Evaluation of Daphne pontica L. with its cytotoxic and antidiabetic effects

Daphne L. genus belongs to the Thymelaeaceae family and is distributed in Anatolia with 7 species. The genus Daphne is found mainly in the North and North East Anatolian Region in Türkiye. There are limited studies on D. pontica, a Daphne species from Turkish flora. For this reason, research on the stems, leaves, and fruit parts of D. pontica, constitute the subject of this master course thesis. The purpose of this study is to determine the antioxidant, antidiabetic, and cytotoxic activities and clarify the phytochemical content of D. pontica. The total phenolic and flavonoit contents of the plant's stems, leaves, and fruits were also determined, and TLC analyses were carried out. Its phytochemical structure was examined using UHPLC-Q-Exactive-Orbitrap HRESIMS. In this study, Daphne pontica has been found to be rich in terpenic compounds, especially daphnan type diterpenes. In D. pontica stems, kirkinin D, excoecaria factor O1, vikstroelite M, yuanhuadin, pimelotite A, exocariatoxin, simplexin, acetoxyhuratoxin, huratoxin; in leaves, kirkinin D, excoecaria factor O1, vikstroelite M, yuanhuadin, pimelotite A, simplex, acetoxyhuratoxin, huratoxin. The presence of simplex and huratoxin was determined in the fruits. The antidiabetic activity of the plant was also evaluated, and it was determined that the α-glucosidase inhibitory effect was higher than the α-amylase inhibitory effect and this activity was due to phenolic compounds. In addition, according to our MTT test results, it was observed that Daphne pontica extracts have selective cytotoxic effects. Also, according to MTT assays, fruit extract (IC50: 0.467 mg/mL) had the most increased cytotoxic activity in the A-549 cell line; It was determined that fruit (IC50: 0.937 mg/mL) extract in the HeLa cell line and stems extract (IC50: 0.896 mg/mL) in MCF-7 cell line. As a result, the ethereal extracts of Daphne pontica are rich in daphnane-type diterpenoids, and the fruits contain more coumarin than the branches and leaves. In terms of anticancer activity, a promising anticancer activity was demonstrated, depending on the concentration and the extract. Promising results were also obtained in enzyme inhibition tests indicating antidiabetic activity. According to our results, D. pontica can be expressed as a valuable source of natural agents to fight cancer, infectious diseases and metabolic diseases.