Radical scavenging activity of phenolic constituents from Limonium latifolium
Limonium latifolium Kuntze (syn. L. gerberi Soldano) or sea lavender is a member of the highly stress-tolerant family Plumbaginaceae found in Brittany (France) littoral. Salt-tolerance capacity of this halophyte may include mechanisms like compartmentation of toxic ions, osmolites accumulation and redox control making this synthetic pathway an interesting target for radical scavenging activities (RSA) [1, 2]. In this study, we investigate the bioactive constituents of L. latifolium with RSA using in vitro superoxide anion (O2 –) and hydroxyl radical (.OH) inhibition assays. Preliminary anti-oxidant screening has shown the scavenging capacity of a crude hydro-alcoholic extract of the two free radicals? OH and O2 – (62.0% and 68.8% of inhibition at 2 and 25µg.mL–1, respectively). Bioguided fractionation permit us to isolate 6 major constituents with potent RSA against OH and O2 .–. Their identification by HPLC-DAD, NMR and MS data shown that they consist of gallic acid, ethyl gallate, myricitrin, epicatechin gallate, kaempferol 3-O-glucoside and myricetin 3-O-galactoside, all of them identified for the first time in this species. Thus, the strong anti-oxidative potential of these polyphenols could explain the adaptability of sea lavender to hostile biotopes and may contribute to a potent pharmacological effect.
References: 1. Plant Sci. 160 (2001) 415–423
2. Plant Cell Physiol. 44 (2003) 388–394.