Protective effects of crude polysaccharide from Xinyang red tea against Lead toxicity

To investigate protective effects of polysaccharides from Xinyang red tea against lead toxicity of mice, 60 healthy rats were randomly divided into six groups: control group, lead-poisoning model group and EDTA group, low, middle and high dose groups treated with 100 mg/kg of EDTA,50mg/kg,100mg/kg and 200mg/kg tea polysaccharide, respectively every day. The contents of lead in blood, liver and kidney were determined and the activity of d-aminolevulinic acid dehydratase (ALAD) and the level of reactive oxygen species (ROS) in blood were measured. Furthermore superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malonaldehyde (MDA) in liver were detected to explore the possible mechanism. Compared with the lead-poisoning group, there was a obvious increasei¼ÂˆP<0.05i¼Â‰in the activities of blood ALAD, GSH-Px, SOD and CAT and reduction in blood ROS and liver MDA contenti¼ÂˆP<0.05i¼Â‰in EDTA and tea polysaccharide treated groups. Meanwhile the activities of blood ALAD and GSH-Px, SOD and CAT of liver in tea polysaccharides treated groups increased while blood ROS and liver MDA level decreased compared to the EDTA group. Increments in the activities of blood ALAD, liver GSH-Px, SOD and CAT and reduction in blood ROS and liver MDA level appeared with increasing tea polysaccharide dose. It was indicated that polysaccharides from Xinyang red tea could improve the activity of antioxidant enzymes and alleviate oxidative stress induced by lead exposure on rats