In Silico Analysis of novel Phytocompounds targetting Dipeptidyl peptidase 4 Enzyme: A New Link between Prediabetes and its cardio-metabolic complications

Abstract

Background

DPP-4 inhibitors, are widely used clinically for treatment of Diabetes. Increase in circulating DPP4 levels have been well demonstrated in patients with Type 2 Diabetes mellitus. The present study assessed the contribution of DPP-4 axis to the pathophysiology of Prediabetes and its cardiometabolic complications. In addition, in silico analysis of phytocompounds that target DPP 4 enzyme was undertaken to identify novel Phytocompounds with therapeutic potential in Prediabetes.

Methodology

A novel experimental model of Prediabetes coexisting with hypertension and dyslipidemia was developed in experimental rats to elucidate the pathophysiological role of DPP-4 in Prediabetes and its resultant cardio-metabolic sequale. In the Prediabetic rats, DPP-4 levels, lipid profile, blood pressure readings, fasting blood sugar values, insulin resistance, beta cell function were measured and compared to Normal Control group. In addition, the DPP-4 Inhibitory activity of Phytocompounds (Arjunetin, Guggulsterone) was studied by molecular docking studies including Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), DPP 4 binding affinity and Protein-ligand simulation between the DPP4 and the Phytocompounds was performed. Results were compared to Vildagliptin, the synthetic DPP-4 inhibitor and metformin (Glucophage), the standard antidiabetic drug used in clinical settings.

Results

A statistically significant increase (p < 0.001) in DPP-4 levels along with a decline in bea cell function with increase in Insulin resistance was observed in Prediabetic rats. A positive correlation (p < 0.001) between serum DPP-4 with HbA1c, lipids, and systolic blood pressure was found. The novel model of Prediabetes co-existing with hypertension and dyslipidemia was successfully developed and validated. The silico active site interaction data from simulation studies demonstrated that Arjunetin and Guggulsterone shows effective and stable binding with DPP-4. Arjunetin maintains its contact with Glu205, Glu206, and Asn710 and by interacting with Val207 and His740, it effectively occupies the flanking residues of the active site area. Based on their protein-ligand contact report, Vildagliptin maintains its connection through Tyr547 and during simulation, Guggulsterone interacts with Ser630.

Conclusion

The current study offers experimental evidence of DPP-4′s causal role in the development of cardio-metabolic consequences (dyslipidemia and hypertension) of Prediabetes. Arjunetin and Guggulsterone are two Phytocompounds whose potential as promising DPP-4 inhibitors has been further documented using in silico molecular docking studies.