Exploring salt tolerant plants as sources of innovative food additives

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Greener is better: first approach for the use of natural deep eutectic solvents (NADES) to extract antioxidants from the medicinal halophyte Ppolygonum maritimum L.

Publication . Rukavina, Iva; Rodrigues, Maria João; Pereira, Catarina; Mansinhos, Inês; Romano, Anabela; Ślusarczyk, Sylwester; Matkowski, Adam; Custódio, Luísa

In this study, natural deep eutectic solvents (NADES) formed by choline chloride (ChCl), su crose, fructose, glucose, and xylose, were used to extract antioxidants from the halophyte Polygonum maritimum L. (sea knotgrass) and compared with conventional solvents (ethanol and acetone). NADES and conventional extracts were made by an ultrasound-assisted procedure and evaluated for in vitro antioxidant properties by the radical scavenging activity (RSA) on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, oxygen radical absorbance capacity (ORAC), and cop per chelating activity (CCA). Samples were profiled by liquid chromatography (LC)-electrospray ionization (ESI)-QTOF-MS analysis. ChCl:fructose was more efficient in the DPPH assay, than the acetone extract. ChCl:sucrose and ChCl:fructose extracts had the highest ORAC when compared with the acetone extract. NADES extracts had higher CCA, than the acetone extract. The phenolic composition of the NADES extracts was less complex than the conventional extracts, but the pro portions of major antioxidants, such as flavonols and flavan-3-ols, were similar in all the solvents. Myricitrin was the major flavonoid in all of the samples, while gallic acid was the main phenolic acid in the conventional extracts and present in a greater amount in ChCl:fructose. Results suggest that NADES containing ChCl and sucrose/fructose can replace conventional solvents, especially acetone, in the extraction of antioxidants from sea knotgrass.

2021-10Journal article

Open Access

Antigenotoxic properties of the halophyte Polygonum maritimum L. highlight its potential to mitigate oxidative stress-related damage

Publication . Oliveira, Daniela; Dias, Maria Inês; Barros, Lillian; Custódio, Luísa; Oliveira, Rui

Long-term exposure to dietary xenobiotics can induce oxidative stress in the gastrointestinal tract, possibly causing DNA damage and contributing to the initiation of carcinogenesis. Halophytes are exposed to constant abiotic stresses, which are believed to promote the accumulation of antioxidant metabolites like polyphenols. The aim of this study was to evaluate the antioxidant and antigenotoxic properties of the ethanol extract of the aerial part of the halophyte Polygonum maritimum L. (PME), which can represent a dietary source of bioactive compounds with potential to attenuate oxidative stress-related damage. The PME exhibited a high antioxidant potential, revealed by the in vitro capacity to scavenge the free radical DPPH (IC50 = 2.29 +/- 0.10 mu g/mL) and the improved viability of the yeast Saccharomyces cerevisiae under oxidative stress (p < 0.001, 10 min). An antigenotoxic effect of PME against H2O2-induced oxidative stress was found in S. cerevisiae (p < 0.05) with the dominant deletion assay. In vitro colorimetric assays and LC-DAD-ESI/MSn analysis showed that PME is a polyphenol-rich extract composed of catechin, (epi)catechin dimer and trimers, quercetin and myricetin glycosides. Hence, P. maritimum is a source of antioxidant and antigenotoxic metabolites for application in industries that develop products to provide health benefits.

2023-03Journal article

Open Access

Harnessing the bioactive potential of Limonium spathulatum (Desf.) Kuntze: insights into enzyme inhibition and phytochemical profile

Publication . Youssef, Seria; Custódio, Luísa; Rodrigues, Maria João; Pereira, Catarina; Calhelha, Ricardo C.; Jekő, József; Cziáky, Zoltán; Ben Hamed, Karim

