Development of a Nanoformulation for Oral Protein Administration: Characterization and Preclinical Orofacial Antinociceptive Effect

Nanoencapsulation is a valid alternative for the oral administration of peptide drugs and proteins, as nanoparticles protect them from proteolytic degradation in the gastrointestinal tract and promote the absorption of these macromolecules. The orofacial antinociceptive effect of frutalin (FTL), through the intraperitoneal route, has already been proven. This study aimed to develop, characterize, and evaluate the orofacial antinociceptive activity of an oral formulation containing FTL in acute and neuropathic preclinical tests. Nanoencapsulated FTL was administered by oral route. The acute nociceptive behavior was induced by administering capsaicin to the upper lip and NaCl to the right cornea. The nociceptive behavior was also induced by formalin injected into the temporomandibular joint. The neuropathic pain model involved infraorbital nerve transection (IONX), which induced mechanical hypersensitivity and was assessed by von Frey stimulation. Trpv1 gene expression was analyzed in the trigeminal ganglion. The analyzed sample did not show any cytotoxicity; 52.2% of the FTL was encapsulated, and the size of the nanocapsule was less than 200 nm, the polydispersion was 0.361, and the zeta potential was - 5.87 and - 12.8 mV, with and without FTL, respectively. Nanoencapsulated FTL administered by oral route had an orofacial antinociceptive effect in acute and neuropathic rodent models. The antinociceptive effect of FTL was prevented by ruthenium red, but not by camphor. FTL reduced Trpv1 gene expression. FTL promotes orofacial antinociception, probably due to the antagonism of TRPV1 channels, and the nanoformulation represents an effective method for the oral administration of this protein. HIGHLIGHTS: • Nanoformulation for oral protein administration. • Nanocapsule containing FTL prevents orofacial nociceptive acute and neuropathic pain. • Frutalin promotes orofacial antinociception behavior antagonism of TRPV1 channels.

Dioclea Altissima Seed Lectin (DAL) Prevents Anxiety-like Behavioral Responses in Adult Zebrafish (Danio Rerio): Involvement of GABAergic and 5-HT Systems

BACKGROUND

Plant lectins have shown promising neuropharmacological activities in animal models.

OBJECTIVE

This study evaluated the effect of Dioclea altissima seed lectin (DAL) on adult zebrafish behavior.

METHOD

Zebrafish (n=6/group) were treated (i.p.; 20 μL) with DAL (0.025; 0.05 or 0.1 mg/mL), vehicle or diazepam (DZP) and submitted to several tests (open field, light/dark preference or novel tank). Flumazenil, pizotifen or granisetron were administered 15 min before DAL (0.05 mg/mL), and the animals were evaluated on light/dark preference test. It was also verified whether the DAL effect depended on its structural integrity and ability to interact with carbohydrates.

RESULTS

DAL decreased the locomotor activity of adult zebrafish (0.025; 0.05 or 0.1 mg/mL), increased the time spent in the upper region of the aquarium (0.025 mg/mL), and decreased the latency time of adult zebrafish to enter the upper region on the novel tank test. DAL (0.05 mg/mL) also increased their permanence in the light zone of the light/dark preference test. The effect of DAL was dependent on carbohydrate interaction and protein structure integrity and was prevented by pizotifen, granizetron and flumazenil.

CONCLUSION

DAL was found to have an anxiolytic-like effect mediated by the 5-HT and GABAergic receptors.

Pyrodextrinization of yam (Dioscorea sp.) starch isolated from tubers grown in Brazil and physicochemical characterization of yellow pyrodextrins

This study optimizes the pyrodextrinization of yam (Dioscorea sp.) starch isolated from tubers grown in Brazil to produce a yellow pyrodextrin with the lowest enzymatically available starch (AS) content and color difference (ΔE) index. At 140 °C (fixed heating temperature), the effects of acid concentration (0.65 - 2.99 g of HCl/kg of starch) and incubation time (53 - 307 min) on the response variables were evaluated using a response surface methodology. Some physicochemical characteristics were also determined on pyrodextrins. Both factors negatively affected the AS content, although positively influenced the ΔE (P < 0.05). The yellow pyrodextrin produced with 1.82 g/kg and heating for 307 min, presented physicochemical properties similar to the commercial pyrodextrins from potato starch, with 46.6 % of AS, 24.5 of ΔE, high solubility and very low viscosity. The pyrodextrinization caused a decrease of 30 - 54 % in AS content (P < 0.05), making these yam pyrodextrins a promising material for water-soluble and very low viscous dietary fiber.

