Effects of dietary hawthorn extracts supplementation on lipid metabolism, skin coloration and gut health of golden pompano (Trachinotus ovatus)

Hawthorn fruit has long been used as a functional food in China due to its effects of increasing appetite, promoting digestion and protecting the gastrointestinal tract. The present study was conducted to assess the impact of dietary hawthorn extract (HTE) supplementation on plasma biochemical indices, proximate body composition, skin coloration, intestinal morphology and changes in mRNA expression of immune-related genes and tight junction proteins genes in the intestine of golden pompano. Basal diets supplemented with HTE at 0, 0.50, 1.00, 2.00, 4.00 and 10.00 g kg−1 were fed to golden pompano for eight weeks. The study showed dietary HTE supplementation had hypolipidemic effects by reducing plasma cholesterol, triglyceride and low density lipoprotein content and improved skin coloration by increasing yellowness values of the ventral skin color of golden pompano. Meanwhile, dietary supplementation of 0.50 and 1.00 g kg−1 HTE could improve gut morphology by increasing villus length, villus width and muscle thickness, and enhance barrier function by increasing tight junction protein genes mRNA levels. However, dietary 10.00 g kg−1 HTE supplementation not only caused damage to intestinal morphology and barrier function, but also induced oxidative stress and inflammatory response. Our study demonstrated that dietary 0.50 and 1.00 g kg−1 HTE supplementation was beneficial for skin coloration and intestinal health of golden pompano.