Multivalent hydrogen-bonded architectures directed by self-complementarity between [Cu(2,2'-biimidazole)] and malonate building blocks.

The synthesis and structural characterization of four novel supramolecular hydrogen-bonded arrangements based on self-assembly from molecular `[Cu(2,2'-biimidazole)]' modules and malonate anions are presented, namely, tetrakis(2,2'-biimidazole)di-µ-chlorido-dimalonatotricopper(II) pentahydrate, [Cu3(C3H2O4)2Cl2(C6H6N4)4]·5H2O or [Cu(H2biim)2(µ-Cl)Cu0.5(mal)]2·5H2O, aqua(2,2'-biimidazole)malonatocopper(II) dihydrate, [Cu(C3H2O4)(C6H6N4)(H2O)]·2H2O or [Cu(H2biim)(mal)(H2O)]·2H2O, bis[aquabis(2,2'-biimidazole)copper(II)] dimalonatodiperchloratocopper(II) 2.2-hydrate, [Cu(C6H6N4)2(H2O)]2[Cu(C3H2O4)(ClO4)2]·2.2H2O or [Cu(H2biim)2(H2O)]2[Cu(mal)2(ClO4)2]·2.2H2O, and bis(2,2'-biimidazole)copper(II) bis[bis(2,2'-biimidazole)(2-carboxyacetato)malonatocopper(II)] tridecahydrate, [Cu(C6H6N4)2][Cu(C3H2O4)(C3H3O4)(C6H6N4)2]·13H2O or [Cu(H2biim)2][Cu(H2biim)2(Hmal)(mal)]2·13H2O. These assemblies are characterized by self-complementary donor-acceptor molecular interactions, demonstrating a recurrent and distinctive pattern of hydrogen-bonding preferences among the carboxylate, carboxylic acid and N-H groups of the coordinated 2,2'-biimidazole and malonate ligands. Additionally, coordination of the carboxylate group with the metallic centre helps sustain remarkable supramolecular assemblies, such as layers, helices, double helix columns or 3D channeled architectures, including mixed-metal complexes, into a single structure.

L-Citrullinato-Bipyridine and L-Citrullinato-Phenanthroline Mixed Copper Complexes: Synthesis, Characterization and Potential Anticancer Activity.

Citrulline (C6H13N3O3) is an amino acid found in the body as a zwitterion. This means its carboxylic and amine groups can act as Lewis donors to chelate metal cations. In addition, citrulline possesses a terminal ureido group on its aliphatic chain, which also appears to coordinate. Here, two new mixed complexes of citrulline were made with 1,10-phenanthroline and 2,2'-bipyridine. These compounds, once dissolved in water, gave aquo-complexes that were subject to DFT studies and in vitro toxicity studies on cancer cell lines (HeLa, MDA-MB-231, HCT 15, and MCF7) showed promising results. Docking studies with DNA were also conducted, indicating potential anticancer properties.

ω-Phonetoxins inhibit voltage-gated calcium CaV2.2 ion channel splice isoforms of dorsal root ganglia.

Cell-specific alternative splicing of Cacna1b pre-mRNA generates functionally distinct voltage-gated CaV2.2 channels. CaV2.2 channels mediate the release of glutamate from nociceptor termini in the dorsal horn spinal cord and they are implicated in chronic pain. One alternatively spliced exon in Cacna1b, e37a, is highly expressed in dorsal root ganglia, relative to other regions of the nervous system, and it is particularly important in inflammatory hyperalgesia. Here we studied the effects of two ω-phonetoxins, PnTx3-4 and Phα1ß, derived from the spider Phoneutria nigriventer on CaV2.2 channel isoforms of dorsal root ganglia (CaV2.2 e37a and CaV2.2 e37b). Both PnTx3-4 and Phα1ß are known to have analgesic effects in rodent models of pain and to inhibit CaV2.2 channels. CaV2.2 e37a and CaV2.2 e37b isoforms expressed in a mammalian cell line were inhibited by PnTx3-4 and Phα1ß with similar potency and with similar timecourse, although CaV2.2 e37a currents were slightly, but consistently more sensitive to toxin inhibition compared to CaV2.2 e37b. The inhibitory effects of PnTx3-4 and Phα1ß on CaV2.2-e37a and CaV2.2-e37b channels were voltage-dependent, and both occlude the inhibitory effects of ω-conotoxin GVIA, consistent with a common site of action. The potency of PnTx3-4 and Phα1ß on both major splice isoforms in dorsal root ganglia constribute to understanding the analgesic actions of these ω-phonetoxins.

