Anti-bacterial exosomes from bee products

19 October 2020

Since ancient times, numerous cultures around the world have been using honeybee-derived products for antimicrobial purposes; this includes honey, royal jelly and bee pollen.

A recent study published by collaborators working in Chile was the first to describe some remarkable anti-bacterial properties of exosome-like vesicles (ELVs) isolated from all three of these honeybee products. Prior to this study, there have been many clinical studies which described the improvement of disease outcome following royal jelly application. These diseases include, but are not limited to mucositis, colitis and infected ulcers.

Antibacterial and biofilm inhibition assays using Staphylococcus aureus, a common bacterial strain involved in wound infection, were performed as part of the current study. These experiments showed that ELVs from honey, bee pollen and royal jelly all inhibit the growth of biofilm in a controlled laboratory setting. These results were confirmed using similar tests, but performed on bacteria in solution as opposed to biofilm. The researchers also showed that honey, bee pollen and royal jelly devoid of exosomes have a decreased antibacterial effect.

Another interesting observation of this research was that ELVs isolated from royal jelly were 10x more potent in inhibiting biofilm growth than their counterparts from honey and bee pollen. The strength of the antibacterial effect was measured on a scale as a ratio of ELVs to bacteria. Strikingly, royal jelly ELVs have shown bactericidal and bacteriostatic effects at ratios of less than 1 vesicle per viable bacterium. One potential explanation for this difference in potency might be the way the vesicle source material itself is generated. Honey and bee pollen are known to contain plant particles, miRNAs and nectar. Royal jelly, on the other hand, is synthesized de novo by nurse bees.

As the investigation showing ELVs presence in bee-derived products as well as their antibacterial effects, this study may pave the way towards a standardized, controlled use of bee-derived products in various medical applications.

As a next step to better understand the difference in functionality between these bee-derived ELVs, analysis of the vesicle cargo would be interesting to evaluate. Since we know these vesicles exist and they are in the same size range as mammalian exosomes, we can apply similar techniques and experimental approaches to further assess these antibacterial properties. Perhaps, we may soon be able to use this naturally occurring material for defined medical applications.

IMAGE "Bee on Flowers" by Jim, the Photographer is licensed under CC BY 2.0