This work explored the medicinal halophyte Frankenia laevis L. (sea heath) as a potential source of bioactive natural products. In this sense, methanol and dichloromethane extracts were prepared from aerial organs containing flowers, leaves and stems, and were profiled for their chemical composition using high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS). The extracts were evaluated for their in vitro antioxidant capacity using five complementary methods: enzyme inhibitory effects on enzymes related with neurodegeneration (acetyl (AChE) and butyrylcholinesterase (BuChE)), Type 2 diabetes (α-glucosidase and α-amylase), hyperpigmentation/food oxidation (tyrosinase), and cytotoxicity towards human hepatocarcinoma (HepG2) cells. Fifty-one molecules were identified in the extracts, including several derivatives of phenolic acids, lignans and flavonoids, monoterpenes, and hydroxylated derivatives of linoleic acid. The methanol extract was effective in DPPH and ABTS radical scavenging (EC50 = 0.25 and 0.65 mg/mL, respectively), copper chelation (EC50 = 0.78 mg/mL), and iron reduction (EC50 = 0.51 mg/mL) activities, whereas the dichloromethane extract had high iron chelating ability (EC50 = 0.76 mg/mL). Both extracts showed the capacity to inhibit α-glucosidase, especially the dichloromethane (EC50 = 0.52 mg/mL). This extract also exerted a significant selective cytotoxicity towards HepG2 cells (EC50 = 52.1 μg/mL, SI > 1.9). In conclusion, extracts from the aerial parts of sea heath were shown to be a promising source of natural products for pharmaceutical and/or food additive applications due to their high antioxidant, anti-diabetic, and cytotoxic properties.
Keywords: Frankenia laevis; anti-tumor; monoterpenes; phenolics; salt-tolerant plants; type 2 diabetes.