scholarly journals Evaluation of the Phenolic Profile of Castanea sativa Mill. By-Products and Their Antioxidant and Antimicrobial Activity against Multiresistant Bacteria

Antioxidants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 87 ◽  
Author(s):  
Vanessa Silva ◽  
Virgílio Falco ◽  
Maria Inês Dias ◽  
Lillian Barros ◽  
Adriana Silva ◽  
...  

The chestnut industry generates a large amount of by-products. These agro-industrial wastes have been described as potential sources of phenolic compounds with high bioactive potential. Therefore, we aimed to extract the phenolic compounds from chestnut by-products and assess their antioxidant potential and evaluate their antimicrobial activity against multidrug resistant bacteria. The individual phenolic compounds in the ethanolic extracts of chestnut shell, inner shell, bur, and leaves were characterized by HPLC-DAD/electrospray ionization (ESI)-MS. The antioxidant properties were determined by DPPH and ABTS assays. The minimum inhibitory concentration (MIC) and the antimicrobial susceptibility was performed using the Kirby–Bauer disc diffusion method against 10 bacterial strains. The major phenolic compounds identified in the extracts were trigalloyl-HHDP-glucose, gallic acid, quercetin, and myricetin glycoside derivatives. All chestnut by-products presented promising antioxidant activity in both assays, with leaf samples the ones presenting the highest antioxidant capacity. The inner shell’s extract was effective against all Gram-positive and two Gram-negative bacteria; nevertheless, all extracts showed antibacterial activity. Staphylococcus epidermidis showed susceptibility to all extracts while none of the extracts was able to suppress the growth of Escherichia coli and Salmonella enteritidis. Chestnut by-products are a source of phenolic compounds with prominent antioxidant and antimicrobial activities. Nevertheless, further studies should be conducted to assess the correlation between phenolic compounds and the bioactivities obtained.

Proceedings ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 18
Author(s):  
Jessica Ribeiro ◽  
Vanessa Silva ◽  
Alfredo Aires ◽  
Rosa Carvalho ◽  
Gilberto Igrejas ◽  
...  

Multidrug-resistant bacteria are a significant threat to public health and new classes of antibiotics and approaches to treatment are needed. Several studies have shown that natural plant-derived compounds could be a promising mean to fight microbial resistance but only a few were conducted with antibiotic resistant bacteria. Therefore, the aim of this study was to extract phenolic compounds from the leaves, fruits, and tree trunk of Platanus hybrida and evaluate their antimicrobial activity against antibiotic resistant bacterial strains. The polyphenolic compounds were extracted using a water/ethanol (20:80) mixture. Two grams of powder of each sample was extracted with 100 mL of solvent by stirring for 2h. The extracts were redissolved in dimethyl sulfoxide (DMSO) to a final concentration of 100 mg/mL. An antimicrobial susceptibility assay was performed using the Kirby–Bauer disc diffusion method and was tested against ten different bacteria: Listeria monocytes, Bacillus cereus, Enterococcus faecium, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Salmonella enteritidis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. The fruits had the highest antibacterial activity showing a minimum inhibitory concentration (MIC) of 10mg/mL, contrary to the tree trunk that showed the lowest antibacterial activity. None of the extracts showed antimicrobial properties against S. enteritidis, E. faecium and E. faecalis. These results show that P. hybrida’s phenolic compounds act as antibacterial agents, which may become useful therapeutic tools and represent a source for the development of novel antimicrobials. However, they were not effective against all bacteria, which shows that polyphenols alone might not substitute antibiotics.


2009 ◽  
Vol 59 (4) ◽  
pp. 463-472 ◽  
Author(s):  
Aysel Ugur ◽  
Nurdan Sarac ◽  
Ozgur Ceylan ◽  
M. Duru

Chemical composition of endemicCentaurea austro-anatolicaand studies of its antimicrobial activity against multi-resistant bacteriaHexane, chloroform, ethyl acetate and ethanolic extracts of the aerial parts ofCentaurea austro-anatolicaHub.-Mor. (Asteraceae) were evaluated against microorganisms, including multiresistant bacteria, using a paper disc diffusion method. The chloroform extract exhibited significant antibacterial activity toward all bacteria tested. The chemical composition of the chloroform extract was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The major compounds of the extract were caryophyllene oxide (21.32 %), spathulenol (10.86 %),n-tricosanol (9.58 %) and geranyl isovalerate (8.71 %).


