Antioxidant and antihyperlipidemic activities of unique nicotinyl polysaccharide from the green seaweed Ulva pertusa

Nicotinyl derivative of polysaccharide (NU) from the green seaweed Ulva pertusa (Chlorophyta) has unique structure and strong antioxidant activity in vitro . In the present study, in vivo antioxidant and antihyperlipidemic activities were tested in the livers of hyperlipidemic mice. Activity levels of superoxide dismutase, glutathione peroxidase (GSH-P X ), catalase, and malondialdehyde were observed. At the 500 mg/kg dose, NU showed strongest antioxidant activity compared with the hyperlipidemic mice. This dose also increased GSH-Px compared with ulvan. NU at a dose of 125 mg/kg showed the strongest antihyperlipidemic activity, significantly decreasing total cholesterol (TC), triglyceride (TG), and low-density lipoprotein levels (LDL-C), as well as elevating high density lipoprotein. The antioxidant and antihyperlipidemic mechanisms of NU may be related to the nicotinyl group in its chemical structure. NU may be effective in protecting liver tissue from the damage of a cholesterol-rich diet in mice and may be of use as a novel antihyperlipidemic agent.