Efficacy of ulvan on immune response and immuno-antioxidant gene modulation in Labeo rohita against columnaris disease.

This study reports the effect of ulvan enriched diet on the influence of growth, changes in hemato-biochemical indices, improvement of antioxidant system, enhancement of innate-adaptive immunity and modification of immuno-antioxidant genes expression in Labeo rohita against Flavobacterium columnaris. The weight gain (WG) was significantly high (P > 0.05) in unchallenged normal and challenged fish fed with diets enriched with 25 and 50 mg kg-1 ulvan; the FCR was better (P > 0.05) when fed with 50 mg kg-1 enriched diet. In normal fish fed with or without ulvan supplementation was noted 100% survival rate (SR). In both groups, the red blood cell (RBC) and while blood cell (WBC) counts increased significantly (P > 0.05) when fed with 50 mg kg-1 ulvan diet whereas the hemoglobin (Hb) level increased significantly on being fed with 25 and 50 mg kg-1 ulvan diets. The SOD activity was enhanced significantly in both groups fed with any dose of ulvan diets whereas the MDA and GPx activity increased only with 25 and 50 mg kg-1 ulvan diets. The phagocytic (PC) activity significantly increased with any enriched diet and control diet groups while the respiratory burst (RB) activity increased only with 50 mg kg-1 ulvan diet. The alternate complement pathway (ACP), activity of lysozyme (Lyz), and immunoglobuline M (IgM) were better in both groups fed with 50 mg kg-1 ulvan diet. The SOD and GPx antioxidant gene expression were significantly high in both groups fed with any ulvan diet while the Nrf2 gene expression was high with 50 mg kg-1 ulvan diet. The IL-1ß, TNFα, hepcidin, Lyz, and IgM cytokines or proteins mRNA expression were significant in both groups fed with all ulvan supplement diet whereas the ß-2M expression was significant only with 50 mg kg-1 ulvan diet. The present research indicates that both L. rohita groups fed with 50 mg kg-1 ulvan diet significantly improved growth, antioxidant system, immune defense system, and immuno-antioxidant related gene expression against F. columnaris.

Effect of dietary astaxanthin against Aeromonas hydrophila infection in common carp, Cyprinus carpio.

The effect of astaxanthin at 0, 25, 50, and 100 mg kg(-1) incorporated in basal feed on immune response and disease resistance in Cyprinus carpio against Aeromonas hydrophila was investigated. When fed with 25 mg kg(-1) diet, the cumulative mortality was 35% whereas it was 10% and 20% with 50 and 100 mg kg(-1) diets. With all enriched diets the growth rate increased significantly from week 1 to 4 when compared with control. However, the specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER) did not vary significantly from that of the control except with 50 mg kg(-1) diet. When fed with 50 and 100 mg kg(-1) diets the red blood cells, white blood cells, hemoglobin, and hematocrit values significantly increased. However, the serum total protein, albumin, and globulin contents significantly increased only when fed with 50 and 100 mg kg(-1) diets. The phagocytic ratio also significantly raised with 50 and 100 mg kg(-1) diets on week 2 and 4 whereas the phagocytic index significantly increased with all groups only on fourth week. The respiratory burst activity significantly increased in 25 mg kg(-1) diet group on first week whereas in 50 and 100 mg kg(-1) diet groups the activity increased on weeks 2 and 4; a similar trend was observed in the anti-protease activity only on weeks 2 and 4. The serum lysozyme activity and bactericidal activity registered a significant increase with all enriched diets. This study suggests that supplementation of astaxanthin at 50 and 100 mg kg(-1) with the basal diet significantly promotes the growth restores hematology and modulates the immune system in C. carpio against A. hydrophila.

Immune response and disease resistance of carotenoids supplementation diet in Cyprinus carpio against Aeromonas hydrophila.

The effect of carotenoid-supplementation diet on immune response and disease resistance in common carp, Cyprinus carpio against Aeromonas hydrophila at weeks 1, 2, and 4 is reported. The cumulative mortality was 10% when fish were fed with 50 or 100 mg kg(-1) supplementation diets while the un-supplementation diet treated group suffered 90% mortality against the pathogen. The phagocytic activity and complement activity significantly increased with 50 and 100 mg kg(-1) diet groups from weeks 2 and 4 but not in other groups. The reactive oxygen species (ROS) production was significantly enhanced with 50 and 100 mg kg(-1) diets from weeks 1 to 4 while the production of reactive nitrogen species (RNS) enhanced on weeks 2 and 4. The lysozyme activity significantly increased when fed with 50 and 100 mg kg(-1) diets on weeks 2 and all supplementation diets on week 4. These results suggest that diet enriched with carotenoid pigment positively enhance the immune status and protects C. carpio from A. hydrophila infection.

Protective effect of chitin and chitosan enriched diets on immunity and disease resistance in Cirrhina mrigala against Aphanomyces invadans.

The effect of diet enriched with 1% chitin or chitosan on innate immune response and disease resistance in Cirrhina mrigala against Aphanomyces invadans was investigated at weeks 1, 2, and 4. In the un-infected and infected groups the white blood cells (WBC), red blood cells (RBC), haematocrit (Ht), lympocytes, monocytes, and neutrophils significantly increased when fed with 1% chitin (CH) or chitosan (CT) enriched diet from weeks 1 to 4 when compared to control; however, the haemoglobin (Hb) and thrombocytes significantly increased only on weeks 2 and 4. The total protein and albumin levels also significantly increased with any enriched diet on weeks 2 and 4; but the globulin and albumin:globulin ratio increased on week 4 as compared to control; similarly the phagocytic activity significantly increased on weeks 2 and 4 while the lysozyme activity increased from weeks 1 to 4. The complement activity was significantly enhanced in CT and CTI fed groups on weeks 2 and 4. In un-infected fish fed with 1% CH and CT diets, the cumulative mortality was 10% and 5% whereas the infected fish suffered 20% and 25% mortality. The present results suggest that infected fish fed with 1% chitin or chitosan enriched diet modulates the immune system conferring disease resistance in C. mrigala against A. invadans.