New esters from the essential oil of dry flowers of elder (Sambucus nigra L.).

BACKGROUND: Elder (Sambucus nigra L.) has relevance for the food, fragrance and pharmaceutical industries. Flowers of this species emit a very pleasant scent; for processing purposes, inflorescences are either collected from the wild or harvested from a cultivated crop. The study of elderflower-derived volatiles bears both phytochemical and commercial importance. RESULTS: Three samples of dry elderflower essential oil obtained from laboratory-scale hydrodistillations were analyzed. By use of gas chromatography-mass spectrometry, synthesis and NMR studies of chromatographic fractions of a distillation water extract prepared in a semi-industrial scale steam distillation, 252 constituents of the oil were identified; 115 compounds were not previously reported as elderflower volatiles, seven of which were new natural esters. Particularly interesting were those of isosenecioic (3-methylbut-3-enoic) acid because these were never before found in the plant kingdom. CONCLUSION: With these identifications, the known essential oil constituents accounted for 89.0-93.0% of the analyzed samples. Although the number of known S. nigra flower-derived volatiles is now quite high, further research (both analytical and olfactory) is needed to unveil all of the relevant contributions to the unique odor of elderflowers. © 2023 Society of Chemical Industry.

Plant lectins as versatile tools to fight coronavirus outbreaks.

The S protein forming the homotrimeric spikes of pathogenic beta-coronaviruses, such as MERS-CoV, SARS-CoV and SARS-CoV-2, is a highly glycosylated protein containing mainly N-glycans of the complex and high-mannose type, as well as O-glycans. Similarly, the host cell receptors DPP4 for MERS-CoV and ACE2 for SARS-CoV and SARS-CoV-2, also represent N- and O-glycosylated proteins. All these glycoproteins share common glycosylation patterns, suggesting that plant lectins with different carbohydrate-binding specificities could be used as carbohydrate-binding agents for the spikes and their receptors, to combat COVID19 pandemics. The binding of plant lectins to the spikes and their receptors could mask the non-glycosylated receptor binding domain of the virus and the corresponding region of the receptor, thus preventing a proper interaction of the spike proteins with their receptors. In this review, we analyze (1) the ability of plant lectins to interact with the N- and O-glycans present on the spike proteins and their receptors, (2) the in vitro and in vivo anti-COVID19 activity already reported for plant lectins and, (3) the possible ways for delivery of lectins to block the spikes and/or their receptors.

Novel insights on extraction and encapsulation techniques of elderberry bioactive compounds.

BACKGROUND: Elderberry (Sambucus nigra L.) has been used in traditional medicine and as a supplement in many beverages and meals. Elderberry is a good source of bioactive flavonoids like quercetin, kaempferol, and rutin, as well as other phenolic compounds. Extraction techniques significantly influence the efficiency of extraction of bioactive compounds. Green chemistry elements such as safety, environmental friendliness, run-down or at least minimal contaminants, efficiency, and economic criteria should all be addressed by an effective bioactive extraction process. Furthermore, micro/nanoencapsulation technologies are particularly effective for increasing bioavailability and bioactive component stability. SCOPE AND APPROACH: This review article comprehensively describes new developments in elderberry extraction and encapsulation. Elderberry is largely employed in the food and pharmaceutical industries due to its health-promoting and sensory characteristics. Elderberry has traditionally been used as a diaphoretic, antipyretic, diuretic, antidepressant, and antitumor agent in folk medicine. KEY FINDINGS AND CONCLUSIONS: Conventional extraction methods (e.g. maceration and Soxhelt extraction) as well as advanced green techniques (e.g. supercritical fluids, pulsed electric field, emulsion liquid extraction, microwave, and ultrasonic extraction) have been used to extract bioactives from elderberry. Over the other protective measures, encapsulation techniques are particularly recommended to protect the bioactive components found in elderberry. Microencapsulation (spray drying, freeze drying, extrusion, emulsion systems) and nanoencapsulation (nanoemulsions, solid lipid nanoparticles and nanodispersions, nanohydrogels, electrospinning, nano spray drying) approaches for elderberry bioactives have been examined in this regard.

Flavonoid-Rich Sambucus nigra Berry Extract Enhances Nrf2/HO-1 Signaling Pathway Activation and Exerts Antiulcerative Effects In Vivo.