2020 ◽  
Vol 21 (3) ◽  
Author(s):  
Magdalena Woźniak ◽  
Lucyna Mrówczyńska ◽  
Anna Sip ◽  
Marta Babicka ◽  
Tomasz Rogoziński ◽  
...  

Introduction. Honey, propolis and pollen belong to bee products that have beneficial biological properties. These products exhibit e.g. antibacterial, antifungal and antioxidant properties. Due to biological activity and natural origin, bee products are used, e.g. in the food industry, cosmetology and pharmacy. Aim. The aim of the study was to compare the antioxidant and antibacterial activity of honey, propolis and pollen from an apiary located in Wielkopolska Province. Material and methods. Honey, propolis and pollen used in this study came from the same apiary located in Wielkopolska Province. The antioxidant potential of bee products was evaluated applying DPPH· free radical scavenging activity assay. The antimicrobial activity of the tested bee products was determined by the point-diffusion method against 13 strains of pathogenic and potentially pathogenic bacteria. In addition, the total content of phenolic compounds in honey, propolis and pollen was determined by the colorimetric method. Results. Propolis exhibited higher antioxidant activity, in comparison to honey and pollen. The antiradical activity of propolis was equal to 80% approx. activity of Trolox, the standard antioxidant. Among tested bee products, propolis was characterized by the highest total phenols content. In addition, honey, propolis and pollen showed antagonistic activity against tested bacterial strains. Conclusions. The obtained results indicate that among the tested bee products of native origin, i.e. honey, propolis and pollen, propolis characterized by the highest antioxidant activity and the total content of phenolic compounds. In addition, all bee products showed bactericidal activity against the tested bacterial strains.


2019 ◽  
Vol 79 (3) ◽  
pp. 452-459 ◽  
Author(s):  
F. R. G. Silva ◽  
T. M. S. Matias ◽  
L. I. O. Souza ◽  
T. J. Matos-Rocha ◽  
S. A. Fonseca ◽  
...  

Abstract The study aimed to evaluate the antimicrobial activity, antioxidant, toxicity and phytochemical screening of the Red Propolis Alagoas. Antimicrobial activity was evaluated by disk diffusion method. Determination of antioxidant activity was performed using the DPPH assay (1.1-diphenyl-2-picrylhydrazyl), FTC (ferric thiocyanate) and determination of phenolic compounds by Follin method. Toxicity was performed by the method of Artemia salina and cytotoxicity by MTT method. The phytochemical screening for the detection of allelochemicals was performed. The ethanol extract of propolis of Alagoas showed significant results for antimicrobial activity, and inhibitory activity for Staphylococcus aureus and Candida krusei. The antioxidant activity of the FTC method was 80% to 108.3% hydrogen peroxide kidnapping, the DPPH method showed an EC50 3.97 mg/mL, the content of total phenolic compounds was determined by calibration curve gallic acid, resulting from 0.0005 mg/100 g of gallic acid equivalent. The extract was non-toxic by A. salina method. The propolis extract showed high activity with a higher percentage than 75% inhibition of tumor cells OVCAR-8, SF-295 and HCT116. Chemical constituents were observed as flavonones, xanthones, flavonols, and Chalcones Auronas, Catechins and leucoanthocyanidins. It is concluded that the extract can be tested is considered a potential source of bioactive metabolites.


2010 ◽  
Vol 7 (3) ◽  
pp. 1159-1165
Author(s):  
Baghdad Science Journal

The antimicrobial activity of ginger extracts ( cold-water, hot-water, ethanolic and essential oil ) against some of pathogenic bacteria ( Escherichia coli , Salmonella sp , Klebsiella sp , Serratia marcescens, Vibrio cholerae , Staphylococcus aureus , Streptococcus sp) was investigated using Disc diffusion method , and the results were compared with the antimicrobial activity of 12 antibiotics on the same bacteria . The results showed that the ginger extracts were more effective on gram-positive bacteria than gram-negative . V. cholerae and S. marcescens,were the most resistant bacteria to the extracts used , while highest inhibition was noticed against Streptococcus sp (28 mm) . The ethanolic extract showed the broadest antibacterial activity ( 11 to 28 mm ) , in comparison with moderate activity of essential oil , it was observed that the cold-water extract was more effective on the bacteria than hot-water extract . Ginger ethanolic extract presented higher diameter of inhibition zone for Streptococcus sp than in Ciprofloxacin , Cefotaxime , Cefalotin , Cephalexin and Cephaloridine , also it was found a similarity between the higher inhibition zones of ethanolic extract of ginger and some antibiotics for S. aureus , E. coli , Salmonella sp and Klebsiella sp . V. cholerae and S. marcescens,also highly resistant to antibiotics . Phytochemical analysis of ethanolic extract of ginger revealed the present of glycosides, terpenoids, flavonids and phenolic compounds


