Antioxidant capacity of Macaronesian traditional medicinal plants.
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 microg 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.
Tavares
Lucélia
L
Disease & Stress Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal. ltavares@itqb.unl.pt
Carrilho
Dina
D
Tyagi
Meenu
M
Barata
David
D
Serra
Ana Teresa
AT
Duarte
Catarina Maria Martins
CM
Duarte
Rui Oliveira
RO
Feliciano
Rodrigo Pedro
RP
Bronze
Maria Rosário
MR
Chicau
Paula
P
Espírito-Santo
Maria Dalila
MD
Ferreira
Ricardo Boavida
RB
dos Santos
Cláudia Nunes
CN
D000596:Amino Acids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D019684:Magnoliopsida / Q000737:chemistry*; D027444:Ocotea / Q000737:chemistry; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D010943:Plantago / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011174:Portugal; D027861:Prunus / Q000737:chemistry; D031804:Rumex / Q000737:chemistry; D012645:Selenomethionine / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D014131:Trace Elements / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
D000596:Amino Acids; D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D014131:Trace Elements; D012645:Selenomethionine