Purpose: To investigate the phenolic profile and biological activities of Argania spinosa L. leaves.
Methods: The crude methanol extract of leaves of A. spinosa L. Skeels was obtained by ultrasonic
extraction, and the total polyphenolic and flavonoid contents were determined by ultra-high performance
liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (UPLC-ESIQTOF-MS). In vitro antioxidant activity was determined by 2,2-di-phenyl-1-picryl-hydrazil (DPPH) radical
assay and antimicrobial activity evaluated using agar disk diffusion method against reference
pathogenic strains (
Bacillus subtilis
ATCC 6633,
Bacillus cereus
ATCC 14579,
Yersinia enterocolitica
ATCC 23715,
Staphylococcus aureus
ATCC 25923,
Pseudomonas aeruginosa
ATCC 27853,
Escherichia coli
ATCC 25922). Cytotoxic activity was evaluated by methyl-thiazolyldiphenyl-tetrazolium
bromide (MTT) assay.
Results: The results revealed abundant polyphenols and flavonoids (221.39 ± 5.70 μg GAEq/1 g and
66.86 ± 3.36 μg CAEq/1 g, respectively) in the leaf extract. UPLC-DAD-ESI-QTOF-MS profiling showed
the presence of myrecitin-3-galactoside, myrecitin-3-gluctoside, myrecitin-3-xyloside, quercetin-3-galactoside, quercetin-3-glucoside, quercetin-3-arabinofuranoside, and quercetin-3-rhamnoside. DPPH
assay of the leaf extract yielded a half-maximal effective concentration (EC
50) value of 125.60 ± 1.87 μg.
A. spinosa L. leaves exhibited antibacterial activity against Gram (+) and Gram (-) bacteria, with
particularly marked activity against
B. subtilis (inhibition zone, 16 mm). Cytotoxicity data showed that the
extract inhibited the proliferation of PC3 cells (IC
50 ~ 600 μg).
Conclusion: A. spinosa L. leaf extract is rich in valuable biologically active compounds and could
represent a new resource for natural and preventive therapies.
