P200 Development of new antimalarial drugs : in vitro and in vivo antimalarial activity of endoperoxides

Background. Malaria is among the leading causes of mortality and morbidity. Moreover, the emergence of resistance to antimalarial drugs is a major problem in controlling the disease. This makes the development of novel antimalarial drugs a necessity. Medicinal plants are important sources in discovering antimalarial drugs. Schinus molle is claimed for its antimalarial effect in Ethiopian folkloric medicine and endowed with in vitro antiplasmodial activity. In the present study, the in vivo antimalarial activity of the plant was investigated. Methods. Acute toxicity was carried out using a standard procedure. To screen the in vivo antimalarial potential of the S. molle against Plasmodium berghei (ANKA), a 4-day suppressive test was employed. The extracts and fractions were given to infected mice by oral gavage at 100, 200, and 400 mg/kg/day for four consecutive days. Parameters such as parasitemia were then evaluated. Results. Any sign of toxicity was not observed in the oral acute toxicity test. The crude extracts and solvent fractions exerted a significant (p<0.05) inhibition of parasite load compared to the negative control. The highest inhibition (66.91%) was exhibited by the 400 mg/kg/day dose of 80% methanolic crude extract. Among the fractions, chloroform fraction demonstrated maximal chemosuppressive effect (55.60%). Moreover, crude extracts and solvent fractions prevented body weight loss, reduction in temperature, and anemia compared to the negative control. Except the aqueous fraction, the tested plant extracts were able to significantly prolong the survival time of infected mice. Conclusion. The findings of the present study confirmed the safety and a promising in vivo antimalarial activity of S. molle, thus supporting the traditional claim and in vitro efficacy. In-depth investigations on the plant, however, are highly recommended.

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Antimalarial activity of traditional Kampo medicine Coptis Rhizome extract and its major active compounds

10.21203/rs.2.19890/v1 ◽

2020 ◽

Author(s):

Awet Alem Teklemichael ◽

Shusaku Mizukami ◽

Kazufumi Toume ◽

Farhana Mosaddeque ◽

Mohamed Gomaa Kamel ◽

...

Keyword(s):

Herbal Medicine ◽

Adult Mouse ◽

Antimalarial Activity ◽

Antimalarial Drugs ◽

Active Components ◽

Crude Drug ◽

Low Cytotoxicity ◽

Test Treatment

Abstract Background: The herbal medicine has been an attractive source of new antimalarial drugs exemplified by quinine and artemisinin, thus we examined a variety of Japanese traditional herbal medicine (Kampo) for their potential antimalarial activities.Methods: We designed a comprehensive screening to identify novel antimalarial drugs from a library of Kampo crude drug extracts (n = 120). The antimalarial activity was initially evaluated in vitro against chloroquine/mefloquine-sensitive (3D7) and -resistant (Dd2) strains of Plasmodium falciparum. The cytotoxicity was also evaluated using primary Adult Mouse Brain cells. Subsequently, major active components of Kampo crude drug extracts showing high antimalarial activities and low cytotoxicity were further evaluated. Finally, the in vivo antimalarial activities of promising Kampo crude drug extract was investigated using P. yoelii infected mouse model in a seven-day suppressive test (treatment start two hours after challenge infection and continue for seven days).Results: Out of 120 extracts, Coptis Rhizome showed the highest antimalarial activity (IC50 1.9 µg/mL of 3D7 and 4.85 µg/mL of Dd2) with a high selectivity index (SI) > 263 (3D7) and > 103 (Dd2). Three major components in Coptis Rhizome also showed antimalarial activities with IC50 ranging from 1.1 to 6.0 µM (against 3D7) and from 3.1 to 11.8 µM (against Dd2). Among them, coptisine chloride exhibited the highest antimalarial activity (IC50 1.1 µM against 3D7 and 3.1 µM against Dd2) with SI of 37.8 and 13.2, respectively. Furthermore, Coptis Rhizome exhibited significant antimalarial activity in mice infected with P. yoelii 17X strain with respect to its activity on parasite suppression consistently throughout the entire test period (P < 0.05).Conclusion: Coptis Rhizome showed a significant in vivo antimalarial activity in mice infected with P. Yoelii, thus it is a potential natural resource for antimalarials and its component coptisine chloride is a promising antimalarial lead compound.

