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1.
Planta Med ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39029914

RESUMO

There is considerable interest in the utilization of plants against inflammation. Over 50 species of the plant family Amaryllidaceae are known for such usage in traditional medicine. This review was undertaken to identify the chemical principles responsible for these anti-inflammatory effects. It describes the findings from in vitro, in vivo and in silico studies as well as the probes made on the mechanisms of action. The literature search returned over 600 hits, of which around 130 were chosen for their relevance to the text. Over 140 compounds have thus far been screened for anti-inflammatory effects. These were mostly isoquinoline alkaloids, but also included other classes of secondary metabolites such as chromones, flavonoids and triterpenoids. In vitro studies were carried out in mononuclear cells such as lymphocytes, monocytes, neutrophils and macrophages, against which no serious side effects were observed. The constituents were also effective against inflammation induced by physical and chemical stimuli in a variety of murine test subjects. Chief among the compounds were the isoquinoline alkaloids lycorine and narciclasine, which displayed potent effects against pain, swelling, asthma and arthritis amongst others. From a mechanistic perspective several of the compounds were shown to mediate in inflammatory pathways, notably via the modulation of both pro-inflammatory (such as NF-κB, TNF-α and IL-1) and anti-inflammatory (such as IL-10 and TGF-ß) factors. Useful insights also emerged from active-site docking studies of some of the compounds. The Amaryllidaceae affords a rich and diverse platform for the discovery of potential anti-inflammatory drugs.

2.
Planta Med ; 89(1): 99-115, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34921374

RESUMO

The Amaryllidaceae features prominently amongst bulbous flowering plant families. Accommodating about a third of its species, South Africa affords a sound basis for Amaryllidaceae plant research. Boophone, Nerine, Crossyne, Clivia, Cryptostephanus, Haemanthus and Scadoxus have been well-represented in such endeavors. The account herein summarizes the studies undertaken between 2013 - 2020 on these genera in regards to their chemical and biological characteristics. A total of 136 compounds comprising 63 alkaloids and 73 non-alkaloid entities were described during this period from eighteen members of the title genera. The alkaloids were reflective of the structural diversity found in eight isoquinoline alkaloid groups of the Amaryllidaceae. Of these, the crinane (29 compounds), lycorane and homolycorine (11 compounds each) groups were the most-represented. The non-alkaloid substances were embracive of the same number of unrelated groups including, acids, phenolics, flavonoids and triterpenoids. A wide variety of assays were engaged to ascertain the biological activities of the isolated compounds, notably in regards to cancer and motorneuron-related diseases. There were also attempts made to determine the antimicrobial, anti-inflammatory and antioxidant effects of some of the substances. New information has also emerged on the herbicidal, insecticidal and plant growth regulatory effects of selected alkaloid principles. Coupled to the biological screening measures were in instances probes made to establish the molecular basis to some of the activities, particularly in relation to cancer and Parkinson's disease.


Assuntos
Alcaloides , Alcaloides de Amaryllidaceae , Amaryllidaceae , África do Sul , Amaryllidaceae/química , Alcaloides de Amaryllidaceae/química , Alcaloides/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química
3.
Planta Med ; 87(12-13): 916-936, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33706400

RESUMO

Over 600 alkaloids have to date been identified in the plant family Amaryllidaceae. These have been arranged into as many as 15 different groups based on their characteristic structural features. The vast majority of studies on the biological properties of Amaryllidaceae alkaloids have probed their anticancer potential. While most efforts have focused on the major alkaloid groups, the volume and diversity afforded by the minor alkaloid groups have promoted their usefulness as targets for cancer cell line screening purposes. This survey is an in-depth review of such activities described for around 90 representatives from 10 minor alkaloid groups of the Amaryllidaceae. These have been evaluated against over 60 cell lines categorized into 18 different types of cancer. The montanine and cripowellin groups were identified as the most potent, with some in the latter demonstrating low nanomolar level antiproliferative activities. Despite their challenging molecular architectures, the minor alkaloid groups have allowed for facile adjustments to be made to their structures, thereby altering the size, geometry, and electronics of the targets available for structure-activity relationship studies. Nevertheless, it was seen with a regular frequency that the parent alkaloids were better cytotoxic agents than the corresponding semisynthetic derivatives. There has also been significant interest in how the minor alkaloid groups manifest their effects in cancer cells. Among the various targets and pathways in which they were seen to mediate, their ability to induce apoptosis in cancer cells is most appealing.


