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1.
Int J Parasitol Drugs Drug Resist ; 25: 100533, 2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38555795

ABSTRACT

Animal trypanosomiasis (AT) is a complex of veterinary diseases known under various names such as nagana, surra, dourine and mal de caderas, depending on the country, the infecting trypanosome species and the host. AT is caused by parasites of the genus Trypanosoma, and the main species infecting domesticated animals are T. brucei brucei, T. b. rhodesiense, T. congolense, T. simiae, T. vivax, T. evansi and T. equiperdum. AT transmission, again depending on species, is through tsetse flies or common Stomoxys and tabanid flies or through copulation. Therefore, the geographical spread of all forms of AT together is not restricted to the habitat of a single vector like the tsetse fly and currently includes almost all of Africa, and most of South America and Asia. The disease is a threat to millions of companion and farm animals in these regions, creating a financial burden in the billions of dollars to developing economies as well as serious impacts on livestock rearing and food production. Despite the scale of these impacts, control of AT is neglected and under-resourced, with diagnosis and treatments being woefully inadequate and not improving for decades. As a result, neither the incidence of the disease, nor the effectiveness of treatment is documented in most endemic countries, although it is clear that there are serious issues of resistance to the few old drugs that are available. In this review we particularly look at the drugs, their application to the various forms of AT, and their mechanisms of action and resistance. We also discuss the spread of veterinary trypanocide resistance and its drivers, and highlight current and future strategies to combat it.

2.
J Med Chem ; 66(19): 13452-13480, 2023 10 12.
Article in English | MEDLINE | ID: mdl-37729094

ABSTRACT

The AT-rich mitochondrial DNA (kDNA) of trypanosomatid parasites is a target of DNA minor groove binders. We report the synthesis, antiprotozoal screening, and SAR studies of three series of analogues of the known antiprotozoal kDNA binder 2-((4-(4-((4,5-dihydro-1H-imidazol-3-ium-2-yl)amino)benzamido)phenyl)amino)-4,5-dihydro-1H-imidazol-3-ium (1a). Bis(2-aminoimidazolines) (1) and bis(2-aminobenzimidazoles) (2) showed micromolar range activity against Trypanosoma brucei, whereas bisarylimidamides (3) were submicromolar inhibitors of T. brucei, Trypanosoma cruzi, and Leishmania donovani. None of the compounds showed relevant activity against the urogenital, nonkinetoplastid parasite Trichomonas vaginalis. We show that series 1 and 3 bind strongly and selectively to the minor groove of AT DNA, whereas series 2 also binds by intercalation. The measured pKa indicated different ionization states at pH 7.4, which correlated with the DNA binding affinities (ΔTm) for series 2 and 3. Compound 3a, which was active and selective against the three parasites and displayed adequate metabolic stability, is a fine candidate for in vivo studies.


Subject(s)
Antiprotozoal Agents , Benzamides , Leishmania donovani , Parasites , Trypanosoma brucei brucei , Trypanosoma cruzi , Animals , Antiprotozoal Agents/chemistry , DNA/metabolism , DNA, Kinetoplast/metabolism , Imidazoles/chemistry , Imidazoles/pharmacology , Leishmania donovani/metabolism , Parasites/drug effects , Parasites/metabolism , Benzamides/chemistry , Benzamides/pharmacology
3.
Int J Mol Sci ; 24(4)2023 Feb 05.
Article in English | MEDLINE | ID: mdl-36834557

