Immuno-physiological effects of dietary beta-glucan on Rohu, Labeo rohita challenged with Aeromonas veronii

Abstract

Beta-glucans have immense potential to stimulate immune modulation in fish by being injected intramuscularly, supplemented with feed or immersion routes of administration. Here, we looked at how supplementing the diet of Rohu carp, Labeo rohita, with beta-glucan, influenced the immune function. A beta-glucan-supplemented diet containing 10% mushroom powder was administered for 120 days. Afterward, analyses were conducted on different immunological parameters such as antioxidants, respiratory burst, reactive oxygen species (ROS), alternative complement activity, and serum immunoglobulin, which resulted significant increases (p < 0.05 and p < 0.01) for the beta-glucan fed immune primed L. rohita, indicating enhanced immunity. Additionally, analyzing various hematological parameters such as erythrocytes and leukocytes count were assessed using standardized methods to elucidate the immunomodulatory effects, indicating a positive effect of beta-glucan on overall fish health. Furthermore, the bacterial challenge test with a 1.92×104 CFU/ml intramuscular dose of Aeromonas veronii showed an enhanced disease-defending system as total serum protein and lysozyme activity levels accelerated significantly (p < 0.01). Nevertheless, beta-glucan ameliorated the stress indicating parameters like Acetylcholinesterase (AChE), serum glutamic pyruvic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT) enzyme activities results suggested the fish's physiology was unaffected. Therefore, it was determined that adding dietary beta-glucan supplementation could significantly boost up the immune responses in Rohu carp.