Isoliquiritigenin is an anti-tumor flavonoid from the root of Glycyrrhiza glabra, which inhibits aldose reductase with an IC50 of 320 nM.

Isoliquiritigenin may prevent diabetic complications through inhibiting rat lens aldose reductase with an IC50 of 320 nM and sorbitol accumulation in human red blood cells with an IC50 of 2.0 μM[1]. Isoliquiritigenin (100 μM) markedly inhibits the hypoxia-induced prolonged TPS and TR90 of cardiomyocytes. Isoliquiritigenin significantly triggers AMPK Thr172 phosphorylation as compared with vehicle group. Isoliquiritigenin treatment also induces extracellular signal-regulated kinase (ERK) signaling pathway in the cardiomyocytes. Isoliquiritigenin treatment significantly decreases the intracellular ROS levels of isolated cardiomyocytes during hypoxia/reoxygenation[3]. Isoliquiritigenin not only downregulates IL-6 expression but also significantly decreases levels of phosphorylated ERK and STAT3 and can inhibit phosphorylation levels of ERK and STAT3 induced by recombinant human IL-6, which are critical signaling proteins in IL-6 signaling regulation networks[4].

Isoliquiritigenin shows concentration-dependent inhibition of the tonic contraction of mouse jejunum induced by various types of stimulants such as CCh (1 mM), KCl (60 mM) and BaCl2 (0.3 mM) with IC50 values of 4.96±1.97 mM, 4.03±1.34 mM and 3.70±0.58 mM, respectively[2]. Isoliquiritigenin exhibits significant anti-tumor activity in MM xenograft models and synergistically enhances the anti-myeloma activity of adriamycin[4].

References:
[1]. Aida K, et al. Isoliquiritigenin: a new aldose reductase inhibitor from glycyrrhizae radix. Planta Med. 1990 Jun;56(3):254-8.
[2]. Sato Y, et al. Isoliquiritigenin, one of the antispasmodic principles of Glycyrrhiza ularensis roots, acts in the lower part of intestine. Biol Pharm Bull. 2007 Jan;30(1):145-9.
[3]. Zhang X. Natural antioxidant-isoliquiritigenin ameliorates contractile dysfunction of hypoxic cardiomyocytes via AMPK signaling pathway. Mediators Inflamm. 2013;2013:390890.
[4]. Chen X, et al. Isoliquiritigenin inhibits the growth of multiple myeloma via blocking IL-6 signaling. J Mol Med (Berl). 2012 Nov;90(11):1311-9.