Evaluation of the Stability of a 1,8-Cineole Nanoemulsion and Its Fumigant Toxicity Effect against the Pests Tetranychus urticae, Rhopalosiphum maidis and Bemisia tabaci.

Pest control is a main concern in agriculture. Indiscriminate application of synthetic pesticides has caused negative impacts leading to the rapid development of resistance in arthropod pests. Plant secondary metabolites have been proposed as a safer alternative to conventional pesticides. Monoterpenoids have reported bioactivities against important pests; however, due to their high volatility, low water solubility and chemical instability, the application of these compounds has been limited. Nanosystems represent a potential vehicle for the broad application of monoterpenoids. In this study, an 1,8-cineole nanoemulsion was prepared by the low energy method of phase inversion, characterization of droplet size distribution and polydispersity index (PDI) was carried out by dynamic light scattering and stability was evaluated by centrifugation and Turbiscan analysis. Fumigant bioactivity was evaluated against Tetranychus urticae, Rhopalosiphum maidis and Bemisia tabaci. A nanoemulsion with oil:surfactant:water ratio of 0.5:1:8.5 had a droplet size of 14.7 nm and PDI of 0.178. Formulation was stable after centrifugation and the Turbiscan analysis showed no particle migration and a delta backscattering of ±1%. Nanoemulsion exhibited around 50% more bioactivity as a fumigant on arthropods when compared to free monoterpenoid. These results suggest that nanoformulations can provide volatile compounds of protection against volatilization, improving their bioactivity.

O1-conotoxin Tx6.7 cloned from the genomic DNA of Conus textile that inhibits calcium currents.

Background: Conotoxins exhibit great potential as neuropharmacology tools and therapeutic candidates due to their high affinity and specificity for ion channels, neurotransmitter receptors or transporters. The traditional methods to discover new conotoxins are peptide purification from the crude venom or gene amplification from the venom duct. Methods: In this study, a novel O1 superfamily conotoxin Tx6.7 was directly cloned from the genomic DNA of Conus textile using primers corresponding to the conserved intronic sequence and 3' UTR elements. The mature peptide of Tx6.7 (DCHERWDWCPASLLGVIYCCEGLICFIAFCI) was synthesized by solid-phase chemical synthesis and confirmed by mass spectrometry. Results: Patch clamp experiments on rat DRG neurons showed that Tx6.7 inhibited peak calcium currents by 59.29 ± 2.34% and peak potassium currents by 22.33 ± 7.81%. In addition, patch clamp on the ion channel subtypes showed that 10 µM Tx6.7 inhibited 56.61 ± 3.20% of the hCaV1.2 currents, 24.67 ± 0.91% of the hCaV2.2 currents and 7.30 ± 3.38% of the hNaV1.8 currents. Tx6.7 had no significant toxicity to ND7/23 cells and increased the pain threshold from 0.5 to 4 hours in the mouse hot plate assay. Conclusion: Our results suggested that direct cloning of conotoxin sequences from the genomic DNA of cone snails would be an alternative approach to obtaining novel conotoxins. Tx6.7 could be used as a probe tool for ion channel research or a therapeutic candidate for novel drug development.

Development of Copper Complexes with Diimines and Dipicolinate as Anticancer Cytotoxic Agents.

