Phenolic composition of Cynara cardunculus L. organs, and their biological activities

Polyphenols are bioactive molecules exhibiting a lot of scientific attention due to their multiple biological activities. This study compared phenolic contents and antioxidant activity in Cynara cardunculus L. organs and focus on leaf phenolic compounds identification by RP-HPLC and their antibacterial activity. The analyzed organs exhibited different total polyphenol contents (7-14.8 mg GAE g(-1) DW). Leaf and seed phenolic contents were similar and two times higher than those in flowers. The same tendency was observed for the amount of flavonoids and tannins. However, seed extracts displayed the highest DPPH. scavenging ability with the lowest IC50 value (23 microg ml(-1)), followed by leaves and flowers (over 50 microg ml(-1)). In contrast, leaves showed the highest capacity to quench superoxide (IC50: 1 microg ml(-1)) as compared to seeds (6 microg ml(-1)). In addition, cardoon leaves were efficient to inhibit growth of pathogenic bacteria mainly against Staphylococcus aureus and Escherichia coli. The identification of phenolic compounds from leaves revealed that syringic and trans-cinnamic acids were the major molecules.     

Evaluation of zinc tolerance and accumulation potential of the coastal shrub Limoniastrum monopetalum (L.) Boiss.

The coastal shrub Limoniastrum monopetalum is capable of growth in soil containing extremely high concentrations of heavy metals. A greenhouse experiment was conducted in order to investigate the effects of a range of Zn concentrations (0–130 mmol l⁻¹) on growth and photosynthetic performance, by measuring relative growth rate, total leaf area, plant height, gas exchange, chlorophyll fluorescence parameters and photosynthetic pigment concentrations. We also determined the total zinc, nitrogen, phosphorus, sulphur, calcium, magnesium, sodium, potassium, iron and copper concentrations in the plant tissues. The study species demonstrated hypertolerance to Zn stress, since survival was recorded with leaf concentrations of up to 1700 mg Zn kg⁻¹ dry mass when treated with 130 mmol Zn l⁻¹. L. monopetalum exhibited little overall effects on photosynthetic function at Zn levels of up to 90 mmol l⁻¹. At greater external Zn concentration, plant growth was negatively affected, due in all probability to the recorded decline in net photosynthetic rate, which may be linked to the adverse effect of the metal on photosynthetic electron transport. Growth parameters were virtually unaffected by leaf tissue concentrations as high as 1400 mg Zn kg⁻¹ dry mass thus indicating that this species could play an important role in the phytoremediation of Zn-polluted areas.     

Metal Phytoremediation by the Halophyte Limoniastrum monopetalum (L.) Boiss: Two Contrasting Ecotypes

The phytoremediation potential of the halophyte Limoniastrum monopetalum for the removal of Cd and Pb from polluted sites is assessed in this work. Two pot experiments were conducted; the first with wild L. monopetalum grown on soil polluted with Cd and Pb irrigated at different salinities, and the second with commonly cultivated ornamental L. monopetalum grown on soil polluted with Cd irrigated also at different salinities. The data revealed that wild L. monopetalum is a Cd and Pb tolerant plant able to accumulate at least 100 ppm of cadmium in its shoots without showing any significant decrease in terms of biomass production, chlorophyll content or water content suggesting that it could be an accumulator of Cd. Pb above-ground accumulation was kept at low levels with the majority of Pb localized in the roots. On the other hand, contrasting results were obtained for ornamental L. monopetalum which although it was found to be also Cd tolerant, Cd accumulation in its tissues was kept at significantly lower levels especially compared to that of the wild ecotype. In addition for ornamental L. monopetalum salinity did not have a positive effect on Cd accumulation and translocation as observed in the wild type and in other halophytes. Analysis of the salt excretion crystals on the leaf surface confirmed that wild and cultivated ornamental L. monopetalum excrete cadmium and lead through their salt glands as a possible metal detoxification mechanism, although the amount excreted by the ornamental L. monopetalum is significantly less.     

Variation in antioxidant activity and phenolic content in different organs of two Tunisian cultivars of Olea europaea L.

