Quercetin 3-O-glucuronide

Miquelianin (Quercetin 3-O-glucuronide) is a metabolite of quercetin and a type of natural flavonoid.

Miquelianin shows an antioxidant effect in human plasma. At 50 μM, miquelianin suppresses the consumption of the three antioxidants lycopene, β-carotene and α-tocopherol significantly[1]. In vitro studies indicate that miquelianin is able to reach the central nervous system from the small intestine[2]. Miquelianin significantly reduces the generation of β-amyloid (Aβ) peptides by primary neuron cultures generated from the Tg2576 AD mouse model. It is also capable of interfering with the initial protein-protein interaction of Aβ1–40 and Aβ1–42 that is necessary for the formation of neurotoxic oligomeric Aβ species[3]. Treatment with 0.1 μM miquelianin suppresses ROS generation, cAMP and RAS activation, phosphorylation of ERK1/2 and the expression of HMOX1, MMP2, and MMP9 genes. Miquelianin suppresses invasion of MDA-MB-231 breast cancer cells and MMP-9 induction, and inhibits the binding of [3H]-NA to b2-AR. Miquelianin may function to suppress invasion of breast cancer cells by controlling b2-adrenergic signaling, and may be a dietary chemopreventive factor for stress-related breast cancer[4].

Miquelianin treatment, compared to vehicle-control treatment, significantly improves AD-type deficits in hippocampal formation basal synaptic transmission and long-term potentiation[3]. A flavonoid fraction obtained from a crude extract of Hypericum perforatum (St. John's wort) is remarkably active in the forced swimming test. Miquelianin is one of the compound separated from the fraction[5].

References:
[1]. Terao J, e al. Protection by quercetin and quercetin 3-O-beta-D-glucuronide of peroxynitrite-induced antioxidant consumption in human plasma low-density lipoprotein. Free Radic Res. 2001 Dec;35(6):925-31.
[2]. Juergenliemk G, et al. In vitro studies indicate that miquelianin (quercetin 3-O-beta-D-glucuronopyranoside) is able to reach the CNS from the small intestine. Planta Med. 2003 Nov;69(11):1013-7.
[3]. Butterweck V, et al. Flavonoids from Hypericum perforatum show antidepressant activity in the forced swimming test. Planta Med. 2000 Feb;66(1):3-6.
[4]. Yamazaki S, et al. Quercetin-3-O-glucuronide inhibits noradrenaline-promoted invasion of MDA-MB-231 human breast cancer cells by blocking β -adrenergic signaling. Arch Biochem Biophys. 2014 Sep 1;557:18-27.
[5]. Ho L, et al. Identification of brain-targeted bioactive dietary quercetin-3-O-glucuronide as a novel intervention for Alzheimer's disease. FASEB J. 2013 Feb;27(2):769-81.