ABSTRACT

African Animal Trypanosomiasis (AAT), caused predominantly by Trypanosoma brucei brucei, T. vivax and T. congolense, is a fatal livestock disease throughout Sub-Saharan Africa. Treatment options are very limited and threatened by resistance. Tubercidin (7-deazaadenosine) analogs have shown activity against individual parasites but viable chemotherapy must be active against all three species. Divergence in sensitivity to nucleoside antimetabolites could be caused by differences in nucleoside transporters. Having previously characterized the T. brucei nucleoside carriers, we here report the functional expression and characterization of the main adenosine transporters of T. vivax (TvxNT3) and T. congolense (TcoAT1/NT10), in a Leishmania mexicana cell line ('SUPKO') lacking adenosine uptake. Both carriers were similar to the T. brucei P1-type transporters and bind adenosine mostly through interactions with N3, N7 and 3'-OH. Expression of TvxNT3 and TcoAT1 sensitized SUPKO cells to various 7-substituted tubercidins and other nucleoside analogs although tubercidin itself is a poor substrate for P1-type transporters. Individual nucleoside EC50s were similar for T. b. brucei, T. congolense, T. evansi and T. equiperdum but correlated less well with T. vivax. However, multiple nucleosides including 7-halogentubercidines displayed pEC50>7 for all species and, based on transporter and anti-parasite SAR analyses, we conclude that nucleoside chemotherapy for AAT is viable.


Subject(s)
Trypanosoma congolense , Trypanosomiasis, African , Animals , Trypanosomiasis, African/parasitology , Nucleosides/therapeutic use , Tubercidin/therapeutic use , Adenosine/therapeutic use , Cloning, Molecular
4.
Molecules ; 28(2)2023 Jan 07.
Article in English | MEDLINE | ID: mdl-36677679

ABSTRACT

Propolis is a resin that is gathered by bees from exudates produced by various plants. Its exact chemical composition depends on the plants available near the hive. Bees use propolis to coat the surfaces of the hive, where it acts as an anti-infective. Regardless of the chemical composition of propolis, it is always anti-protozoal, probably because protozoan parasites, particularly Lotmarium passim, are widespread in bee populations. The protozoa Trypanosoma brucei and T. congolense cause disease in humans and/or animals. The existing drugs for treating these diseases are old and resistance is an increasingly severe problem. The many types of propolis present a rich source of anti-trypanosomal compounds-from a material gathered by bees in an environmentally friendly way. In the current work, red Nigerian propolis from Rivers State, Nigeria was tested against T. brucei and T. congolense and found to be highly active (EC50 1.66 and 4.00 µg/mL, respectively). Four isoflavonoids, vestitol, neovestitol, 7-methylvestitol and medicarpin, were isolated from the propolis. The isolated compounds were also tested against T. brucei and T. congolense, and vestitol displayed the highest activity at 3.86 and 4.36 µg/mL, respectively. Activities against drug-resistant forms of T. brucei and T. congolense were similar to those against wild type.


Subject(s)
Anti-Infective Agents , Propolis , Trypanosoma brucei brucei , Trypanosoma congolense , Trypanosomiasis, African , Humans , Animals , Propolis/pharmacology , Propolis/chemistry , Nigeria , Trypanosomiasis, African/drug therapy
5.
Toxicon ; 224: 107035, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36706926

ABSTRACT

The World Health Organization has listed Snakebite Envenoming (SBE) as a priority neglected tropical disease, with a worldwide annual snakebite affecting 5.4 million people and injuring 2.7 million lives. In many parts of rural areas of Africa and Asia, medicinal plants have been used as alternatives to conventional antisnake venom (ASV) due in part to inaccessibility to hospitals. Systemic reviews (SR) of laboratory-based preclinical studies play an essential role in drug discovery. We conducted an SR to evaluate the relationship between interventional medicinal plants and their observed effects on venom-induced experiments. This SR was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The Modified collaborative approach to meta-analysis and review of animal data from experimental studies (CAMARADES) and SYRCLE's risk of bias tools were used to appraise the included studies. Data were searched online in Medline via PubMed, Embase via OVID, and Scopus. Studies reporting in vivo and in vitro pharmacological activities of African medicinal plants/extracts/constituents against venom-induced pathologies were identified and included for screening. Data from the included studies were extracted and synthesized. Ten studies reported statistically significant percentage protection (40-100%) of animals against venom-induced lethality compared with control groups that received no medicinal plant intervention. Sixteen studies reported significant effects (p ≤ 0.05) against venom-induced pathologies compared with the control group; these include hemolytic, histopathologic, necrotic, and anti-enzymatic effects. The plant family Fabaceae has the highest number of studies reporting its efficacy, followed by Annonaceae, Malvaceae, Combretaceae, Sterculiaceae, and Olacaceae. Some African medicinal plants are preclinically effective against venom-induced lethality, hematotoxicity, and cytotoxicity. The evidence was extracted from three in vitro studies, nine in vivo studies, and five studies that combined both in vivo and in vitro models. The effective plants belong to the Fabaceae family, followed by Malvaceae, and Annonaceae.


