The Protective Roles of Dietary Selenium Yeast and Tea Polyphenols on Growth Performance and Ammonia Tolerance of Juvenile Wuchang Bream (Megalobrama amblycephala)

Abstract

In order to investigate protective roles of dietary selenium yeast (SY) and tea polyphenols (TPs) on growth of juvenile Wuchang bream (Megalobrama amblycephala) and its resistance under ammonia stress, juvenile Wuchang bream were randomly assigned into four groups: a control group fed basal diets and three treatment groups fed basal diets supplemented with 0.50 mg/kg SY, 50 mg/kg TPs and a combination of 0.50 mg/kg SY and 50 mg/kg TPs, respectively. After 60 days of feeding, growth parameters of Wuchang bream were measured along with serum hormones and the transcription of growth axis-related genes. Then fish were exposed to ammonia stress of 22.5 mg/L total ammonia nitrogen. Hepatic oxidative damage parameters, antioxidant responses and ultrastructure were evaluated before ammonia exposure (0 h) and at 3, 6, 12, 24, and 48 h after ammonia exposure. Results show that before ammonia exposure, the growth parameters, serum GH and IGF-1 levels as well as the growth axis-related gene expression (gh, ghr2 and igf-1) for the SY and combination groups were higher than those determined for the fish on the control diet. In contrast, the administration of TP alone didn’t have significant effects on the growth parameters and growth-related hormones. After ammonia exposure, compared with the control, remarkable increases in the activity and mRNA expression of hepatic antioxidant enzymes (glutathione peroxidase and catalase superoxide dismutase) in three treatment groups were observed along with decreases of hepatic malondialdehyde and protein carbonylation levels, indicating that the single and combined supplementation of SY and TPs could enhance antioxidant capacity to alleviate oxidative stress and damage by ammonia. Consistent with this finding, alterations of the liver ultrastructure in three treatment groups were less severe and faster recovery than in the control group after ammonia exposure. In conclusion, a basal diet supplemented with the combination of 0.50 mg/kg SY and 50 mg/kg TPs could has very beneficial effects on the whole aspects of the growth and ammonia resistance in Wuchang bream juveniles.

An evaluation on the selenium yeast supplementation in the practical diets of early juvenile sea cucumber ( Apostichopus japonicus ): Growth performance, digestive enzyme activities, immune and antioxidant capacity, and body composition

“…In addition, some studies have found that dietary supplementation of Se‐yeast (0.5mg/kg) could effectively improve nitrite resistance in Wuchang bream ( Megalobrama amblycephala ) (Long et al, 2017) and Chinese mitten crab ( Eriocheir sinensis ) (Wang et al, 2019). Guo et al (2018) found that single and combined supplementation of selenium yeast and green tea‐derived polyphenols improved the antioxidant capacity and immune response in juvenile Wuchang bream under ammonia stress. This finding possible implies the possibility of using Se‐yeast as an additive to enhance the immune response and antioxidant capacity during the summer season when the water temperature is usually at a range of 28℃ to 31℃.…”

“…Insufficient Se intake may cause a high death rate, slow growth rate and reduce feed efficiency of juvenile grouper (Lin & Shiau, 2005). On the opposite, excessive Se intake will impair health and decrease cognitive function in several fish species, including loach ( Paramisgurnus dabryanus ) (Hao et al, 2014), white sturgeon ( Acipenser transmontanus ) (Zee et al, 2016), meagre ( Argyrosomus regius ) (Khalil et al, 2018) and Wuchang bream ( Megalobrama amblycephala ) (Guo et al, 2018).…”

The Gene Regulatory Roles of Herbal Extracts on the Growth, Immune System, and Reproduction of Fish

“…In addition, GH may boost the local synthesis of IGF-1 that exerts paracrine or autocrine effects [ 23 ]. Subsequently, IGF-1 by acting on target cells, causes them to proliferate and differentiate and ultimately stimulates the growth of the body [ 24 ]. The previous studies on the Nile tilapia showed that there is a positive correlation between IGF-1 protein and mRNA levels in liver and body weight gain and SGR of this fish species [ 25 , 26 ].…”

Sub‐chronic exposure to ammonia inhibits the growth of juvenile Wuchang bream (Megalobrama amblycephala) mainly by downregulation of growth hormone/insulin‐like growth factor axis

“…The total RNA obtained by the TRIzol reagent (Takara, Dalian, China) was reversed transcription with PrimeScript™ RT reagent Kit with gDNA Eraser (Takara, Dalian, China) according to our previous study. 37 The detailed test procedures were supplied in Supporting Information (Test S1). The primers sequences of genes were designed by the Primer Premier 5.0 software or referred to previous studies (Table 1).…”