scholarly journals Synthesis and antiplasmodial activity of regioisomers and epimers of second-generation dual acting ivermectin hybrids

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Lovepreet Singh ◽  
Diana Fontinha ◽  
Denise Francisco ◽  
Miguel Prudêncio ◽  
Kamaljit Singh
Keyword(s):  
First Generation ◽  
Second Generation ◽  
Blood Stage ◽  
Antiplasmodial Activity ◽  
Vector Borne Diseases ◽  
Insecticidal Effect ◽  
Successful Isolation ◽  
Molecular Hybrids

AbstractWith its strong effect on vector-borne diseases, and insecticidal effect on mosquito vectors of malaria, inhibition of sporogonic and blood-stage development of Plasmodium falciparum, as well as in vitro and in vivo impairment of the P. berghei development inside hepatocytes, ivermectin (IVM) continues to represent an antimalarial therapeutic worthy of investigation. The in vitro activity of the first-generation IVM hybrids synthesized by appending the IVM macrolide with heterocyclic and organometallic antimalarial pharmacophores, against the blood-stage and liver-stage infections by Plasmodium parasites prompted us to design second-generation molecular hybrids of IVM. Here, a structural modification of IVM to produce novel molecular hybrids by using sub-structures of 4- and 8-aminoquinolines, the time-tested antiplasmodial agents used for treating the blood and hepatic stage of Plasmodium infections, respectively, is presented. Successful isolation of regioisomers and epimers has been demonstrated, and the evaluation of their in vitro antiplasmodial activity against both the blood stages of P. falciparum and the hepatic stages of P. berghei have been undertaken. These compounds displayed structure-dependent antiplasmodial activity, in the nM range, which was more potent than that of IVM, its aglycon or primaquine, highlighting the superiority of this hybridization strategy in designing new antiplasmodial agents.

scholarly journals Poly(amidoamine) Hydrogels as Scaffolds for Cell Culturing and Conduits for Peripheral Nerve Regeneration

2011 ◽  
Vol 2011 ◽  
pp. 1-20 ◽  
Author(s):  
Fabio Fenili ◽  
Amedea Manfredi ◽  
Elisabetta Ranucci ◽  
Paolo Ferruti
Keyword(s):  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
First Generation ◽  
Second Generation ◽  
Peripheral Nerve Regeneration ◽  
Biological Properties ◽  
Cell Culturing ◽  
First And Second Generation

Biodegradable and biocompatible poly(amidoamine)-(PAA-) based hydrogels have been considered for different tissue engineering applications. First-generation AGMA1 hydrogels, amphoteric but prevailing cationic hydrogels containing carboxylic and guanidine groups as side substituents, show satisfactory results in terms of adhesion and proliferation properties towards different cell lines. Unfortunately, these hydrogels are very swellable materials, breakable on handling, and have been found inadequate for other applications. To overcome this problem, second-generation AGMA1 hydrogels have been prepared adopting a new synthetic method. These new hydrogels exhibit good biological propertiesin vitrowith satisfactory mechanical characteristics. They are obtained in different forms and shapes and successfully testedin vivofor the regeneration of peripheral nerves. This paper reports on our recent efforts in the use of first-and second-generation PAA hydrogels as substrates for cell culturing and tubular scaffold for peripheral nerve regeneration.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

Current Challenges in the Development of Vaccines and Drugs Against Emerging Vector-borne Diseases

2019 ◽  
Vol 26 (16) ◽  
pp. 2974-2986 ◽  
Author(s):  
Kwang-sun Kim
Keyword(s):  
New Host ◽  
In Vivo Models ◽  
Vector Borne Diseases ◽  
Novel Drugs ◽  
Huge Impact ◽  
Tick Borne Disease ◽  
Vector Borne ◽  
Living Organisms

Vectors are living organisms that transmit infectious diseases from an infected animal to humans or another animal. Biological vectors such as mosquitoes, ticks, and sand flies carry pathogens that multiply within their bodies prior to delivery to a new host. The increased prevalence of Vector-Borne Diseases (VBDs) such as Aedes-borne dengue, Chikungunya (CHIKV), Zika (ZIKV), malaria, Tick-Borne Disease (TBD), and scrub typhus has a huge impact on the health of both humans and livestock worldwide. In particular, zoonotic diseases transmitted by mosquitoes and ticks place a considerable burden on public health. Vaccines, drugs, and vector control methods have been developed to prevent and treat VBDs and have prevented millions of deaths. However, development of such strategies is falling behind the rapid emergence of VBDs. Therefore, a comprehensive approach to fighting VBDs must be considered immediately. In this review, I focus on the challenges posed by emerging outbreaks of VBDs and discuss available drugs and vaccines designed to overcome this burden. Research into promising drugs needs to be upgraded and fast-tracked, and novel drugs or vaccines being tested in in vitro and in vivo models need to be moved into human clinical trials. Active preventive tactics, as well as new and upgraded diagnostics, surveillance, treatments, and vaccination strategies, need to be monitored constantly if we are to manage VBDs of medical importance.