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Antimalarial Activity of Curcuma Caesia Against 3D7 and K1 Strains of Plasmodium Falciparum

10.21203/rs.3.rs-32452/v1 ◽

2020 ◽

Author(s):

Monika Chaturvedi ◽

Reena Rani ◽

Dushyant Sharma ◽

Jaya Parkash Yadav

Keyword(s):

Plasmodium Falciparum ◽

Ethyl Acetate ◽

In Silico ◽

Antimalarial Activity ◽

Antimalarial Drugs ◽

Mechanism Study ◽

Effective Development ◽

Ethyl Acetate Extracts

Abstract Background: Malaria is a severe and sometimes mortal tropical disease that spreads through parasites. The purpose of the study was to evaluate in vitro and in-silicoantiplasmodial potential of Curcuma caesia extracts against Plasmodium falciparum.Methods: Lack of a vaccine and the widespread resistance to antimalarial drugs have resulted in emphasis on novel antimalarial drugs development. Ethyl acetate and methanol extracts of Curcuma caesia were prepared and analysed for their antiplasmodial activity against Chloroquine sensitive (3D7) and resistant (K1) strains of P. falciparumusingfluorescence-based SYBR Green assay. The cytotoxicity tests were carried out using the verocell lines by MTT assay.The phosphoethanolamine methyltransferase enzyme ((PfPMT) essential for growth of Plasmodium falciparum was used as protein target for in-silicostudy.Result: Curcuma caesia ethyl acetate extracts showedpotentantiplasmodial activitywith IC50 values of 3.37 µg/ml and 1.53 µg/ml against 3D7 and K1 strain respectively.Docking results show that β-selinenol an oxygenized sesquiterpene had the free binding energy of -6.76 Kcal/mol.Conclusion: Sesquiterpene present in the Curcuma caesia extract was responsible for antimalarial potential analyzed by molecular modeling. The present findings, however preliminary in nature. Further studies are required to proven the antimalarial efficacy C. caesia by isolating the active compounds and in vivo mechanism study that may contribute to more effective development of antimalarial drugs in the future.

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Discovery of 3-Cinnamamido-N-Substituted Benzamides as Potential Antimalarial Agents

Medicinal Chemistry ◽

10.2174/1573406416666200817160708 ◽

2020 ◽

Vol 16 ◽

Author(s):

Haicheng Liu ◽

Yushi Futamura ◽

Honghai Wu ◽

Aki Ishiyama ◽

Taotao Zhang ◽

...

Keyword(s):

Mammalian Cells ◽

Antimalarial Activity ◽

In Vitro Assays ◽

Compound Library ◽

Antimalarial Agents ◽

Phenotypic Screen ◽

Ic50 Values ◽

Substituted Benzamides

Background: Malaria is one of the most devastating parasitic diseases, yet the discovery of antimalarial agents remains profoundly challenging. Very few new antimalarials have been developed in the past 50 years, while the emergence of drug-resistance continues to appear. Objective: This study focuses on the discovery, design, synthesis, and antimalarial evaluation of 3-cinnamamido-N-substituted benzamides. Method: In this study, a screening of our compound library was carried out against the multidrug-sensitive Plasmodium falciparum 3D7 strain. Derivatives of the hit were designed, synthesized and tested against P. falciparum 3D7 and the in vivo antimalarial activity of the most active compounds was evaluated using the method of Peters’ 4-day suppressive test. Results: The retrieved hit compound 1 containing a 3-cinnamamido-N-substituted benzamide skeleton showed moderate antimalarial activity (IC50 = 1.20 µM) for the first time. A series of derivatives were then synthesized through a simple four-step workflow, and half of them exhibited slightly better antimalarial effect than the precursor 1 during the subsequent in vitro assays. Additionally, compounds 11, 23, 30 and 31 displayed potent activity with IC50 values of approximately 0.1 µM, and weak cytotoxicity against mammalian cells. However, in vivo antimalarial activity is not effective which might be ascribed to the poor solubility of these compounds. Conclusion: In this study, phenotypic screen of our compound library resulted in the first report of 3-cinnamamide framework with antimalarial activity and 40 derivatives were then designed and synthesized. Subsequent structure-activity studies showed that compounds 11, 23, 30 and 31 exhibited the most potent and selective activity against P. falciparum 3D7 strain with IC50 values around 0.1 µM. Our work herein sets another example of phenotypic screen-based drug discovery, leading to potentially promising candidates of novel antimalarial agents once given further optimization.

