In Silico Design of an Oseltamivir Derivative with Increased Affinity against Wild-Type and Mutant Variants of Neuraminidase and Hemagglutinin of Influenza A H1N1 Virus.

Antiviral resistance has turned into a world concern nowadays. Influenza A H1N1 emerged as a problem at the world level due to the neuraminidase (NA) mutations. The NA mutants conferred resistance to oseltamivir and zanamivir. Several efforts were conducted to develop better anti-influenza A H1N1 drugs. Our research group combined in silico methods to create a compound derived from oseltamivir to be tested in vitro against influenza A H1N1. Here we show the results of a new compound derived from oseltamivir but with specific chemical modifications, with significant affinity either on NA (in silico and in vitro assays) or HA (in silico) from influenza A H1N1 strain. We include docking and molecular dynamics (MD) simulations of the oseltamivir derivative at the binding site onto NA and HA of influenza A H1N1. Additionally, the biological experimental results show that oseltamivir derivative decreases the lytic-plaque formation on viral susceptibility assays, and it does not show cytotoxicity. Finally, oseltamivir derivative assayed on viral NA showed a concentration-dependent inhibition behavior at nM, depicting a high affinity of the compound for the enzyme, corroborated with the MD simulations results, placing our designed oseltamivir derivative as a potential antiviral against influenza A H1N1.

UHPLC-MS/MS Studies and Antiproliferative Effects in Breast Cancer Cells of Mexican Sargassum.

BACKGROUND: Sargassum is a marine organism that, under specific conditions, drastically increases its population damaging the environment and risking other organisms. However, sargassum could represent a source of bioactive compounds to treat different diseases such as cancer. Thus, aqueous, ethanolic, and ethyl acetate extracts of sargassum from Playa del Carmen, Mexico, were subjected to metabolomic and antiproliferative assays in breast cancer cells. OBJECTIVE: To evaluate the biological effect of different extracts of sargassum, its toxicity over Artemia salina and its antiproliferative effect tested in MCF-7, MDA-MB-231, and NIH3T3 cell lines. Finally, using UHPLC-MS/MS to identify the metabolites in each extract to correlate them with its antiproliferative effect. METHODS: The sargassum sample collection was carried out in September at three different points in Playa del Carmen, Quintana Roo, Mexico. The aqueous, ethanolic, and ethyl acetate extracts of Mexican sargassum were obtained by evaporation of solvent and lyophilization. Then, these extracts were evaluated in the cytotoxicity bioassay of Artemia salina. Next, its antiproliferative effect was assessed in MCF-7, MDA-MB-231, and NIH3T3 cell lines. Using UHPLC-MS/MS, the metabolites present in each extract were identified. Finally, docking studies on sphingosine kinase 1 (PDB ID: 3VZB) of sphingosine were carried out. RESULTS: The extracts from sargassum showed a greater effect in the antiproliferative assays in cells than in cytotoxic assays in Artemia salina. The ethanolic extract obtained from sargassum showed the best antiproliferative activity in MCF7 and MDA-MB-231 cells. Despite its antiproliferative effect on NIH3T3 cells, an additional extract is required indicating that this extract has compounds that could have a better effect on cancer cells in fibroblast (NIH3T3). The UHPLC-MS/MS of ethanolic and the ethyl acetate extract showed that these extracts have compounds such as sphinganine C16, N, N-Dimethylsphingosine compound, and that it could be possible that the effect observed is due to their metabolites which could be ligands for the sphingosine kinase 1 as demonstrated by docking studies. CONCLUSION: The ethanolic extract obtained from sargassum has better antiproliferative activity, despite not having a cytotoxic effect in Artemia salina. The antiproliferative effect could be related to the sphinganine C16, N,NDimethylphingosine identified with more abundance by UHPLC-MS/MS. In addition, these metabolites could be targets of sphingosine kinase 1.

Effect of Norelgestromin and Ethinylestradiol in Transdermal Patches on the Clinical Outcomes and Biochemical Parameters of COVID-19 Patients: A Clinical Trial Pilot Study.

The disease caused by SARS-CoV-2 is still considered a global pandemic. Transdermal patches (TP) with immunoregulators such as estrogen and progesterone compounds could be a feasible option to treat COVID-19 because of their accessibility and relative safety. The objective of the current study was to evaluate the additional treatment with norelgestromin and ethinylestradiol in TP on the clinical and biochemical evolution of COVID-19 patients. The present is a clinical-trial pilot study that included subjects diagnosed with COVID-19, randomized into two groups; the experimental Evra® TP (norelgestromin 6 mg and ethinylestradiol 0.60 mg) was administered such that it was applied on arrival and replaced at day 8 and day 15. The control continued with the conventional COVID-19 treatment protocol. A blood sample was taken each week in order to evaluate relevant biochemical parameters, clinical signs, and evolution. In total, 44 subjects participated in this study, 30 in the experimental group and 14 in the control group. Both groups were homogeneous in terms of age and comorbidities. The experimental group had a significantly lower hospital stay (p = 0.01), high flow supplemental oxygen (p = 0.001), mechanical ventilation (p = 0.003), and intubation (p = 0.01), and the oxygen saturation significantly increased (p = 0.01) in comparison with control group when patients were exposed to room air. A decrease in ferritin (p < 0.05) was observed, with no significant increase in ESR (p > 0.05), D dimer (p > 0.05) and platelets (p > 0.05) in an auto-controlled analysis in the experimental group. Norelgestromin and ethinylestradiol TP could be a safe and effective treatment for moderate and severe COVID-19 patients.