Coordination complexes may act as anticancer agents. Among others, the formation of the complex may facilitate the ligand uptake by the cell. Searching for new copper compounds with cytotoxic activity, the complex Cu-dipicolinate was studied as a neutral scaffold to form ternary complexes with diimines. A series of [Cu(dipicolinate)(diimine)] complexes (where diimine: Phenanthroline, phen, 5-NO2-phenanthroline, 4-methyl-phenanthroline, neocuproine, 3,4,7,8-tetramethyl-phenanthroline, tmp, bathophenanthroline, bipyridine, dimethyl-bipyridine, as well as the ligand 2,2-dipyridil-amine, bam) were synthesized and characterized both in the solid state, including a new crystal structure of [Cu2(dipicolinate)2(tmp)2]·7H2O. Their chemistry in aqueous solution was explored by UV/vis spectroscopy, conductivity, cyclic voltammetry, and electron paramagnetic resonance studies. Their DNA binding was analyzed by electronic spectroscopy (determining Kb values), circular dichroism, and viscosity methods. The cytotoxicity of the complexes was assessed on human cancer cell lines MDA-MB-231, MCF-7 (breast, the first triple negative), A549 (lung epithelial) and A2780cis (ovarian, Cisplatin-resistant), and non-tumor cell lines MRC-5 (lung) and MCF-10A (breast). The major species are ternary, in solution and solid state. Complexes are highly cytotoxic as compared to Cisplatin. Complexes containing bam and phen are interesting candidates to study their in vivo activity in triple-negative breast cancer treatment.

A Preclinical Model for Parkinson's Disease Based on Transcriptional Gene Activation via KEAP1/NRF2 to Develop New Antioxidant Therapies.

Investigations of the effect of antioxidants on idiopathic Parkinson's disease have been unsuccessful because the preclinical models used to propose these clinical studies do not accurately represent the neurodegenerative process of the disease. Treatment with certain exogenous neurotoxins induces massive and extremely rapid degeneration; for example, MPTP causes severe Parkinsonism in just three days, while the degenerative process of idiopathic Parkinson´s disease proceeds over many years. The endogenous neurotoxin aminochrome seems to be a good alternative target since it is formed in the nigrostriatal system neurons where the degenerative process occurs. Aminochrome induces all the mechanisms reported to be involved in the degenerative processes of idiopathic Parkinson's disease. The presence of neuromelanin-containing dopaminergic neurons in the postmortem brain of healthy elderly people suggests that neuromelanin synthesis is a normal and harmless process despite the fact that it requires oxidation of dopamine to three ortho-quinones that are potentially toxic, especially aminochrome. The apparent contradiction that neuromelanin synthesis is harmless, despite its formation via neurotoxic ortho-quinones, can be explained by the protective roles of DT-diaphorase and glutathione transferase GSTM2-2 as well as the neuroprotective role of astrocytes secreting exosomes loaded with GSTM2-2. Increasing the expression of DT-diaphorase and GSTM2-2 may be a therapeutic goal to prevent the degeneration of new neuromelanin-containing dopaminergic neurons. Several phytochemicals that induce DT-diaphorase have been discovered and, therefore, an interesting question is whether these phytochemical KEAP1/NRF2 activators can inhibit or decrease aminochrome-induced neurotoxicity.

O1-conotoxin Tx6. 7 cloned from the genomic DNA of Conus textile that inhibits calcium currents

Background: Conotoxins exhibit great potential as neuropharmacology tools and therapeutic candidates due to their high affinity and specificity for ion channels, neurotransmitter receptors or transporters. The traditional methods to discover new conotoxins are peptide purification from the crude venom or gene amplification from the venom duct. Methods: In this study, a novel O1 superfamily conotoxin Tx6.7 was directly cloned from the genomic DNA of Conus textile using primers corresponding to the conserved intronic sequence and 3' UTR elements. The mature peptide of Tx6.7 (DCHERWDW CPASLLGVIYCCEGLICFIAFCI) was synthesized by solid-phase chemical synthesis and confirmed by mass spectrometry. Results: Patch clamp experiments on rat DRG neurons showed that Tx6.7 inhibited peak calcium currents by 59.29 ± 2.34% and peak potassium currents by 22.33 ± 7.81%. In addition, patch clamp on the ion channel subtypes showed that 10 µM Tx6.7 inhibited 56.61 ± 3.20% of the hCaV1.2 currents, 24.67 ± 0.91% of the hCaV2.2 currents and 7.30 ± 3.38% of the hNaV1.8 currents. Tx6.7 had no significant toxicity to ND7/23 cells and increased the pain threshold from 0.5 to 4 hours in the mouse hot plate assay. Conclusion: Our results suggested that direct cloning of conotoxin sequences from the genomic DNA of cone snails would be an alternative approach to obtaining novel conotoxins. Tx6.7 could be used as a probe tool for ion channel research or a therapeutic candidate for novel drug development.(AU)

