Fraxinus Angustifolia Vahl Research Articles

Spectral Library of Plant Species from Montesinho Natural Park in Portugal

In this work, we present and describe a spectral library (SL) with 15 vascular plant species from Montesinho Natural Park (MNP), a protected area in Northeast Portugal. We selected species from the vascular plants that are characteristic of the habitats in the MNP, based on their prevalence, and also included one invasive species: Alnus glutinosa (L.) Gaertn, Castanea sativa Mill., Cistus ladanifer L., Crataegus monogyna Jacq., Frangula alnus Mill., Fraxinus angustifolia Vahl, Quercus pyrenaica Willd., Quercus rotundifolia Lam., Trifolium repens L., Arbutus unedo L., Dactylis glomerata L., Genista falcata Brot., Cytisus multiflorus (L’Hér.) Sweet, Erica arborea L., and Acacia dealbata Link. We collected spectra (300–2500 nm) from five records per leaf and leaf side, which resulted in 538 spectra compiled in the SL. Additionally, we computed five vegetation indices from spectral data and analysed them to highlight specific characteristics and differences among the sampled species. We detail the data repository information and its organisation for a better understanding of the data and to facilitate its use. The SL structure can add valuable information about the selected plant species in MNP, contributing to conservation purposes. This plant species SL is publicly available in Zenodo platform.

Green synthesis of silver nanoparticles from Fraxinus angustifolia Vahl. Extract: Characterization and assessment of their biological activities

Nanoparticle synthesis for biological devices is one of the most promising research fields invading the world. This work aimed to synthesize ecofriendly silver nanoparticles (AgNPs) with enhanced biological activities. A green method was adopted to synthesize, for the first time, AgNPs from Fraxinus angustifolia extracts. The AgNPs structural and morphological properties were characterized. Their antioxidant, antimicrobial and antidiabetic effects were investigated. Their cytotoxic and genotoxic effects were explored using the novel method of acetocarmine dye. Results confirmed the formation of stable, mono-dispersed and spheric nanoparticles with a Face-Centered Cubic crystalline structure, sized from 30.12 to 49.62 nm. The AgNPs showed high antioxidant activities (DPPH, β-carotene bleaching and total antioxidant activities). They significantly inhibited the growth of the multi-drug resistant pathogens Escherchia coli and Candida tropicalis. However, they showed moderate inhibitory activity against biofilm production of E. coli and C. tropicalis, with 65 and 63% inhibition, respectively. F. angustifolia AgNPs exhibited interesting antidiabetic activity, exceeding that of the acarbose. Interestingly, the acetocarmine stanning was approved as an exploration technique for the screening of cytotoxic and genotoxic effects. Allium cepa epidermis tissues treated by the AgNPs presented a visible morphological change in the cell membrane and the disruption of the nuclear envelope. The obtained results highlighted the versatile biological potential of F. angustifolia AgNPs allowing their use as green nanomaterials in food preservation, pharmaceutical formulation and in food quality prospecting. This work also affords a new method for screening possible cytotoxicity and genotoxicity of nanomaterials in agri-food applications.

Fungal Presence and Changes of Wood Structure in Bark Stripping Wounds Made by Red Deer (Cervus elaphus L.) on Stems of Fraxinus angustifolia (Vahl)

Narrow-leaved ash (Fraxinus angustifolia Vahl), a highly valued European forest tree species, has been severely affected by a large-scale decline, which is most probably driven by a complex of multiple interacting factors including fungi, which contribute to and accelerate this process. Red deer (Cervus elaphus L.) can be considered as one of the contributing factors, as they inflict damage on the stems of young trees by stripping the bark. These wounds not only represent suitable entry points for fungi which can cause tissue necroses and decomposition, they can lead to changes in the wood structure as well. The aims of this research were to analyze chosen parameters of bark stripping wounds in narrow-leaved ash stands, identify fungi present in the tissue exposed by wounding, and inspect the effect of wounding on the wood structure. Bark stripping was observed on ash trees from 2 cm up to 18 cm of DBH and between 0.1 m and 1.9 m of stem height. The most susceptible trees were those with an average DBH of 5 ± 2.5 cm. On most of the ash trees (51%), one-third to two-thirds of the circumference was damaged. In wounded tissue, 174 fungal isolates were found, most of which belonged to known endophytic fungi from the genera Trichoderma, Fusarium, and Clonostachys. It was observed that earlywood cells in the wounding zone had narrower lumens compared to ones in adjacent healthy zone with regard to different trees and stem heights.

