Nowadays, numerous diseases still have no cure or there is no effective treatment against them (some cancers, antibiotics-resistant bacterial infections, viruses, among others). To find new treatments for these diseases it is necessary to search for compounds with associated bioactivities of interest. Secondary metabolites from natural sources, such as plants, constitute one of the most relevant pools of molecules with pharmacological potential. In this sense, extracts derived from different species belonging to Amaranthaceae family show relevant effectiveness against several cancer cell lines and pathogenic bacteria under in vitro conditions. In this study, the chemical and nutritional composition of three Amaranthaceae species (Alternanthera sessilis (L.) R.Br. ex Dc, Dicliptera chinensis (L.) Juss., and Dysphania ambrosioides (L.) Mosyakin & Clemants), largely used in Asiatic traditional medicine for the treatment of several diseases, due to its antimicrobial, wound-healing, anti-inflammatory, and antioxidant properties, were studied. Results showed a differential flavonoid content in the three species: A. sessilis and D. ambrosioides showed similar flavonoid contents (15.1 ± 0.6 mg/g extract and 15.1 ± 0.1 mg/g extract, respectively), followed by D. chinensis (11.4 ± 0.1 mg/g extract); however, the principal flavonoids identified in A. sessilis were luteolin derivatives (luteolin-8-C-(rhamnosyl)ketodeoxihexoside and luteolin-6-C-glucoside), in the case of D. ambrosioides were isorhamnetin derivatives (mostly, isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-neohesperidoside), and in D. chinensis were apigenin derivatives (apigenin-6-C-glucoside-8-C-arabinoside and apigenin-2"-O-xyloside-8-C-hexoside). These flavonoids have been reported to have significant bioactive properties, such as anti-inflammatory, anti-proliferative and antioxidant activity in previous studies [1]. On the other hand, the nutritional results showed a high protein content in all the species studied (16.9-13.9 ± 0.1 g/100g dw) and they also revealed the presence of organic acids, such as oxalic and succinic acid. Therefore, the bioactive compounds found in the extracts from Amaranthaceae species could be responsible for the bioactivities attributed to these plants, together with their protein and organic acid content, which could be highly valuable for pharmaceutical, nutraceutical and cosmetic industries.

References

1. Williamson, G.; Kay, C.D.; Crozier, A. The Bioavailability, Transport, and Bioactivity of Dietary Flavonoids: A Review from a Historical Perspective. Compr. Rev. Food Sci. Food Saf. 2018, 17, 1054–1112, doi:10.1111/1541-4337.12351.

Acknowledgments

The research leading to these results was supported by MICINN supporting the Ramón y Cajal grant for M.A. Prieto (RYC-2017-22891); by University of Vigo for supporting the predoctoral grant of M. Carpena (Uvigo-00VI 131H 6410211); by EcoChestnut Project (Erasmus+ KA202) that supports the work of B. Nuñez-Estevez, by Grupos de Referencia Competitiva de la Xunta that supports the work of M. Barral-Martínez (GRUPO AA1-GRC 2018) and by the Bio Based Industries Joint Undertaking (JU) under grant agreement No 888003 UP4HEALTH Project (H2020-BBI-JTI-2019) that supports the work of P. Otero and P. Garcia-Perez. The research leading to these results was funded by Xunta de Galicia supporting the program EXCELENCIA-ED431F 2020/12; to Ibero-American Program on Science and Technology (CYTED—AQUA-CIBUS, P317RT0003). 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). The authors are also gratefull to FCT, Portugal for financial support through national funds FCT/MCTES to the CIMO (UIDB/00690/2020); and L. Barros and R. Calhelha thank the national funding by FCT, P.I., through the institutional and individual scientific employment program-contract for their contracts.