Blocking Activity Research Articles

Synthesis of Ethyl Methyl 4-aryl-1,4-dihydropyridine-3,5-dicarboxylates as Potential Calcium Channel Blockers for Hypertension

Aim: Several new dihydropyridine-based calcium channel blockers have been synthesized and pharmacologically evaluated for the treatment of hypertension Background: Dihydropyridines constitute an important class of calcium channel blockers (CCBs) due to their high potency, wide heterogeneity and tremendous biological usefulness. As a follow-up to our previous studies on 4-aryl-1,4-dihydropyridines as calcium channel blockers for the treatment of hypertension, four new series of methyl ethyl ester substituted 1,4-dihydropyridines are reported. Objectives: The aim of the work was to study the effects of unsymmetrical ester substitutions on calcium channel blocking activity of dihydropyridines (DHPs) while retaining the aminoalkoxy side chain at various positions of the 4-aryl ring. The type and location of the substituents on the 4-aryl ring have been extensively explored to study the structure-activity relationship (SAR) in this series of dihydropyridines as calcium channel blockers. Methodology: The target DHPs were synthesized using modified Hantzsch condensation and further derivatization. The compounds were screened for their inhibitory potential against L-type calcium channels at a single concentration of 10 μM on NG108-15 cells (Neuroblastoma X Glioma). The most potent DHP 12 was also tested for its vasodilatory activity using rat thoracic aortic rings precontracted with KCl (30 mM) and in vivo antihypertensive activity in rats using the tail-cuff method. Results: The newly synthesized DHPs displayed diversified calcium channel blocking activity with compounds 1e, 1h, 2d, 2f, 2h, 6, 9, 11, 12 and 14, producing more than 50% inhibition of veratridine response. 3-imidazolylpropoxy substituted analogue 12 turned out to be the most potent compound of the four series of compounds and produced fairly higher inhibition (78.6%) of veratridine response in comparison to nifedipine (70%) at 10 μM. In addition, compound 12 produced potent vasodilatory and antihypertensive properties. Conclusion: Both location of the side chain and the type of substituent on methyl ethyl ester substituted 4-aryl ring affected the response of dihydropyridine derivatives towards L-type calcium channels.

Synthesis and Evaluation of Some New Pyridines as Possible P-gp Inhibitors with Reduced Calcium Channel Blocking Activity

The 1,4-dihydropyridine derivatives (DHPs) (3a-b and 4a-c) were oxidized with iodine in methanol to produce five new, hitherto unreported pyridine derivatives (5a-b and 6a-c). The “Everted sac method” was used to assess the DHPs and their pyridines for potential p-glycoprotein (P-gp) inhibitory or multidrug resistance reversal action. Domperidone, a P-gp substrate, was examined for intestinal absorption in everted rat jejunal segments in the presence and absence of DHPs (3a-b and 4a-c) and pyridines (5a-b and 6a-c) at doses of 30 μg/mL and 100 μg/mL. The standard was Verapamil, a known P-gp inhibitor (30 μg/mL and 100 μg/mL). The P-gp inhibition of all the tested compounds was higher than Verapamil. The P-gp inhibition of compounds 5b and 6b was the highest. Utilizing isolated rat ileum, the newly synthesized pyridine derivatives calcium channel blocking efficacy was also investigated. The strongest Ca2+ channel-blocking action was seen with compound 5b. It was determined to be equivalent to Nifedipine, the gold standard. Strong P-gp inhibitor compound 6b has little calcium channel-blocking action.

Costimulatory capacity of CD137 mAbs on T cells depends on elaborate CRD structures but not on blocking ligand-receptor binding.

