Proanthocyanidin Characterization, Antioxidant and Cytotoxic Activities of Three Plants Commonly Used in Traditional Medicine in Costa Rica: Petiveria alliaceae L., Phyllanthus niruri L. and Senna reticulata Willd.

Plants (Basel). 2017 Oct 19;6(4). pii: E50. doi: 10.3390/plants6040050. Navarro M1, Moreira I2, Arnaez E3, Quesada S4, Azofeifa G5, Alvarado D6, Monagas MJ7. Author information 1 Department of Chemistry, University of Costa Rica (UCR), Rodrigo Facio Campus, San Pedro Montes Oca, San Jose 2060, Costa Rica. mnavarro@codeti.org. 2 Department of Biology, Technological University of Costa Rica (TEC), Cartago 7050, Costa Rica. imoreira@itcr.ac.cr. 3 Department of Biology, Technological University of Costa Rica (TEC), Cartago 7050, Costa Rica. earnaez@itcr.ac.cr. 4 Department of Biochemistry, School of Medicine, University of Costa Rica (UCR), Rodrigo Facio Campus, San Pedro Montes Oca, San Jose 2060, Costa Rica. silvia.quesada@ucr.ac.cr. 5 Department of Biochemistry, School of Medicine, University of Costa Rica (UCR), Rodrigo Facio Campus, San Pedro Montes Oca, San Jose 2060, Costa Rica. gabriela.azofeifacordero@ucr.ac.cr. 6 Department of Biology, University of Costa Rica (UCR), Rodrigo Facio Campus, San Pedro Montes Oca, San Jose 2060, Costa Rica. luis.alvaradocorella@ucr.ac.cr. 7 Institute of Food Science Research (CIAL), Spanish National Research Council (CSIC-UAM), C/Nicolas Cabrera 9, 28049 Madrid, Spain. mjm@usp.org. Abstract The phenolic composition of aerial parts from Petiveria alliaceae L., Phyllanthus niruri L. and Senna reticulata Willd., species commonly used in Costa Rica as traditional medicines, was studied using UPLC-ESI-TQ-MS on enriched-phenolic extracts. Comparatively, higher values of total phenolic content (TPC), as measured by the Folin-Ciocalteau method, were observed for P. niruri extracts (328.8 gallic acid equivalents/g) than for S. reticulata (79.30 gallic acid equivalents/g) whereas P. alliaceae extract showed the lowest value (13.45 gallic acid equivalents/g). A total of 20 phenolic acids and proanthocyanidins were identified in the extracts, including hydroxybenzoic acids (benzoic, 4-hydroxybenzoic, gallic, prochatechuic, salicylic, syringic and vanillic acids); hydroxycinnamic acids (caffeic, ferulic, and p-coumaric acids); and flavan-3-ols monomers [(+)-catechin and (-)-epicatechin)]. Regarding proanthocyanidin oligomers, five procyanidin dimers (B1, B2, B3, B4, and B5) and one trimer (T2) are reported for the first time in P. niruri, as well as two propelargonidin dimers in S. reticulata. Additionally, P. niruri showed the highest antioxidant DPPH and ORAC values (IC50 of 6.4 μg/mL and 6.5 mmol TE/g respectively), followed by S. reticulata (IC50 of 72.9 μg/mL and 2.68 mmol TE/g respectively) and P. alliaceae extract (IC50 >1000 μg/mL and 1.32 mmol TE/g respectively). Finally, cytotoxicity and selectivity on gastric AGS and colon SW20 adenocarcinoma cell lines were evaluated and the best values were also found for P. niruri (SI = 2.8), followed by S. reticulata (SI = 2.5). Therefore, these results suggest that extracts containing higher proanthocyanidin content also show higher bioactivities. Significant positive correlation was found between TPC and ORAC (R² = 0.996) as well as between phenolic content as measured by UPLC-DAD and ORAC (R² = 0.990). These findings show evidence for the first time of the diversity of phenolic acids in P. alliaceae and S. reticulata, and the presence of proanthocyanidins as minor components in latter species. Of particular relevance is the occurrence of proanthocyanidin oligomers in phenolic extracts from P. niruri and their potential bioactivity. KEYWORDS: P. alliaceae; P. niruri; S. reticulata; TQ-ESI-MS; UPLC; antioxidant; cytotoxicity; mass spectrometry; proanthocyanidins PMID: 29048336 PMCID: PMC5750626 DOI: 10.3390/plants6040050 Free PMC Article - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5750626/