Bioactive phytonutrients (omega fatty acids, tocopherols, polyphenols), in vitro inhibition of nitric oxide production and free radical scavenging activity of non-cultivated Mediterranean vegetables
Highlights
► The consumption of non-cultivated botanicals play a central role in the diet. ► Twelve-one plant extracts were assayed for antioxidant/anti-inflammatory activity. ► Four extracts were selected for antiradical and anti-inflammatory properties. ► A relationship between radical scavenging activity and polyphenolic content was found.
Introduction
In the contemporary world, often described as a “melting pot”, changing dietary habits might be easier than at any time in the past.
The consumption of non-cultivated botanicals may play a central role in the diet of some population groups, but very few ethnopharmacological and phytopharmacological studies have been exhaustively investigated. Surveys on aromatic species of the traditional Mediterranean cuisine have demonstrated their significant health benefits (Cervato et al., 2000, Lionis et al., 1998).
Epidemiological studies have indicated that dietary intake of antioxidant substances from plants is inversely associated with mortality from coronary heart disease (Giugliano, 2000). Although most antioxidant intake, such as vitamin E, vitamin C, polyphenols, α-carotene, β-carotene, lutein, and zeaxanthin, is from familiar plant sources, there are additional plant sources generally less well-known.
Antioxidant activity was studied in relation to CNS disorders. The metabolism of phospholipids is associated with neuronal death in Alzheimer’s disease (Frölich & Riederer, 1994) and antioxidants such as vitamin E play an important role in β-amyloid aggregation (Murray & Lynch, 1998). Moreover, clinical data show that Alzheimer’s patients obtain remarkable benefits from vitamin E treatment (Sano et al., 1997).
A conventional method for determining the antioxidant activity of edible plants is monitoring the free radical scavenging activity (Parejo et al., 2002). Measurement of radical scavenging activity using discolouration of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH radical scavenging assay) has been widely used due to its stability, simplicity and reproducibility (Kitts, Wijewickreme, & Hu, 2000).
Inflammation is critical in recruiting immune cells and molecules to the site of infection for defence. However, various kinds of tissue damage and pathological consequences ensue when “sterile inflammation”, such as obesity and self-immune diseases, occurs or infection-induced inflammation becomes chronic. Among participating cells, macrophages play a central role in organising the release of inflammation mediators, including prostaglandin E2 (PGE2), nitric oxide (NO) and cytokines that promote host protection, as well as cause pathological consequences such as tissue oedema and abnormal histological change (Wang et al., 2006). The RAW 264.7 mouse macrophage cell line is widely used for studies of inflammation, due to its reproducible response to lipopolysaccharide (LPS), mediated by toll-like receptor 4 (TLR4) (Cao et al., 2006). Our previous research successfully employed the quenching of NO production in LPS-activated RAW 264.7 cells model as a rapid and cost-effective tool for screening the anti-inflammatory activity of extracts of spices/herbs (Menichini et al., 2009). The applicability of this model was further investigated by studying 21 hydroalcoholic extracts (18 species) from non-cultivated and weedy vegetables traditionally consumed by Calabrian people (Southern Italy).
In order to correlate the antioxidant activity of plant extracts with their potential effects on the inflammation process, selected extracts were evaluated for their antioxidant activity using DPPH (1,1-diphenyl-2-picrylhydrazil radical).
Section snippets
Plant material and preparation of crude plant extracts
The different species studied in this work are shown in Table 1, together with some information about their common name, date and site of collection. The collected plants were authenticated by Dr. Uzunov from Botanic Garden, University of Calabria. A voucher is deposited in the Herbarium (CLU) of the Museum of Natural History, University of Calabria. The parts of plant species most commonly gathered in the wild for use in the local gastronomy were collected (Table 2) and dried at room
General
Many of the analysed plants are often present on the table as spice or aromatic condiment, others are used as substitutes to cultivated vegetables. The majority of the wild collected food plants are used raw, as salad, alone or in a mixture (Table 2). For some plants (Foeniculum) more than one part was separately extracted, since different parts are used as food or as herbal drugs. Chicory was collected at different stages of maturation, as it has wide uses in different periods of the year.
Phytochemical content
The
Conclusion
Dietary plants are being recognised as a source of numerous bioactive compounds. Many of them were shown to possess antioxidant properties and inhibit redox-sensitive intracellular signalling pathways leading to cell activation. However, the search for new plants exerting anti-inflammatory properties continues, especially among the plants included in the diets regarded as “health beneficial” ones. Clearly, this research has shown that such local food plants are a treasure trove for developing
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2020, Bioorganic ChemistryCitation Excerpt :The representative constituents, such as alkaloids, triterpenes, lignans, megastigmanes, and flavonoids have been isolated from this plant [2,4]. Some compounds from A. italica or its extract have been found to possess various pharmacological activities including anticancer, antioxidant, antiviral, and memory-enhancing effects [5–9]. Ischemic heart disease is a major cause of morbidity and mortality threatening human health.