Advisor(s)
Abstract(s)
Since the beginning of the 21st century, food products have been subjected to numerous tests to check their quality and presence of harmful agents. Nowadays, consumers awareness about food quality has increased dramatically, paying much attention to the identification of artificial additives, which are normally included as preservative ingredients, among others. This change is also represented in the food industry, where the use of natural food texturizers and preservatives has been replacing some commonly used artificial additives, thus motivating the search for new bioactive compounds from natural sources. Among such bioactive compounds, plant secondary metabolites, in special phenolic compounds, have been largely reported for their health-enhancing properties and preservative effect. In this study, a phytochemical and nutritional characterization of three species from the Amaranthaceae family (Alternanthera sessilis (L.) R., Dicliptera chinensis (L.) Juss. and Dysphania ambrosioides (L.) Mosyakin & Clemants) was performed. The antioxidant and antimicrobial activities and cytotoxicity to tumour and non-tumour cell lines were also evaluated using different methodologies. The results showed a high content of flavonoids in the ethanolic extract of the three species, ranging 11.4 – 15.1 mg/g extract, with apigenin, luteolin and isorhamnetin derivatives being the most abundant compounds. On the other hand, the results from nutritional analysis showed a high protein content in the species studied (13.9- 16.9 ± 0.1 g/100 g of dry weight, dw), together with the presence of organic acids, such as oxalic and succinic acids. Concerning the reported bioactivities of the plant extracts, the results for cytotoxic activity showed GI50 values ranging from 263 ± 12 μg/mL to 188 ± 14 μg/mL towards different tumor cell lines (colon carcinoma, Caco-2; breast adenocarcinoma, MCF-7; and non-small cell lung, NCI-H460) and no cytotoxic activity in the control cell line (Vero). Moreover, with respect to antimicrobial activity, the A. sessilis extract showed minimal inhibitory concentrations (MIC) of 5 mg/mL against Morganella morganii, as well as the D. abrosioides extract against methicillin-resistant Staphylococcus aureus (MRSA). For the antioxidant activity determined by the oxidative haemolysis assay (OxHLIA), the D. abrosioides extract showed an IC50 of 66 ± 10 μg/mL. Overall, these results suggest that ethanolic extracts from the characterized Amaranthaceae species, exhibiting a high bioactive potential, can be considered as promising natural ingredients or additives in the food industry.
Description
Keywords
Amaranthaceae plants Antioxidant activity
Citation
Nuñez-Estevez, B.; Finimundy, Tiane C.; Carpena, Maria; Otero, Paz; Barral-Marinez, M.; Pires, Tânia C.S.P.; Mandim, Filipa; Pinela, José; Garcia-Perez, P.; Simal-Gandara, Jesus; Ferreira, Isabel C.F.R.; Prieto Lage, Miguel A.; Barros, Lillian (2021). Antimicrobial, cytotoxic and antioxidante activity of Amaranthaceae plants: a renewable source of nutrients and phenolic compounds. In XV Encontro de Química dos Alimentos. Funchal. ISBN 978-989-8805-68-3