Effect of seeds of Achyranthes aspera on the immune responses and expression of some immune-related genes in carp Catla catla

• Achyranthes aspera seeds showed immunostimulatory properties in catla.
• Tissue-specific expression pattern of different immune-related genes.
• In kidney and gill, TNFα, lysozyme c and g were up-regulated.
• In hepatopancreas, IL-10, lysozyme c and g were up-regulated.
• The expression of TNFα and IL-10 in the kidney was inversely related.

Evaluation of functional mechanism of immunostimulant in fish is essential for realizing their therapeutic potential. The impact of dietary supplementation of seeds of Achyranthes aspera on the immune system of Catla catla was studied. Catla (37.73 ± 6.7 g) were fed with test diets containing 0.5 (D1) and 1.0% (D2) seeds of A. aspera and control diet (D3) for 50 days. Then fish were immunized with heat-killed Aeromonas hydrophila. Blood and tissue samples were collected after 7 days of immunization. Three fish were sacrificed for each parameter. Respiratory burst activity, bactericidal activity and antibody response were significantly (P < 0.05) higher in test diets fed catla compared to the control one. Nitric oxide synthase and serum lysozyme were significantly (P < 0.05) higher in fish fed with diet D2 compared to the other treatments. There were up-regulations of TNFα, lysozyme c and g gene expressions in kidney and IL-10, lysozyme c and g expressions in hepatopancreas of test diets fed fish compared to the control one. The expression of IL-10 was down-regulated in the kidney of D2 diet fed fish compared to others. In the gill, significantly (P < 0.05) higher expressions of TNFα was found in D1 diet feed fish and lysozyme c and in D2 diet fed fish compared to the other groups. This study showed tissue-specific gene expression pattern in catla. An inverse relationship was found between the expression of TNFα and IL-10 in kidney of catla.