Antitumor effect of isoquercetin on tissue vasohibin expression and colon cancer vasculature.

Tumor cells trigger angiogenesis through the expression of angiogenic factors. Vasohibins (VASHs) are a family of peptides that regulate angiogenesis. Flavonoids have antiproliferative antitumor properties; however, few studies have highlighted their antiangiogenic potential. This study evaluated the flavonoid isoquercetin (Q3G) as an antitumor compound related to colon cancer vascularization and regulation of VASH1 and 2. Mice bearing xenogeneic colon cancer (n = 15) were divided into 3 groups: Q3G-treated (gavage, daily over a week), bevacizumab-treated (intraperitoneal, single dose), or untreated animals. Tumor growth, histological characteristics, blood vessel volume, and VASH1 and 2 expressions were analyzed. Q3G impaired tumor growth and vascularization, upregulated VASH1, and downregulated VASH2 in comparison to untreated animals. Mice treated with Q3G showed approximately 65% fewer blood vessels than untreated animals and 50% fewer blood vessels than mice treated with bevacizumab. Thus, we show that Q3G has antitumor activity, impairs vascularization, and differentially modulates VASH1 and 2 expressions in colon cancer.

Parada cardiorrespiratória após infarto agudo do miocárdio por vasoespasmo coronariano. Relato de caso e revisão da literatura / Cardiorespiratory arrest after acute myocardial infarction due to coronary vasospasm. Case report and literature review

A angina vasoespástica é uma causa incomum de parada cardíaca e arritmias ventriculares. No entanto, os sobreviventes dessas complicações têm um risco aumentado de recorrência, apesar da função ventricular normal e do tratamento médico otimizado. Descrevemos o caso de uma ex-tabagista de 50 anos que teve parada cardiorrespiratória secundária a vasoespasmo coronariano grave.

Vasospastic angina is an uncommon cause of cardiac arrest and ventricular arrhythmias. However, survivors of these complications are at an increased risk of recurrence, despite normal ventricular function and optimized medical therapy. We describe a case of a 50-year-old former smoker who developed cardiorespiratory arrest secondary to severe coronary vasospasm.

Review of anticancer mechanisms of isoquercitin.

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.