Immunoinformatics study to search epitopes of spike glycoprotein from SARS-CoV-2 as potential vaccine.

The Coronavirus disease named COVID-19 is caused by the virus reported in 2019 first identified in China. The cases of this disease have increased and as of June 1st, 2020 there are more than 216 countries affected. Pharmacological treatments have been proposed based on the resemblance of the HIV virus. With regard to prevention there is no vaccine, thus, we proposed to explore the spike protein due to its presence on the viral surface, and it also contains the putative viral entry receptor as well as the fusion peptide (important in the genome release). In this work we have employed In Silico techniques such as immunoinformatics tools which permit the identification of potential immunogenic regions on the viral surface (spike glycoprotein). From these analyses, we identified four epitopes E332-370, E627-651, E440-464 and E694-715 that accomplish essential features such as promiscuity, conservation grade, exposure and universality, and they also form stable complexes with MHCII molecule. We suggest that these epitopes could generate a specific immune response, and thus, they could be used for future applications such as the design of new epitope vaccines against the SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

In silico and in vivo studies of gp120-HIV-derived peptides in complex with G4-PAMAM dendrimers.

Novel synthetic vaccines as immunotherapy approaches for HIV are interesting strategies that imply big challenges as they increase the poor immunogenic properties of peptide epitopes and their structural damage from the physiological environment. In this work, we used fourth-generation polyamidoamine dendrimers (G4-PAMAM) to increase the immunoglobulin responses (in vivo) induced by two peptide epitopes (pPGT122: DIIGDIRQAH and pVRC03: DGGANNTSNETFR), both recognized by broadly neutralizing antibodies (bNAb) on gp120-HIV type 1. pPGT122 and pVRC03 were identified on the gp120 surface via recognition by bNAb by using X-ray diffraction-derived structures obtained from the Protein Data Bank. pPGT122 and pVRC03 were coupled to the G4-PAMAM molecule by ligand diffusion using molecular dynamics (LDMDS) simulations and their energetic values were calculated by using the MMGBSA approach. Additionally, docking and MD simulations showed the affinity of pPGT122 and pVRC03 for MHC-I/II. G4-PAMAM-peptide complexes were chemically characterized through MALDI-TOF-MS, LC-ESI-QTOF-MS, atomic force microscopy (AFM) and 1H NMR spectroscopy. Then, the G4-PAMAM-peptide complexes were assayed in vivo by intranasal administration in female BALB/cJ mouse groups, showing that both peptides were immunogenic systemically and in the mucous membrane (in nasal and vaginal washes) via increase in IgG and IgA, respectively. This demonstrated that G4-PAMAM can be used as a nanocarrier for immunogenic peptides.

Principal Physicochemical Methods Used to Characterize Dendrimer Molecule Complexes Used as Genetic Therapy Agents, Nanovaccines or Drug Carriers.

Nanomedicine is the application of nanotechnology to medicine. This field is related to the study of nanodevices and nanomaterials applied to various medical uses, such as in improving the pharmacological properties of different molecules. Dendrimers are synthetic nanoparticles whose physicochemical properties vary according to their chemical structure. These molecules have been extensively investigated as drug nanocarriers to improve drug solubility and as sustained-release systems. New therapies such as gene therapy and the development of nanovaccines can be improved by the use of dendrimers. The biophysical and physicochemical characterization of nucleic acid/peptide-dendrimer complexes is crucial to identify their functional properties prior to biological evaluation. In that sense, it is necessary to first identify whether the peptide-dendrimer or nucleic aciddendrimer complexes can be formed and whether the complex can dissociate under the appropriate conditions at the target cells. In addition, biophysical and physicochemical characterization is required to determine how long the complexes remain stable, what proportion of peptide or nucleic acid is required to form the complex or saturate the dendrimer, and the size of the complex formed. In this review, we present the latest information on characterization systems for dendrimer-nucleic acid, dendrimer-peptide and dendrimer-drug complexes with several biotechnological and pharmacological applications.

Predicted 3D Model of the Rabies Virus Glycoprotein Trimer.

The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained.

Synthesis and theoretical calculations of 5-aminosalicylic acid derivatives as potential analgesic agents.

5-Aminosalicylic acid is one of the drugs most commonly used for inflammatory bowel disease treatment, although its use is limited due to side effects. The aim of this work was to synthesize four 5-ASA derivatives (1-4) and analyze their pharmacological effects. The compound structures were elucidated by spectral (IR and 1H and 13C-NMR) analysis, and their analgesic effects and lethal doses 50 (LD50) were evaluated in the mouse model. In addition, their Log Ps and affinities for both cyclooxygenase enzymes (COX I and COX II) were evaluated through theoretical calculations. All compounds showed analgesic activities from 0.1 mg/Kg to 16 mg/Kg in the mouse model. The imides showed more affinity by COX enzymes and their Log Ps were the highest. The docking calculations showed that all compounds have good affinities for COX I and COX II ( identical with 1 microM), making pi-pi, van der Waals interactions and hydrogen bonds. The toxicities of all compounds were low, judging by the LD50. Finally, the docking analysis show that the compounds act on COX enzymes and their analgesic effects could be mediated in part by the inhibition of these enzymes.