Comparison of toxicity between lanthanum oxide nanoparticles and lanthanum chloride

Due to the wide application of rare earth elements, lanthanum (La) is gradually accumulated in our living environment. Lanthanum can enter the body through a variety of routes, which has a series of effects on various systems. As a consequence, the safety of lanthanum deserves our attention. This study aims to compare the toxicity of lanthanum oxide nanoparticles (La2O3 NPs) and lanthanum chloride (LaCl3) and enrich the toxicity evaluation of lanthanum. Therefore, a 30 d intragastal experiment was conducted. C57BL/6j mice were given by La2O3 NPs solution and LaCl3 solution respectively at doses of 0, 30, 60 and 120 mg/kg BW (lanthanum content). The results show that, compared with the control group, both La2O3 NPs and LaCl3 can reduce the body weight of female mice in the high-dose group, but for male mice, the high-dose La2O3 NPs solution can increase the body weight, while LaCl3 has the opposite effect. The coefficients of liver, kidney, heart, lung, uterine and ovaries increase first and then decrease with the exposure dose, but testes and epididymides coefficient keep increasing with the exposure of LaCl3 and La2O3 NPs. La2O3 NPs and LaCl3 can reduce the concentration of triglycerides (TG) and increase the level of low density lipoprotein (LDL), but the effect of La2O3 NPs is more obvious. La2O3 NPs and LaCl3 can reduce the concentration of malondialdehyde (MDA), increase the total antioxidant capacity (T–AOC) and enhance the activity of catalase (CAT), but LaCl3 has more obvious protective effects on oxidative stress. La2O3 NPs and LaCl3 have potential risks to liver, and the toxicity of La2O3 NPs might be higher than that of LaCl3.