Contribution of Phenolic Compounds to the Antioxidant Activity of Leaf and Flower Extracts of Sinapis pubescens L. subsp. pubescens (Brassicaceae)

Within a study focused on Sinapis pubescens subsp. pubescens wild from Sicily (Italy), an edible species still unexplored, our earlier published work has demonstrated good in vitro antioxidant properties for the flower and leaf hydroalcoholic extracts, exhibiting quite different qualitative-quantitative phenolic profiles. Herein, further research was designed to elucidate the role played by phenolic compounds in the different antioxidant mechanisms highlighted for the extracts. To achieve this goal, the crude extracts were subjected to liquid-liquid partitioning with solvents of increasing polarity; then, the fractions were investigated for their antioxidant properties using different in vitro assays. For both flowers and leaves, the ethyl acetate fractions exhibited the best activity in DPPH and reducing power assays, followed by n-butanol. The total phenolic content determination indicated these fractions as the phenolic-rich ones, which were characterized by HPLC-PDA/ESI-MS analysis. Conversely, the phenolic-rich fractions did not show any chelating activity, which was highlighted for the more hydrophobic ones.

Anthriscus sylvestris-Noxious Weed or Sustainable Source of Bioactive Lignans?

Anthriscus sylvestris (L.) Hoffm. (Apiaceae), commonly known as wild chervil, has gained scientific interest owing to its diverse phytochemical profile and potential therapeutic applications. The plant, despite being categorized as a noxious weed, is traditionally used in treating various conditions like headaches, dressing wounds, and as a tonic, antitussive, antipyretic, analgesic, and diuretic. Its pharmacological importance stems from containing diverse bioactive lignans, especially aryltetralins and dibenzylbutyrolactones. One of the main compounds of A. sylvestris, deoxypodophyllotoxin, among its wide-ranging effects, including antitumor, antiproliferative, antiplatelet aggregation, antiviral, anti-inflammatory, and insecticidal properties, serves as a pivotal precursor to epipodophyllotoxin, crucial in the semisynthesis of cytostatic agents like etoposide and teniposide. The main starting compound for these anticancer medicines was podophyllotoxin, intensively isolated from Sinopodophyllum hexandrum, now listed as an endangered species due to overexploitation. Since new species are being investigated as potential sources, A. sylvestris emerges as a highly promising candidate owing to its abundant lignan content. This review summarizes the current knowledge on A. sylvestris, investigating its biological and morphological characteristics, and pharmacological properties. Emphasizing the biological activities and structure-activity relationship, this review underscores its therapeutic potential, thus encouraging further exploration and utilization of this valuable plant resource.

Chemical Profile and Health-Promoting Activities of Crataegus laciniata (Rosaceae) Flowers

In the present study, we focused our attention on Crataegus laciniata Ucria (Rosaceae), which is wild growing in western Sicily (Italy). The chemical profile of the C. laciniata flower's (CLF) ethanolic (70%) extract showed the presence of both C-flavonoid and O-flavonoid derivatives. Beyond the main metabolites, like hyperoside and vitexin, there are several luteolin derivates, in addition to catechin and epicatechin dimers or trimers. Regarding the antioxidant activities, CLF showed a strong ability to scavenge DPPH and ABTS radicals and a good Fe3+-reducing antioxidant power. The investigation into the key enzymes in diabetes showed strong inhibition on α-amylase and α-glucosidase, whereas the skin-whitening properties are linked to inhibitory effects on tyrosinase. Moreover, we employed Danio rerio (zebrafish) for toxicity assessment, as it represents an ideal in vivo model due to its high correlation with humans in response to pharmaceutical and cosmetic testing. Zebrafish embryos exposed to CLF (25-100 µg/mL) showed marked depigmentation compared to phenylthiourea (PTU), in addition to a high survival percentage and the absence of malformations. In conclusion, this experimental study outlines that C. laciniata flowers could be a potential source of bioactive compounds for application in the pharmaceutical and cosmeceutical industries.

