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Gonzalez-Pastor R, Carrera-Pacheco SE, Zúñiga-Miranda J, Rodríguez-Pólit C, Mayorga-Ramos A, Guamán LP, Barba-Ostria C. Current Landscape of Methods to Evaluate Antimicrobial Activity of Natural Extracts. Molecules 2023; 28:molecules28031068. [PMID: 36770734 PMCID: PMC9920787 DOI: 10.3390/molecules28031068] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/24/2023] Open
Abstract
Natural extracts have been and continue to be used to treat a wide range of medical conditions, from infectious diseases to cancer, based on their convenience and therapeutic potential. Natural products derived from microbes, plants, and animals offer a broad variety of molecules and chemical compounds. Natural products are not only one of the most important sources for innovative drug development for animal and human health, but they are also an inspiration for synthetic biology and chemistry scientists towards the discovery of new bioactive compounds and pharmaceuticals. This is particularly relevant in the current context, where antimicrobial resistance has risen as a global health problem. Thus, efforts are being directed toward studying natural compounds' chemical composition and bioactive potential to generate drugs with better efficacy and lower toxicity than existing molecules. Currently, a wide range of methodologies are used to analyze the in vitro activity of natural extracts to determine their suitability as antimicrobial agents. Despite traditional technologies being the most employed, technological advances have contributed to the implementation of methods able to circumvent issues related to analysis capacity, time, sensitivity, and reproducibility. This review produces an updated analysis of the conventional and current methods to evaluate the antimicrobial activity of natural compounds.
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Affiliation(s)
- Rebeca Gonzalez-Pastor
- Biomedical Research Center (CENBIO), Eugenio Espejo School of Health Sciences, Universidad UTE, Quito 170527, Ecuador
| | - Saskya E. Carrera-Pacheco
- Biomedical Research Center (CENBIO), Eugenio Espejo School of Health Sciences, Universidad UTE, Quito 170527, Ecuador
| | - Johana Zúñiga-Miranda
- Biomedical Research Center (CENBIO), Eugenio Espejo School of Health Sciences, Universidad UTE, Quito 170527, Ecuador
| | - Cristina Rodríguez-Pólit
- Biomedical Research Center (CENBIO), Eugenio Espejo School of Health Sciences, Universidad UTE, Quito 170527, Ecuador
| | - Arianna Mayorga-Ramos
- Biomedical Research Center (CENBIO), Eugenio Espejo School of Health Sciences, Universidad UTE, Quito 170527, Ecuador
| | - Linda P. Guamán
- Biomedical Research Center (CENBIO), Eugenio Espejo School of Health Sciences, Universidad UTE, Quito 170527, Ecuador
- Correspondence: (L.P.G.); (C.B.-O.)
| | - Carlos Barba-Ostria
- School of Medicine, College of Health Sciences, Universidad San Francisco de Quito (USFQ), Quito 170901, Ecuador
- Correspondence: (L.P.G.); (C.B.-O.)
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da Silva PR, do Carmo Alves de Lima M, Souza TP, Sandes JM, da Conceição Alves de Lima A, Neto PJR, Dos Santos FAB, Alves LC, da Silva RMF, de Moraes Rocha GJ, da Cruz Filho IJ. Lignin from Morinda citrifolia leaves: Physical and chemical characterization, in vitro evaluation of antioxidant, cytotoxic, antiparasitic and ultrastructural activities. Int J Biol Macromol 2021; 193:1799-1812. [PMID: 34774863 DOI: 10.1016/j.ijbiomac.2021.11.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/20/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
In this work, we investigated in vitro the antioxidant, cytotoxic and anti-leishmanial activities of a lignin extracted from the leaves of Morinda citrifolia. Initially, an analysis of the composition of the sheets was performed, then the lignin was obtained by alkaline delignification and characterized by different techniques: elemental analysis, FT-R, UV-vis, HSQC-NMR, thermal analysis, Py-GC/MS and by GPC. The results showed that the leaves had in their composition cellulose (31.29%), hemicellulose (25.01%), lignin (18.34%), extractives (14.39%) and ash (10.03%). The lignin extraction yield was 89.8%. The lignin obtained is of the GSH type with the following contents 79.39%, 13.58% and 7.03% respectively. Furthermore, it is low molecular weight and thermally stable. It had a phenolic content of 93.3 mg GAE/g and low antioxidant activity. In macrophage cytotoxicity assays, it presented a CC50 of 31.0 μg/mL, showing less toxicity than amphotericin B. In assays against the promastigote forms of Leishmania amazonensis, lignin presented an IC50 of 29.56 μg/mL, a less effective concentration than amphotericin B (IC50 = 0.14 μg/mL). However, it was able to promote inhibition of the parasites, a fact confirmed by structural changes. These findings reinforce that M. citrifolia lignin is a promising macromolecule for use as an antiparasitic and antioxidant agent.
