The immunomodulatory effect of saccharo-myces cerevisiae, β-glucan or laminaran on african catfish (clarias gariepinus)‎ after immunosuppression induced by mercury

Abstract EN

This study was conducted on a total number of 100 African catfish (Clarias gariepinus) weighing 150-200 gm.

The experimental fish were randomly divided into five equal groups, each containing 20 fish in well aerated glass aquaria.

The first group (Gp.

1) acted as a control.

Gps.

(2-5) were subjected to sub lethal concentration of mercuric chloride 0.25 ppm in water.

After one week of pollutant treatment, the Gps.

(1 and 2) were fed on a control ration.

Gps (3, 4 and 5) were fed on a ration containing, Saccharomyces cerevisiae, β-glucan and Laminaran at a dose of 10 gm / Kg, 0.1 % and 0.1 % respectively for 21 days.

Random five fish were sampled from each group at 7, 14 and 21 days of treatment with Saccharomyces cerevisiae, β-glucan and Laminaran.

Heparanized blood sample to study the non-specific defense mechanism (neutrophils adhesion test, lymphocyte transformation test, total and differential leukocytes count) were obtained.

Serum preparation of remaining blood was done to be used for serum lysozyme assay and protein electrophoresis.

Also skin mucus samples were collected from all experiment groups for lysozyme assay.

Peritoneal macrophages were isolated and oxidative burst were assayed.

Neutrophils adhesion cells, were significantly increased at 14 and 21 days in Saccharomyces cerevisiae, β-glucan and Laminaran treated groups in compared with immunosuppressive group (GP.2).

Macrophages oxidative burst were significantly increased in Saccharomyces cerevisiae at 14 and 21 days while in β-glucans and Laminaran groups were significantly increased all over the experiment period in compared with immunosuppressive group.

Lymphocytes transformation index and serum lysozyme were significantly increased in Saccharomyces cerevisiae at 21 days only while in β-glucan and Laminaran groups were significantly increased at 14 & 21 days in compare with (GP.2).

Total leukocytes were significantly increased at 21 days in Saccharomyces cerevisiae and Laminar and groups in compared with immunosuppression group (Gp.2).

In β-glucan group, total leukocytes were significantly increased at 14 and 21 days in compared with Gp.2.

γ-globulin levels were increased in Saccharomyces cerevisiae, β-glucans and Laminaran groups at 21 days with respect to GP.2.

Mucus lysozyme significantly increased in all immunostimulants treated groups at 21days only in compared with Gp.2.

This study provide that Saccharomyces cerevisiae, β-glucans and Laminaran were able to enhance the non-specific immunity of African catfish (Clarias gariepinus) efficiently, and we concluded these results support the possible use of whole yeast as an immunostimulants for farmed catfish.