CD137 is mainly a costimulatory receptor of CD8+ T cells. Two representative CD137 antibodies, utomilumab, and urelumab, show different costimulatory capacities in clinical trials. Balancing the antitumor effect and systemic toxicity of T cells activated by CD137 signaling is a challenge that requires clinical consideration. In this study, a panel of specific anti-human CD137 monoclonal antibodies (mAbs) were prepared and their affinities, isotypes, CD137-CRD (cysteine-rich domain) binding regions, cross-reactivity to mouse and rhesus CD137, inhibition of ligand-receptor binding and costimulatory activities were analyzed. The results showed that anti-human CD137 mAbs had high cross-reactivity with rhesus CD137. MAbs fell into three clusters according to their different binding regions of the CD137 extracellular domain. They bound to CRDI+CRDII, CRDIII or CRDIV+STP. CRDIII-binding mAbs had the strongest blocking activity. Highly costimulatory CD137 mAbs showed stronger abilities to promote CD8+ T-cell proliferation. However, the costimulatory capacity of mAbs on T cells was not closely related to their ability to block CD137L-CD137 binding and may be controlled by more elaborate CRD conformational structures. This study provides additional information for the development of next-generation CD137 mAbs to meet clinical needs.

Website blocking in the European Union: Network interference from the perspective of Open Internet

AbstractBy establishing an infrastructure for monitoring and blocking networks in accordance with European Union (EU) law on preventive measures against the spread of information, EU member states have also made it easier to block websites and services and monitor information. While relevant studies have documented Internet censorship in non‐European countries, as well as the use of such infrastructures for political reasons, this study examines network interference practices such as website blocking against the backdrop of an almost complete lack of EU‐related research. Specifically, it performs and demonstrates an analysis for the total of 27 EU countries based on three different sources. They include first, tens of millions of historical network measurements collected in 2020 by Open Observatory of Network Interference volunteers from around the world; second, the publicly available blocking lists used by EU member states; and third, the reports issued by network regulators in each country from May 2020 to April 2021. Our results show that authorities issue multiple types of blocklists. Internet Service Providers limit access to different types and categories of websites and services. Such resources are sometimes blocked for unknown reasons and not included in any of the publicly available blocklists. The study concludes with the hurdles related to network measurements and the nontransparency from regulators regarding specifying website addresses in blocking activities.

A reference architecture for the American Multi-Modal Energy System enterprise

The American Multimodal Energy System (AMES) is a system-of-systems comprised of four separate but interdependent infrastructure enterprises: the electric grid, the natural gas enterprise, the oil enterprise, and the coal enterprise. Their interdependence creates the need to better understand the underlying architecture in order to move towards a more sustainable, resilient and accessible energy system. Collectively, these requirements necessitate a sustainable energy transition that constitute a change in the AMES instantiated architecture; although it leaves its reference architecture largely unchanged. Consequently, from a model-based systems engineering perspective, identifying the underlying enterprise model’s reference architecture becomes a high priority. This paper defines a reference architecture for the AMES and its four component energy enterprises in a single SysML model. The architecture includes (allocated) block definition and activity diagrams for each enterprise. The reference architecture was developed from the S&P Global Platts (GIS) Map Data Pro data set and the EIA Annual Energy Outlook dataset. This reference architecture serves as the foundation from which to accurately and consistently create mathematical and informatic digital twins of the AMES.

Mobile Cardiac Telemetry Use to Predict Adverse Pregnancy Outcomes in Patients With Congenital Heart Disease

BackgroundPatients with congenital heart disease (CHD) have a higher incidence of arrhythmias during pregnancy, yet the utility of mobile cardiac telemetry (MCT) to predict adverse outcomes is unknown. ObjectivesThe purpose of this study is to determine whether arrhythmias on screening MCT correlate with adverse pregnancy outcomes. MethodsPatients with CHD prospectively enrolled in the Standardized Outcomes in Reproductive Cardiovascular Care initiative underwent 24-hour MCT (within 18 months prior to pregnancy). Positive findings on MCT were defined as episodes of bradyarrhythmia, symptomatic atrioventricular block, ectopic atrial or ventricular activity, and supraventricular or ventricular tachycardia. Clinically significant arrhythmia events (CSAEs) were those requiring medical or device intervention or an emergency room visit. Clinical events during the antepartum, intrapartum, and postpartum periods were compared using Fisher’s exact test. Analyses were performed using Stata version 16. ResultsIn 141 pregnancies in 118 patients with CHD, MCT detected positive findings in 17%. Adverse cardiac outcomes occurred in 11% of pregnancies, of which CSAE occurred in 3.5%. Positive MCT was significantly associated with subsequent CSAE (21% vs 0%, P < 0.001) and cumulative adverse maternal cardiac outcomes (33% vs 7%, P = 0.001) but did not correlate with obstetric (46% vs 41%, P = 0.660) or neonatal outcomes (33% vs 31%, P = 0.810). Of the patients with CSAE, 75% had ≥moderate CHD complexity. ConclusionsPatients with CHD had a high rate of positive MCT findings. This was associated with CSAE and adverse maternal cardiac outcomes. Patients with ≥moderate CHD complexity may benefit from screening MCT to improve preconceptual counseling and planning.

