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1.
J Cancer Educ ; 32(4): 814-819, 2017 Dec.
Article in English | MEDLINE | ID: mdl-26932309

ABSTRACT

The majority of cancer patients receiving chemotherapy will consider taking complementary and alternative medicine (CAM) during their treatment. As biologically-active CAM may detrimentally interfere with chemotherapy treatment, cancer patients require evidence-based information on chemotherapy-CAM integration consequences. This study aimed to assess if the availability of a purpose-designed brochure within a cancer service aided doctors' discussions with their patients on CAM use and helped patients understand the effects of CAM during their chemotherapy treatment. Cancer care doctors consulting in an adult day unit completed a structured post-intervention feedback survey form (n = 17), and cancer patients receiving chemotherapy treatment were provided the brochure and completed the local health service consumer testing feedback form (n = 30). All cancer care doctors perceived a need for the brochure and recommended the brochure to their patients. All doctors thought the brochure made it easier for them to discuss CAM with their patients, and 59 % believed that it saved them time during patient consultations. Ninety percent of cancer patients reported the brochure had enough information to answer their CAM questions, and all patients thought the information was easy to read and understand. An evidence-based CAM-with-chemotherapy patient brochure was perceived to have enabled cancer care doctors to discuss CAM with their patients and to have answered patients' CAM questions.


Subject(s)
Complementary Therapies/adverse effects , Drug Therapy/methods , Pamphlets , Patient Education as Topic , Adult , Aged , Female , Humans , Male , Middle Aged , Surveys and Questionnaires
2.
Asia Pac J Clin Oncol ; 12(3): 265-74, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27044569

ABSTRACT

AIM: To determine which types of complementary and alternative medicine (CAM) are being used by cancer patients commencing curative-intent chemotherapy, whether the CAM taken has the potential to affect treatment efficacy, the reasons for patients' decisions to use CAM and whether these patients would like information on CAM safety with chemotherapy. METHODS: Seventy-five solid tumor malignancy patients receiving curative-intent treatment attending a cancer care day unit were interviewed about their CAM use on the day of receiving their first dose of chemotherapy. RESULTS: Sixty percent of study participants were using CAM at the start of chemotherapy treatment. Biologically active CAM assessed as having potential to interact with prescribed chemotherapy was ingested by 27% of patients, all of whom had routinely used CAM prior to cancer diagnosis. CAM was used by 51% of patients for supportive care reasons and by 28% of patients with the intention of treating their cancer. Patients' CAM decision-making was influenced by advice from family and friends, practitioners and casual acquaintances. Thirteen percent of patients were told by a CAM advice-giver not to have chemotherapy. The majority of patients (84%) would have liked to receive information on which CAM is safe to use with chemotherapy before treatment commenced. CONCLUSIONS: Patients being treated with curative intent, particularly those with a history of CAM use, may be taking biologically active CAM with potential to compromise their chemotherapy treatment. These patients want cancer-care health professionals to provide them evidence-based information on safe CAM use with chemotherapy and may be contending with alternative health advice to not have chemotherapy.


Subject(s)
Complementary Therapies , Neoplasms/therapy , Adult , Aged , Aged, 80 and over , Decision Making , Female , Humans , Male , Middle Aged , Motivation , Patient Education as Topic
4.
J Enzyme Inhib Med Chem ; 31(1): 63-6, 2016.
Article in English | MEDLINE | ID: mdl-25694064

ABSTRACT

In our continuing search for biologically active natural product(s) of plant origin, Buddleja saligna, a South African medicinal plant, was screened in line with its traditional use for antidiabetic (yeast alpha glucosidase inhibitory) and antiplasmodial (against a chloroquine sensitive strain of Plasmodium falciparum (NF54)) activities. The hexane fraction showed the most promising activity with regards to its antidiabetic (IC(50) = 260 ± 0.112 µg/ml) and antiplasmodial (IC(50) = 8.5 ± 1.6 µg/ml) activities. Using activity guided fractionation three known terpenoids (betulonic acid, betulone and spinasterol) were isolated from this species for the first time. The compounds displayed varying levels of biological activities (antidiabetic: 27.31 µg/ml ≥ IC(50) ≥ 5.6 µg/ml; antiplasmodial: 14 µg/ml ≥ IC(50) ≥ 2 µg/ml) with very minimal toxicity.


