Abstract: Objective: To investigate the effect of two yeast metallothioneins (MT-1 and MT-2) on mercury elimination and the repairing of liver damage and oxidative damage in mice with acute mercury chloride poisoning. Methods: A mouse model of acute mercury poisoning was established by subcutaneous injection of mercuric chloride in normal saline in the neck. The acute mercury poisoning mice were lavaged with each MT at different doses or DMPS for 14 continuous days. At the end of the treatment period, the body weight, liver coefficient, mercury levels in blood and liver, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) in serum, and liver alanine aminotransferase (ALT) and aspartate transaminase (AST) activities were measured. Results: Compared with the normal group, body weight in the model group was significantly decreased (P < 0.05), and liver coefficient was increased (P < 0.05); serum mercury levels were increased significantly (P < 0.05); SOD and serum GSH-Px activities and T-AOC were decreased significantly (P < 0.05); serum MDA level and liver ALT and AST activities were increased significantly (P < 0.05). Yeast MT at middle and high doses and the positive control dimercaptopropansulfonate sodium resulted in significantly higher body weight compared with the model group (P < 0.05), and exhibited no significant difference from the normal group (P > 0.05). The treatments resulted in significantly dose-dependently reduced liver coefficient in comparison with the model group (P < 0.05). For all treatment groups, Hg2+ levels in serum and liver, serum MDA level, and liver ALT and AST activities were decreased to different extents, and serum GSH-Px and SOD activities and T-AOC were increased to different extents. High-dose yeast metallothioneins had the best effect in the dose range of 0.16–0.80 mg/kg, and the effect was significantly different from that of other groups (P < 0.05). Conclusion: Both yeast MT could significantly dose-dependently bind free Hg2+ in mice with acute mercury chloride poisoning and repair liver damage and oxidative damage.

Key words: yeast metallothioneins, mercury elimination, repairing, liver, oxidative damage