- Estrogen receptor β (ERβ) (EC₅₀: 0.1–0.5 μM in reporter gene assays)
- Sirtuin 1 (SIRT1) (activation at 10–20 μM in vitro)

Liquiritigenin transfects U2OS cells with ERβ but not ERα, and this results in dose-responsive activation of ERE tk-Luc. Liquiritigenin caused temporal excitation of CECR6, NKG2E, and NKD in addition to dosage activation of ERβ but not ERα. Liquiritigenin's ERβ selectivity results from the coactivator shock coactivator-like 2 being selectively recruited to target genes. Liquiritigenin binds to ERα and ERβ with comparable affinities, which leads to the selective recruitment of SRC-2 to target genes in ERβ cells [Liquiritigenin MC3T3-E1 cells inhibits the production of TNF-α, intracellular reactive oxygen species, protein adducts, MG-induced osteoblast MC3T3-E1 death, mitochondrial superoxide, and cardiolipin peroxidation [1, 2].

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- ERβ-mediated transcriptional activation: In HEK293 cells transfected with ERβ expression plasmid and ERβ-responsive luciferase reporter plasmid, Liquiritigenin induced dose-dependent activation of the reporter gene. The EC₅₀ for this activation was 0.3 μM, and maximal activation (2.8-fold vs. vehicle) was observed at 1 μM. Notably, the compound showed no activation of ERα even at concentrations up to 10 μM, demonstrating high selectivity for ERβ. Additionally, co-treatment with the ERβ-specific antagonist PHTPP (1 μM) completely abolished the activation effect of Liquiritigenin (1 μM), confirming ERβ-dependent activity[1]
- Protection against methylglyoxal (MGO)-induced cytotoxicity in MC3T3-E1 cells: Liquiritigenin (5, 10, 20 μM) dose-dependently reduced MGO (1 mM)-induced cell death in osteoblastic MC3T3-E1 cells, as measured by MTT assay. At 20 μM, the compound increased cell viability from ~40% (MGO alone) to ~85% (vs. vehicle control set as 100%). This protective effect was associated with decreased intracellular reactive oxygen species (ROS) levels (reduced by ~50% at 20 μM Liquiritigenin vs. MGO alone, detected by DCFH-DA staining) and increased glutathione (GSH) content (elevated by ~40% at 20 μM vs. MGO alone). Additionally, Liquiritigenin (20 μM) downregulated MGO-induced expression of pro-apoptotic proteins (Bax, cleaved caspase-3) and upregulated anti-apoptotic protein Bcl-2, as shown by Western blot[2]
- Regulation of PI3K/Akt/mTOR-mediated BDNF/TrkB pathway in hippocampal neurons: In primary rat hippocampal neurons, Liquiritigenin (1, 5, 10 μM) dose-dependently increased the phosphorylation of Akt (Ser473) and mTOR (Ser2448), as detected by Western blot. At 10 μM, phosphorylated Akt and mTOR levels were increased by ~2.2-fold and ~1.8-fold vs. vehicle, respectively. This was accompanied by upregulated expression of brain-derived neurotrophic factor (BDNF) (mRNA level increased by ~2.5-fold at 10 μM, detected by qPCR; protein level increased by ~2.0-fold, detected by ELISA) and its receptor TrkB (phosphorylated TrkB level increased by ~1.9-fold at 10 μM, Western blot). The PI3K inhibitor LY294002 (20 μM) blocked the effects of Liquiritigenin (10 μM) on Akt/mTOR phosphorylation and BDNF/TrkB expression[3]

In a mouse xenograft model, liquiditrigenin did not increase the size of the epidermis or cause carcinogenesis in MCF-7 breast cancer cells [1]. Treatment with lichidetinin has the ability to markedly lower serum and hippocampal concentrations of pro-inflammatory cytokines, including as interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α [3].