Subject(s)
Antimalarials/pharmacology , Buddleja/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Plant Leaves/chemistry , Plasmodium falciparum/drug effects , Terpenes/pharmacology , alpha-Glucosidases/metabolism , Antimalarials/chemistry , Antimalarials/isolation & purification , Dose-Response Relationship, Drug , Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/isolation & purification , Molecular Structure , Parasitic Sensitivity Tests , Structure-Activity Relationship , Terpenes/chemistry , Terpenes/isolation & purification , Yeasts/enzymology
5.
Bioorg Med Chem ; 23(15): 4163-4171, 2015 Aug 01.
Article in English | MEDLINE | ID: mdl-26174655

ABSTRACT

The synthesis and in vitro evaluation of novel triazole-linked chloroquinoline derivatives as potential antiplasmodial agents against Plasmodium falciparum is reported. The 15 synthesized target compounds were obtained by means of a copper(I)-mediated click reaction between a variety of 1,2- and 1,3-azidoamines and 7-chloro-N-(prop-2-yn-1-yl)quinolin-4-amine in moderate to good yields (53-85%). The compounds were screened for antiplasmodial activity against NF54 chloroquine-sensitive and Dd2 chloroquine-resistant strains, alongside chloroquine and artesunate as reference compounds. Six of the test compounds revealed a 3-5 fold increase in antiplasmodial activity against chloroquine-resistant strain Dd2 compared to chloroquine. Among the six compounds with good antiplasmodial activity, a reduced cross-resistance relative to artesunate (>3 fold in comparison to chloroquine) was observed, mainly in derivatives that incorporated chloroquine-resistance reversing pharmacophores. A general trend for reduced chloroquine cross-resistance was also detected among 12 out of the 15 compounds tested.


Subject(s)
Antimalarials/chemistry , Antimalarials/pharmacology , Chloroquine/chemistry , Plasmodium falciparum/drug effects , Triazoles/chemistry , Antimalarials/chemical synthesis , Artemisinins/pharmacology , Artesunate , Click Chemistry , Drug Evaluation, Preclinical/methods , Drug Resistance/drug effects , Molecular Structure
6.
Article in English | MEDLINE | ID: mdl-25802538

ABSTRACT

Biologically active CAM may detrimentally interfere with chemotherapy treatment, so cancer patients require targeted, evidence-based information on chemotherapy-CAM integration consequences. The object of this study was to investigate the potential for medical doctor recommendation and patient acceptance of a purpose-designed patient educational brochure on the safe use of CAM with chemotherapy. Cancer care doctors (n = 17) were provided a draft version of a patient educational brochure developed by the authors and completed a structured feedback form. Cancer patients receiving treatment (n = 12) were provided with the brochure and completed the local health service consumer testing feedback form. All 17 doctors perceived a need for the brochure and all would recommend the brochure to their patients. Approximately 59% of the doctors indicated they would recommend the brochure to all patients receiving chemotherapy and 41% preferred that only patients using CAM or who enquired about CAM be given the brochure. Cancer patients receiving chemotherapy reported that the brochure information answered their questions and was easy to understand. This evidence-based CAM-chemotherapy patient brochure may be a useful adjunct for use by cancer care health professionals to educate patients on the potential dangers of biologically active CAM use with chemotherapy and to provide patients with safe CAM alternatives.

