Biological Activities of Essential Oils and Hydrolates from Different Parts of Croatian Sea Fennel (Crithmum maritimum L.)

The traditional nutritional use of sea fennel (<i>Crithmum maritimum</i> L.) has been rediscovered and reestablished, making this halophyte plant a prominent ingredient in coastal cuisine and a subject of interest in various scientific disciplines, including pharmacy and medicine. The first objective of this study was to identify the volatile profiles of essential oils (EOs) and hydrolates derived from the leaves, flowers, and fruits of sea fennel using gas chromatography-mass spectrometry. A total of 25 different volatiles were identified in the EOs and 63 were identified in the hydrolates. Limonene was the most abundant component in the EOs (74.85%, 74.30%, and 67.41%, respectively), while in the hydrolates, it was terpinen-4-ol in the leaves (27.8%) and the flowers (36.7%) and (<i>Z</i>)-carveol in the fruits (11.4%). The second objective was to investigate the biological activities of the samples. The antioxidant and choline inhibitory activities of hydrolates were generally low, with the flower hydrolate providing the inhibition of both enzymes and the leaf hydrolate with the highest antiradical activity. The cytotoxic activities of the EOs and hydrolates were also investigated. The human breast adenocarcinoma cell line MDA-MB-23 was the most sensitive against EOs from the flowers and fruits, reaching the IC₅₀ after 48 and 72 h, respectively. The leaf hydrolate exhibited cytotoxic activity after 72 h, while the flower hydrolate was effective after 48 h. The MCF-7 cell line was sensitive to the flower and fruit EOs, and the IC₅₀ was reached at all the tested periods. Overall, the results highlight sea fennel as a rich source of bioactive compounds that have significant potential for greater utilization in the nutraceutical and pharmaceutical industries.