Studies On Some Bioactivities Of Several Extracts From Laminaria Japonica And Their Complexes With REE

Rare earth elements (REE) and their complexes have special physical and chemical properties and have been widely applied in nearly every aspect. But the allowance of REE added to food has been strictly limited; REE can't be efficiently used by the creatures, especially in the aquaculrures, due to their insolubility at neutral water system; REE also has potential pollution for the environment. So people pay more and more attention to the state of REE in vivo and the bioactivities of REE combined with biomacromolecules.Due to the recent studies of the REE complexes, the ligands are nearly all mono-sugar. To find richer and more stable ligands is getting to be a hot topic. There are plenty of organic compounds in the waste liquids of extracting polysaccharides from Laminariajaponica. They are rich for O, S,C ,H ,N and P elements and groups, which can be a good and cheap source of ligands to be conjugated with REE, and can be exploited to make various REE complexes with more capabilities.The paper shows the distribution and contents of REE in different components of Laminaria japonica by fractioning and extracting and determined the contents by ICP-AES. The complexes of Ce(SO4)2,Ce(NH4)2(NO3)6 and REE are prepared with several extracts named S serials and the bioactivities in vitro are also determined. The results show that S and their complexes have different abilities of hydrolyzing the proteins and scavenging the free radicals such as super oxide anion radical (O2'~) ; hydroxyl radical ('OH) and DPPH radical.Then, the applications of soluble components of Laminar-ia japonica as the antioxidant for the sesame oil, S1 and its complex with REE as the feed additive to Penaeus vannamei are further studied. The results show that S1 can increase the early antioxidant effect for sesame oil; and nearly all the indexes are markedly improved comparing with the blank control by monitoring the survival rate and the activities of the immune-related enzymes of Penaeus vannamei. Further experiments on the contents of REE in the feed, the whole shrimps and the muscles of the shrimps are determined by ICP-AES. The results illuminate that they are under the limited dosage of the national standard and safe for people if added properly.Studies on the bioactivities of several extracts from Laminaria japonica and their complexes with REE will stimulate the highly-valued utilization of rich resources; improve the immune activities of the animals, decrease the quantities of the antibiotics and also offer a significant reference to illustrating the mechanism of scavenging free radicals in vitro and improve the activities of the immune-related enzymes in vivo.