Subject(s)
Plants, Medicinal , Snake Bites , Animals , Africa , Antivenins/therapeutic use , Asia , Snake Bites/drug therapy , Treatment Outcome
6.
Article in English | MEDLINE | ID: mdl-35567803

ABSTRACT

Animal trypanosomiasis (AT) is a parasitic disease with high socio-economic impact. Given the limited therapeutic options and problems of toxicity and drug resistance, this study assessed redirecting our previously identified antitrypanosomal nucleosides for the treatment of AT. Promising hits were identified with excellent in vitro activity across all important animal trypanosome species. Compound 7, an inosine analogue, and our previously described lead compound, 3'-deoxytubercidin (8), showed broad spectrum anti-AT activity, metabolic stability in the target host species and absence of toxicity, but with variable efficacy ranging from limited activity to full cure in mouse models of Trypanosoma congolense and T. vivax infection. Several compounds show promise against T. evansi (surra) and T. equiperdum (dourine). Given the preferred target product profile for a broad-spectrum compound against AT, this study emphasizes the need to include T. vivax in the screening cascade given its divergent susceptibility profile and provides a basis for lead optimization towards such broad spectrum anti-AT compound.


Subject(s)
Trypanosoma congolense , Trypanosoma , Trypanosomiasis , Animals , Disease Models, Animal , Drug Resistance , Mice , Nucleosides/therapeutic use , Trypanosomiasis/drug therapy , Trypanosomiasis/parasitology
7.
Molecules ; 27(5)2022 Mar 01.
Article in English | MEDLINE | ID: mdl-35268726

ABSTRACT

Profiling a propolis sample from Papua New Guinea (PNG) using high-resolution mass spectrometry indicated that it contained several triterpenoids. Further fractionation by column chromatography and medium-pressure liquid chromatography (MPLC) followed by nuclear magnetic resonance spectroscopy (NMR) identified 12 triterpenoids. Five of these were obtained pure and the others as mixtures of two or three compounds. The compounds identified were: mangiferonic acid, ambonic acid, isomangiferolic acid, ambolic acid, 27-hydroxyisomangiferolic acid, cycloartenol, cycloeucalenol, 24-methylenecycloartenol, 20-hydroxybetulin, betulin, betulinic acid and madecassic acid. The fractions from the propolis and the purified compounds were tested in vitro against Crithidia fasciculata, Trypanosoma congolense, drug-resistant Trypanosoma congolense, Trypanosoma b. brucei and multidrug-resistant Trypanosoma b. brucei (B48). They were also assayed for their toxicity against U947 cells. The compounds and fractions displayed moderate to high activity against parasitic protozoa but only low cytotoxicity against the mammalian cells. The most active isolated compound, 20-hydroxybetulin, was found to be trypanostatic when different concentrations were tested against T. b. brucei growth.


Subject(s)
Propolis
8.
Int J Mol Sci ; 23(5)2022 Mar 05.
Article in English | MEDLINE | ID: mdl-35269985

ABSTRACT

The animal trypanosomiases are infections in a wide range of (domesticated) animals with any species of African trypanosome, such as Trypanosoma brucei, T. evansi, T. congolense, T. equiperdum and T. vivax. Symptoms differ between host and infective species and stage of infection and are treated with a small set of decades-old trypanocides. A complication is that not all trypanosome species are equally sensitive to all drugs and the reasons are at best partially understood. Here, we investigate whether drug transporters, mostly identified in T. b. brucei, determine the different drug sensitivities. We report that homologues of the aminopurine transporter TbAT1 and the aquaporin TbAQP2 are absent in T. congolense, while their introduction greatly sensitises this species to diamidine (pentamidine, diminazene) and melaminophenyl (melarsomine) drugs. Accumulation of these drugs in the transgenic lines was much more rapid. T. congolense is also inherently less sensitive to suramin than T. brucei, despite accumulating it faster. Expression of a proposed suramin transporter, located in T. brucei lysosomes, in T. congolense, did not alter its suramin sensitivity. We conclude that for several of the most important classes of trypanocides the presence of specific transporters, rather than drug targets, is the determining factor of drug efficacy.


