AUTHOR=Türkan Ali , Türkoğlu Murat , Öncü Gülistan , Sevinç Hakan TITLE=3-O-ethyl-L-ascorbic acid modulates pro-inflammatory cytokine and extracellular matrix-related biomarker levels in human lung fibroblasts: an in vitro study JOURNAL=Acta Biochimica Polonica VOLUME=Volume 73 - 2026 YEAR=2026 URL=https://www.frontierspartnerships.org/journals/acta-biochimica-polonica/articles/10.3389/abp.2026.16774 DOI=10.3389/abp.2026.16774 ISSN=1734-154X ABSTRACT=L-Ascorbic acid (also known as vitamin C) is widely used in dietary supplements and cosmetic formulations because of its antioxidant properties and critical role in numerous physiological processes. In this study, we investigated the effects of 3-O-ethyl-L-ascorbic acid (EAA), a stable vitamin C derivative, on inflammatory and extracellular matrix (ECM)-related biomarkers in MRC-5 human lung fibroblasts. We quantified protein levels of pro-inflammatory cytokines, ECM-associated proteins, and matrix-degrading enzymes using enzyme-linked immunosorbent assay (ELISA)-based assays. EAA treatment significantly reduced the basal levels of interleukin-1 Beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), indicating modulation of inflammatory signaling under unstimulated conditions. EAA also increased the levels of collagen type I (COL-I), collagen type III (COL-III), and hyaluronan synthase 2 (HAS2), suggesting enhanced production of ECM-associated components. In addition, EAA altered the levels of matrix-degrading enzymes in a time-dependent manner. Matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-9 (MMP-9) exhibited a biphasic response characterized by higher levels at 24 h and lower levels at 48 h, whereas elastase levels were consistently reduced. Taken together, these findings suggest that EAA modulates inflammatory, ECM-associated, and ECM-degrading biomarker levels in MRC-5 fibroblasts under the tested in vitro conditions. Further studies are needed to determine whether these changes have functional implications for ECM homeostasis.