Despite the numerous advances in modern medicine, cancer and bacterial diseases cause the death of 10 and 11 million people every year globally, respectively. Due to the significant heterogeneity associated with carcinogenesis and the constant emergence of resistant bacterial strains caused by the misuse of antibiotics, the search for new compounds of natural origin with bioactive properties related to tumor and bacterial diseases is growing every year. One of the most relevant compounds found in plants are the secondary metabolites, specifically phenolic compounds. There is vast literature on these molecules and their associated bioactivities, but the establishment of new trials revealing the therapeutic uses of these compounds is continually evolving. In this study, the identification and quantification of phenolic compounds from three species of the Amaranthaceae family (Alternanthera sessilis (L.) R., Dicliptera chinensis (L.) Juss. and Dysphania ambrosioides (L.) Mosyakin & Clemants) were carried out. The results showed a high flavonoid content in the three species, ranging 11.4 – 15.1 mg/g extract, being apigenin, luteolin and isorhamnetin derivates the most abundant compounds. Then, the cytotoxic and antibacterial activities of Amaranthaceae plants extract were determined. Different tumoral cell lines (Caco-2, MCF-7, NCI-H460) were cultivated in the presence of the extracts, and the results revealed high growth inhibitory concentration 50% (GI50) values, ranging from 263 ± 12 to 188 ± 14 µg/mL. In parallel, the antibacterial activity of extracts was assessed against different Gram-positive (Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Proteus mirabilis and Pseudomonas aeruginosa) and Gram-negative (Enterococcus faecalis, Listeria monocytogenes and MRSA) strains. A. sessilis showed minimal inhibitory concentrations (MIC) of 5mg/mL against M. morganii, as well as D. abrosioides, and MRSA strain. These results showed a significant activity of the phenolic compounds present in these three species, exhibiting a high nutraceutical and pharmaceutical potential.

Acknowledgements

The research leading to these results was funded by Xunta de Galicia supporting the Axudas Conecta Peme, the IN852A 2018/58 NeuroFood Project and the program EXCELENCIA-ED431F 2020/12; to Ibero-American Program on Science and Technology (CYTED—AQUA-CIBUS, P317RT0003) and to the Bio Based Industries Joint Undertaking (JU) under grant agreement No 888003 UP4HEALTH Project (H2020-BBI-JTI-2019); by MICINN supporting the Ramón y Cajal grant for M.A. Prieto (RYC-2017-22891); by EcoChestnut Project (Erasmus+ KA202) that supports the work of B. Nuñez-Estevez,. The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Bio Based Industries Consortium. The project SYSTEMIC Knowledge hub on Nutrition and Food Security, has received funding from national research funding parties in Belgium (FWO), France (INRA), Germany (BLE), Italy (MIPAAF), Latvia (IZM), Norway (RCN), Portugal (FCT), and Spain (AEI) in a joint action of JPI HDHL, JPI-OCEANS and FACCE-JPI launched in 2019 under the ERA-NET ERA-HDHL (n° 696295). Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to the CIMO (UIDB/00690/2020). L. Barros and R. Calhelha thank the national funding by FCT, P.I., through the institutional scientific employment program-contract for their contracts.