Ispitivanje antimalarijskog potencijala novosintetisanih aminohinolina u in vitro i in vivo sistemima

Malaria, a disease which affects millions of people worldwide, is a parasitic infection caused by protozoans of the Plasmodium genus. Five Plasmodium species are known to cause human malaria, including P. falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi. The most virulent one is P. falciparum, and the malaria which it causes is characterized by the most severe clinical presentation as well as the highest mortality rate. The vectors responsible for the transmission of this disease are female mosquitoes of the Anopheles genus. Malaria is the greatest health problem facing developing countries, with the highest morbidity and mortality rates in Africa and Southeast Asia. Moreover, due to climate change and mass human migration, autochthonous cases of malaria are increasingly appearing sporadically (Corsica, Italy, Spain) or even as local epidemics (Greece), in countries or regions in which the disease was considered eradicated. It is important to emphasize that the prevention and treatment of malaria are possible. However, Plasmodium parasites are developing resistance to nearly all conventional antimalarials, Anopheles vectors are becoming resistant to insecticides, and no vaccine exists to date. Given the current situation, there is an urgent need for new antimalarial compounds. Synthetic quinoline derivatives hold the most promise, with 4-aminoquinolines being the most suitable for chemical modifications. With the aim to expand knowledge in the field of malarial chemotherapy, potential antimalarial activity of 37 novel aminoquinolines with chemical modifications at the aminoquinoline moiety and side chain, synthesized at the University of Belgrade Faculty of Chemistry, were evaluated in both in vitro and in vivo model systems. In vitro evaluation of the antimalarial activity of the synthesized compounds was performed using the colorimetric lactate dehydrogenase (LDH) assay. Two strains of P. falciparum were used, one, 3D7, sensitive to chloroquine (CQ), and one, Dd2, resistant to CQ. Compounds were first screened at a concentration of 500 nM, and selected compounds were then titrated to determine their half maximal inhibitory concentration (IC50). CQ was used as a positive control. In vivo antimalarial activity was investigated using a modified Thompson test. C57Bl/6 female mice were infected with the ANKA strain of P. berghei and monitored for 30 days. Investigation of the animalarial activity of the experimental compounds was preceded by a series of experiments in which healthy mice treated with the compounds during 3 consecutive days at a dose of 160 mg/kg/day were clinically monitored; those that showed signs of gross toxicity were excluded from further investigation...Malarija, bolest koja pogađa milione ljudi širom sveta, je parazitska infekcija uzrokovana protozoama roda Plasmodium. Danas je poznato pet vrsta koje izazivaju malariju kod čoveka: P. falciparum, P. vivax, P. malariae, P. ovale i P. knowlesi. Najvirulentnija vrsta je P. falciparum, a malariju koju ona izaziva karakterišu najteži klinički tok bolesti kao i najviša stopa smrtnosti. Vektori odgovorni za prenošenje ove bolesti su ženke komaraca roda Anopheles. Malarija predstavlja najveći zdravstveni problem sa kojim se suočavaju zemlje u razvoju, a najviše stope morbiditeta i mortaliteta beleže se u zemljama Afrike i Jugoistočne Azije. Međutim, usled klimatskih promena i masovnih migracija stanovništva, autohtoni slučajevi malarije sve češće se pojavljuju sporadično (Korzika, Italija, Španija), pa i epidemijski (Grčka), i u zemljama ili regionima u kojima je ova bolest smatrana eradikovanom. Važno je naglasiti da su prevencija i terapija malarije moguće. Međutim, paraziti Plasmodium postaju rezistentni na gotovo sve konvencionalno dostupne antimalarike, anofelični vektori su rezistentni na insekticide, a vakcina i dalje ne postoji. S obzirom na opisanu situaciju, postoji hitna potreba za novim antimalaricima. Sintetski hinolinski derivati najviše obećavaju, među kojima je za hemijske modifikacije najpogodnija struktura 4-aminohinolina. U cilju proširenja znanja u oblasti hemioterapije malarije ispitana je potencijalna antimalarijska aktivnost 37 novosintetisanih aminohinolina sa hemijskim modifikacijama na aminohinolinskom jezgru i bočnom lancu, sintetisanih na Hemijskom fakultetu Univerziteta u Beogradu, u in vitro i in vivo model sistemima. Ispitivanje antimalarijske aktivnost ovih jedinjenja u in vitro sistemu vršeno je kolorimetrijskim esejom laktat dehidrogenaze (LDH esej). Korišćena su dva soja P. falciparum, i to soj 3D7, koji je osetljiv na hlorokvin (CQ) i soj Dd2, koji je rezistentan na CQ. Prvi deo ispitivanja je činila faza skrininga u kojoj je aktivnost svih jedinjenja prema oba soja P. falciparum ispitana u koncentraciji od 500 nM, a odabrana jedinjenja su u sledećoj fazi titrirana do preciznih srednjih vrednosti inhibitornih koncentracija (IC50). CQ je korišćen kao pozitivna kontrola. Antimalarijska aktivnost u in vivo sistemu je ispitana primenom modifikovanog Thompson-ovog testa. Ženke miševa soja C57Bl/6 inficirane su ANKA sojem P. berghei i praćene 30 dana. Ispitivanju aktivnosti jedinjenja prethodila je faza kliničkog praćenja zdravih životinja tretiranih eksperimentalnim jedinjenjima tokom 3 dana u dozi od 160 mg/kg/dan..