Karacabey Kıyı Subasar Ormanlarında Kızılağaç ve Dişbudak yeşil yapraklarının biyokimyasal bileşimi üzerinde tuzlu su girişinin etkisi

Coastal forested wetlands provide substantial benefits to society, such as wave attenuation, erosion control, biodiversity support, and carbon sequestration. Many of these unique coastal ecosystems have been drained for various reasons, while those that remain are now threatened by salt water intrusion and sea level rise due to climate change. In this study, we aimed to investigate the effects of soil salinity on the biochemical components of the fresh leaves of alder (Alnus glutinosa L. Gaertn) and ash tree (Fraxinus angustifolia Vahl.) which are the dominant tree species in Karacabey coastal forested wetland next to the Sea of Marmara in Türkiye. For this purpose, fresh leaf and soil samples of alder and ash trees were collected from three zones (Z1: 0-1 km, Z2: 1 to 2 km and Z3: 2 to 3 km) from the inner border (Z3) of the forested wetland to the coastline (Z1) of the Sea of Marmara. The fresh leaf samples were analyzed for photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids), anthocyanin, xanthophylls, free amino acids, total nitrate, proline, total polyphenols, total soluble tannins, total phenolic compounds, glucose, sucrose and total carbohydrates. The soil samples were analyzed for soil pH, electrical conductivity and soil texture. The results showed that the soil salinity decreased from the coastline (Z1) towards the inner border (Z3). Similarly, mean photosynthetic pigments and anthocyanin, xanthophyll also decreased from the Z1 towards Z3, whereas mean total polyphenols and total soluble tannin concentrations increased for the both tree species. The other biochemical compounds showed either an increase or a decrease according to the tree species. These pioneer results illustrate the important point that biotic or abiotic environment in which tree grows significantly change the specific biochemical components in the fresh leaves of alder and ash trees in the coastal forested wetlands. In turn, these changes may result in variation in nutrient cycling, carbon cycling, and organic matter turnover rates in these forest ecosystems.

Plumilus grandicollis (Ménétriés, 1832) (Coleoptera: Anobiidae: Ptilininae): a new pest of ash wood (Fraxinus angustifolia Vahl, 1804) (Lamiales: Oleaceae) and locality report in Türkiye

This study was carried out in the Suleymaniye floodplain forests within the area of Hendek Forestry Enterprises in Sakarya province between the years of 2020-2021. Nine pheromone traps and 12 trap woods were placed in two different areas. In addition, the region's monthly temperature and relative humidity were recorded by a data logger that was placed in the study area. The pheromone traps and trap woods were checked every 20 days period and the insects were collected and identified in the laboratory. In addition, overturned ash woods were broken in the field and insects were collected and identified. In addition, boles and branches of the overthrown ash trees that were in the study area were cut into pieces in the field and developing insects were collected and identified. In this study, Plumilus grandicollis (Ménétriés, 1832) (Coleoptera: Anobiidae: Ptilininae) was detected with locality in Türkiye and as a new pest species for ash (Fraxinus angustifolia Vahl, 1804) (Lamiales: Oleaceae) wood

Forest Residue Management Impact on Rodent (Rodentia: Murinae, Arvicolinae) Damage in Pedunculate Oak (Quercus robur L.) Forests in Croatia

