Diosgenin-induced physicochemical effects on phospholipid membranes

• Main Authors: Ondevilla, Joan Candice V., Mukogawa, Akane, Hanashima, Shinya, Umegawa, Yuichi, Murata, Michio
• Format: text
• Published: Animo Repository 2021
• Subjects: Diosgenin—Physiological effect; Dioscoreaceae —Analysis; Membrane lipids; Biochemistry
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/11548
• Institution: De La Salle University

Diosgenin (DGN), a plant sterol found in the family Dioscorea, attracts increasing attention for its various pharmacological activities. With the use of fluorescence and ssNMR spectroscopy, we examined the steroidal structural effect of the sterol on the physicochemical properties of phospholipid bilayer membranes consisting of palmitoyloleoylphosphatidylcholine (POPC) and comparing it to a widely studied steroidal sterol, cholesterol (Cho). In diphenylhexatriene (DPH) anisotropy experiment, DGN up to 30 mol% stably bound to the POPC bilayer and induced a similar ordering effect on POPC to Cho. Measurement of membrane hydration using laurdan also revealed a similar tendency for Cho and DGN. These results suggest that DGN below 30 mol% has comparable effects with Cho on basic biomembrane properties. However, in 2H NMR, using a deuterated phospholipid, 10-d2-POPC, revealed slight differences in the ordering effect in POPC bilayer in which DGN somewhat affects the lipid packing. These spectra also show that DGN is oriented parallel to the membrane normal like Cho. 31P NMR of POPC in bilayers revealed that, unlike Cho, DGN altered the interactions of POPC headgroups at higher contents over 30 mol%.