Synthesis of 6,8-diaminopurines via acid-induced cascade cyclization of 5-aminoimidazole precursors and preliminary anticancer evaluation.

Inspired by the pharmacological interest generated by 6-substituted purine roscovitine for cancer treatment, 5-aminoimidazole-4-carboxamidine precursors containing a cyanamide unit were prepared by condensation of 5-amino-N-cyanoimidazole-4-carbimidoyl cyanides with a wide range of primary amines. When these amidine precursors were combined with acids, a fast cascade cyclization occurred at room temperature, affording new 6,8-diaminopurines with the N-3 and N-6 substituents changed relatively to the original positions they occupied in the amidine and imidazole moieties of precursors. The efficacy and wide scope of this method was well demonstrated by an easy and affordable synthesis of 22 6,8-diaminopurines decorated with a wide diversity of substituents at the N-3 and N-6 positions of the purine ring. Preliminary in silico and in vitro assessments of these 22 compounds were carried out and the results showed that 13 of these tested compounds not only exhibited IC50 values between 1.4 and 7.5 µM against the colorectal cancer cell line HCT116 but also showed better binding energies than known inhibitors in docking studies with different cancer-related target proteins. In addition, good harmonization observed between in silico and in vitro results strengthens and validates this preliminary evaluation, suggesting that these novel entities are good candidates for further studies as new anticancer agents.

Cerebral Venous Thrombosis in Pediatric Age: Risk Factors and Prognosis.

INTRODUCTION: Cerebral venous thrombosis (CVT) is a rare but potentially fatal disease in pediatric age with an important morbimortality. In adults several factors have been associated with worse outcomes, however there are still few studies in children. This study aims to identify risk factors associated with clinical manifestations and long-term sequelae in pediatric CVT. METHODS: Retrospective analysis of pediatric inpatients admitted to a tertiary-care hospital due to CVT between 2008 and 2020. RESULTS: Fifty-four children were included, 56% male, median age of 6.5 years (9 months-17.3 years). Permanent risk factors were identified in 13 patients (malignancy, 8; hematologic condition, 5) and transient risk factors in 47, including head and neck infections (57%) and head trauma (15%). Multiple venous sinuses involvement was present in 65% and the deep venous system was affected in four patients. Seventeen percent had intracranial hemorrhage and 9% cerebral infarction. Sixty-four percent of patients with multiple venous sinuses involvement presented with severe clinical manifestations: impaired consciousness, intracranial hypertension, acute symptomatic seizures or focal deficits. Regarding long-term prognosis, six patients had major sequelae: epilepsy (n = 3), sensory motor deficits (n = 2), and cognitive impairment (n = 3). Permanent risk factors were associated with severe clinical manifestations (p = 0.043). Cerebral infarction and intracranial hemorrhage were associated with major sequelae (p = 0.006 and p = 0.03, respectively, adjusted for age and sex). CONCLUSION: Permanent risk factors, involvement of multiple venous sinuses, intracranial hemorrhage, and cerebral infarction, were related to worse prognosis. Detection and early management of risk factors may limit CVT extension and reduce its morbimortality.

Assessment of in vitro digestibility and postdigestion peptide release of mare milk in relation to different management systems and lactation stages.

Mare milk has a unique protein composition that makes it a preferred option for adult and infant nutrition. Several functional properties have been attributed to this milk, but with little current evidence. In fact, knowledge on mare milk composition is still limited. In particular, studies addressing the performance of mare milk proteins during human gastrointestinal digestion are scarce, which limits the understanding of mare milk nutritional quality and functionality. For this reason, the present study describes the digestibility of mare milk proteins and the release of peptides as affected by management and lactation stage, factors which are known to affect milk composition. Mare milk samples from 3 different farms collected during 6 mo of lactation (n = 54) were subjected to a static in vitro gastrointestinal model to measure peptide release and protein digestibility. In the present study, a detailed description of protein and individual amino acid behavior during the digestion process was given. For the first time, digestion of the 2 equine ß-lactoglobulin isoforms (I and II) was described individually. In addition, it was found that lactation stage and management system can significantly affect protein digestibility and peptide release during gastrointestinal digestion of mare milk. Presumably, differences in the composition of mare milk influence the protein structure and enzyme accessibility, which might have an impact on digestion behavior. Although no specific bioactive peptides were identified, several precursors of previously described bioactive peptides were found. These findings could support the idea of mare milk as a food with added value.