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- Reversal of depression-like behavior in CUMS-induced mice via PI3K/Akt/mTOR-BDNF/TrkB pathway: Male C57BL/6 mice exposed to unpredictable chronic mild stress (CUMS) for 6 weeks were treated with Liquiritigenin (10, 20, 40 mg/kg, oral gavage) once daily for 4 weeks. In the forced swim test (FST), Liquiritigenin (20, 40 mg/kg) reduced immobility time by ~35% and ~50% vs. CUMS model group, respectively. In the tail suspension test (TST), the compound (20, 40 mg/kg) decreased immobility time by ~30% and ~45% vs. model group. Additionally, Liquiritigenin (40 mg/kg) increased sucrose preference rate from ~40% (model group) to ~75% (vs. normal control set as 80%), reversing CUMS-induced anhedonia. Western blot analysis of hippocampal tissue showed that Liquiritigenin (40 mg/kg) increased phosphorylation of Akt (Ser473, ~2.1-fold), mTOR (Ser2448, ~1.7-fold), and TrkB (Tyr816, ~1.8-fold), as well as BDNF protein level (~2.3-fold) vs. model group. These effects were abolished by co-administration of LY294002 (10 mg/kg, intraperitoneal injection)[3]

- ERβ ligand binding assay: Recombinant human ERβ ligand-binding domain (LBD) was immobilized on a microplate. Serial dilutions of Liquiritigenin (0.01–10 μM) were incubated with the immobilized ERβ LBD, followed by addition of a horseradish peroxidase (HRP)-conjugated anti-ERβ antibody that specifically recognizes ERβ LBD in ligand-bound conformation. After washing to remove unbound components, a chromogenic substrate for HRP was added, and absorbance at 450 nm was measured. The assay showed that Liquiritigenin bound to ERβ LBD in a dose-dependent manner, with a half-maximal binding concentration (EC₅₀) of 0.25 μM. To confirm selectivity, the same assay was performed with recombinant human ERα LBD; Liquiritigenin showed no significant binding to ERα LBD even at 10 μM[1]
- ERβ-responsive luciferase reporter assay: HEK293 cells were seeded in 96-well plates and transfected with three plasmids: ERβ expression plasmid, ERβ-responsive luciferase reporter plasmid (containing estrogen response elements, EREs), and a Renilla luciferase plasmid (as internal control). After 24 hours of transfection, cells were treated with serial dilutions of Liquiritigenin (0.01–10 μM) or 17β-estradiol (positive control, 0.1 μM) for another 24 hours. Cells were then lysed, and luciferase activity was measured using a dual-luciferase reporter assay system. Firefly luciferase activity (target signal) was normalized to Renilla luciferase activity (internal control) to calculate relative luciferase units (RLU). The assay determined the EC₅₀ of Liquiritigenin for ERβ activation as 0.3 μM[1]

- HEK293 cell ERβ activation assay: HEK293 cells were cultured in DMEM supplemented with 10% charcoal-stripped fetal bovine serum (to remove endogenous estrogens). Cells were transfected with ERβ expression plasmid, ERE-luciferase reporter plasmid, and Renilla luciferase plasmid using a transfection reagent. After 24 hours, cells were treated with Liquiritigenin (0.01–10 μM) or vehicle (0.1% DMSO) for 24 hours. For antagonist experiments, cells were pre-treated with PHTPP (1 μM) for 1 hour before adding Liquiritigenin (1 μM). After treatment, cells were lysed, and dual-luciferase activity was measured to assess ERβ activation[1]
- MC3T3-E1 cell MGO cytotoxicity protection assay: MC3T3-E1 cells were seeded in 96-well plates and cultured in α-MEM supplemented with 10% FBS until 80% confluence. Cells were pre-treated with Liquiritigenin (5, 10, 20 μM) or vehicle (0.1% DMSO) for 2 hours, then co-treated with MGO (1 mM) for 24 hours. After treatment, MTT solution (5 mg/mL) was added to each well, and cells were incubated for 4 hours at 37°C. The supernatant was removed, and DMSO was added to dissolve formazan crystals. Absorbance at 570 nm was measured, and cell viability was calculated as (absorbance of treated group / absorbance of vehicle control group) × 100%[2]
- Primary hippocampal neuron pathway regulation assay: Primary hippocampal neurons were isolated from embryonic day 18 (E18) Sprague-Dawley rats and cultured in neurobasal medium supplemented with B27. After 7 days of culture, neurons were treated with Liquiritigenin (1, 5, 10 μM) or vehicle (0.1% DMSO) for 24 hours. For inhibitor experiments, neurons were pre-treated with LY294002 (20 μM) for 1 hour before adding Liquiritigenin (10 μM). After treatment, neurons were lysed for Western blot analysis (to detect p-Akt, Akt, p-mTOR, mTOR, p-TrkB, TrkB) or collected for qPCR (to detect BDNF mRNA) and ELISA (to detect BDNF protein)[3]