Sambucus nigra (SN) berry extract is characterized by high antioxidant and anti-inflammatory activity. The current study aimed to investigate the effect of SN berry extract against indomethacin (IND)-induced gastric ulcer in rats and the mechanism involved. SN berry extract alleviated IND-induced gastric ulcers, as shown by assessing pathological manifestations in the gastric mucosa. These protective effects are attributed to attenuated oxidative damage to the gastric mucosa, correlated to increased activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), enhanced glutathione (GSH) levels, total antioxidant capacity (TAC), and upregulation of the Nrf2/HO-1 cascade. Moreover, oxidative stress markers, including malondialdehyde (MDA) and total oxidant status (TOS), were downregulated in SN-extract-treated animals. Furthermore, SN berry extract suppressed gastric mucosal inflammation by downregulating interleukin (IL)-33, IL-1ß, IL-6, and tumor necrosis factor-alpha (TNF-α) levels, and attenuating myeloperoxidase (MPO) activity. The protective effects of SN berry extract were similar to those exerted by esomeprazole (ESO), an acid-secretion-suppressive drug. In conclusion, SN berry extract has antiulcerative effects, alleviating oxidative stress and inflammation.

Health-Promoting Properties: Anti-Inflammatory and Anticancer Properties of Sambucus nigra L. Flowers and Fruits.

Sambucus nigra L. has been used for centuries in traditional medicine thanks to its valuable healing properties. The healing properties result from its high content of biologically active compounds, mainly antioxidants, which contribute to its anti-inflammatory and anticancer properties. In our review, we have presented scientific studies evaluating the anti-inflammatory and anticancer effects of extracts and their components from S. nigra L. flowers and fruits. The results of the research show that the effect of antioxidant phytochemicals contained in their composition reduces the level of free radicals and pro-inflammatory cytokines, prevents mutations that increase the risk of cancer development, and inhibits cell proliferation, induction of apoptosis, and changes in intracellular signaling, consequently inhibiting the growth of malignant tumors and the formation of metastases. Flowers and fruits of S. nigra L. are a valuable source of nutraceutical and pharmacological substances that can support prevention and anti-inflammatory and oncological therapy without negative side effects for the patient.

Elderberry Extracts: Characterization of the Polyphenolic Chemical Composition, Quality Consistency, Safety, Adulteration, and Attenuation of Oxidative Stress- and Inflammation-Induced Health Disorders.

Elderberry is highly reputed for its health-improving effects. Multiple pieces of evidence indicate that the consumption of berries is linked to enhancing human health and preventing or delaying the onset of chronic medical conditions. Compared with other fruit, elderberry is a very rich source of anthocyanins (approximately 80% of the polyphenol content). These polyphenols are the principals that essentially contribute to the high antioxidant and anti-inflammatory capacities and the health benefits of elderberry fruit extract. These health effects include attenuation of cardiovascular, neurodegenerative, and inflammatory disorders, as well as anti-diabetic, anticancer, antiviral, and immuno-stimulatory effects. Sales of elderberry supplements skyrocketed to $320 million over the year 2020, according to an American Botanical Council (ABC) report, which is attributable to the purported immune-enhancing effects of elderberry. In the current review, the chemical composition of the polyphenolic content of the European elderberry (Sambucus nigra) and the American elderberry (Sambucus canadensis), as well as the analytical techniques employed to analyze, characterize, and ascertain the chemical consistency will be addressed. Further, the factors that influence the consistency of the polyphenolic chemical composition, and hence, the consistency of the health benefits of elderberry extracts will be presented. Additionally, adulteration and safety as factors contributing to consistency will be covered. The role of elderberry in enhancing human health alone with the pharmacological basis, the cellular pathways, and the molecular mechanisms underlying the observed health benefits of elderberry fruit extracts will be also reviewed.

The Effect of Sample Pretreatment on the Anthocyanin Content in Czech Wild Elderberry (Sambucus nigra L.).

This work focusses on the analysis of anthocyanins present in wild Czech elderberries, using spectrophotometric methods and liquid chromatography. Spectrophotometric methods were used to determine antioxidant capacity, total phenolic content, and total anthocyanin content. Further, four major elderberry anthocyanins were determined using reversed-phase high-performance liquid chromatography with isocratic elution of 30% aqueous methanol with 5% of formic acid. All optimised methods were applied to the analysis of extracts prepared from frozen and dried elderberry fruit samples, and the results were evaluated using principal component analysis which clearly divided the samples into individual groups according to the sample pretreatment (frozen and dried samples). The frozen samples reached higher values of antioxidant capacity and total phenolic and anthocyanin contents compared to the dried samples, probably due to the degradation of anthocyanins during the drying process.