Evaluation of the antimalarial potential of novel aminoquinolines in vitro and in vivo

Malarija, bolest koja pogađa milione ljudi širom sveta, je parazitska infekcija uzrokovana protozoama roda Plasmodium. Danas je poznato pet vrsta koje izazivaju malariju kod čoveka: P. falciparum, P. vivax, P. malariae, P. ovale i P. knowlesi. Najvirulentnija vrsta je P. falciparum, a malariju koju ona izaziva karakterišu najteži klinički tok bolesti kao i najviša stopa smrtnosti. Vektori odgovorni za prenošenje ove bolesti su ženke komaraca roda Anopheles. Malarija predstavlja najveći zdravstveni problem sa kojim se suočavaju zemlje u razvoju, a najviše stope morbiditeta i mortaliteta beleže se u zemljama Afrike i Jugoistočne Azije. Međutim, usled klimatskih promena i masovnih migracija stanovništva, autohtoni slučajevi malarije sve češće se pojavljuju sporadično (Korzika, Italija, Španija), pa i epidemijski (Grčka), i u zemljama ili regionima u kojima je ova bolest smatrana eradikovanom. Važno je naglasiti da su prevencija i terapija malarije moguće. Međutim, paraziti Plasmodium postaju rezistentni na gotovo sve konvencionalno dostupne antimalarike, anofelični vektori su rezistentni na insekticide, a vakcina i dalje ne postoji. S obzirom na opisanu situaciju, postoji hitna potreba za novim antimalaricima. Sintetski hinolinski derivati najviše obećavaju, među kojima je za hemijske modifikacije najpogodnija struktura 4-aminohinolina. U cilju proširenja znanja u oblasti hemioterapije malarije ispitana je potencijalna antimalarijska aktivnost 37 novosintetisanih aminohinolina sa hemijskim modifikacijama na aminohinolinskom jezgru i bočnom lancu, sintetisanih na Hemijskom fakultetu Univerziteta u Beogradu, u in vitro i in vivo model sistemima. Ispitivanje antimalarijske aktivnost ovih jedinjenja u in vitro sistemu vršeno je kolorimetrijskim esejom laktat dehidrogenaze (LDH esej). Korišćena su dva soja P. falciparum, i to soj 3D7, koji je osetljiv na hlorokvin (CQ) i soj Dd2, koji je rezistentan na CQ. Prvi deo ispitivanja je činila faza skrininga u kojoj je aktivnost svih jedinjenja prema oba soja P. falciparum ispitana u koncentraciji od 500 nM, a odabrana jedinjenja su u sledećoj fazi titrirana do preciznih srednjih vrednosti inhibitornih koncentracija (IC50). CQ je korišćen kao pozitivna kontrola. Antimalarijska aktivnost u in vivo sistemu je ispitana primenom modifikovanog Thompson-ovog testa. Ženke miševa soja C57Bl/6 inficirane su ANKA sojem P. berghei i praćene 30 dana. Ispitivanju aktivnosti jedinjenja prethodila je faza kliničkog praćenja zdravih životinja tretiranih eksperimentalnim jedinjenjima tokom 3 dana u dozi od 160 mg/kg/dan...Malaria, a disease which affects millions of people worldwide, is a parasitic infection caused by protozoans of the Plasmodium genus. Five Plasmodium species are known to cause human malaria, including P. falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi. The most virulent one is P. falciparum, and the malaria which it causes is characterized by the most severe clinical presentation as well as the highest mortality rate. The vectors responsible for the transmission of this disease are female mosquitoes of the Anopheles genus. Malaria is the greatest health problem facing developing countries, with the highest morbidity and mortality rates in Africa and Southeast Asia. Moreover, due to climate change and mass human migration, autochthonous cases of malaria are increasingly appearing sporadically (Corsica, Italy, Spain) or