In vitro and in vivo antiplasmodial activity of novel quinoline derivative compounds by molecular hybridization

2021 ◽  
Vol 215 ◽  
pp. 113271
Author(s):  
Juliane Aparecida Marinho ◽  
Daniel Silqueira Martins Guimarães ◽  
Nícolas Glanzmann ◽  
Giovana de Almeida Pimentel ◽  
Izabelle Karine da Costa Nunes ◽  
...  
Keyword(s):  
Quinoline Derivative ◽  
Antiplasmodial Activity ◽  
Molecular Hybridization

scholarly journals Identification of Novel Mutations Responsible for Resistance to MK-2048, a Second-Generation HIV-1 Integrase Inhibitor

2010 ◽  
Vol 84 (18) ◽  
pp. 9210-9216 ◽  
Author(s):  
Tamara Bar-Magen ◽  
Richard D. Sloan ◽  
Daniel A. Donahue ◽  
Björn D. Kuhl ◽  
Alexandra Zabeida ◽  
...  
Keyword(s):  
Viral Replication ◽  
First Generation ◽  
Second Generation ◽  
Integrase Inhibitor ◽  
Replication Capacity ◽  
Strand Transfer ◽  
Viral Replication Capacity ◽  
Transfer Inhibitor ◽  
Potential Basis

ABSTRACT MK-2048 represents a prototype second-generation integrase strand transfer inhibitor (INSTI) developed with the goal of retaining activity against viruses containing mutations associated with resistance to first-generation INSTIs, raltegravir (RAL) and elvitegravir (EVG). Here, we report the identification of mutations (G118R and E138K) which confer resistance to MK-2048 and not to RAL or EVG. These mutations were selected in vitro and confirmed by site-specific mutagenesis. G118R, which appeared first in cell culture, conferred low levels of resistance to MK-2048. G118R also reduced viral replication capacity to approximately 1% that of the isogenic wild-type (wt) virus. The subsequent selection of E138K partially restored replication capacity to ≈13% of wt levels and increased resistance to MK-2048 to ≈8-fold. Viruses containing G118R and E138K remained largely susceptible to both RAL and EVG, suggesting a unique interaction between this second-generation INSTI and the enzyme may be defined by these residues as a potential basis for the increased intrinsic affinity and longer “off” rate of MK-2048. In silico structural analysis suggests that the introduction of a positively charged arginine at position 118, near the catalytic amino acid 116, might decrease Mg2+ binding, compromising enzyme function and thus leading to the significant reduction in both integration and viral replication capacity observed with these mutations.

In vitro and in vivo Antiplasmodial Activity of Momordica balsamina Alone or in a Traditional Mixture

Chemotherapy ◽  
2006 ◽  
Vol 52 (6) ◽  
pp. 288-292 ◽  
Author(s):  
F. Benoit-Vical ◽  
P. Grellier ◽  
A. Abdoulaye ◽  
I. Moussa ◽  
A. Ousmane ◽  
...  
Keyword(s):  
Antiplasmodial Activity

scholarly journals In vitro Assessment of Antiplasmodial Activity and Acute Oral Toxicity of Dissotis rotundifolia Extracts and Fractions on Plasmodium falciparum Strains

2020 ◽  
pp. 8-19
Author(s):  
Rock Djehoue ◽  
Rafiou Adamou ◽  
Abdou Madjid O. Amoussa ◽  
Adande A. Medjigbodo ◽  
Anatole Laleye ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Acute Toxicity ◽  
Ethanolic Extract ◽  
Antiplasmodial Activity ◽  
Oral Toxicity ◽  
Aqueous Fraction ◽  
Vector Borne Diseases ◽  
Natural Substances ◽  
Study Laboratory