A cell-based, SARS-CoV-2 spike protein interaction assay to inform the neutralising capacity of recombinant and patient sera antibodies

IntroductionThe engagement of the SARS-CoV-2 spike protein with ACE2 is a critical step for viral entry to human cells, and, therefore, blocking this interaction is a major determinant of the efficacy of monoclonal antibody therapeutics and vaccine elicited serum antibodies. The emergence of SARS-CoV-2 variants has necessitated the development of adaptable assays that can be applied to assess the effectiveness of antibody-based therapeutics.MethodsThrough the testing of a range of recombinant spike proteins, we have developed a cell-based, ACE2/spike protein interaction assay that characterises monoclonal anti-spike protein antibodies and neutralising antibodies in donor serum. The assay uses high-content imaging to quantify cell-bound spike protein fluorescence.ResultsUsing spike proteins from the original “Wuhan” SARS-CoV-2 strain and the Delta and Omicron variants, we identified differential blocking activity of three monoclonal antibodies directed against the spike receptor-binding domain. Importantly, biological activity in the spike interaction assay translated to efficacy in a SARS-CoV-2 infection assay.DiscussionThe spike protein interaction assay can be used to monitor anti-spike antibodies against the major known SARS-CoV-2 variants and is readily adaptable for quantification of the impact of antibodies against new and emerging SARS-CoV-2 variants.

Blockade-of-Binding Activities toward Envelope-Associated, Type-Specific Epitopes as a Correlative Marker for Dengue Virus-Neutralizing Antibody.

Humans infected with dengue virus (DENV) acquire long-term protection against the infecting serotype, whereas cross-protection against other serotypes is short-lived. Long-term protection induced by low levels of type-specific neutralizing antibodies can be assessed using the virus-neutralizing antibody test. However, this test is laborious and time-consuming. In this study, a blockade-of-binding enzyme-linked immunoassay was developed to assess antibody activity by using a set of neutralizing anti-E monoclonal antibodies and blood samples from dengue virus-infected or -immunized macaques. Diluted blood samples were incubated with plate-bound dengue virus particles before the addition of an enzyme-conjugated antibody specific to the epitope of interest. Based on blocking reference curves constructed using autologous purified antibodies, sample blocking activity was determined as the relative concentration of unconjugated antibody that resulted in the same percent signal reduction. In separate DENV-1-, -2-, -3-, and -4-related sets of samples, moderate to strong correlations of the blocking activity with neutralizing antibody titers were found with the four type-specific antibodies 1F4, 3H5, 8A1, and 5H2, respectively. Significant correlations were observed for single samples taken 1 month after infection as well as samples drawn before and at various time points after infection/immunization. Similar testing using a cross-reactive EDE-1 antibody revealed a moderate correlation between the blocking activity and the neutralizing antibody titer only for the DENV-2-related set. The potential usefulness of the blockade-of-binding activity as a correlative marker of neutralizing antibodies against dengue viruses needs to be validated in humans. IMPORTANCE This study describes a blockade-of-binding assay for the determination of antibodies that recognize a selected set of serotype-specific or group-reactive epitopes in the envelope of dengue virus. By employing blood samples collected from dengue virus-infected or -immunized macaques, moderate to strong correlations of the epitope-blocking activities with the virus-neutralizing antibody titers were observed with serotype-specific blocking activities for each of the four dengue serotypes. This simple, rapid, and less laborious method should be useful for the evaluation of antibody responses to dengue virus infection and may serve as, or be a component of, an in vitro correlate of protection against dengue in the future.