Subject(s)
Arsenicals , Trypanocidal Agents , Trypanosoma congolense , Trypanosoma , Animals , Membrane Transport Proteins , Pentamidine/metabolism , Pentamidine/pharmacology , Suramin/pharmacology , Trypanocidal Agents/pharmacology , Trypanosoma congolense/metabolism
9.
Ther Adv Infect Dis ; 9: 20499361211072644, 2022.
Article in English | MEDLINE | ID: mdl-35237433

ABSTRACT

BACKGROUND: Snakebite envenoming (SBE) is a high-priority, neglected, tropical disease that affects millions of people in developing countries annually. The only available standard drug used for the treatment of SBE is antisnake venom (ASV) which consists of immunoglobulins that have been purified from the plasma of animals hyper-immunized against snake venoms. The use of plants as alternatives for treatment of poisonous bites particularly snakebites is important in remote areas where there might be limited, or no access to hospitals and storage facilities for antivenom. The pharmacological activity of some of the medicinal plants used traditionally in the treatment of SBE have also been scientifically validated. METHOD: A systematic review will be conducted according to the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies checklist for study quality in animal/in vivo studies. The tool will be modified and validated to assess in vitro models and studies that combine in vivo and in vitro studies. The systematic review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. English published articles on African medicinal plants used in the treatment of snakebite envenoming will be searched in Medline, Embase, and Scopus from 2000 to 2021. DISSEMINATION: The findings of the study will be communicated through publication in peer-reviewed journal and presentation at scientific conferences. Medicinal plants have been important sources for the development of many effective drugs currently available in orthodox medicine. Botanically derived medicines have played a major role in human societies throughout history. Plants components used in traditional medicine gained much attention by many toxinologists as a tool for designing potent antidotes against snake envenoming. Our systematic review will provide a synthesis of the literature on the efficacy of these medicinal plants. We will also appraise the prospects of African medicinal plants with pharmacologically demonstrated activity against snakebite and envenoming.

10.
ACS Med Chem Lett ; 13(2): 312-318, 2022 Feb 10.
Article in English | MEDLINE | ID: mdl-35178188

ABSTRACT

The trypanosome alternative oxidase (TAO), a mitochondrial enzyme involved in the respiration of the bloodstream form trypomastigotes of Trypanosoma brucei, is a validated drug target against African trypanosomes. Earlier series of TAO inhibitors having a 2,4-dihydroxy-6-methylbenzoic acid scaffold ("head") and a triphenylphosphonium or quinolin-1-ium cation as a mitochondrion-targeting group ("tail") were shown to be nanomolar inhibitors in enzymatic and cellular assays. We investigated here the effect of different mitochondrion-targeting cations and other scaffold modifications on the in vitro activity of this class of inhibitors. Low micromolar range activities were obtained, and the structure-activity relationship studies showed that modulation of the tail region with polar substituents is generally detrimental to the enzymatic and cellular activity of TAO inhibitors.

11.
ChemMedChem ; 16(22): 3396-3401, 2021 11 19.
Article in English | MEDLINE | ID: mdl-34357687

ABSTRACT

A selective mono-N-arylation strategy of amidines under Chan-Lam conditions is described. During the reaction optimization phase, the isolation of a mononuclear Cu(II) complex provided unique mechanistic insight into the operation of Chan-Lam mono-N-arylation. The scope of the process is demonstrated, and then applied to access the first mono-N-arylated analogues of pentamidine. Sub-micromolar activity against kinetoplastid parasites was observed for several analogues with no cross-resistance in pentamidine and diminazene-resistant trypanosome strains and against Leishmania mexicana. A fluorescent mono-N-arylated pentamidine analogue revealed rapid cellular uptake, accumulating in parasite nuclei and the kinetoplasts. The DNA binding capability of the mono-N-arylated pentamidine series was confirmed by UV-melt measurements using AT-rich DNA. This work highlights the potential to use Chan-Lam mono-N-arylation to develop therapeutic leads against diamidine-resistant trypanosomiasis and leishmaniasis.