2016 ◽  
Vol 6 (2) ◽  
pp. 70-76
Author(s):  
Soumia Keddari ◽  
Narimen Benaoum ◽  
Yasmina Mokhtaria Boufadi ◽  
Mansouria Belhocine ◽  
Ali Riazi

Medicinal plants have been used for countries as cures for human diseases because they contain components of therapeutic value. Among these medi-cinal plants, Ammi visnage which have an immense reservoir of potential compounds attributed to the secondary metabolites which have the advan-tage of being of great diversity of chemical structure and have a very wide range of biological activities. The objectives of the present work were to stu-dy the antioxidant and antimicrobial activity of phenolic compounds ex-tracted from A. visnaga L. Its extraction is performed by two methods, etha-nol extraction and water extraction. The results showed that A. visnaga L.. ethanolic extract contains a mixture of phytochemical classes as polyphenol, flavonoids and revealed that this plant has high antioxidant activity (IC50 0.069 mg/ml). Regarding the antimicrobial activity results expressed by the diameter of the inhibition zones by diffusion method AWDT, the most signifi-cant inhibition was observed against to Staphylococcus aureus (12 mm) to the ethanol extract at concentration of 100mg / ml. Thus the aqueous ex-tract had a significant inhibitory activity against on the strains Staphylococ-cus aureus (8 mm), E. coli ATCC 10536 (8 mm) to a concentration of 100 mg / ml. The results for the antibacterial properties have shown that Gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes and M. luteus.) were more sensitive than gram-negative (Pseudomonas aeruginosa, E. coli ATCC 10536) against from the action of phenolic compounds of the Ammi visnaga ethanolic extract.


2020 ◽  
Author(s):  
◽  
David Serunjogi ◽  
Kizito Muwonge

Background: Plant species such as the guava have been used in Uganda and elsewhere in the world to treat some of the medical conditions associated with bacteria, this is due to the increased number of drug resistant bacteria in the world. In this study, the antimicrobial activity of guava leaf extracts against some of the disease causing bacteria isolated from Kisubi hospital in Uganda is discussed. Methods: The guava leafs were collected from a plantation near Zika forest in Uganda (0°7′27″N 32°31′32″E / 0.12417°N 32.52556°E / 0.12417; 32.52556) and samples were put in a bag and transferred to the university laboratory where they were identified. The extracts were obtained by maceration using distilled water, 30%, 50% and 70 % methanol as the extraction solvents. Antimicrobial susceptibility testing was conducted using the disc diffusion method. Results: Gram-negative Escherichia coli was sensitive to the plant extract and synthetic commercial drugs such as trimethoprim-sulfamethozole, ciprofloxacin, and Gentamicin. Pseudomonas aeruginosa was resistant to all drugs. Streptococcus pneumonia and Staphylococcus aureus were all sensitive to the plant extracts with measurable inhibition zones. Conclusion: The Guava tree leaf crude extracts have antimicrobial activity against drug-resistant bacteria. More studies should be carried out to know the potency and the concentration of different plant origin extracts.


Author(s):  
Marcos Saldanha Correa ◽  
Joseli Schwambach ◽  
Michele Bertoni Mann ◽  
Jeverson Frazzon ◽  
Ana Paula Guedes Frazzon

