Molecules (Aug 2023)

Ethanolic Extract Propolis-Loaded Niosomes Diminish Phospholipase B1, Biofilm Formation, and Intracellular Replication of <i>Cryptococcus neoformans</i> in Macrophages

  • Kritapat Kietrungruang,
  • Sanonthinee Sookkree,
  • Sirikwan Sangboonruang,
  • Natthawat Semakul,
  • Worrapan Poomanee,
  • Kuntida Kitidee,
  • Yingmanee Tragoolpua,
  • Khajornsak Tragoolpua

DOI
https://doi.org/10.3390/molecules28176224
Journal volume & issue
Vol. 28, no. 17
p. 6224

Abstract

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Secretory phospholipase B1 (PLB1) and biofilms act as microbial virulence factors and play an important role in pulmonary cryptococcosis. This study aims to formulate the ethanolic extract of propolis-loaded niosomes (Nio-EEP) and evaluate the biological activities occurring during PLB1 production and biofilm formation of Cryptococcus neoformans. Some physicochemical characterizations of niosomes include a mean diameter of 270 nm in a spherical shape, a zeta-potential of −10.54 ± 1.37 mV, and 88.13 ± 0.01% entrapment efficiency. Nio-EEP can release EEP in a sustained manner and retains consistent physicochemical properties for a month. Nio-EEP has the capability to permeate the cellular membranes of C. neoformans, causing a significant decrease in the mRNA expression level of PLB1. Interestingly, biofilm formation, biofilm thickness, and the expression level of biofilm-related genes (UGD1 and UXS1) were also significantly reduced. Pre-treating with Nio-EEP prior to yeast infection reduced the intracellular replication of C. neoformans in alveolar macrophages by 47%. In conclusion, Nio-EEP mediates as an anti-virulence agent to inhibit PLB1 and biofilm production for preventing fungal colonization on lung epithelial cells and also decreases the intracellular replication of phagocytosed cryptococci. This nano-based EEP delivery might be a potential therapeutic strategy in the prophylaxis and treatment of pulmonary cryptococcosis in the future.

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