OG-L002 is a novel selective inhibitor of lysine-specific demethylase 1 (LSD1/KDM1A), an enzyme that catalyzes the demethylation of histone H3 lysine 4 (H3K4) and lysine 9 (H3K9). The IC50 value for inhibiting recombinant human LSD1/KDM1A activity is 150 nM. It shows no significant inhibitory activity (IC50 >10 μM) against other histone demethylases (e.g., JMJD2A, JMJD3) or histone acetyltransferases, confirming its selectivity for LSD1/KDM1A [1]

In comparison to the control MAOI TCP (IC50: ~1 mM), OG-L002 greatly reduces the IE gene expression of the virus in both cells (IC50: ~10 µM in HeLa cells and ~3 µM in HFF cells)[1].

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Inhibition of LSD1/KDM1A enzymatic activity: OG-L002 (0.01-10 μM) inhibits LSD1/KDM1A-mediated demethylation of H3K4me2 (dimethylated H3K4) in a concentration-dependent manner. At 1 μM, it reduces LSD1 activity by 85±6% compared to the vehicle control, as measured by a fluorescent-based demethylase assay [1]
- Blockade of herpes simplex virus (HSV) lytic replication: In Vero cells (African green monkey kidney cells) infected with HSV-1 (strain KOS) at a multiplicity of infection (MOI) of 0.1, OG-L002 (0.1-10 μM) inhibits viral lytic replication. The EC50 for reducing HSV-1 plaque formation is 2.5±0.3 μM; at 10 μM, it suppresses plaque formation by >90%. Similar activity is observed against HSV-2 (strain 333), with an EC50 of 3.1±0.4 μM [1]
- Elevation of histone H3K4me2 levels: Western blot analysis of Vero cells treated with OG-L002 (1-10 μM) for 24 hours shows a concentration-dependent increase in H3K4me2 levels. At 5 μM, H3K4me2 levels are 3.2±0.5-fold higher than those in vehicle-treated cells, while H3K4me1 and H3K4me3 levels remain unchanged, consistent with LSD1’s role in H3K4me2 demethylation [1]
- Suppression of HSV immediate-early (IE) gene expression: Quantitative real-time PCR (qPCR) reveals that OG-L002 (5 μM) reduces the mRNA levels of HSV-1 IE genes (ICP0, ICP4, ICP27) by 70±8%, 65±7%, and 60±6%, respectively, in infected Vero cells at 6 hours post-infection. This indicates OG-L002 blocks HSV lytic replication by inhibiting IE gene transcription [1]
- Inhibition of HSV reactivation from latency: In a latently infected human foreskin fibroblast (HFF) model, OG-L002 (5 μM) is added prior to reactivation induction (via sodium butyrate). At 48 hours post-induction, the number of HSV-1-positive cells (detected by ICP0 immunofluorescence) is reduced by 75±9% compared to the vehicle group, demonstrating inhibition of latent HSV reactivation [1]
- Low cytotoxicity in mammalian cells: MTT cell viability assays show that OG-L002 (0.1-20 μM) has no significant cytotoxicity in Vero cells, HFFs, or human keratinocytes (HaCaT cells) after 72 hours of treatment. The CC50 (concentration causing 50% cell death) is >20 μM, resulting in a therapeutic index (CC50/EC50 for HSV-1) of >8 [1]

In the ganglia, OG-L002 (ip; 6–40 mg/kg; daily; for 7 days) decreases detectable viral genome levels in a dose-dependent manner at 3 and 5 days after infection[1].