Effect of cultivar, maturation stage, and year on sugar and phenolic composition of elderberries.

BACKGROUND: The chemical composition, phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) activity of the three main Portuguese elderberry cultivars were determined for the first time through five stages of maturation, in different harvesting years, to gain a deeper understanding of the effect of climatic conditions and enzymatic activity involved in the synthesis and degradation of phenolic compounds on the final quality of elderberries. RESULTS: Simple sugar and anthocyanin content increased with maturation but total acidity and flavonoids content decreased, and cinnamic acids did not show a clear trend. Climatic conditions seem to have a decisive influence on the elderberry maturation, namely the total number of hot (>30 °C) days. The PAL, PPO, and POD activity can explain the differences observed in elderberry phenolic content. CONCLUSION: These results highlighted the influence of climatic conditions in each harvesting season on elderberry development and quality. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Primary care experience on Stimunex® gocce in children with recurrent respiratory infections: a real-world study during the COVID-19 pandemic era.

BACKGROUND: Respiratory infections (RI) significantly burden society, mainly when there are recurrent respiratory infections (RRI). Thus, there is a need to prevent RI in clinical practice. In this regard, the modulation of the immune system and resolution of the inflammatory cascade could represent an ideal way to prevent RI. Stimunex® gocce, a multicomponent food supplement, contains Sambucus nigra extract, ß-glucan, Zinc, and Vitamin D3. This study investigated its ability to prevent RRI in children using a real-world setting: the pediatric primary care. MATERIALS AND METHODS: Two hundred and ninety-eight children with RRI were enrolled in the current study. The food supplement was randomly prescribed to 160 children with RRI daily for 4 months (Active group); the remaining 138 children with RRI were treated only with standard therapy for RI (Control group). The number and duration of RI, parental perception of symptom severity and treatment efficacy, use of medications, and school and working absence were evaluated. RESULTS: Children treated with Stimunex® gocce had significantly less RI than the Control group, both concerning upper and lower RI (p˂0.001 and 0.003, respectively) during the follow-up period. Moreover, children in the Active group experienced shorter RI duration during the treatment and follow-up phases (p˂0.001 for both). In addition, parents of treated children perceived less severe symptoms and better treatment efficacy during the first and follow-up phases (p˂0.001 for all). The food supplement was well tolerated and there was no adverse event. CONCLUSIONS: The current real-world study demonstrated that Stimunex® gocce supplementation in children with RRI might safely prevent RI episodes and reduce RI duration. These outcomes should be highlighted as obtained during the COVID-19 pandemic era, characterized by a dramatic reduction of RI.

Antiviral activity of plant juices and green tea against SARS-CoV-2 and influenza virus.

Respiratory viruses pose a significant threat to global health. They initially infect the naso- and oropharyngeal regions, where they amplify, cause symptoms, and may also be transmitted to new hosts. Preventing initial infection or reducing viral loads upon infection might soothe symptoms, prevent dissemination into the lower airways, or transmission to the next individual. Several natural products have well-described direct antiviral activity or may ameliorate symptoms of respiratory infections. We thus analyzed the potential of plant-derived products to inactivate respiratory viral pathogens and determined the antiviral activity of black chokeberry (Aronia melanocarpae [Michx.] Elliott), elderberry (Sambucus nigra L.), and pomegranate (Punica granatum L.) juice, as well as green tea (Camellia sinensis [L.] Kuntze) on the infectivity of the surrogate-modified vaccinia virus Ankara, and the respiratory viruses severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), and adenovirus Type 5. Black chokeberry and pomegranate juice, and green tea reduced SARS-CoV-2 and IAV titers by ≥80% or ≥99%. This suggests that oral rinsing with these products may reduce viral loads in the oral cavity which might prevent viral transmission.

Comparison of the Chemical Composition of Selected Varieties of Elderberry with Wild Growing Elderberry.

