Interfacial and Molecular Mechanisms of Pancreatic Lipase Modulation by Saponin-Rich Extracts with Antioxidant...

Pancreatic lipase activity depends strongly on interfacial conditions created by bile salts, motivating the search for plant-derived surfactants that may modulate lipid digestion. In our previous work, ginseng root and horse chestnut seed extracts were identified as potent stimulators of pancreatic lipase. Here, we expanded this investigation to additional Panax and Aesculus species and to saponin-rich extracts from Acer pseudoplatanus, Herniaria glabra, and Polypodium vulgare. Extracts were evaluated for effects on pancreatin lipolysis in relation to equilibrium surface tension, surface rheology, and olive-oil emulsion stability. Antiradical and antioxidant activities, total phenolic content, and flavonoid content were also determined. White ginseng root extract (Panax ginseng) produced the strongest stimulation, followed by horse chestnut seed extract (Aesculus hippocastanum), whereas Aesculus marylandica seed peel extract inhibited lipase activity. Several extracts showed concentration-dependent switching from weak inhibition to stimulation. Antioxidant and antiradical activities correlated strongly with total phenolic content, while emulsion stabilization did not correlate with lipase stimulation. Molecular modeling showed that cholate, escinescin Ia, osladin, and ginsenoside Rg1 did not persistently occlude the catalytic pocket, whereas several other saponins showed active-site blocking. Together, the results support a mechanism in which saponin-rich extracts regulate lipolysis through combined interfacial effects and compound-specific enzyme interactions.