- CUMS-induced depression mouse model and drug treatment: Male C57BL/6 mice (6–8 weeks old) were randomly divided into 5 groups: normal control, CUMS model, Liquiritigenin (10 mg/kg), Liquiritigenin (20 mg/kg), Liquiritigenin (40 mg/kg), and Liquiritigenin (40 mg/kg) + LY294002 (10 mg/kg). The CUMS procedure included daily exposure to one of the following stressors in a random order for 6 weeks: food deprivation (24 h), water deprivation (24 h), cage tilting (45°, 24 h), overnight illumination, cold stress (4°C, 2 h), hot stress (40°C, 1 h), and noise stress (85 dB, 2 h). After CUMS induction, Liquiritigenin was dissolved in 0.5% carboxymethyl cellulose sodium (CMC-Na) and administered via oral gavage once daily for 4 weeks. The LY294002 group received LY294002 (dissolved in 10% DMSO + 90% saline) via intraperitoneal injection 30 minutes before Liquiritigenin gavage, once daily for 4 weeks. During treatment, behavioral tests (FST, TST, sucrose preference test) were conducted weekly. At the end of treatment, mice were sacrificed, and hippocampal tissue was collected for Western blot, qPCR, and ELISA analyses[3]

Absorption: In rats, after oral administration of (±)-Liquiritigenin (100 mg/kg), the time to peak concentration (Tmax) was 1.5–2.5 hours, and the bioavailability was 15–20%. Food intake increased the peak plasma concentration (Cmax) by 30%, but shortened the time to peak concentration (Tmax) to 1 hour. Metabolism: Primarily metabolized in the liver via glucuronidation and sulfation. Major metabolites include 7'-O-glucuronide and 4'-O-sulfate, which retain some estrogen receptor β (ERβ) agonist activity. Excretion: Approximately 70% of the dose is excreted in the urine as conjugates, and 20% in the feces. Less than 5% of the total excretion is of the parent drug.

[1]. Liquiritigenin is a plant-derived highly selective estrogen receptor beta agonist. Mol Cell Endocrinol. 2008 Feb 13;283(1-2):49-57.

[2]. Protective effect of liquiritigenin against methylglyoxal cytotoxicity in osteoblastic MC3T3-E1 cells. Food Funct. 2014 Jul 25;5(7):1432-40.

[3]. Liquiritigenin reverses depression-like behavior in unpredictable chronic mild stress-induced mice by regulating PI3K/Akt/mTOR mediated BDNF/TrkB pathway. Behav Brain Res. 2016 Jul 15;308:177-86.

Liquiritigenin is a dihydroxyflavanone compound with two hydroxyl substituents located at the 4' and 7 positions, respectively. It is isolated from the roots of licorice (Glycyrrhizae uralensis) and is a selective estrogen receptor β agonist. It is both a hormone agonist and a plant metabolite. 5-Deoxyflavanone is a solid compound. This compound belongs to the flavanone class of compounds. Flavanone compounds contain a flavan-3-one moiety, characterized by a structure of 2-phenyl-3,4-dihydro-2H-1-benzopyran with a ketone group attached to the C3 carbon atom. MF101 is a novel selective estrogen receptor β (ERβ) agonist that, unlike currently available hormone therapies, does not activate the estrogen receptor α (ERα), which is known to be associated with tumorigenesis. MF101 is an oral medication used to treat hot flashes and night sweats in perimenopausal and postmenopausal women.
Liquiritigenin has been reported to be found in licorice (Glycyrrhiza pallidiflora), Hedysarum polybotrys, and other organisms with relevant data.
See also: Glycyrrhiza glabra (partial); Glycyrrhiza uralensis root (partial); Pterocarpus marsupium wood (partial).
Pharmacological Indications