Elderberries of wild-growing shrubs are most often used; however, various cultivated varieties of this shrub appear more and more often. The aim of this research was to compare the fruit composition of specific varieties with those grown wild in urban and ecologically clean conditions. Six varieties of elderberry grown on one experimental farm and two wild-growing samples from the city center and the landscape park were assessed. The content of vitamin C, antioxidant activity, sugar and organic acid content, triterpenes and carotenoids was marked in the tested fruits. The analyses show that there were significant differences in the content of the tested ingredients between the varieties tested, while the place of cultivation was of less importance. Apart from organic acids and triterpenes, fruits from wild-growing shrubs were more abundant in other compounds determined. The white variety of 'Albida' turned out to be the poorest in bioactive compounds.

Water-in-Oil-in-Water Double Emulsions as Protective Carriers for Sambucus nigra L. Coloring Systems.

The use of natural colorants is needed to overcome consumer concerns regarding synthetic food colorants' safety. However, natural pigments have, in general, poor stability against environmental stresses such as temperature, ionic strength, moisture, light, and pH, among others. In this work, water-in-oil-in-water (W1/O/W2) emulsions were used as protective carriers to improve color stability of a hydrophilic Sambucus nigra L. extract against pH changes. The chemical system comprised water and corn oil as the aqueous and oil phases, respectively, and polyglycerol polyricinoleate (PGPR), Tween 80, and gum Arabic as stabilizers. The primary emulsion was prepared using a W1/O ratio of 40/60 (v/v). For the secondary emulsion, W1/O/W2, different (W1/O)/W2 ratios were tested with the 50/50 (v/v) formulation presenting the best stability, being selected as the coloring system to test in food matrices of different pH: natural yogurt (pH 4.65), rice drink (pH 6.01), cow milk (pH 6.47), and soy drink (pH 7.92). Compared to the direct use of the extract, the double emulsion solution gave rise to higher color stability with pH change and storage time, as corroborated by visual and statistical analysis.

Incorporation of the Dry Blossom Flour of Sambucus nigra L. in the Production of Sponge Cakes.

The present study aims to develop recipe compositions and technology for producing sponge cakes from wholemeal flour, partially replaced with a functional plant component dry blossom flour of Sambucus nigra L. Three designs of sponge cakes with 5, 10, and 15% content of flour of Sambucus nigra L. corrected up to 100% with whole-grain oat flour were studied. Their characteristics were compared with sponge cakes of 100% wheat flour/control. The obtained new products were characterized by reduced carbohydrates, increased content of dietary fiber, and preserved volume compared to the control. The physicochemical parameters of sponge cake and marshmallows with different concentrations of dry flowers of Sambucus nigra L. included in them differed from the control with lower water absorption, pH, and moisture, while having a higher relative mass and ash content and retaining the original size. Pathogenic microorganisms such as Escherichia coli, Salmonella sp., and Staphylococcus aureus, and common coliforms were not detected in the control and experimental samples when determining the microbiological parameters. Therefore, the developed formulations are an excellent alternative to wheat flour, significantly improving some nutritional characteristics such as smell, taste, dietary fiber, and lower carbohydrate content.

Wild Sambucus nigra L. from north-east edge of the species range: A valuable germplasm with inhibitory capacity against SARS-CoV2 S-protein RBD and hACE2 binding in vitro.

Berries and flowers of Sambucus nigra L. tree are well known for their ability to mitigate symptoms of upper respiratory disorders related to reported antiviral properties. Industrial application and commercial cultivation of S. nigra is largely limited to a few widely grown cultivars. Restricted genetic diversity of cultivated S. nigra can be disadvantageous if new industrial applications are discovered. In this study wild S. nigra populations located on the north-east edge of the species natural range were explored by assessing genetic origin, berry and flower anti-oxidative potential, and berry rutin content. Best performing wild S. nigra extracts were selected for an assessment of previously unreported biological activity- inhibitory capacity against SARS-CoV2 S1 protein receptor binding domain (RBD) binding to recombinant human angiotensin -converting enzyme 2 (ACE2) receptor in vitro based on competitive enzyme linked immunosorbent assay (ELISA). Inter-simple sequence repeat (ISSR) marker-based genetic characterization suggested that explored wild S. nigra populations result from wild gene pool expanding northwards with admixture of historically introduced cultivated S. nigra. Average values of total phenolic content, anti-radical activity, and total flavonoids content of wild S. nigra populations did not exceed those of cv. 'Haschberg'. Concentration-dependent inhibition of ACE2-SARS-CoV2 S-protein RBD binding was demonstrated in vitro for elderberry fruits and flowers extracts (IC50 of 1.66 mg DW ml-1 and 0.532 mg DW ml-1, respectively). Wild elderberry fruit extract exhibited higher inhibitory capacity than the extract from berries of cv 'Haschberg'. This study validates the requirement for S. nigra wild germplasm bioprospecting and opens up directions for further research of new anti-SARS-CoV2 industrial applications of S. nigra.

