Polysaccharides isolated from Digenea simplex inhibit inflammatory and nociceptive responses

• Polysaccharides (PLS) significantly reduced the inflammatory response induced by several mediators.
• PLS reduced the neutrophil migration and decreased the cytokine level into the peritoneal cavity.
• PLS treatment reduced acetic acid-induced abdominal writhing, licking time and increased latency in a hot plate test.

Polysaccharides (PLS) have notably diverse pharmacological properties. In the present study, we investigated the previously unexplored anti-inflammatory and antinociceptive activities of the PLS fraction isolated from the marine red alga Digenea simplex. We found that the PLS fraction reduced carrageenan-induced edema in a dose-dependent manner, and inhibited inflammation induced by dextran, histamine, serotonin, and bradykinin. The fraction also inhibited neutrophil migration into both mouse paw and peritoneal cavity. This effect was accompanied by decreases in IL1-β and TNF-α levels in the peritoneal fluid. Pre-treatment of mice with PLS (60 mg/kg) significantly reduced acetic acid-induced abdominal writhing. This same dose of PLS also reduced total licking time in both phases of a formalin test, and increased latency in a hot plate test. Therefore, we conclude that PLS extracted from D. simplex possess anti-inflammatory and antinociceptive activities and can be useful as therapeutic agents against inflammatory diseases.