Comparative Study on Phenolic Profile and Biological Activities of the Aerial Parts of Sinapis pubescens L. subsp. pubescens (Brassicaceae) Wild from Sicily (Italy)

This work aimed to investigate Sinapis pubescens subsp. pubescens spontaneously grown in Sicily (Italy) as new potential source of active metabolites; specifically, a comparative study on leaf, flower, and stem hydroalcoholic extracts was performed. Polyphenols were quantitatively determined by spectrophotometric methods and characterized by HPLC-PDA/ESI-MS; a total of 55 polyphenolic compounds were identified, highlighting considerably different qualitative-quantitative profiles. The extracts showed antioxidant activity, evaluated by in vitro assays; particularly, the leaf extract displayed the best radical scavenging activity (DPPH test) and reducing power, while the flower extract showed the greatest chelating activity. The antimicrobial properties of the extracts were investigated against bacteria and yeasts by standard methods; no antimicrobial activity was found against the strains tested. The extracts resulted to be non-toxic after preliminary toxicity evaluation by the Artemia salina lethality bioassay. The aerial parts of S. pubescens subsp. pubescens proved to be valuable sources of antioxidants for pharmaceutical and nutraceutical applications.

Pedoclimatic Conditions Influence the Morphological, Phytochemical and Biological Features of Mentha pulegium L

In this study, Mentha pulegium leaves and flowers harvested in three different Sicilian areas were investigated from a micromorphological, phytochemical and biological point of view. Light and scanning electron microscopy showed the presence of spherocrystalline masses of diosmin both in the leaf epidermal cells and in thin flower petals. Two different chemotypes were identified (I, kaempferide/rosmarinic acid; II, jaceidin isomer A). Phytochemical screening identified plant from collection site II as the richest in total phenolics (16.74 g GAE/100 g DE) and that from collection site I as the richest in flavonoids (46.56 g RE/100 g DE). Seventy-seven metabolites were identified both in flower and leaf extracts. Plant from site II showed the best antioxidant (0.90-83.72 µg/mL) and anti-inflammatory (27.44-196.31 µg/mL) activity expressed as half-maximal inhibitory concentration (IC₅₀) evaluated by DPPH, TEAC, FRAP, ORAC, BSA denaturation and protease inhibition assays. These data were also corroborated by in vitro cell-based assays on lymphocytes and erythrocytes. Moreover, plant of site II showed the best antiangiogenic properties (IC₅₀ 33.43-33.60 µg/mL) in vivo on a chick chorioallantoic membrane. In conclusion, pedoclimatic conditions influence the chemotype and the biological activity of M. pulegium, with chemotype I showing the most promising biological properties.

Biological Investigation and Chemical Study of Brassica villosa subsp. drepanensis (Brassicaeae) Leaves

Brassica villosa subsp. drepanensis (Caruel) Raimondo & Mazzola, belonging to the Brassica oleracea complex, is a wild edible plant endemic to western Sicily and a relative of modern cultivated Brassica crops. In this study, the antioxidant properties, anti-inflammatory activities, enzymatic inhibition, and cytotoxicity in cancer cells of B. villosa subsp. drepanensis leaf ethanolic extract were analysed for the first time. In addition, its chemical profile was investigated partitioning the total 70% ethanol extract among ethyl acetate, n-butanol, and water to obtain three residues that were subjected to chromatographic separation. Two flavonol glycosides, a phenol glucoside, two amino acids, and purine/pyrimidine bases were obtained. The presence of the glucosinolate glucoiberin was detected in the water extract by UHPLC-MS analysis. The total polyphenol and flavonoid content of the 70% ethanol extract showed good antioxidant capacities and anti-inflammatory properties by reducing nitric oxide release and reactive oxygen species levels and increasing glutathione in lipopolysaccharide-stimulated RAW 264.7 cells. The extract inhibited the enzymatic activity of α-amylase, α-glucosidase, and, significantly, of lipase. The MTT assay showed that the extract did not affect the viability of normal HFF-1 and RAW 264.7 cells. Among the cancer cell lines tested, an antiproliferative action was only observed in CaCo-2. The cytotoxicity of the extract was further confirmed by LDH release assay and by the destabilization of the oxidative balance. Results confirmed the antioxidant properties of the crude extract responsible for the anti-inflammatory effect on healthy cells and cytotoxicity in cancer cells.