This paper reports a comparative study based on the antioxidant compounds, total phenol content and antioxidant activities of leaves, stems and fruits from the main Tunisian cultivars, ‘chetoui’ and ‘chemchali’, grown in two different locations, north and south of Tunisia. The repartition of olive phenolic compounds was organ dependant. Therefore, the HPLC analysis indicated that the olive organs from the northern cultivar had the highest level of hydroxybenzoic acids, hydroxycinnamic acids and flavonoid class; which were less in the southern cultivar. Principal component analysis of the phenolic compounds showed discrimination between methanol extracts of the organs olive. Significant differences (p < 0.05) in the levels of phenols, orthodiphenols and flavonoids were found between cultivars and between organs. Antioxidant activities of the methanolic extract from aerial parts of the two studied cultivars were evaluated using 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) assays. In all tests, methanolic extracts of different olive parts showed higher antioxidant activity. These results can be used to discriminate and to characterize the ‘chetoui’ and ‘chemchali’ aerial parts.     

Phenolic composition and biological activities of Tunisian Nigella sativa L. shoots and roots

In the present investigation, methanolic extracts from shoots and roots of Tunisian Nigella sativa were assayed for their antioxidant and antimutagenic activities. The phenolic composition of the methanolic extracts was determined by RP-HPLC. The predominant phenolic compound was vanillic acid with a mean concentration of 143.21 and 89.94 mg per 100 g dry weight of shoots and roots, respectively. Shoots and roots showed comparable and strong superoxide scavenger activity; however, shoots exhibited higher DPPH radical scavenging, reducing and chelating activities than roots. Mutagenic and antimutagenic activities were determined by using the Ames test. Shoots and roots demonstrated important antimutagenic effects. Roots exhibited stronger activity than shoots with an inhibition percentage of 71.32%.     

Variability of phenolic composition and biological activities of two Tunisian halophyte species from contrasted regions

The present study consists in evaluating the inter- and intraspecific variability of phenolic contents and biological capacities of Limoniastrum monopetalum L. and L. guyonianum Boiss. extracts. Ultimately, they were subjected to HPLC for phenolic identification. Results showed a great variation of phenolic content as function of species and localities. In fact, L. guyonianum extracts (El Akarit) contained the highest polyphenol (57 mg GAE g^?1 DW), flavonoid (9.47 mg CE g^?1 DW) and condensed tannin contents (106.58 mg CE g^?1 DW). These amounts were accompanied by the greatest total antioxidant activity (128.53 mg GAE g^?1 DW), antiradical capacity (IC₅₀ = 4.68 μg/ml) and reducing power (EC₅₀ = 120 μg/ml). In addition, L. monopetalum and L. guyonianum extracts exhibited an important and variable antibacterial activity with a diameter of inhibition zone ranging from 6.00 to 14.83 mm. Furthermore, these extracts displayed considerable antifungal activity. L. monopetalum extracts (Enfidha) showed the strongest activity against Candida glabrata and C. krusei with a diameter exceeding 12 mm. The phytochemical investigation of these extracts confirmed the variability of phenolic composition, since the major phenolic compound varied as a function of species and locality. These findings suggest that these two halophytes may be a new source of natural antioxidants that are increasingly important for human consumption, as well as for agro-food, cosmetic and pharmaceutical industries.     

Hypericum sp.: essential oil composition and biological activities

Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.     

Fractional changes in phenolic acids composition in root nodules of Arachis hypogaea L.

Phenolic acids are active antimicrobial compounds and root signaling molecules that play important roles in plant defense responses. They are generally present in plants as glycosides or esters. A range of soluble and bound phenolic acids were detected in roots and root nodules of Arachis hypogaea L., among which five were identified by high performance liquid chromatography (HPLC) coupled with UV–Vis diode array detector (DAD), viz., p-coumaric acid (p-com), p-hydroxybenzaldehyde (HBAld), p-hydroxybenzoic acid (HBA), caffeic acid (CA) and protocatechuic acid (PA). Para-coumaric acid was constitutively present in all fractions whereas HBA was present in the soluble form only in young nodules. CA and PA were mostly present in the wall bound fraction. The root nodules contain higher concentration of phenolic acids than non-nodulated roots and presence of peroxidase and polyphenol oxidase indicate the metabolism of phenolic acids in roots and root nodules. These results indicate that phenolic acids (p-com and CA) in bound-glycosidic or ester forms were major components in cell wall fortification which provide protection to the root nodule from pathogen attack.     