LncRNA read-through regulates the BX-C insulator Fub-1.

hough long non-coding RNAs (lncRNAs) represent a substantial fraction of the Pol II transcripts in multicellular animals, only a few have known functions. Here we report that the blocking activity of the Bithorax complex (BX-C) Fub-1 boundary is segmentally regulated by its own lncRNA. The Fub-1 boundary is located between the Ultrabithorax (Ubx) gene and the bxd/pbx regulatory domain, which is responsible for regulating Ubx expression in parasegment PS6/segment A1. Fub-1 consists of two hypersensitive sites, HS1 and HS2. HS1 is an insulator while HS2 functions primarily as a lncRNA promoter. To activate Ubx expression in PS6/A1 enhancers in the bxd/pbx domain must be able to bypass Fub-1 blocking activity. We show that expression of the Fub-1 lncRNAs in PS6/A1 from the HS2 promoter inactivates Fub-1 insulating activity. Inactivation is due to readthrough as the HS2 promoter must be directed towards HS1 to disrupt blocking.

Humoral immune responses associated with control of SARS-CoV-2 breakthrough infections in a vaccinated US military population.

COVID-19 vaccines have been critical for protection against severe disease following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) but gaps remain in our understanding of the immune responses that contribute to controlling subclinical and mild infections. Vaccinated, active-duty US military service members were enrolled in a non-interventional, minimal-risk, observational study starting in May, 2021. Clinical data, serum, and saliva samples were collected from study participants and were used to characterise the humoral immune responses to vaccination and to assess its impact on clinical and subclinical infections, as well as virologic outcomes of breakthrough infections (BTI) including viral load and infection duration. The majority of VIRAMP participants had received the Pfizer COVID-19 vaccine and by January, 2022, N=149 had a BTI. The median BTI duration (PCR+ days) was 4 days and the interquartile range was 1-8 days. Participants that were nucleocapsid seropositive prior to their BTI had significantly higher levels of binding and functional antibodies to the spike protein, shorter median duration of infections, and lower median peak viral loads compared to seronegative participants. Furthermore, levels of neutralising antibody, ACE2 blocking activity, and spike-specific IgA measured prior to BTI also correlated with the duration of infection. We extended previous findings and demonstrate that a subset of vaccine-induced humoral immune responses, along with nucleocapsid serostatus are associated with control of SARS-CoV-2 breakthrough infections in the upper airways. This work was funded by the DoD Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND) in collaboration with the Defense Health Agency (DHA) COVID-19 funding initiative for the VIRAMP study.

Comparison of infraclavicular block and axillary block activities performed in ultrasonography coexisting in upper extremity surgery

Aims: Infraclavicular and axillary block performed with ultrasound guidance are effective peripheral anesthesia methods applied in upper extremity surgery. We aimed to compare these methods in terms of duration of the block and action, first analgesic requirement and side effects.&#x0D; Methods: This prospective, randomized study was conducted for upper extremity surgery. 100 patients were included to perform infraclavicular block (Group 1, n=51) and axillary block (Group 2, n=49) USG guided. Patients are between 19 and 85 years old. Both groups were premedicated with 0.3 mg/kg midazolam or 0.5-1 μg/kg fentanyl. Both groups were treated with a mixture of local anesthetics in a total volume of 30 mL [7.5 mL 0.5% bupivacaine (Bustesin®, 56.25 mg), 7.5 mL 2% prilocaine (Priloc®, 225 mg) and 5 mL saline] was injected. Block placement time, motor and sensory tests, postoperative 2nd, 4th, 8th, 12th. and analgesic requirement at the 24th hour, Bromage scale, Verbal Rating scale, nausea vomiting, patient satisfaction, and block adequacy data were recorded.&#x0D; Results: In this study, 60% of the participants included were male and 40% were female. The systolic, diastolic and mean arterial pressures were higher in group of axillary blockade than those with blockade of infraclavicular blocks. Radial, median, ulnar and musculocutaneous nerve pin-prick test loss and loss of touch test was more frequent in infraclavicular block patients. According to the Bromage scale, the partial block was seen more frequently in patients who had a close block and a full block infraclavicular block. In patients with the axillary blockade, sedoanalgesia and general anesthesia needs after postoperative intraoperative 20 min and postoperative sedoanalgesia was needed. According to the postoperative Bromage scale; complete and close to the thumb and more frequent in infraclavicular block patients. In Postop VRS, it was observed that the patients with the axillary block group had mild, moderate, and severe pain complaints. Patient satisfaction in the postoperative period was similar in both groups.&#x0D; Conclusion: There is no significant difference between these techniques regarding surgical adequacy and subjective postoperative analgesia and dysesthesia. Complete and near-complete block rates in the infraclavicular block approach are minimally higher than in the axillary block approach.

