Metabolomic profiling and biological properties of six Limonium species: novel perspectives for nutraceutical purposes†
The genus Limonium includes important halophyte plants containing a variety of bioactive compounds of therapeutic interest. In the present work, the untargeted phytochemical profiles of both aerial part and root extracts from six Limonium species namely, L. bellidifolium, L. globuliferum, L. gmelinii, L. lilacinum, L. sinuatum and L. iconicum from Turkey were determined. Furthermore, several biological activities (in vitro antioxidant and enzyme inhibitory effects) were investigated. Overall, significant amounts of total phenolics (43.64–238.18 mg g−1) and flavonoids (1.61–129.69 mg g−1) were recorded. Particularly, the root extracts of L. gmelinii, L. iconicum and L. globuliferum showed the highest total phenolic content (204.13–238.18 mg g−1), whilst the highest total flavonoid content was recorded in the root extracts of L. gmelinii (129.69 mg g−1). Overall, the tested extracts demonstrated potent radical scavenging activities in both DPPH (2,2- diphenyl-1-picrylhydrazyl) and ABTS (3-ethylbenzothiazoline-6-sulphonic acid) (90.10–507.94 mg g−1 and 163.39–1175.34 mg g−1, respectively). However, the highest scavenging potential (p < 0.05) was displayed by the root extracts of L. iconicum. Conversely, the metal chelating ability assay revealed that L. lilacinum root extract showed the highest activity (21.03 mg g−1). Interestingly, all the extracts were found to be active inhibitors of cholinesterases (AChE (acetylcholinesterase): 4.20–5.11 mg GALAE (galantamine equivalent) per g; BChE (butyrylcholinesterase): 3.89–10.75 mg GALAE per g), amylase (0.52–1.09 mmol ACAE (acarbose equivalent) per g) and tyrosinase (119.41–155.67 mg KAE (kojic acid equivalent) per g), unlike for glucosidase (2.31–2.41 mmol ACAE per g). Taken together, these findings demonstrated a diverse chemical profiles and biological of the extracts, to be potentially considered as phytotherapeutic or functional ingredients due to their antioxidant properties and inhibition of key enzymes involved in several diseases.