Abstract
Bioactive polysaccharides extracted from brown seaweeds have potent antioxidant, antitumor, antibacterial, antiviral, anti-inflammatory activities and nanomedicine applications. In the present study, we have made an attempt to overcome the instability and bioavailability problem of exopolysaccharides extracted from brown seaweed (Sargassum longifolium) by nanoencapsulation technology to enhance its therapeutic applications. Exopolysaccharides was encapsulated in orange oil nanoemulsion (NE) prepared by ultra-sonication method and nanostructured lipid carrier (NLC) prepared by hot solvent diffusion method. The encapsulation efficiency of nanoemulsion was 67.29% and of nanostructured lipid carrier was 78.7%. The prepared nano carriers have particle size 178 nm (NE), 153 nm (NLC) and zeta potential -43.9 mV (NE), -60 mV (NLC). In vitro release kinetics of exopolysaccharides from NE (80%) and NLC (95%) was found to be slow and sustained release which indicates increase in bioavailability. The cytotoxic effect of seaweed polysaccharide, nanocarriers loaded with seaweed polysaccharide was analyzed by MTT method in colon cancer (HCT 116) cell lines with the results revealing that seaweed polysaccharide encapsulated with NLC (80%) was superior to that encapsulated with orange oil nanoemulsion (70%). This is the first report demonstrating the potential of brown seaweed exopolysaccharide encapsulated in orange oil nanoemulsion and nanostructured lipid carrier for its biomedical application.