The influence of blackcurrant extract–based cosmetic antimicrobial agent on skin cells and skin model membranes

The components of blackcurrant extract are known for their antimicrobial properties and the lipid membrane is the important target in terms of the activity of these compounds. In this work, a commercially available product that is PhytoCide Black Currant Powder (BCE), which can be used as a soothing, conditioning and antimicrobial agent in cosmetics, was investigated. The aim of this study was to explore its effect on skin cells and gain insight into the mechanism of its selectivity. The influence of this formulation on keratinocyte and fibroblast cells in in vitro tests was studied and the effect of BCE on model keratinocyte and fibroblast membranes was investigated. As model systems, the lipid monolayers of different compositions were used. The experiments involved the surface pressure/area measurement, penetration studies and Brewster angle microscopy experiments. The BCE formulation was shown to be non-toxic to the skin cells at the concentrations applied. Model membrane experiments confirmed that BCE components do not incorporate into keratinocyte and fibroblast membranes at membrane-related conditions. However, they alter morphology of the studied systems by acting in the region of polar head. Significant differences were found in the affinity of the BCE formulation for bacteria compared to skin lipids, consistent with the proven antibacterial effect of the preservative while lacking toxicity to skin cells. Thus, the membrane of the cell may be critical to the selectivity of the chemicals being tested. • Black Currant Fruit Extract (BCE) can be used as a cosmetic preservative. • BCE formulation is non-toxic to the skin cells at the concentrations applied. • The components of BCE do not incorporate into the skin cells model membranes. • BCE formulation has significantly different affinity for bacteria vs skin lipids. • Membrane lipids may be critical to the selectivity of BCE preservative.