Abstract:

The intent of this research was to explore the effect of metallothioneins from yeast with self-owned intellectual
property rights on protecting against oxidative damage and expelling mercury in mice with chronic mercury poisoning. The
mice with mercuric chloride exposure were continuously lavaged with two types (MT-1 and MT-2) of metallothioneins
from yeast and dimercaptopropansulfonate sodium (DMPS) for 28 days, respectively. Body weight, mercury level in the
whole blood, SOD, GSH-Px and MDA levels in serum, and total antioxidative capacity (T-AOC) in the body were measured
at the end of the administration period. Compared with the normal control group, body weight in the model control group
significantly decreased (P < 0.05), while both high-dose MT treatment groups showed a significant increase in body weight
after gavaging for 28 days (P < 0.05). The mercury levels in blood, liver and kidney in all drug treatment groups were decreased
significantly when compared with the model control group (P < 0.05). The effects of two types of high-dose metallothioneins on
expelling mercury were significantly better than that of DMPS (P < 0.05). SOD, GSH-Px, MDA levels in serum and T-AOC in the
body in all administration groups were brought back to the levels of the normal group (P > 0.05). Two monomeric forms of MT
at the high dose had significant impact on improving total antioxidant capacity in the body better than that of DMPS (P < 0.05).
However, MT-1 was significantly superior to MT-2 in increasing serum SOD and reducing serum MDA. Both metallothioneins
from yeast had an obvious effect on expelling mercury and protecting against oxidative damage.

Key words: metallothioneins from yeast, mercury, oxidative damage, protection