7.
Antimicrob Agents Chemother ; 59(1): 38-45, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25313213

ABSTRACT

The relationships between antituberculosis drug exposure and treatment effects on humans receiving multidrug therapy are complex and nonlinear. In patients on treatment, an analysis of the rate of decline in the sputum bacillary burden reveals two slopes. The first is the α-slope, which is thought to reflect bactericidal effect, followed by a ß-slope, which is thought to reflect sterilizing activity. We sought to characterize the effects of standard first-line treatment on sterilizing activity. Fifty-four patients receiving combination therapy for pulmonary tuberculosis in a clinical trial had drug concentrations measured and Mycobacterium tuberculosis isolates available for MIC identification. Sputum sample cultures were performed at baseline and weekly for 8 weeks. A time-to-event model based on the days to positivity in the liquid cultures was used to estimate the ß-slope. The pharmacokinetic parameters of rifampin, isoniazid, ethambutol, and pyrazinamide were determined for each patient. Multivariate adaptive regression splines analyses, which simultaneously perform linear and nonlinear analyses, were used to identify the relationships between the predictors and the ß-slope. The potential predictors examined included HIV status, lung cavitation, 24-h area under the concentration-time curve (AUC), peak drug concentration (Cmax), AUC/MIC ratio, Cmax/MIC ratio, and the time that that concentration persisted above MIC. A rifampin Cmax of >8.2 mg/liter and a pyrazinamide AUC/MIC of >11.3 were key predictors of the ß-slope and interacted positively to increase the ß-slope. In patients with a rifampin AUC of <35.4 mg · h/liter, an increase in the pyrazinamide AUC/MIC and/or ethambutol Cmax/MIC increased the ß-slope, while increasing isoniazid Cmax decreased it, suggesting isoniazid antagonism. Antibiotic concentrations and MICs interact in a nonlinear fashion as the main drivers of a sterilizing effect. The results suggest that faster speeds of sterilizing effect might be achieved by omitting isoniazid and by increasing rifampin, pyrazinamide, and ethambutol exposures. However, isoniazid and ethambutol exposures may only be of importance when rifampin exposure is low. These findings need confirmation in larger studies. (This study has been registered at controlled-trials.com under registration no. ISRCTN80852505.).


Subject(s)
Antitubercular Agents/therapeutic use , Mycobacterium tuberculosis/drug effects , Sputum/microbiology , Tuberculosis/drug therapy , Adolescent , Adult , Area Under Curve , Disinfection , Drug Antagonism , Drug Synergism , Drug Therapy, Combination , Ethambutol/pharmacokinetics , Ethambutol/therapeutic use , Female , HIV Infections/complications , HIV Infections/virology , Humans , Isoniazid/pharmacokinetics , Isoniazid/therapeutic use , Male , Microbial Sensitivity Tests , Middle Aged , Mycobacterium tuberculosis/isolation & purification , Pyrazinamide/pharmacokinetics , Pyrazinamide/therapeutic use , Rifampin/pharmacokinetics , Rifampin/therapeutic use , Sterilization , Treatment Outcome , Young Adult
8.
Asia Pac J Clin Oncol ; 10(1): 1-10, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23910177

ABSTRACT

Complementary and alternative medicine (CAM) cover a broad and diverse group of treatments and products that do not tend to be widely used by conventional healthcare professions. CAM that is systemically absorbed is the most likely to interfere with concurrent chemotherapy and potentially cause harm to cancer patients. Patients receiving chemotherapy may be consuming CAM to treat cancer, to lessen chemotherapy side effects, for symptom management, or to treat conditions unrelated to their cancer. A small proportion of cancer patients decide to use CAM alone to treat cancer and delay conventional treatment. Cancer patients may be influenced in their CAM decision-making by others: practitioners, family, friends, spouse and even casual acquaintances met in waiting rooms and support groups. This influence may range from encouraging and supporting the patient's decision through to making the decisions for the patient. When tested in rigorous clinical trials, no CAM cancer treatments alone have shown benefit beyond placebo. With the exception of ginger to treat chemotherapy-induced nausea, there is no compelling evidence overriding risk to take complementary medicines for supportive care during chemotherapy treatment. There is, however, established evidence to use mind-body complementary therapies for supportive care during chemotherapy treatment.