This study assessed the halophyte species Limonium spathulatum (Desf.) as a possible source of natural ingredients with the capacity to inhibit enzymes related to relevant human health disorders and food browning. Extracts using food-grade solvents such as water and ethanol were prepared by maceration from dried L. spathulatum leaves. They were evaluated for in vitro inhibition activity of enzymes such as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), α-glucosidase, tyrosinase and lipase, related to Alzheimer’s disease, type-2-diabetes mellitus, skin hyperpigmentation, and obesity, respectively. These extracts were also appraised for in vitro acute toxicity on tumoral and non-tumoral cell lines and their chemical composition by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS). The extracts were more effective towards BChE than AChE. The best results were obtained with the hydroethanolic and water extracts, with IC₅₀ values of 0.03 mg/mL and 0.06 mg/mL, respectively. The hydroethanolic extract had the highest capacity to inhibit α-glucosidase (IC₅₀: 0.04 mg/mL), higher than the positive control used (acarbose, IC₅₀ = 3.14 mg/mL). The ethanol extract displayed the best inhibitory activity against tyrosinase (IC₅₀ = 0.34 mg/mL). The tested samples did not inhibit lipase and exhibited low to moderate cytotoxic activity against the tested cell lines. The hydroethanolic extract had a higher diversity of compounds, followed by the ethanol and water samples. Similar molecules were identified in all the extracts and were mainly hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids. Taken together, these results suggest that L. spathulatum should be further explored as a source of bioactive ingredients for the food, cosmetic, and pharmaceutical industries.

2023-09-26Journal article

Open Access

From threat to opportunity: Harnessing the invasive Carpobrotus edulis (L.) N.E.Br for nutritional and phytotherapeutic valorization amid seasonal and spatial variability

Publication . Pereira, Catarina Guerreiro; Neng, Nuno R.; Custódio, Luísa

Carpobrotus edulis (L.) N.E.Br. (Hottentot-fig) is a problematic invasive species found in coastal areas worldwide. Mechanical removal is a common control method, leaving the removed biomass available as a possible source of natural phytochemicals with prospective commercial applications. While the Hottentot-fig’s vegetative organs have been studied previously, this work establishes for the first time a seasonal and spatial comparative analysis of its nutritional, chemical, and bioactivity profiles (in three locations over four seasons). Proximate and mineral contents were assessed, along with its phenolic composition and in vitro antioxidant and anti-inflammatory properties. Hottentot-fig’s biomass offered a good supply of nutrients, mainly carbohydrates, proteins, and minerals, with a tendency for higher concentrations of the most relevant minerals and proteins in autumn and winter, and in plants from sites A (Ria de Alvor lagoon) and B (Ancão beach). The extracts were rich in polyphenolics, with higher levels in spring and summer, especially for luteolin7-O-glucoside and salicylic and coumaric acids. The extracts were also effective antioxidants, with stronger radical scavenging activities in spring and summer, along with anti-inflammatory properties. Our results suggest that the usually discarded plant material of this invasive halophyte could be valuable as a source of natural products with potential biotechnological applications in the food and nutraceutical industries.

2023-08-01Journal article

Open Access

Protective properties of the edible halophyte Carpobrotus edulis (L.) N.E.Br. towards neoformed food contaminants-related oxidative stress and genotoxicity

Publication . Oliveira, Daniela; Hayrapetyan, Ruzanna; Dias, Maria Inês; Barros, Lillian; Séverin, Isabelle; Custódio, Luísa; Chagnon, Marie-Christine; Oliveira, Rui

Carpobrotus edulis (L.) N.E.Br. is an edible halophyte native to South Africa, where it has been traditionally consumed as food, revealing its nutritional value, and used in the treatment of human diseases probably due to the accumulation of bioactive compounds such as polyphenols. These compounds have potential to display valuable biological activities that could bring several benefits to the human being, including the mitigation of toxicity induced by food contaminants. Therefore, this study investigated biological activities with healthpromoting potential of a C. edulis ethanol extract (CEE), such as antioxidant, antigenotoxic, and antimutagenic. CEE was shown by LC-DAD-ESI/MSn to be composed of 16 polyphenols. The extract exhibited antioxidant properties by protecting Saccharomyces cerevisiae viability and improving the redox state of HepG2 cells under oxidative stress. Antigenotoxicity of CEE against H2O2-induced oxidative damage was detected in HepG2 and Caco-2 cells by comet assay and subsequently observed in the dominant deletion assay in S. cerevisiae. Antigenotoxicity and antimutagenicity of CEE towards the neoformed contaminant benzo[a]pyrene was found in HepG2 and Caco-2 cells by comet assay and in Salmonella typhimurium using the Ames test, respectively. The disclosed antigenotoxic and antimutagenic properties of C. edulis further advance its potential for application in food and nutraceutical industries for health benefits.

2024-10Journal article

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