even as local epidemics (Greece), in countries or regions in which the disease was considered eradicated. It is important to emphasize that the prevention and treatment of malaria are possible. However, Plasmodium parasites are developing resistance to nearly all conventional antimalarials, Anopheles vectors are becoming resistant to insecticides, and no vaccine exists to date. Given the current situation, there is an urgent need for new antimalarial compounds. Synthetic quinoline derivatives hold the most promise, with 4-aminoquinolines being the most suitable for chemical modifications. With the aim to expand knowledge in the field of malarial chemotherapy, potential antimalarial activity of 37 novel aminoquinolines with chemical modifications at the aminoquinoline moiety and side chain, synthesized at the University of Belgrade Faculty of Chemistry, were evaluated in both in vitro and in vivo model systems. In vitro evaluation of the antimalarial activity of the synthesized compounds was performed using the colorimetric lactate dehydrogenase (LDH) assay. Two strains of P. falciparum were used, one, 3D7, sensitive to chloroquine (CQ), and one, Dd2, resistant to CQ. Compounds were first screened at a concentration of 500 nM, and selected compounds were then titrated to determine their half maximal inhibitory concentration (IC50). CQ was used as a positive control. In vivo antimalarial activity was investigated using a modified Thompson test. C57Bl/6 female mice were infected with the ANKA strain of P. berghei and monitored for 30 days. Investigation of the animalarial activity of the experimental compounds was preceded by a series of experiments in which healthy mice treated with the compounds during 3 consecutive days at a dose of 160 mg/kg/day were clinically monitored; those that showed signs of gross toxicity were excluded from further investigation..

Supplementary data for article : Konstantinović, J. M.; Selaković, M.; Srbljanovic, J.; Djurkovic-Djakovic, O.; Bogojević, K.; Sciotti, R.; Šolaja, B. A. Antimalarials with Benzothiophene Moieties as Aminoquinoline Partners. Molecules 2017, 22 (3). https://doi.org/10.3390/molecules22030343

Supplementary material for: [https://doi.org/10.3390/molecules22030343]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2441

Antimalarials with Benzothiophene Moieties as Aminoquinoline Partners

Malaria is a severe and life-threatening disease caused by Plasmodium parasites that are spread to humans through bites of infected Anopheles mosquitoes. Here, we report on the efficacy of aminoquinolines coupled to benzothiophene and thiophene rings in inhibiting Plasmodium falciparum parasite growth. Synthesized compounds were evaluated for their antimalarial activity and toxicity, in vitro and in mice. Benzothiophenes presented in this paper showed improved activities against a chloroquine susceptible (CQS) strain, with potencies of IC50 = 6 nM, and cured 5/5 Plasmodium berghei infected mice when dosed orally at 160 mg/kg/day x 3 days. In the benzothiophene series, the examined antiplasmodials were more active against the CQS strain D6, than against strains chloroquine resistant (CQR) W2 and multidrug-resistant (MDR) TM91C235. For the thiophene series, a very interesting feature was revealed: hypersensitivity to the CQR strains, resistance index (RI) of lt 1. This is in sharp contrast to chloroquine, indicating that further development of the series would provide us with more potent antimalarials against CQR strains

