Open AccessEvaluation of Chlorella as a Decorporation Agent to Enhance the Elimination of Radioactive Strontium from Body
Author(s) -
Kenji Ogawa,
Tadahisa Fukuda,
Joan C. Han,
Yoshihisa Kitamura,
Kazuhiro Shiba,
Akira Odani
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0148080
Subject(s) - strontium , radiochemistry , isotopes of strontium , strontium 90 , chemistry , radioactive waste , environmental science , nuclear chemistry , radionuclide , physics , organic chemistry , nuclear physics
Background Release of radionuclides, such as 137 Cs and 90 Sr, into the atmosphere and the ocean presents an important problem because internal exposure to 137 Cs and 90 Sr could be very harmful to humans. Chlorella has been reported to be effective in enhancing the excretion of heavy metals; thus, we hypothesized that Chlorella could also enhance the elimination of 137 Cs or 90 Sr from the body. We evaluated the potential of Chlorella as a decorporation agent in vitro and in vivo , using 85 Sr instead of 90 Sr. Methods In vitro experiments of adsorption of 137 Cs and 85 Sr to Chlorella were performed under wide pH conditions. The maximum sorption capacity of Chlorella to strontium was estimated using the Langmuir model. A 85 Sr solution was orally administrated to mice pretreated with Chlorella . At 48 h after 85 Sr administration, the biodistribution of radioactivity was determined. Results In the in vitro experiments, although 85 Sr barely adsorbed to Chlorella at low pH, the 85 Sr adsorption ratio to Chlorella increased with increasing pH. The maximum sorption capacity of Chlorella to strontium was 9.06 mg / g. 137 Cs barely adsorbed to Chlorella under any pH conditions. In the biodistribution experiments, bone accumulation of radioactivity after 85 Sr administration was significantly decreased in the Chlorella pretreatment group compared with the non-treatment control group. Conclusions In conclusion, these results indicated that Chlorella could inhibit the absorption of 90 Sr into the blood and enhance the elimination of 90 Sr from the body through adsorption in intestine. Further studies are required to elucidate the mechanism and the components of Chlorella needed for adsorption to strontium and could promote the development of more effective decorporation agents.