Assuntos
Alcaloides , Alcaloides de Amaryllidaceae , Amaryllidaceae , Alcaloides/farmacologia , Alcaloides de Amaryllidaceae/farmacologia , Apoptose , Citotoxinas
4.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361724

RESUMO

Orchids are rich treasure troves of various important phytomolecules. Among the various medicinal orchids, Ansellia africana stands out prominently in the preparing of various herbal medicines due to its high therapeutic importance. The nodal explants of A. africana were sampled from asymbiotically germinated seedlings on basal Murashige and Skoog (MS) medium and were micropropagated in MS medium supplemented with 3% sucrose and 10 µM meta topolin (mT) + 5 µM naphthalene acetic acid (NAA) +15 µM indole butyric acid (IBA) + 30 µM phloroglucinol (PG). In the present study, the essential oil was extracted by hydrodistillation and the oleoresins by the solvent extraction method from the micropropagated A. africana. The essential oil and the oleoresins were analysed by Gas Chromatography (GC) and GC/MS (Mass spectrometry). A total of 84 compounds were identified. The most predominant components among them were linoleic acid (18.42%), l-ascorbyl 2,6-dipalmitate (11.50%), linolenic acid (10.98%) and p-cresol (9.99%) in the essential oil; and eicosane (26.34%), n-butyl acetate (21.13%), heptadecane (16.48%) and 2-pentanone, 4-hydroxy-4-methyl (11.13%) were detected in the acetone extract; heptadecane (9.40%), heneicosane (9.45%), eicosane (6.40%), n-butyl acetate (14.34%) and styrene (22.20%) were identified and quantified in the ethyl acetate extract. The cytotoxic activity of essential oil and oleoresins of micropropagated A. africana was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide) assay on Vero cells compared to the standard drug doxorubicin chloride. The present research contains primary information about the therapeutic utility of the essential oil and oleoresins of A. africana with a promising future research potential of qualitative and quantitative improvement through synchronised use of biotechnological techniques.


Assuntos
Citotoxinas/isolamento & purificação , Óleos Voláteis/isolamento & purificação , Orchidaceae/química , Extratos Vegetais/isolamento & purificação , Plântula/química , Acrilatos/isolamento & purificação , Alcanos/isolamento & purificação , Animais , Ácido Ascórbico/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cresóis/isolamento & purificação , Meios de Cultura/química , Meios de Cultura/farmacologia , Citotoxinas/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Hidroponia/métodos , Ácido Linoleico/isolamento & purificação , Extração Líquido-Líquido/métodos , Óleos Voláteis/farmacologia , Orchidaceae/metabolismo , Palmitatos/isolamento & purificação , Pentanóis/isolamento & purificação , Pentanonas/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais , Plântula/metabolismo , África do Sul , Estireno/isolamento & purificação , Células Vero , Ácido alfa-Linolênico/isolamento & purificação
5.
S Afr J Bot ; 139: 386-398, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33753960

RESUMO

Infection by the novel coronavirus SARS-CoV-2 causing the coronavirus disease (COVID-19), is currently a global pandemic with more than two million deaths to date. Though a number of vaccines have recently been approved against the virus, availability remains a big challenge, and also acceptance by most people has become a big debate. This review discusses possible/proposed natural product remedies and some major conventional treatment options used to manage the infection and, safety concerns on the use of unproven or unapproved health products against COVID-19. An extensive literature review indicated that the influx of unproven and unapproved health products in the global market are on the rise, leading to various forms of self- medication. To this effect, there have been warnings by the United States Food and Drug Administration and the World Health Organisation against the use of such products. Conventional drugs such as remdesivir, chloroquine/hydroxychloroquine and dexamethasone are the major proposed drugs that are currently undergoing clinical trials for the management of this disease. Efforts are being made globally in the search for possible therapeutics which may be the best way to eradicating this disease. Some countries have approved the use of natural products in the management of COVID-19, despite little or no clinical evidence on their efficacy and safety. Natural products may hold a great potential in the fight against COVID-19 but without detailed clinical trials, their potency against the virus and their safe use cannot be established. To attain this goal, extensive research followed by clinical studies are needed. Collaborative efforts between researchers, clinicians, governments and traditional medicinal practitioners in the search and development of safe and effective therapeutics from natural products for the treatment of COVID-19 could be a potential option.