Protective effects of Zizyphus oxyphyla on liver and kidney related serum biomarkers in (CCl4) intoxicate rabbits / Efeitos protetores de Zizyphus oxyphyla em biomarcadores de soro relacionados ao fígado e rim em (CCl4) intoxicam rabbtis

The study was aimed to evaluate the therapeutic effects of Zizyphus oxyphyla leaves methanolic (ZOX-LME), on serum liver, kidney and hematology along with other serum parameters in Carbon tetrachloride (CCl4) intoxicated rabbits. Experimental animals were divided into five groups, six rabbits in each. These were: group NC (normal control), group, TC (toxic control) and group ST i.e. silymarine administered group at dose rate (50) mg/kg body weight (BW). Group ET1 and group ET2 treated with (ZOX-LME) at dose 200 mg/kg BW and 400 mg/kg BW. CCl4 administration caused significant (P> 0.05) impairment in serum liver enzymes, blood factors and other serum indices. Treatment with (ZOX-LME) significantly (P<0.05) reduced and normalized the levels of serum alanine transaminase (ALT) aspartate transaminase (AST) and alkaline phosphatase (ALP) and hematological indices. Also significant (P< 0.05) reduction was observed in creatinine, urea, uric acid, blood urea nitrogen (BUN), and albumin and glucose concentrations. The altered levels of lipid profile and serum electrolytes (Ca, Mg, Cl, Na, K, and P) were significantly (P<0.05) change toward normal levels with (ZOX-LME) feeding. In addition (ZOX-LME) ingestion caused significant improvement in GSH, GST and CAT levels, while reducing the TBARS levels, exhibited antioxidant capacity. Also (ZOX-LME) showed increase inhibition against percent scavenging of 2, 2-diphenile-1-picrylehydrazyle (DPPH) free radical. Significant (P<0.05) normalizing effects were observed with high dose 400 mg/kg BW of (ZOX-LME and were equivalent to silymarine administered groups. The histological study of liver supported the hepatoprotective and renal curative activity of (ZOX-LME).(AU)

O estudo teve como objetivo avaliar os efeitos terapêuticos das folhas metanólicas de Zizyphus oxyphyla (ZOX-LME) no fígado, rim e hematologia séricos, juntamente com outros parâmetros séricos em coelhos intoxicados com tetracloreto de carbono (CCl4). Os animais experimentais foram divididos em cinco grupos, seis coelhos em cada. Estes foram: grupo NC (controle normal), grupo TC (controle tóxico) e grupo ST, isto é, grupo administrado com silimarina na taxa de dose (50) mg / kg de peso corporal (PC). Grupo ET1 e grupo ET2 tratado com (ZOX-LME) na dose de 200 mg / kg de peso corporal e 400 mg / kg de peso corporal. A administração de CCl4 causou prejuízo significativo (P > 0,05) nas enzimas hepáticas séricas, fatores sanguíneos e outros índices séricos. O tratamento com (ZOX-LME) reduziu significativamente (P < 0,05) e normalizou os níveis de alanina transaminase (ALT), aspartato transaminase (AST) e fosfatase alcalina (ALP) e os índices hematológicos. Também foi observada redução significativa (P < 0,05) nas concentrações de creatinina, ureia, ácido úrico, nitrogênio ureico no sangue (BUN), albumina e glicose. Os níveis alterados de perfil lipídico e eletrólitos séricos (Ca, Mg, Cl, Na, K e P) foram significativamente (P < 0,05) mudando em direção aos níveis normais com a alimentação (ZOX-LME). Além disso, a ingestão de (ZOX-LME) causou melhora significativa nos níveis de GSH, GST e CAT, enquanto reduzia os níveis de TBARS, exibindo capacidade antioxidante. Também (ZOX-LME) mostrou inibição aumentada contra a eliminação percentual do radical livre 2, 2-difenila-1-picrilehidrazila (DPPH). Efeitos de normalização significativos (P < 0,05) foram observados com altas doses de 400 mg / kg de peso corporal de (ZOX-LME) e foram equivalentes aos grupos administrados com silimarina. O estudo histológico do fígado confirmou a atividade hepatoprotetora e curativa renal de (ZOX-LME).(AU)

