© 2016 The rapid development of the aquaculture industry has global concerns with health management and control strategies to prevent and/or treat diseases and increase sustainability standards. Saprolegniosis is a disease caused by Saprolegnia parasitica, and is characterized by promoting an immunosuppression in the host. This study evaluated in vitro the extract and one active compound (polygodial) of Drimys winteri, a Chilean medicinal tree as a potential early immunostimulatory aid in Saprolegniosis control. Atlantic salmon (Salmo salar) head kidney cells (ASK-1) were incubated with both extract and pure polygodial before exposure to S. parasitica mycelium, and the expression of the immune-related genes interleukin 1β (IL-1β), interferon α (IFNα), and major histocompatibility complex II (MHCII) was evaluated. Both evidenced immunomodulatory capacities by increasing gene expressions. This immunomodulation related to a mitigatory action counteracting the immunosuppressing effects of S. parasitica. Despite that most immune-related genes were up-regulated, the down-regulation of MHCII, characteristic of S. parasitica infection, was lessened by pre-incubation with the compounds. This study provides the first insight on the potential of D. winteri bark extract as a possible immunomodulatory and defensive strategy against this oomycete infection in fish.
Pereira-Torres, D., Gonçalves, A. T., Ulloa, V., Martínez, R., Carrasco, H., Olea, A. F., Espinoza, L., Gallardo-Escárate, C., & Astuya, A. (2016). In vitro modulation of Drimys winteri bark extract and the active compound polygodial on Salmo salar immune genes after exposure to Saprolegnia parasitica. Fish and Shellfish Immunology, 103-108. https://doi.org/10.1016/j.fsi.2016.10.035