Plant polysaccharides used as immunostimulants enhance innate immune response and disease resistance against Aeromonas hydrophila infection in fish

• Published in: Fish & shellfish immunology Vol. 59; pp. 196 - 202
• Main Authors: Wang, Erlong, Chen, Xia, Wang, Kaiyu, Wang, Jun, Chen, Defang, Geng, Yi, Lai, Weimin, Wei, Xianchao
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2016
• Subjects: Adjuvants, Immunologic - administration & dosage; Adjuvants, Immunologic - pharmacology; Aeromonas hydrophila; Aeromonas hydrophila - physiology; Animal Feed - analysis; Animals; Carps; Diet - veterinary; Disease resistance; Disease Resistance - drug effects; Drugs, Chinese Herbal - administration & dosage; Drugs, Chinese Herbal - pharmacology; Ficus - chemistry; Ficus carica; Fish Diseases - drug therapy; Fish Diseases - immunology; Fish Diseases - microbiology; Food Additives; Freshwater; Gram-Negative Bacterial Infections - drug therapy; Gram-Negative Bacterial Infections - immunology; Gram-Negative Bacterial Infections - microbiology; Gram-Negative Bacterial Infections - veterinary; Immunity, Innate - drug effects; Innate immune response; Plant polysaccharides; Polysaccharides - administration & dosage; Polysaccharides - pharmacology; Radix isatidis; Random Allocation; Schisandra; Schisandra - chemistry; Schisandra chinensis; Radix isatidis; Disease resistance; Schisandra chinensis; Ficus carica; Innate immune response; Plant polysaccharides
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2016.10.039

Plant polysaccharides (PPS) are an important medicinal plant product, and play a major role in preventing and controlling infectious microbes in aquaculture. The present study investigated the effect of three PPS; Ficus carica polysaccharides (FCPS), Radix isatidis polysaccharides (RIPS), and Schisandra chinensis polysaccharides (SCPS), used as feed additives, on innate immune responses and disease resistance against Aeromonas hydrophila in crucian carp. Results show that crucian carp fed with these PPS showed significant (p < 0.05) enhancement of their innate immune response including leukocyte phagocytosis activity, serum bactericidal activity, lysozyme activity, total protein level, complement C3, and superoxide dismutase activity compared with the control group. Their degree of influence on these immune parameters was in the order of FCPS > RIPS > SCPS, except for lysozyme activity (RIPS > FCPS > SCPS). In addition, fish cumulative mortalities in the three treatment groups were remarkably lower than in the control group (95%) when challenged with A. hydrophila, relative percent survivals were 57.9%, 47.4%, and 42.1% in FCPS, RIPS, and SCPS groups, respectively. These results suggest that FCPS, RIPS, and SCPS used as immunostimulants are capable of enhancing immune responses and disease resistance against A. hydrophila in crucian carp, and that FCPS was the most effective. The findings from this study will help accelerate research of this topic, and promote the application and development of immunostimulants, such as Chinese herbs, in aquaculture. [Display omitted] •FCPS, RIPS and SCPS were successfully extracted and purified with high contents.•Three PPS used as feed additives enhance innate immune response in crucian carp.•Three PPS used as feed additives enhance disease resistance against A. hydrophila.•FCPS, RIPS and SCPS conferred RPS with 57.9%, 47.4% and 42.1%, respectively.