Effect of guava leaves on the growth performance and cytokine gene expression of Labeo rohita and its susceptibility to Aeromonas hydrophila infection. Issue 2 (October 2015)

• Record Type: Journal Article
• Authors: Giri, Sib Sankar; Sen, Shib Sankar; Chi, Cheng; Kim, Hyoun Joong; Yun, Saekil; Park, Se Chang; Sukumaran, V.
• Is Part Of: Fish & shellfish immunology. Volume 46:Issue 2(2015:Oct.)
• Page Start: 217
• Page End: 224
• Publication Date: 2015-10
• Subjects: Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2015.05.051
• Languages: English
• ISSNs: 1050-4648

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <p id="abspara0010">The present study aimed to evaluate the effects of <italic>Psidium guajava</italic> L. (guava) leaves on the growth and immune response of the fish species <italic>Labeo rohita</italic> and its susceptibility to <italic>Aeromonas hydrophila</italic> infection. Diets containing five different concentrations of guava leaves (0% [basal diet], 0.1% [G1], 0.5% [G2], 1% [G3], and 1.5% [G4]) were fed to fish (average weight: 11.1 g) for 60 days. Various growth and immune parameters were examined 60 days post-feeding. Fish were challenged with <italic>A. hydrophila</italic> at the end of the trial, and mortalities were recorded over 15 days post-infection. We found that growth parameters such as percent weight gain (657.61 ± 9.74) and specific growth rate (3.37 ± 0.021) were significantly higher in G2 group than in the control (<italic>P</italic> < 0.05). Among the immune parameters examined, lysozyme levels (79.5 ± 5.1 U mL<sup>−1</sup>), leukocyte phagocytic activity (52 ± 4.3%), and alternative complement pathway activity (ACP) (186.1 ± 8.3 U mL<sup>−1</sup>) were significantly high (<italic>P</italic> < 0.05) in G2 fed group; there was, however, no significant effect of guava leaves at any concentration on plasma IgM level. Of the cytokine-related genes examined, interleukin-1beta (IL-1β) and tumour necrosis factor-alpha (TNF-α) were up-regulated in the head-kidney, intestine, and hepatopancreas of fish fed experimental diets, and expression was significantly higher in G2 and G3 than in the control group. In contrast, gene expression of IL-10, transforming growth factor-beta (TGF-β), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and transcription factor nuclear factor-κB (NF-κB) were down-regulated in the treatment groups. Moreover, fish fed the G2 diet exhibited a significantly higher post-challenge survival rate (66.66%). Collectively, these results suggest that dietary supplementation with guava leaves (at 0.5% concentration) could promote growth performance and strengthen immunity of <italic>L. rohita</italic>. Guava leaves therefore represent a promising feed additive for carps in aquaculture.</p> </sec> </abstract>