Isoliquiritigenin (Chalcone · Anti-inflammatory · NLRP3 Inhibitor)

Compound	Isoliquiritigenin
Chemical class	Polyphenol — Chalcone (2′,4′,4-Trihydroxychalcone)
CAS	961-29-5
Primary source	Glycyrrhiza glabra, G. uralensis (licorice root)
Key applications	Anti-inflammatory, smooth muscle relaxant, oestrogenic
Claim strength	Moderate
Typical form	Licorice root extract co-constituent; isolate from specialist suppliers
Buy from Herbuno	Licorice Root Extract Powder | Mulethi → DGL Licorice Extract Powder | Mulethi →

Name origin: Iso- indicates the open-chain chalcone form that is the biosynthetic precursor to liquiritigenin (the corresponding flavanone formed by chalcone isomerase). The name therefore literally reflects the isomeric relationship to liquiritigenin within the licorice biosynthetic pathway. Traditional use: Licorice root (Gan Cao, Yashtimadhu) preparations containing isoliquiritigenin have been used across TCM, Ayurveda, and European phytomedicine for gastric inflammation, smooth muscle spasm, respiratory congestion, and hormonal balance. Isoliquiritigenin is a key bioactive chalcone co-present alongside glycyrrhizin, liquiritin, and glabridin. Research trajectory: Isoliquiritigenin has attracted research for its potent anti-inflammatory mechanism (NF-κB/NLRP3), smooth muscle relaxant activity (relevant to airway and GI applications), and oestrogen receptor activity. It is also one of the more studied chalcones for antiproliferative mechanisms. Commercial source: Commercially available as a co-constituent of Glycyrrhiza root extracts; isolated isoliquiritigenin is available from specialist botanical suppliers. See sourcing options below.

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Evidence for Isoliquiritigenin Applications

Anti-inflammatory and NLRP3 inhibition: Isoliquiritigenin is a direct NLRP3 inflammasome inhibitor — blocking the assembly of the NLRP3/ASC/caspase-1 complex upstream of IL-1β and IL-18 release. This mechanism is distinct from most NF-κB inhibitors and is particularly relevant to inflammatory conditions driven by the inflammasome (gout, NAFLD, atherosclerosis). Animal models of liver injury, colitis, and arthritis confirm in vivo anti-inflammatory efficacy. Claim strength: Moderate.

Smooth muscle relaxation: Isoliquiritigenin relaxes airway and vascular smooth muscle by inhibiting phosphodiesterase (PDE) and activating K+ channels, producing bronchodilatory and vasodilatory effects. This mechanism underpins the traditional use of licorice for cough and respiratory congestion. Relevant for respiratory health and antispasmodic formulations. Claim strength: Moderate.

Oestrogenic and bone-protective activity: Isoliquiritigenin is an ERβ agonist with documented osteoblast-stimulating and osteoclast-inhibiting activity in cell and animal models. Weak but measurable direct oestrogenic activity is complemented by aromatase-modulating effects. Claim strength: Moderate.

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Dosage & Formulator Specification

No established human clinical dose for isolated isoliquiritigenin. Active concentrations in preclinical NLRP3 inhibition studies: 10–50 µM in cell assays; animal anti-inflammatory models typically use 20–100 mg/kg oral dose. For formulation contexts, licorice root extract at 300–600 mg/day (standardised to total flavonoids or glycyrrhizin content) delivers isoliquiritigenin as a co-constituent.

For DGL (deglycyrrhizinated licorice) formulations targeting GI smooth muscle or NLRP3 applications, isoliquiritigenin is retained post-deglycyrrhizination. DGL at 400–800 mg/day is a practical delivery vehicle. Isolated isoliquiritigenin is not routinely available at commercial supplement scale; enquire with specialist suppliers for research-grade quantities.

Isoliquiritigenin has low aqueous solubility (chalcone scaffold, logP ~2.8). Compatible with lipid-based delivery or cyclodextrin complexation. Sensitive to isomerisation to liquiritigenin under acidic conditions and heat — relevant for RTD beverage applications where pH and processing temperature must be managed to preserve the chalcone form.

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Frequently Asked Questions — Isoliquiritigenin

What is the relationship between isoliquiritigenin and liquiritigenin?
Isoliquiritigenin is the open-chain chalcone; liquiritigenin is the corresponding flavanone formed when the chalcone undergoes ring closure (catalysed by chalcone isomerase in the plant, or spontaneously under acidic conditions). Both are bioactive and co-present in licorice root, with slightly different receptor and enzyme interaction profiles.

Is isoliquiritigenin the NLRP3 inhibitor in licorice?
Isoliquiritigenin is identified as a direct NLRP3 inflammasome inhibitor in cell and animal studies, which distinguishes it from other licorice actives (glycyrrhizin acts on HMGB1; liquiritin acts on tyrosinase). The NLRP3 inhibition mechanism is mechanistically well-characterised for isoliquiritigenin specifically, making it the most interesting licorice chalcone for inflammatory disease formulation research.

Does isoliquiritigenin carry the same glycyrrhizin-related safety concerns as standard licorice?
No. Isoliquiritigenin is a flavonoid, not a triterpene saponin. The pseudoaldosteronism risk associated with licorice is specific to glycyrrhizin. DGL preparations that remove glycyrrhizin retain isoliquiritigenin and other flavonoids. Isolated isoliquiritigenin does not carry mineralocorticoid-related safety concerns.

Is isoliquiritigenin relevant for metabolic inflammation formulations?
Yes. NLRP3 inflammasome activation is a central mechanism in obesity-driven metabolic inflammation, NAFLD progression, and type 2 diabetes complications. Isoliquiritigenin’s direct NLRP3 inhibition provides a mechanistically relevant positioning for metabolic health formulations targeting inflammatory insulin resistance and hepatic inflammation.

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Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.

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