6.
Plant Physiol ; 181(2): 458-470, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31413205

RESUMO

The biologically active molecules karrikinolide (KAR1) and trimethylbutenolide (TMB) present in wildfire smoke play a key role in regulating seed germination of many plant species. To elucidate the physiological mechanism by which smoke-water (SW), KAR1, and TMB regulate seed germination in photosensitive 'Grand Rapids' lettuce (Lactuca sativa), we investigated levels of the dormancy-inducing hormone abscisic acid (ABA), three auxin catabolites, and cytokinins (26 isoprenoid and four aromatic) in response to these compounds. Activity of the hydrolytic enzymes α-amylase and lipase along with stored food reserves (lipids, carbohydrate, starch, and protein) were also assessed. The smoke compounds precisely regulated ABA and hydrolytic enzymes under all light conditions. ABA levels under red (R) light were not significantly different in seeds treated with TMB or water. However, TMB-treated seeds showed significantly inhibited germination (33%) compared with water controls (100%). KAR1 significantly enhanced total isoprenoid cytokinins under dark conditions in comparison with other treatments; however, there was no significant effect under R light. Enhanced levels of indole-3-aspartic acid (an indicator of high indole-3-acetic acid accumulation, which inhibits lettuce seed germination) and absence of trans-zeatin and trans-zeatin riboside (the most active cytokinins) in TMB-treated seeds might be responsible for reduced germination under R light. Our results demonstrate that SW and KAR1 significantly promote lettuce seed germination by reducing levels of ABA and enhancing the activity of hydrolytic enzymes, which aids in mobilizing stored reserves. However, TMB inhibits germination by enhancing ABA levels and reducing the activity of hydrolytic enzymes.


Assuntos
4-Butirolactona/análogos & derivados , 4-Butirolactona/farmacologia , Furanos/farmacologia , Germinação/efeitos dos fármacos , Lactuca/efeitos dos fármacos , Piranos/farmacologia , Fumaça , Interações Medicamentosas , Lactuca/metabolismo , Fitocromo/metabolismo , Reguladores de Crescimento de Plantas/metabolismo
7.
J Cell Biochem ; 120(12): 19555-19566, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31264273

RESUMO

The fungal genus Puccinia, comprising of several menacing pathogens, has been a persistent peril to global agriculture. Genome sequencing of various members of Puccinia offers a scope to excavate their genomic riddles. The present study has been addressed at exploring the complex niceties of codon and amino acid usage patterns and subsequent elucidation of the determinants that drive such behavior. Multivariate statistical analysis revealed a complex interplay of natural selection for translation and compositional bias to be operational on the codon usage patterns. Gene expression level was observed to be the most competent factor governing codon usage behavior of the genus. In spite of subtle AT richness of the genus, potential highly expressed gene sets were found to preferentially employ GC rich optimal codons. Estimation of relative dinucleotide abundance revealed preference toward the employment of GpA, CpA, TpC, and TpG dinucleotides and restraint from using TpA dinucleotide among the members of the genus. Extensive codon context analysis revealed that codon pairs with GpA, CpA, TpC, and TpG dinucleotides were over-represented and codon pairs with TpA dinucleotide were extensively avoided at the codon-codon (cP3-cA1) junctions. Amino acid usage signatures of the genus were found to be influenced considerably by several imperative factors like aromatic and hydrophobic character of the encoded gene products, genomic compositional constraint, and gene expressivity. Detailed know-how of the potential highly expressed gene sets and associated optimal codons in the genus promise to be informative for the scientific community engaged in combating Puccinia pathogenesis.


Assuntos
Aminoácidos/genética , Basidiomycota/genética , Uso do Códon , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Mutação , Seleção Genética , Agricultura , Genoma Fúngico , Interações Hidrofóbicas e Hidrofílicas
8.
Bioorg Med Chem Lett ; 29(20): 126642, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31515186

RESUMO

Protozoan-borne diseases are prominent amongst diseases caused by parasites. Given their alarming morbidity and mortality statistics, there is ever growing interest in new therapies against these diseases. Whilst synthetic drugs such as benznidazole and melarsoprol have had a profound influence on the clinical setup, there has been significant interest in the phytochemical platform to also deliver such drug candidates. The plant family Amaryllidaceae is recognizable for its isoquinoline alkaloids, which exhibit attractive molecular architectures and interesting biological properties. This survey focuses on the antiprotozoal activities of 73 of such substances described in 18 different species of the Amaryllidaceae. Of these, 2-O-acetyllycorine was identified as the most potent (IC50 0.15 µg/mL against Trypansoma brucei brucei). Also considered are structure-activity relationships which have served to modulate activities, as well as the plausible mechanisms that underpin these effects and afford insight to the Amaryllidaceae alkaloid antiprotozoal pharmacophore.


