Quercetin protected isolated human erythrocytes against mancozeb-induced oxidative stress

Mancozeb is a fungicide belonging to the ethylene-bisdithiocarbamate group and is widely used in agriculture. The aim of this study was to examine the protective effect of quercetin (QRN) against oxidative stress induced by mancozeb in human erythrocytes. In order to verify this, 5 ml of venous blood was collected and the erythrocytes were separated and divided into equal parts. One part was incubated with different concentrations of mancozeb (0, 10, 30, 100 mu M) for 4 h at 37 degrees C. The other part was preincubated with QRN (40 and 80 mu M) for 30 min, followed by mancozeb (0, 10, 30, 100 mu M) incubation for 4 h. We found reduction in the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) along with elevated levels of lipid peroxide (LPO) in erythrocytes incubated with 30 and 100 pm of mancozeb. Pre-incubation with QRN (80 mu M) reversed oxidative stress induced by mancozeb (30 mu M) and inhibited LPO induced at 100 mu M by 64.36%. QRN also reduced the haemolytic effect on erythrocytes but could not prevent the induction of haemolysis by mancozeb. Therefore, these results suggest that QRN may play a role in preventing the oxidative stress induced by mancozeb in human erythrocytes.