Subject(s)
Complementary Therapies/psychology , Complementary Therapies/statistics & numerical data , Health Knowledge, Attitudes, Practice , Neoplasms/psychology , Neoplasms/therapy , Antineoplastic Agents/therapeutic use , Decision Making , Humans , Risk Factors
9.
Bioorg Med Chem Lett ; 24(2): 560-4, 2014 Jan 15.
Article in English | MEDLINE | ID: mdl-24373723

ABSTRACT

A series of compounds derived from the 2-amino-4-(2-pyridyl) thiazole scaffold was synthesized and tested for in vitro antimycobacterial activity against the Mycobacterium tuberculosis H37Rv strain, antiplasmodial activity against the chloroquine sensitive NF54 Plasmodium falciparum strain and cytotoxicity on a mammalian cell line. Optimal antimycobacterial activity was found with compounds with a 2-pyridyl ring at position 4 of the thiazole scaffold, a substituted phenyl ring at the 2-amino position, and an amide linker between the scaffold and the substituted phenyl. The antiplasmodial activity was best with compounds that had the phenyl ring substituted with hydrophobic electron withdrawing groups.


Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Antimalarials/chemical synthesis , Antimalarials/pharmacology , Thiazoles/chemical synthesis , Thiazoles/pharmacology , Animals , CHO Cells , Cricetinae , Cricetulus , Drug Evaluation, Preclinical/methods , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/physiology , Plasmodium falciparum/drug effects , Plasmodium falciparum/physiology
10.
Bioorg Med Chem Lett ; 23(1): 318-22, 2013 Jan 01.
Article in English | MEDLINE | ID: mdl-23195733

ABSTRACT

A variety of 5-, 6- and 8-(4-aminobutyloxy)quinolines as novel oxygen analogues of known 4- and 8-(4-aminobutylamino)quinoline antimalarial drugs was generated from hydroxyquinolines through a three-step approach with a rhodium-catalyzed hydroformylation as the key step. Antiplasmodial assays of these new quinolines revealed micromolar potency for all representatives against a chloroquine-sensitive strain of Plasmodium falciparum, and three compounds showed submicromolar activity against a chloroquine-resistant strain of P. falciparum with IC(50)-values ranging between 150 and 680 nM.


Subject(s)
Antimalarials/chemical synthesis , Chloroquine/analogs & derivatives , Animals , Antimalarials/chemistry , Antimalarials/toxicity , CHO Cells , Catalysis , Cell Survival/drug effects , Chloroquine/chemical synthesis , Chloroquine/toxicity , Cricetinae , Cricetulus , Drug Evaluation, Preclinical , Plasmodium falciparum/drug effects , Rhodium/chemistry
11.
Nat Prod Commun ; 7(10): 1263-6, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23156984

ABSTRACT

In our ongoing investigation of new compounds with activity against malaria parasites, we tested the in vitro antiplasmodial activity of fractions and purified compounds from Cassia fistula L., a plant traditionally used by native populations of Tanzania, Zimbabwe, Mozambique and Brazil to treat malaria or symptoms associated with this disease. Crude extracts from leaves, bark and fruits were tested for their antiplasmodial activity against the chloroquine-sensitive strain of Plasmodium falciparum (D10), where leaf extracts showed the highest activity. The chloroform extract of the leaves was further bioassay-guided fractionated using a combination of centrifugal partition chromatography and flash column chromatography. Three main antiplasmodial principles, phytol (1) (IC50 18.9 +/- 0.60 microM), lutein (2) (IC50 12.5 +/- 0.35 microM), and di-lineolylgalactopyranosyl-glycerol (DLGG) (IC50 5.8 +/- 0.27 microM) (3), were isolated and identified using spectroscopic methods. When the three active principles were tested for their cytotoxicity using a Chinese Hamster Ovarian (CHO) cell line, compound 3 showed very weak toxicity (IC50 75.9 +/- 0.28 microM), while the other two compounds were nontoxic, even at the highest concentration tested. The study provides evidence to support the use of Cassia fistula as an antimalarial remedy and describes the antiplasmodial constituents from the leaves.