Small rodents (Rodentia, subfam. Murinae: real mice, Arvicoline voles) greatly affect natural regeneration, stability and dynamics of forest communities worldwide. Every 3–4 years rodent damage in Croatian state forests is the most severe in forest regeneration stands, especially in pedunculate oak (Quercus robur L.) and narrow-leaved ash (Fraxinus angustifolia Vahl.) forests, where rodents can seriously impede natural regeneration by damaging seeds, stems and roots of saplings. These negative interactions are an even bigger challenge nowdays as pedunculate oak and narrow-leaved ash have become more vunerable in the last decades and are known as the most sensitive species of lowland forests in Croatia due to microclimatic and macroclimatic changes and the unfavourable interaction of a whole series of anthropogenic, abiotic and biotic factors. In the last 40 years, in Croatian state forests, rodent management consisted of monitoring and mainly rodenticide use. Trying to implement IPM (Integrated Pest Management) postulates into practice over the years, different prevention methods against small rodents were tested, but not many came to use. The aim of this research was to look into different logging residue management approaches and their effect on the rodent damage in two pedunculate oak forest regeneration stands in central Posavina in Croatia. Rodent damage on stem and root of tree saplings was recorded by visual inspection on three plots (5x5 m) with scattered logging residue, and one plot (5x5 m) with no residue at one micro-depression site (95 m a.s.l.), and on one micro-elevation (99 m a.s.l.) site. Plots with scattered logging residue represented a type of forest residue management in which logging debris (branches) is cut to smaller lengths and distributed evenly at the forest regeneration stand. Plot with no logging debris represented a residue management method in which wood mass is completely removed from the regeneration stand after felling. We counted, determined and inspected tree saplings found at chosen plots for rodent damage (on stem and roots) and also determined the average weight and moisture content of logging residue (branches around 5–7 cm in diameter) found at the site. In spring 2017, 3380 tree saplings (2978; 81% pedunculate oak, 7; 0.2% narrow-leaved ash and 395; 11.7% other deciduous species) were inspected for rodent damage. At micro-depression site, on a plot with no logging residue, only 13.4% of the saplings were damaged, while the average share of damaged saplings on three plots with scattered residue was more than six times higher; 87.8%. The average mass of the logging residue weighed at site with scattered residue was 10.14 kg kg/m2 and moisture content was 19.2%. At micro-elevation site, 25.4% of the saplings were damaged on a plot with no logging residue, while the average share of damaged saplings on three plots with scattered residue was two times higher; 51.4%. The average mass of the logging residue weighed at SRP 1–3 was 5.1 kg/m2. We also determined moderately strong positive correlation (R=0.69133) between the mass of logging residue and rodent damage and strong negative correlation (R=–0.89598) between wood moisture content of the logging residue and rodent damage. In years ahead, with unpredictable climate effects and potentially very variable small rodent dynamics, removing the logging residue after the felling could represent a residue management that contributes to a more effective and ecologically based rodent management. It could also become a usable preventive method within IPM and help prevent sever rodent damage, even during the outbreaks in pedunculate oak regeneration stands.

First assessment of root biomass and root carbon and nitrogen stocks in Turkish floodplain forests.

Estimation of whole root biomass including coarse and larger roots and root balls can provide better understanding of carbon and nitrogen stocks in floodplain forests. Whole root systems of nine ash trees (Fraxinus angustifolia Vahl.) and six alder trees (Alnus glutinosa L.) trees ranging in diameter breast height (dbh) from 29.1 to 72.0cm for ash and from 29.1 to 44.3cm for alder were excavated, and their small < 1cm, medium 1-4cm, larger > 4cm and root-ball biomass, and root carbon and nitrogen stocks were determined in Karacabey floodplain forest in Bursa, Turkey. In addition, for the method comparison, small root biomass (< 1cm) was also determined using soil-core method. The whole root biomass of ash trees varied from 167.7 to 186.8Mgha-1. Alder trees had lower whole root biomass than ash trees ranging from 49.0 to 63.6Mgha-1. The determination of small root biomass by soil excavation method was nearly two-fold higher than by soil core method. Both root carbon and nitrogen stocks showed an increase with increasing root diameter. Among the tree characteristics (dbh, age, height, and volume), the dbh showed the highest correlation with whole root biomass and root carbon and nitrogen stocks for both tree species. It is concluded that young trees can have higher small, medium, and large root biomass and store more C and N in those roots, whereas older trees can have higher root-ball biomass and root-ball carbon and nitrogen stocks in Karacabey floodplain forests.

