Protective effects of fulvotomentosides on cadmium-induced hepatotoxicity

Fulvotomentosides (Ful) is the total saponins of Lonicera fulvotomentosa. In the present study, we examined the effects of Ful on cadmium (CdCl2)-induced acute liver injury in mice. Ful pretreatment (150 mg.kg-1, sc x 3 d) remarkably decreased CdCl2 (3.7 mg Cd.kg-1, iv)-induced liver damage as indicated by serum activities of alanine aminotransferase and sorbitol dehydrogenase. Distribution of Cd to 12 organs and hepatic subcellular fractions was determined 2 h after Cd challenge. Ful pretreatment did not produce a marked shift in the distribution of Cd to various organs, but markedly altered the hepatic subcellular distribution of Cd, with more Cd bound to metallothionein (MT) in the cytosol, less in the nuclear, mitochondrial, and microsomal fractions. Ful pretreatment produced a dose-dependent increase in hepatic MT as determined by the Cd.hemoglobin assay. In conclusion, Ful protected against Cd hepatotoxicity by inducing MT, which binds Cd in the cytosol and lowers the amount of Cd available to other critical organelles and proteins.