Phytochemical Constituents, Antioxidant Activity, and Toxicity Assessment of the Aerial Part Extracts from the Infraspecific Taxa of Matthiola fruticulosa (Brassicaceae) Endemic to Sicily

In a project designed to investigate the specific and infraspecific taxa of Matthiola endemic to Sicily (Italy) as new potential sources of bioactive compounds in this work, the infraspecific taxa of Matthiola fruticulosa were studied, namely, subsp. fruticulosa and subsp. coronopifolia. HPLC–PDA/ESI–MS and SPME–GC/MS analyses of hydroalcoholic extracts obtained from the aerial parts of the two subspecies led to the detection of 51 phenolics and 61 volatile components, highlighting a quite different qualitative–quantitative profile. The antioxidant properties of the extracts were explored through in vitro methods: 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power and Fe²⁺ chelating activity assays. The results of the antioxidant tests showed that the extracts possess a different antioxidant ability: particularly, the extract of M. fruticulosa subsp. fruticulosa exhibited higher radical scavenging activity than that of subsp. coronopifolia (IC₅₀ = 1.25 ± 0.02 mg/mL and 2.86 ± 0.05 mg/mL), which in turn displayed better chelating properties (IC₅₀ = 1.49 ± 0.01 mg/mL and 0.63 ± 0.01 mg/mL). Lastly, Artemia salina lethality bioassay was performed for toxicity assessment. The results of the bioassay showed lack of toxicity against brine shrimp larvae for both extracts. The data presented indicate the infraspecific taxa of M. fruticulosa as new and safe sources of antioxidant compounds.

Phytochemical Profile and Antioxidant Activity of the Aerial Part Extracts from Matthiola incana subsp. rupestris and subsp. pulchella (Brassicaceae) Endemic to Sicily

As part of a project aimed at investigating the Matthiola taxa endemic to Sicily (Italy), this study focused on Matthiola incana, an edible species used in the traditional medicine of various countries. Herein, the characterization of phenolic and volatile compounds, the antioxidant capacity in vitro (1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe²⁺ chelating activity assays) and the toxicity test (Artemia salina lethality bioassay) of the hydroalcoholic extracts from the aerial parts of M. incana subsp. rupestris from Mt. Pellegrino (Palermo) and Mt. Erice (Trapani), and of M. incana subsp. pulchella are reported. The results are compared with those previously shown for M. incana subsp. incana, to achieve a comprehensive overview of the three subspecies. The HPLC-PDA/ESI-MS and SPME-GC/MS analyses led to the identification of 13 phenolics and 54 volatile compounds. Differences in the qualitative-quantitative profile of these phytochemicals have been highlighted between the M. incana subspecies. The antioxidant tests showed different activity for the extracts, which were found to possess better chelating properties. At last, none of the tested extracts displayed toxicity against brine shrimp larvae. These findings enrich the knowledge on the Matthiola taxa growing wild in Sicily, both from the strictly systematic point of view and for the possible applications as sources bioactive compounds that can be used in the nutraceutical field.

Mentha pulegium L.: A Plant Underestimated for Its Toxicity to Be Recovered from the Perspective of the Circular Economy

The aim of the study was to investigate the micromorphology of Mentha pulegium leaves and flowers harvested in three different Sicilian (Italy) areas with peculiar pedo-climatic conditions, and to characterize the phytochemical profile, the phytotoxic activity, and the eco-compatibility of their essential oils (EOs) for potential use as safe bioherbicides. Light microscopy (LM) and scanning electron microscopy (SEM) highlighted that M. pulegium indumentum consists of non-glandular and glandular trichomes of different types. Peltate trichomes of plants from the different sites showed few significant differences in dimension and abundance, but they were characterized by a surprisingly high number of secretory cells both in leaves and flowers. Phytochemical analyses showed that oxygenated monoterpenes were the most abundant class in all the EOs investigated (92.2-97.7%), but two different chemotypes, pulegone/isomenthone and piperitone/isomenthone, were found. The complex of morphological and phytochemical data indicates that soil salinity strongly affects the expression of the toxic metabolite pulegone, rather than the EO yield. Phytotoxicity tests showed a moderate activity of EOs against the selected species as confirmed by α-amylase assay. Moreover, the low toxicity on brine shrimp provided a rationale for the possible use of investigated EOs as eco-friendly herbicides.