Protective effects of Zizyphus oxyphyla on liver and kidney related serum biomarkers in (CCl4) intoxicate rabbits / Efeitos protetores de Zizyphus oxyphyla em biomarcadores de soro relacionados ao fígado e rim em (CCl4) intoxicam rabbtis

The study was aimed to evaluate the therapeutic effects of Zizyphus oxyphyla leaves methanolic (ZOX-LME), on serum liver, kidney and hematology along with other serum parameters in Carbon tetrachloride (CCl4) intoxicated rabbits. Experimental animals were divided into five groups, six rabbits in each. These were: group NC (normal control), group, TC (toxic control) and group ST i.e. silymarine administered group at dose rate (50) mg/kg body weight (BW). Group ET1 and group ET2 treated with (ZOX-LME) at dose 200 mg/kg BW and 400 mg/kg BW. CCl4 administration caused significant (P> 0.05) impairment in serum liver enzymes, blood factors and other serum indices. Treatment with (ZOX-LME) significantly (P<0.05) reduced and normalized the levels of serum alanine transaminase (ALT) aspartate transaminase (AST) and alkaline phosphatase (ALP) and hematological indices. Also significant (P< 0.05) reduction was observed in creatinine, urea, uric acid, blood urea nitrogen (BUN), and albumin and glucose concentrations. The altered levels of lipid profile and serum electrolytes (Ca, Mg, Cl, Na, K, and P) were significantly (P<0.05) change toward normal levels with (ZOX-LME) feeding. In addition (ZOX-LME) ingestion caused significant improvement in GSH, GST and CAT levels, while reducing the TBARS levels, exhibited antioxidant capacity. Also (ZOX-LME) showed increase inhibition against percent scavenging of 2, 2-diphenile-1-picrylehydrazyle (DPPH) free radical. Significant (P<0.05) normalizing effects were observed with high dose 400 mg/kg BW of (ZOX-LME and were equivalent to silymarine administered groups. The histological study of liver supported the hepatoprotective and renal curative activity of (ZOX-LME).

O estudo teve como objetivo avaliar os efeitos terapêuticos das folhas metanólicas de Zizyphus oxyphyla (ZOX-LME) no fígado, rim e hematologia séricos, juntamente com outros parâmetros séricos em coelhos intoxicados com tetracloreto de carbono (CCl4). Os animais experimentais foram divididos em cinco grupos, seis coelhos em cada. Estes foram: grupo NC (controle normal), grupo TC (controle tóxico) e grupo ST, isto é, grupo administrado com silimarina na taxa de dose (50) mg / kg de peso corporal (PC). Grupo ET1 e grupo ET2 tratado com (ZOX-LME) na dose de 200 mg / kg de peso corporal e 400 mg / kg de peso corporal. A administração de CCl4 causou prejuízo significativo (P > 0,05) nas enzimas hepáticas séricas, fatores sanguíneos e outros índices séricos. O tratamento com (ZOX-LME) reduziu significativamente (P < 0,05) e normalizou os níveis de alanina transaminase (ALT), aspartato transaminase (AST) e fosfatase alcalina (ALP) e os índices hematológicos. Também foi observada redução significativa (P < 0,05) nas concentrações de creatinina, ureia, ácido úrico, nitrogênio ureico no sangue (BUN), albumina e glicose. Os níveis alterados de perfil lipídico e eletrólitos séricos (Ca, Mg, Cl, Na, K e P) foram significativamente (P < 0,05) mudando em direção aos níveis normais com a alimentação (ZOX-LME). Além disso, a ingestão de (ZOX-LME) causou melhora significativa nos níveis de GSH, GST e CAT, enquanto reduzia os níveis de TBARS, exibindo capacidade antioxidante. Também (ZOX-LME) mostrou inibição aumentada contra a eliminação percentual do radical livre 2, 2-difenila-1-picrilehidrazila (DPPH). Efeitos de normalização significativos (P < 0,05) foram observados com altas doses de 400 mg / kg de peso corporal de (ZOX-LME) e foram equivalentes aos grupos administrados com silimarina. O estudo histológico do fígado confirmou a atividade hepatoprotetora e curativa renal de (ZOX-LME).

