Phytochemical Profiling and Biological Evaluation of Dianthus sylvestris subsp. aristidis: A Chromatographic and Mass Spectrometry Approach to Uncovering Bioactive Metabolites for Dermatological and Metabolic Disorder Management

<b>Background/Objectives</b>: This study provides the first comprehensive phytochemical composition and biological evaluation of <i>Dianthus sylvestris</i> subsp. <i>aristidis</i> (Batt.) Greuter & Burdet, a plant endemic to Algeria with unexplored pharmacological potential. The objective is to identify novel bioactive metabolites in the plant's extracts and assess their potential applications for skincare and metabolic disorder management, addressing gaps in the current understanding of its medicinal value. <b>Methods</b>: Liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) profiling was used to analyze the hydromethanolic (HMeOH) leaf extract and identify bioactive compounds. The biological activities of HMeOH, ethyl acetate (EtOAc), and butanolic (n-BuOH) extracts were tested for cytotoxicity using the brine shrimp lethality test, photoprotective potential by calculating the sun protection factor (SPF), and enzymatic inhibitory activities against alpha-amylase, urease, and tyrosinase. <b>Results</b>: The LC-ESI-MS/MS profiling of the MeOH extract identified 22 bioactive compounds, including phenolic acids and flavonoids, some of which have not been previously reported in this species. Cytotoxicity tests showed that all extracts were non-toxic (half-lethal concentration (LC₅₀) > 100 micrograms per milliliter). The SPF values indicated significant photoprotective potential, with EtOAc (SPF = 45.19 ± 0.73) and n-BuOH (SPF = 43.81 ± 0.59) extracts showing high sun protection activity. The n-BuOH extract exhibited strong alpha-amylase inhibitory activity (half-maximal inhibitory concentration (IC₅₀) = 307.08 micrograms per milliliter), surpassing the standard acarbose (IC₅₀ = 3650.93 micrograms per milliliter), suggesting potential applications in diabetes management. <b>Conclusions</b>: <i>Dianthus sylvestris</i> subsp. <i>aristidis</i> demonstrates significant pharmacological potential as a source of bioactive secondary metabolites for skincare and metabolic disorder management. These findings provide new insights into the plant's therapeutic potential and set a foundation for future pharmacological and clinical investigations.