Assuntos
Alcaloides de Amaryllidaceae/química , Amaryllidaceae/química , Antiprotozoários/química , Isoquinolinas/química , Extratos Vegetais/química , Alcaloides de Amaryllidaceae/farmacologia , Antiprotozoários/farmacologia , Diterpenos/química , Avaliação Pré-Clínica de Medicamentos , Humanos , Isoquinolinas/farmacologia , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Relação Estrutura-Atividade , Trypanosoma brucei brucei/efeitos dos fármacos
9.
J Nat Prod ; 82(5): 1372-1376, 2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-30933514

RESUMO

In this study, an extract from the bulbs of Cyrtanthus contractus showed strong anti-inflammatory activity in vitro. The extract was partially separated into 14 fractions and analyzed by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry metabolomics, and the correlation coefficients were calculated between biological activities and metabolite levels. As a result, the top-scoring metabolite narciclasine (1) is proposed as the active principle of C. contractus. This was confirmed by comparing the biological effect of crude extract with that of an authentic standard.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Amaryllidaceae/química , Anti-Inflamatórios não Esteroides/farmacologia , Metabolômica , Fenantridinas/farmacologia , Alcaloides de Amaryllidaceae/química , Anti-Inflamatórios não Esteroides/química , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Molécula 1 de Adesão Intercelular/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/metabolismo , Espectrometria de Massas , Fenantridinas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química
10.
Planta Med ; 85(8): 637-647, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30909312

RESUMO

The spread of malaria is thought to have followed human expansion out of Africa some 60 - 80 thousand years ago. With its prevalence in pantropical countries of the world and epicenter localized in Africa, malaria is now considered an unnecessary burden to overworked and under-resourced healthcare structures. Plants have long afforded a fertile hunting ground for the search and identification of structurally diverse antimalarial agents, such as quinine and artemisinin. This survey examines the antiparasitic properties of the family Amaryllidaceae via the antiplasmodial activities demonstrated for its lycorane alkaloid principles. Of these, 24 were natural compounds identified in 20 species from 11 genera of the Amaryllidaceae family, whilst the remaining 28 were synthetically derived entities based on the lycorane skeleton. These were screened against ten different strains of the malarial parasite Plasmodium falciparum, wherein the parent compound lycorine was shown to be the most potent with an IC50 of 0.029 µg/mL in the FCR-3 strain seen to be the best. Structure-activity relationship studies revealed that good activities were detectable across both the natural compounds as well as the synthetically accessed derivatives. Such studies also highlighted that there are several inherent structural features that define the lycorane alkaloid antiplasmodial pharmacophore, such as the nature of its ring systems and properties of its substituents. Mechanistically, a limited number of studies confirmed that lycorane alkaloids manifest their action by targeting enzymes associated with the plasmodial FAS-II biosynthetic pathways. Overall, these alkaloids have provided useful, convenient, and accessible scaffolds for antimalarial-based drug discovery.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Amaryllidaceae/química , Antimaláricos/farmacologia , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/isolamento & purificação , Animais , Antimaláricos/química , Antimaláricos/isolamento & purificação , Humanos , Plasmodium falciparum/efeitos dos fármacos , Relação Estrutura-Atividade
11.
World J Microbiol Biotechnol ; 35(8): 118, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332540