Neuropharmacological Characterization of Dioclea altissima Seed Lectin (DAL) in Mice: Evidence of Anxiolytic-like Effect Mediated by Serotonergic, GABAergic Receptors and NO Pathway

BACKGROUND

Plant lectins have shown promising biological activities in the central nervous system (CNS).

OBJECTIVE

This study evaluated the effect of DAL, a lectin isolated from the seeds of the Dioclea altissima species, having binding affinity to D-glucose or D-mannose residues, on mice behavior.

METHODS

Mice (n=6/group) were treated (i.p.) with DAL (0.25, 0.5 or 1 mg/kg) or vehicle and subjected to several tests (open field/OFT, marble-burying/MBT, hole-board/HBT, elevated plus maze/PMT, tail suspension/ TST, forced swimming/FST or rotarod/RRT). Pizotifen, cyproheptadine, flumazenil, L-NAME, 7-NI, Larginine or yohimbine were administered 15 min before DAL (0.5 mg/kg) and the animals were evaluated on PMT. It was also verified whether the DAL effect depended on its structural integrity and ability to interact with carbohydrates.

RESULTS

The results showed there were no neurobehavioral changes in the mice at the RRT, FST and locomotion in the OFT. DAL (0.25, 0.5 or 1 mg/kg) increased the behavior of grooming and rearing in the OFT, head dips in the HBT, pedalling in the TST and decreased the number of marbles hidden in the MBT. In the PMT, DAL (0.25, 0.5 and 1 mg/kg) and Diazepam increased the frequency of entries in the open arms and the time of permanence in the open arms without affecting the locomotor activity. The effect of DAL was dependent on carbohydrate interaction and protein structure integrity and it prevented by pizotifen, cyproheptadine, flumazenil, L-NAME and 7-NI, but not by L-arginine or yohimbine.

CONCLUSION

DAL was found to have an anxiolytic-like effect mediated by the 5-HT and GABAergic receptors and NO pathway.

Proteins Involved in the Induction of Procoagulant Activity and Autoimmune Response in Patients With Primary Antiphospholipid Syndrome

The aim of this study was to determine the plasma protein profile of patients with primary antiphospholipid syndrome (PAPS) compared to healthy controls and identify proteins that might be used in the evaluation, diagnosis, and prognosis of this condition. The sample consisted of 14 patients with PAPS and 17 sex- and age-matched controls. Plasma samples were submitted to proteomic analysis (albumin and immunoglobulin G depletion, concentration, digestion, and label-free data-independent mass spectrometry). The software ExpressionE was used to quantify intergroup differences in protein expression. The analysis yielded 65 plasma proteins of which 11 were differentially expressed (9 upregulated and 2 downregulated) in relation to controls. Four of these are known to play a role in pathophysiological mechanisms of thrombosis: fibrinogen α chain, fibrinogen α chain, apolipoprotein C-III, and α-1-glycoprotein-1. Our analysis revealed autoimmune response and the presence of proteins believed to be functionally involved in the induction of procoagulant activity in patients with PAPS. Further studies are necessary to confirm our findings and may eventually lead to the development of significantly more accurate diagnostic tools.

Expression of a recombinant bacterial L-asparaginase in human cells

Objective

l-Asparaginase (ASNase) is an enzyme used in the treatment of acute lymphoblastic leukemia (ALL). As the therapeutic ASNases has bacterial origin, severe side effects are associated with its use, among them hypersensitivity and inactivation of the enzyme. In this context, the objective of this work was to produce a recombinant ASNase of bacterial origin in human cells in order to determine the presence and consequences of potential post-translational modifications on the enzyme.

Results

Recombinant ASNase was expressed in human cells with a molecular weight of 60 kDa, larger than in Escherichia coli, which is 35 kDa. N-glycosylation analysis demonstrated that the increased molecular weight resulted from the addition of glycans to the protein by mammalian cells. The glycosylated ASNase presented in vitro activity at physiological pH and temperature. Given that glycosylation can act to reduce antigenicity by masking protein epitopes, our data may contribute to the development of an alternative ASNase in the treatment of ALL in patients who demonstrate side effects to currently marketed enzymes.

Animal Galectins and Plant Lectins as Tools for Studies in Neurosciences

Lectins are proteins or glycoproteins of non-immunological origin capable of reversibly and specifically binding to glycoconjugates. They exist in free form or associated with cells and are widely distributed in nature, being found in plants, microorganisms, and animals. Due to their characteristics and mainly due to the possibility of reversible binding to glycoconjugates, lectins have stood out as important tools in research involving Neurobiology. These proteins have the ability to modulate molecular targets in the central nervous system (CNS) which may be involved with neuroplasticity, neurobehavioral effects, and neuroprotection. The present report integrates existing information on the activity of animal and plant lectins in different areas of Neuroscience, presenting perspectives to direct new research on lectin function in the CNS, providing alternatives for understanding neurological diseases such as mental disorders, neurodegenerative, and neuro-oncological diseases, and for the development of new drugs, diagnoses and therapies in the field of Neuroscience.