A recombinant Aspergillus oryzae fungus transmitted from larvae to adults of Anopheles stephensi mosquitoes inhibits malaria parasite oocyst development

The control of malaria parasite transmission from mosquitoes to humans is hampered by decreasing efficacies of insecticides, development of drug resistance against the last-resort antimalarials, and the absence of effective vaccines. Herein, the anti-plasmodial transmission blocking activity of a recombinant Aspergillus oryzae (A. oryzae-R) fungus strain, which is used in human food industry, was investigated in laboratory-reared Anopheles stephensi mosquitoes. The recombinant fungus strain was genetically modified to secrete two anti-plasmodial effector peptides, MP2 (midgut peptide 2) and EPIP (enolase-plasminogen interaction peptide) peptides. The transstadial transmission of the fungus from larvae to adult mosquitoes was confirmed following inoculation of A. oryzae-R in the water trays used for larval rearing. Secretion of the anti-plasmodial effector peptides inside the mosquito midguts inhibited oocyst formation of P. berghei parasites. These results indicate that A. oryzae can be used as a paratransgenesis model carrying effector proteins to inhibit malaria parasite development in An. stephensi. Further studies are needed to determine if this recombinant fungus can be adapted under natural conditions, with a minimal or no impact on the environment, to target mosquito-borne infectious disease agents inside their vectors.

Assessment of the transmission blocking activity of antimalarial compounds by membrane feeding assays using natural Plasmodium falciparum gametocyte isolates from West-Africa.

Antimalarial drugs that can block the transmission of Plasmodium gametocytes to mosquito vectors would be highly beneficial for malaria elimination efforts. Identifying transmission-blocking drugs currently relies on evaluation of their activity against gametocyte-producing laboratory parasite strains and would benefit from a testing pipeline with genetically diverse field isolates. The aims of this study were to develop a pipeline to test drugs against P. falciparum gametocyte field isolates and to evaluate the transmission-blocking activity of a set of novel compounds. Two assays were designed so they could identify both the overall transmission-blocking activity of a number of marketed and experimental drugs by direct membrane feeding assays (DMFA), and then also discriminate between those that are active against the gametocytes (gametocyte killing or sterilizing) or those that block development in the mosquito (sporontocidal). These DMFA assays used venous blood samples from naturally infected Plasmodium falciparum gametocyte carriers and locally reared Anopheles gambiae s.s. mosquitoes. Overall transmission-blocking activity was assessed following a 24 hour incubation of compound with gametocyte infected blood (TB-DMFA). Sporontocidal activity was evaluated following addition of compound directly prior to feeding, without incubation (SPORO-DMFA); Gametocyte viability was retained during 24-hour incubation at 37°C when gametocyte infected red blood cells were reconstituted in RPMI/serum. Methylene-blue, MMV693183, DDD107498, atovaquone and P218 showed potent transmission-blocking activity in the TB-DMFA, and both atovaquone and the novel antifolate P218 were potent inhibitors of sporogonic development in the SPORO-DMA. This work establishes a pipeline for the integral use of field isolates to assess the transmission-blocking capacity of antimalarial drugs to block transmission that should be validated in future studies.

