Effects of dietary tea polyphenols on growth, immunity and lipid metabolism of juvenile black carpMylopharyngodon piceus

Abstract

An 8‐week feeding experiment was aimed to investigate the effect of dietary tea polyphenols (TP) on growth, immunity and lipid metabolism in juvenile black carp Mylopharyngodon piceus (initial weight 5.90 ± 0.03 g). Tea polyphenols were added at different levels (0, 25, 50, 100 and 500 mg/kg; TP0, TP25, TP50, TP100 and TP500). The results are as follows: the highest specific growth rate (SGR) and condition factor (CF) and activity of trypsin (TRS) of intestine in TP50, but SGR and activities of lipase (LPS)and TRS of intestine and content of whole body crude protein in TP500 were remarkably lower than TP0. Compared with TP0, content of serum superoxide dismutase (SOD) and glutamic oxalacetic transaminase (GOT) remarkably increased (p < .05), but contents of glutathione (GSH), glutathione peroxidase (GSH‐Pox), malondialdehyde (MDA), triglyceride (TG) and low‐density lipoprotein cholesterol (LDL‐C) were significantly decreased (p < .05), content of cortisol was remarkably lower in TP50 and TP100 (p < .05), expression of growth hormone (GH) and melanocortin 4 receptor (MC4R) in liver and GH in muscle were remarkably up‐regulated in TP50, but expression of apolipoprotein A‐1 (ApoA1), GH and MC4R of intestine, ApoA1 of liver and MC4R of muscle in TP500 were remarkably down‐regulated, contents of complement 3 (C3), complement 4 (C4), high‐density lipoprotein cholesterol (HDL‐C) and LDL‐C were significantly reduced in TP500 (p < .05). In conclusion, TP could improve growth performance and oxidative capacity on juvenile black carp, and its optimal dosage was 50 mg/kg.

Hypolipidemic, anti‐inflammatory, and anti‐atherosclerotic effects of tea before and after microbial fermentation

“…Pu‐erh tea effectively lowers lipids, as evidenced by epidemiology, in vitro experiments, and clinical investigation (Huang et al., 2019; Sun et al., 2019). Furthermore, theabrownins, tea polysaccharides, tea polyphenols, GA, caffeine, and lovastatin can lower lipids (Gong et al., 2010; Nakamura et al., 2017; Sugiura et al., 2020; Xiong, Cao et al., 2019; Zeng et al., 2019; Zhong et al., 2020). In this study, sun‐dried green tea was inoculated with Monascus purpureus and fermented to obtain fermented pu‐erh tea.…”

Immunomodulatory Effects of Green Tea Polyphenols

“…GTPs have a special structure of polycyclic aromatic hydrocarbons, which can reduce oxidative free radicals and prevent critical cellular components from being oxidized [ 80 ]. Based on research in nutritional immunology, dietary GTPs are effective in meliorating immune related diseases through attenuating oxidative stress [ 36 ].…”

“…In piglets subjected to oxidative stress, dietary GTPs could promote proliferation and activation of T lymphocytes, elevate the ratio of CD4+/CD8+, attenuate the level of pro-inflammatory IL-1, decrease the concentration of serum IFN- γ , enhance serum concentrations of anti-inflammatory cytokine IL-4, lead the immune shift from Th1 to Th2, and alleviate growth depression, which showed significantly immunomodulatory potentials [ 36 ]. In juvenile black carp Mylopharyngodon piceus , GTPs (25-500 mg/kg) remarkably increased the content of serum superoxide dismutase (SOD) and glutamic oxalacetic transaminase (GOT), but decreased the contents of glutathione (GSH), glutathione peroxidase (GSH-Pox), malondialdehyde (MDA), cortisol, triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) at significant level (p <0.05) [ 80 ]. GTPs could effectively improve the growth performance and oxidative capacity on juvenile black carp with the optimal dosage of 50 mg/kg [ 80 ].…”

“…In juvenile black carp Mylopharyngodon piceus , GTPs (25-500 mg/kg) remarkably increased the content of serum superoxide dismutase (SOD) and glutamic oxalacetic transaminase (GOT), but decreased the contents of glutathione (GSH), glutathione peroxidase (GSH-Pox), malondialdehyde (MDA), cortisol, triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) at significant level (p <0.05) [ 80 ]. GTPs could effectively improve the growth performance and oxidative capacity on juvenile black carp with the optimal dosage of 50 mg/kg [ 80 ]. In healthy Wuchang bream juveniles, dietary GTPs have elevated the total antioxidant capacity through increasing contents of catalase and glutathione peroxidase in serum before and after ammonia exposure and reduce serum cortisol level [ 55 ].…”

“…GTPs reduced the contents of triacylglycerol, total cholesterol, and low-density lipoprotein cholesterol, as well as inhibited body andhepatic fat accumulation [ 107 , 108 ]. In juvenile black carp Mylopharyngodon piceus , GTPs (500 mg/kg) significantly reduced the HDL-C and LDL-C [ 80 ]. EGCG could limit lipid absorption and even lower plasma lipid levels in rats [ 109 ].…”