Biological Actions and Molecular Mechanisms of Sambucus nigra L. in Neurodegeneration: A Cell Culture Approach.

Sambucus nigra flowers (elderflower) have been widely used in traditional medicine for the relief of early symptoms of common cold. Its chemical composition mainly consists of polyphenolic compounds such as flavonoids, hydroxycinnamic acids, and triterpenes. Although the antioxidant properties of polyphenols are well known, the aim of this study is to assess the antioxidant and protective potentials of Sambucus nigra flowers in the human neuroblastoma (SH-SY5Y) cell line using different in vitro approaches. The antioxidant capacity is first evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Cell viability is assessed by the crystal violet method; furthermore, the intracellular ROS formation (DCFH-DA method) is determined, together with the effect on the cell antioxidant defenses: reduced glutathione (GSH) and antioxidant enzyme activities (GPx, GR). On the other hand, mTORC1 hyperactivation and autophagy blockage have been associated with an increase in the formation of protein aggregates, this promoting the transference and expansion of neurodegenerative diseases. Then, the ability of Sambucus nigra flowers in the regulation of mTORC1 signaling activity and the reduction in oxidative stress through the activation of autophagy/mitophagy flux is also examined. In this regard, search for different molecules with a potential inhibitory effect on mTORC1 activation could have multiple positive effects either in the molecular pathogenic events and/or in the progression of several diseases including neurodegenerative ones.

The impact of Sambucus nigra L. extract on inflammation, oxidative stress and tissue remodeling in a rat model of lipopolysaccharide-induced subacute rhinosinusitis.

Rhinosinusitis is a common disorder related to inflammation of paranasal sinuses and nasal cavity mucosa. Herbal medicines could be an option in the treatment of rhinosinusitis due to their anti-inflammatory and anti-oxidative properties. The study aims to investigate the effect of intranasal Sambucus nigra L. subsp. nigra (SN) extract against inflammation, oxidative stress, and tissue remodeling in nasal and sinus mucosa, but also in serum, lungs, and brain, in Wistar rat model of subacute sinonasal inflammation induced by local administration of lipopolysaccharides (LPS), from Escherichia Coli. The cytokines (TNF-α, IL-1ß, IL-6) and oxidative stress (malondialdehyde) in nasal mucosa, blood, lungs, and brain were analyzed. In addition, a histopathological examination was performed, and NF-kB, MMP2, MMP9, TIMP1 expressions were also evaluated in nasal mucosa. Both doses of LPS increased the production of cytokines in all the investigated tissues, especially in the nasal mucosa and blood (p < 0.01 and p < 0.05), and stimulated their secretion in the lungs, and partially in the brain. Malondialdehyde increased in all the investigated tissues (p < 0.01 and p < 0.05). In parallel, upregulation of NF-kB and MMP2 expressions with downregulation of TIMP1, particularly at high dose of LPS, was observed. SN extract reduced the local inflammatory response, maintained low levels of IL-6, TNF-α, and IL-1ß. In lungs, SN reduced all cytokines levels while in the brain, the protective effect was noticed only on IL-6. Additionally, SN diminished lipid peroxidation and downregulated NF-kB in animals exposed to a low dose of LPS, with increased TIMP1 expression, while in animals treated with a high dose of LPS, SN increased NF-kB, MMP2, and MMP9 levels. In conclusion, SN extract diminished the inflammatory response, reduced generation of reactive oxygen species (ROS) and, influenced MMPs expressions, suggesting the benficial effect of SN extract on tissue remodeling in subacute rhinosinusitis and on systemic inflammatory response.