3H-3000, AN FGFR2B-SPECIFIC MONOCLONAL ANTIBODY, SHOWS SUPERIOR TUMOR KILLING IN VIVO

Abstract Background and significance Fibroblast growth factor receptor 2b (FGFR2b), a splice isoform of FGFR2, is found to overexpress across multiple cancers types and promotes dysregulated tyrosine kinase activation, resulting in tumor cell proliferation and unchecked malignancy. Cohort studies reveal FGFR2b overexpression and/or amplification in Gastric cancer (~30.2%), squamous non-small cell lung cancer (~20.8%), and endometrial carcinoma (~40%). About 80–85% patients who have advanced HER2-negative gastro-esophageal cancer undergoes approximately 12-14 months of median overall survival (mOS). Thus, there is an urgent need for novel and effective molecular targeted agents. With the recent advancement of mechanistic studies, however, FGFR2b is becoming the optimal target of multiple modalities such as mAb, bispecifics, or antibody-drug conjugate. Bemarituzumab, a FGFR2b blocking antibody, developed by Five Prime clinically demonstrates the safety of FGFR2b target and exhibits preliminary efficacy in advanced GE/GEJ adenocarcinoma patients with overexpression of FGFR2 in at least 5% or 10% of tumor cells. 3H Pharmaceuticals developed a FGFR2b-specific mAb, 3H-3000, of high-affinity, differentiated epitope and enhanced ADCC effect for FGFR2b-overexpressing gastric cancer or other FGFR2b-associated cancer types. In the meantime, we will also explore the versatility of this mAb in other format and in the combination with small molecules that will bring about a wider therapeutic spectrum. Method and Result 3H-3000 is a humanized IgG1kappa antibody with a single digit nM affinity for FGFR2b and no binding to other FGFR2 isoforms. 3H-3000 shows potent proliferation-inhibitive effects on FGFR2b-overexpressing human tumor cells. In gastric cancer cell line SNU16, 3H-3000 can fully inhibit FGF7-induced phosphorylation of FGFR2b and SNU16 proliferation in vitro. On top of signaling blocking, we strongly believe efficacy of antibody-dependent cell cytotoxicity (ADCC) is another viable mechanism for growth factor-targeting therapy. Therefore, 3H-3000 was further engineered with a 20-fold ADCC enhancement which is validated through a CD16-F158 variant-based reporter system. In FGFR2b-overexpressing human gastric cancer SNU16 or OCUM-2M xenograft model, 3H-3000 was shown to inhibit tumor growth and even induce regression, which is rather unexpected given the relative low expression of FGFR2b on SNU16 and none of the competitors exhibit similar phenomenon. With potent efficacy of tumor inhibition and killing, and excellent biophysical characteristics and developability of 3H-3000, we expect to push the molecule to clinical development in the middle of 2024. Conclusion 3H-3000 is a potent FGFR2b blocker with well-defined ADCC efficacy enhancement. It demonstrates strong blocking activity of FGFR2 signaling, strikingly enhanced ADCC activity in vitro and potent efficacy of tumor inhibition in vivo. These data strongly support its clinical development in FGFR2b-overexpressing cancers. In parallel, 3H Pharmaceuticals are also developing FGFR2- selectively tyrosine kinase inhibitors targeting FGFR2 mutations or fusion. We propose a combination of small molecule FGFR2 inhibitors and mAb of FGFR2b specificity will significantly broaden the therapeutic spectrum of heterogenous tumors where mechanism is centered around FGFR2b alteration including mutation, fusion, and overexpression.