Subject(s)
Amidines/pharmacology , Antiparasitic Agents/pharmacology , Drug Development , Leishmania mexicana/drug effects , Pentamidine/pharmacology , Amidines/chemistry , Antiparasitic Agents/chemical synthesis , Antiparasitic Agents/chemistry , Dose-Response Relationship, Drug , Drug Resistance/drug effects , Molecular Structure , Parasitic Sensitivity Tests , Pentamidine/chemical synthesis , Pentamidine/chemistry , Structure-Activity Relationship
12.
Front Chem ; 9: 624741, 2021.
Article in English | MEDLINE | ID: mdl-33968894

ABSTRACT

The powdered roots of the medicinal plant Acacia nilotica were extracted with hexane and ethyl acetate, and the extracts were subjected to column chromatography for the isolation of potentially bioactive compounds and their screening against kinetoplastid pathogens. NMR and HREI mass spectrometric analyses identified two new diterpenes, characterized as 16, 19-dihydroxycassa-12-en-15-one (Sandynone, 1) and (5S, 7R, 8R, 9R, 10S, 13Z, 17S)-7,8:7,17:16,17-triepoxy-7,8-seco-cassa-13-ene (niloticane B, 2). The previously reported (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-diene-7,17-diol (3), (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-dien-7-ol-17-al (4), and (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-dien-7-ol (5) a, mixture of stigmasterol (6a) and sitosterol (6b), and lupeol (7) were also isolated. Several column fractions displayed significant activity against a panel of Trypanosoma and Leishmania spp., and from the most active fraction, compound 4 was isolated with high purity. The compound displayed high activity, particularly against T. brucei, T. evansi, and L. mexicana (0.88-11.7 µM) but only a modest effect against human embryonic kidney cells and no cross-resistance with the commonly used melaminophenyl arsenical and diamidine classes of trypanocides. The effect of compound 4 against L. mexicana promastigotes was irreversible after a 5-h exposure, leading to the sterilization of the culture between 24 and 48 h.

13.
Eur J Med Chem ; 220: 113470, 2021 Aug 05.
Article in English | MEDLINE | ID: mdl-33940464

ABSTRACT

We have recently reported on the development and trypanocidal activity of a class of inhibitors of Trypanosome Alternative Oxidase (TAO) that are targeted to the mitochondrial matrix by coupling to lipophilic cations via C14 linkers to enable optimal interaction with the enzyme's active site. This strategy resulted in a much-enhanced anti-parasite effect, which we ascribed to the greater accumulation of the compound at the location of the target protein, i.e. the mitochondrion, but to date this localization has not been formally established. We therefore synthesized a series of fluorescent analogues to visualize accumulation and distribution within the cell. The fluorophore chosen, julolidine, has the remarkable extra feature of being able to function as a viscosity sensor and might thus additionally act as a probe of the cellular glycerol that is expected to be produced when TAO is inhibited. Two series of fluorescent inhibitor conjugates incorporating a cationic julolidine-based viscosity sensor were synthesized and their photophysical and biological properties were studied. These probes display a red emission, with a high signal-to-noise ratio (SNR), using both single- and two-photon excitation. Upon incubation with T. brucei and mammalian cells, the fluorescent inhibitors 1a and 2a were taken up selectively in the mitochondria as shown by live-cell imaging. Efficient partition of 1a in functional isolated (rat liver) mitochondria was estimated to 66 ± 20% of the total. The compounds inhibited recombinant TAO enzyme in the submicromolar (1a, 2c, 2d) to low nanomolar range (2a) and were effective against WT and multidrug-resistant trypanosome strains (B48, AQP1-3 KO) in the submicromolar range. Good selectivity (SI > 29) over mammalian HEK cells was observed. However, no viscosity-related shift could be detected, presumably because the glycerol was produced cytosolically, and released through aquaglyceroporins, whereas the probe was located, virtually exclusively, in the trypanosome's mitochondrion.