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Stage-dependent effect of deferoxamine on growth of Plasmodium falciparum in vitro

Blood ◽

10.1182/blood.v76.6.1250.1250 ◽

1990 ◽

Vol 76 (6) ◽

pp. 1250-1255 ◽

Cited By ~ 36

Author(s):

S Whitehead ◽

TE Peto

Keyword(s):

Plasmodium Falciparum ◽

Growth Inhibition ◽

Antimalarial Activity ◽

Clinical Malaria ◽

Inhibitory Effect ◽

Parasite Development ◽

And Control ◽

Speed Of Onset

Abstract Deferoxamine (DF) has antimalarial activity that can be demonstrated in vitro and in vivo. This study is designed to examine the speed of onset and stage dependency of growth inhibition by DF and to determine whether its antimalarial activity is cytostatic or cytocidal. Growth inhibition was assessed by suppression of hypoxanthine incorporation and differences in morphologic appearance between treated and control parasites. Using synchronized in vitro cultures of Plasmodium falciparum, growth inhibition by DF was detected within a single parasite cycle. Ring and nonpigmented trophozoite stages were sensitive to the inhibitory effect of DF but cytostatic antimalarial activity was suggested by evidence of parasite recovery in later cycles. However, profound growth inhibition, with no evidence of subsequent recovery, occurred when pigmented trophozoites and early schizonts were exposed to DF. At this stage in parasite development, the activity of DF was cytocidal and furthermore, the critical period of exposure may be as short as 6 hours. These observations suggest that iron chelators may have a role in the treatment of clinical malaria.

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Antimalarial Effect of the Total Glycosides of the Medicinal Plant, Ranunculus japonicus

Pathogens ◽

10.3390/pathogens10050532 ◽

2021 ◽

Vol 10 (5) ◽

pp. 532

Author(s):

Hae-Soo Yun ◽

Sylvatrie-Danne Dinzouna-Boutamba ◽

Sanghyun Lee ◽

Zin Moon ◽

Dongmi Kwak ◽

...

Keyword(s):

Chinese Medicine ◽

Traditional Chinese Medicine ◽

Plasmodium Berghei ◽

Antimalarial Activity ◽

Hematological Parameters ◽

Significant Inhibition ◽

Ic50 Values ◽

The Republic

In traditional Chinese medicine, Ranunculus japonicus has been used to treat various diseases, including malaria, and the young stem of R. japonicus is consumed as a food in the Republic of Korea. However, experimental evidence of the antimalarial effect of R. japonicus has not been evaluated. Therefore, the antimalarial activity of the extract of the young stem of R. japonicus was evaluated in vitro using both chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strains; in vivo activity was evaluated in Plasmodium berghei-infected mice via oral administration followed by a four-day suppressive test focused on biochemical and hematological parameters. Exposure to extracts of R. japonicus resulted in significant inhibition of both chloroquine-sensitive (3D7) and resistant (Dd2) strains of P. falciparum, with IC50 values of 6.29 ± 2.78 and 5.36 ± 4.93 μg/mL, respectively. Administration of R. japonicus also resulted in potent antimalarial activity against P. berghei in infected mice with no associated toxicity; treatment also resulted in improved hepatic, renal, and hematologic parameters. These results demonstrate the antimalarial effects of R. japonicus both in vitro and in vivo with no apparent toxicity.

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Inside Cover: Docking Studies of Structurally Diverse Antimalarial Drugs Targeting PfATP6: No Correlation between in silico Binding Affinity and in vitro Antimalarial Activity. (ChemMedChem 9/2009)

ChemMedChem ◽

10.1002/cmdc.200990042 ◽

2009 ◽

Vol 4 (9) ◽

pp. 1386-1386

Author(s):

Fatima Bousejra-El Garah ◽

Jean-Luc Stigliani ◽

Frédéric Coslédan ◽

Bernard Meunier ◽

Anne Robert

Keyword(s):

Binding Affinity ◽

In Silico ◽

Antimalarial Activity ◽

Docking Studies ◽

Antimalarial Drugs

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Synthetic spirocyclic endoperoxides: new antimalarial scaffolds

MedChemComm ◽

10.1039/c4md00454j ◽

2015 ◽

Vol 6 (2) ◽

pp. 357-362 ◽

Cited By ~ 31

Author(s):

Margherita Brindisi ◽

Sandra Gemma ◽

Sanil Kunjir ◽

Luisa Di Cerbo ◽

Simone Brogi ◽

...

Keyword(s):

Molecular Docking ◽

Antimalarial Activity ◽

Design Synthesis ◽

Docking Calculation

Design, synthesis and molecular docking calculation studies led to the identification of novel spirocyclic peroxides with in vitro and in vivo antimalarial activity.