Effects of mixture and management on growth dynamics and responses to climate of Quercus robur L. in a restored opencast lignite mine

Opencast mining is currently one of the most destructive economic activities of natural ecosystems. Many restoration techniques have been developed to promote the recovery of terrestrial ecosystems degraded by mining, and afforestation and reforestation are among the most important methods to this purpose. In this study, we evaluated the combined effect of tree species mixture and thinning intervention on growth dynamics and responses to the climate of a target native planted oak (pedunculate oak, Quercus robur L.) about 40 years after reforestation of an opencast lignite mining area in Central Italy. The species used for reforestation were a native tree species (Q. robur L.), two valuable broadleaved trees (Fraxinus angustifolia Vahl. and Prunus avium L.) and a nitrogen-fixing tree (Alnus cordata Loisel.) to improve timber quality and restore the ecological and environmental value of the degraded land. Climate-growth relationships for precipitation, the Standardised Precipitation-Evaporation Index (SPEI), and temperature (on a monthly and seasonal scale) were tested together with indices based on tree-ring responses to drought. Thinning improved the stem quality and promoted a significant long-term increase in basal area increment (BAI, +31.0%) only in the mixture with alder. The thinning effect slightly mitigated radial growth reductions of oak trees during drought (resistance) and produced a general improvement in the magnitude of resilience and post-drought growth recovery (+37% and +27% on average, respectively). This effect was most evident when oak trees were mixed with only the N-fixing alder species, both after shorter- and longer-term drought or rainfall reduction. In conclusion, the mixture with alder combined with thinning practices resulted in the best management option to produce good-quality stems, improve growth performances, and mitigate drought effects in the recovery of opencast lignite mines through reforestation.

250-Year reconstruction of pollarding events reveals sharp management changes in Iberian ash woodlands

Key messageTree-ring growth of pollarded narrow-leaved ash trees in Central Spain reveals traditional management cessation in 1970 and property-specific management patterns.Tree pollarding was a dominant management strategy of European forests for centuries creating open agroforestry landscapes with important cultural and environmental values. This traditional practice has been widely abandoned in last decades with a subsequent impact in terms of biodiversity and cultural loss. Central Spain hosts the largest and best-preserved area of pollarded narrow-leaved ash (Fraxinus angustifolia Vahl.) woodlands in Europe. The main aim of this research is to obtain rigorous historical records of pollarding frequency to get adequate information for traditional ash management. We used dendrochronological techniques to evaluate temporal changes of pollarding frequency and rotation length. We analysed the stand level synchrony and the effect of land property on pollarding activity from 322 trees growing in eight pollard stands in Central Spain. Pollarding events were unequivocally identified at tree level by a characteristic change in growth pattern. We identified 2426 tree-level pruning events with the first event dated in 1777. Historical pruning recurrence ranged between 5 and 10 years with higher pollarding frequency on private lands. Pruning events within each site were synchronous, suggesting the existence of a rotational schema within each stand. Pruning frequency decreased drastically in the 1970s matching with the depopulation of rural areas and the general abandonment of traditional practices. Pollarding practices have recovered in recent decades although with lower intensity and lacking the synchronic historical patterns. Providing technical and economic support to make this traditional activity profitably would have strong environmental revenue due the multiple ecosystem services provided by pollarded ashes.

