Effects of dietary supplementation of astaxanthin (Ast) on growth performance, activities of digestive enzymes, antioxidant capacity and lipid metabolism of large yellow croaker ( Larimichthys crocea ) larvae

Abstract

A 30-day feeding experiment was operated to evaluate the impact of astaxanthin (Ast) on growth performance, activities of digestive enzymes, antioxidant responses and lipid metabolism of large yellow croaker (Larimichthys crocea) larvae. Four microdiets (isonitrogenous and isolipidic) were formulated with graded Ast levels (0, 20, 40 and 80 mg/kg) in form of Haematococcus pluvialis powder (0, 0.4, 0.8 and 1.6 g/kg).Results showed that the specific growth rate of larvae was significantly enhanced by supplementation of 80 mg/kg Ast compared to the control group. Meanwhile, the Ast supplementation could significantly improve the digestive capacity of larvae through increasing activities of digestive enzymes, including trypsin in larvae pancreas segments (PS) and intestinal segments (IS), lipase, and alkaline phosphatase in brush border membranes compared to the control group. In terms of antioxidants, Ast supplementation significantly advanced the antioxidant capacity through increasing the activity of total antioxidant capacity and catalase, and reducing content of malondialdehyde. The activity of lysozyme and nitric oxide content of larvae were significantly increased by Ast supplementation compared to the control group. Furthermore, the triglyceride content in visceral mass was significantly reduced by Ast supplementation probably through up-regulating expression of lipid catabolism-related genes (cpt1, lpl, hl, aco, and pparα), and down-regulating expression of lipogenesis-related genes (fas, dgat2, and srebp1) and lipid transport-related genes (fabp11, apoB100, and mtp).In summary, appropriate supplementation of Ast (40-80 mg/kg) could improve the growth performance of large yellow croaker larvae through enhancing of digestive enzymes activities, antioxidant capacity and promoting lipid utilization.

Effects of supplemental fulvic acid on survival, growth performance, digestive ability and immunity of large yellow croaker (Larimichthys crocea) larvae

“…The increased and stable activity of intestinal BBM enzymes such as aminopeptidase and AKP indicates that the gut may fully mature and achieve full function at this stage of development (Kolkovski et al, 2009;Lallès, 2020). The present study found that supplemental FA could significantly improve AKP and LAP activities in the intestinal BBM, which means that FA promote the intestine maturation of larvae (Liu et al, 2020;Xu et al, 2022). Thus, larvae fed diets with FA improved digestive enzyme activity and promoted intestinal development, facilitating adequate digestion and absorption of nutrients in the feed sufficiently.…”

Tragacanth Gum and Linseed Gum as Adhesives Improved the Survival, Digestive Function, Antioxidant Enzyme Activities, and Immunity in Large Yellow Croaker (Larimichthys crocea) Larvae

“…Te improvement of digestive enzyme activities represents the intestinal development and good nutritional status of aquaculture animals [25,26]. Results showed larvae fed with the SA, TG, and LG diets had signifcantly higher activities of trypsin than larvae fed with the PX diet.…”

Astaxanthin: a powerful antioxidant used in aquaculture for coloration with aquatic animal health implications

“…The microalgal cysts are surrounded by a tough sporopollenin or algaenan cell wall which requires either mechanical or chemical processes for astaxanthin extraction. Extraction makes up about 20-to-30% of the production cost of astaxanthin [4,19,40]. The two-step process is the most widely used and is likely the most efficient process because the production of the algal biomass is not ideal under any stress conditions [41].…”

“…distinguishable by the presence of oxygen in addition to a double-bonded polyene carbon chain, whereas carotenes do not have oxygen. Astaxanthin (3,3'-dihydroxy-β, β'carotene-4, 4'dione) is a xanthophyll [19][20][21]. It contains hydroxyl and keto moieties on either side of the ionone ring at either end of the polyene chain which give the molecule both lipophilic and hydrophilic properties.…”

“…It contains hydroxyl and keto moieties on either side of the ionone ring at either end of the polyene chain which give the molecule both lipophilic and hydrophilic properties. It is generally naturally occurring in esterified forms, with many different isomers [2,[19][20][21][22][23][24]. Esterified astaxanthin is found primarily in the skin of fish [25,26], however, most, if not all, astaxanthin found in the muscle of salmonid fish is unesterified or free [27][28][29].…”