Examination of the antimalarial potential of experimental aminoquinolines: poor in vitro effect does not preclude in vivo efficacy

Malaria remains a major disease in the developing world and globally is the most important parasitic disease causing significant morbidity and mortality. Because of widespread resistance to conventional antimalarials, including chloroquine (CQ), new drugs are urgently needed. Here we report on the antimalarial efficacy, both in vitro and in vivo, of a series of aminoquinoline derivatives with adamantane or benzothiophene as a carrier. In vitro efficacy was evaluated by a lactate dehydrogenase (LDH) assay in cultures of a CQ-sensitive (3D7) and CQ-resistant (Dd2) strain of Plasmodium falcipanim. Of a series of 26 screened compounds, 12 that exerted a growth inhibition rate of gt = 5% were further examined in vitro to determine the 50% inhibitory concentration (IC50) values. Nine compounds shown in preliminary experiments to be non-toxic in vivo were evaluated in C57BL/6 mice infected with Plasmodium herghei ANKA strain using a modified Thompson test. All nine compounds examined in vivo prolonged the survival of treated versus untreated mice, four of which afforded gt = 60% survival. Most notably, two of these compounds, both with the adamantane carrier, afforded complete cure (100% survival and parasite clearance). Interestingly, one of these compounds had no in vitro effect against the CQ resistant P. falciparum strain. Better in vivo compared with in vitro results suggest a role for compound metabolites rather than the compounds themselves. The results presented here point to adamantane as a carrier that enhances the antimalarial potential of aminoquinolines

Epidemiology of Taenia solium infection in the Russian Federation in the last 20 years: a systematic review

Taenia solium is a zoonotic parasite that causes taeniasis and cysticercosis in humans (as final hosts) and cysticercosis in pigs (as intermediate hosts). The Russian Federation (RF) is traditionally considered as endemic for this zoonosis. However, the epidemiological data on T. solium infection have not been reviewed for the past 20 years, in which time dynamic economical and societal changes have occurred in the RF. The aim of this systematic review was to analyse the status of T. solium infection in RF in the 2000–2019 period. A literature search was conducted, which collected published articles, grey literature and official data on the epidemiology of T. solium taeniasis and cysticercosis in the RF published from 2000. From a total of 2021 articles and 24 official reports originally returned by the search, data were extracted from 12 full text articles and 11 official reports. Taenia solium taeniasis was continuously reported in the RF between 2000 and 2019, with a tenfold decrease in the incidence, from 0.2 per 100,000 population in 2000 to 0.023/100,000 in 2019. Also, the number of administrative units where taeniasis was detected continuously decreased. Cysticercosis in pigs had a declining trend after 2006. In conclusion, although decreasing, T. solium infection is still endemic in several regions and suspected to be endemic in most of the RF

SARS-CoV-2 specific antibody response after an mRNA vaccine as the third dose: homologous versus heterologous boost

