| dc.description.abstract | Neurodegenerative diseases (NDDs) are a consequence of progressive neuronal cell death that is
generally associated with the accumulation of protein aggregates in the central nervous system and
leads to loss of cognitive or motor function. There is increasing evidence that the homeostasis of
transition metals, such as Cu, Zn and Fe, are deregulated in NDDs. Transition metal ions are able of
establishing more than a single cation with different charges therefore they are highly toxic and usually
tightly bound to proteins. Metal chelation therapy is used for diseases caused by an excess of these
metal ions. Polyphenols are considered candidate chelation therapeutics. Cistus albidus is a
Mediterranean medicinal plant which was traditionally used as a remedy for symptoms consistent
with Parkinson's Disease (PD) and other neurophysiological disorders. Its pharmaceutical properties
are due to its polyphenolic composition, but the scientific evidence on this issue is still scarce.
The aim of the present work is the comparison of different phenolic profiles of C. albidus extracts to
draw conclusions about the influence of the culture conditions on the polyphenolic composition and
thus on the antioxidant capacity. Therefore, hexane and aqueous extracts were compared with a
benchmark extract used in traditional treatment of symptoms consistent with PD. For this purpose,
a suitable UHPLC-QqQ-ESI-MS/MS method was developed, to identify the polyphenolic
compounds after extraction and different antioxidant capacity tests were assayed..
Cultivation parameters have shown a significant impact on the total phenol content, antioxidant
capacity and the profile of polyphenols. Especially stress induction with simultaneous soil
amendment had a positive influence. Results suggest that C. albidus’ antioxidant activity is primarily
dependent on its flavonol composition. Phenolic acids were the second major group and should also
play an important role on this activity. On the other hand, the proportion of ellagitannins is
significantly lower, which could mean that these hydrolysable tannins play a smaller role in the
supposed neurophysiological activity of C. albidus.
Besides, a new polyphenol with antineoplastic properties was detected: To our knowledge, this is the
first time that a ligstroside derivative was identified in C. albidus. Furthermore (epi)gallocatechin-
(epi)gallocatechin is proposed to be a botanical biomarker to indicate biotic stress to which the plant
material was subjected.
And finally, prodelphinidin B2-3´-O-gallate as the most common single substance, present in all
extracts, with extraordinary chelating properties and antioxidant capacity could be a key factor for
the neurophysiological properties of C. albidus. For this reason, this compound is proposed to be
used as a quality biomarker for the pharmacological activity of C. albidus. | es_ES |