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Affiliation(s)
- Paula Roberta da Silva
- Federal University of Pernambuco, Department of Antibiotics, Biosciences Center, 50.670-420 Recife, PE, Brazil
| | | | - Thammyris Pires Souza
- Federal University of Pernambuco, Department of Antibiotics, Biosciences Center, 50.670-420 Recife, PE, Brazil
| | - Jana Messias Sandes
- Aggeu Magalhães Institute, Oswaldo Cruz Foundation (IAM-FIOCRUZ), 50670-420 Recife, PE, Brazil
| | | | - Pedro José Rolim Neto
- Federal University of Pernambuco, Department of Pharmacia, Health Sciences Center, 50.670-420 Recife, PE, Brazil
| | | | - Luiz Carlos Alves
- Aggeu Magalhães Institute, Oswaldo Cruz Foundation (IAM-FIOCRUZ), 50670-420 Recife, PE, Brazil
| | | | - George Jackson de Moraes Rocha
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Center for Research in Energy and Materials (CNPEM), Polo II de Alta Tecnologia, Rua Giuseppe Máximo Scolfaro, 10.000, PO Box 6192, 13083-100 Campinas, SP, Brazil.
| | - Iranildo José da Cruz Filho
- Federal University of Pernambuco, Department of Antibiotics, Biosciences Center, 50.670-420 Recife, PE, Brazil
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Tedeschi LO, Muir JP, Naumann HD, Norris AB, Ramírez-Restrepo CA, Mertens-Talcott SU. Nutritional Aspects of Ecologically Relevant Phytochemicals in Ruminant Production. Front Vet Sci 2021; 8:628445. [PMID: 33748210 PMCID: PMC7973208 DOI: 10.3389/fvets.2021.628445] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/04/2021] [Indexed: 12/14/2022] Open
Abstract
This review provides an update of ecologically relevant phytochemicals for ruminant production, focusing on their contribution to advancing nutrition. Phytochemicals embody a broad spectrum of chemical components that influence resource competence and biological advantage in determining plant species' distribution and density in different ecosystems. These natural compounds also often act as plant defensive chemicals against predatorial microbes, insects, and herbivores. They may modulate or exacerbate microbial transactions in the gastrointestinal tract and physiological responses in ruminant microbiomes. To harness their production-enhancing characteristics, phytochemicals have been actively researched as feed additives to manipulate ruminal fermentation and establish other phytochemoprophylactic (prevent animal diseases) and phytochemotherapeutic (treat animal diseases) roles. However, phytochemical-host interactions, the exact mechanism of action, and their effects require more profound elucidation to provide definitive recommendations for ruminant production. The majority of phytochemicals of nutritional and pharmacological interest are typically classified as flavonoids (9%), terpenoids (55%), and alkaloids (36%). Within flavonoids, polyphenolics (e.g., hydrolyzable and condensed tannins) have many benefits to ruminants, including reducing methane (CH4) emission, gastrointestinal nematode parasitism, and ruminal proteolysis. Within terpenoids, saponins and essential oils also mitigate CH4 emission, but triterpenoid saponins have rich biochemical structures with many clinical benefits in humans. The anti-methanogenic property in ruminants is variable because of the simultaneous targeting of several physiological pathways. This may explain saponin-containing forages' relative safety for long-term use and describe associated molecular interactions on all ruminant metabolism phases. Alkaloids are N-containing compounds with vast pharmacological properties currently used to treat humans, but their phytochemical usage as feed additives in ruminants has yet to be exploited as they may act as ghost compounds alongside other phytochemicals of known importance. We discussed strategic recommendations for phytochemicals to support sustainable ruminant production, such as replacements for antibiotics and anthelmintics. Topics that merit further examination are discussed and include the role of fresh forages vis-à-vis processed feeds in confined ruminant operations. Applications and benefits of phytochemicals to humankind are yet to be fully understood or utilized. Scientific explorations have provided promising results, pending thorough vetting before primetime use, such that academic and commercial interests in the technology are fully adopted.
