Kaempferol inhibits the activity of pancreatic lipase and its synergistic effect with orlistat

Abstract

Kaempferol can inhibit the activity of pancreatic lipase relevant to obesity. • Kaempferol was a competitive inhibitor of Pancreatic lipase (PL). • Kaempferol induced the conformational changes of PL. • Kaempferol bound to the active center of PL. • The combination of kaempferol and orlistat showed a synergitic inhibition effect on PL. Repression of pancreatic lipase activity reduces the excessive absorption of lipids, thereby reducing the risk of being overweight and obese. In the study, the inhibition of kaempferol on pancreatic lipase was studied by various spectroscopy techniques and molecular docking analysis. Kinetic analysis indicated that kaempferol reversibly inhibited pancreatic lipase activity in a competitive manner and showed the synergistic inhibition with orlistat. The fluorescence titrations suggested that kaempferol quenched the fluorescence of pancreatic lipase and the binding process was mainly driven by hydrophobic interactions and hydrogen bonds. The structural compactness of pancreatic lipase was verified by the results of circular dichroism and Fourier transform infrared spectra. Molecular docking and molecular dynamics simulation showed that kaempferol interacted with the residues Lys42 and Tyr404 in the active site of the enzyme by hydrogen bonds, preventing the substrate from binding to the active site. These findings may provide a theoretical basis for the further study of kaempferol as a natural anti-obesity supplement.