Phenolic composition, antioxidant capacity, energy content and gastrointestinal stability of Croatian wild edible plants

The Effect of Lactiplantibacillus plantarum I-Enriched Diet on the Phenolic Content and Antioxidant Capacity of Queen Scallop (Aequipecten opercularis Linnaeus, 1758) Extracts

The use of probiotics in the diet of bivalves poses a great potential in aquaculture as an alternative to antibiotics. The aim of this study was to assess the effect of Lactiplantibacillus plantarum I on the phenolic content and antioxidant capacity (AC) of queen scallop extracts after one month of feeding. Total phenols (TP) ranged from 28.17 ± 3.11 to 58.58 ± 8.57 mg GAE/100 g, total non-flavonoids (TNF) from 23.33 ± 3.66 to 36.56 ± 9.91 mg GAE/100 g, and total flavonoids (TF) from 10.56 ± 5.57 to 30.16 ± 1.69 mg CE/100 g. AC was assessed via three different methods: the ferric-reducing ability of plasma assay (FRAP), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic) acid assay (ABTS), and 2,2-diphenyl-1-picryhydrazyl assay (DPPH). FRAP values ranged from 0.13 ± 0.03 to 0.17 ± 0.02 µM AA/g, ABTS from 0.68 ± 0.11 to 2.79 ± 0.34 µM AA/g, and DPPH from 1.75 ± 0.17 to 2.98 ± 0.53 µM AA/g. Among all extracts, the best phenolic content and AC were observed in water extracts from queen scallops. The bivalves treated with the Lactiplantibacillus plantarum I-enriched diet showed higher AC according to the FRAP assay in all extracts. A significant correlation was observed between AC and TP and TNF in control and Lactiplantibacillus plantarum I-treated scallops.

Wild Asparagus Shoots Constitute a Healthy Source of Bioactive Compounds

Wild Asparagus shoots are consumed worldwide, although most species remain understudied. In this work, a total of four wild Asparagus species were collected from different locations and analyzed compared with farmed A. officinalis. Shoots were screened for (i) phenolic compounds by HPLC-DAD and LC-MS; (ii) total phenolic acids and total flavonoid content by the Folin-Ciocalteu and aluminum chloride methods; (iii) vitamin C by HPLC-DAD; (iv) antioxidant activity by the DPPH and ABTS•+ methods; and (v) the in vitro antiproliferative activities against HT-29 colorectal cancer cells by the MTT assay. Phenolics ranged from 107.5 (A. aphyllus) to 605.4 mg/100 g dry weight (dw) (A. horridus). Vitamin C ranged from 15.8 (A. acutifolius) to 22.7 mg/100 g fresh weight (fw) (A. officinalis). The antioxidant activity was similar in all species, standing out in A. officinalis with 5.94 (DPPH) and 4.64 (ABTS) mmol TE/100 g dw. Among phenolics, rutin reached the highest values (574 mg/100 g dw in A. officinalis), followed by quercetin, nicotiflorin, asterin, and narcissin. The MTT assay revealed the inhibitory effects of ethanol extracts against HT-29 cancer cells, highlighting the cell growth inhibition exercised by A. albus (300 µg/mL after 72 h exposure to cells). This work improves knowledge on the phytochemicals and bioactivities of the shoots of wild Asparagus species and confirms their suitability for use as functional foods.

Invasive Alien Species as a Potential Source of Phytopharmaceuticals: Phenolic Composition and Antimicrobial and Cytotoxic Activity of Robinia pseudoacacia L. Leaf and Flower Extracts

Black locust (Robinia pseudoacacia L.), an invasive tree in Europe, commonly known for its negative impact on biodiversity, is a rich source of phenolic compounds recognized in traditional medicine. Since the metabolite profile depends on the environment and climate, this study aimed to provide the first LC-MS phytochemical screening of the black locust from the Istria region (Croatia). The compounds were extracted from leaves and flowers with 70% ethanol and 80% methanol. Total phenolics (TP) and flavonoids (TF), as well as antioxidant capacity (AC) measured by ABTS (17.49-146.41 mg TE/g DW), DPPH (24.67-118.49 mg TE/g DW), and FRAP (7.38-77.53 mg TE/g DW) assays, were higher in leaf than in flower extracts. Higher TP and total non-flavonoid (TNF) values were displayed in ethanolic than in methanolic extracts. In total, 64 compounds were identified, of which flavonols (20) and hydroxycinnamic acid derivatives (15) were the most represented. Flavanols such as catechin dominated in leaf extracts, followed by flavonols, with kaempferol glucuronyl rhamnosyl hexosides as the main compound, respectively. Flower extracts had the highest share of flavones, followed by ellagitannins, with luteolin dirhamnosyl hexosides and vescalagin, respectively, being predominant. The extracts had good quorum sensing, biofilm formation prevention, and eradicating capacity. The results provided new insights into the phytochemical properties of R. pseudoacacia as the first step toward its potential pharmaceutical use.

