scholarly journals Plant-derived antimalarial agents: new leads and efficient phythomedicines. Part I. Alkaloids

2009 ◽  
Vol 81 (4) ◽  
pp. 715-740 ◽  
Author(s):  
Alaíde B. Oliveira ◽  
Maria Fâni Dolabela ◽  
Fernão C. Braga ◽  
Rose L.R.P. Jácome ◽  
Fernando P. Varotti ◽  
...  

Malaria remains one of the most serious world health problem and the major cause of mortality and morbidity in the endemic regions. Brazil is among the 30 high-burden countries and most of the cases occur in the Legal Amazonian Region. New chemotherapeutical agents are needed for the treatment of malaria. Many plant species are used in traditional medicines of malarious countries and a relatively few number of these have been investigated for evaluation of their antimalarial effect. Still lower is the number of those that have had the active natural compounds isolated and the toxicity determined. This area is, then, of great research interest. discovery project of antimalarial natural products from plants traditionally used to treat malaria must include in vitro and in vivo assays as well as bioguided isolation of active compounds. The final products would be antimalarial chemical entities, potential new drugs or templates for new drugs development, and/or standardized antimalarial extracts which are required for pre-clinical and clinical studies when the aim is the development of effective and safe phythomedicines. This review discusses these two approaches, presents briefly the screening methodologies for evaluation of antimalarial activity and focuses the activity of alkaloids belonging to different structural classes as well as its importance as new antimalarial drugs or leads and chemical markers for phytomedicines.

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Dejen Nureye ◽  
Solomon Assefa ◽  
Teshome Nedi ◽  
Ephrem Engidawork

Background. Evolution of antimalarial drug resistance makes the development of new drugs a necessity. Important source in search of such drugs is medicinal plants.Gardenia ternifoliaplant is used in Ethiopian traditional medicine for the treatment of malaria and is endowed within vitroantimalarial activity. Herein, thein vivoantimalarial activity of the plant was investigated.Methods. Acute toxicity was carried out using a standard procedure. A 4-day suppressive test was employed to evaluate the antimalarial effect of methanolic crude extract and solvent fractions of the plant. The curative and prophylactic effect of crude extract was further tested by Ranes’s test and residual infection procedure, respectively, usingPlasmodium berghei(ANKA strain) in Swiss albino mice.Results. The chemosuppressive effect exerted by the crude extract and fractions ranged between 30-59% and 14-51%, respectively. Curative and prophylactic effects of the crude extract were in the range of 36-63% and 24-37%, respectively. All dose levels of the crude extract prevented loss of weight, reduction in temperature, and anemia on early and established infection. Butanol and chloroform fractions also did reverse reduction in temperature, body weight, and packed cell volume.Conclusions. The results indicated that the plant has a promising antiplasmodial activity and it could be considered as a potential source to develop new antimalarial agents.


2018 ◽  
Vol 24 (10) ◽  
pp. 1138-1147
Author(s):  
Bruno Rivas-Santiago ◽  
Flor Torres-Juarez

Tuberculosis is an ancient disease that has become a serious public health issue in recent years, although increasing incidence has been controlled, deaths caused by Mycobacterium tuberculosis have been accentuated due to the emerging of multi-drug resistant strains and the comorbidity with diabetes mellitus and HIV. This situation is threatening the goals of World Health Organization (WHO) to eradicate tuberculosis in 2035. WHO has called for the creation of new drugs as an alternative for the treatment of pulmonary tuberculosis, among the plausible molecules that can be used are the Antimicrobial Peptides (AMPs). These peptides have demonstrated remarkable efficacy to kill mycobacteria in vitro and in vivo in experimental models, nevertheless, these peptides not only have antimicrobial activity but also have a wide variety of functions such as angiogenesis, wound healing, immunomodulation and other well-described roles into the human physiology. Therapeutic strategies for tuberculosis using AMPs must be well thought prior to their clinical use; evaluating comorbidities, family history and risk factors to other diseases, since the wide function of AMPs, they could lead to collateral undesirable effects.


2020 ◽  
Vol 16 ◽  
Author(s):  
Haicheng Liu ◽  
Yushi Futamura ◽  
Honghai Wu ◽  
Aki Ishiyama ◽  
Taotao Zhang ◽  
...  

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.