Aim: Dissotis rotundifolia were selected after an ethnopharmacological survey conducted on plants used traditionally for malaria treatment in South Benin, with the aim of discovering new natural active extracts against malaria parasites. Place and Duration of Study: Laboratory of Biochemistry and Bioactive Natural Substances, University of Abomey-Calavi (Benin)/ Laboratory of Infectious Vector Borne Diseases, Regional Institute of Public Health (Benin)/ Laboratoire d’Histologie, de Cytogénétique et d’Embryologie, Faculté des Sciences de la Santé (Benin). The study was conduct from October 2018 to June 2019 in Benin. Methodology: The antiplasmodial activity of the plant extracts was evaluated using the parasite lactate dehydrogenase (pLDH) immunodetection assay. The extract with the best antiplasmodial activity were used on Wistar rats for acute toxicity. Results: Ethanolic extract of Dissotis rotundifolia showed promising activity (Isolate: IC50 = 22.58 ± 1.12 µg/mL; 3D7: IC50 = 6.81 ± 0.85 µg/mL) on Plasmodium falciparum compared to the aqueous extract (Isolate: IC50 > 100 µg/mL; 3D7: IC50> 100 µg/mL). The aqueous fraction of D. rotundifolia exhibit highly potent activity against P. falciparum strain (Isolate: IC50 > 100 µg/mL μg/mL; 3D7: IC50 = 4.05 ± 0.72 μg/mL). Haemolytic effect of actives extracts and fractions is less than 5%. Ethanolic extract of D. rotundifolia revealed no obvious acute toxicity in rat up to the highest dose administered (2000 mg/kg). Conclusion: This study justifies traditional uses of D. rotundifolia against malaria. A bioguided fractionation of these extracts would identify molecules responsible for their antiplasmodial activity. Moreover, these results could lead to the design of improved traditional medicines in the basis of this plant.

scholarly journals Exploring heteroaromatic rings as a replacement for the labile amide of antiplasmodial pantothenamides

2020 ◽  
Author(s):  
Jinming Guan ◽  
Christina Spry ◽  
Erick T. Tjhin ◽  
Penghui Yang ◽  
Tanakorn Kittikool ◽  
...  
Keyword(s):  
Contact Time ◽  
High Selectivity ◽  
Amide Group ◽  
Antiplasmodial Activity ◽  
Time Data ◽  
Facile Synthesis ◽  
Isoxazole Derivative ◽  
Nanomolar Range

ABSTRACTThe Plasmodium parasites that cause malaria are adept at developing resistance to antimalarial drugs, necessitating the search for new antiplasmodials. Although several amide analogs of pantothenate (pantothenamides) show potent antiplasmodial activity, hydrolysis by pantetheinases (or vanins) present in blood rapidly inactivates them. We report herein the facile synthesis and biological activity of a small library of pantothenamide analogs in which the labile amide group is replaced with a variety of heteroaromatic rings. Several of the new analogs display antiplasmodial activity in the nanomolar range against P. falciparum and/or P. knowlesi in the presence of pantetheinase. A previously reported triazole and an isoxazole derivative presented here were further characterized and found to possess high selectivity indices, medium or high Caco-2 permeability, and medium or low microsomal clearance in vitro. Although we show here that the two compounds fail to suppress proliferation of P. berghei in vivo, pharmacokinetic and contact time data presented provide a benchmark for the compound profile required to achieve antiplasmodial activity in mice and should facilitate lead optimization.

Immunocytochemical Analysis of Murine Peritoneal Macrophages Treated with “Poly-Plat”, an in Vitro and in Vivo Study

1998 ◽  
Vol 4 (S2) ◽  
pp. 1122-1123
Author(s):  
H. J. Muenchen ◽  
S.K. Aggarwal
Keyword(s):  
Immune System ◽  
Mechanism Of Action ◽  
Second Generation ◽  
Peritoneal Macrophages ◽  
In Vivo Study ◽  
Immunocytochemical Analysis ◽  
Murine Peritoneal Macrophages

Poly-[(trans-1,2-diaminocyclohexane) platinumj-carboxyamylose (“poly-plat“) is a second generation analog of cisplatin which enhances the immune system with greater efficacy in vitro and in vivo “Poly-plat” contains 1/5 the platinum of CDDP and demonstrates less toxicity. In order to understand the mechanism of action of this compound an in vitro and in vivo study was performed. Swiss Webster mice and isolated murine peritoneal macrophages were treated with “poly-plat” (10 mg/kg). The Swiss Webster mice were given bolus injections and sacrificed at 2 and 12 days. Peritoneal macrophages were then isolated and allowed to incubate in culture for 24 h. Peritoneal macrophages were also isolated from normal mice and treated with the drugs for 2 h. After treatments the macrophages were placed in fresh media and allowed to incubate 24 h. Supematants were isolated at various times during culture for immunocytochemical analysis.Both in vitro and in vivo studies showed enhanced immunostimulation after their respective treatments.

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