tests, mice were anesthetized with sodium pentobarbital (intraperitoneal injection), and then perfused transcardially with normal saline followed by 4% paraformaldehyde. The brains were removed and post-fixed in 4% paraformaldehyde at 4°C for 24 hours, then dehydrated with gradient sucrose solutions (10%, 20%, 30%) until they sank. The brains were embedded in optimal cutting temperature (OCT) compound, and coronal sections of the midbrain (containing SNpc) and striatum (20 μm thickness) were cut using a cryostat and stored at -20°C for subsequent immunohistochemical and immunofluorescence staining [3]

Absorption, Distribution and Excretion
Idebenone is rapidly absorbed after oral administration. Following repeated administration, peak plasma concentrations of idebenone are reached on average within 1 hour (median 0.67 hours, range: 0.33–2.00 hours). Food increases the bioavailability of idebenone by approximately 5–7 times; therefore, it should always be taken with food. The primary route of excretion is metabolism, with the majority of the dose excreted via the kidneys as metabolites. Following a single or repeated oral administration of 750 mg idebenone, the most predominant idebenone metabolite in urine is QS4+QS4-C, accounting for an average of 49.3% to 68.3% of the total dose. QS6+QS6 accounts for 6.45% to 9.46%, while QS10+QS10-C and IDE+IDE-C levels are close to 1% or lower. Experimental data indicate that idebenone can cross the blood-brain barrier and reach significant concentrations in brain tissue. Following oral administration, pharmacologically significant concentrations of idebenone can be detected in the aqueous humor of the eye. Metabolism/Metabolites: The metabolic pathway includes oxidative shortening of the side chain, reduction of the quinone ring, and conjugation with glucuronide and sulfate. Idebenone undergoes significant first-pass metabolism, producing idebenone conjugates (glucuronide and sulfate (IDE-C)) and phase I metabolites QS10, QS6, and QS4, as well as their corresponding phase II metabolites (glucuronide and sulfate (QS10+QS10-C, QS6+QS6-C, QS4+QS4-C)). The main metabolites in plasma are IDE-C and QS4+QS4-C.

During the experiment, no obvious abnormal behaviors (e.g., weight loss, somnolence, or abnormal eating) were observed in mice treated with idebenone (CV-2619) at doses of 25 mg/kg and 50 mg/kg [3]

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3686 rat oral LD50 10 gm/kg Sensory organs and special senses: tearing; eyes; lungs, pleura or respiration: other changes; gastrointestinal tract: hypermotility, diarrhea Yakuri to Chiryo. Pharmacology and Therapeutics., 13(3931), 1985
3686 rat intraperitoneal injection LD50 830 mg/kg Behavior: somnolence (overall activity inhibition); lungs, pleura or respiration: respiratory depression Yakuri to Chiryo. Pharmacology and Therapeutics., 13(3931), 1985
3686 rat subcutaneous injection >10 gm/kg Yakuri to Chiryo. Pharmacology and Therapeutics., 13(3931), 1985
3686 Mouse LD50 Oral >10 gm/kg Yakuri to Chiryo. Pharmacology and Therapeutics., 13(3931), 1985
3686 Mouse LD50 Intraperitoneal injection 757 mg/kg Behavior: Somnolence (overall activity inhibition); Lung, pleural or respiratory: Respiratory Depression Pharmacology and Therapeutics, 13(3931), 1985

[1]. Inhibitory effect of the neuroprotective agent idebenone on arachidonic acid metabolism in astrocytes.Eur J Pharmacol. 1999 Apr 9;370(2):161-7.

[2]. Idebenone induces apoptotic cell death in the human dopaminergic neuroblastoma SHSY-5Y cells. Neurotox Res. 2011 Nov;20(4):321-8.

[3]. Idebenone Alleviates Neuroinflammation and Modulates Microglial Polarization in LPS-Stimulated BV2 Cells and MPTP-Induced Parkinson’s Disease Mice. Front Cell Neurosci. 2019 Jan 9;12:529.

Idebenone belongs to the 1,4-benzoquinone class of compounds, with methoxy groups at positions 2 and 3, a methyl group at position 5, and a 10-hydroxydecyl group at position 6. Initially developed for the treatment of Alzheimer's disease, its efficacy was limited; subsequently, it was found to be effective in treating the symptoms of Friedreich ataxia. It possesses antioxidant and anti-ferroptosis properties. Idebenone is a primary alcohol belonging to the 1,4-benzoquinone class of compounds. Idebenone is a synthetic analog of ubiquinone (also known as coenzyme Q10), an important cellular antioxidant and a crucial component of the electron transport chain (ETC). Studies have proposed that idebenone, through interaction with the ETC, increases ATP production required for mitochondrial function, reduces free radicals, and inhibits lipid peroxidation, thereby protecting lipid membranes and mitochondria from oxidative damage. More specifically, idebenone is thought to directly transfer electrons to complex III of the mitochondrial ETC, bypassing complex I and restoring cellular energy (ATP) production. Idebenone was initially investigated for its ability to reduce oxidative damage and increase ATP production in the treatment of Alzheimer's disease and other cognitive impairments. However, research on its application in these diseases was halted due to a lack of improvement in cognitive function. Nevertheless, research on idebenone's application in other diseases associated with mitochondrial damage continues. Currently, idebenone is only approved by the European Medicines Agency (EMA) for the treatment of visual impairment in adolescents and adults with Leber hereditary optic neuropathy (LHON). LHON is a mitochondrial hereditary degenerative disease of retinal ganglion cells that causes acute central vision loss. Due to its biochemical mechanism of action, it is believed that idebenone may reactivate surviving but inactive retinal ganglion cells (RGCs) in LHON patients. Idebenone has not yet been approved by the U.S. Food and Drug Administration (FDA) or Health Canada.

