A Protective Effect of Chlorella Supplementation on Cadmium-induced Nephrotoxicity in the Rats

  • Hwang Yoo-Kyeong (Department of Biomedical Laboratory Science, Inje University) ;
  • Choi Hyun-Jin (Department of Biomedical Laboratory Science, Inje University) ;
  • Nan Meng (Department of Biomedical Laboratory Science, Inje University) ;
  • Yoo Jai-Du (Department of Clinical Pathology, Masan College) ;
  • Kim Yong-Ho (Department of Biomedical Laboratory Science, Inje University, Department of Biohealth Products Research Center, Inje University)
  • Published : 2006.03.01

Abstract

The uptake of cadmium in animals is mainly accumulated in and affected to the liver and kidney by binding with red blood cells and serum albumin. The process accounts for more than 50% of the total accumulated cadmium in the body. The kidneys may be damaged without regarding the pathway uptake of cadmium. In a group of rats on supplements of 1% chlorella and 40 ppm cadmium, the concentration of cadmium in urine greatly decreased by 66% compared to control group, and the total synthesis of metallothionein decreased by 48.6% compared to control group. However, no previous study has assessed the protective effect on kidney damage induced by cadmium uptake through supplementation with chlorella. This study analyzed the biochemical marker for kidney damage in the rats after uptake of 40 ppm $CdCl_2$ and supplementation of the diet of Sprague Dawley (SD) rats with 1%, 5%, and 10% chlorella during 4 weeks. In a group of SD rats on supplementation with 1% chlorella and uptake of 40 ppm $CdCl_2,\;\beta_2$ microglobulin in the urine was found to be $3.1\pm0.6\;{\mu}g/L$, a decrease of 58% compared to a group of Sp rats on uptake of $CdCl_2$ only, in which the $\beta_2$ microglobulin was found to be $4.9\pm0.7\;{\mu}g/L$. According to the results of histopathological observation, the accumulation of mild and localized chronic inflammatory cells in kidney tissues was observed in 50% of the SD rats on uptake of cadmium only. In contrast, only 30% of the SD rats on supplementation with 1% chlorella and uptake of 40ppm $CdCl_2$, representing a histopathological abnormality, and there were no histopathological abnormalities at all in groups of SD rats on supplementation with 5% or 10% chlorella and uptake of 40 ppm $CdCl_2$. In conclusion, protein, calcium, and iron, which account for more than 50% of the total dried chlorella composition, may contribute to the reduction nephrotoxicity by stimulating both inhibited absorption of cadium and increased excretion of accumulated cadmium in kidneys.

Keywords