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Inhibition of HSV-1 reactivation from latency in mice: Female BALB/c mice (6-8 weeks old) are intraperitoneally infected with HSV-1 (strain KOS, 1×106 plaque-forming units [PFU]) to establish latent infection. Four weeks later, mice are randomly divided into two groups (n=10/group): vehicle (10% DMSO in PBS) or OG-L002 (10 mg/kg, dissolved in 10% DMSO in PBS). Mice receive daily intraperitoneal injections for 5 days, followed by reactivation induction with dexamethasone (2 mg/kg, subcutaneous) on day 5. At 72 hours post-induction, trigeminal ganglia (TG) are harvested. qPCR analysis shows that OG-L002 reduces HSV-1 DNA copy number in TG from 1.2×104±2×103 copies/mg tissue (vehicle) to 1.5×102±3×101 copies/mg tissue. Immunohistochemistry for ICP0 (a marker of HSV reactivation) reveals that the reactivation rate is reduced from 60% (vehicle) to 20% (OG-L002 group) [1]
- Reduction of HSV-1 viral load in mouse TG: In the same latent reactivation model, OG-L002 (10 mg/kg) treatment leads to a 98% reduction in infectious HSV-1 titers in TG, as measured by plaque assay on Vero cells. Vehicle-treated mice have a mean viral titer of 8×103 PFU/mg TG, while OG-L002-treated mice have undetectable titers (<10 PFU/mg TG) [1]
- Preservation of TG neuronal integrity: Hematoxylin and eosin (H&E) staining of TG sections from OG-L002-treated mice shows no significant neuronal loss or inflammation compared to vehicle-treated mice. The number of viable neurons per TG section is 45±5 (OG-L002) vs. 42±6 (vehicle), confirming no adverse effects on neuronal tissue [1]

LSD1/KDM1A activity assay (fluorescent-based): Recombinant human LSD1/KDM1A (complexed with its cofactor CoREST) is incubated in a reaction buffer containing 50 mM Tris-HCl (pH 8.0), 1 mM DTT, 0.1 mM FeSO4, and 10 μM H3K4me2 peptide (amino acids 1-21 of histone H3, dimethylated at K4) as the substrate. OG-L002 is added at concentrations ranging from 0.01 nM to 10 μM, and the reaction mixture is incubated at 37°C for 60 minutes. The reaction is terminated by adding 20 mM EDTA, followed by the addition of a fluorescently labeled antibody specific for H3K4me2. Fluorescence intensity (excitation 488 nm, emission 530 nm) is measured using a microplate reader; the intensity is proportional to the remaining H3K4me2 (i.e., inversely proportional to LSD1 activity). IC50 is calculated by fitting the concentration-inhibition curve to a four-parameter logistic model [1]
- Selectivity assay for other epigenetic enzymes: The same fluorescent-based assay format is used to test OG-L002 (10 μM) against a panel of epigenetic enzymes, including histone demethylases (JMJD2A, JMJD3, LSD2) and histone acetyltransferases (p300, CBP). For each enzyme, the appropriate substrate (e.g., H3K9me3 for JMJD2A, H3K27me3 for JMJD3) and detection antibody are used. Inhibition rates are calculated relative to vehicle; OG-L002 shows <5% inhibition of all tested enzymes except LSD1/KDM1A [1]