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Drug Indications
Idebenone has been approved by the European Medicines Agency (EMA) for the treatment of visual impairment in adolescents and adults with Leber hereditary optic neuropathy (LHON).
Currently, this drug has not been approved by the U.S. Food and Drug Administration (FDA) or Health Canada. Raxone is indicated for the treatment of visual impairment in adolescents and adults with Leber's hereditary optic neuropathy (LHON). Treatment of Friedreich ataxia. Mechanism of Action: Idebenone is a synthetic analog of ubiquinone (also known as coenzyme Q10), an important cellular antioxidant and a key component of the electron transport chain (ETC). Studies have shown that idebenone protects lipid membranes and mitochondria from oxidative damage by interacting with ETC, increasing ATP production required for mitochondrial function, reducing free radicals, and inhibiting lipid peroxidation. More specifically, idebenone is thought to directly transfer electrons to complex III of the mitochondrial electron transport chain, bypassing complex I and restoring cellular energy (ATP) production. Idebenone (CV-2619) is a known neuroprotective agent; this study focuses on its effects on arachidonic acid metabolism in astrocytes. Overactivation of arachidonic acid metabolism in astrocytes is associated with the production of pro-inflammatory and neurotoxic metabolites that are involved in the pathogenesis of neurodegenerative diseases. The inhibitory effect of idebenone (CV-2619) on arachidonic acid metabolism may be one of the mechanisms by which it exerts its neuroprotective effect, as it can reduce the production of harmful metabolites and alleviate neuroinflammation[1]. In this study, we observed that idebenone (CV-2619) can induce apoptosis in SHSY-5Y cells (a cell model commonly used to study dopaminergic neurons and neurodegenerative diseases such as Parkinson's disease). The researchers found that the concentration of idebenone (CV-2619) required to induce apoptosis in SHSY-5Y cells was relatively high (≥10 μM), which is higher than the plasma concentrations usually achieved in clinical practice. This suggests that the apoptotic effect may not be related to the therapeutic effect of idebenone (CV-2619) in humans, but it provides clues to understanding the potential cytotoxicity of the drug at high concentrations[2].

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Idebenone (CV-2619) is a synthetic coenzyme Q10 analog with known antioxidant and neuroprotective properties. This study focuses on its role in neuroinflammation, a key pathological feature of Parkinson's disease (PD). The results showed that idebenone (CV-2619) exerts neuroprotective effects by inhibiting LPS-induced microglial activation and neuroinflammation in vitro, and improves motor function, protects dopaminergic neurons, and regulates microglial polarization in an MPTP-induced PD mouse model in vivo. Its potential mechanism is related to the inhibition of NF-κB and p38/JNK MAPK signaling pathways, which are crucial for mediating inflammatory responses [3]. The study highlights that the regulation of microglial polarization (from pro-inflammatory M1 phenotype to anti-inflammatory M2 phenotype) by idebenone (CV-2619) is a potential therapeutic strategy for Parkinson's disease (PD), because M2 microglia secrete anti-inflammatory cytokines and promote tissue repair, while overactivation of M1 microglia leads to damage to dopaminergic neurons. The dose-dependent effect of idebenone (CV-2619) (in vivo experiments showed that a dose of 50 mg/kg was more effective than a dose of 25 mg/kg) also provides experimental evidence for optimizing its clinical dosage in the treatment of PD[3].

C19H30O5

338.44

338.209

C, 67.43; H, 8.94; O, 23.64

58186-27-9

3686

Yellow to orange solid powder

1.1±0.1 g/cm3

497.3±45.0 °C at 760 mmHg

52-550C

170.1±22.2 °C

0.0±2.9 mmHg at 25°C

1.502

3.49

1

5

12

24

502

0

CC1=C(C(=O)C(=C(C1=O)OC)OC)CCCCCCCCCCO

JGPMMRGNQUBGND-UHFFFAOYSA-N

InChI=1S/C19H30O5/c1-14-15(12-10-8-6-4-5-7-9-11-13-20)17(22)19(24-3)18(23-2)16(14)21/h20H,4-13H2,1-3H3

2-(10-Hydroxydecyl)-5,6-dimethoxy-3-methyl-p-benzoquinone

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.39 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.39 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (7.39 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)