Subject(s)
Antimalarials/isolation & purification , Antimalarials/pharmacology , Cassia/chemistry , Plasmodium falciparum/drug effects , Animals , CHO Cells , Cell Survival/drug effects , Chloroquine/pharmacology , Chromatography, High Pressure Liquid , Cricetinae , Cricetulus , Indicators and Reagents , Lutein/chemistry , Lutein/isolation & purification , Phytol/chemistry , Phytol/isolation & purification , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Leaves/chemistry , Solvents
12.
Planta Med ; 78(17): 1857-60, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23059633

ABSTRACT

Using activity-guided fractionation based on in vitro antibacterial assays, five biflavonoids, among them two new ones, were isolated from the aerial parts of Ormocarpum trichocarpum. The isolated compounds showed MIC values in the range of 4.0 to 136.7 µM against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Klebsiella pneumonia and IC50 values in the range of 4.30 to 94.32 µM against the chloroquine-sensitive D10 Plasmodium falciparum strain.


Subject(s)
Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Antimalarials/isolation & purification , Antimalarials/pharmacology , Biflavonoids/pharmacology , Fabaceae/chemistry , Anti-Bacterial Agents/chemistry , Antimalarials/chemistry , Bacillus subtilis/drug effects , Biflavonoids/chemistry , Biflavonoids/isolation & purification , Escherichia coli/drug effects , Inhibitory Concentration 50 , Klebsiella pneumoniae/drug effects , Microbial Sensitivity Tests , Molecular Structure , Plant Components, Aerial/chemistry , Plant Extracts/pharmacology , Plasmodium falciparum/drug effects , Staphylococcus aureus/drug effects
13.
Brain Res ; 1446: 1-11, 2012 Mar 29.
Article in English | MEDLINE | ID: mdl-22364637

ABSTRACT

Cellular stress or injury can result in mitochondrial dysfunction, which has been linked to many chronic neurological disorders including amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD). Stressed and dysfunctional mitochondria exhibit an increase in large conductance mitochondrial membrane currents and a decrease in bioenergetic efficiency. Inefficient energy production puts cells, and particularly neurons, at risk of death when energy demands exceed cellular energy production. Here we show that the candidate ALS drug dexpramipexole (DEX; KNS-760704; ((6R)-4,5,6,7-tetrahydro-N6-propyl-2,6-benzothiazole-diamine) and cyclosporine A (CSA) inhibited increases in ion conductance in whole rat brain-derived mitochondria induced by calcium or treatment with a proteasome inhibitor, although only CSA inhibited calcium-induced permeability transition in liver-derived mitochondria. In several cell lines, including cortical neurons in culture, DEX significantly decreased oxygen consumption while maintaining or increasing production of adenosine triphosphate (ATP). DEX also normalized the metabolic profile of injured cells and was protective against the cytotoxic effects of proteasome inhibition. These data indicate that DEX increases the efficiency of oxidative phosphorylation, possibly by inhibition of a CSA-sensitive mitochondrial conductance.


Subject(s)
Adrenergic beta-Antagonists/pharmacology , Energy Metabolism/drug effects , Membrane Potential, Mitochondrial/drug effects , Mitochondria/drug effects , Neurons/ultrastructure , Propranolol/pharmacology , Adenosine Triphosphate/metabolism , Analysis of Variance , Animals , Biophysical Phenomena/drug effects , Brain/cytology , Cell Survival/drug effects , Cells, Cultured , Cyclosporine/pharmacology , Dose-Response Relationship, Drug , Enzyme Inhibitors/pharmacology , Humans , Male , Mice , Mitochondrial Membranes/drug effects , Neuroblastoma/pathology , Neuroblastoma/ultrastructure , Oligopeptides/pharmacology , Oxygen Consumption/drug effects , Patch-Clamp Techniques , Rats , Rats, Sprague-Dawley
14.
J Ethnopharmacol ; 139(2): 471-7, 2012 Jan 31.
Article in English | MEDLINE | ID: mdl-22143154

