Dietary naringin attenuates adverse effects of high fat diet on growth performance, antioxidative capacity, inflammatory response and apoptosis in the intestine of largemouth bass (Micropterus salmoides)

Although the administration of high fat diet (HFD) is employed in aquaculture to confer a protein-sparing effect, their chronic utilization frequently elicits oxidative stress, detrimentally affecting piscine health and growth performance. The antioxidative and anti-inflammatory capacities of naringin (Nar), a citrus-derived flavanone, have motivated extensive investigation. Here, we explored the effect of dietary naringin and HFD on growth performance, antioxidative capacity, and intestinal health of largemouth bass. The 2 × 3 two factorial experiment was designed, with dietary lipid at two levels and naringin at three levels. Thus, six experimental diets were formulated to include normal lipid diet (10.5 % fat, Con), control with 1.25 g/kg and 2.5 g/kg Nar (Con+Nar1.25, Con+Nar2.5), high fat diet (18.5% fat, HFD), HFD with 1.25 g/kg and 2.5 g/kg Nar (HFD+Nar1.25, HFD+Nar2.5). The feeding experiment continued for 10 weeks. Compared with the Con group, HFD inhibited growth performance, increased MDA content and up-regulated intestinal mRNA expression of keap1a , keap1b , il-6 , il-8 , tnf-α , il-1β , badb, baxa , caspase3a , caspase8 and caspase9 , but decreased T-AOC, T-SOD, CAT and GPx activities and down-regulated intestinal mRNA expression of sod1 , sod2 , gpx1 , cat , nrf2 , tgf-β , il-10 , zo-1 , claudin-1 , claudin-4 , occloud , muc17 , muc5ac , muc2, bcl-2b, and bcl-xl . Compared to the Con and HFD group, dietary naringin addition improved growth performance, feed intake, intestinal histology, increased T-AOC, T-SOD, CAT and GPx activities, up-regulated intestinal mRNA expression of sod1 , sod2 , gpx1 , cat , nrf2 , tgf-β , il-10 , zo-1 , claudin-1 , claudin-4 , occloud , muc17 , muc5ac , muc2 , bcl-2b and bcl-xl , but decreased FCR and MDA content, down-regulated keap1a , keap1b , il-6 , il-8 , il-1β , tnf-α mRNA expression. Based on these observations above, HFD has an interaction with Nar. HFD causes oxidative stress, inflammation, barrier damage and apoptosis in the intestines of largemouth bass, while Nar can specifically alleviate these adverse effects. Moreover, the protective effect of Nar is more significant under HFD, improving the growth performance and intestinal health of the fish. • High fat diet inhibited growth performance and damaged intestinal health in largemouth bass. • Dietary naringin addition alleviated negative effects of growth performance and intestinal health induced by high fat diet. • 0.125% and 0.25% of dietary naringin addition alleviated these negative effects on largemouth bass by high fat diet. • Naringin is a potential functional additive in aquafeeds to enhance fish health.