Protective effect of quercetin and rutin on photosensitized lysis of human erythrocytes in the presence of hematoporphyrin

Protective action of hydroxyethyl rutosides on singlet oxygen-challenged cardiomyocytes

“…A bell-shaped dose-response curve for HR has also been described recently in experimental studies on the permeability of microvessels in the frog mesentery (Kendall et al, 1993), as well as in clinical trials in patients with chronic venous insufficiency (Diebschlag et al, 1994). Flavonols have been shown to bind to biomembranes (Sorata et al, 1984) especially to membrane proteins (Gryglewski et al, 1987) which may result in the prevention of destabilization of cellular membranes. To explain the bell-shaped dose-response relationship Kendall et al (1993) offered the hypothesis that HR bind at two different sites which give rise to opposite effects.…”

“…Flavonoids are naturally occurring polyphenolic substances with free radical scavenging activity (Sorata et al, 1984;Husein et al, 1987;Robak & Gryglewski, 1988). Recent data showed an inverse correlation between dietary flavonoid intake and mortality from coronary heart disease (Hertog et al, 1993).…”

Quercetin: A Versatile Flavonoid

“…Quercetin also chelates ions of transition metals such as iron which can initiate the formation of oxygen free radicals 46,47 . Direct inhibition of lipid peroxidation is another protective measures 48 .…”

Hepatoprotective Effect of Quercetin Pretreatment Against Paracetamol-Induced Liver Damage and Partial Hepatectomy in Rats

“…In addition, there is evidence that quercetin is effective for cancer treatment and that it provides protection against cardiovascular, renal, and liver disease 6 . Quercetin scavenges reactive oxygen species (ROS), inhibits xanthine oxidase as well as lipid peroxidation, in addition to scavenging and stabilizing iron 7 . The superoxide anion and the hydroxyl radical are involved in liver damage resulting from lipid peroxidation and interstitial matrix degradation 8 .…”