Phytochemical Profile and Antioxidant, Enzyme-Inhibitory, and Cytotoxic Potential of Endemic <i>Cynoglottis chetikiana</i> subsp. <i>chetikiana</i>

Background Cynoglottis chetikiana subsp. chetikiana, an endemic Boraginaceae plant growing in Turkey, has not been previously studied in terms of pharmacognosy. However, related species, such as Anchusa, Symphytum, and Rindera, have been known for their pharmacological effects attributed to compounds such as flavonoids, terpenoids, and other phenol derivatives. Objectives This study aimed to reveal the phytochemical composition and potential biological activity of C. chetikiana. Materials and Methods Phytochemical profiling analysis was performed by using the liquid chromatography–high-resolution mass spectrometry (LC–HRMS) system. The cytotoxic effects of the extracts were evaluated on the MCF-7 mammalian breast cancer cell line by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The in vitro α-glucosidase and tyrosinase enzyme inhibitory activities were assessed using literature methods. Additionally, antioxidant properties were investigated, leading to the bioactivity-guided isolation of the most active substance. Results LC–HRMS analysis revealed 26 major phenolic compounds and 1 pyrrolizidine alkaloid in C. chetikiana. Bioactivity-guided studies led to the isolation of a flavonoid, rutin. The n-butanol extract of the plant exhibited high antioxidant capacity and was rich in phenolic compounds. The methanol extract of C. chetikiana demonstrated low-moderate α-glucosidase inhibitory activity (IC50 = 608.62 ± 7.01 µg/mL). Moreover, the methanol extract showed significant anti-tyrosinase enzyme activity (195.84 ± 5.81 mg Kojic acid equivalent/g extract), and the petroleum ether extract displayed the highest cytotoxicity on MCF-7 cells (IC50 = 76.91 ± 3.12 µg/mL). Conclusion This is the first phytomedicinal study report for C. chetikiana, which gives promising insight for further pharmaceutical research.