ABSTRACT: In recent years, compounds with biological properties produced by plants have received attention as an alternative to control microorganisms. Essential oils extracted from green leaves of Eucalyptus sp. have been demonstrated to have antimicrobial activities, but so far there are no reports of antimicrobial activity of essential oils extracted from dried leaves of Eucalyptus staigeriana. So, the objectives of this study were to determine the chemical composition of the essential oils obtained from dried leaves of E. staigeriana (EOdlES) and to evaluate in vitro antimicrobial and antibiofilm activities of EOdlES against gram-positive and gram-negative, resistance and multiresistant Enterococcus faecalis isolated from food and clinical samples. The characterization of EOdlES was performed by gas chromatography-mass spectrometry (GC/MS). For this study, 26 bacterial strains were used, which included 11 reference strains and 15 antibiotic resistant and multiresistant E. faecalis strains. Antimicrobial activities of EOdlES against gram-positive and gram-negative were determined using the disc diffusion method. The minimum inhibitory concentration (MIC) value was evaluated by a microbroth dilution technique. The antibiofilm effects were assessed by microtiter plate method. As a result, 21 compounds were identified, being oxygenated monoterpenes (69.58%) the major chemical family. EOdlES showed only antimicrobial activity against gram-positive strains. E. faecalis resistant and multiresistant strains show the lowest MIC (3.12 to 6.25%), when compared with reference E. faecalis strain. EOdlES has the ability to inhibit the biofilm formation, but little or none ability to inhibit the preformed biofilm. This study demonstrates that EOdlES is a promising alternative to control important foodborne and clinic gram-positive resistant bacteria.


2010 ◽  
Vol 7 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Ramzi A. A. Mothana ◽  
Salah A. A. Abdo ◽  
Sidgi Hasson ◽  
Faisal M. N. Althawab ◽  
Sama A. Z. Alaghbari ◽  
...  

The traditional medicine still plays an important role in the primary health care in Yemen. The current study represents the investigation of 16 selected plants, which were collected from different localities of Yemen. The plants were dried and extracted with two different solvents (methanol and hot water) to yield 34 crude extracts. The obtained extracts were tested for their antimicrobial activity against three Gram-positive bacteria, two Gram-negative bacteria, one yeast species and three multiresistantStaphylococcusstrains using agar diffusion method, for their antioxidant activity using scavenging activity of DPPH radical method and for their cytotoxic activity using the neutral red uptake assay. In addition, a phytochemical screening of the methanolic extracts was done. Antibacterial activity was shown only against Gram-positive bacteria, among them multiresistant bacteria. The highest antimicrobial activity was exhibited by the methanolic extracts ofAcalypha fruticosa,Centaurea pseudosinaica,Dodonaea viscosa,Jatropha variegata,Lippia citriodora,Plectranthus hadiensis,Tragia pungensandVerbascum bottae.Six methanolic extracts especially those ofA. fruticosa,Actiniopteris semiflabellata,D. viscosa,P. hadiensis,T. pungensandV. bottaeshowed high free radical scavenging activity. Moreover, remarkable cytotoxic activity against FL-cells was found for the methanolic extracts ofA. fruticosa,Iris albicans,L. citriodoraandT. pungens. The phytochemical screening demonstrated the presence of different types of compounds like flavonoids, terpenoids and others, which could be responsible for the obtained activities.


Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 178
Author(s):  
Vanessa Silva ◽  
Rupesh Kumar Singh ◽  
Nelson Gomes ◽  
Bruno Gonçalves Soares ◽  
Adriana Silva ◽  
...  

Chitosan, a natural polysaccharide, has been previously proposed as an elicitor in plants to prevent pathogen infections. The present study aimed to analyze the effect of chitosan solution and chitosan nanoparticles treatment applied on the grapevine variety Sousão with respect to the phenolic composition, antioxidant potential and antibacterial activity of its individual grape components. Grapevine plants of selected lines were sprayed with chitosan solution and chitosan nanoparticles, and ethanolic extracts of stems, seeds and skins were prepared from grapevines treated and not treated with chitosan. Total phenolic, anthocyanin and tannin contents were studied, and the identification of the individual phenolic compounds was performed by HPLC-DAD. The antimicrobial susceptibility method was performed using the Kirby-Bauer disc diffusion method against multidrug-resistant bacteria. Overall, there was small increase in the concentration of phenolic compounds, antioxidant and antimicrobial activities in grape components treated with chitosan solution. Seed extracts showed the highest antioxidant and antimicrobial activities. The studied individual components obtained from chitosan-treated grapevines could represent an added value due to the increased antioxidant and antibacterial potentials. The phenolic compounds found in components may be used in food and pharmaceutical industries as natural food preservers and antibiotic adjuvants.


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