Molecular Mechanism of Lotus Seedpod Oligomeric Procyanidins Inhibiting the Absorption of Oligopeptide-Advanced Glycation End Products

Abstract

Research on advanced glycation end product (AGEs) inhibition has generally focused on food processing, but many protein-AGEs will still be taken. Oligopeptide (OLP)-AGEs, as the main form after digestion, will damage human health once absorbed. Here, we investigated the ability of lotus seedpod oligomeric procyanidins (LSOPC) to inhibit the absorption of the OLP-AGEs and elucidated the underlying mechanism. Our results showed that the inhibition rate of LSOPC on the absorption of OLP-AGEs was about 50 ± 5.38%. 0.1, 0.2, and 0.3 mg/mL could upregulate the expression of ZO-1 and downregulate the expression of PepT1 and clathrin. Molecular docking showed that LSOPC could compete with the binding of OLP-AGEs to PepT1 and AP-2, thus inhibiting the absorption of OLP-AGEs. Furthermore, the interaction of LSOPC with the OLP-AGEs reduced the surface hydrophobicity of OLP-AGEs. It altered the secondary structure of the OLP-AGEs, thus weakening the affinity of the OLP-AGEs to the transporter protein to inhibit the absorption of OLP-AGEs. Together, our data revealed potential mechanisms by which LSOPC inhibit the absorption of OLP-AGEs and opened up new perspectives on the application of LSOPC in reducing the increasing health risks posed by OLP-AGEs.

Pulsed Electric Field Combined with Deep Eutectic Solvents Enhanced the Antiglycation Activity of Noni Flavonoid Extracts by Directionally Regulating Their Glycoside and Aglycone Proportions

“…In the nonenzymatic glycation process, the side chains of amino acid residues with –NH and –NH 2 in proteins are susceptible to oxidative attack, leading to the formation of carbonyl derivatives . The increased tendency for protein aggregation was also directly linked to the oxidative damage caused by glycation. ,, The BSA structure in the NF4-treated sample was closer to that of native BSA based on the comprehensive evaluation of the changes of SH, carbonyl, cross-β linking, and secondary structures, indicating that the ability of NF0 to protect protein structures was significantly enhanced after its flavonoid composition regulated by PEF combined with Ch/Oxa. Generally, the structural features and nature of substitutions on benzene rings are closely related to the antioxidant activity of flavonoids .…”

“…However, excessive protein glycation in the human body increases the risk of chronic diseases . High blood sugar caused by a long-term high-energy diet promotes the nonenzymatic glycation of proteins in the human body, resulting in the formation of Amadori products, which can be subsequently transformed into advanced glycation end products (AGEs) through rearrangement. , The accumulation of AGEs has been proven to be closely related to diabetes-associated complications such as nephropathy, atherosclerosis, and retinopathy . Dicarbonyl compounds, crucial intermediates in the conversion of amadori products to AGEs, including glyoxal, methylglyoxal (MGO), and 3-deoxyglucosone, can induce protein aggregation by binding with amino acid residues, facilitating pathological reactions in the tissues and organs .…”