Orally administrated rare earth element cerium induces metallothionein synthesis and increases glutathione in the mouse liver.

Abstract The influence of oral administration of rare earth element cerium (Ce) was studied in relation to metallothionein (MT) and glutathione (GSH) content in the organs of ICR mice, which were administered heavy metal cadmium (Cd) for comparison. Male ICR mice were divided into 9 groups: 1 control group, 4 cerium groups and 4 cadmium groups, each with 4 mice, for a total of 36 mice. Ce groups included a 20 ppm CeCl 3 diet (Ce-low) group and a 200 ppm CeCl 3 diet (Ce-high) group, as did Cd groups, i.e., a 20 ppm CdCl 2 diet (Cd-low) group and a 200 ppm CdCl 2 diet (Cd-high) group. Each group was subdivided in 2 groups except a control group: 6-week administration group and 12-week administration group. The level of plasma aspartate aminotransferase(AST) activity, plasma alanine aminotransferase(ALT) activity, plasma cholesterol and plasma triglyceride in the Ce-low, Cd-low, Ce-high, and Cd-high group were higher than that of control group, although there were no significant differences ( p > 0.05). By contrast, both Ce and Cd groups had higher levels of MT and GSH in hepatic cells compared to the control group ( p p p p > 0.05). In conclusion, it is suggested that orally administered Ce increases MT and GSH as an antioxidant in the mouse liver, and these reaction are probably caused by increases in the oxidative stress with Ce.