Sea fennel (Crithmum maritimum L.) leaves and flowers: Bioactive compounds, antioxidant activity and hypoglycaemic potential

Sea fennel (Crithmum maritimum L.) leaves and flowers from Italian wild and cultivated populations were herein investigated for their content of carotenoids and tocopherols using ultra-high-performance liquid chromatography coupled with the photodiode array and fluorimeter detectors to assess their functional value. Moreover, aqueous extracts were prepared to explore in vitro bioactivities never tested in this halophyte herb. Thus, chlorogenic acid-enriched sea fennel extracts were evaluated for their major bioactive compounds, antioxidant potential, pancreatic lipase, and carbohydrate hydrolase inhibitors. Neoxanthin, violaxanthin, lutein, zeaxanthin, β-carotene, and α- and γ-tocopherols were identified. C. maritimum can be considered a high source of lutein, vitamin A, and vitamin E up to 19.1, 1.85 and 52.81 mg/100 g of dried leaves, respectively. Despite a low TPC content, a promising ABTS+. radical scavenging activity (CON-L-WT, IC50 value of 3.83 μg/mL) and the highest FRAP value were observed in the wild leaves extract of Conero Park of Marche Region. The water extract from the wild Sicilian leaves was the most active against pancreatic lipase. The evidence herein suggests that sea fennel extract might be potentially used in the formulation of nutraceuticals for the prevention of diseases associated with oxidative stress and hyperglycemic conditions.