Preserving Biodiversity in Marginal Rural Areas: Assessment of Morphological and Genetic Variability of a Sicilian Common Bean Germplasm Collection

The historical cultivation of common bean (Phaseolus vulgaris L.) has resulted in the development of local populations/cultivars in restricted Italian rural areas. Many common bean landraces, still cultivated in small mountain areas from Sicily, have become outdated and endangered due to the commercial varieties spreading. These accessions are poorly known but often represent a genetic heritage to be preserved and enhanced. The ex situ conservation of fifty-seven Sicilian common bean landraces was carried out at the "Living Plants Germplasm Bank" at Ucria (Messina, Italy), founded by the Nebrodi Regional Park, together with the "Sicilian Plant Germplasm Repository" of University of Palermo (SPGR/PA). To assess the germplasm genetic diversity, nineteen morphological traits and eight Simple Sequence Repeats (SSRs) were used. Genetic distances among landraces were calculated to construct a clustering tree by using unweighted pair group method arithmetic (UPGMA). Seed germplasm diversity of Sicilian common bean varied from 80.7% to 93.3%, based on six seed descriptors and six leaf, flower, and pod descriptors, respectively, while cluster genetic analysis depicted a clear separation among all the 57 landraces. Principal coordinates (PCoA) and STRUCTURE analyses showed a prevalent rate of admixture between Mesoamerican and Andean gene pools in Sicilian common bean collection, confirming its heterogeneity. The observed high level of diversity evidenced the needs to adopt accurate criterion to plan a definitive ex situ germplasm collection to share agrobiodiversity with local farmers and to avoid any further loss of genetic resources in rural and protected areas.

Polyphenol Characterization, Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark

In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel.) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP-LC-DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose-dependent antioxidant and free-radical scavenging activity, expressed as half-maximal inhibitory concentration (IC₅₀ ): Oxygen radical absorbance capacity (ORAC, IC₅₀ 1.78 μg mL^-1 )>Trolox equivalent antioxidant capacity (TEAC, IC₅₀ 3.47 μg mL^-1 )>2,2-Diphenyl-1-picrylhydrazyl (DPPH, IC₅₀ 5.83 μg mL^-1 )>β-carotene bleaching (IC₅₀ 11.58 μg mL^-1 )>Ferric reducing antioxidant power (FRAP, IC₅₀ 17.28 μg mL^-1 ). Moreover, ACE was able to inhibit in vitro tyrosinase activity (IC₅₀ 77.44 μg mL^-1 ), l-DOPA auto-oxidation (IC₅₀ 39.58 μg mL^-1 ) and in an in vivo model it exhibited bleaching effects on the pigmentation of zebrafish embryos (72 h post fertilization) without affecting their development and survival. In conclusion, results show that A. cordata stem bark may be considered a potential source of agents for the treatment of skin disorders due to its bleaching properties and favorable safety profiles, associated to a good antioxidant power.

Metabolites from the Aerial Parts of the Sicilian Population of Artemisia alba

Phytochemical investigation of the CH2Cl2 extract of the aerial parts of Artemisia alba Turra afforded one new irregular sesquiterpenoid, artemiric acid, and five known metabolites: hydroxydavanone, the coumarins isofraxidin and scopoletin, (6 S*,7 S*,10 R*)–6,10-dimethyl-7,10-epoxyocta-11-enoic acid and artalbic acid. From the MeOH extract three flavonoids were identified: chrysoeriol, quercetin and isorhamnetin. The possible biogenetic pathways of artemiric and artalbic acids are discussed.

