Proanthocyanidin Characterization and Bioactivity of Extracts from Different Parts of Uncaria tomentosa L. (Cat’s Claw)
Mirtha Navarro-Hoyos,
Rosa Lebrón-Aguilar,
Jesús E. Quintanilla-López,
Carolina Cueva,
David Hevia,
Silvia Quesada,
Gabriela Azofeifa,
M. Victoria Moreno-Arribas,
María Monagas,
Begoña Bartolomé
Affiliations
Mirtha Navarro-Hoyos
Department of Chemistry, University of Costa Rica (UCR), Sede Rodrigo Facio, San Pedro de Montes de Oca, San José 2060, Costa Rica
Rosa Lebrón-Aguilar
Institute of Physical Chemistry “Rocasolano”, CSIC,C/ Serrano 119, Madrid 28006, Spain
Jesús E. Quintanilla-López
Institute of Physical Chemistry “Rocasolano”, CSIC,C/ Serrano 119, Madrid 28006, Spain
Carolina Cueva
Institute of Food Science Research (CIAL), CSIC-UAM, C/ Nicolás Cabrera 9, Madrid 28049, Spain
David Hevia
IUOPA-Redox Biology Group, Department of Cellular Morphology and Biology, Faculty of Medicine, University of Oviedo, C/ Julian Claveria 6, Oviedo 33006, Spain
Silvia Quesada
Department of Biochemistry, School of Medicine, University of Costa Rica (UCR), Sede Rodrigo Facio, San Pedro de Montes de Oca, San José 2060, Costa Rica
Gabriela Azofeifa
Department of Biochemistry, School of Medicine, University of Costa Rica (UCR), Sede Rodrigo Facio, San Pedro de Montes de Oca, San José 2060, Costa Rica
M. Victoria Moreno-Arribas
Institute of Food Science Research (CIAL), CSIC-UAM, C/ Nicolás Cabrera 9, Madrid 28049, Spain
María Monagas
Institute of Food Science Research (CIAL), CSIC-UAM, C/ Nicolás Cabrera 9, Madrid 28049, Spain
Begoña Bartolomé
Institute of Food Science Research (CIAL), CSIC-UAM, C/ Nicolás Cabrera 9, Madrid 28049, Spain
Apart from alkaloids, bioactive properties of Uncaria tomentosa L. have been attributed to its phenolic constituents. Although there are some reports concerning low-molecular-weight polyphenols in U. tomentosa, its polymeric phenolic composition has been scarcely studied. In this study, phenolic-rich extracts from leaves, stems, bark and wood (n = 14) of Uncaria tomentosa plants from several regions of Costa Rica were obtained and analysed in respect to their proanthocyanidin profile determined by a quadrupole-time-of-flight analyser (ESI-QTOF MS). Main structural characteristics found for U. tomentosa proanthocyanidins were: (a) monomer composition, including pure procyanidins (only composed of (epi)catechin units) and propelargonidins (only composed of (epi)afzelechin units) as well as mixed proanthocyanidins; and (b) degree of polymerization, from 3 up to 11 units. In addition, U. tomentosa phenolic extracts were found to exhibit reasonable antioxidant capacity (ORAC (Oxygen Radical Absorbance Capacity) values between 1.5 and 18.8 mmol TE/g) and antimicrobial activity against potential respiratory pathogens (minimum IC50 of 133 µg/mL). There were also found to be particularly cytotoxic to gastric adenocarcinoma AGS and colon adenocarcinoma SW620 cell lines. The results state the particularities of U. tomentosa proanthocyanidins and suggest the potential value of these extracts with prospective use as functional ingredients.