The role of vitamin E in polyunsaturated fatty acid synthesis and alleviating endoplasmic reticulum stress in sub-adult grass carp (Ctenopharyngodon idella)

Ke Yao; Lin Feng; Wei-Dan Jiang; Yang Liu; Lu Zhang; Hai-Feng Mi; Xiao-Qiu Zhou; Pei Wu

doi:10.1016/j.aninu.2023.09.008

The role of vitamin E in polyunsaturated fatty acid synthesis and alleviating endoplasmic reticulum stress in sub-adult grass carp (Ctenopharyngodon idella)

Anim Nutr. 2023 Dec 2:16:275-287. doi: 10.1016/j.aninu.2023.09.008. eCollection 2024 Mar.

Authors

Ke Yao¹, Lin Feng^{1

2

3}, Wei-Dan Jiang^{1

2

3}, Yang Liu^{1

2

3}, Lu Zhang^{4

5}, Hai-Feng Mi^{4

5}, Xiao-Qiu Zhou^{1

2

3}, Pei Wu^{1

2

3}

Affiliations

¹ Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, China.
² Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 611130, China.
³ Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Ministry of Agriculture and Rural Affairs, Key Laboratory of Sichuan Province, Chengdu, 611130, China.
⁴ Tongwei Co., Ltd., Chengdu, 610041, China.
⁵ Healthy Aquaculture Key Laboratory of Sichuan Province, Chengdu, 610041, China.

Abstract

Vitamin E (VE) is an essential lipid-soluble vitamin that improves the fish flesh quality. However, the underlying molecular mechanisms remain unclear. This study aimed to investigate the effects of VE on growth performance and flesh quality in sub-adult grass carp (Ctenopharyngodon idella). A total of 450 fish (713.53 ± 1.50 g) were randomly divided into six treatment groups (three replicates per treatment) and fed for nine weeks with different experimental diets (dietary lipid 47.8 g/kg) that contained different levels of VE (5.44, 52.07, 96.85, 141.71, 185.66, and 230.12 mg/kg diet, supplemented as dl-α-tocopherol acetate). Notably, the treatment groups that were fed with dietary VE ranging from 52.07 to 230.12 mg/kg diet showed improvement in the percent weight gain, special growth rate, and feed efficiency of grass carp. Moreover, the treatment groups supplemented with dietary VE level of 141.71, 185.66, and 230.12 mg/kg diet showed enhancement in crude protein, lipid, and α-tocopherol contents in the muscle, and the dietary levels of VE ranging from 52.07 to 141.71 mg/kg diet improved muscle pH_24h and shear force but reduced muscle cooking loss in grass carp. Furthermore, appropriate levels of VE (52.07 to 96.85 mg/kg diet) increased the muscle polyunsaturated fatty acid content in grass carp. Dietary VE also increased the mRNA levels of fatty acid synthesis-related genes, including fas, scd-1, fad, elovl, srebp1, pparγ, and lxrα, and up-regulated the expression of SREBP-1 protein. However, dietary VE decreased the expression of fatty acid decomposition-related genes, including hsl, cpt1, acox1, and pparα, and endoplasmic reticulum stress-related genes, including perk, ire1, atf6, eif2α, atf4, xbp1, chop, and grp78, and down-regulated the expression of p-PERK, p-IRE1, ATF6, and GRP78 proteins. In conclusion, dietary VE increased muscle fatty acid synthesis, which may be partly associated with the alleviation of endoplasmic reticulum stress, and ultimately improves fish flesh quality. Moreover, the VE requirements for sub-adult grass carp (713.53 to 1590.40 g) were estimated to be 124.9 and 122.73 mg/kg diet based on percentage weight gain and muscle shear force, respectively.

Keywords: Endoplasmic reticulum stress; Flesh quality; Grass carp; Growth performance; Muscle polyunsaturated fatty acid level; Vitamin E.