In vivo protective effect of Porphyra yezoensis polysaccharide against carbon tetrachloride induced hepatotoxicity in mice

To study the protective effect and possible mechanism of Porphyra yezoensis polysaccharide (PYP) in hepatotoxicity mice, acute liver injury was successfully induced by injecting 0.2% carbon tetrachloride (CCl4) intraperitoneally. Levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum and liver homogenate, content of malondialdehyde (MDA), activities of total superoxide dismutase (T-SOD) in liver were measured by biochemical methods. Liver index was calculated and pathological changes of the liver tissue were observed microscopically. PYP was found to significantly decrease the activities of ALT and AST (P < 0.05), to remarkably lower the liver indexes and MDA level in hepatical tissues in mice (P < 0.05), and to upregulated the lower T-SOD level in liver homogenate (P < 0.01). Furthermore, histologic examination showed that PYP could attenuate and the extent of necrosis, reduce the immigration of inflammatory cells. PYP plays a protective action against hepatotoxicity induced by CCl4 in mice, and its mechanisms may be related to free radical scavenging, increasing SOD activities and anti-lipid peroxide.