The efficacy of dietary curcumin on growth performance, lipid peroxidation and hepatic transcription factors in rainbow troutOncorhynchus Mykiss(Walbaum) reared under different stocking densities

Abstract

Curcumin, derived from Curcuma longa, exerts antioxidant, antibacterial, anticancer and immunomodulatory properties. This study was conducted to determine the effect of dietary water-soluble curcumin (0, 200 or 400 mg kg−1) on growth performance and antioxidant status in rainbow trout (Oncorhynchus mykiss, Walbaum) rearing under normal (20 kg m−3) or high (100 kg m−3) stocking density conditions. A significant increase in body weight (FBW), feed intake (FI) and weight gain (BWG) was observed in fish fed with curcumin-supplemented diet at 200 mg kg−1 of diet levels of high stocking density conditions (P < 0.0001), whereas feed conversion ratio (FCR) was not significant. Also, serum and liver malondialdehyde (MDA) levels were decreased by dietary curcumin in crowded fish (P < 0.01, for both). With curcumin supplementation, expressions of heat shock protein 70 (HSP70; P < 0.0001) and hepatic nuclear factor kappa-B (NF-κB; P < 0.01) decreased, whereas expressions of hepatic nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) (P < 0.001, for both) increased in fish exposed to high stocking density. In conclusion, curcumin supplementation alleviates adverse effects of high stocking density on performance through modulating expressions of stress-related nuclear transcription factors in rainbow trout.