Analiza uticaja predtretmana vrelom vodom (LHW) na hemijski sastav drvnog iverja

The goal of this paper is to analyze the chemical composition of untreated and treated wooden chips from the native narrow-leaved ash (Fraxinus angustifolia Vahl. ssp. Pannonica Soó &amp; Simon). In order to determine the effect of pretreatment with liquid hot water (LHW) on changes in chemical composition, the content of moisture, cellulose, lignin, minerals (ash), extractives soluble in hot water, extractives soluble in organic solvents, for treated and for untreated wooden chips was determined. This was done in accordance with TAPPI and ASTM standard methods. The properties of wooden chips, treated for 30 min and 60 min at a temperature of 100 °C, are compared to untreated wooden chips and changes in the chemical composition that occurred are defined as a result of the applied treatments. The research was performed under controlled conditions in a laboratory, and the results of treatments were the subject of comparative analysis. Applied treatments had a statistically significant effect on decreasing the content of extractives. The content of cellulose and hemicellulose increased in the treated wooden chips compared to untreated wooden chips, while the lignin content did not significantly change.

First report of Fusarium tricinctum on narrow-leaved ash (Fraxinus angustifolia Vahl.) in Serbia

Monitoring the health status of narrow-leaved ash tree seedlings (forest office Morovic, locality Vinicna) in the early spring of 2015, after the catastrophic floods in May 2014, revealed presence of large dark necrotic areas on 1-2 year old sprouts. The isola?tion of the fungal pathogen was done by standard phytopathological protocols. Three repre?sentative isolates (K41, K42 and K78) were preliminary detected and purified by a single-spore technique for further morphological, molecular analyses and pathogenicity testing. Morphological characteristics classified the isolates as Fusarium tricinctum. Tested isolates on narrow leaved ash sprouts caused reddish brown elongated necrotic lesions averaged 20.1 mm. Two marker genes, translation elongation factor 1-alpha (TEF1-?) and internal transcribed spacer (ITS1), were used in this study. Using the Basic Local Alignment Search Tool (BLAST) searching engine, nucleotide sequences were compared to all related sequences. Alignement score resulted in 98.9% identities with F. tricinctum for isolate K78, while isolates K41 and K42 showed 94.1% and 94.3% identities with F. tricinctum complex respectively. To the best of our knowledge, this is the first report of F. tricinctum pathogen infection on flood stressed narrow-leaved ash trees in Serbia.

Chemical, hygroscopic, and mechanical properties of various wood species heat treated via the ThermoWood® method

Fourier-transform infrared spectroscopy (FTIR), energy dissipation spectrometry, dimensional stability, and compressive strength tests were conducted parallel to the fibers on various heat-treated trees, i.e., narrow-leaved ash (Fraxinus angustifolia Vahl), aspen (Populus tremula L.), Oriental spruce (Picea orientalis (L.) Link.), and Uludağ fir (Abies bornmüelleriana Mattf.), which grow naturally in forests in Turkey. Panels made from these trees were first heat treated via the ThermoWood® method, producing ThermoWood® panels. Then, FTIR, as well as energy dissipation spectrometry analysis, dimensional stability, and compressive strength tests were performed on test samples prepared from the panels. The FTIR data showed that the hemicelluloses were degraded in the ThermoWood® test samples and the proportion of cellulose increased. The energy dissipation spectrometry results showed that the amount of carbon increased, the amount of oxygen decreased, while the amount of hydrogen remained approximately the same in the ThermoWood® panels compared to the control samples. It was determined that the proportion of silicon increased in the narrow-leaved ash panels. In addition, among the physical properties, the amount of shrinkage and swelling decreased in all the tested ThermoWood® panels compared to the control samples, whereas the compressive strength values, which are considered a mechanical property, increased.

Species-Specific Effects of Groundwater Level Alteration on Climate Sensitivity of Floodplain Trees