Chemical Composition of Extracts and Fractions from Miconia Ibaguensis (Melastomataceae) Leaves and Evaluation of Biological Activities.

The study aimed to assess the chemical composition of Miconia ibaguensis leaves extracts and fractions obtained from the ethanolic extract (EE), along with evaluating their antifungal, antibacterial, antidiabetic, and antioxidant activities. The ethyl acetate fraction (EAF) exhibited potent antifungal activity against Candida spp (1.95-3.90 µg mL-1) and potent antioxidant activity in the DPPH (1.74±0.07 µg mL-1), FRAP (654.01±42.09 µmol ETrolox/gsample), and ORAC (3698.88±37.28 µmol ETrolox/gsample) methods. The EE displayed inhibition against the α-amylase enzyme (8.42±0.05 µg mL-1). Flavonoids, hydrolysable tannins, triterpenoids, and phenolic acids, identified in the EE and fractions via (-)-HPLC-ESI-MS/MS analysis, were found to contribute to the species' biological activity potentially. These findings suggest promising avenues for further research and potential applications in pharmacology and natural products, offering new possibilities in the fight against global health issues.

Chronic pain causes Tau-mediated hippocampal pathology and memory deficits.

Persistent pain has been recently suggested as a risk factor for dementia. Indeed, chronic pain is frequently accompanied by maladaptive brain plasticity and cognitive deficits whose molecular underpinnings are poorly understood. Despite the emerging role of Tau as a key regulator of neuronal plasticity and pathology in diverse brain disorders, the role of Tau has never been studied in the context of chronic pain. Using a peripheral (sciatic) neuropathy to model chronic pain in mice-spared nerve injury (SNI) for 4 months-in wildtype as well as P301L-Tau transgenic mice, we hereby demonstrate that SNI triggers AD-related neuropathology characterized by Tau hyperphosphorylation, accumulation, and aggregation in hippocampus followed by neuronal atrophy and memory deficits. Molecular analysis suggests that SNI inhibits autophagy and reduces levels of the Rab35, a regulator of Tau degradation while overexpression of Rab35 or treatment with the analgesic drug gabapentin reverted the above molecular changes leading to neurostructural and memory recovery. Interestingly, genetic ablation of Tau blocks the establishment of SNI-induced hippocampal morphofunctional deficits supporting the mediating role of Tau in SNI-evoked hippocampal pathology and memory impairment. These findings reveal that exposure to chronic pain triggers Tau-related neuropathology and may be relevant for understanding how chronic pain precipitates memory loss leading to dementia.

A Novel Homozygous Splice Site Variant in AIMP1 Gene Causing Hypomyelinating Leukodystrophy: Case Report and Review of the Literature.

BACKGROUND: Biallelic pathogenic variants in AIMP1 gene cause hypomyelinating leukodystrophy type 3, a severe neurodegenerative disorder with early onset characterized by microcephaly, axial hypotonia, epilepsy, spasticity, and developmental delay. METHODS: Clinical exome sequence was performed on patient's DNA and Sanger sequencing was used to confirm the candidate variant. To better characterize the effect of the genetic variant, functional analysis based on Sanger sequencing of the proband's complementary DNA (cDNA) was performed. RESULTS: We report a case of 2-year-old girl with microcephaly, significant global developmental delay, refractory epilepsy, flaccid paralysis, hypomyelination, leukodystrophy, and cerebral atrophy on brain magnetic resonance imaging (MRI). Clinical exome sequencing revealed a novel splice site variant c.603 + 1G > A in homozygosity in the AIMP1 gene. Studies on patient's cDNA showed that the variant disrupts the canonical donor splice site of intron 5, with the recognition of a cryptic splice site within exon 5, leading to the skipping of the last 24 nucleotides of this exon together with the flanking intron. This alteration is predicted to cause an in-frame deletion of eight amino acids (p.Val194_Gln201del) belonging to the tRNA-biding domain of the protein. CONCLUSION: To the best of our knowledge, this is the first report of a splice site variant in the AIMP1 gene causing hypomyelinating leukodystrophy. The description of this patient not only expands the mutational spectrum of AIMP1 but also provides deeper insights on genotype-phenotype correlation by comparing the clinical features of our patient with previously reported affected individuals.

The role of the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PIGF) - ratio in clinical practice in obstetrics: diagnostic and prognostic value.

