Antifungal and antibiofilm activities of bee venom loaded on chitosan nanoparticles: a novel approach for combating fungal human pathogens

Abstract

The prevalence of opportunistic human fungal pathogens is increasing worldwide, and antimicrobial resistance is one of the greatest medical challenges the world faces. Therefore, this study aimed to develop a novel agent to control fungal pathogens. The honeybee products (honey, royal jelly, propolis, bee bread, and bee venom) were screened against unicellular fungal (UCF) pathogens (Cryptococcus neoformans, Kodamaea ohmeri, and Candida albicans) and the bee venom was only exhibited an inhibitory effect against them. The protein contents of crude bee venom were separated using the gel filtration technique into eight fractions which were visualized on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to confirm the presence of five bands with molecular weights of 65, 43, 21, 15, and 3 KDa. Bee venom (BV) of Apis mellifera loaded chitosan nanoparticles were prepared by the ionotropic gelation method. The encapsulation efficiency%, average size, zeta potentials, and surface appearance by Transmission electron microscope (TEM) were evaluated for the prepared nanoparticles. The minimum inhibitory concentration (MIC) of crude BV and BV loaded chitosan nanoparticles (BV-CNPs) was evaluated against the offer mentioned UCF where the MIC values of crude BV were 6.25, 3.12 & 6.25 while MIC values in the case of BV-CNPs were decreased to 3.12, 3.12 & 1.56 mg/ml against C. neoformans, K. ohmeri and C. albicans, respectively. Also, the results showed that BV-CNPs suppressed the biofilm formation as well as yeast to hyphal transition formed by the examined UCF. These results revealed that BV-CNPs are a promising natural compound for fungal pathogens treatment.

Keywords: Bee venom-loaded chitosan nanoparticles; Biofilm formation; Candida albicans; Cryptococcus neoformans; Kodamaea ohmeri; Yeast-hyphae transition.

Fig. 1

Antifungal activity of bee products against C. albicans ATCC 90023, K. ohmeri, and C. neoformans. 1: bee venom, 2: honey, 3: propolis, 4: bee bread, 5: Royal jelly, 6: DMSO and C: fluconazole

Fig. 2

A typical elution profile for the chromatography of crude bee venom on Sephacryl 100 column previously equilibrated with phosphate buffer pH 7.2. The elution was performed using phosphate buffer pH 7.2 containing 0.15 M NaCl at flow rate 0.5 ml/fraction and absorbance recorded at 280

Fig. 3

13.5% SDS–PAGE of bee venom after fractionation by Sephacryl 100 column. Lane Mr is molecular mass markers, lane 1 is crude bee venom, and lanes 2–9 are the eluted fractions respectively. The total protein profile of fractions was analyzed by SDS–PAGE and stained with Coomassie Brilliant Blue

Fig. 4

Size distribution by % number of A free chitosan nanoparticles and B bee venom-loaded chitosan nanoparticles (BV-CNPs)

Fig. 5

Zeta potential of A free chitosan nanoparticles and B bee venom-loaded chitosan nanoparticles (BV-CNPs)

Fig. 6

Transmission electron micrographs of A free chitosan nanoparticles and B BV-CNPs

Fig. 7

Antibiofilm activity of BV-CNPs

Fig. 8

Inhibition of hyphal transition in spider media using different concentrations of BV-CNPs under the inverted microscope (Magnification power = ×100)