RESUMO

The fungal genus Ustilago consists of intimidating pathogens associated with disease manifestations in plants of agricultural importance and gravity. Rapid progress of genome sequencing has opened the floodgates for biological research. Availability of Ustilago genomes provides a scope to explore complex codon and amino acid usage patterns in the genus. An extensive scrutiny of the factors underlying the complex modalities of codon and amino acid usage in Ustilago has been executed in the present analysis. Multivariate statistical analysis revealed a dominant effect of natural selection pressure, aimed at translational accuracy, to be operative on the codon usage behavior. Subtle impact of GC compositional constraint was also evident on the codon usage patterns. Gene expressivity was inferred to be the most crucial determinant governing observed codon usage variations. Amino acid usage patterns were found to be significantly governed by aromatic and hydrophobic characters of the encoded proteins. GC content and length of protein coding sequences also had considerable influence on the amino acid usage signatures. Extensive analysis of codon context variations revealed that UpA dinucleotides were strictly avoided at the codon-codon junctions (cP3-cA1) which might be attributed to reduce the risk of nonsense mutations and subsequently, improve translational finesse. Identification of the optimal codons, employed preferentially among the genes with high expressivity, and estimation of preferred and avoided codon pairs in Ustilago promises to be useful pertaining to mutational experiments at the codonic level, targeted to thwart the growth of Ustilago and combat associated pathogenesis.


Assuntos
Perfilação da Expressão Gênica , Ustilago/genética , Aminoácidos/metabolismo , Composição de Bases/genética , Códon , Seleção Genética/genética , Ustilago/metabolismo , Sequenciamento Completo do Genoma
12.
Ecotoxicol Environ Saf ; 147: 43-48, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28826029

RESUMO

Extreme temperatures, drought and salinity stress adversely affect seed germination and seedling growth in crop species. Seed priming has been recognized as an indispensable technique in the production of stress-tolerant plants. Seed priming increases seed water content, improves protein synthesis using mRNA and DNA and repair mitochondria in seeds prior to germination. The current study aimed to determine the role of biostimulants-seed-priming during germination and seedling growth of Ceratotheca triloba (Bernh.) Hook.f. (an indigenous African leafy vegetable) under low temperature, low osmotic potential and salinity stress conditions. Ceratotheca triloba seeds were primed with biostimulants [smoke-water (SW), synthesized smoke-compound karrikinolide (KAR1), Kelpak® (commercial seaweed extract), phloroglucinol (PG) and distilled water (control)] for 48h at 25°C. Thereafter, primed seeds were germinated at low temperatures, low osmotic potential and high NaCl concentrations. Low temperature (10°C) completely inhibited seed germination. However, temperature shift to 15°C improved germination. Smoke-water and KAR1 enhanced seed germination with SW improving seedling growth under different stress conditions. Furthermore, priming seeds with Kelpak® stimulated percentage germination, while PG and the control treatment improved seedling growth at different PEG and NaCl concentrations. Generally, high concentrations of PEG and NaCl brought about detrimental effects on seed germination and seedling growth. Findings from this study show the potential role of seed priming with biostimulants in the alleviation of abiotic stress conditions during seed germination and seedling growth in C. triloba plants.


Assuntos
Furanos/farmacologia , Germinação/efeitos dos fármacos , Pedaliaceae/efeitos dos fármacos , Piranos/farmacologia , Plântula/efeitos dos fármacos , Sementes/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Temperatura Baixa , Secas , Osmose , Pedaliaceae/crescimento & desenvolvimento , Salinidade , Plântula/crescimento & desenvolvimento , África do Sul
13.
BMC Complement Altern Med ; 18(1): 272, 2018 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-30285713

RESUMO

BACKGROUND: Tithonia diversifolia and T. rotundifolia belong to the Asteraceae family and are native to Mexico and Central America. These plants have become invasive in parts of tropical Africa and Asia where they have become an ecological, agricultural and economic burden. Tithonia diversifolia is exploited by locals in its native and most parts of its invasive range as a source of medicines; however, T. rotundifolia is only used for medicinal purposes in one country in the native range (Venezuela) and none in the invasive range. Although T. diversifolia has been studied for different biological activities, little or no attention has been given to T. rotundifolia. This study compared the antimicrobial activity, phytochemistry, identification of bioactive compound(s) and toxicity levels of different leaf extracts and fractions of T. diversifolia and T. rotundifolia. METHODS: Antimicrobial activity was evaluated against seven pathogenic bacteria, four non-pathogenic Mycobacterium species and three fungal species using serial microdilution assays. Phytochemical contents were determined through standard methods of analysis. UPLC/MS was used to analyse the fractions to identify possible bioactive compounds that may be responsible for bioactivity, while toxicity tests were carried out using the colorimetric MTT assay and the Ames test. RESULTS: Both species had a range of antimicrobial activity against bacterial, mycobacterial and fungal species. However, T. rotundifolia displayed better activity against most of the strains tested with minimum inhibitory concentration values ranging between 0.01 and 0.07 mg/ml. Both species were rich in phenolics, flavonoids and tannins. Tagitinin A was identified as the main compound present in both species, and this compound may be responsible for the antimicrobial activity displayed. Toxicity tests showed that T. diversifolia was cytotoxic at concentrations used in this study, while T. rotundifolia was not. Both species did not show any mutagenic/genotoxic effects. CONCLUSION: The above results suggest that both species may be further developed as a source of antimicrobials for the treatment of infections caused by opportunistic pathogens. They may also serve as alternatives to highly exploited plant species with the same medicinal properties. However, T. diversifolia should be used with caution as it may be toxic.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Asteraceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Animais , Anti-Infecciosos/toxicidade , Bactérias/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cromatografia Líquida de Alta Pressão , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Espécies Introduzidas , Espectrometria de Massas , Estrutura Molecular , Extratos Vegetais/toxicidade , África do Sul , Células Vero
14.
Phytother Res ; 32(6): 976-984, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29484733