Carbazole-based semicarbazones and hydrazones as multifunctional anti-Alzheimer agents

With the aim to combat a multi-faceted neurodegenerative Alzheimer's disease (AD), a series of carbazole-based semicarbazide and hydrazide derivatives were designed, synthesized and assessed for their cholinesterase (ChE) inhibitory, antioxidant and biometal chelating activity. Among them, (E)-2-((9-ethyl-9H-carbazol-3-yl)methylene)-N-(pyridin-2-yl)hydrazinecarbothioamide (62) and (E)-2-((9-ethyl-9H-carbazol-3-yl)methylene)-N-(5-chloropyridin-2-yl)hydrazinecarbothioamide (63) emerged as the premier candidates with good ChE inhibitory activities (IC₅₀ values of 1.37 µM and 1.18 µM for hAChE, IC₅₀ values of 2.69 µM and 3.31 µM for EqBuChE, respectively). All the test compounds displayed excellent antioxidant activity (reduction percentage of DPPH values for compounds (62) and (63) were 85.67% and 84.49%, respectively at 100 µM concentration). Compounds (62) and (63) conferred specific copper ion chelating property in metal chelation study. Molecular docking studies of compounds (62) and (63) indicate strong interactions within the active sites of both the ChE enzymes. Besides that, these compounds also exhibited significant in silico drug-like pharmacokinetic properties. Thus, taken together, they can serve as a starting point in the designing of multifunctional ligands in pursuit of potential anti-AD agents that might further prevent the progression of ADs.Communicated by Ramaswamy H. Sarma.

Hybrid molecules based on caffeic acid as potential therapeutics: A focused review

Caffeic acid-based compounds possess a high degree of structural diversity and show a variety of pharmacological properties, providing a useful framework for the discovery of new therapeutic agents. They are well-known analogues of antioxidants found in many natural products and synthetic compounds. The present review surveys the recent developments in structure-activity relationships (SAR) and mechanism of action (MOA) of various caffeic acid-containing compounds that play important roles in the design and synthesis of new bioactive molecules with antioxidant, antidiabetic, antiviral, antibacterial, anticancer, anti-inflammatory, and other properties. This review should provide inspiration to scientists in the research fields of organic synthesis and medicinal chemistry related to the development of new antioxidants with versatile therapeutic potential.

Biopotential of Underutilized Rosaceae Inflorescences: LC-DAD-MS Phytochemical Profiles Associated with Antioxidant, Antidiabetic, Anti-Inflammatory and Antiproliferative Activity In Vitro

The aim of this work was to assess the biopotential of the young inflorescence tissues of Prunus, Malus and Chaenomeles in order to evaluate the possibility of their application in the food industry, and to provide a polyphenolic fingerprint for their quality control. The contents of different bioactive compounds and their antioxidant capacities were spectrophotometrically measured, the main phenolic compounds were identified and quantified using LC-DAD-MS, the antidiabetic potential was determined using α-amylase and α-glucosidase inhibition assays, the anti-inflammatory potential was determined using a 5-lipoxygenase inhibition assay, and the cytotoxicity was determined by MTT assay. Using one-way ANOVA, principal component analysis, hierarchical clustering and Pearson’s correlation coefficient, the relations between the samples, and between the samples and the measured parameters, were revealed. In total, 77 compounds were identified. The concentration of sugars was low in M. purpurea, at 1.56 ± 0.08 mg/g DW. The most effective sample in the inhibition of antidiabetic enzymes and anti-inflammatory 5-lipoxygenase was C. japonica. The inhibition of α-glucosidase was strongly positively correlated with the total and condensed tannins, procyanidin dimers and procyanidin tetramer, and was very strongly correlated with chlorogenic acid. In α-amylase inhibition, C. japonica and P. serrulata ‘Kiku Shidare Zakura’ were equally efficient to the standard inhibitor, maltose. The most effective in the growth and proliferation inhibition of HepG2, HCT116 and HaCaT cells was P. avium. The results suggest Prunus, Malus and Chaenomeles inflorescences as functional food ingredients.