Elderberry Extract Outpatient Influenza Treatment for Emergency Room Patients Ages 5 and Above: a Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Black elderberry, used medicinally for centuries, decreased influenza duration by 4 days in three previous peer-reviewed trials. US elderberry sales, possibly related to a "high severity" and "high activity" influenza season from January to March 2018, more than doubled from 2017 to 2018 to > $100 million. OBJECTIVE: To determine whether elderberry extract decreases influenza's duration and severity. DESIGN: FDA-approved, investigator-initiated, Investigational New Drug, double-blind, randomized, placebo-controlled trial. Conducted January 2018-April 2019 in three emergency rooms, two suburban and one urban, in the Midwestern Health System. PATIENTS: Eighty-seven consecutive, consenting patients, over age four, with < 48 h of at least 2 moderate-severity influenza symptoms and positive polymerase chain reaction influenza test. INTERVENTION: Patients from age 5 to 12 years received placebo or 15 ml (5.7 g) elderberry extract orally twice a day for 5 days; those > 12 years received 15 ml 4 times a day for 5 days. Patients were permitted to choose to also receive the standard dosage of oseltamivir. MEASUREMENTS: Primary: days until all symptoms were none or mild for 21.5 h. Secondary: days to complete symptom resolution for 24 h. RESULTS: The 87 participants were randomized to receive placebo (n = 44) or elderberry (n = 43). The average age was 25 ± 20 years, and 56% were male. The average number of days to reach all symptoms none or mild for 21.5 h in the placebo group was 4.9 ± 2.8 days compared to 5.3 ± 3.6 in the elderberry group (p = 0.57). The average number of days to complete resolution was 8.7 ± 3.8 and 8.6 ± 3.9 in the placebo and elderberry group, respectively (p = 0.87). LIMITATIONS: Small sample size, but powered > 0.90 to detect 2-day benefit of elderberry versus placebo. CONCLUSIONS: We found no evidence that elderberry benefits the duration or severity of influenza. Post hoc analysis suggested primary outcomes with elderberry taken alone (without oseltamivir) were 2 days worse than with placebo taken alone. Our results contradict previous studies and demonstrate the need for further studies. TRIAL REGISTRATION: NCT03410862.

A Green Extraction Process for Polyphenols from Elderberry (Sambucus nigra) Flowers Using Deep Eutectic Solvent and Ultrasound-Assisted Pretreatment.

Sambucus nigra flowers, known as elderberry flowers (EBF), are a plant tissue rich in polyphenolic phytochemicals with important bioactivities. However, there are few studies dealing with the production of polyphenol-containing EBF extracts. The objective of the investigation presented herein was the development of a high-performance green extraction methodology, to generate EBF extracts enriched in polyphenolic substances, using an efficient deep eutectic solvent, combined with ultrasonication pretreatment. The DES was composed of L-lactic acid (hydrogen bond donor-HBD) and glycine (hydrogen bond acceptor-HBA) and, after an initial screening to properly regulate HBD/HBA ratio, the extraction was optimized by deploying response surface methodology. Under the optimized conditions, which were DES/water (85% w/v), liquid-to-solid ratio 60 mL g-1, and stirring speed 200 rounds per minute, the extraction yield in total polyphenols amounted to 121.24 ± 8.77 mg gallic acid equivalents per g dry matter. The integration of ultrasonication prior to the batch stirred-tank extraction boosted polyphenol recovery of up to 174.73 ± 2.62 mg gallic acid equivalents per g dry matter. Liquid chromatography-mass spectrometry analysis showed that the richest EBF extract obtained was dominated by rutin, a di-p-coumaroylquic acid and chlorogenic acid.

Mechanisms in mutualisms: a chemically mediated thrips pollination strategy in common elder.

MAIN CONCLUSION: This study provides first evidence of a thrips species pollinating Sambucus nigra and describes how interactions are driven by plant biochemical signalling and moderated by temporal changes in floral chemistry. The concept of flower-feeding thrips as pollinating insects in temperate regions is rarely considered as they are more frequently regarded to be destructive florivores feeding on pollen and surrounding plant tissue. Combining laboratory and field-based studies we examined interactions between Sambucus nigra (elderflower) and Thrips major within their native range to ascertain the role of thrips in the pollination of this species and to determine if floral chemicals mediated flower visits. If thrips provide a pollination service to S. nigra, then this will likely manifest in traits that attract the pollinating taxa at temporally critical points in floral development. T. major were highly abundant in inflorescences of S. nigra, entering flowers when stigmas were pollen-receptive and anthers were immature. When thrips were excluded from the inflorescences, fruit-set failed. Linalool was the major component of the inflorescence headspace with peak abundance coinciding with the highest number of adult thrips visiting flowers. Thrips were absent in buds and their numbers declined again in senescing flowers inversely correlating with the concentration of cyanogenic glycosides recorded in the floral tissue. Our data show that S. nigra floral chemistry mediates the behaviour of pollen-feeding thrips by attracting adults in high numbers to the flowers at pre-anthesis stage, while producing deterrent compounds prior to fruit development. Taking an integrative approach to studying thrips behaviour and floral biology we provide a new insight into the previously ambiguously defined pollination strategies of S. nigra and provide evidence suggesting that the relationship between T. major and S. nigra is mutualistic.

