HPLC-DAD-MS Characterization, Antioxidant Activity, -amylase Inhibition, Molecular Docking, and ADMET of Flavonoids from Fenugreek Seeds

Fenugreek (Trigonella foenum-graecum) has a great beneficial health effect; it has been used in traditional medicine by many cultures. Likewise, the alpha-amylase inhibitors are potential compounds in the development of drugs for the treatment of diabetes. The beneficial health effects of fenugreek lead us to explore the chemical composition of the seeds and their antioxidant and alpha-amylase inhibition activities. The flavonoid extraction from fenugreek seeds was achieved with methanol through a Soxhlet apparatus. Then, the flavonoid glycosides were characterized using HPLC-DAD-ESI-MS analysis. The antioxidant capacity of fenugreek seed was measured using DPPH, FRAP, ABTS, and CUPRAC assays. Finally, the alpha-amylase inhibition activity was carried out using in vitro and in silico methods. The methanolic extract was found to contain high amounts of total phenolics (154.68 +/- 1.50 mu g GAE/mg E), flavonoids (37.69 +/- 0.73 mu g QE/mg E). The highest radical-scavenging ability was recorded for the methanolic extract against DPPH (IC50 = 556.6 +/- 9.87 mu g/mL), ABTS (IC50 = 593.62 +/- 9.35 mu g/mL). The ME had the best reducing power according to the CUPRAC (A 0.5 = 451.90 +/- 9.07 mu g/mL). The results indicate that the methanolic extracts of fenugreek seed best alpha-amylase inhibition activities IC50 = 653.52 +/- 3.24 mu g/mL. Twenty-seven flavonoids were detected, and all studied flavonoids selected have good affinity and stabilize very well in the pocket of alpha-amylase. The interactions between the studied flavonoids with alpha-amylase were investigated. The flavonoids from fenugreek seed present a good inhibitory effect against alpha-amylase, which is beneficial for the prevention of diabetes and its complications.