Biological properties and phytochemical analysis of the halophyte Armeria maritima Willd. (Plumbaginaceae)

Halophytes, such as Armeria maritima are salt-tolerant plants [1]. Their ability to grow in saline stressful environment is due to special physiology and morphology. Due to these metabolic features, they are a potential source of active ingredients for cosmetics [2].

An hydro-alcoholic extract prepared from the dried aerial parts of A. maritima was partitioned successively with water and cyclohexane, dichloromethane, ethyl acetate and then n-butanol. The crude extract and these fractions were submitted to different biological tests. At first, phototoxicity on human fibroblasts was evaluated. Only the two apolar fractions showed phototoxicity after UVA irradiation (- 97% of cellular viability at 25 µg/mL). Then in tubo evaluations on elastase and collagenase activities were performed. The crude extract shown a slight anti-elastase effect (21% of inhibition at 100 µg/mL) but a marked anti-collagenase activity at 100 µg/mL (100% of inhibition) with a dose-effect correlation to 10 µg/mL. The two polar fractions (EtOAc, BuOH) also displayed good activity against collagenase (26% and 52% of inhibition at 100 µg/ml, respectively). Finally, antioxidant activity, assessed using the ORAC method, revealed a high antioxidant capacity for these two last fractions (12.6 and 8.2 mmol TE/g, respectively). In order to identify the constituents responsible to those activities, phytochemical investigation was lead and focused firstly on polar fractions. Our fractionation strategy (liquid/liquid partition, preparative chromatographic techniques) and combination of LC-HRMS and NMR experiments, led us to the isolation and identification of several compounds such as phenolic acids and flavonoids. Myricetin α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside, myricetin α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside and myricetin-3-O-α-L-rhamnoside were the major compounds, described for the first time in Armeria spp. Further studies on biological properties of previously described compounds will be undertaken.

Keywords: Armeria, phototoxicity, collagenase, antioxidant, polyphenols.

References:

[1] Flowers TJ, Colmer TD. Salinity tolerance in halophytes. New Phytol 2008; 179: 945 – 963

[2] Buhmann A, Papenbrock J. An economic point of view of secondary compounds in halophytes. Funct Plant Biol 2013; 40: 952 – 967