Subject(s)
Enzyme Inhibitors/pharmacology , Fluorescent Dyes/pharmacology , Mitochondrial Proteins/antagonists & inhibitors , Oxidoreductases/antagonists & inhibitors , Plant Proteins/antagonists & inhibitors , Trypanosoma brucei brucei/drug effects , Trypanosoma/drug effects , Cell Survival/drug effects , Cells, Cultured , Density Functional Theory , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/chemistry , HEK293 Cells , Humans , Microscopy, Fluorescence , Mitochondrial Proteins/metabolism , Molecular Structure , Optical Imaging , Oxidoreductases/metabolism , Plant Proteins/metabolism , Structure-Activity Relationship , Trypanosoma/enzymology , Trypanosoma brucei brucei/enzymology
14.
Mol Microbiol ; 116(2): 564-588, 2021 08.
Article in English | MEDLINE | ID: mdl-33932053

ABSTRACT

Trypanosoma congolense is a principal agent causing livestock trypanosomiasis in Africa, costing developing economies billions of dollars and undermining food security. Only the diamidine diminazene and the phenanthridine isometamidium are regularly used, and resistance is widespread but poorly understood. We induced stable diminazene resistance in T. congolense strain IL3000 in vitro. There was no cross-resistance with the phenanthridine drugs, melaminophenyl arsenicals, oxaborole trypanocides, or with diamidine trypanocides, except the close analogs DB829 and DB75. Fluorescence microscopy showed that accumulation of DB75 was inhibited by folate. Uptake of [3 H]-diminazene was slow with low affinity and partly but reciprocally inhibited by folate and by competing diamidines. Expression of T. congolense folate transporters in diminazene-resistant Trypanosoma brucei brucei significantly sensitized the cells to diminazene and DB829, but not to oxaborole AN7973. However, [3 H]-diminazene transport studies, whole-genome sequencing, and RNA-seq found no major changes in diminazene uptake, folate transporter sequence, or expression. Instead, all resistant clones displayed a moderate reduction in the mitochondrial membrane potential Ψm. We conclude that diminazene uptake in T. congolense proceed via multiple low affinity mechanisms including folate transporters; while resistance is associated with a reduction in Ψm it is unclear whether this is the primary cause of the resistance.


Subject(s)
Diminazene/pharmacology , Membrane Potential, Mitochondrial/physiology , Trypanocidal Agents/pharmacology , Trypanosoma congolense/drug effects , Trypanosomiasis, African/veterinary , Trypanosomiasis, Bovine/drug therapy , Animals , Cattle , Drug Resistance/physiology , Folic Acid Transporters/metabolism , Phenanthridines/pharmacology , Trypanosomiasis, African/drug therapy , Trypanosomiasis, African/parasitology , Trypanosomiasis, Bovine/parasitology
15.
Pathogens ; 10(2)2021 Feb 05.
Article in English | MEDLINE | ID: mdl-33562567

ABSTRACT

Trypanosomiasis and leishmaniasis are a group of neglected parasitic diseases caused by several species of parasites belonging to the family Trypansomatida. The present study investigated the antitrypanosomal and antileishmanial activity of chalcones and flavanones from Polygonum salicifolium, which grows in the wetlands of Iraq. The phytochemical evaluation of the plant yielded two chalcones, 2',4'-dimethoxy-6'-hydroxychalcone and 2',5'-dimethoxy-4',6'-dihydroxychalcone, and two flavanones, 5,7-dimethoxyflavanone and 5,8-dimethoxy-7-hydroxyflavanone. The chalcones showed a good antitrypanosomal and antileishmanial activity while the flavanones were inactive. The EC50 values for 2',4'-dimethoxy-6'-hydroxychalcone against Trypanosoma brucei brucei (0.5 µg/mL), T. congolense (2.5 µg/mL), and Leishmania mexicana (5.2 µg/mL) indicated it was the most active of the compounds. None of the compounds displayed any toxicity against a human cell line, even at 100 µg/mL, or cross-resistance with first line clinical trypanocides, such as diamidines and melaminophenyl arsenicals. Taken together, our study provides significant data in relation to the activity of chalcones and flavanones from P. salicifolium against both parasites in vitro. Further future research is suggested in order to investigate the mode of action of the extracted chalcones against the parasites.

