Impact of cinnamaldehyde on innate immunity and immune gene expression in Channa striatus against Aphanomyces invadans.

The effect of cinnamaldehyde (CM) enriched diet on immunity and cytokine gene expression in Channa striatus against Aphanomyces invadans is reported. C. striatus was uniformly divided into eight groups (n = 25 fish each) and fed with formulated diets with 0, 5, 10, and 15 mg kg-1 CM enriched diet. In healthy and infected groups fed with 5 mg kg-1 diet the leukocytes count increased significantly after 4th week; with 10 mg kg-1 CM diet the increase manifested after 6th week, but with 15 mg kg-1 not even after 8th week. In both groups, 5 mg kg-1 CM diet resulted in a significant increase in the serum total protein, albumin, and globulin levels after 4th week, whereas with other diets this effect was observed only after 6th week. Similarly, with any enriched diet the lysozyme activity increased significantly, but with 15 mg kg-1 CM diet only after 6th week. In both groups the complement activity and lymphocyte production increased significantly when fed with 5 mg kg-1 CM diet after 4th week while with other enriched diets only after 6th week. The phagocytic activity increased significantly in both groups fed with 5 mg kg-1 CM diet after 6th week, whereas the SOD activity increased after 4th week. The IgM production increased significantly in both groups fed with 5 mg kg-1 CM diet after 2nd week, while with 5 and 10 mg kg-1 CM diet after 4th week. In both groups, the expression of CXCR3α was significant on 4th week when fed with 10 mg kg-1 CM diet, while in the healthy group fed with 15 mg kg-1 CM diet the expression manifested earlier than 4th week. However, when fed with 10 and 15 mg kg-1 CM diets the increase was observed on 6th week; whereas, the expression of MHC-I reached the maximum on 6th week with any enriched diet. The results indicate that in C. striatus the innate immunity and expression of cytokine and immune related genes were significantly modulated when fed with 5 mg kg-1 CM diet on 4th week against A. invadans. Crown