Atomic Insights Into Self-Assembly of Zingibroside R1 and its Therapeutic Action Against Fungal Diseases

Abstract

Natural products are a crucial resource for drug discovery, but poor understanding of the molecular-scale mechanisms of their self-assembly into soluble, bioavailable hydrogels limits their applications and therapeutic potential. It is demonstrated that Zingibroside R1 (ZR1), derived from Panax notoginseng, undergoes spontaneous self-assemble into a hydrogel comprising helical nanofibrils with potent antifungal activity lacking in its monomeric state. Cryogenic electron microscopy (cryo-EM) revealed an intricate hydrogen-bonding network that facilitates ZR1 nanofibril formation, characterized by a hydrophobic core and hydrophilic exterior architecture, which underpin its binding activity with cell wall in the vulvovaginal candidiasis (VVC) pathogen, C. albicans. The hydrogen-bonding interface between ZR1 gel and glucan compromises membrane integrity, inhibiting C. albicans proliferation in vitro and in VVC model mice in vivo. ZR1 gel could also deliver probiotic Lactobacillus, synergistically inhibiting VVC and restoring the vaginal microenvironment. This study advances the mechanistic understanding of ZR1's structure-function relationships, offering valuable insights into the rational design and therapeutic optimization of natural product-based hydrogels.

Keywords: antifungal; cryo‐EM; natural products; self‐assembly; vulvovaginal candidiasis.