How to Study Antimicrobial Activities of Plant Extracts: A Critical Point of View

Author(s):  
Séverine Mahieux ◽  
Maria Susana Nieto-Bobadilla ◽  
Isabelle Houcke ◽  
Christel Neut
2010 ◽  
Vol 5 (2) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Maria Graça Miguel ◽  
Cláudia Cruz ◽  
Leonor Faleiro ◽  
Mariana T. F. Simões ◽  
Ana Cristina Figueiredo ◽  
...  

The essential oils from Foeniculum vulgare commercial aerial parts and fruits were isolated by hydrodistillation, with different distillation times (30 min, 1 h, 2 h and 3 h), and analyzed by GC and GC-MS. The antioxidant ability was estimated using four distinct methods. Antibacterial activity was determined by the agar diffusion method. Remarkable differences, and worrying from the quality and safety point of view, were detected in the essential oils. trans-Anethole (31-36%), α-pinene (14-20%) and limonene (11-13%) were the main components of the essentials oil isolated from F. vulgare dried aerial parts, whereas methyl chavicol (= estragole) (79-88%) was dominant in the fruit oils. With the DPPH method the plant oils showed better antioxidant activity than the fruits oils. With the TBARS method and at higher concentrations, fennel essential oils showed a pro-oxidant activity. None of the oils showed a hydroxyl radical scavenging capacity >50%, but they showed an ability to inhibit 5-lipoxygenase. The essential oils showed a very low antimicrobial activity. In general, the essential oils isolated during 2 h were as effective, from the biological activity point of view, as those isolated during 3 h.


RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2804-2837
Author(s):  
Chhangte Vanlalveni ◽  
Samuel Lallianrawna ◽  
Ayushi Biswas ◽  
Manickam Selvaraj ◽  
Bishwajit Changmai ◽  
...  

Herein, we have reviewed new findings in the research domain of the green synthesis of silver nanoparticles using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015.


2022 ◽  
Vol 12 (2) ◽  
pp. 790
Author(s):  
Mihaela Adriana Tița ◽  
Maria Adelina Constantinescu ◽  
Ovidiu Tița ◽  
Endre Mathe ◽  
Loreta Tamošaitienė ◽  
...  

(1) Background: The demand for healthy and nutritious food is growing worldwide. Fermented dairy products are highly valued by consumers for their health benefits. Kefir is a fermented dairy product that brings many benefits to the consumer due to its antioxidant, anticancer, antidiabetic, antihypertensive and antimicrobial properties. Extracts from various plants in the form of volatile oils have a beneficial efct on consumer health. their antioxidant and antimicrobial activities were demonstrated. (2) Methods: In the present study, the main purpose was to obtain a fermented dairy product with a high nutritional value; therefore, kefir, enriched with three types of volatile oils, namely, volatile mint oil, volatile fennel oil and volatile lavender oil, was made. The kefir samples obtained were sensory and texturally analyzed. The beneficial effect on health must also be studied in terms of the acceptability of these products by consumers from a sensory point of view. A non-numerical method based on several multi-personal approval criteria was used to interpret the results obtained in the sensory analysis. In the textural analysis, the consistency, cohesiveness and firmness of the kefir samples were analyzed. (3) Results: The samples enriched with volatile oils obtained superior results compared to the control sample in both conducted examinations. Kefir samples with volatile oils retained their sensory and textural characteristics for a longer time during storage. (4) Conclusions: The volatile oils added to kefir positively influenced the sensory and textural characteristics of the finished product.


Author(s):  
Rossana Morabito ◽  
Laura Cornara ◽  
Giuseppina La Spada ◽  
Angela Marino ◽  
Gian Luigi Mariottini ◽  
...  

Some species of Cnidarians, well known venomous organisms, are able to induce serious health problems as well as economic and social trouble. A lot of data show that cnidarian venoms can be cytotoxic to cultured cells. Therefore, a priority of the research is to find tools which could counteract the damaging activity of venoms. In this connection, the modulatory effects exerted by extracts of plants Ananas comosus (L.) and Carica papaya (L.) on cytotoxicity of heterotrichous microbasic eurytele nematocysts isolated from the jellyfish Pelagia noctiluca was evaluated. The nematocyst extract induced strong cytotoxicity at highest tested doses with reduction of cell survival below 40% and IC50 value of 40×103 nematocysts/mL. Both plant extracts significantly improved the survival of cells, so that the IC50 resulted 74×103 and 100×103 nematocysts/mL in the presence of A. comosus and C. papaya extracts, respectively, both used at 10 and 100 μg/mL. Taking into account that heterotrichous microbasic eurytele nematocysts are present mainly in tentacles, which Pelagia noctiluca utilizes both for predation and defence, this result is particularly interesting from both ecological and sanitary point of view and demonstrates the potential of these plants extracts against cnidarian venoms.