OBJECTIVES: Analyze the diagnostic and prognostic value of the sFlt-1/PlGF ratio in pregnant women with at least one sign/symptom of suspected/diagnosed pre-eclampsia. METHODS: This retrospective observational study included 170 pregnant women with at least one sign/symptom of pre-eclampsia, who had sFlt-1/PlGF ratio values. The following information was evaluated: pregnant women's demographic data and clinical history; laboratory data (urine protein/creatinine ratio; sFlt-1/PlGF ratio); signs and symptoms presented; clinical outcome; fetal complications; data related to childbirth. Statistical analysis was performed by R Software Version 3.5.2. RESULTS: Among the 170 patients, 78 presented pre-eclampsia. The median sFlt-1/PlGF ratio was significantly higher [143.1 (2.2-2,927.1)] for women who presented pre-eclampsia than for women without pre-eclampsia [33.5 (0.8-400.2)]. The negative predictive value of sFlt-1/PlGF ratio <38 was 83.9 % (95 % CI, 71.7-92.4 %) and the positive predictive value of sFlt-1/PlGF ratio >85 or 110 (for late onset pre-eclampsia) was 76.4 % (95 % CI, 66.2-84.8 %). sFlt-1/PlGF >85 or 110 was associated with pre-eclampsia clinical development, fetal complications, shorter gestational age at birth, higher number of caesarean deliveries and lower birth weight. CONCLUSIONS: The sFlt-1/PlGF ratio, together with the standard diagnostic criteria, can be used to rule out pre-eclampsia, identify high-risk patients and predict the occurrence of adverse outcomes.

An In Vivo Assessment of the Effect of Hexane Extract from Endlicheria paniculata Branches and Its Main Compound, Methyldehydrodieugenol B, on Murine Sponge-Induced Inflammation.

The present study aims to explore the anti-inflammatory potential activity of the hexane extract from branches (HEB) of Endlicheria paniculata (Lauraceae) and its main compound, methyldehydrodieugenol B, in the inflammatory response induced by a murine implant sponge model. HPLC-ESI/MS analysis of HEB led to the identification of six chemically related neolignans, with methyldehydrodieugenol B as the main compound. An in silico analysis of the pharmacokinetic parameters of the identified compounds suggested moderate solubility but good absorption and biodistribution in vivo. Thus, the treatment of mice with HEB using in vivo assays indicated that HEB promoted pro-inflammatory, antiangiogenic, and antifibrogenic effects, whereas treatment with methyldehydrodieugenol B caused anti-inflammatory, antifibrogenic, and antiangiogenic effects. The obtained results shown the therapeutic potential of HEB and methyldehydrodieugenol B in the treatment of pathologies associated with inflammation and angiogenesis, including chronic wounds.

Sweetpotato Genotypes 'CIP BRS Nuti' and 'Canadense' Are Resistant to Meloidogyne incognita, M. javanica, and M. enterolobii.

Sweetpotato is a staple crop in Brazil presenting a smaller number of pathogens and diseases in comparison with other root and tuberous crops. Root-knot nematodes are among the most serious sweetpotato root pathogens. The impact of these pathogens also extends to succeeding crops. Because in Brazil, it is common to cultivate more than one crop per season, this problem is rapidly disseminated. The aim of this study was to assess the resistance of two sweetpotato clones and four commercial sweetpotato genotypes to three different Meloidogyne species. Assays were performed under greenhouse and field conditions. 'CIP BRS Nuti' and 'Canadense' were resistant to Meloidogyne incognita, M. javanica, and M. enterolobii under greenhouse conditions. This finding was obtained based on the reproduction factor < 0.2, meaning that the initial population of 5,000 nematodes was reduced to <1,000 individuals after 90 days of inoculation. Tomato and sweetpotato cultivar Beauregard, known to be susceptible to the three nematode species, were highly damaged by the pathogens. Similar results were also observed under field conditions. To our knowledge, 'CIP BRS Nuti' and 'Canadense' are the first South American commercial cultivars with triple nematode resistance.

Formulation Effects in the Antioxidant Activity of Extract from the Leaves of Cymbopogon citratus (DC) Stapf.