Carotenoids from Haloarchaea: Extraction, Fractionation, and Characterization.

Carotenoids are bioactive molecules known to promote human health. Many extreme halophilic archaea synthesize carotenoids, mainly represented by C50 bacterioruberin (BR) and its derivatives. BR has a potent antioxidant capacity, even higher than that of ß-carotene, thus, there is an increasing interest to advance the study of its biological properties as well as to extend its current applications. Here, we describe a procedure to extract and characterize carotenoids (enriched in BR) from haloarchaea using a "hyperpigmented" genetically modified strain of Haloferax volcanii.

Favipiravir and/or nitazoxanide: a randomized, double-blind, 2×2 design, placebo-controlled trial of early therapy in COVID-19 in health workers, their household members, and patients treated at IMSS (FANTAZE).

BACKGROUND: The 2020 pandemic of SARS-CoV-2 causing COVID-19 disease is an unprecedented global emergency. COVID-19 appears to be a disease with an early phase where the virus replicates, coinciding with the first presentation of symptoms, followed by a later 'inflammatory' phase which results in severe disease in some individuals. It is known from other rapidly progressive infections such as sepsis and influenza that early treatment with antimicrobials is associated with a better outcome. The hypothesis is that this holds for COVID-19 and that early antiviral treatment may prevent progression to the later phase of the disease. METHODS: Trial design: Phase IIA randomised, double-blind, 2 × 2 design, placebo-controlled, interventional trial. RANDOMISATION: Participants will be randomised 1:1 by stratification, with the following factors: gender, obesity, symptomatic or asymptomatic, current smoking status presence or absence of comorbidity, and if the participant has or has not been vaccinated. BLINDING: Participants and investigators will both be blinded to treatment allocation (double-blind). DISCUSSION: We propose to conduct a proof-of-principle placebo-controlled clinical trial of favipiravir plus or minus nitazoxanide in health workers, their household members and patients treated at the Mexican Social Security Institute (IMSS) facilities. Participants with or without symptomatic COVID-19 or who tested positive will be assigned to receive favipiravir plus nitazoxanide or favipiravir plus nitazoxanide placebo. The primary outcome will be the difference in the amount of virus ('viral load') in the upper respiratory tract after 5 days of therapy. Secondary outcomes will include hospitalization, major morbidity and mortality, pharmacokinetics, and impact of antiviral therapy on viral genetic mutation rate. If favipiravir with nitazoxanide demonstrates important antiviral effects without significant toxicity, there will be a strong case for a larger trial in people at high risk of hospitalization or intensive care admission, for example older patients and/or those with comorbidities and with early disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT04918927 . Registered on June 9, 2021.

Synthesis of a 2-nitroimidazole derivative N-(4-[18F]fluorobenzyl)-2-(2-nitro-1H-imidazol-1-yl)-acetamide ([18 F]FBNA) as PET radiotracer for imaging tumor hypoxia.

BACKGROUND: Tissue hypoxia is a pathological condition characterized by reducing oxygen supply. Hypoxia is a hallmark of tumor environment and is commonly observed in many solid tumors. Non-invasive imaging techniques like positron emission tomography (PET) are at the forefront of detecting and monitoring tissue hypoxia changes in vivo. RESULTS: We have developed a novel 18F-labeled radiotracer for hypoxia PET imaging based on cytotoxic agent benznidazole. Radiotracer N-(4-[18F]fluorobenzyl)-2-(2-nitro-1H-imidazol-1-yl)acetamide ([18F]FBNA) was synthesized through acylation chemistry with readily available 4-[18F]fluorobenzyl amine. Radiotracer [18F]FBNA was obtained in good radiochemical yields (47.4 ± 5.3%) and high radiochemical purity (> 95%). The total synthesis time was 100 min, including HPLC purification and the molar activity was greater than 40 GBq/µmol. Radiotracer [18F]FBNA was stable in saline and mouse serum for 6 h. [18F]FBNA partition coefficient (logP = 1.05) was found to be more lipophilic than [18F]EF-5 (logP = 0.75), [18F]FMISO (logP = 0.4) and [18F]FAZA (logP = - 0.4). In vitro studies showed that [18F]FBNA accumulates in gastric cancer cell lines AGS and MKN45 under hypoxic conditions. CONCLUSIONS: Hence, [18F]FBNA represents a novel and easy-to-prepare PET radioligand for imaging hypoxia.

