EFFECTS OF ECHINACEA PURPUREA AND VITAMIN C ON THE HEALTH STATUS, IMMUNE RESPONSE AND RESISTANCE OF OREOCHROMIS NILOTICUS TO AEROMONAS SOBRIA INFECTION
Alshimaa A. Khalil and Mohamed ElHady
Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, Egypt.
|Received 7/ 6/ 2015||
Accepted 14/ 7/ 2015
This study was conducted to investigate the effect of the dietary supplementation of Echinacea purpurea extract (EP) and Vitamin C, either singular or combined on the health status, immune response and resistance of Nile tilapia, Oreochromis niloticus, to Aeromonas sobria (A. sobria) infection. A total number of 120 fish were randomly distributed into four equal groups. The 1st group was fed on a basal diet and was kept as a control. The 2nd and 3rd groups were fed on EP (500 mg kg-1) and Vitamin C (400 mg kg-1) supplemented diets, respectively. While the diet fed to the 4th group was supplemented by a mixture of EP (500 mg kg-1) and Vitamin C (400 mg kg-1). After 28 days of feeding trial, some hematological (Rbcs, Wbcs, Hct and Hb) and non-specific immune parameters (serum bactericidal activity, lysozymes, total proteins, albumin and globulins) were evaluated, as well as a challenge test using a pathogenic A. sobria strain was performed. The results illustrated that, oral administration of Echinacea purpurea (500 mg kg-1) or Vitamin C (400 mg kg-1) significantly enhanced the serum lysozymes and bactericidal activities, as well as exhibited a relatively similar improving effect on the haematological indices assayed and the protection against A. sobria challenge. Whereas, their simultaneous administration showed synergistically enhanced serum lysozymes, bactericidal activities, total proteins and globulins when compared to the use of a single compound, as well as a higher survival was noticed after A. sobria challenge.
Keywords: Echinacea purpurea, Vitamin C, Aeromonas sobria, serum bactericidal activity, lysozymes.