Effects of Ginkgo biloba extract on growth, antioxidant capacity, immunity, and lipid metabolism of Exopalaemon carinicauda cultured in extremely low salinity

This study evaluated the effects of Ginkgo biloba leaf extract (GBE) on Exopalaemon carinicauda reared under low salinity. Shrimps were fed diets supplemented with 0.0 (control), 1.0, 2.0, or 4.0 g/kg GBE for 30 days. The results indicated that, while GBE did not significantly enhance growth performance, it markedly improved several physiological parameters. Supplementation at 1.0–2.0 g/kg GBE did not affect hemolymph ALT or AST activities ( P > 0.05), 4.0 g/kg dose resulted in a significant increase ( P < 0.05). Notably, GBE elevated the population of B-cells while lowering that of R-cells, without causing significant hepatopancreatic damage. Importantly, 2.0 g/kg GBE enhanced antioxidant status, as evidenced by increased activities of GSH-Px, CAT, POD, and T-AOC, and decreased H₂O₂ levels in hemolymph and hepatopancreas ( P < 0.05). Immunity-related genes and enzyme activities were also significantly upregulated at 2.0 g/kg ( P < 0.05). The expression of lipogenic genes, gpat and fabp , was significantly suppressed of GBE treated groups compared to the control ( P < 0.05). In contrast, the expression of acc and gk remained unaltered ( P > 0.05). Notably, the expression of fas exhibited a biphasic response, with initial up-regulation at doses of 1.0 and 2.0 g/kg followed by a significant decline at the 4.0 g/kg dose ( P < 0.05). Concurrently, GBE markedly upregulated the expression of the lipolytic genes lps and hsl ( P < 0.05), consistent with the decrease of hemolymph lipid. GBE downregulated the expression of cyp2l1 , cyp2u1 , cyp3a25 , and cyp4c ( P < 0.05). Conversely, it markedly upregulated the expression of cyp6a8 , cyp9e2 , and cyp12a2 ( P < 0.05). In summary, despite not improving growth performance of E. carinicauda , 1.0–2.0 g/kg GBE exerted beneficial effects on antioxidant status, immune function, and lipid metabolism. The optimal recommended level of GBE supplementation is 2.0 g/kg in the diet of E. carinicauda . • Dietary supplementation with GBE significantly increased the population of blister-like cells. • 1.0–2.0 g/kg GBE exerted beneficial effects on antioxidant status, immune function, and lipid metabolism. • The optimal recommended inclusion level of GBE supplementation is 2.0 g/kg.