Two new lignans with their biological activities in Portulaca oleracea L.

Two new lignans, identified as 6,7-dihydroxy-4-(4′’-hydroxy-3′’-methoxyphenyl)-2-naphthoic acid, named Oleralignan C (1), and 4-(3,4-dihydroxyphenyl)-6-hydroxy-7-methoxy-2-naphthoic acid, named Oleralignan D (2), were obtained from Portulaca oleracea L. The structures were determined by spectroscopic methods, including UHPLC-ESI-QTOFMS, ¹D and ²D NMR. Both Oleralignan C (1) and Oleralignan D (2) inhibited the inflammatory factors, IL-1β and TNF-α in RAW 264.7 cells induced by lipopolysaccharide (LPS). Both compounds also could clear 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals indicating their antioxidant potential.     

Novel gelatinolytic activities in rat organs.

Novel gelatinolytic activities in both latent and active forms were detected in the normal organs of rat by gelatin zymography. Multiple active bands were detected in the extracts from the skin, jejunum, muscle, and kidney without any activation. These activities were inhibited by 1,10-phenanthroline or leupeptin, nor by E64, suggesting that these activities were derived from metallo-proteinases or serine-proteinases. Some gelatinolytic active bands were newly induced or enhanced by p-aminophenylmercuric acetate. These results suggest that matrix degrading activities due to metallo- and serine-proteinases were constitutively expressed in various rat normal organs.     

The cellular composition of the blood and haematopoietic organs of turbot Scophthalmus maximus L.

The cellular composition of the blood, anterior kidney, spleen and thymus of turbot Scophrhalmus maximus L., aged 1 + was determined. Ninety-four per cent of blood cells belonged to the erythrocyte lineage of which 82% were mature erythrocytes. The leucocytes, which represented 4.5% of the blood cells, were mainly lymphocytes (50%). The presence of crythroblasts in the anterior kidney and the spleen demonstrated an erythropoietic activity in both organs. However, this activity appeared to be prevalent in the spleen which also appeared to act as a storage zone for erythrocytes and as the centre point for thrombopoiesis. Although 96% of the anterior kidney cells were leucocytes, the number of white cells per gram of organ was higher in the spleen.     

Phytochemical composition and in vitro biological activities of Morinda citrifolia fruit juice

Morinda citrifolia is a plant with broad nutraceutical and therapeutic effects and used in the traditional treatment of several ailments. The objective of this work is to investigate the phytochemistry of the fruit juice of M. citrifolia on one hand and on other hand to evaluate its antiradical and antibacterial activity. The phytochemical investigation was carried out by tube staining tests of the extract of two types of fruit juice of M. citrifolia. The antioxidant activity of these juices was evaluated by reducing the DPPH radical method. Concerning the antibacterial activity, it was tested on the in vitro growth of 10 reference bacterial strains using the well diffusion method. Qualitative phytochemistry of M. citrifolia fruit juices revealed the presence of large groups of secondary metabolites including polyphenols, reducing compounds, mucilage and terpernoids. The antioxidant activity of M. citrifolia fruit juices is dose-dependent and higher than that of ascorbic acid. Antimicrobial activity on other hand revealed that fruit juices inhibit growth inhibitory activity of Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, S. epidermidis, Proteus vulgaris, Streptococcus oralis, Enterococcus faecalis and Escherichia coli. This observed difference is significant for each juices on the strains (p < 0.001). These results support the use of M. citrifolia in traditional medicine and are the starting points for the development of a new drug to combat both dietary conditions and chronic conditions associated with oxidative stress.     

Variation in some biological characteristics of British sea trout, Salmo trutta L.

