Antihypertensive effects of sodium alginate oligosaccharides

Two types of alginate oligosaccharides (Na-AO and K-AO) were prepared by cleavage of alginate polysaccharide with alginate lyase. In this study, the effects of these oligosaccharides on blood pressure of spontaneously hypertensive rats (SHRs) were investigated. In the Na-AO experiment, Na-AO and NaCl groups were fed a normal diet (CE-2, Clea Japan Inc.) containing 4.0% Na-AO or 1.2% NaCl by weight, respectively. In the K-AO experiment, K-AO and KCl groups were fed CE-2 (control diet) containing 3.0% K-AO or 0.8% KCl by weight, respectively. Systolic blood pressure of the Na-AO group was significantly lower after 8 weeks, compared with the NaCl group. Systolic blood pressure of the K-AO group was also lower than that of the control group, while there was no significant difference between the KCl group and the control group. These results suggest that feeding alginate oligosaccharides suppresses the increase in systolic blood pressure of SHR and that the saccharide moiety itself may be closely related to the antihypertensive effect.