“Effects of Torenia concolor on immune regulation and resistance to megalocytivirus in barramundi (Lates calcarifer) (7151)”

Effects of Torenia concolor on immune regulation and resistance to megalocytivirus in barramundi (Lates calcarifer)

Red seabream iridovirus (RSIV) is a highly pathogenic virus that affects farmed barramundi in Asia, leading to high mortality and significant economic losses. Torenia concolor (TC) has bioactive compounds with anti-inflammatory and antiviral properties. In this study, we examined the in vitro mechanisms by which boiled water extracts of TC (TCE) exert anti-RSIV activity. The results indicated that TCE could inhibit RSIV infection by blocking the RSIV receptor and suppressing viral replication, thereby exerting antiviral effects. To evaluate the effects of TC on immune regulation and anti-RSIV activity in vivo, barramundi were fed diets containing different concentrations of TC, including 0 g/kg (TC0), 5 g/kg (TC5), or 10 g/kg (TC10) for 28 days. The results revealed that the supplementation of TC had no significant effect on barramundi growth performance. In addition, immune gene expression (IL-1β, TNF-α, IgM, Mx, SOD, CAT, C3, and lysozyme) was analyzed in the head kidney and spleen of barramundi fed with TC-containing diets for 1, 2, 3, and 4 weeks. The results showed that the gene expression of IL-1β, Mx and C3 was significantly increased in TC5 and TC10 groups. Furthermore, after feeding with TC for 4 weeks and challenging with RSIV, the supplementation with TC could lower the mortality in RSIV-challenged barramundi. In conclusion, TC regulated the immune response and enhanced resistance to RSIV in barramundi, highlighting its potential as an antiviral functional feed additive in aquaculture.

1. LIN, ZHE-LI, INSTITUTE OF FISHERIES SCIENCE, NATIONAL TAIWAN UNIVERSITY, TAIPEI 10617, TAIWAN, Presenter
2. WU, YU-CHI, INSTITUTE OF FISHERIES SCIENCE, NATIONAL TAIWAN UNIVERSITY, TAIPEI 10617, TAIWAN, Author