RESUMO

Globalization, the modern lifestyle, immuno-suppressive agents, invasive surgical procedures, the loss of efficacies of existing drugs, and multidrug resistance are some of the factors used to explain the rise in fungal infections in recent years. Significant advances have been made in attempts to replace existing antifungal schedules, especially with synthetic targets. The identification of other platforms for drug discovery is now entrenched in research programs across the globe. Plants offer significant benefits owing to their numerical superiority, exceedingly broad chemical basis and appealing sustainability characteristics. Furthermore, plants have a long and rich historical association with traditional approaches towards fungal diseases. These have in numerous instances served as markers in the bioassay-guided identification of the active constituents. Although the plant family Amaryllidaceae is conventionally associated with cancer and motor-neuron disease chemotherapies, around 30 of its species have been examined for antifungal activities with microgram per millilitre inhibitory activities detected in several instances. This review focuses on the nearly 40 constituents from the family, mainly isoquinoline alkaloids, which have been screened against around 50 fungal pathogens. Encouragingly, microgram per millilitre growth inhibitory activities were applicable for several of the compounds with a minimum inhibitory concentration of 4 µg/ml seen to be the lowest.


Assuntos
Amaryllidaceae/química , Antifúngicos/uso terapêutico , Extratos Vegetais/química , Antifúngicos/farmacologia , Humanos
15.
Phytother Res ; 32(4): 625-630, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29226479

RESUMO

Scadoxus puniceus (Amaryllidaceae), a medicinal plant of high value in South Africa, is used as a component of a traditional herbal tonic prescribed to treat several ailments. Ultra-high performance liquid chromatography-tandem mass spectrometry quantified the phenolic compounds in different organs of S. puniceus. Gravity column chromatography was used to separate fractions and active compounds. The structure of these compounds was determined using 1D and 2D nuclear magnetic resonance and mass spectroscopic techniques. A microplate technique was used to determine the acetylcholinesterase inhibitory activity of the pure compounds. Metabolite profiling revealed a greater profusion of hydroxycinnamic acids (69.5%), as opposed to hydroxybenzoic acids (30.5%). Chlorogenic acid was the most abundant (49.6% of hydroxycinnamic acids) compound. In addition to chlorogenic acid, the study is the first to report the presence of sinapic, gallic, and m-hydroxybenzoic acids in the Amaryllidaceae. Chromatographic separation of S. puniceus led to the isolation of haemanthamine (1), haemanthidine (2), and a rare chlorinated amide, metolachlor (3), the natural occurrence of which is described for the first time. Haemanthamine, haemanthidine, and metolachlor displayed strong acetylcholinesterase inhibitory activity (IC50 ; 23.1, 23.7, and 11.5 µM, respectively). These results substantiate the frequent use of S. puniceus as a medicinal plant and hold much promise for further pharmaceutical development.


