Antimicrobial and Antibiofilm Activities of Sulfated Polysaccharides from Marine Algae against Dental Plaque Bacteria.

Dental plaque biofilms cause various dental diseases; therefore, inhibiting the growths of the dental plaque bacteria which produce biofilms can be a strategy for preventing dental disease. Certain sulfated polysaccharides from marine algae exert antimicrobial activities against human bacterial pathogens in addition to their physiological benefits. On the basis of these observations, the antimicrobial and antibiofilm activities of sulfated polysaccharides from different marine algae were evaluated against dental plaque bacteria. Among the sulfated polysaccharides, a fucoidan from Fucus vesiculosus showed notable antimicrobial activities against the selected dental plaque bacteria, including some foodborne pathogenic bacteria. The minimum inhibitory concentrations were of 125 to 1000 µg mL-1. Regarding the antibiofilm activity, the fucoidan at the concentrations of above 250 µg mL-1 completely suppressed the biofilm formations and planktonic cell growths of Streptococcus mutans and S. sobrinus. However, no eliminative effect on the completed biofilm was observed. The fucoidan consisted of almost fucose base polysaccharide containing approximately 14.0% sulfate content. The average molecular weight of the fucoidan was changed by heat treatment (121 °C for 15 min) and it affected the antimicrobial activity.

Effects of the Polysaccharide from the Sporophyll of Brown Alga Undaria Pinnatifida on Serum Lipid Profile and Fat Tissue Accumulation in Rats Fed a High-Fat Diet.

We investigated the effects of the polysaccharide from the sporophyll of a selected brown alga Undaria pinnatifida on serum lipid profile, fat tissue accumulation, and gastrointestinal transit time in rats fed a high-fat diet. The algal polysaccharide (AP) was prepared by the treatment of multiple cellulase-producing fungi Trichoderma reesei and obtained from the sporophyll with a yield of 38.7% (dry basis). The AP was mostly composed of alginate and fucoidan (up to 89%) in a ratio of 3.75:1. The AP was added to the high-fat diet in concentrations of 0.6% and 1.7% and was given to male Sprague-Dawley rats (5-wk-old) for 5 wk. The 1.7% AP addition notably reduced body weight gain and fat tissue accumulation, and it improved the serum lipid profile, including triglycerides, total cholesterol, and very low-density lipoprotein-cholesterol. The effects were associated with increased feces weight and shortened gastrointestinal transit time. In addition, the lipid peroxidation of the liver was decreased in both groups.