Cymbopogon citratus DC (Stapf.) is a perennial grass and it is distributed around the world. It is used as a condiment for food and beverage flavouring in the form of infusions and decoctions of its dried leaves. Our previous studies have shown antioxidant, anti-inflammatory and gastroprotective activities for the infusion and its phenolic fractions. The aim of the present work was to develop oral dosage forms from a Cymbopogon citratus extract to be used as a functional food with antioxidant properties. Initially, an essential oil-free infusion was prepared, lyophilized and characterized by HPLC-PDA. Total phenols were quantified with the Folin-Ciocalteu method and the antioxidant activity was assessed by DPPH assay. Gelatine capsules containing the extract with different excipients, selected after DSC and IR trials, were prepared. A formulation exhibiting better antioxidant behaviour in a gastric environment was attained. These results suggest that the proposed formulation for this extract could be a valuable antioxidant product and, consequently, make an important contribution to "preventing" and minimizing diseases related to oxidative stress conditions.

Essential oil from leaves of Eugenia calycina Cambes: Natural larvicidal against Aedes aegypti.

BACKGROUND: Eugenia calycina is an endemic species in the Brazilian savannah (the Cerrado) and it is threatened with extinction. Several species of Eugenia are used as insecticides or insect repellents. No data are available on the larvicidal activity of E. calycina. The chemical composition of the essential oil (EO) from leaves of Eugenia calycina was analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and the larvicidal activity against Aedes aegypti larvae in the third stage of development was studied. RESULTS: Oxygenated and non-oxygenated sesquiterpenes were identified, and the main compounds were bicyclogermacrene, spathulenol, and ß-caryophyllene. The EO was fractionated in a chromatographic column and three compounds were isolated and identified: spathulenol, aromadendrane-4ß,10α-diol, and 1ß-11-dihydroxy-5-eudesmene. It is the first time that the last two compounds have been identified in E. calycina. The exposure times in the larvicidal test were 24 h and 48 h and the LC50 values obtained were 199.3 and 166.4 µg mL-1 . The cytotoxicity of the EO in mammalian cells (HeLa and Vero) was evaluated for 24 and 48 h of incubation. The cytotoxic concentrations of the EO for HeLa and Vero cells (266.8 ± 46.5 and 312.1 ± 42.5 µg mL-1 , respectively) in 48 h of exposure were higher than the LC50 , showing low cytotoxicity at the concentration exhibiting larvicidal activity, resulting in a positive selectivity index. CONCLUSION: These results indicate that the EO of E. calycina showed high activity against the A. aegypti larvae but lower cytotoxicity to mammalian cells. The leaves of E. calycina are therefore a very promising source of natural larvicidal products. © 2020 Society of Chemical Industry.

Antioxidant compounds from Banisteriopsis argyrophylla leaves as α-amylase, α-glucosidase, lipase, and glycation inhibitors.

Banisteriopsis argyrophylla belongs to the Malpighiaceae family, which is a species from Cerrado, also known as "cipó-prata" or "cipó-folha-de-prata." Several species of this family present biological potential. This work reports the chemical identification of the ethanol extract (EE) and its fractions from B. argyrophylla leaves and shows the analysis of the antioxidant activity and inhibitory effects on activities of α-amylase, α-glucosidase and lipase, and non-enzymatic glycation. The ethyl acetate fraction (EAF) and n-butanol fraction (BF) showed antioxidant activity, with IC50 values of 4.1 ± 0.1 and 4.8 ± 0.1 µg mL-1, respectively, by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and IC50 values of 6046.3 ± 174.2 and 6264.2 ± 32.2 µmol Trolox eq g-1 by the oxygen radical absorbance capacity (ORAC) method. Furthermore, the DPPH method with these fractions presented electroactive species with antioxidant potential, as shown by the differential pulse voltammetry (DPV) method. The inhibitory effects of the EAF and BF were demonstrated by the following results: IC50 of 5.1 ± 0.3 and 2.5 ± 0.2 µg mL-1 for α-amylase, IC50 of 1093.5 ± 26.0 and 1250.8 ± 21.9 µg mL-1 for α-glucosidase, IC50 of 8.3 ± 4.1 and 4.4 ± 1.0 µg mL-1 for lipase, and IC50 of 1.3 ± 0.1 and 0.9 ± 0.1 µg mL-1 for glycation. Some bioactive compounds were identified by (-)-ESI-MS/MS, such as catechin, procyanidins, glycosylated flavonoids, kaempferol, and megastigmane glucosides. The antidiabetic activity of B.argyrophylla has been reported for the first time.

Degradation mechanism of fipronil and its transformation products, matrix effects and toxicity during the solar/photo-Fenton process using ferric citrate complex.

