Quercetin Improving Lipid Metabolism by Regulating Lipid Metabolism Pathway of Ileum Mucosa in Broilers
Mi Wang, Yanjun Mao, Bo Wang, Shanshan Wang, Lu Han, Linlin Ying, Yao Li
Abstract
This study is aimed at evaluating the regulatory mechanism of quercetin on lipid metabolism in the ileum of broilers to better understand these pathways decreasing abdominal fat. 480 chickens were randomly divided into 4 groups (control, 0.02% quercetin, 0.04% quercetin, and 0.06% quercetin). Breast muscle, thigh muscle, and abdominal fat pad were removed and weighed at 42 d of age. Serum was obtained by centrifuging blood samples from the jugular vein (10 ml) to determine high-density lipoprotein (HDL), total cholesterol (TC), low-density lipoprotein (LDL), triglyceride (TG), leptin, and adiponectin using ELISA. About 5 g of the ileum was harvested and immediately frozen in liquid nitrogen for RNA-seq. Then, the confirmation of RNA-seq results by the Real-Time Quantitative PCR (RT-qPCR) method was evaluated using Pearson’s correlation. Compared with control, abdominal fat percentage was significantly decreased with increasing quercetin supplementation, and the best result was obtained at 0.06% dietary quercetin supplementation (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.01</mml:mn></mml:math>). Breast muscle percentage was significantly decreased at 0.02% quercetin (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.01</mml:mn></mml:math>), and thigh muscle percentage tended to increase (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn>0.078</mml:mn></mml:math>). Meanwhile, 0.04% and 0.06% quercetin significantly decreased TG (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.01</mml:mn></mml:math>), TC (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.01</mml:mn></mml:math>), and LDL content (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.05</mml:mn></mml:math>) in serum. Serum leptin and adiponectin contents were significantly increased by 0.04% and 0.06% dietary quercetin supplementation, compared with the control (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.01</mml:mn></mml:math>). Analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database were used to identify differently expressed genes and lipid metabolism pathways. Quercetin decreased abdominal fat percentage through regulating fat digestion and absorption, glycerophospholipid metabolism, AMPK signaling pathway, fatty acid degradation, and cholesterol metabolism.