European floodplain forest is facing increasingly frequent and severe drought events related with ongoing climate change. Moreover, this ecosystem type was frequently affected by river regulation, leading to groundwater table lowering; however, river revitalization has, in some locations, achieved some restoration of groundwater levels. In this study, we investigated the growth–climate sensitivity and growth modulation after groundwater-level manipulation for Fraxinus angustifolia Vahl. and Quercus robur L. in one of the most important floodplain forest complexes in Central Europe. We constructed three different types of tree ring chronologies to reflect the high frequency variability, medium-low frequency variability, and basal area increment. We found F. angustifolia to be more sensitive than Q. robur to both drought and groundwater level fluctuations. Moreover, F. angustifolia showed more pronounced short-term and long-term growth decreases after artificial ground water level alteration than did Q. robur. We also found that the groundwater level increase due to river revitalization reduced the climate sensitivity for both F. angustifolia and Q. robur. The decrease in climate sensitivity associated with revitalization was more pronounced for F. angustifolia which, moreover, showed a greater basal growth after river revitalization. Our results suggest that F. angustifolia will be more threatened than Q. robur by the diminution in groundwater availability and increase in drought with ongoing climate change. They also show that river revitalization can be a suitable management tool to help the adaptation to climate change.

Characterization of phenolic compounds isolated from the Fraxinus angustifolia plant and several associated bioactivities

In Algeria, Fraxinus angustifolia Vahl (Oleaceae) is a prominent ingredient for the treatment of inflammatory diseases caused by oxidative stress. This study aimed to make a comparison between the phenolic compound compositions of the ethanolic and aqueous extracts (decoction and infusion) of this plant and to test the antioxidant, cytotoxic and anti-pancreatic lipase activities of the ethanolic extracts from the leaf and bark. The identification and quantification of phenolic compounds was carried out by HPLC-DAD-MS and the antioxidant activity was assessed according to three methods: Ferric Reducing Antioxidant Power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical scavenging activity and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity. The cytotoxic effect was investigated using the human colon adenocarcinoma cell line HCT-116; while pancreatic lipase inhibitory activity was examined using 4-nitrophenyl butyrate (NPB) as a substrate. A large variety of phenolic compounds were detected and the content of the leaf was much higher than that of the bark. The ethanolic extracts from the leaf had a higher antioxidant capacity than those of the bark, however, the latter showed greater antilipase activity and cytotoxicity than the former. These results suggest that this plant may be an important source of active compounds with a variety of biological activities which justify its use in traditional medicine.

Preliminary results on narrow-leaved ash (Fraxinus angustifolia Vahl) and green ash (Fraxinus pennsylvanica Marshall) seed entomofauna in Croatia

Native narrow-leaved ash (Fraxinus angustifolia Vahl) and introduced green ash (F. pennsylvanica Marshall) are two most common ash (Fraxinus spp.) species in Croatian lowland forests, taking a significant place in these ecosystems. In the recent past it has been observed that narrow-leaved ash seed yields have reduced, emphasising the importance of good health status of those collected, as they are used for seedling production and consecutive regeneration of forest stands or afforestation. Given that insects could be an important factor affecting ash seed health status, the aim of this research was to gain insight into the species being present and their frequency in the ash seeds. In total 2.500 narrow-leaved ash and 1.000 green ash seeds from seven different locations were screened for insect presence. Analysed seeds were categorized as undamaged, insect damaged or empty, and observed insect specimens were identified by morphological and molecular genetic analysis. Green ash seeds revealed higher insect infestation in comparison with native ash species, with weevil Lygniodes bischoffii being the most numerous pest found. Narrow-leaved ash seeds were mostly occupied by the native weevil species, L. enucleator. Besides these pests, larval, pupal, and adult stages of parasitoid wasps (Hymenoptera) and larval stage of the seed eating moth Pseudargyrotoza conwagana (Lepidoptera) were found in both ash species. However, given that pests detected in this study prefer urban areas or were present in a very small number of seeds, where they were often followed by parasitoids, it can be concluded that insects currently do not have a significant negative impact on the reproduction of narrow-leaved ash and green ash in forest stands.