Biological Activities and Pharmacological Applications of Cyclodextrins Complexed with Essential Oils and Their Volatile Components: A Systematic Review

BACKGROUND

Essential oils (EOs) and their volatile components (VCs) have varied biological and pharmacological activities, but low solubility and bioavailability hamper their applications, so that inclusion in cyclodextrins (CDs) is likely to improve their physicochemical properties and pharmacological effects.

OBJECTIVE

The authors conducted a systematic review to evaluate the biological activities and pharmacological applications of essential oils and their volatile components complexed with cyclodextrins.

METHODS

The search terms 'Cyxlodextrin', 'Inclusion Complex', 'Volatile oils', 'Essential oil' and 'Volatile components' were used to retrieve articles from the PUBMED, MEDLINE and SCOPUS databases.

RESULTS

A total of 38 articles were identified. A greater efficacy of EOs and their VCs complexed with different CDs types was found in in vitro and preclinical studies when compared to free forms in the various biological activities and animal models of the evaluated pharmacological tests.

CONCLUSION

This review of selected studies showed that the use of CDs promotes greater solubility, bioavailability and efficacy of EOs and their VCs, thus indicating an interesting alternative for the biotechnological development of new therapeutic formulations.

Neuropharmacological characterization of frutalin in mice: Evidence of an antidepressant-like effect mediated by the NMDA receptor/NO/cGMP pathway

In this study we evaluated the effect of frutalin (FTL) on mouse behavior. Mice (n=6/group) were treated (i.p.) with FTL (0.25; 0.5 or 1mg/kg) or vehicle and submitted to several tests (hole-board/HBT, elevated plus maze/PMT, open field/OFT, tail suspension/TST, or forced swimming/FST). Yohimbine, ketamine, l-NAME, aminoguanidine, 7-NI, methylene blue, l-arginine or dl-serine was administered 30min before FTL (0.5mg/kg). To evaluate the subchronic effect, animals were injected with FTL or vehicle for 7days and submitted to the FST. Molecular docking was simulated using FTL against NOS and the NMDA receptor. No changes were observed in the HBT or the OFT. FTL (0.25mg/kg) increased the number of entries into enclosed arms in the PMT. FTL reduced immobility in the TST (0.25 and 0.5mg/kg) and the FST (0.25mg/kg; 0.5mg/kg). The effect of FTL was dependent on carbohydrate interaction and protein structure integrity and was reduced by ketamine, l-NAME, aminoguanidine, 7-NI and methylene blue, but not by l-arginine, yohimbine or dl-serine. The antidepressant-like effect remained after subchronic treatment. The molecular docking study revealed a strong interaction between FTL and NOS and NMDA. FTL was found to have an antidepressant-like effect mediated by the NMDA receptor/NO/cGMP pathway.

Label-Free Proteome Analysis of Plasma from Patients with Breast Cancer: Stage-Specific Protein Expression

Breast cancer is one of the most commonly diagnosed types of cancer among women. Breast cancer mortality rates remain high probably because its diagnosis is hampered by inaccurate detection methods. Since changes in protein expression as well as modifications in protein glycosylation have been frequently reported in cancer development, the aim of this work was to study the differential expression as well as modifications of glycosylation of proteins from plasma of women with breast cancer at different stages of disease (n = 30) compared to healthy women (n = 10). A proteomics approach was used that depleted albumin and IgG from plasma followed by glycoprotein enrichment using immobilized Moraceae lectin (frutalin)-affinity chromatography and data-independent label-free mass spectrometric analysis. Data are available via ProteomeXchange with identifier PXD003106. As result, 57,016 peptides and 4,175 proteins among all samples were identified. From this, 40 proteins present in unbound (PI—proteins that did not interact with lectin) and bound (PII—proteins that interacted with lectin) fractions were differentially expressed. High levels of apolipoprotein A-II were detected here that were elevated significantly in the early and advanced stages of the disease. Apolipoprotein C-III was detected in both fractions, and its level was increased slightly in the PI fraction of patients with early-stage breast cancer and expressed at higher levels in the PII fraction of patients with early and intermediate stages. Clusterin was present at higher levels in both fractions of patients with early and intermediate stages of breast cancer. Our findings reveal a correlation between alterations in protein glycosylation, lipid metabolism, and the progression of breast cancer.

