EFFECT OF NATCONTROL™ ON IMMUNITY MARKERS GENE EXPRESSION AND THE PROTECTION AGAINST IN VITRO INFECTION WITH P. salmonis
Background: NatControl™ is a natural extract of plant origin of the family Acanthaceae, standardized in specific labdane diterpenoid. Its immunostimulating properties have been studied in several models, but their effect on fish has been little studied. Therefore, this study aims to determine the in vitro properties of the extract in SHK-1 macrophages cells from Salmo salar.
Methods: The effect of NatControl™ on the expression of innate immunity markers associated with antibacterial and antiviral mechanisms in SHK-1 cells (derived from Salmo salar cephalic kidney) was evaluated. For this, a stimulation kinetics was performed with the product and the levels of IL-12 and IFNI were quantified by RT-qPCR. Also, the protective effect of this formulation was evaluated by an in vitro challenge with P. salmonis strain LF-89 (104 and 106 bacteria / mL). The percentage of cytotoxicity was calculated by a colorimetric assay that measures LDH enzyme release into the culture medium of the treated and infected cells.
Results: Our results show that 5 nM and 10 nM NatControl™ exhibit the greatest effect on the expression of IL-12 and IFN-I in SHK-1 cells at 2 h and 12 h stimulation times. Also, against the challenge with P. salmonis, a protective effect was noticed on cells pretreated for 6 h with NatControl, lasting until day 20 post-infection. It should be noted that the cells treated with the respective treatments with NatControl™ presented negative values of toxicity at the beginning of the experiment, which could be due to a protective effect of the products on cell viability.
Conclusion: We suggest a potential immunostimulating effect of NatControl™ on SHK-1 cells and a protective effect against infection with P. salmonis. It would be interesting to develop future studies to deepen the immunostimulating and protective effect of this compound in fish models in response to infections with P. salmonis.
Our special thanks to HP Ingredients for giving us samples of NatControl™