M2-2 gene as a new alternative molecular marker for phylogenetic, phylodynamic, and evolutionary studies of hRSV.

The human Respiratory Syncytial Virus (hRSV) is the main causative agent of acute respiratory infections (ARI), such as pneumonia and bronchiolitis. One of the factors that lead to success in viral replication is the interaction of the M2-2 protein with the ribosomal complex. This interaction is responsible for the phase change of viral activity, acting as an inhibitor or inducer of viral replication, according to the concentration of mRNA. Based on the importance of M2-2 gene and protein have to viral physiology, we performed here evaluations of genetic diversity, phylogenetic reconstructions, phylodynamics, and selection test. Our results suggested an alternative way of classifying this virus in clades A and B, based on a new phylogenetic marker, the M2-2 gene. Therefore, our study is the first one to investigate the dynamics of the evolutionary diversification process of hRSV from the perspective of the M2-2 viral gene. In our study was also identified that the M2-2 gene is under the effect of purifying selection originated by population genetic bottlenecks. Therefore, the M2-2 gene demonstrated an interesting potential to be applied in evolutionary studies involving hRSV, recovering phylogenetic signals and traits of natural selection under the evolution of this virus.

Enhanced antitumor effect of L-buthionine sulfoximine or ionizing radiation by copper complexes with 2,2´-biquinoline and sulfonamides on A549 2D and 3D lung cancer cell models.

Two ternary copper(II) complexes with 2,2'-biquinoline (BQ) and with sulfonamides: sulfamethazine (SMT) or sulfaquinoxaline (SDQ) whose formulae are Cu(SMT)(BQ)Cl and Cu(SDQ)(BQ)Cl·CH3OH, in what follows SMTCu and SDQCu, respectively, induced oxidative stress by increasing ROS level from 1.0 µM and the reduction potential of the couple GSSG/GSH2. The co-treatment with L-buthionine sulfoximine (BSO), which inhibits the production of GSH, enhanced the effect of copper complexes on tumor cell viability and on oxidative damage. Both complexes generated DNA strand breaks given by-at least partially-the oxidation of pyrimidine bases, which caused the arrest of the cell cycle in the G2/M phase. These phenomena triggered processes of apoptosis proven by activation of caspase 3 and externalization of phosphatidylserine and loss of cell integrity from 1.0 µM. The combination with BSO induced a marked increase in the apoptotic population. On the other hand, an improved cell proliferation effect was observed when combining SDQCu with a radiation dose of 2 Gy from 1.0 µM or with 6 Gy from 1.5 µM. Finally, studies in multicellular spheroids demonstrated that even though copper(II) complexes did not inhibit cell invasion in collagen gels up to 48 h of treatment at the higher concentrations, multicellular resistance outperformed several drugs currently used in cancer treatment. Overall, our results reveal an antitumor effect of both complexes in monolayer and multicellular spheroids and an improvement with the addition of BSO. However, only SDQCu was the best adjuvant of ionizing radiation treatment.

Astrocytes protect dopaminergic neurons against aminochrome neurotoxicity.

Astrocytes protect neurons by modulating neuronal function and survival. Astrocytes support neurons in several ways. They provide energy through the astrocyte-neuron lactate shuttle, protect neurons from excitotoxicity, and internalize neuronal lipid droplets to degrade fatty acids for neuronal metabolic and synaptic support, as well as by their high capacity for glutamate uptake and the conversion of glutamate to glutamine. A recent reported astrocyte system for protection of dopamine neurons against the neurotoxic products of dopamine, such as aminochrome and other o-quinones, were generated under neuromelanin synthesis by oxidizing dopamine catechol structure. Astrocytes secrete glutathione transferase M2-2 through exosomes that transport this enzyme into dopaminergic neurons to protect these neurons against aminochrome neurotoxicity. The role of this new astrocyte protective mechanism in Parkinson´s disease is discussed.

Evaluation of toxicological aspects of three new benzoxazole compounds with sunscreen photophysical properties using in silico and in vitro methods.