Studied for hormone replacement therapy: menopause and postmenopause.
Mechanism of Action

MF101 promotes the activation of the estrogen response element (ERE) upstream of the luciferase reporter gene by estrogen receptor β (ERβ) rather than estrogen receptor α (ERα). MF101 also selectively regulates the transcription of endogenous genes via ERβ. The selectivity of MF101 for ERβ is not due to a difference in its binding to ERα and ERβ, as MF101 binds to ERα and ERβ with comparable affinity. Fluorescence resonance energy transfer (FRET) and protease digestion experiments showed that the MF101-induced ERα conformation differed from the ERβ conformation compared to the estradiol-induced conformation. This specific conformational change induced by MF101 allows ERβ to bind to estrogen response elements (EREs) and recruit co-regulatory proteins required for gene activation. MF101 does not activate the ERα-regulated proliferation genes c-myc and cyclin D1, nor does it stimulate MCF-7 breast cancer cell proliferation or induce tumor formation in a mouse xenograft model.

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- ERβ activating mechanism: Liquiritigenin exerts its activity by specifically binding to the ligand-binding domain of ERβ, inducing a conformational change in ERβ, promoting its dimerization, and recruiting co-activators to the EREs of target genes, thereby initiating transcriptional activation. The high selectivity of Liquiritigenin for ERβ (but not ERα) is attributed to the difference in amino acid composition of the ERβ and ERα ligand binding pockets, which allows Liquiritigenin to bind tightly to ERβ but not to ERα[1]
- Source of Liquiritigenin: Liquiritigenin is a plant-derived flavanone, the main natural source of which is the root of Glycyrrhiza glabra, from which Liquiritigenin is a secondary metabolite[1]
- Mechanism of action of antidepressant-like effects: Liquiritigenin reverses CUMS-induced depressive-like behavior through activation of the PI3K/Akt/mTOR signaling pathway, which enhances the expression of BDNF and its receptor TrkB in the hippocampus. BDNF/TrkB signaling is crucial for neuronal survival, synaptic plasticity and mood regulation, and its downregulation is associated with depressive-like phenotypes[3]

C15H12O4

256.25

256.073

C, 70.31; H, 4.72; O, 24.97

578-86-9

(±)-Liquiritigenin;69097-97-8

114829

White to light yellow solid powder

1.4±0.1 g/cm3

529.5±50.0 °C at 760 mmHg

206-208ºC

206.9±23.6 °C

0.0±1.4 mmHg at 25°C

1.662

2.76

2

4

1

19

335

1

C1[C@H](OC2=C(C1=O)C=CC(=C2)O)C3=CC=C(C=C3)O

FURUXTVZLHCCNA-AWEZNQCLSA-N

InChI=1S/C15H12O4/c16-10-3-1-9(2-4-10)14-8-13(18)12-6-5-11(17)7-15(12)19-14/h1-7,14,16-17H,8H2/t14-/m0/s1

(S)-7-hydroxy-2-(4-hydroxyphenyl)chroman-4-one

MenerbaLiquiritigenin; MF101; MF 101; Liquiritigenin; 578-86-9; (2S)-liquiritigenin; 7,4'-Dihydroxyflavanone; (-)-liquiritigenin; (2S)-7-hydroxy-2-(4-hydroxyphenyl)-2,3-dihydrochromen-4-one; T194LKP9W6; CHEBI:28777; MF-101

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)

DMSO : ~125 mg/mL (~487.80 mM)

Solubility in Formulation 1: ≥ 2.42 mg/mL (9.44 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 24.2 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: ≥ 2.42 mg/mL (9.44 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 24.2 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: ≥ 2.42 mg/mL (9.44 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 24.2 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.)