A panel of glycoproteins as candidate biomarkers for early diagnosis and treatment evaluation of B-cell acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia is the most common malignant cancer in childhood. The signs and symptoms of childhood cancer are difficult to recognize, as it is not the first diagnosis to be considered for nonspecific complaints, leading to potential uncertainty in diagnosis. The aim of this study was to perform proteomic analysis of serum from pediatric patients with B-cell acute lymphoblastic leukemia (B-ALL) to identify candidate biomarker proteins, for use in early diagnosis and evaluation of treatment.

METHODS

Serum samples were obtained from ten patients at the time of diagnosis (B-ALL group) and after induction therapy (AIT group). Sera from healthy children were used as controls (Control group). The samples were subjected to immunodepletion, affinity chromatography with α-d-galactose-binding lectin (from Artocarpus incisa seeds) immobilized on a Sepharose(TM) 4B gel, concentration, and digestion for subsequent analysis with nano-UPLC tandem nano-ESI-MS(E). The program Expression (E) was used to quantify differences in protein expression between groups.

RESULTS

A total of 96 proteins were identified. Leucine-rich alpha-2-glycoprotein 1 (LRG1), Clusterin (CLU), thrombin (F2), heparin cofactor II (SERPIND1), alpha-2-macroglobulin (A2M), alpha-2-antiplasmin (SERPINF2), Alpha-1 antitrypsin (SERPINA1), Complement factor B (CFB) and Complement C3 (C3) were identified as candidate biomarkers for early diagnosis of B-ALL, as they were upregulated in the B-ALL group relative to the control and AIT groups. Expression levels of the candidate biomarkers did not differ significantly between the AIT and control groups, providing further evidence that the candidate biomarkers are present only in the disease state, as all patients achieved complete remission after treatment.

CONCLUSION

A panel of protein biomarker candidates has been developed for pre-diagnosis of B-ALL and also provided information that would indicate a favorable response to treatment after induction therapy.

Crystallization and preliminary X-ray diffraction studies of frutalin, an α-D-galactose-specific lectin from Artocarpus incisa seeds

Frutalin is an α-D-galactose-specific carbohydrate-binding glycoprotein with antitumour properties and is a powerful tool for tumour biomarker discovery. The crystallization and preliminary X-ray diffraction analysis of this lectin, which was isolated from Artocarpus incisa seeds, are reported here. Frutalin was purified and submitted to mass-spectrometric analysis. Diverse masses at approximately 16 kDa were observed in the deconvoluted spectra, which support the presence of isoforms. The best frutalin crystals were grown within a week in 0.1 M citric acid pH 3.5 which contained 25% PEG 3350 as a precipitant at 293 K, and diffracted to a maximum resolution of 1.81 Å. The monoclinic crystals belonged to space group I2, with unit-cell parameters a = 76.17, b = 74.56, c = 118.98 Å, β = 96.56°. A molecular-replacement solution was obtained which indicated the presence of four monomers per asymmetric unit. Crystallographic refinement of the structure is in progress.

Crystallization and X-ray diffraction analysis of an antifungal laticifer protein

An osmotin (CpOsm) from the latex of Calotropis procera has been crystallized in both tetragonal and trigonal forms suitable for structure determination. Crystallographic studies of CpOsm are of great interest because limited information is available concerning the structure of latex proteins and CpOsm has previously been shown to interact with the spore membranes of some plant pathogenic fungi, thus impairing spore germination and hyphal growth. CpOsm crystals were grown using 0.1 M HEPES buffer pH 7.5, 26% PEG 4000, 0.2 M ammonium sulfate (space group P4(3)) or using 0.1 M HEPES buffer pH 7.5, 35% MPD, 0.7 M ammonium sulfate (space group P3(1)12). X-ray diffraction data were collected to 2.17 Å (P4(3)) and 1.80 Å (P3(1)12) resolution and molecular-replacement analyses produced initial phases for both crystal forms.

Isolation of a lectin and a galactoxyloglucan from Mucuna sloanei seeds

A lectin and a galactoxyloglucan were characterized from Mucuna sloanei seed cotyledons. The galactoxyloglucan, isolated by water extraction and ethanol precipitation, had Glc:Xyl:Gal proportions in a molar ratio of 1.8:1.7:1.0 and a molar mass (M(w)) of 1.6x10(6)g mol(-1). The lectin (sloanin), isolated from the same seed by affinity chromatography on cross-linked Adenanthera pavonina galactomannan, gave two protein bands by SDS-PAGE (36 and 34 kDa) and one peak by gel filtration (63.6 kDa). Its N-terminal sequence indicated approximately 69% identity with soybean agglutinin to leguminous lectins. Circular dichroism (CD) spectra established that sloanin predominantly contains beta-sheet structures. Sloanin has approximately 5.5% carbohydrate and displayed hemagglutinating activity against rabbit and enzyme treated human erythrocytes, inhibited only by D-Gal containing sugars. The interaction between sloanin and storage cell-wall galactoxyloglucan was tested by affinity chromatography and fluorescence spectroscopy.

