Soluble Fraction from Lysates of Selected Probiotic Strains Differently Influences Re-Epithelialization of HaCaT Scratched Monolayer through a Mechanism Involving Nitric Oxide Synthase 2.

Francesca Lombardi,Paola Palumbo,Francesca Rosaria Augello,Maria Grazia Cifone,Maurizio Giuliani,Antonella Mattei,Benedetta Cinque

doi:10.3390/biom9120756

Abstract

A growing body of evidence supports the use of probiotics in the treatment of several skin conditions, including wounds. Even if in vitro and in vivo studies have highlighted the pro-healing effects of some probiotic bacteria, the underlying mechanisms are still not fully defined. The current investigation aimed to determine the re-epithelialization potential of the soluble fraction from lysate of seven different probiotic strains belonging to different genera (i.e., Streptococcus, Lactobacillus, and Bifidobacterium) on in vitro physically wounded HaCaT monolayer model. The results suggested that the soluble fraction of S. thermophilus, L. plantarum, and L. acidophilus promoted the re-epithelialization of scratched HaCaT monolayers, whereas those from B. longum, B. infantis, and B. breve significantly inhibited the process. On the other hand, L. bulgaricus showed no significant effect on in vitro wound repair. The mechanisms underlying the pro- or anti-healing properties of selected bacterial strains strictly and positively correlated with their ability to modulate nitric oxide synthase 2 (NOS2) expression and activity. Accordingly, the pre-treatment with aminoguanidine (AG), a specific inhibitor of NOS2 activity, abrogated the pro-healing effects of S. thermophilus, L. plantarum, and L. acidophilus.

Highlights

According to the Food and Agriculture Organisation of the United Nations (FAO) and the WorldHealth Organisation (WHO), probiotics are defined as live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host [1,2]
Given the crucial role played by nitric oxide synthase 2 (NOS2)/nitric oxide (NO) system in the wound repair process, in the present study, after comparing the ability of the soluble fraction from lysates of seven different probiotic strains to affect the re-epithelialization process in vitro, we investigated the involvement of NOS2 expression and activity in the mechanisms underlying the probiotic effects in the model of scratched keratinocyte monolayer
Keratinocyte proliferation and migration represent an essential step in the re-epithelialization process during wound healing [42]

Summary

Introduction

According to the Food and Agriculture Organisation of the United Nations (FAO) and the WorldHealth Organisation (WHO), probiotics are defined as live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host [1,2]. There is a growing body of research involving the use of a topical application of probiotics in dermatology with benefits in atopic dermatitis, acne, seborrheic dermatitis, and wound healing [4,7,8,9,10]. In this context, for some years, our group has been focusing the attention on studies aimed to investigate, in vitro and in vivo, the effects of selected probiotic strains on skin.

Methods

Results

Conclusion