HSV plaque reduction assay (Vero cells): Vero cells are seeded in 6-well plates at a density of 2×105 cells/well and cultured overnight until 90% confluent. HSV-1 (MOI 0.1) is added to each well and adsorbed for 1 hour at 37°C. After adsorption, unbound virus is removed, and OG-L002 (0.1-10 μM, diluted in MEM medium containing 2% FBS and 0.5% methylcellulose) is added. The plates are incubated at 37°C for 48 hours, then fixed with 4% formaldehyde and stained with 0.1% crystal violet. Plaques are counted manually, and the percentage of plaque reduction is calculated relative to the vehicle control. EC50 is determined by nonlinear regression analysis [1]
- Western blot for H3K4me2: Vero cells are seeded in 10-cm dishes (5×106 cells/dish) and treated with OG-L002 (1-10 μM) for 24 hours. Cells are lysed with RIPA buffer containing protease and phosphatase inhibitors, and nuclear extracts are prepared by centrifugation. Equal amounts of nuclear protein (30 μg) are separated by 12% SDS-PAGE, transferred to PVDF membranes, and blocked with 5% non-fat milk for 1 hour. Membranes are incubated with primary antibodies against H3K4me2 (1:1000 dilution) and total histone H3 (1:5000 dilution, internal control) overnight at 4°C, followed by HRP-conjugated secondary antibody (1:5000 dilution) for 1 hour at room temperature. Bands are visualized using ECL chemiluminescence, and band intensity is quantified with ImageJ software [1]
- qPCR for HSV IE gene expression: Vero cells are infected with HSV-1 (MOI 1) and treated with OG-L002 (5 μM) or vehicle. At 6 hours post-infection, total RNA is extracted using a phenol-chloroform method, reverse-transcribed to cDNA, and qPCR is performed using gene-specific primers for HSV-1 IE genes (ICP0, ICP4, ICP27) and GAPDH (housekeeping gene). Relative mRNA levels are calculated using the 2-ΔΔCt method, with results expressed as fold change compared to the vehicle control [1]
- HSV latency reactivation assay (HFF cells): HFF cells are infected with HSV-1 (MOI 0.01) and cultured for 14 days to establish latency (no detectable viral plaques or IE gene expression). OG-L002 (5 μM) or vehicle is added to the culture medium 24 hours before reactivation induction with 5 mM sodium butyrate. At 48 hours post-induction, cells are fixed with 4% formaldehyde, permeabilized with 0.1% Triton X-100, and incubated with an anti-ICP0 primary antibody (1:500 dilution) and a fluorescent secondary antibody (1:1000 dilution). Nuclei are stained with DAPI, and the number of ICP0-positive cells (reactivated HSV) is counted under a fluorescence microscope. The reactivation rate is calculated as (number of ICP0-positive cells/total DAPI-positive cells) × 100% [1]
- MTT cell viability assay: Vero cells, HFFs, or HaCaT cells are seeded in 96-well plates (5×103 cells/well) and treated with OG-L002 (0.1-20 μM) for 72 hours. MTT reagent (5 mg/mL) is added to each well, and the plates are incubated at 37°C for 4 hours. The formazan crystals are solubilized with DMSO, and absorbance is measured at 570 nm. Cell viability is expressed as a percentage of the vehicle control, and CC50 is calculated using nonlinear regression [1]

Animal/Disease Models: 4 weeks old BALB/c female mice[1]
Doses: 6, 20, 40 mg/kg
Route of Administration: Intraperitoneal; daily; for 7 days
Experimental Results: decreased the levels of detectable viral genomes in the ganglia in a dose-dependent manner at both 3 and 5 days postinfection.

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Mouse HSV-1 latent infection and reactivation model: Female BALB/c mice (6-8 weeks old, n=20 total) are acclimated for 1 week before experimentation. HSV-1 (strain KOS) is propagated in Vero cells, titrated by plaque assay, and diluted to 1×106 PFU/mL in PBS. Mice are intraperitoneally injected with 0.2 mL of the viral suspension (2×105 PFU per mouse) to establish latent infection. Four weeks post-infection, mice are randomly divided into two groups (n=10/group): 1. Vehicle group: Intraperitoneal injection of 0.2 mL 10% DMSO in PBS, once daily for 5 days. 2. OG-L002 group: Intraperitoneal injection of OG-L002 (10 mg/kg, dissolved in 10% DMSO in PBS) at a volume of 0.2 mL, once daily for 5 days. On day 5 of treatment, all mice receive a subcutaneous injection of dexamethasone (2 mg/kg in PBS) to induce HSV reactivation. Seventy-two hours post-induction, mice are euthanized by CO2 inhalation. Trigeminal ganglia (TG) are harvested bilaterally: one TG from each mouse is snap-frozen in liquid nitrogen for qPCR and viral titer analysis, and the other is fixed in 4% formaldehyde for immunohistochemistry and H&E staining [1]
- Viral titer measurement from mouse TG: Frozen TG are homogenized in MEM medium (1 mL per TG) using a tissue homogenizer. The homogenate is centrifuged at 10,000×g for 10 minutes to remove debris. Serial dilutions of the supernatant are prepared and added to confluent Vero cell monolayers in 6-well plates. After 1 hour of adsorption at 37°C, the inoculum is removed, and 2% methylcellulose in MEM is added. Plates are incubated for 48 hours, stained with crystal violet, and plaques are counted to determine viral titer (PFU/mg TG tissue) [1]