Evaluation of the Operative Programming at the CHU Gabriel TOURE of Bamako-Mali

In Mali, particularly in CHU Gabriel TOURE, organization of block activities is always problematic due to operative programming ignorance by staff of sector and other proximity, thus causing a blow to the good functioning of block. Objectives: Determine the knowledge level of staff intervening in block; to describe the existence of block operative charter functioning, know the existence of block operative components, Analyze the unrolling operative program. Methodology: We carried out a prospect, descriptive and transversal study to CHU Gabriel TOURE close to staff practicing to the operative blocks and other relation services; the sampling was probabilistic, based on systematic random technic. Result: Decisional proceedings and coordination in the block are ignored by the all respondent staff (100%). 50, 57% of respondent staff have witnessed the inobservance of hygiene rules concerning the patient, professionals, staffs in training, visitors, equipments, locals and environment. 75, 87% of respondents have testified a specify date and hour existence of programming meetings, but which are not surely respected according to 58, 63% of those same respondents. As far as 72, 44% have testified a fix hour existence to the bloc opening while.77, 01% have found regular hour inexistence to the startup of program. It also exists that a room is defined for each specialty working in the block say 65, 52% of respondent staff. 63, 22% of respondents affirmed that there is no own channel pour patient and material. Moreover it states that none of investigated staff does not know the responsible of block team coordination (100%). There are no established punishments at the block also supporting modalities of dysfunction and conflicts, respectively say 57, 48% and 70, 12% of respondent staff. 100% of respondents testified collegiality’s absence in operative; programming meeting and that 51,72% of respondent staff judged that topics reading are not done during programming meeting ...

Effect of Linker Elongation on the VGSC Affinity and Anticonvulsant Activity among 4-Alkyl-5-aryl-1,2,4-triazole-3-thione Derivatives

The main aim of the current project was to investigate the effect of the linker size in 4-alkyl-5-aryl-1,2,4-triazole-3-thione derivatives, known as a group of antiepileptic drug candidates, on their affinity towards voltage-gated sodium channels (VGSCs). The rationale of the study was based both on the SAR observations and docking simulations of the interactions between the designed ligands and the binding site of human VGSC. HYDE docking scores, which describe hydrogen bonding, desolvation, and hydrophobic effects, obtained for 5-[(3-chlorophenyl)ethyl]-4-butyl/hexyl-1,2,4-triazole-3-thiones, justified their beneficial sodium channel blocking activity. The results of docking simulations were verified using a radioligand binding assay with [3H]batrachotoxin. Unexpectedly, although the investigated triazole-based compounds acted as VGSC ligands, their affinities were lower than those of the respective analogs containing shorter alkyl linkers. Since numerous sodium channel blockers are recognized as antiepileptic agents, the obtained 1,2,4-triazole derivatives were examined for antiepileptic potential using an experimental model of tonic–clonic seizures in mice. Median effective doses (ED50) of the compounds examined in MES test reached 96.6 ± 14.8 mg/kg, while their median toxic doses (TD50), obtained in the rotarod test, were even as high as 710.5 ± 47.4 mg/kg.

Novel H2S-Releasing Bifunctional Antihistamine Molecules with Improved Antipruritic and Reduced Sedative Actions.

Hydrogen sulfide (H2S) is an endogenous gasotransmitter with anti-inflammatory actions that also reduces itching. To test whether a combination of an antihistamine with a H2S donor has improved antipruritic efficacy, bifunctional molecules with antihistamine and H2S-releasing pharmacophores were synthesized and tested in vitro and in vivo. H2S release from the hybrid molecules was evaluated with the methylene blue and lead acetate methods, and H1-blocking activity was assessed by determining tissue factor expression inhibition. All new compounds released H2S in a dose-dependent manner and retained histamine blocking activity. Two compounds with the highest potency were evaluated in vivo for their antipruritic as well as sedative action; they proved to possess higher efficacy in inhibiting histamine-induced pruritus and decreased sedative effects compared to the parent compounds (hydroxyzine and cetirizine), suggesting that they exhibit superior antipruritic action and limited side effects that likely arise from the H2S-releasing moiety.

