Pharmacokinetics of fucoidan and low molecular weight fucoidan from Saccharina japonica after oral administration to mice

The brown seaweed, Sacchairna japonica, has been used in traditional Chinese medicine for over one thousand years. Oral administration of fucoidan or low molecular weight fucoidan (LMWF) from S. japonica could ameliorate kidney dysfunction in chronic kidney diseases and inhibit diabetic vascular complications. In many studies, LMWF was found to be more potent than fucoidan with high molecular weight. However, the pharmacokinetics of LMWF still remains unclear. The purpose of the research is to compare the pharmacokinetics of fucoidan with high molecular weight (136 kDa) with that low molecular weight (9.5 kDa) after oral administration to ICR mice. Since fucose is the main and representative monosaccharide of fucoidans, we evaluate the pharmacokinetics of fucoidan and LMWF by determining the fucose concentration in mice serum. Both fucoidan and LMWF were absorbed following oral administration. Fucoidan and LMWF were provided to mice by oral administration with 60 mg/kg and the maximum Concentration (Cmax) was found at 2.5 h (0.66±0.32 mg/L) for Fucoidan and 1.5 h (1.01±0.56 mg/L) for LMWF, respectively. It seems that LMWF had a higher area under the curve (AUC0−t) and was absorbed more quickly than fucoidan. The estimated bioavailability of LMWF was 28.3% in the mice treated with a single dose of 30 mg/kg. In addition, LMWF was found widely spreaded into different tissues following oral administration and the highest concentration was found in kidney at 19.93±7.02 µg/g. In this study, we first studied the pharmacokinetics of LMWF, in order to help to understand the function of LMWF. And our results shed light on the potential of development of drugs based on LMWF.