Antioxidant and neuroprotective potential of two halophytes from the Algarve coast

The in vitro neuroprotective properties of methanol and dichloromethane extracts of roots and aerial parts of the halophytes Limonium algarvense and Polygonum maritimum was evaluated by determining their in vitro inhibitory activity against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase (TYRO). Moreover, the copper and iron chelating activity and the iron reducing potential of the extracts were also determined. The methanol extract of P. maritimum aerial part had the highest iron reducing capacity (IC₅₀= 0.05 mg/mL), coupled with a high copper chelating potential (IC₅₀= 0.29 mg/mL). The methanol extracts of the roots and of the aerial parts of P. maritimum demonstrated notable inhibitory capacity of AChE (IC₅₀= 0.17 mg/mL and 0.27 mg/mL, respectively). In the BChE inhibitory assay, the roots of L. algarvense exhibited the lowest IC₅₀ (IC₅₀= 0.43 mg/mL). The methanolic extracts of P. maritimum roots and aerial part revealed good TYRO inhibitory activity (IC₅₀= 0.59 mg/mL and 0.60 mg/mL, respectively). Our results suggests that P. maritimum and L. algarvense could be a valuable source of molecules useful for alleviating symptoms associated with Alzheimer's disease and other neurodegenerative disorders.

Acknowledgements: This work was supported by XtremeBio (PTDC/MAR-EST/4346/2012) project funded by the Foundation for Science and Technology (FCT) and the Portuguese National budget.

Keywords: Limonium algarvense, Polygonum maritimum, chelating activity, acetylcholinesterase, butyrylcholinesterase, tyrosinase