Effect of berberine hydrochloride on grass carp Ctenopharyngodon idella serum bactericidal activity against Edwardsiella ictaluri

Bactericidal activity of grass carp (Ctenopharyngodon idella) serum was significantly enhanced when pre-treated with 15 mg l?1 or 3 mg l?1 of berberine hydrochloride, an effective component of several commonly used herbal medicines in aquaculture. The complement consumption experiment demonstrated that berberine hydrochloride can certainly activate fish complement system. The results of both experiments suggested that berberine hydrochloride could enhance the serum bactericidal activity in grass carp by activating the complement system and indicating the potential in the prevention or treatment of fish diseases.