Bio-functions of carvacrol-supplemented feeds on lipopolysaccharide-induced rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

To investigate the effects of carvacrol supplementation diets in rainbow trout induced by LPS, we measured gene expressions relative to pro-inflammatory and apoptosis in kidney and liver. Fish, which that were studied by four different treatments with three replicates each, was 44.71±1.33 gr. All fish were infected with E. coli LPS (25 µg ml-1) expect control and only carvacrol containing diet fed (100 µg ml-1 diet) group (CAR). The last group was the infected fish fed carvacrol supplemented diet (+CAR). Kidney and liver tissues were removed 3 day after to determine the levels of interleukin-1β (IL-1β), interferon gamma (INF-γ), caspase 3 (Cas 3), caspase 8 (Cas 8) and by Real-Time PCR analyses. IL-1β expressions of both kidney and liver was significantly decreased (12.9 and 2.14 fold, respectively) in LPS treated cells (P<0.05). While IFN-γ expression was up regulated in kidney, it had down regulation in liver. LPS decreased both Cas 3 and Cas 8 expressions but increased in liver. +CAR increased expressions of IL-1β and IFN-γ compared to control (up to 2-3 fold) in all tissues but not caspase gene expressions were similar in control. In all tissues, IL-1β and IFN-γ expressions increased in +CAR, expect IFN-γ in kidney. Then both genes returned to control levels.  However, Cas 3 and 8 expressions including apoptosis was induced by up-down regulations in all tissues compared to LPS-injected fish. The present results showed carvacrol had pro-inflammatory and apoptotic effects on especially liver tissue of LPS induced inflammation model of Oncorhynchus mykiss.