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Mammalian deubiquitinating enzyme inhibitors display in vitro and in vivo activity against malaria parasites and potentiate artemisinin action

10.1101/2020.08.13.249425 ◽

2020 ◽

Author(s):

Nelson V. Simwela ◽

Katie R. Hughes ◽

Michael T. Rennie ◽

Michael P. Barrett ◽

Andrew P. Waters

Keyword(s):

Anticancer Agents ◽

Drug Targets ◽

Reverse Genetics ◽

Enzyme Inhibitors ◽

Artemisinin Resistance ◽

Drug Repurposing ◽

Antimalarial Drugs ◽

Malaria Parasites

AbstractCurrent malaria control efforts rely significantly on artemisinin combinational therapies which have played massive roles in alleviating the global burden of the disease. Emergence of resistance to artemisinins is therefore, not just alarming but requires immediate intervention points such as development of new antimalarial drugs or improvement of the current drugs through adjuvant or combination therapies. Artemisinin resistance is primarily conferred by Kelch13 propeller mutations which are phenotypically characterised by generalised growth quiescence, altered haemoglobin trafficking and downstream enhanced activity of the parasite stress pathways through the ubiquitin proteasome system (UPS). Previous work on artemisinin resistance selection in a rodent model of malaria, which we and others have recently validated using reverse genetics, has also shown that mutations in deubiquitinating enzymes, DUBs (upstream UPS component) modulates susceptibility of malaria parasites to both artemisinin and chloroquine. The UPS or upstream protein trafficking pathways have, therefore, been proposed to be not just potential drug targets, but also possible intervention points to overcome artemisinin resistance. Here we report the activity of small molecule inhibitors targeting mammalian DUBs in malaria parasites. We show that generic DUB inhibitors can block intraerythrocytic development of malaria parasites in vitro and possess antiparasitic activity in vivo and can be used in combination with additive effect. We also show that inhibition of these upstream components of the UPS can potentiate the activity of artemisinin in vitro as well as in vivo to the extent that ART resistance can be overcome. Combinations of DUB inhibitors anticipated to target different DUB activities and downstream 20s proteasome inhibitors are even more effective at improving the potency of artemisinins than either inhibitors alone providing proof that targeting multiple UPS activities simultaneously could be an attractive approach to overcoming artemisinin resistance. These data further validate the parasite UPS as a target to both enhance artemisinin action and potentially overcome resistance. Lastly, we confirm that DUB inhibitors can be developed into in vivo antimalarial drugs with promise for activity against all of human malaria and could thus further exploit their current pursuit as anticancer agents in rapid drug repurposing programs.Graphical abstract

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Inhibition of Heme Polymerization Invitro Assay Of Extract of Sirih Leaf (Piper betle Linn.) and Sun Flower Leaves (Helianthus annuus L.)

Indonesian Journal of Pharmaceutical Science and Technology ◽

10.24198/ijpst.v7i1.25319 ◽

2020 ◽

Vol 7 (1) ◽

pp. 22 ◽

Cited By ~ 1

Author(s):

Ami Tjitraresmi ◽

Moelyono Moektiwardoyo ◽

Yasmiwar Susilawati

Keyword(s):

Helianthus Annuus ◽

Antimalarial Activity ◽

Antimalarial Drugs ◽

Piper Betle ◽

Phytochemical Screening ◽

Helianthus Annuus L ◽

Betel Leaf ◽

The People ◽

Ic50 Values

Malaria is a disease that occurs in tropical countries like Indonesia. The incidence of malaria in the world is still quite high and the occurrence of cases of Plasmodium resistance to antimalarial drugs and the widespread of resistance have prompted researchers to look for new antimalarial drugs, especially from natural materials. Betel leaf (Piper betle Linn.) And sunflower leaf (Helianthus annuus L.) have long been used by the people of Indonesia as an antimalarial drug. The purpose of this study was to determine antimalarial activity through inhibition of heme polymerization and determine secondary metabolite compounds by phytochemical screening from betel leaves and sunflower leaves. The heme polymerization inhibition activity assay was carried out by the in-vitro method using a microplate reader at 415 nm and 630 nm wavelengths. IC50 values of betel leaf extract and sunflower leaf were 178.67 μg/ml and 160.10 μg/ml, respectively. Phytochemical screening results from betel leaf showed the presence of flavonoids, polyphenols, tannins, quinones, saponins, and monoterpenoids-sesquiterpenoids, while sunflower leaves contain alkaloids, polyphenols, flavonoids, steroids and monoterpenoids-sesquiterpenoids.Keywords: Piper betle Linn., Helianthus annuus L., Malaria, Heme Polymerization

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