2019 ◽  
Vol 24 ◽  
pp. 2515690X1988532 ◽  
Author(s):  
Dagninet Derebe ◽  
Muluken Wubetu

Failure of the efficacy of antimalarial drugs is recognized in different classes of medicines for treating malaria, which urges the need for new drugs. This study tried to check the in vivo antimalarial activity of the root extracts of Acanthus polystachyus Delile against Plasmodium berghei–infected mice. The study revealed that the methanolic crude extract of the root of Acanthus polystachyus Delile showed significant ( P < .01) parasitemia suppressive activities in both models compared with the negative control. Parasitemia suppressive activities were 25.26%, 33.46%, and 51.48% in a 4-day suppressive test and 23.31%, 31.20%, and 43.54% in prophylaxis test at 100, 200, and 400 mg/kg of the extract, respectively, as compared to the negative control. Besides, the extract increases mean survival time significantly in all tested doses in a 4-day suppressive test, but in the prophylaxis model, only mice treated with 200 and 400 mg/kg significantly lived longer. Based on this finding, the root of Acanthus polystachyus Delile has strong antimalarial activity, which may be a good candidate for new antimalarial agents.


2009 ◽  
Vol 53 (4) ◽  
pp. 1320-1324 ◽  
Author(s):  
M. O. Faruk Khan ◽  
Mark S. Levi ◽  
Babu L. Tekwani ◽  
Shabana I. Khan ◽  
Eiichi Kimura ◽  
...  

ABSTRACT In an attempt to augment the efficacy of 7-chloro 4-aminoquinoline analogs and also to overcome resistance to antimalarial agents, we synthesized three cyclen (1,4,7,10-tetraazacyclododecane) analogs of chloroquine [a bisquinoline derivative, 7-chloro-4-(1,4,7,10-tetraaza-cyclododec-1-yl)-quinoline HBr, and a 7-chloro-4-(1,4,7,10-tetraaza-cyclododec-1-yl)-quinoline-Zn2+ complex]. The bisquinoline displays the most potent in vitro and in vivo antimalarial activities. It displays 50% inhibitory concentrations (IC50s) of 7.5 nM against the D6 (chloroquine-sensitive) clone of Plasmodium falciparum and 19.2 nM against the W2 (chloroquine-resistant) clone, which are comparable to those of artemisinin (10.6 and 5.0 nM, respectively) and lower than those of chloroquine (10.7 and 87.2 nM, respectively), without any evidence of cytotoxicity to mammalian cells, indicating a high selectivity index (>1,333 against D6 clone and >521 against W2 clone). Potent antimalarial activities of the bisquinoline against chloroquine- and mefloquine-resistant strains of P. falciparum were also confirmed by in vitro [3H]hypoxanthine incorporation assay. The in vivo antimalarial activity of the bisquinoline, as determined in P. berghei-infected mice, is comparable to that of chloroquine (50% effective dose, ≤1.1 mg/kg when given orally); no apparent toxicity has been observed up to the highest dose tested (3 × 30 mg/kg). The bisquinoline inhibits in vitro hemozoin (β-hematin) formation with an IC50 of 1.1 μM, which is about 10-fold more potent than chloroquine (IC50 9.5 μM). Overall, this article describes the discovery of a new class of cyclen 4-aminoquinoline analogs as potent antimalarial drugs.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
M. O. Falade ◽  
D. O. Akinboye ◽  
G. O. Gbotosho ◽  
E. O. Ajaiyeoba ◽  
T. C. Happi ◽  
...  

Drug resistance inPlasmodium falciparumrequires that new drugs must be developed. Plants are a potential source for drug discovery and development. Two plants that used to treat febrile illnesses in Nigeria were tested forin vitroandin vivoantimalarial activity and cytotoxicity in cancer cell lines. Methanol, hexane, and ethyl acetate leaf extracts ofFicus thonningiiandLophira alatawere active inin vitroassays againstP. falciparumNF54 (sensitive) and K1 (multiresistant) strains. Hexane extracts ofF. thonningiiandL. alatawere the most effective extracts inin vitroassays with IC50of2.7±1.6 μg/mL and2.5±0.3 μg/mL for NF54 and10.4±1.6 μg/mL and2.5±2.1 μg/mL for K1 strain. All extracts were nontoxic in cytotoxicity assays against KB human cell line with IC50of over 20 μg/mL, demonstrating selectivity againstP. falciparum.In vivoanalysis shows that hexane extracts of both plants reduced parasitaemia. At the maximum dose tested,L. alatahad a 74.4% reduction of parasitaemia whileF. thonningiihad a reduction of 84.5%, both extracts prolonged animal survival in mice infected withP. bergheiNK65 when compared with vehicle treated controls. The antiplasmodial activity observed justifies the use of both plants in treating febrile conditions.