This study presents the degradation of fipronil in sewage treatment plant (STP) effluent by photo-Fenton at near neutral pH (pH 6.0) using Fe3+/Citrate complex. 83% of fipronil degradation was reached using a molar iron/citrate ratio of 1:3 (192 µmol L-1 of Fe3+/576 µmol L-1 of citrate). Photo-Fenton reduced the toxicity of treated solutions as according to the survival of Drosophila melanogaster exposed to non-treated and treated samples. Control experiments performed in distilled water using 32 µmol L-1 of Fe3+/96 µmol L-1 of citrate achieved 98% of fipronil degradation within 100 kJ m-2 (UV-A radiation, k = 30 × 10-3 kJ-1 m2 and t1/2 = 23 kJ m-2), thus indicating that fipronil degradation is impaired by natural organic matter and inorganic ions present in STP effluent. Degradation was faster under solar radiation, as the same efficiency (98%) was obtained after 75 kJ m-2 (k = 63 × 10-3 kJ-1 m2 and t1/2 = 11 kJ m-2). In addition, pathways of fipronil degradation using Fe3+/Citrate under solar and UV-A radiation were investigated and transformation products proposed. Results revealed that the HO• attack occurred preferentially in the pyrazole ring. Eight transformation products were identified by UHPLC-Q-TOF-MS and four are unprecedented in the literature. Control experiments in distilled water demonstrated that toxicity reduction is related to fipronil degradation and that transformation products are less toxic than fipronil. Furthermore, toxicity of STP fortified with fipronil was reduced after photo-Fenton. These results demonstrate the feasibility of applying this process using Fe3+/Citrate complex for fipronil degradation in a real matrix.

Optimization of nimesulide-loaded solid lipid nanoparticles (SLN) by factorial design, release profile and cytotoxicity in human Colon adenocarcinoma cell line.

The aim of this work is development of a nontoxic, long-term stable solid lipid nanoparticles (SLN) formulation for the loading of Nimesulide (NiM) by a 22 factorial design. The optimized formulation was composed of 10 wt% of glyceryl behenate and 2.5 wt% of poloxamer 188. Immediately after production, Z-Ave of NiM-SLN was 166.1 ± 0.114 nm, with a polydispersity index (PI) of 0.171 ± 0051 and zeta potential nearly neutral (-3.10 ± 0.166 mV). A slight increase of Z-Ave was recorded for NiM-SLN stored at 25 °C for a period of 15 days, whereas at 4 °C particles kept size within similar range. Long-term stability was monitored using TurbiscanLab®, showing a high stability of the nanoparticles with variations in the backscattering profiles below 10%. The release profile of NiM-SLN followed a sustained pattern with ca. 30% of drug released up to 24 h. Empty-SLN and NiM-SLN were nontoxic after exposing Caco-2 cells to the highest concentration (100 µg/mL) up to 48 hours (cell viability higher than 80%). NiM-SLN were lyophilized using different cryoprotectants, producing particles of 463.1 ± 36.63 nm (PI 0.491 ± 0.027) with 5% trehalose. Solid character of NiM-SLN was confirmed by DSC, recording a recrystallization index of 83% for NiM-SLN and of 74% for lyophilized SLN.

Integrating coagulation-flocculation and UV-C or H2O2/UV-C as alternatives for pre- or complete treatment of biodiesel effluents.

The feasibility of biodiesel effluent treatment combining coagulation-flocculation with a photolytic process was evaluated, being the photolytic process involving the irradiation of the effluent by UV-C, or by UV-C irradiation with simultaneous addition of H2O2 (H2O2/UV-C). The coagulation-flocculation was performed at the natural pH of the effluent (pH 2.9) using different Fe3+ salts (chloride, nitrate and sulfate) at different concentrations (0.25, 0.50 and 1.0 mmol L-1) of the counterions. The best results were achieved using 0.50 mmol L-1 Fe(NO3)3. Following, the degradation of the organic load and toxicity reduction of the pre-treated effluent by UV-C irradiation was evaluated. The H2O2/UV-C process showed to be advantageous, mainly when multiple additions of H2O2 were used during the course of the reaction. Additionally, the influence of the initial pH on the degradation was also evaluated. A high level of mineralization (94%) was achieved after 6 h of irradiation concomitantly with multiple additions of 2,000 mg L-1 H2O2, and with the effluent at the natural pH. Thus, using coagulation-flocculation followed by the H2O2/UV-C process, it was possible to achieve a favourable condition for reuse of the pre-treated effluent, since, in addition to the significant reduction of the organic load, the final DBO5 (<120 mg L-1) and oils & fats (<50 mg L-1) are below the limits established by the Brazilian legislation. Furthermore, a reduction of 78% of acute toxicity to V. fischeri (from 89% to 20%) was reached. The results suggest, therefore, that this process is a viable option for treatment of this kind of effluent.

