Assessing the role of Berberine as an inhibitor of advanced glycation end products (AGEs) formation using in vitro and molecular interaction studies.

Abstract

Glycation and aggregation of proteins have garnered more interest in recent years. Glycation leads to the formation of protein aggregates and advanced glycation ends (AGEs) that play crucial roles within several pathological conditions. The objective of our study is to gain a deeper understanding of the formation of AGEs and aggregates of human serum albumin (HSA) in the presence of methylglyoxal and the protective effects of the phytochemical berberine. HSA was incubated with methylglyoxal and different concentrations of berberine for 7-14 days at 35-37 °C. Methylglyoxal resulted in the formation of AGEs, fibrillar aggregates, and hydrophobic protein patches in HSA, as was evident from AGE fluorescence, ThT and ANS fluorescence studies. It also disrupted the secondary structure of HSA shown by CD spectroscopy. All these parameters were restored towards native HSA in the glycated HSA + berberine samples. Molecular docking was employed to identify the critical HSA residues implicated in the HSA-berberine interaction and also to determine the spontaneous binding of berberine on the HSA sub-domain favoring the thermodynamic binding. The binding energy between HSA-berberine was found to be -9.1 kcal/mol. Various types of forces like hydrophobic interactions, polar forces, hydrogen bonds, etc are were at play between the HSA and berberine interaction. Since MGO level is increased in pathological conditions such as type II diabetes, there is a chance that increased MGO concentration could cause glycation of HSA, leading to decreased levels of HSA, as observed in pathological circumstances. The binding of berberine to lysine and arginine residues might be linked to its antiglycation potential as these amino acids play an important role in the glycation of proteins. Nevertheless, additional inquiries are needed to substantiate this claim. Thus, our study characterizes AGEs and aggregates of clinically important protein HSA.