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: The stem bark of Geissospermum vellosii has been traditionally used by the native population of northern South America to treat malaria. Indole alkaloids have been previously isolated from this plant, but the antiplasmodial constituents have not yet been described. As part of our ongoing investigations of new bioactive compounds with activity against malaria parasites, we tested the in vitro antiplasmodial activity of isolated fractions and purified alkaloids from Geissospermum vellosii. MATERIALS AND METHODS: Indole alkaloids were isolated and identified from a methanolic crude extract of Geissospermum vellosii bark using a combination of high performance counter current chromatography, mass spectrometry and nuclear magnetic resonance technologies. The methanolic extract, the crude alkaloid fractions and the purified compounds were tested for in vitro antiplasmodial activity against the chloroquine-sensitive strain of Plasmodium falciparum (D10). RESULTS: An indole alkaloid (4) along with four known indole alkaloids, geissolosimine (1), geissospermine (2), geissoschizoline (3), and vellosiminol (5) were isolated and structure elucidated. The antiplasmodial activity (IC(50)) of the methanolic crude extract was 2.22 µg/mL, while for the isolated compounds it ranged from 0.96 µM to 13.96 µM except for (5) which showed a low activity (157 µM). Geissolosimine (1) showed the highest antiplasmodial activity (0.96 µM). CONCLUSIONS: This study provides evidence to support the use of Geissospermum vellosii as an antimalarial agent, as used by the native populations. Geissolosimine (1) is a lead molecular structure for possible antimalarial drug development.


Subject(s)
Antimalarials/pharmacology , Apocynaceae , Indole Alkaloids/pharmacology , Plasmodium falciparum/drug effects , Animals , Antimalarials/chemistry , Antimalarials/isolation & purification , Antimalarials/toxicity , Apocynaceae/chemistry , CHO Cells , Cell Survival/drug effects , Chromatography, High Pressure Liquid , Cricetinae , Cricetulus , Dose-Response Relationship, Drug , Indole Alkaloids/chemistry , Indole Alkaloids/isolation & purification , Indole Alkaloids/toxicity , Inhibitory Concentration 50 , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Structure , Parasitic Sensitivity Tests , Plant Bark , Plants, Medicinal
15.
Malar J ; 10: 295, 2011 Oct 11.
Article in English | MEDLINE | ID: mdl-21985233

ABSTRACT

BACKGROUND: Anti-malarial drug resistance threatens to undermine efforts to eliminate this deadly disease. The resulting omnipresent requirement for drugs with novel modes of action prompted a national consortium initiative to discover new anti-plasmodial agents from South African medicinal plants. One of the plants selected for investigation was Dicoma anomala subsp. gerrardii, based on its ethnomedicinal profile. METHODS: Standard phytochemical analysis techniques, including solvent-solvent extraction, thin-layer- and column chromatography, were used to isolate the main active constituent of Dicoma anomala subsp. gerrardii. The crystallized pure compound was identified using nuclear magnetic resonance spectroscopy, mass spectrometry and X-ray crystallography. The compound was tested in vitro on Plasmodium falciparum cultures using the parasite lactate dehydrogenase (pLDH) assay and was found to have anti-malarial activity. To determine the functional groups responsible for the activity, a small collection of synthetic analogues was generated - the aim being to vary features proposed as likely to be related to the anti-malarial activity and to quantify the effect of the modifications in vitro using the pLDH assay. The effects of the pure compound on the P. falciparum transcriptome were subsequently investigated by treating ring-stage parasites (alongside untreated controls), followed by oligonucleotide microarray- and data analysis. RESULTS: The main active constituent was identified as dehydrobrachylaenolide, a eudesmanolide-type sesquiterpene lactone. The compound demonstrated an in vitro IC50 of 1.865 µM against a chloroquine-sensitive strain (D10) of P. falciparum. Synthetic analogues of the compound confirmed an absolute requirement that the α-methylene lactone be present in the eudesmanolide before significant anti-malarial activity was observed. This feature is absent in the artemisinins and suggests a different mode of action. Microarray data analysis identified 572 unique genes that were differentially expressed as a result of the treatment and gene ontology analysis identified various biological processes and molecular functions that were significantly affected. Comparison of the dehydrobrachylaenolide treatment transcriptional dataset with a published artesunate (also a sesquiterpene lactone) dataset revealed little overlap. These results strengthen the notion that the isolated compound and the artemisinins have differentiated modes of action. CONCLUSIONS: The novel mode of action of dehydrobrachylaenolide, detected during these studies, will play an ongoing role in advancing anti-plasmodial drug discovery efforts.


