Abstract: Purpose: To evaluate the effect of two metallothioneins from yeast (MT-1 and MT-2) with self-owned intellectual property right on mercury elimination and liver damage repair in mice with chronic mercury poisoning. Methods: A mouse model of chronic mercury poisoning was established by giving the mice free access to deionized water containing mercuric chloride, and then the mice were orally administered with MT or dimercaptopropansulfonate sodium (DMPS) for 28 days. Body weight, liver index, blood and liver mercury levels, blood physiological and biochemical indicators and liver function were measured after the last administration. Results: Compared with the model group, the body weights of mice administered with MT were increased, the liver indexes and blood mercury and liver mercury levels were decreased significantly (P < 0.05), and white blood cell (WBC), red blood cell (RBC), platelet (PLT) and hemoglobin (HGB) levels were restored to different extents in a dose-dependent manner. Compared with the model group, the levels of serum ALT and AST in mice administered with MT were decreased. Based on these findings together with pathological examination, we found that MT could repair damaged liver tissues of mice with chronic mercury poisoning, restore liver cell edema to normal morphology, and reduce intercellular inflammatory infiltration and the effect was dose-dependent. Conclusions: Both metallothioneins from yeast have good efficacy in eliminating mercury and repairing damaged liver tissues in mice with chronic mercury poisoning, and MT-1 was superior to MT-2 and DMPS.

Key words: metallothionein from yeast, mercury poisoning, mercury elimination, liver, repair effect