Assuntos
Amaryllidaceae/química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Ácidos Cumáricos/química , Ácidos Cumáricos/farmacologia , Plantas Medicinais/química , Acetamidas/química , Acetamidas/isolamento & purificação , Acetamidas/metabolismo , Acetamidas/farmacologia , Amaryllidaceae/metabolismo , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/isolamento & purificação , Alcaloides de Amaryllidaceae/metabolismo , Alcaloides de Amaryllidaceae/farmacologia , Inibidores da Colinesterase/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Ácidos Cumáricos/isolamento & purificação , Ácidos Cumáricos/metabolismo , Fenantridinas/química , Fenantridinas/isolamento & purificação , Fenantridinas/metabolismo , Fenantridinas/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologia , África do Sul , Espectrometria de Massas em Tandem
16.
Physiol Mol Biol Plants ; 24(4): 631-641, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30042618

RESUMO

Genetic diversity existing amongst five Eulophia orchid species were assessed using start codon targeted polymorphism (SCoT) and inter-retrotransposon amplified polymorphism (IRAP) markers. A total of 12 SCoT and 5 IRAP markers revealed an average of 63% genetic variability [SCoT = 63.87; IRAP = 64.95%] amongst the five Eulophia species investigated. The genetic similarities were assessed using both UPGMA and Bayesian approaches which indicated identical clustering patterns at a genetic similarity level of 50%. Analysis of molecular variance (AMOVA) revealed the presence of a significant degree of genetic variability, mostly compartmentalized within the species level. Amongst the five assessed Eulophia species, E. parviflora was the most genetically diverse representative whereas E. welwitschii was found to be least diverse based on a comparative assessment of various population genetic parameters like Nei's gene diversity (h) and Shannon's information index (I) with an overall gene flow value greater than 1. In order to evaluate the comparative marker efficiency, SCoT and IRAP marker data were subjected to various benchmark analyses like marker index, resolving power, polymorphic index content, multiplex ratio and effective multiplex ratio which revealed the robustness of both the marker techniques in assessment of genetic diversity. The present report provides the first molecular insights into the aspects of inter and intra specific genetic variability in medicinally as well as horticulturally important Eulophia species along with addressing their conservation concerns. In a nutshell, the present approach is simple, rapid and cost effective and can be extended for analysis of genetic diversity of other related plant species.

17.
Bioorg Med Chem Lett ; 27(22): 4943-4951, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-29033234

RESUMO

There is a pressing need in antibiotic drug discovery for new drugs to counterbalance the effects of multidrug resistance. Plants represent a viable platform for such endeavors owing to their traditional relevance in infectious disease therapies as well as their vast chemical resources. As many as fifty different species of the Amaryllidaceae are discernible with such functions in traditional medicine, thirty-nine of which have been subjected to pharmacological evaluations. Submicromolar antibacterial activities for several of these plants have been the driving force behind studies targeting their active constituents. This review accounts for close to a hundred of such entities, mainly isoquinoline alkaloids, which have been the focus in assays of thirty different bacterial pathogens. Promising activities were detected in several instances, although disappointingly the submicromolar level could not be breached. Also considered are structure-activity relationships which have emerged within the various groups of Amaryllidaceae alkaloids.


Assuntos
Amaryllidaceae/química , Antibacterianos/química , Alcaloides/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Amaryllidaceae/metabolismo , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Extratos Vegetais/química
18.
J Nat Prod ; 80(4): 1020-1027, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28248501

RESUMO

A hyphenated procedure involving high-performance liquid chromatography, photodiode array detection, high-resolution mass spectrometry, solid-phase extraction, and nuclear magnetic resonance spectroscopy, i.e., HPLC-PDA-HRMS-SPE-NMR, has proven an effective technique for the identification of compounds in complex matrices. Most HPLC-PDA-HRMS-SPE-NMR investigations reported so far have relied on analytical-scale reversed-phase C18 columns for separation. Herein is reported the use of an analytical-scale pentafluorophenyl column as an orthogonal separation method following fractionation of a crude ethyl acetate extract of leaves of Coleonema album on a preparative-scale C18 column. This setup allowed the HPLC-PDA-HRMS-SPE-NMR analysis of 23 coumarins, including six new compounds, 8-O-ß-d-glucopyranosyloxy-6-(2,3-dihydroxy-3-methylbut-1-yl)-7-methoxycoumarin (4), (Z)-6-(4-ß-d-glucopyranosyloxy-3-methylbut-2-en-1-yl)-7-hydroxycoumarin (6), 6-(4-ß-d-glucopyranosyloxy-3-methylbut-1-yl)-7-hydroxycoumarin (8), (Z)-7-(4-ß-d-glucopyranosyloxy-3-methylbut-2-en-1-yloxy)coumarin (13), (S)-8-(3-chloro-2-hydroxy-3-methylbut-1-yloxy)-7-methoxycoumarin (19), and 7-(3-chloro-2-hydroxy-3-methylbut-1-yloxy)coumarin (20). The use of the pentafluorophenyl column even allowed separation of several regioisomers that are usually difficult to separate using reversed-phase C18 columns. The phytochemical investigation described for C. album in this report demonstrates the potential and wide applicability of HPLC-PDA-HRMS-SPE-NMR for accelerated structural identification of natural products in complex mixtures.


