Effects of dietary supplementation with quercetagetin on nutrient digestibility, intestinal morphology, immunity, and antioxidant capacity of broilers

Abstract

Quercetagetin (QG) is gaining increased attention as a potential alternative to in-feed antioxidants due to its antioxidant activity. This experiment was conducted to investigate the effects of dietary supplementation with QG on nutrient digestibility, intestinal morphology, immunity, and antioxidant capacity of broilers. Four hundred 1-day-old Ross 308 broilers were randomly assigned into 4 groups with 10 replicates in each group and 10 broilers in each replicate. The four dietary treatments included the basal diet supplemented with 0, 3.2, 4.8, or 6.4 mg/kg QG. The results showed that dietary supplementation with QG significantly promoted the broilers' apparent digestibility of phosphorus (P < 0.05), increased the villus height in jejunum and ileum, and reduced the crypt depth in jejunum and ileum, which significantly increased the ratio of villus height to crypt depth in the jejunum and ileum (P < 0.05). The dietary supplementation with QG also significantly enhanced the immunoglobulin G (IgG) and complement 4 (C4) levels in the blood (P < 0.05), the activity of total antioxidant capacity (T-AOC) in serum, jejunum mucosa, and ileum mucosa, the activity of superoxide dismutase (SOD) in the serum and liver (P < 0.05), and significantly up-regulated the kelch-like ECH-associated protein 1 (Keap1), nuclear factor E2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO-1), glutathione peroxidase (GSH-Px) and superoxide dismutase 1 (SOD1) mRNA expression levels in the jejunum mucosa, ileum mucosa, and liver tissues of broilers. Therefore, supplementing broilers' diets with QG can enhance the apparent digestibility of phosphorus, improve the structure and morphology of jejunum and ileum, promote immunity, and increase the activity of antioxidant enzymes and the antioxidantive capacity through the Nrf2/antioxidant response element (ARE) signaling pathway mediated by Keap1.

Quercetagetin alleviates zearalenone-induced liver injury in rabbits through Keap1/Nrf2/ARE signaling pathway

“…In this study, there were no significant differences in ADG, ADFI, F/G, and the liver, kidney, and spleen organ indexes among the rabbits across the three groups, implying that the dosage and time of ZEN and QG administration had no significant effect on the growth performance of rabbits, including their liver, kidney, and spleen development. This is partially consistent with a previous report where QG (3.2, 4.8, or 6.4 mg/kg, fed for 42 days) had no significant effect on the spleen, thymus, and bursa of fabricius organ indexes in broilers ( Wu et al, 2022b ). ZEN effects on growth performance are related to dosage, exposure time, animal species, growth stage, and other factors ( Gajęcka et al, 2016 ; Chen et al, 2019 ; Liu et al, 2020 ; Ropejko and Twarużek, 2021 ).…”

“…Notably, QG (6.4 mg/kg, fed for 42 days) significantly increased the blood GSH-Px activity and the liver GSH-Px, and SOD activities in broilers. At the same time, QG significantly reduces the MDA level, which is partially consistent with the results in this study ( Wu et al, 2022b ). Besides, QG supplementation significantly reduced the abundance of Keap1 mRNA in the liver of rabbits in the ZEN + QG group compared to the ZEN group.…”

“…On the one hand, oxidative stress is an important pathway for ZEN to induce hepatotoxicity ( Tatay et al, 2017 ). Besides, QG not only has a strong capacity to scavenge DPPH, ABTS, ·OH and other free radicals ( Fuentes et al, 2021 ) but also enhances the antioxidant capacity in the liver through the Nrf2/ARE signaling pathway ( Wu et al, 2022b ). Therefore, in this study, supplementing the diet with QG alleviated the oxidative damage to the liver of rabbits in the ZEN + QG group.…”

“…It is a polyhydroxyphenol compound with hydrogen donor substituents on the benzene ring, which have a strong capacity to scavenge 2,2-biphenyl-1-picrylhydrazinyl (DPPH), hydroxyl radicals (·OH), 2,2′-diazobis (3-ethylbenzothiazoline-6-sulfonic acid) diamine salt (ABTS) and other free radicals, thereby serving as a natural antioxidant ( Fuentes et al, 2021 ). QG increases the antioxidant enzymatic activities in the liver, ileum, and jejunum of broilers and reduces the level of malondialdehyde (MDA) through the nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signal pathway mediated by Kelch-like ECH-associated protein 1 (Keap1) to improve the broiler antioxidant performance, intestinal structure, and morphology, and promote the nutrient digestibility ( Wu et al, 2022b ). QG also has immunomodulatory and anti-inflammatory effects.…”

Effects of Dietary Terminalia chebula Extract on Growth Performance, Immune Function, Antioxidant Capacity, and Intestinal Health of Broilers

“…However, previous research has demonstrated that active components of TCE, such as flavonoids and phenolic acids, may boost Ig levels and improve animal immune function [ 43 , 73 ]. Dietary quercetagetin increased blood IgG levels, according to Wu et al [ 74 ], who identified the flavonol compound chemically. The levels of IgM and IgA in serum were higher in broiler chickens fed diets supplemented with 1 or 2 g/kg Acanthopanax polysaccharides, according to Long et al [ 75 ].…”