Valuing the Endangered Species Antirrhinum lopesianum: Neuroprotective Activities and Strategies for in vitro Plant Propagation

Abstract

Plant phytochemicals are described as possessing considerable neuroprotective properties, due to radical scavenging capacity and acetylcholinesterase inhibitory activity, important bioactivities in neurodegeneration. Antirrhinum lopesianum is a rare endemism from the Iberian Peninsula, occurring at the northeastern border between Portugal and Spain. It is classified as Endangered, due to its highly fragmented geographical occupation, facing a high risk of extinction in the Portuguese territory, within 20 years. Here, we describe for the first time the chemical characterization of extracts of the species concerning total phenol content, flavonoid content and antioxidant properties. The profile of high performance liquid chromatography with diode array detector (HPLC-DAD) of the polyphenol-enriched fraction of plant extracts was also performed, showing the great potential of the species as a source of bioactive phytochemical compounds. A. lopesianum’s potential for neuroprotection was revealed by a significant acetylcholinesterase inhibitory activity and also by a neuroprotective effect on a human cell model of neurodegeneration. Moreover, this is the first report describing a successful procedure for the in vitro propagation of this endangered species. The comparison of phenolic content and the HPLC-DAD profile of wild and in vitro propagated plants revealed that in vitro plants maintain the ability to produce secondary metabolites, but the profiles are differentially affected by the growth regulators. The results presented here greatly contribute to the value for this species regarding its potential as a source of phytochemicals with prospective neuroprotective health benefits.

Polyphenols Beyond Barriers: A Glimpse into the Brain

“…Green tea and white tea digested metabolites were described to inhibit AChE [ 119 ]. Additionally, a variety of plants with diverse phytochemistry features have been reported to exhibit AChE inhibitory activity [ 120 ] and, in some of these studies, polyphenols were the compounds associated with the plant extract activity [ 118 , 121 - 126 ].…”

Chemical characterization and bioactivity of phytochemicals from Iberian endemic Santolina semidentata and strategies for ex situ propagation

“…To evaluate the neuroprotective effect of extracts, SK-N-MC neuroblastoma cells were incubated in the presence of H 2 O 2 (Gomes et al, 2013;Tavares et al, 2012a,b). Briefly, cells were seeded at 7.4 × 10 4 cells mL −1 and, 24 h after seeding, growth medium was removed and wells were washed with PBS.…”

“…PEF of S. semidentata was concentrated under vacuum and dissolved in cell medium for the cytotoxicity tests (Fortalezas et al, 2010;Gomes et al, 2013;Tavares et al, 2012a,b). The cell viability assay was performed in a 96 well plate cell with a neuroblastoma human cell line SK-N-MC.…”

“…Nontoxic ranges of the extract were defined using a neuroblastoma cell line for a range of 0-200 g GAE mL −1 for 24 h (Gomes et al, 2013;Tavares et al, 2012a,b). To cause a complete cell death, a concentration of 100 g GAE mL −1 S. semidentata PEF is required ( Fig.…”

“…HPLC analysis of S. semidentata PEF was performed as described earlier (Hitachi HPLC instrument (VWR) equipped with EZChrom Elite software (Agilent), Inertsil ODS-3 V column) (Gomes et al, 2013).…”