Assuntos
Cumarínicos/análise , Umbeliferonas/análise , Cromatografia Líquida de Alta Pressão/métodos , Cumarínicos/química , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Extratos Vegetais/química , Rutaceae/química , Extração em Fase Sólida , África do Sul , Umbeliferonas/química , Umbeliferonas/isolamento & purificação
19.
Phytother Res ; 31(5): 713-720, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28217929

RESUMO

Cryptostephanus vansonii I. Verd., an endemic Amaryllidaceae species from Zimbabwe, was evaluated for its acetylcholinesterase (AChE) inhibitory and cytotoxicity properties using Ellman's colorimetric method and the tetrazolium-based colorimetric assay against Vero monkey kidney cells, respectively. The plant extracts were also evaluated for their antibacterial activity against five bacteria. Furthermore, phytochemical profiles of the extracts were determined using ultra-high performance liquid chromatography coupled with tandem mass spectrometry analysis. A plant part-dependent AChE inhibitory activity was observed, in the order, root > rhizome > basal leaf > leaf. Overall, C. vansonii extracts exhibited better antibacterial activity against Gram-negative compared with Gram-positive bacteria. Cytotoxic effects were not detected in Vero monkey kidney cell lines suggesting the possible absence of toxophores in C. vansonii extracts. Similar to the trend in biological activity, a distinct plant part-dependent variation in hydroxybenzoates, hydroxycinnamates and flavonoids was observed in the plant extracts. In addition, 5-hydroxymetylfurfural and eucomic acid were detected in the different plant parts of C. vansonii. The results of the present study provide valuable AChE inhibition activity, toxicological and phytochemical profiles of C. vansonii. Further studies on isolation of bioactive compounds and their subsequent evaluation in other pharmacological and toxicological model systems are required. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Inibidores da Colinesterase/farmacologia , Liliaceae/química , Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Flavonoides/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química
20.
Pharm Biol ; 55(1): 1249-1255, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28262031

RESUMO

CONTEXT: Coleonema album (Thunb) Bart. & H. L. Wendl (Rutaceae) has been used in the formulation of skincare products, and the Khoisan people rub it on their skin to add luster. Coleonema pulchellum I. Williams has received less attention in the South African traditional medicine. OBJECTIVE: This study investigates the antifungal and antioxidant activities of C. album and C. pulchellum essential oil (EO) and leaf extracts; and analyzes the chemical components of their EOs. MATERIALS AND METHODS: Antifungal activity of leaf extracts was determined using the microdilution method with griseofulvin and ketoconazole as controls. Antifungal capacity of EO was investigated using the 'Volatile release plate method'. Trichophyton rubrum (ATCC 28188) and T. mentagrophytes (ATCC 9533) mycelia (0.3 cm diameter) were placed on fresh yeast malt agar in Petri dishes with filter paper (impregnated with 20 µL of EO) on the lid for direct exposure to EO volatiles while plates without EO were used as controls. The incubation time was seven days. Antioxidant activities of the leaf extracts were determined. RESULTS: Methanol leaf extract of C. pulchellum inhibited the growth of three fungi tested with MIC values of 195, 391 and 49 µg/mL for Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum gypseum, respectively. Terpenes formed the major components of the EO. The EO from both plants inhibited the growth of T. rubrum in vitro. DISCUSSION AND CONCLUSION: This study revealed the therapeutic value of C. pulchellum. Coleonema album and C. pulchellum should be considered as potential plants for skin ointment from natural origin.


Assuntos
Antifúngicos/isolamento & purificação , Antioxidantes/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Rutaceae , Dermatopatias , Antifúngicos/administração & dosagem , Antioxidantes/administração & dosagem , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/isolamento & purificação , Humanos , Extratos Vegetais/administração & dosagem , Folhas de Planta , Dermatopatias/tratamento farmacológico , Dermatopatias/metabolismo , Dermatopatias/microbiologia , Trichophyton/efeitos dos fármacos , Trichophyton/fisiologia
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