In Vitro Activation of Epinephelus Malabaricus Head-Kidney Leukocytes by Angelica Sinensis Polysaccharide

Phagocytic, respiratory burst, bactericidal, and proliferative activity stimulation of Epinephelus malabaricus head-kidney leukocytes by Angelica sinensis polysaccharide (ASP) were evaluated in vitro. Leukocytes were incubated for 2, 6, 12 and 24 h in the presence of 0, 10, 100 and 1000 mu g/mlASP or 100 mu g/ml lipopolysaccharide (LPS) before phagocytic and respiratory burst activity assay, and for 24 h with 0, 100, 1000, 10000 mu g ASP/ml before bactericidal activity detection. Meanwhile, leukocytes were incubated for 24 and 48 h followed by proliferative activity evaluation. The results showed that ASP boosted leukocytes phagocytic, respiratory burst, bactericidal, and proliferative activity significantly in a dose-dependent manner. Leukocytes incubated with 100 mu g/ml ASP exhibited the highest phagocytic and respiratory burst activity. Leukocytes incubated with 1000 mu g/ml ASP showed the highest bactericidal activity, which was followed by leukocytes incubated with 100 mu g/ml ASP. Leukocyte proliferation was significantly enhanced with increasing concentration of ASP, and reached the highest value with 10000 mu g/ml ASP. Compared with LPS in the same concentration (100 mu g/ml), ASP exerted a stronger stimulating effect on respiratory burst but was weaker on proliferation in E. malabaricus leukocytes. These findings indicate that ASP prototype enhanced cellular immunity of E. malabaricus, and potentially contributed to the pursuit of environmentally friendly prophylactic measures to enhance the immunity of E. malabaricus.