Peel of araticum fruit (Annona crassiflora Mart.) as a source of antioxidant compounds with α-amylase, α-glucosidase and glycation inhibitory activities.

Annona crassiflora Mart., whose fruit is popularly known as araticum, is a member of the Annonaceae family found in the Brazilian Cerrado. Although this plant has several medicinal uses, its bioactive molecules are not fully understood. A bioguided assay was performed to identify the main bioactive compounds of A. crassiflora fruit peel from the ethanol extract fractions with antioxidant capacity and α-amylase, α-glucosidase and glycation inhibitory activities. Ethyl acetate and n-butanol fractions showed, respectively, higher antioxidant capacity (DPPH IC50 1.5±0.1 and 0.8±0.1µgmL-1, ORAC 3355±164 and 2714±79µmoltroloxeq/g, and FRAP 888±16 and 921±9µmoltroloxeq/g) and inhibitory activities against α-amylase (IC50 4.5±0.8 and 1.7±0.3µgmL-1), α-glucosidase (IC50 554.5±158.6 and 787.8±140.6µgmL-1) and glycation (IC50 14.3±3.3 and 16.0±4.2µgmL-1), and lower cytotoxicity, compared to the other fractions and crude ethanol extract. The HPLC-ESI-MS/MS analysis identified various biomolecules known as potent antioxidants, such as chlorogenic acid, (epi)catechin, procyanidins, caffeoyl-hexosides, quercetin-glucosides and kaempferol. The fruit peel of A. crassiflora, a specie from Cerrado, the Brazilian Savanna, provided a source of antioxidant compounds with properties to block carbohydrate digestive enzymes and formation of glycation products. Thus, there is potential to use the by-products of araticum in order to identify and isolate phytochemicals for application in nutraceutical supplements, food additives and pharmaceuticals products.

Antiparasitic activity of natural and semi-synthetic tirucallane triterpenoids from Schinus terebinthifolius (Anacardiaceae): structure/activity relationships.

Leishmaniasis and Chagas are diseases caused by parasitic protozoans that affect the poorest population in the World, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, the discovery of novel, safe and more efficacious drugs is essential. In this work, the in vitro antiparasitic activity and mammalian cytotoxicity of three natural tirucallane triterpenoids, isolated from leaves of Schinus terebinthifolius (Anacardiaceae), and nine semi-synthetic derivatives were investigated against Leishmania (L.) infantum and Trypanosoma cruzi. Trypomastigotes of T. cruzi were the most susceptible parasites and seven compounds demonstrated a trypanocidal activity with IC50 values in the range between 15 and 58 µg/mL. Four compounds demonstrated selectivity towards the intracellular amastigotes of Leishmania, with IC50 values in the range between 28 and 97 µg/mL. The complete characterization of triterpenoids was afforded after thorough analysis of nuclear magnetic resonance (NMR) data as well as electrospray ionization mass spectrometry (ESI-MS). Additionally, structure-activity relationships were performed using Decision Trees.

Changes in the IgE-reacting protein profiles of Acer negundo, Platanus x acerifolia and Quercus robur pollen in response to ozone treatment.

This study aims to investigate the effects of O3 in protein content and immunoglobulin E (IgE)-binding profiles of Acer negundo, Platanus x acerifolia and Quercus robur pollen. Pollen was exposed to O3 in an environmental chamber, at half, equal and four times the limit value for the human health protection in Europe. Pollen total soluble protein was determined with Coomassie Protein Assay Reagent, and the antigenic and allergenic properties were investigated by SDS-PAGE and immunological techniques using patients' sera. O3 exposure affected total soluble protein content and some protein species within the SDS-PAGE protein profiles. Most of the sera revealed increased IgE reactivity to proteins of A. negundo and Q. robur pollen exposed to the pollutant compared with the non-exposed one, while the opposite was observed in P. x acerifolia pollen. So, the modifications seem to be species dependent, but do not necessarily imply that increase allergenicity would occur in atopic individuals.