Metabolites from the aerial parts of the Sicilian population of Artemisia alba

Phytochemical investigation of the CH2Cl2 extract of the aerial parts of Artemisia alba Turra afforded one new irregular sesquiterpenoid, artemiric acid, and five known metabolites: hydroxydavanone, the coumarins isofraxidin and scopoletin, (6S*, 7S*,10R*)-6,10 -dimethyl-7,10-epoxyocta-11-enoic acid and artalbic acid. From the MeOH extract three flavonoids were identified: chrysoeriol, quercetin and isorhamnetin. The possible biogenetic pathways of artemiric and artalbic acids are discussed.

Essential Oil Composition and Antibacterial Activity of Anthemis mixta and A. Tomentosa(Asteraceae)

In the present study the chemical composition of the essential oils from aerial parts and roots of Anthemis mixta L. and A. tomentosa L. was evaluated by GC and GC-MS, and their antibacterial activity tested against ten bacterial species. Hexadecanoic acid (15.2%) was recognized as the main constituent of A. mixta, together with τ-cadinol (6.7%), while in both aerial parts and roots of A. tomentosa nonacosane (21.9% and 20.7%), heptacosane (8.1% and 6.0%), hexadecanoic acid (8.1% and 27.1%) and hexahydrofarnesylacetone (6.8% and 5.5%) prevailed. The oils from aerial parts of both species showed a good activity against Gram-positive bacteria. These results suggest that the plants could be potentially used in food manufacture and cosmetology as preservative agents or in medicine as new antibiotics.

Essential oil composition and antibacterial activity of Anthemis mixta and A. tomentosa (Asteraceae)

In the present study the chemical composition of the essential oils from aerial parts and roots of Anthemis mixta L. and A. tomentosa L. was evaluated by GC and GC-MS, and their antibacterial activity tested against ten bacterial species. Hexadecanoic acid (15.2%) was recognized as the main constituent ofA. mixta, together with tau-cadinol (6.7%), while in both aerial parts and roots of A. tomentosa nonacosane (21.9% and 20.7%), heptacosane (8.1% and 6.0%), hexadecanoic acid (8.1% and 27.1%) and hexahydrofarnesylacetone (6.8% and 5.5%) prevailed. The oils from aerial parts of both species showed a good activity against Gram-positive bacteria. These results suggest that the plants could be potentially used in food manufacture and cosmetology as preservative agents or in medicine as new antibiotics.

Chemical composition of essential oil from Italian populations of Artemisia alba Turra (Asteraceae)

The use of essential oils as chemotaxonomic markers could be useful for the classification of Artemisia species and to caracterize biodiversity in the different populations. An analysis of the chemical composition of four essential oils from Italian populations of Artemisia alba Turra (collected in Sicily, Marche and Abruzzo) was investigated. In this paper an in depth study of the significant differences observed in the composition of these oils is reported.

Cytotoxic effect of eudesmanolides isolated from flowers of Tanacetum vulgare ssp. siculum

A phytochemical analysis of the dichloromethane extract from the flowers of a subspecies of Tanacetum vulgare growing in Sicily was carried out. Five known sesquiterpene lactones with the eudesmane skeleton have been isolated and the cytotoxic activity of these compounds was tested in vitro on A549 (human lung carcinoma epithelial-like) and V79379A (Chinese hamster lung fibroblast-like) cells using the tetrazolium salt reduction (MTT) assay. All of tested compounds induced high time- and concentration-dependent cytotoxic effects.

Chemical Composition of the Essential Oils of Centaurea Sicana and C. Giardinae Growing Wild in Sicily

The essential oils of Centaurea sicana (S) and C. giardinae (G) were studied by GC and GC-MS. Thirty constituents for S, representing 81.5% of the total oil, and 24 compounds for G (94.2% of the total) were identified. The oils were rich in sesquiterpenoids (47.9% for S and 54.7% for G) and hydrocarbons (25.9% for S and 31.7% for G). Germacrene D (13.3%), ( E)-β-farnesene (8.3%), nonacosane (7.3%), heptacosane (6.5%) and phytol (6%) were recognized as the main constituents for S, while caryophyllene oxide (17.7%), nonacosane (14.5%), germacrene D (11.5%), caryophyllene (11.2%) and heptacosane (10.3%) were the main compounds for G.