Quercetin Attenuates Oxidative Stress and Immune Inflammation via Modulating Heme and ROS Pathways in Rats Fed...

Area of Science:

• Animal Nutrition and Toxicology
• Biochemistry and Molecular Biology
• Immunology

Background:

• Dietary protein oxidation negatively impacts animal health, with limited effective interventions.
• Oxidized soybean meal (OS) poses a significant risk due to induced oxidative stress and inflammation.
• Quercetin (Q) is a flavonoid with potential antioxidant and anti-inflammatory properties.

Purpose of the Study:

• To investigate the protective effects of quercetin (Q) supplementation against oxidative stress and inflammatory injury induced by protein-oxidized soybean meal (OS) in rats.
• To elucidate the molecular mechanisms underlying Q's protective effects, focusing on antioxidant status, inflammatory markers, and transcriptomic pathways.
• To evaluate the impact of OS and Q supplementation on serum biochemistry, intestinal, and hepatic histology.

Main Methods:

• A 2x2 factorial experiment using 48 Sprague-Dawley rats fed fresh soybean meal (FS) or OS, with or without 400 mg/kg Q for 28 days.
• Analysis of serum biochemistry, intestinal and hepatic histology, antioxidant capacity (T-AOC, GSH-Px, GSH), inflammatory markers (IgG, IL-6), and reactive oxygen species (ROS, MDA).
• Transcriptomic analysis to identify affected pathways in the jejunum and liver, followed by validation of key gene and protein expression.

Main Results:

• OS feeding increased serum glucose and urea nitrogen, caused duodenal, jejunal, and hepatic lesions, and elevated oxidative stress markers (ROS, MDA).
• OS increased inflammatory markers (IgG, IL-6) and downregulated antioxidant capacity (T-AOC, GSH-Px, GSH).
• Q supplementation reversed these adverse effects, improving antioxidant status, reducing inflammation and tissue damage, and downregulating upregulated heme and ROS synthesis pathways.

Conclusions:

• Quercetin (Q) effectively alleviates oxidative stress, inflammation, and tissue damage induced by oxidized soybean meal (OS) in rats.
• Q exerts its protective effects by modulating heme biosynthesis and reactive oxygen species (ROS) synthesis pathways.
• Q normalizes the expression of key genes and proteins involved in inflammatory and oxidative stress responses in the jejunum and liver.