Lead-induced oxidative damage in rats/mice: A meta-analysis

Lead (Pb) is ubiquitous in the environment and is an environmental genotoxic metal. Pb accumulation in the body could cause the oxidative stress. This meta-analysis aimed to perform a systematic evaluation of the extent of oxidative damage in rats/mice induced by lead. All relevant articles in English or Chinese were retrieved from Embase, PubMed, Web of Science, Medline, China National Knowledge Infrastructure, and Chinese Biological Medicine databases from their inception date until July 22, 2018. A total of 108 eligible articles were included in this study. The indicators of oxidative stress included malondialdehyde (MDA), glutathione disulfide (GSSG), reactive oxygen species (ROS), hydrogen peroxide (H2O2), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced glutathione (GSH), superoxide dismutase (SOD), and glutathione-s-transferase (GST). The meta-analysis showed that lead significantly increased oxidants levels, such as MDA, GSSG, ROS, and H2O2 (P < 0.05), and significantly reduced the level of antioxidants, such as CAT, GPx, GR, GSH, SOD, and GST (P < 0.05). The intraperitoneal mode was more effective than water drinking mode in reducing the levels of CAT, GPx, GSH, and SOD (P < 0.05). Other factors that influenced the overall oxidative stress, including species of animals, type of tissues, and intervention dosage and time, were comprehensively evaluated. The results of meta-analysis indicated that mice were more sensitive to lead than rats, and intraperitoneal mode was an effective intervention mean. High doses and long periods of lead treatment can cause serious oxidative damage. Moreover, testicular was more vulnerable to lead than other tissues. These results provided scientific evidence for preventing and treating lead toxicity.