Establishment of a heterologous system for the expression of Canavalia brasiliensis lectin: a model for the study of protein splicing

During its biosynthesis in developing Canavalia brasiliensis seeds, the lectin ConBr undergoes a form of protein splicing in which the order of the N- and C-domains of the protein is reversed. To investigate whether these events can occur in other eukaryotic organisms, an expression system based on Pichia pastoris cells was established. A DNA fragment encoding prepro-ConBr was cloned into the vector pPICZB, and the recombinant plasmid was transformed in P. pastoris strain GS115. Ten clones were screened for effective recombinant protein production. Based on Western blot analysis of the two clones with the highest level of protein expression: 1) diffuse high-molecular mass immunoreactive bands were produced as early as 24 h after induction; 2) a single-, high-molecular mass protein was secreted into the medium, and 3) a significant fraction of the recombinant polypeptides that cross-reacted with anti-ConBr antibodies comprised a band of approximately 34.5 kDa. Diffuse protein bands with high molecular masses are attributed to hyperglycosylation at the single potential N-glycosylation site located in the linker peptide of prepro-ConBr. In contrast, native ConBr is made up of three polypeptides, the intact alpha chain (aa 1-237) and the fragments beta (aa 1-118) and gamma (aa 119-237), which have apparent molecular masses of 30, 16 and 12 kDa, respectively. Apparently, the yeast P. pastoris is not able to carry out all the complex post-translational proteolytic processing necessary for the biosynthesis of ConBr.

Proline accumulation and glutamine synthetase activity are increased by salt-induced proteolysis in cashew leaves

In this study cashew (Anacardium occidentale) plants were exposed to a short- and long-term exposure to NaCl in order to establish the importance of the salt-induced proteolysis and the glutamine synthetase activity on the proline accumulation. The cashew leaf showed a prominent proline accumulation in response to salt stress. In contrast, the root tissue had no significant changes in proline content even after the drastic injury caused by salinity on the whole plant. The leaf proline accumulation was correlated to protease activity, accumulation of free amino acid and ammonia, and decrease of both total protein and chlorophyll contents. The leaf GS activity was increased by the salt stress whereas in the roots it was slightly lowered. Although the several amino acids in the soluble pool of leaf tissue have showed an intense increment in its concentrations in the salt-treated plants, proline was the unique to show a proportional increment from 50 to 100 mol m-3 NaCl exposure (16.37 to 34.35 mmol kg-1 DM, respectively). Although the leaf glutamate concentration increased in the leaves of the salt-stressed cashew plants, as compared to control, its relative contribution to the total amino acid decreased significantly in stressed leaves when compared to other amino acids. In addition, when the leaf discs were incubated with NaCl in the presence of exogenous precursors (Glu, Gln, Orn or Arg) involved in the proline synthesis pathways, the glutamate was unique in inducing a significant enhancement of the proline accumulation compared to those discs with precursor in the absence of NaCl. These results, together with the salt-induced increase in the GS activity, suggest an increase in the de novo synthesis of proline probably associated with the increase of the concentration of glutamate. Moreover, the prominent salt-induced proline accumulation in the leaves was associated with the higher salt-sensitivity in terms of proteolysis and salt-induced senescence as compared to the roots. In conclusion, the leaf-proline accumulation was due, at least in part, to the increase in the salt-induced proteolysis associated with the increments in the GS activity and hence the increase in the concentration of glutamate precursor in the soluble amino acid pool.

Cashew-tree (Anacardium occidentale L.) exudate gum: a novel bioligand tool

The potential of bioaffinity as a tool for the study of biological-recognition mechanisms is gaining increasing value. The search continues for alternative products that can be obtained from renewable sources, such as the bark exudate gum from the cashew tree (Anacardium occidentale L.), which grows wild in many tropical and subtropical countries. Its potential use as a chromatographic matrix and/or for bioaffinity ligand for proteins (lectins) has been investigated. The crude gum was cross-linked in order to obtain a kind of chromatographic matrix (gel). To evaluate the gum's ability to retain glycoproteins (lectins), affinity chromatography was performed and, in addition, the reological behaviour of the gum was characterized.