Sunscreening chemicals protect against damage caused by sunlight most absorbing UVA or UVB radiations. In this sense, 2-(2'-hydroxyphenyl)benzoxazole derivatives with amino substituents in the 4' and 5' positions have an outstandingly high Sun Protection Factor and adequate photostability, but their toxicity is not yet known. This study aimed to evaluate the toxicity of three synthetic 2-(2'-hydroxyphenyl)benzoxazole derivatives for their possible application as sunscreens. In silico tools were used in order to assess potential risks regarding mutagenic, carcinogenic, and skin sensitizing potential. Bioassays were performed in L929 cells to assess cytotoxicity in MTT assay and genotoxic activities in the Comet assay and micronucleus test. Also, the Salmonella/microsome assay was performed to evaluate gene mutations. The in silico predictions indicate a low risk of mutagenicity and carcinogenicity of the compounds while the skin sensitizing potential was low or inconclusive. The 2-(4'-amino-2'-hydroxyphenyl)benzoxazol compound was the most cytotoxic and genotoxic among the compounds evaluated in L929 cells, but none induced mutations in the Salmonella/microsome assay. The amino substituted at the 4' position of the phenyl ring appears to have greater toxicological risks than substituents at the 5' position of 2-(phenyl)benzoxazole. The findings warrant further studies of these compounds in cosmetic formulations.

A study on 2-(2'-hydroxyphenyl) benzoxazoles derivatives as potential organic UV filters, Part I

Abstract Damage resulting from the incidence of ultraviolet (UV) radiation on the skin is common nowadays, with UVB (290-320 nm) and UVA (320-400 nm) radiation responsible for photoaging, sunburn and carcinogenesis. For this reason, sunscreens represent products of growing interest to prevent such damage. However, there are few organic filters marketed worldwide with photostability and effectiveness at wavelengths greater than 340 nm (long UVA), which justifies the exploration for new compounds. In this work, we determined the photostability and sun protection factor (SPF) of three 2-(2'-hydroxyphenyl)benzoxazole derivative dyes in order to develop new organic UV filters. UV-vis spectrophotometry has high level of reproducibility when compared with in vivo human clinical methods. Solubility determinations were performed in different solvents. The compounds absorbed UVA and UVB radiation, with maximum absorption wavelengths ranging from 336 to 374 nm. Photostability was evaluated using a solar simulator (3 J.m2.s-1 UVA radiation) for a maximum of 3 h. The 2-(amino-2'-hydroxyphenyl) benzoxazoles showed higher photostability than the acetylated derivative under the evaluated conditions. The three benzoxazoles presented SPF values of around 40 and preliminary results indicate that they show suitable properties to act as good chemical filters in photoprotective formulations.

Validation of a simple liquid chromatography coupled to tandem mass spectrometry method for the simultaneous determination of tacrolimus, sirolimus, everolimus and cyclosporin A in dried matrix on paper discs.

INTRODUCTION: Due to its high specificity and sensitivity, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is the gold standard method for immunosuppressant quantification in therapeutic drug monitoring. In this context, dried blood spots (DBS) have become a promising strategy as a sample collection procedure. Although the advantages of DBS over venipuncture are well known, this approach has limitations that strongly influence the acceptance of analytical results. Among them, the most important is hematocrit (Ht). The easiest way of overcoming this problem is by analyzing complete spots. In this strategy, called dried matrix on paper discs (DMPD), blood is volumetrically applied on pre-punched discs. OBJECTIVES: To validate an LC-MS/MS method for the quantification of tacrolimus, sirolimus, everolimus and cyclosporin A using DMPD. METHODS: The procedure was validated according to international guidelines using a commercial kit. The following performance parameters were evaluated: selectivity, carryover, linearity, accuracy, precision, lower limit of quantitation, relative recovery, commutability and stability. In addition, a method comparison study was performed to evaluate the clinical influence of Ht on the results. RESULTS: All performance parameters were within acceptance criteria and, hence, it was determined that the validated method is fit for the intended purpose. Likewise, calculated bias values on medical decision levels showed that there was no clinical influence of Ht on the results. CONCLUSION: Unlike other similar methodologies that have been published, here, a simple method has been fully validated. This is the first LC-MS/MS methodology adapting a commercial kit to use DMPD as a sampling strategy.