16.
Biosaf Health ; 3(3): 148-155, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33458647

ABSTRACT

The novel coronavirus disease 2019 (COVID-19) is the third coronavirus outbreak in the last two decades. Emerging and re-emerging infections like COVID-19 pose serious challenges of the paucity of information and lack of specific cure or vaccines. This leaves utilisation of existing scientific data on related viral infections and repurposing relevant aetiologic and supportive therapies as the best control approach while novel strategies are developed and trialled. Many promising antiviral agents including lopinavir, ritonavir, remdesivir, umifenovir, darunavir, and oseltamivir have been repurposed and are currently trialled for the care for COVID-19 patients. Adjunct therapies for the management of symptoms and to provide support especially in severe and critically ill patients have also been identified. This review provides an appraisal of the current evidence for the rational use of frontline therapeutics in the management of COVID-19. It also includes updates regarding COVID-19 immunotherapy and vaccine development.

17.
J Cardiovasc Pharmacol Ther ; 26(2): 119-130, 2021 03.
Article in English | MEDLINE | ID: mdl-32812447

ABSTRACT

Revascularization surgeries such as coronary artery bypass grafting (CABG) are sometimes necessary to manage coronary heart disease (CHD). However, more than half of these surgeries fail within 10 years due to the development of intimal hyperplasia (IH) among others. The cytokine transforming growth factor-beta (TGFß) and its signaling components have been found to be upregulated in diseased or injured vessels, and to promote IH after grafting. Interventions that globally inhibit TGFß in CABG have yielded contrasting outcomes in in vitro and in vivo studies including clinical trials. With advances in molecular biology, it becomes clear that TGFß exhibits both protective and damaging roles, and only specific components such as some Smad-dependent TGFß signaling mediate vascular IH. The activin receptor-like kinase (ALK)-mediated Smad-dependent TGFß signaling pathways have been found to be activated in human vascular smooth muscle cells (VSMCs) following injury and in hyperplastic preimplantation vein grafts. It appears that focused targeting of TGFß pathway constitutes a promising therapeutic target to improve the outcome of CABG. This study dissects the role of TGFß pathway in CABG failure, with particular emphasis on the therapeutic potentials of specific targeting of Smad-dependent and ALK-mediated signaling.


Subject(s)
Activin Receptors, Type II/metabolism , Graft Occlusion, Vascular/physiopathology , Receptor, Transforming Growth Factor-beta Type I/metabolism , Transforming Growth Factor beta/metabolism , Coronary Artery Bypass , Coronary Disease/surgery , Humans , Hyperplasia/physiopathology , Myocytes, Smooth Muscle , Signal Transduction , Smad2 Protein
18.
Front Chem ; 8: 574103, 2020.
Article in English | MEDLINE | ID: mdl-33282826

ABSTRACT

Calliandra portoricensis is a medicinal plant growing freely in Nigeria. It is used traditionally to treat tuberculosis, as an anthelmintic and an abortifacient. Phytochemical fractionation and screening of its root extracts has yielded a novel (5-hydroxy-7-methoxy-4-oxo-1-chromanyl)-4-methoxy-p-benzoquinone (breverin)-substituted cassane diterpene, which was designated bokkosin. It was obtained from column chromatography of the ethyl acetate extract of the roots. The compound was characterized using IR, NMR (1D and 2D) and mass spectral data. Promising antiparasitic activity was observed against the kinetoplastid parasite Trypanosoma brucei brucei, as well as moderate activity against Trypanosoma congolense and Leishmania mexicana and low toxicity in mammalian cells, with the best in vitro EC50 values against T. b. brucei (0.69 µg/mL against a standard laboratory strain, and its multi-drug resistant clone (0.33 µg/mL). The effect on T. b. brucei in culture was rapid and dose-dependent, leading to apparently irreversible growth arrest and cell death after an exposure of just 2 h at 2 × or 4 × EC50. The identification of bokkosin constitutes the first isolation of this class of compound from any natural source and establishes the compound as a potential trypanocide that, considering its novelty, should now be tested for activity against other microorganisms as well.