Author(s):  
Naseer Ahmed

Abstract Cardioprotection is a very challenging area in the field of cardiovascular sciences. Myocardial damage accounts for nearly 50% of injury due to reperfusion, yet there is no effective strategy to prevent this to reduce the burden of heart failure. During last couple of decades, by combining genetic and bimolecular studies, many new drugs have been developed to treat hypertension, heart failure, and cancer. The use of percutaneous coronary intervention has reduced the mortality and morbidity of acute coronary syndrome dramatically. However, there is no standard therapy available that can mitigate cardiac reperfusion injury, which contributes to up to half of myocardial infarcts. Literature shows that the activation of sphingosine receptors, which are G protein-coupled receptors, induces cardioprotection both in vitro and in vivo. The exact mechanism of this protection is not clear yet. In this review, we discuss the mechanism of ischemia reperfusion injury and the role of the FDA-approved sphingosine 1 phosphate drug fingolimod in cardioprotection.


2020 ◽  
Author(s):  
Awet Alem Teklemichael ◽  
Shusaku Mizukami ◽  
Kazufumi Toume ◽  
Farhana Mosaddeque ◽  
Mohamed Gomaa Kamel ◽  
...  

Abstract Background: The herbal medicine has been a rich source of new drugs exemplified by quinine and artemisinin. In this study, 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 herbal extracts (n = 120) and related compounds (n=96). 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. After being selected through the first in vitro assay, positive extracts and compounds were examined for possible in vivo antimalarial activity. Results: Out of 120 herbal extracts, Coptis Rhizome showed the highest antimalarial activity (IC 50 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 chlorinated compounds (coptisine, berberine, and palmatine) related to Coptis Rhizome also showed antimalarial activities with IC 50 1.1, 2.6, and 6.0 µM (against 3D7) and 3.1, 6.3, and 11.8 µM (against Dd2), respectively. Among them, coptisine chloride exhibited the highest antimalarial activity (IC 50 1.1 µM against 3D7 and 3.1 µM against Dd2) with SI of 37.8 and 13.2, respectively. . Finally, the herbal extract of Coptis Rhizome and its major active compound coptisine chloride exhibited significant antimalarial activity in mice infected with P. yoelii 17X strain with respect to its activity on parasite suppression consistently from day 3 to day 7 post-challenge. The effect ranged from 50.38 to 72.13% (P <.05) for Coptis Rhizome and from 81 to 89% (P <.01) for coptisine chloride. Conclusion: Coptis Rhizome and its major active compound coptisine chloride showed promising antimalarial activity against chloroquine-sensitive (3D7) and -resistant (Dd2) strains in vitro as well as in vivo mouse malaria model. Thus Kampo herbal medicine is a potential natural resource for novel antipathogenic agents.


2018 ◽  
Vol 18 (2) ◽  
pp. 114-123 ◽  
Author(s):  
Xin-Liang Hu ◽  
Chuan Gao ◽  
Zhi Xu ◽  
Ming-Liang Liu ◽  
Lian-Shun Feng ◽  
...  

Malaria still remains one of the leading deadliest diseases throughout the world, leading to around 1 million deaths annually. The emergence and spread of growing resistance to the firstline antimalarials are an alarming the serious problem in malaria control, demanding the need for new drugs more potent than earlier with improved Absorption, Distribution, Metabolism, and Excretion (ADME) profiles. Coumarins, which exhibited various biological properties, also displayed potential in vitro antiplasmodial and in vivo antimalarial activities. Moreover, many of coumarin derivatives have already been used in clinical practice for the treatment of several diseases. Therefore, coumarin derivatives play a pivotal role in medicinal chemistry, also making them promising candidates for the treatment of malaria. This review aims to summarize the recent advances made towards the development of coumarin-containing derivatives as antiplasmodial and antimalarial agents and their structure-activity relationship is also discussed.


2019 ◽  
Vol 15 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Fady N. Akladios ◽  
Scott D. Andrew ◽  
Samantha J. Boog ◽  
Carmen de Kock ◽  
Richard K. Haynes ◽  
...  

Background:The emergence of resistance to the artemisinins which are the current mainstays for antimalarial chemotheraphy has created an environment where the development of new drugs acting in a mechanistally discrete manner is a priority.Objective:The goal of this work was to synthesize ane evaluate bis-thiosemicarbazones as potential antimalarial agents. </P><P> Methods: Fifteen compounds were generated using two condensation protocols and evaluated in vitro against the NF54 (CQ sensitive) strain of Plasmodium falciparum. A preliminary assessment of the potential for human toxicity was conducted in vitro against the MRC5 human lung fibroblast line.Results:The activity of the bis-thiosemicarbazones was highly dependent on the nature of the arene at the core of the structure. The inclusion of a non-coordinating benzene core resulted in inactive compounds, while the inclusion of a pyridyl core resulted in compounds of moderate or potent antimalarial activity (4 compounds showing IC50 < 250 nM).Conclusion:Bis-thiosemicarbazones containing a central pyridyl core display potent antimalarial activity in vitro. Sequestration and activation of ferric iron appears to play a significant role in this activity. Ongoing studies are aimed at further development of this series as potential antimalarials.


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