Implementacija treće doze vakcine protiv SARS-CoV-2 u preporuke širom sveta otvorila je polje istraživanja heterologog pristupa revakcinaciji, odnosno kombinacije primarne serije vakcine i treće doze različite vakcinalne platforme. Iako je literatura bogata radovima na temu heterologog pristupa, imunogenost i trajanje humoralnog imunskog odgovora nakon kombinacije inaktivisane BBIBPCorV i iRNK vakcine nisu dovoljno istraženi. Stoga, cilj ove studije bio je ispitivanje razlike u imunogenosti i dugotrajnosti humoralnog imunskog odgovora u okviru perioda od šest meseci nakon treće doze kod homologog (tri doze BNT162b2) i heterologog (BBIBP-CorV/BNT162b2) pristupa revakcinaciji tokom Omikron talasa u Srbiji. U studiju je uključen 91 ispitanik, od kojih se 55 odlučilo za homologi a 36 za heterologi pristup. Serumi ispitanika analizirani su u četiri vremenske tačke: šest meseci nakon prve doze, a zatim tri nedelje, tri meseca i šest meseci nakon treće doze. IgG antitela specifična za receptor-vezujući domen “šiljastog” (eng. spike) proteina detektovana su BioMerieux VIDAS SARS-CoV-2 IgG testom. Tri nedelje nakon treće doze, oba pristupa revakcinaciji dovela su do značajnog porasta u koncentraciji antitela (p<0.0001). Štaviše, ispitanici koji su se opredelili za heterologu kombinaciju imali su statistički značajno više koncentracije antitela od homologe grupe, u kontrolnim vremenskim tačkama na tri nedelje i tri meseca nakon treće doze (p=0.025, p=0.0006). Međutim, značajan pad humoralnog imunskog odgovora zapažen je tokom vremena kod oba pristupa. Većina infekcija nakon vakcinacije registrovana je u periodu između tri i šest meseci nakon treće doze (n=22), a ukupna incidencija ovih infekcija za posmatrani period iznosila je 36.36% (20/55) nakon homologog i 16.67% (6/36) nakon heterologog pristupa. Međutim, ispitanici sa potvrđenom infekcijom nakon vakcinacije nisu imali pneumoniju niti su bili hospitalizovani. Iako je heterologi pristup indukovao više koncentracije antitela, naši rezultati ukazuju da su i heterologi i homologi pristup indukovali potentan humoralni imunski odgovor i odgovarajuću zaštitu od hospitalizacije i smrtnog ishoda tokom Omikron talasa. Međutim, opadanje imunskog odgovora opaženo kod oba vakcinalna pristupa u periodu od šest meseci, kao i konstantna opasnost od pojave novih pretećih varijanti, ukazuje na potrebu preispitivanja trenutne vakcinalne strategije.Worldwide implementation of the third dose of vaccine against SARS-CoV-2 opened a new field of research concerning the heterologous boost i.e., the combination of the primary vaccine series and a different vaccinal platform for the third dose. Although literature is replete with studies of heterologous boosts, longevity and immunogenicity of the inactivated BBIBP-CorV and mRNA BNT162b2 combination remains under-explored. Thus, the aim of this study was to evaluate the differences in immunogenicity and longevity of the humoral immune response within six months after the third dose in both homologous (BNT162b2) and heterologous (BBIBP-CorV/BNT162b2) vaccination setting, and to assess the real-life data in the middle of the Omicron surge in Serbia. A total of 91 individuals were included in this study, of which 55 received homologous and 36 heterologous boost. Serum samples were analyzed at four timepoints: six months after the first dose; three weeks, three months, and six months after the third dose. Specific IgG antibodies against the receptor-binding domain of the spike protein were detected using BioMerieux VIDAS SARS-CoV-2 IgG kit. Both groups showed a highly significant increase in antibody concentrations (p<0.0001) three weeks after the boost. Furthermore, comparison per timepoint has shown that recipients of heterologous boost had significantly higher antibody concentrations than homologous group, at three weeks and three months after the boost (p=0.025, p=0.0006). However, a significant decline in antibody response over time was noted for both strategies. The majority of breakthrough infections were registered in the period between three and six months after the boost (n=22).Furthermore, total incidence was estimated at 36.36% (20/55) for homologous group, and 16.67% (6/36) for heterologous group. Most importantly, none of the recipients of the third dose developed pneumonia during the breakthrough infection, and none were hospitalized. In conclusion, although heterologous approach resulted in higher antibody concentrations, our findings imply that both homologous and heterologous boost induce potent humoral immune response and adequate protection against hospitalization and death in the Omicron setting. However, waning immune response registered for both types of boosts within six months and constant threats of new emerging variants, calls for an update of vaccine strategy