Antiproliferative and pro-apoptotic activities of wild asparagus (Asparagus acutifolius L.), black bryony (Tamus communis L.) and butcher's broom (Ruscus aculeatus L.) aqueous extracts against T24 and A549 cancer cell lines

The aim of this study was to determine the phenolic profile, antiproliferative, and pro-apoptotic activities of Asparagus acutifolius, Tamus communis, and Ruscus aculeatus aqueous extracts against human bladder (T24) and lung cancer (A549) cell lines. Antiproliferative activity of the extracts at the concentration range from 0.5 to 4 mg/ml was measured by MTT test, after the incubation period of 4, 24, 48, or 72 hr. Pro-apoptotic activity of selected plant extracts against T24 and A549 cells was analyzed by flow cytometry at the concentrations of 0.5, 1, and 2 mg/ml. The highest antiproliferative activity against both cancer cell lines was detected by T. communis aqueous extract. The highest pro-apoptotic effect was achieved by A. acutifolius aqueous extract and its effect was similar against A549 and T24 cells. PRACTICAL APPLICATIONS: Wild edible plants, such as wild asparagus, black bryony, and butcher's broom represent important aspect of the Mediterranean diet. They are rich source of various natural bioactive compounds which express different biological activities (antioxidative, antiproliferative, antibacterial, anti-inflammatory…). The current trend for natural and healthy diet, such as the Mediterranean diet, is in relation to the rapidly growing problem of chronic diseases in a modern society. Wild edible plants have a high direct-use value using them in dishes containing mixed vegetables, in soup preparation, as natural additives in fermented natural products containing cheese or fish, in water infusions (natural drinks).

Comparative Analysis of Native Crocus Taxa as a Great Source of Flavonoids with High Antioxidant Activity

Native Crocus taxa are abundant in regions with moderate and dry climate; however, their potential in the food industry has thus far been neglected. The objective of this study was to compare the quantitative and qualitative flavonoid content and antioxidant and cytotoxic activity in organs of several populations of Croatian native taxa and assess their potential for application in the food industry. The dominant flavonoids in the native Crocus taxa were kaempferol and quercetin. Tepals contained similar or higher concentrations of flavonoid-glycosides than other organs. Tepals from Cvv1 and Cvv2 populations contained more flavonoid-glycosides than the commonly used spice saffron (C. sativus stigmas). The FRAP antioxidant activity of Cvv1 and Cvv5 tepals was similar to that of standard Trolox. DPPH inhibition of Cvv1 and Cvv3 tepals was within the range of that recorded for saffron. Cvv1 tepals significantly reduced reactive oxygen species in the broadest concentration range (50-1000 μg/ml), and showed considerable antioxidant activity in the ABTS assay, equal to 82% of standard Trolox antioxidant activity. A significantly higher concentration of kaempferol-rutinoside was recorded in this than in other taxa. The flavonoid showed a very strong or strong correlation with antioxidant assays results, and a negative correlation with cellular reactive oxygen species concentration. We therefore presumed that kaempferol-rutinoside is one of the main antioxidant phenolics in Crocus tepals. None of the tested extracts showed cytotoxicity toward Caco-2 cells. The results revealed that Cvv tepals have potential as a food supplement and are a promising material for further food safety tests.

Phenolic Composition of Leaf extracts of Ailanthus altissima (Simaroubaceae) with Antibacterial and Antifungal Activity Equivalent to Standard Antibiotics

Extracts of fresh and dry Ailanthus altissima leaves from Croatia were evaluated for their phenolic composition, antioxidant and antimicrobial activities. The methanolic extract had a higher concentration of total phenolics, flavonoids and non-flavonoids, as well as a higher antioxidant capacity than water extracts. Flavonoids identified in A. altissima leaves belong to two groups: flavones (glycosides of apigenin and luteolin) and flavonols (glycosides of quercetin and kaempferol). They were mainly present as glycosides, quercetin-3- O-glucoside was the predominant flavonoid. Only traces of aglycones were detected even after extract hydrolysis. Caffeic acid was the predominant phenolic acid both before and after hydrolysis, followed by chlorogenic acid after hydrolysis. The concentration of chlorogenic acid significantly increased soon after tissue fragmentation suggesting this compound is involved in rapid response against mechanical wounding in A. altissima. Therefore, to increase the chlorogenic acid concentration, mechanical wounding could be applied. The acetone leaf extract was as active against Escherichia coli as the positive control gentamicin. Both acetone and methanol:dichloromethane extracts had a higher activity against Candida albicans than a standard drug amphotericin B. Therefore, A. altissima could serve as a valuable resource for antimicrobial activity, which makes this species interesting for further investigation and possible pharmaceutical application.