Photoprotective Effect and Potential Mechanisms of Gardeniae Fructus Extract in UVB-Irradiated HaCaT Cells

Gardeniae Fructus (GF), the desiccative mature fruitage of Gardenia jasminoides J. Ellis (G. jasminoides), is a traditional herbal medicine in China with potential value against skin photodamage. However, the phytochemical basis and mechanisms underlying GF’s anti-photodamage effects remain unclear. In this study, the chemical components in GF extract (GFE) were analyzed using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS), and iridoids were identified as the main components. The antioxidant, anti-inflammatory, and barrier-repair effects of GFE in UVB-induced photodamage were assessed through in vitro experiments. Additionally, the potential mechanisms of GFE against skin photodamage were predicted using proteomics and network pharmacology. The results showed that GFE significantly increased the levels of total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) induced by UVB, while decreasing reactive oxygen species (ROS) and malondialdehyde (MDA) contents. GFE also inhibited the secretion of interleukin-6 (IL-6) and interleukin-1β (IL-1β). Additionally, GFE upregulated the expression of filaggrin (FLG), loricrin (LOR), and involucrin (IVL) in 3D epidermal skin models. Proteomic analysis and network pharmacology indicated that the iridoid components identified in GFE ameliorated UVB-induced damage probably by regulating cell cycle-related proteins and signaling pathways, though this requires further experimental confirmation. Overall, the results provide essential evidence to support the development of GFE as a skincare active ingredient.