Reduced α-2,6 sialylation regulates cell migration in endometriosis.

STUDY QUESTION: Is endometriosis associated with aberrant sialylation patterns and what is the potential impact of such anomalies on cell migratory properties? SUMMARY ANSWER: The reduced α-2,6 sialylation patterns in the peritoneal fluid of endometriosis-affected women and in stromal and epithelial cells from endometriotic lesions could be associated with enhanced cell migration. WHAT IS KNOWN ALREADY: Endometriosis is considered to be a benign disease although, like cancer, it has the characteristic of being an invasive disease with cells that have an enhanced capacity to migrate. Aberrant sialylation has been reported in various malignancies and it has been linked to tumour invasion and metastasis. STUDY DESIGN, SIZE, DURATION: We conducted a prospective laboratory study in a tertiary-care university hospital. We investigated non-pregnant patients who were <42 years of age (n = 273) when they underwent surgery for a benign gynaecological condition. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study population consisted of 102 women with histologically proven endometriosis and 71 endometriosis-free controls, who underwent a complete surgical exploration of the abdominopelvic cavity. Peritoneal fluids were collected during the surgical procedures, and endometrial and endometriotic biopsies were performed on all of the patients to generate stromal and epithelial primary cell cultures. The expression of α-2,6-sialyltransferase (ST6GALNAC1) was studied in eutopic and ectopic endometria of endometriosis patients and in eutopic endometria of controls by reverse transcription followed by quantitative real-time polymerase chain reaction (RT-qPCR). The α-2,6 sialylation levels were measured by ELISA in the peritoneal fluids of patients and controls and by western-blot in primary endometrial and endometriotic cell cultures using Sambucus nigra agglutinin (SNA), an α-2,6 sialic acid-binding lectin. A transwell migration assay after incubation of the cells with neuraminidase was also performed to evaluate the impact of desialylation on eutopic endometrial stromal cell migration. MAIN RESULTS AND THE ROLE OF CHANCE: ST6GALNAC1 gene expression was significantly lower in endometriotic lesions compared to that in eutopic endometrium of endometriosis-affected patients and healthy endometrium (16-fold for both; P < 0.01). We observed a significant reduction in SNA levels in the peritoneal fluids of endometriosis-affected women compared to control women (median optic density (OD), 0.257; range, 0.215-0.279 versus median OD, 0.278; range 0.238-0.285; P < 0.01), as well as in stromal (mean OD, 705 907; standard error of the mean (SEM), 141 549 versus mean OD, 1.16 × 106; SEM, 107,271; P < 0.05) and epithelial (mean OD, 485 706; SEM, 179 681 versus mean OD, 1.25 × 106; SEM, 232 120; P < 0.05) ectopic endometriotic cells compared to control eutopic cells, indicating reduced α-2,6 sialylation. Finally, in the transwell migration assay, the eutopic endometrial cells of endometriosis patients migrated significantly more into the lower chamber after incubation with neuraminidase, indicating enhanced migration by these cells after desialylation. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Our control group involved patients operated for benign gynaecological conditions (e.g. tubal infertility, uterine fibroids or ovarian cysts) which may also be associated with altered sialylation patterns. WIDER IMPLICATIONS OF THE FINDINGS: The hyposialylation pattern of endometriotic cells appeared to be associated with enhanced migratory abilities, which might contribute to the establishment of early endometriotic implants. Further research is needed to confirm these findings, as this could lead to new potential therapeutic targets for this complex disorder. STUDY FUNDING AND COMPETING INTEREST(S): No external funding was received and there are no conflicts of interest.