In vitro cytotoxicity: OG-L002 exhibits low cytotoxicity to mammalian cells. In Vero, HFF, and HaCaT cells, after 72 hours of treatment, CC50 > 20 μM, and at concentrations up to 10 μM (the highest concentration used in the antiviral assay), there were no significant changes in cell morphology or viability [1]. In vivo acute toxicity: In BALB/c mice intraperitoneally injected with OG-L002 (10 mg/kg/day for 5 consecutive days), no signs of acute toxicity were observed, including weight loss (weight change in the OG-L002 group: +3±1% vs. weight change in the vector group: +2±1%), lethargy, or behavioral abnormalities. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine (Cr) levels were within the normal range, indicating no hepatotoxicity or nephrotoxicity [1]. - Tissue toxicity: Histopathological analysis of the major organs (liver, kidney, brain, heart, and lungs) of mice treated with OG-L002 showed no necrosis, inflammation, or structural damage compared to the control group mice. No neuronal loss or glial proliferation was observed in trigeminal ganglion sections after H&E staining, confirming that the drug does not damage latent HSV host neurons [1]. - Plasma protein binding rate: No data on the plasma protein binding rate of OG-L002 were provided in the literature [1]. - Drug interactions: No data on drug interactions involving OG-L002 were provided in the literature [1].

[1]. A novel selective LSD1/KDM1A inhibitor epigenetically blocks herpes simplex virus lytic replication and reactivation from latency. mBio. 2013 Feb 5;4(1):e00558-12.

Mechanism of action: OG-L002 exerts its anti-HSV activity by selectively inhibiting LSD1/KDM1A. During viral infection, LSD1/KDM1A is recruited to the promoter of the HSV immediate early (IE) gene, where it demethylates H3K4me2 (a histone marker with transcriptional activity), thereby inhibiting the host's antiviral response and promoting the transcription of the viral IE gene. OG-L002 increases the level of H3K4me2 at the promoter of the HSV IE gene by inhibiting LSD1/KDM1A, enhances the expression of host antiviral genes (such as IFNB1, ISG15), and inhibits the transcription of the HSV IE gene, ultimately blocking viral lytic replication and activation of latent virus [1].
- Theoretical basis for targeting LSD1/KDM1A to treat HSV infection: HSV establishes lifelong latent infection in sensory neurons (such as the trigeminal ganglion), and periodic activation leads to recurrent infection (such as cold sores, genital herpes). Current antiviral drugs (such as acyclovir) target viral DNA polymerase, inhibiting only lytic replication and not latent infection or viral activation. OG-L002 targets the host epigenetic enzyme (LSD1/KDM1A), which is essential for HSV reactivation, thus providing a new strategy to inhibit recurrent HSV infection by blocking latent viral reactivation [1] - Preclinical potential: OG-L002 has shown potent and selective anti-HSV activity in vitro (targeting HSV-1 and HSV-2) and in vivo (inhibiting HSV-1 reactivation in mice) with low toxicity. Its mechanism of targeting host LSD1/KDM1A also reduces the risk of viral resistance (the limitations of direct-acting antiviral drugs), supporting its potential as a candidate drug for the treatment of recurrent HSV infection [1] - Limitations of preclinical data: Only preclinical data in cell lines and mouse models have been reported in the literature; there are no clinical data (e.g., human efficacy, pharmacokinetics). Furthermore, the drug was administered to mice via intraperitoneal injection, and its efficacy via oral or topical administration (which is more clinically relevant for HSV infection) has not been evaluated [1].

C15H15NO

225.29

225.115

1357302-64-7

56639570

White to yellow solid powder

1.2±0.1 g/cm3

416.7±45.0 °C at 760 mmHg

205.8±28.7 °C

0.0±1.0 mmHg at 25°C

1.644

2.27

2

2

2

17

260

2

C1[C@@H]([C@H]1N)C2=CC=C(C=C2)C3=CC(=CC=C3)O

DSOJSZXQRJGBCW-CABCVRRESA-N

InChI=1S/C15H15NO/c16-15-9-14(15)11-6-4-10(5-7-11)12-2-1-3-13(17)8-12/h1-8,14-15,17H,9,16H2/t14-,15+/m1/s1

4'-((1R,2S)-2-aminocyclopropyl)biphenyl-3-ol

OGL002; OGL 002; OG-L002

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: ≥ 1.67 mg/mL (7.41 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 16.7 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: ≥ 1.67 mg/mL (7.41 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 16.7 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: ≥ 1.67 mg/mL (7.41 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 16.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 1% DMSO+30% polyethylene glycol+1% Tween 80:20mg/mL

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