Molecular docking analysis of selected bioactive components of Glycyrrhiza glabra against bronchial asthma

Bronchial asthma is a chronic inflammatory disease of the lung by the combined action of various cytokines. As a result of the strong inflammatory response increased infiltration of cytokines result, damages respiratory epithelium, Hyperplasia of the trachealis muscle, and increased mucous production. Athimathura choornam is a promising drug used in all inflammatory conditions. Objective: To explore the efficacy of the Siddha formulation Athimathura choornam, an anti asthmatic drug using computational molecular docking analysis. Method: Based on the phytochemical study the active principles present in the plant Athimathuram were retrieved. 3D structure of the targets were retrieved from the repository and purified before the initiation of docking using the software. The potency of the drug was screened based on the binding of the ligands Asparagine, Liquiritin, and Glabridin with targets mentioned. These results were compared with the standard drugs such as Cetirizine, Salicylic acid, Diclofenac, Ibuprofen, and Celecoxib. Results and Conclusion: Liquiritin has 9 interactions (90%) similar to that of Ibuprofen, 14 interactions (90%) similar to that of Citrazinehence , 5 interactions (100%) similar to that of salicylic acid hence it has promising COX 1 inhibition ,Histamine 1 blocking activity and Prostaglandin Synthase inhibition activity. Asparagine has 3 interactions (60%) similar to Celecoxib, has promising COX 2 inhibition activity. Glabridin has 2 interactions (50%) similar to that of Diclofenac hence it has promising IL6 inhibition activity.

Aqueous Extract of Malus domestica Inhibits Human Platelet Aggregation Induced by Multiple Agonists

Cardiovascular diseases such as hypertension, myocardial infarction, and atherosclerosis are the major cause of morbidity and mortality in humankind and not only afflict industrialized nations but also affect developing countries such as Pakistan. We attempted to screen one of the most common fruits, Malus domestica (MD or apple), used in Pakistan for its potential cardio-protective effects. The crude aqueous extract (MD-Aq) was prepared and investigated for inhibitory activity against several important cardiovascular drug targets. Activities of antioxidant enzymes such as glutathione peroxidase (GPx) and superoxide dismutase (SOD) were studied, as well as total antioxidant status (TAS). Calcium channel blocking activity was measured using guinea pig ileum in an isolated tissue bath setup. Platelet aggregation studies were carried out using a dual-channel aggregometer. MD-Aq showed dose-dependent improvement in the GPX activity. The highest SOD levels were observed with 10 mg/ml and were 185 U/L compared to 174 U/L for saline, which means no significant effect by MD-Aq. TAS levels were highest at 10 mg/ml of MD-Aq, reaching 1.75 mmol/L of plasma. At 10 mg/ml, close to 90% inhibition of KCl-induced opening of calcium channels was observed, compared with the effect of 1mM Verapamil. At each dose of 1, 5, and 10 mg/ml, a significantly higher arachidonic acid-induced inhibition of platelet aggregation was observed as compared to the saline effect. MD-Aq effects on platelet-activating factor-induced platelet aggregation were less potent. We concluded that MD-Aq could elevate GPX and TAS levels, is inactive at SOD, and is excellent as a calcium channel blocker, a more potent blocker of arachidonic acid-induced aggregation than platelet-activating factor-induced aggregation. These activities can help treat various cardiovascular diseases.

Effect of Dihydroartemisinin on contractility to Drugs in isolated smooth muscle Preparations in guinea pig in vitro models

This study was aimed at evaluating the effect of Dihydroartemisinin (DHA)on contractility to drugs in ileum isolated smooth muscle preparations in guinea pigs using in Vitro experimental procedures / standard protocols in an organ bath set up. dihydroartemisinin (1.0 x 10 - 8 - 1.0 x 10 – 5mg/mL) when applied alone and separately excited marked variable effects on guinea pig ileum . In some preparation it showed no response, while in others it produced slight phasic contraction when external calcium (Ca2+) ion was introduced. The slight phasic contractile activity was abolished by verapamil (5x10-3mg/mL). Dihydroartemisinin (1.0 x 10 - 6 - 1.0 x 10 – 5mg/mL) caused marked significant induced contraction – dependent inhibition of acetylcholine, potassium chloride and histamine in depolarizing tyrode solution (p &lt; 0.05).The Inhibitory response maxima of dihydroartemisinin on acetylcholine induced contraction is 17.0±0.1 mm(65.56% inhibition) ; and is moderate when compared to the inhibitory effect of atropine (10-5 M). The result shows that dihydroartemisinin seems to act via non-specific receptor mechanism, with appreciable calcium channel blocking activity and it is safe at therapeutic doses.