Subject(s)
Antimalarials/pharmacology , Asteraceae/chemistry , Plant Extracts/pharmacology , Plasmodium falciparum/drug effects , Sesquiterpenes/pharmacology , Structure-Activity Relationship , Antimalarials/chemistry , Antimalarials/isolation & purification , Antimalarials/metabolism , Asteraceae/genetics , Asteraceae/metabolism , Chemical Fractionation , Chromatography , Crystallography, X-Ray , Gene Expression Profiling , Gene Expression Regulation/drug effects , Humans , Magnetic Resonance Spectroscopy , Mass Spectrometry , Microarray Analysis , Plant Extracts/isolation & purification , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , Sesquiterpenes/metabolism , South Africa
16.
J Chromatogr B Analyt Technol Biomed Life Sci ; 879(21): 1886-92, 2011 Jul 01.
Article in English | MEDLINE | ID: mdl-21641879

ABSTRACT

The development of new antiplasmodial drugs is of primary importance due to the growing problem of multi-drug resistance of malaria parasites. Spilanthes acmella, a plant traditionally used for the treatment of toothache, was targeted as a lead for its potential antiplasmodial activity. A systematic approach for investigating a suitable centrifugal partition chromatography (CPC) solvent system for N-alkylamides separation was reported. The partition behavior of three N-alkylamides has been studied using several biphasic solvent mixtures in search of an adequate CPC solvent system for this class of compounds. Major N-alkylamides in S. acmella were isolated from a methanolic crude extract of flowers by CPC with the solvent system heptanes-ethyl acetate-methanol-water (3:2:3:2, v/v/v/v). Four N-alkylamides were purified and the structures were illustrated by electrospray ionization-ion trap-time of flight-mass spectrometry (ESI-IT-TOF-MS), ¹H nuclear magnetic resonance (¹H NMR) and ¹³C nuclear magnetic resonance (¹³C NMR). The CPC fractions, which contained natural mixtures of phytochemicals, demonstrated significantly higher antiplasmodial activity compared to corresponding purified N-alkylamides, thus suggesting that interactions between these N-alkylamides may potentiate antiplasmodial bioactivity.


Subject(s)
Amides/isolation & purification , Antimalarials/isolation & purification , Asteraceae/chemistry , Chromatography, Liquid/methods , Flowers/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Amides/chemistry , Amides/pharmacology , Animals , Antimalarials/chemistry , Antimalarials/pharmacology , CHO Cells , Cell Survival/drug effects , Centrifugation , Cricetinae , Cricetulus , Nuclear Magnetic Resonance, Biomolecular , Plasmodium falciparum/drug effects , Reproducibility of Results
17.
J Med Chem ; 54(10): 3637-49, 2011 May 26.
Article in English | MEDLINE | ID: mdl-21500839

ABSTRACT

Analogues of the previously reported antimalarial hybrid compounds 8b and 12 were proposed with the aim of identifying compounds with improved solubility and retained antimalarial potency. In silico characterization predicted improved solubilities of the analogues, particularly at low pH; they retained acceptable predicted permeability properties but were predicted to be susceptible to hepatic metabolism. These analogues were synthesized and found to exhibit notable in vitro antimalarial activity. Compounds 25 and 27 were the most active of the analogues. In vitro metabolism studies indicated susceptibility of the analogues to hepatic metabolism. There was also evidence of primary glucuronidation for analogues 24-27. Presumed cis-trans isomerism of 12, 22, and 23 under in vitro metabolism assay conditions was also observed, with differences in the nature and rates of metabolism observed between isomers. Biochemical studies strongly suggested that inhibition of hemozoin formation is the primary mechanism of action of these analogues.


