This research was funded by the Foundation for Science and Technology (FCT, Portugal) for
financial support through national funds FCT/MCTES, CEEC-IND/00425/2017, UIDB/00690/2020,
CEECIND/01011/2018, UIDB/04326/2020, UIDP/04326/2020 and PTDC/BAA-AGR/1391/2020
projects. This study was also made under the frame of the project HaloFarMs, which is part of the
Partnership on Research and Innovation in the Mediterranean Area (PRIMA), funded by FCT in
Portugal and the Ministry of High Education and Scientific Research in Tunisia. M.J.R. was supported by the FCT program contract (UIDP/04326/2020) and L.C. by the FCT Scientific Employment
Stimulus (CEECIND/00425/2017).
This study assessed the halophyte species Limonium spathulatum (Desf.) as a possible source
of natural ingredients with the capacity to inhibit enzymes related to relevant human health disorders
and food browning. Extracts using food-grade solvents such as water and ethanol were prepared by
maceration from dried L. spathulatum leaves. They were evaluated for in vitro inhibition activity of
enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), -glucosidase, tyrosinase
and lipase, related to Alzheimer’s disease, type-2-diabetes mellitus, skin hyperpigmentation,
and obesity, respectively. These extracts were also appraised for in vitro acute toxicity on tumoral and
non-tumoral cell lines and their chemical composition by high-performance liquid chromatography
coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS). The extracts were
more effective towards BChE than AChE. The best results were obtained with the hydroethanolic and
water extracts, with IC50 values of 0.03 mg/mL and 0.06 mg/mL, respectively. The hydroethanolic
extract had the highest capacity to inhibit -glucosidase (IC50: 0.04 mg/mL), higher than the positive
control used (acarbose, IC50 = 3.14 mg/mL). The ethanol extract displayed the best inhibitory activity
against tyrosinase (IC50 = 0.34 mg/mL). The tested samples did not inhibit lipase and exhibited
low to moderate cytotoxic activity against the tested cell lines. The hydroethanolic extract had a
higher diversity of compounds, followed by the ethanol and water samples. Similar molecules were
identified in all the extracts and were mainly hydroxybenzoic acids, hydroxycinnamic acids, and
flavonoids. Taken together, these results suggest that L. spathulatum should be further explored as a
source of bioactive ingredients for the food, cosmetic, and pharmaceutical industries.