Almost 50 assessments of British sea trout are available in the literature and the objective in this work is to examine variation in the parameters by which the fish are usually described and to discover biological criteria on which stocks may be classified. Eight statistics are common to the majority of stock evaluations: mean smolt age, proportion of finnock to spawn, mean age of a stock at first maturation, size achieved by the smolt at migration, rate of growth at sea, survival at sea, diversity of age categories in a stock and condition factor of sea-run fish. When the influence of each factor on the others is tested two characteristics emerge as being of key importance in the biology of adult sea-trout; the life expectancy and the weight: percentage previous spawners in a sample. The distribution of stocks is discussed in this context and two main groupings of British sea trout, corresponding geographically with the Irish sea and the Atlantic sea-board, are proposed.     

Seasonal variations of phenolic compounds and biological properties in sage (Salvia officinalis L.)

The aim was to investigate the phenolic content, antioxidant capacity, and antibacterial activity of Dalmatian sage (Salvia officinalis L.) leaves collected during different vegetation periods. Separation and quantification of the individual phenols were performed by reversed-phase (RP)-HPLC coupled with a PDA (photodiode array) detector and using an internal standard, while the contents of total phenols, flavonoids, flavones, and flavonols were determined spectrophotometrically. The antioxidant properties of the sage leaf extracts were evaluated using five different antioxidant assays (FRAP, DPPH, ABTS, Briggs-Rauscher reaction, and β-carotene bleaching). The antimicrobial activity of the extracts was tested against two Gram-positive (Bacillus cereus and Staphylococcus aureus) and two Gram-negative (Salmonella Infantis and Escherichia coli) bacterial reference strains. All extracts were extremely rich in phenolic compounds, and provided good antioxidant and antibacterial properties, but the phenophase in which the leaves were collected affected the phenolic composition of the sage extracts and consequently their biological activity. The May Extract, the richest in total flavonoids, showed the best antioxidant properties and the highest antimicrobial activity. Thus, collection of the plants during May seems the best choice for further use of them in the pharmaceutical and food industry.     

Phytochemical composition and biological activities of Asteriscus graveolens (Forssk) extracts

In the present study the phytochemical composition and biological activities of the aerial part extracts of Asteriscus graveolens against pathogenic bacteria and leishmania parasite were evaluated. Phytochemical analysis revealed the presence of polyphenols, flavonoids and tannins. The ethyl acetate fraction exhibited high antioxidant potential of 359.72 ± 32.03 μg and 326.76 ± 15.86 μg of ascorbic acid equivalents and 13.32 ± 0.19 μg/mL by PM, FRAP and DPPH assays respectively. This fraction also displayed a moderate antibacterial activity against Listeria monocytogenes ATCC 19115 (MIC = 0.312 mg/mL) and strong antileishmanial activity against both promastigote and amastigote forms with IC50 ranging from 22.93 ± 0.39 μg/mL to 35.23 ± 0.62 μg/mL. Furthermore the ethyl acetate fraction exhibited low cytotoxicity and good selectivity index towards the macrophage cell line Raw 264.7. HPLC analysis of the active fraction revealed the presence of hydroxycinnamic acid as major compound (30.56%). Asteriscus graveolens is a promising source of bioactive compounds that could be potentially used in cosmetic and pharmaceutical industry.     

Phytochemical composition and antioxidant activities of different aerial parts extracts of Ferula communis L.

The present study aimed to assess antioxidant activities of three organs (flower, fruit, and stem) extracts of Tunisian Ferula (F.) communis. Various experimental models were used to characterize the antioxidant activities in vitro as well as on ROS-induced fluorescence using dichlorofluorescein technique from phorbol myristate acetate (PMA)-stimulated human myeloid cell line HL-60. Results showed that the antioxidant activities varied considerably with organs. Thus, flower exhibited higher DPPH-scavenging ability, reducing and chelating power than stem and fruit. Also, antioxidant capacities using ORAC method and a cell-based assay showed that fruit and stem exhibited statistically similar antioxidant activities. Moreover, F. communis contains high amounts of flavonoids with various health benefits attributed to their antioxidant potential. Likewise, to obtain biologically relevant information, the antioxidant activities of the extracts were evaluated on cellular models implicating the antioxidant activities; this test generally showed that F. communis flower extracts have the highest antioxidant capacities correlated to the highest total phenolic content. The identification of phenolic compounds in F. communis extracts using RP-HPLC revealed that resorcinol, ferulic, and syringic acids together with coumarin were the major molecules.