QUERCETIN

Labile zinc, a tiny fraction of total intracellular zinc that is loosely bound to proteins and easily interchangeable, modulates the activity of numerous signaling and metabolic pathways. Dietary plant polyphenols such as the flavonoids quercetin (QCT) and epigallocatechin-gallate act as antioxidants and as signaling molecules. Remarkably, the activities of numerous enzymes that are targeted by polyphenols are dependent on zinc.

Impaired myocardial contractile function, one of the well-documented features of sepsis, contributes greatly to the high rate of mortality. Quercetin is widely accepted as a potential antioxidant and free radical scavenger. Epidemiologic studies have suggested that an increase in the intake of dietary Quercetin can reduce the risk of cardiac disease.

Oxidative stress and inflammation play important roles in the pathogenesis of cardiovascular disease (CVD). Oxidative stress-induced desialylation is considered to be a primary step in atherogenic modification, and therefore, the attenuation of oxidative stress and/or inflammatory reactions may ameliorate CVD. In this study, quercetin 7-O-sialic acid (QA) was synthesized aiming to put together the cardiovascular protective effect of quercetin and the recently reported anti-oxidant and anti-atherosclerosis functions of N-acetylneuraminic acid.

Flavonoids are integral components of various vegetation and in foods; consequently, they represent an inevitable part of the diet. Historical and epidemiological proof recommend that diet plans consisting of flavonoids such as quercetin have positive health benefits, especially on the heart. Flavonoids have been proven to be active against hypertension, inflammation, diabetes and vascular diseases.

Quercetin is the great representative of polyphenols, flavonoids subgroup, flavonols. Its main natural sources in foods are vegetables such as onions, the most studied quercetin containing foods, and broccoli; fruits (apples, berry crops, and grapes); some herbs; tea; and wine.

Quercetin, the main component of flavonoids, has a wide range of biological actions. Quercetin can be made into a variety of additives for practice, because of the stable chemical structure and water-soluble derivatives.

In vitro and some animal models have shown that quercetin, a polyphenol derived fromplants, has a wide range of biological actions including anti-carcinogenic, anti-inflammatory and antiviral activities; as well as attenuating lipid peroxidation, platelet aggregation and capillary permeability.

Quercetin, one of the most abundant of plant flavonoids, has been studied with a great deal of attention over the last several decades mainly for its properties in inflammation and allergy. In this study, we are reporting for the first time the in vivo immunostimulatory activity of quercetin in ovalbumin immunized Balb/c mice

Atopic dermatitis (AD) is an inflammatory skin disease. Over the past few decades, AD has become more prevalent worldwide. Quercetin, a naturally occurring polyphenol, shows antioxidant, antiinflammatory, and antiallergic activities.

Quercetin is hardly bioavailable and largely transformed to different metabolites. Although little is known about their biological activities, these metabolites are crucial for explanation of health benefits associated with quercetin dietary intake.

Acrylonitrile is a potent hepatotoxic, mutagen, and carcinogen. A role for free radical mediated lipid peroxidation in the toxicity of acrylonitrile has been suggested. The present study was designed to assess the hepatoprotective effect of quercetin against acrylonitrile-induced hepatotoxicity in rats.