Abstract
The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, essential to identify the bioactive compounds present. The leaves from five species endemic to the Macaronesian islands with recognized ethnobotanical applications were analysed: Apollonias barbujana (Cav.) Bornm., Ocotea foetens (Ainton) Baill, Prunus azorica (Mouill.) Rivas-Mart., Lousã, Fern. Prieto, E. Días, J.C. Costa & C. Aguiar, Rumex maderensis Lowe and Plantago arborescens Poir. subsp. maderensis (Dcne.) A. Hans. et Kunk.. Since oxidative stress is a common feature of most diseases traditionally treated by these plants, it is important to assess their antioxidant capacity and determine the molecules responsible for this capacity. In this study, the antioxidant capacity of these plants against two of the most important reactive species in human body (hydroxyl and peroxyl radicals) was determined. To trace the antioxidant origin total phenol and flavonoid contents as well as the polyphenolic profile and the amount of trace elements were determined. There was a wide variation among the species analysed in what concerns their total leaf phenol and flavonoid contents. From the High Performance Liquid Chromatography (HPLC) electrochemically detected peaks it was possible to attribute to flavonoids the antioxidant capacity detected in A. barbujana, O. foetens, R. maderensis and P. azorica extracts. These potential reactive flavonoids were identified for A. barbujana, R. maderensis and P. azorica. For R. maderensis a high content (7 mg g-1 dry weight) of L-ascorbic acid, an already described antioxidant phytomolecule, was found. A high content in selenomethionine (414.35 μg g-1 dry weight) was obtained for P. arborescens subsp. maderensis extract. This selenocompound is already described as a hydroxyl radical scavenger is reported in this work as also possessing peroxyl radical scavenging capacity. This work is a good illustration of different phytomolecules (flavonoids, organic acids and selenocompounds), presents in leaves of the five traditional medicinal plants endemic to Macaronesia, all exhibiting antioxidant properties.
Highlights
Oxidative stress represents a disturbance in the equilibrium status of prooxidant/antioxidant reactions in living organisms
High Performance Liquid Chromatography (HPLC) analysis revealed that the water-ethanol extract possessed all peaks detected in the three types of extractions but in higher quantities
A. barbujana presented the highest content in total phenolics in the water-ethanol extract (35.8 mg GAE g-1 dw, Table 2); all other species had values lower than
Summary
Oxidative stress represents a disturbance in the equilibrium status of prooxidant/antioxidant reactions in living organisms. The balance between antioxidants and damaging effects of free radicals is a very important aspect and is achieved by mechanisms collectively termed “redox regulation”, that protect living organisms from oxidative stresses [1]. The study of ROS and antioxidants in biology triggered a medical revolution that underlies a new age of health and disease management [3]. The continuous upsurge of new challenges ranges from prevention of oxidative reactions in foods to novel pharmaceuticals for treatment/attenuation of chronic degenerative diseases, such as cancer, autoimmune, inflammatory, cardiovascular and neurodegenerative (e.g., Alzheimer's disease, Parkinson's disease, multiple sclerosis, Down’s syndrome) diseases, as well as ageing and cosmetics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