2020 ◽  
Vol 21 (2) ◽  
pp. 1-12
Author(s):  
Mhuji Kilonzo ◽  
Chrispinus Rubanza ◽  
Upendo Richard ◽  
Gideon Sangiwa

Background: Medicinal plants have been of great value to human healthcare in most parts of the world for thousands of years. In Tanzania, over 12,000 species of higher plants have been reported, and about 10% are estimated to be used as medicines to treat different human health conditions. The present study aimed to determine in vitro antimicrobial activities and phytochemical analysis of Ormocarpum trichocarpum and Euclea divinorum which are commonly used as a traditional medicine in Tanzania. Methods: Minimum Inhibitory Concentration (MIC) of plants extracts against tested bacterial and fungal species were determined using 96 wells microdilution method. In this method, 50 μL of nutrient and saboraud’s dextrose broth for bacteria and fungus respectively were loaded in each well followed by 50 μL of extract to make final volume of 100 μL. Subsequently 50 μL were transferred from first rows of each well to the second rows and the process was repeated down the columns to the last wells from which 50 μL were discarded. Thereafter, 50 μL of the selected bacterial and fungal suspension was added to each well thus making final volume of 100μL. The lowest concentration which showed no microbe growth was considered as MIC. The study also evaluated phytochemical compounds present in the ethyl acetate extracts from O. trichocarpum stem bark and E. divinorum root bark extract using Gas Chromatography-Mass Spectrometry (GC-MS) technique. Results: It was revealed that 66% of the tested microbes were susceptible to plant extracts at MIC value of 0.39 mg/mL whereas 83% being susceptible to extracts at MIC value of 0.781 mg/mL. Interestingly, four out of 18 tested plant extracts exhibited high antifungal activity below that of the standard antifungal drug, fluconazole. The GC-MS analysis revealed the presence of various low molecular weight phytochemicals which belongs to six groups of secondary metabolites namely dieterpenes, alphatic hydrocarbons, tetraterpenes, sesquiterpenes, steroid and triterpenes. Conclusion: It was concluded that the presence of various phytochemicals in the tested plant extracts may be associated with pharmacological properties of O. trichocarpum and E. divinorum and therefore justifying ethnomedical usage of such plants.   Keywords: Antibacterial, antifungal, Ormocarpum trichocarpum, Euclea divinorum


Tempo ◽  
1954 ◽  
pp. 19-25
Author(s):  
John S. Weissmann

The news that Halsey Stevens, an American University professor, was preparing a book on Bartók, aroused keen interest among sympathisers with the Hungarian composer, and publication-date was impatiently awaited. The author received very generous assistance from every quarter: a research grant from his university, and direct and indirect material information from a large number of people most of whose help is duly acknowledged in the preface. Why was it, then, that the book did not come up to expectations? The answer lies, partly, in Prof. Stevens's self-imposed limitations. The title says: “The Life and Music of Béla Bartók”, and Prof. Stevens seems to be careful to confine himself, almost literally, to the description of the two points his title indicates. His aims are more clearly defined in the foreword, where he says: “This book is concerned primarily with Bartók's music, approached from both the analytical and the critical point of view” (though the latter point of view is rather tentatively approached), and in a passage later on in the book: “… it has nowhere been the intention in this book to examine Bartók's work from the standpoint of its motivations, physical, psychological, or otherwise …” (p.250). I submit that this approach, though conducive of valuable information, is essentially a wrong one to adopt.


2003 ◽  
Vol 37 (4) ◽  
Author(s):  
E. Cornelius

The revelation of God – a rhetorical-critical interpretation of Romans 1:18-32 M.A. Kruger’s 1983 doctoral thesis caused serious discussion in GKSA circles with regard to the differentiation between “general revelation” and “specific revelation”. Romans 1:18-32 seems to be a central pericope in the understanding of the revelation of God. A project of the Faculty of Theology, PU for CHE, focusing on this specific problem, gave birth to this article as a component of the interpretation of this pericope. The issue addressed in this article is how this pericope can be interpreted from a rhetorical-critical point of view. In my own interdisciplinary and interactional approach to rhetorical criticism, the purpose is to interpret the communicative function(s) of this pericope. It turns out that the letter to the Romans was addressed to those in Rome in order to convince them that the reason for their acceptance as God’s people lies in God’s work only and not in their imitation of the Jews. Romans 1:18-32 seems to be part of the opening of the letter body intended to be a warning for all people, including an example of what may happen if this warning is not taken seriously. The logic of the argument indicates that God’s wrath will come upon those who do not accept His revelation in creation.


Chemosphere ◽  
2020 ◽  
Vol 257 ◽  
pp. 127114
Author(s):  
Isabela C.F. Vasques ◽  
Fernando B. Egreja Filho ◽  
Everton G. Morais ◽  
Francielle R.D. Lima ◽  
Jakeline R. Oliveira ◽  
...  

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