The cell membranes undergo biochemical and biophysical changes in response to hydroxycinnamic acid derivatives: ferulic acid and caffeic acid.

Ferulic acid (FA) and caffeic acid (CA), due to their strong antioxidant properties, are widely used both in dietary supplements and as ingredients in cosmetics. However, despite the undoubtedly beneficial properties of these molecules, they can also exhibit toxic effects. This study aimed to investigate which concentrations of the compounds are toxic for different types of cells and which are beneficial. Detailed analyses were performed on human cells (U937, HL-60, SK-N-SH) and mouse cells (B16-F0), as well as on cell membrane models created using the Langmuir technique. Based on biochemical studies, it was shown that both compounds can act cytotoxically, although FA is significantly more cytotoxic than CA. This difference in toxicity levels is attributed to the presence of different substituents, which affect the molecules' hydrophobicity and, consequently, their localization in membranes. Based on model membranes, it was demonstrated that the polar parts of membranes are decisive in determining the degree of this interaction. While cinnamic acid derivatives offer localized health benefits, they can also have toxic effects on different types of cells.