Prospective Cohort Study of the Kinetics of Specific Antibodies to SARS-CoV-2 Infection and to Four SARS-CoV-2 Vaccines Available in Serbia, and Vaccine Effectiveness: A 3-Month Interim Report

Real-life data on the performance of vaccines against SARS-CoV-2 are still limited. We here present the rates of detection and levels of antibodies specific for the SARS-CoV-2 spike protein RBD (receptor binding domain) elicited by four vaccines available in Serbia, including BNT-162b2 (BioNTech/Pfizer), BBIBP-CorV (Sinopharm), Gam-COVID-Vac (Gamaleya Research Institute) and ChAdOx1-S (AstraZeneca), compared with those after documented COVID-19, at 6 weeks and 3 months post first vaccine dose or post-infection. Six weeks post first vaccine dose, specific IgG antibodies were detected in 100% of individuals fully vaccinated with BNT-162b2 (n = 100) and Gam-COVID-Vac (n = 12) and in 81.7% of BBIBP-CorV recipients (n = 148), while one dose of ChAdOx1-S (n = 24) induced specific antibodies in 75%. Antibody levels elicited by BNT-162b2 were higher, while those elicited by BBIBP-CorV were lower, than after SARS-CoV-2 infection. By 3 months post-vaccination, antibody levels decreased but remained ≥20-fold above the cut-off in BNT-162b2 but not in BBIBP-CorV recipients, when an additional 30% were seronegative. For all vaccines, antibody levels were higher in individuals with past COVID-19 than in naïve individuals. A total of twelve new infections occurred within the first 3 months post-vaccination, eight after the first dose of BNT-162b2 and ChAdOx1-S (one each) and BBIBP-CorV (six), and four after full vaccination with BBIBP-CorV, but none required hospitalization

Novi derivati 4-aminohinolina kao umereni inhibitori parazita

Synthesis of novel aminoquinoline derivatives has been accomplished and their activity against malaria strains has been examined. The compounds showed moderate in vitro antimalarial activity against two P. falciparum strains, 3D7 (CQ susceptible clone) and Dd2 (CQ resistant clone). Three aminoquinolines were further examined for antimalarial efficacy in a mouse model using a modified Thompson test. In this model, mice were infected with P. berghei-infected red blood cells, and drugs were administered orally. Antimalarial 3 was found toxic at a dose of 320 (mg/kg)/day in 3/6 mice, however, 2/6 mice of the same group survived through day 31, and one of them was cured

Postnatal ocular toxoplasmosis in immunocompetent patients

Introduction: Ocular toxoplasmosis is the most common cause of infectious posterior uveitis worldwide. It can be prenatal or postnatal in origin. Despite estimations that postnatal ocular toxoplasmosis is more prevalent, only several cases of proven postnatal ocular toxoplasmosis have been reported in non-epidemic settings. Here, the clinical evolution of ocular toxoplasmosis of conclusively proven postnatal origin in immunocompetent patients is reported.Methodology: Postnatal ocular toxoplasmosis was diagnosed based on clinical diagnosis supported by the longitudinal detection of Toxoplasma gondii-specific IgG, IgM and IgA antibodies in the serum as well as by direct detection of the parasite (bioassay) and/or its DNA (real-time PCR) in aqueous humor.Results: Three cases involved adults in whom ocular toxoplasmosis developed during primary T. gondii infection, as part of the clinical presentation in two and as the sole manifestation in one patient. The fourth patient was a case of inactive ocular toxoplasmosis in a 14-year-old boy, where postnatal infection was confirmed by exclusion of maternal infection. The causative parasite strain was genotyped in only one case and it belonged to genotype II, the dominant type in Europe. One patient acquired the infection in Africa, suggesting an atypical strain.Conclusions: The distinction between prenatal and postnatal ocular toxoplasmosis is only possible in particular clinical situations, and requires extensive laboratory investigation. Genotyping of the parasite strain involved may be important, particularly if atypical strains are suspected, requiring tailored treatment approaches