Dendrohydrological Reconstructions Based on Tree-Ring Width (TRW) Chronologies of Narrow-Leaved Ash in the Sava River Basin (Croatia)

Current flood risk management is based on statistical models and assessments of the risk of occurrence over a given time period, although with very short measurement periods, usually following catastrophic events. Ongoing monitoring of basic hydrological (river-water level and streamflow) and climate data are the basis for sustainable water management and long-term flood control planning. The lack of data has proven to be particularly negative during this period of global climate change, when non-seasonal flooding (during summer) is becoming increasingly frequent, and the resulting damage greater. The aim of this study was to analyse the possible use of tree ring width chronologies of trees growing in floodplain areas to reconstruct hydrodynamic variables (river-water level and streamflow). The study analysed the influence of climatic and hydrological variables on the growth of narrow-leaved ash (Fraxinus angustifolia Vahl) in the Sava River basin. The results indicate the significant potential of narrow-leaved ash tree-ring width chronologies to reconstruct the summer streamflows of the Sava River (R2 = 0.45). These results can serve to develop long-term data series on the summer streamflows of the river, thereby enabling better insight into its spatial and temporal dynamics with the goal of more successful, sustainable management of floodplain areas.

Anti-Proliferative Activity of A Hydrophilic Extract of Manna from Fraxinus angustifolia Vahl through Mitochondrial Pathway-Mediated Apoptosis and Cell Cycle Arrest in Human Colon Cancer Cells.

Manna is produced from the spontaneous solidification of the sap of some Fraxinus species, and, owing its content in mannitol, is used in medicine as a mild laxative. Manna is also a rich source of characteristic bio-phenols with reducing, antioxidant and anti-inflammatory properties. This study assesses the activity of a hydrophilic extract of manna (HME) on cellular and molecular events in human colon-rectal cancer cells. HME showed a time- and concentration-dependent anti-proliferative activity, measured by MTT assay, in all the cell lines examined, namely Caco-2, HCT-116 and HT-29. The amounts of HME that caused 50% of cell death after a 24 h treatment were 8.51 ± 0.77, 10.73 ± 1.22 and 28.92 ± 1.99 mg manna equivalents/mL, respectively; no toxicity was observed in normally differentiated Caco-2 intestinal cells. Hydroxytyrosol, a component of HME known for its cytotoxic effects on colon cancer cells, was ineffective, at least at the concentration occurring in the extract. Through flow-cytometric techniques and Western blot analysis, we show that HME treatment causes apoptosis, assessed by phosphatidylserine exposure, as well as a loss of mitochondrial membrane potential, an intracellular formation of reactive oxygen species (ROS), increases in the levels of cleaved PARP-1, caspase 3 and Bax, and a decrease in Bcl-2 expression. Moreover, HME interferes with cell cycle progression, with a block at the G1/S transition. In conclusion, the phytocomplex extracted from manna exerts an anti-proliferative activity on human colon cancer cells through the activation of mitochondrial pathway-mediated apoptosis and cell cycle arrest. Our data may suggest that manna could have the potential to exert chemo-preventive effects for the intestine.

The decline of Fraxinus angustifolia Vahl in a Mediterranean salt meadow: Chlorophyll fluorescence measurements in long-term field experiment

The ecological transition zones also known as ecotones are specific ecosystems but how global change will affect their biodiversity and functioning is poorly understood. In the case of the areas at the interface between riparian forest and salt meadows the biodiversity conservation remains a major issue. The aim of this work was to evaluate the effects of a salty environment on Fraxinus angustifolia a non-halophyte species. For this, the photochemistry of PSII was in situ explored during the summer between 2007 and 2016. The predawn maximum quantum efficiency of PSII (Fv/Fm) was always greater than 0.8 which indicates an absence of chronic photoinhibition induced by salinity. During these years, the light kinetic of the actual quantum yield of PSII (ΦPSII) was studied. It appears that this yield is generally higher in salty environments than in the riparian forest. Multivariate analysis, showed that the dissipation regulated light energy faction (ΦNPQ), the photochemical quenching (qP) and the Fd/Fs ratio constitute the main explanatory variables of ΦPSII changes. The subsequent two-way-ANCOVA carried out demonstrated that ΦNPQ was weaker in saline environments, suggesting a better efficiency of photosystem collecting antennas. Meanwhile, the analysis of photosynthetic pigments did not exhibited a salt effect except the significant accumulation of chlorophyll a in 2016. In order to address the question of the salt-related toxicity, sodium ion contents in the leaves were found to be identical in the two sites, suggesting the establishment of an energy-dependent mechanism of salt exclusion/retention in roots. The growth rings of F. angustifolia in saline areas highly follows the annual water deficit changes. Between 2007 and 2016, the biomass in the salt meadow was higher with a peak in 2011 representing 60% of the biomass of control individuals. But, since 2011 a continuous decline of growth was recorded. Water conditions seem to constitute a limiting factor even if the photosynthetic apparatus generates the excess metabolic energy necessary to cope with the saline toxicity. This study thus highlighted the plasticity of the photochemistry of the PSII depending to the environmental conditions of the salt meadows. It also shows the vulnerability of an ecotone through the decline in the productivity of a glycophyte with climate change. This augurs for changes in the composition of plant communities which is in favor of strict halophytes.