Subject(s)
Antiparasitic Agents/chemical synthesis , Chalcone/chemistry , Chemistry, Pharmaceutical/methods , Quinolines/chemistry , Animals , Antimalarials/pharmacology , Antiparasitic Agents/pharmacology , Caco-2 Cells , Computational Biology/methods , Drug Design , Drug Evaluation, Preclinical/methods , Humans , Hydrogen-Ion Concentration , Inhibitory Concentration 50 , Liver/metabolism , Permeability
18.
J Ethnopharmacol ; 133(1): 26-30, 2011 Jan 07.
Article in English | MEDLINE | ID: mdl-20826204

ABSTRACT

AIM OF THE STUDY: The objective of this study was to isolate and characterize the active constituents of the traditionally used antimalarial plant Liriodendron tulipifera by antiplasmodial-assay guided fractionation. MATERIALS AND METHODS: Bark and leaves were extracted with solvents of increasing polarity. Fractions were generated using flash chromatography, counter current chromatography and preparative HPLC and subjected to in vitro antiplasmodial and cytotoxicity assays. Active fractions were subjected to further fractionation until pure compounds were isolated, for which the IC(50) values were calculated. RESULTS AND DISCUSSION: Six known aporphine alkaloids, asimilobine (1), norushinsunine (2), norglaucine (3), liriodenine (4), anonaine (5) and oxoglaucine (6) were found to be responsible for the antiplasmodial activity of the bark. Leaves yielded two known sesquiterpene lactones, peroxyferolide (7) and lipiferolide (8) with antiplasmodial activity. The antiplasmodial activity of (2) (IC(50)=29.6 µg/mL), (3) (IC(50)=22.0 µg/mL), (6) (IC(50)=9.1 µg/mL), (7) (IC(50)=6.2 µg/mL) and (8) (IC(50)=1.8 µg/mL) are reported for the first time. CONCLUSION: This work supports the historical use of Liriodendron tulipifera as an antimalarial remedy of the United States and characterizes its antiplasmodial constituents.


Subject(s)
Alkaloids/pharmacology , Antimalarials/pharmacology , Lactones/pharmacology , Liriodendron/chemistry , Malaria/drug therapy , Phytotherapy , Plant Extracts/pharmacology , Sesquiterpenes/pharmacology , Alkaloids/chemistry , Alkaloids/isolation & purification , Antimalarials/chemistry , Antimalarials/isolation & purification , Aporphines/chemistry , Aporphines/isolation & purification , Aporphines/pharmacology , Lactones/chemistry , Lactones/isolation & purification , Plant Bark , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Leaves , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , United States
20.
Nat Prod Commun ; 5(12): 1869-72, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21299109

ABSTRACT

The hexane extract from the leaves of Canella winterana exhibited strong activity against the chloroquine sensitive (CQS) strain of Plasmodium falciparum (D10) in vitro (IC50 2.53 microg/mL). Bioassay guided fractionation of this extract has led to the isolation of 5 drimane-type sesquiterpenoids: 9-epideoxymuzigadial, 9-deoxymuzigadial, muzigadial, 3-beta-acetoxypolygodial and the newly isolated hemiacetal, named muzigodiol, with IC50-values of 1.01, 2.19, 0.31, 2.77 and 7.43 microg/mL, respectively. The first four compounds were tested for their cytotoxicity using Chinese Hamster Ovarian (CHO) cells, where they showed IC50-values of 1.82, 33.69, 1.18, and 58.31 microg/mL, respectively. A structure-activity relationship is discussed.


Subject(s)
Antimalarials/pharmacology , Magnoliopsida/chemistry , Sesquiterpenes/pharmacology , Animals , CHO Cells , Cell Survival/drug effects , Cricetinae , Cricetulus , Plasmodium falciparum/drug effects , Polycyclic Sesquiterpenes , Sesquiterpenes/chemistry , Sesquiterpenes/isolation & purification , Structure-Activity Relationship
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