Protective effect of protocatechuic acid against inflammatory stress induced in human dermal fibroblasts

Background: Protocatechuic acid (PCA) is an anthocyanin metabolite with a high antioxidant property. It is also known for having anticancer and anti-inflammatory capacities with diverse medicinal activities. As one of the active ingredients in plant sources, PCA has been studied and has revealed various mechanisms, but effects on cosmetology are not sufficient. This paper suggests the effects of PCA on cosmeceutical via antioxidant and senescence-inhibiting activities. Methods: Prior to demonstrating PCA efficacy, we performed cell viability of PCA of 0–100 μM with or without lipopolysaccharide (LPS) using water-soluble tetrazolium salt (WST-1). Then, to evaluate the antioxidant capacity, especially excessive generated reactive oxygen species (ROS), researchers carried out ROS scavenging activity of PCA through 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence intensity. Cellular senescence was assessed by senescence-associated β-galactosidase (SA-β-gal)-positive value, and extracellular matrix (ECM)-associated gene expression, collagen type I, alpha 1 chain (COL1A1), and matrix metalloproteinase-1 (MMP1) were estimated through quantitative real-time polymerase chain reaction (qRT-PCR). Results: PCA has not shown cellular toxicity under 100 μM, with or without LPS. The results demonstrated that PCA exerted an antioxidant effect on LPS-treated human dermal fibroblasts (HDFs), via ROS scavenging activity. Furthermore, PCA has shown the senescence attenuating efficacy in HDFs through reducing senescent cells and regulating COL1A1 and MMP1 gene expression. Conclusion: This work suggests the potential benefits of PCA against LPS-induced excessive ROS generation and cellular senescence, for the first time.