Antioxidant Profile of Origanum dictamnus L. Exhibits Antiaging Properties against UVA Irradiation

Abstract

Skin aging mainly occurs due to intrinsic and extrinsic factors. Extrinsic aging is a consequence of exposure to ultraviolet radiation. Meanwhile, natural products exhibit protective properties against skin aging as well as photoaging. In this context, the research on natural anti-aging agents is greatly advanced, and in recent years, numerous plant-based products have been investigated. The aim of this study was to assess the antioxidant profile of Origanum dictamnus L. extract as well as its antiaging effects on 2D cultures of fibroblasts and keratinocytes under UVA irradiation to unravel the potential role of Origanum dictamnus L. in cosmetology. In an attempt to explore the antioxidant profile of the extract, we employed well-established enzymatic assays (DPPH, FRAP, ABTS, and TPC) and a phytochemical screening by LC/MS. According to our findings, the Origanum dictamnus L. extract possesses high scavenging activity (DPPH, ABTS), high phenolic content (TPC), and high Fe(III)-reduction activity (FRAP). Moreover, the LC/MS analysis revealed that the extract was rich in flavonoids, holding a high content of curcumin, kampferol, silymarin, cyanidin-3-glucoside, deosmin, rutin, and quercetin. To gain insight into the bioactivity of Origanum dictamnus L. extract in cell aging, the expression of various genes that are implicated in the skin aging process in keratinocytes and fibroblasts was studied. The gene expression analysis revealed that the extract increases cell proliferation in the cells exposed to UVA irradiation and concomitantly modulates the expression of genes related to the aging process in keratinocytes (KLK7, OCLN, GBA1) and fibroblasts (SIRT2, FOXO3, COL3A1) under the same conditions.