Published online Apr 10, 2016. doi: 10.5306/wjco.v7.i2.189
Peer-review started: July 14, 2015
First decision: September 17, 2015
Revised: October 19, 2015
Accepted: February 14, 2016
Article in press: February 16, 2016
Published online: April 10, 2016
Processing time: 284 Days and 0.6 Hours
This review was based on a literature search of PubMed and Scielo databases using the keywords “quercetin, rutin, isoquercitrin, isoquercitin (IQ), quercetin-3-glucoside, bioavailability, flavonols and favonoids, and cancer” and combinations of all the words. We collected relevant scientific publications from 1990 to 2015 about the absorption, bioavailability, chemoprevention activity, and treatment effects as well as the underlying anticancer mechanisms of isoquercitin. Flavonoids are a group of polyphenolic compounds widely distributed throughout the plant kingdom. The subclass of flavonols receives special attention owing to their health benefits. The main components of this class are quercetin, rutin, and IQ, which is a flavonoid and although mostly found as a glycoside, is an aglycone (lacks a glycoside side chain). This compound presents similar therapeutic profiles to quercetin but with superior bioavailability, resulting in increased efficacy compared to the aglycone form. IQ has therapeutic applications owing to its wide range of pharmacological effects including antioxidant, antiproliferative, anti-inflammatory, anti-hypertensive, and anti-diabetic. The protective effects of IQ in cancer may be due to actions on lipid peroxidation. In addition, the antitumor effect of IQ and its underlying mechanism are related to interactions with Wnt signaling pathway, mixed-lineage protein kinase 3, mitogen-activated protein kinase, apoptotic pathways, as well proinflammatory protein signaling. This review contributed to clarifying the mechanisms of absorption, metabolism, and actions of IQ and isoquercitrin in cancer.
Core tip: Flavonoids have gained a great deal of attention over the years, and their health benefits are the focus of the new research studies. This review contributed to clarifying the mechanisms of absorption and metabolism of isoquercitin, as well as emphasizing its chemopreventive and therapeutics effects in cancer. Overall, we presented a hypothesis of the underlying mechanisms of this biocompound in cancer.