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Affiliation(s)
- Luis O. Tedeschi
- Department of Animal Science, Texas A&M University, College Station, TX, United States
| | - James P. Muir
- Texas A&M AgriLife Research, Stephenville, TX, United States
| | - Harley D. Naumann
- Division of Plant Sciences, University of Missouri, Columbia, MO, United States
| | - Aaron B. Norris
- Department of Natural Resources Management, Texas Tech University, Lubbock, TX, United States
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Anderson O, Beckett J, Briggs CC, Natrass LA, Cranston CF, Wilkinson EJ, Owen JH, Mir Williams R, Loukaidis A, Bouillon ME, Pritchard D, Lahmann M, Baird MS, Denny PW. An investigation of the antileishmanial properties of semi-synthetic saponins. RSC Med Chem 2020; 11:833-842. [PMID: 33479679 PMCID: PMC7651632 DOI: 10.1039/d0md00123f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/21/2020] [Indexed: 12/25/2022] Open
Abstract
Leishmaniasis is a neglected tropical disease caused by insect-vector borne protozoan parasites of the, Leishmania species. Whilst infection threatens and affects millions of the global poor, vaccines are absent and drug therapy limited. Extensive efforts have recently been made to discover new leads from small molecule synthetic compound libraries held by industry; however, the number of new chemical entities identified and entering development as anti-leishmanials has been very low. This has led to increased interest in the possibility of discovering naturally derived compounds with potent antileishmanial activity which may be developed towards clinical applications. Plant-derived triterpenoid and steroidal saponins have long been considered as anti-microbials and here we describe an investigation of a library of 137 natural (9) and semi-synthetic saponins (128) for activity against Leishmania mexicana, a causative agent of cutaneous leishmaniasis. The triterpenoid sapogenin, hederagenin, readily obtained in large quantities from Hedera helix (common ivy), was converted into a range of 128 derivatives. These semi-synthetic compounds, as well as saponins isolated from ivy, were examined with a phenotypic screening approach to identify potent and selective anti-leishmanial hits. This led to the identification of 12 compounds, including the natural saponin gypsogenin, demonstrating high potency (ED50 < 10.5 μM) against axenic L. mexicana amastigotes, the mammalian pathogenic form. One of these, hederagenin disuccinate, was sufficiently non-toxic to the macrophage host cell to facilitate further analyses, selectivity index (SI) > 10. Whilst this was not active in an infected cell model, the anti-leishmanial properties of hederagenin-derivatives have been demonstrated, and the possibility of improving the selectivity of natural hederagenin through chemical modification has been established.
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Affiliation(s)
- Orlagh Anderson
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Joseph Beckett
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Carla C Briggs
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Liam A Natrass
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
- Department of Chemistry and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK
| | - Charles F Cranston
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
| | - Elizabeth J Wilkinson
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Jack H Owen
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Rhodri Mir Williams
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Angelos Loukaidis
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Marc E Bouillon
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Deiniol Pritchard
- Naturiol Bangor Ltd , Alun Roberts Building , Bangor University , Gwynedd LL57 2UW , UK
| | - Martina Lahmann
- Department of Chemistry , School of Natural Science , Bangor University , Gwynedd LL57 2UW , UK
| | - Mark S Baird
- Naturiol Bangor Ltd , Alun Roberts Building , Bangor University , Gwynedd LL57 2UW , UK
| | - Paul W Denny
- Department of Biosciences and Centre for Global Infectious Diseases , Durham University , Stockton Road , Durham , DH1 3LE , UK . ; Tel: +44 (0)191 3343983
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