19.
Pharm. pract. (Granada, Internet) ; 18(4): 0-0, oct.-dic. 2020. tab, graf
Article in English | IBECS | ID: ibc-202368

ABSTRACT

BACKGROUND: Occupational Violence is prevalent among healthcare workers, including pharmacists, and poses a big threat to their job satisfaction, safety, and social wellbeing. OBJECTIVE: This study seeks to assess the incidents and factors associated with occupational violence towards pharmacists in Nigeria. METHODS: A cross-sectional study was conducted among pharmacists practicing in Nigeria, using an online survey (Google FormTM). Occupational violence was assessed using a validated questionnaire. The survey was conducted and reported based on the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). Participants were recruited by sharing the survey link via social media platforms including WhatsApp, Facebook, LinkedIn, and Twitter. RESULTS: A total of 263 respondents returned the online questionnaire, with a completion rate of 99.2%. The prevalence of occupational violence was 92.7% (95% CI, 90 to 96). Violent events occurred among 48.7% of pharmacists with at least six years of experience, and 68.4% of hospital pharmacists. The commonly reported factors associated with the violence include long waiting times in the pharmacy (36.5%), refusal to fulfil aggressor's demands (22.1%), and counseling/poor communication (21.7%). Events related to verbal abuse were reported among 95% of the participants. The prevalence of violence was significantly higher among hospital pharmacists, compared with those practicing in administration/regulatory, and in community pharmacies (chi-square=10.213 (2); p = 0.006). Similarly, physical aggression was higher among hospital pharmacists (chi-square=10.646 (2), p = 0.005). CONCLUSIONS: The prevalence of occupational violence towards pharmacists practicing in Nigeria appeared to be high. Major factors associated with the violence were refusal to fulfil aggressors' demands and frustrations due to long waiting times at pharmacy. Recommended strategies to slowdown the incidences of violence were improved pharmacists' workforce, interprofessional harmony, and penalties against perpetrators


No disponible


Subject(s)
Humans , Male , Female , Adult , Workplace Violence/statistics & numerical data , Job Satisfaction , Pharmacists , Surveys and Questionnaires , Cross-Sectional Studies , Nigeria/epidemiology , Prevalence
20.
Pharm Pract (Granada) ; 18(4): 2080, 2020.
Article in English | MEDLINE | ID: mdl-33149792

ABSTRACT

BACKGROUND: Occupational Violence is prevalent among healthcare workers, including pharmacists, and poses a big threat to their job satisfaction, safety, and social wellbeing. OBJECTIVE: This study seeks to assess the incidents and factors associated with occupational violence towards pharmacists in Nigeria. METHODS: A cross-sectional study was conducted among pharmacists practicing in Nigeria, using an online survey (Google Form™). Occupational violence was assessed using a validated questionnaire. The survey was conducted and reported based on the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). Participants were recruited by sharing the survey link via social media platforms including WhatsApp, Facebook, LinkedIn, and Twitter. RESULTS: A total of 263 respondents returned the online questionnaire, with a completion rate of 99.2%. The prevalence of occupational violence was 92.7% (95% CI, 90 to 96). Violent events occurred among 48.7% of pharmacists with at least six years of experience, and 68.4% of hospital pharmacists. The commonly reported factors associated with the violence include long waiting times in the pharmacy (36.5%), refusal to fulfil aggressor's demands (22.1%), and counseling/poor communication (21.7%). Events related to verbal abuse were reported among 95% of the participants. The prevalence of violence was significantly higher among hospital pharmacists, compared with those practicing in administration/regulatory, and in community pharmacies (chi-square=10.213 (2); p=0.006). Similarly, physical aggression was higher among hospital pharmacists (chi-square=10.646 (2), p = 0.005). CONCLUSIONS: The prevalence of occupational violence towards pharmacists practicing in Nigeria appeared to be high. Major factors associated with the violence were refusal to fulfil aggressors' demands and frustrations due to long waiting times at pharmacy. Recommended strategies to slowdown the incidences of violence were improved pharmacists' workforce, interprofessional harmony, and penalties against perpetrators.

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