Phytochemical Study and Antibacterial Effects of Fraxinus angustifolia Vahl (Algeria): Experimental and Computational Investigations

We investigated experimentally the composition of volatile isolates from the leaves and seeds of fraxinus angustifolia Vahl and their antimicrobial activity. The experimental work was supported by a theoretical study, using the Functional Density Theory. The calculations were performed at the B3LYP/6–31 g-d, p), in order to determine the structures of major volatile compounds and the different descriptors of reactivity and biological activity. The chemical composition of the volatile isolates obtained by hydrodistillation of the leaves and seeds are evaluated by the analytical method of gas chromatography-mass spectrometry (GC-MS). We found that the leaves are composed of abundant compounds, specifically, docosane methyl (30.2%), n-Pentacosane (28.5), α-cadinol (9.0%) and T-muurolol (5.9%). Moreover, the isolate from the seeds, is found to be mainly composed of α-cadinol (23.2%) and epi-methyljasmonate (34. 2%). Additionally, we perform antimicrobial activity tests on the volatile isolated using the zone of inhibition (agar disk-diffusion method) of four bacteria strains, mainly, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli. The values of leaves range from 100 to 300 µg of volatile compounds, whereas for the seeds the values lie between 20 and 300 µg. Furthermore, antifungal susceptibility tests are conducted on two yeast strains: Saccharomyces cerevisiae and Candida albicans. The seeds have a better inhibition than the leaves, with 20 and 300 µg respectively. The chemical compositions of the volatile fractions of leaves and seeds are correlated with the antimicrobial results. The reactivity descriptors are calculated to determine stability and microbiological activity of the above compounds. The Isopimaradiene presents the higher microbiological activity and the most stable T-muurololis.

Genetic Distinctiveness Highlights the Conservation Value of a Sicilian Manna Ash Germplasm Collection Assigned to Fraxinus angustifolia (Oleaceae).

The cosmopolitan genus Fraxinus comprises about 40 species occupying several habitats in the Northern Hemisphere. With some species hybridizing and sharing genetic variants, questions remain on the species assignment of germplasm within the genus Fraxinus despite numerous species-specific assessments. A multidisciplinary approach was employed to provide a definitive insight into the genetics of an endangered Fraxinus “manna ash” collection, located in a rich plant biodiversity hotspot of the Madonie Mountains (Sicily). Although the collection size was small, genetic diversity, assessed by chloroplast (cpSSR) and nuclear (nSSR) microsatellites (SSR—Simple Sequence Repeats), allowed identifying three different chloroplast haplotypes, with one (H5) dominant, and several polymorphic loci, able to discriminate most of the local accessions studied. Molecular data were linked to cytofluorimetric and phenotypic evaluations and, contrary to popular belief that manna ash is Fraxinus ornus L., the germplasm currently used for manna production belongs to Fraxinus angustifolia Vahl. Interestingly, joint analysis of our genetic panel with a large European dataset of Fraxinus spp. suggested the presence of a possible glacial refuge in Sicily, confirming its importance as biodiversity source. Our results will be helpful for the design of long-term conservation programs for genetic resources, such as in situ and ex situ conservation, seed collection and tree reintroduction.