scholarly journals Evaluation of Leea rubra Leaf Extract for Oxidative Damage Protection and Antitumor and Antimicrobial Potential

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Nibedita Das ◽  
Sanowar Hossain ◽  
Jaytirmoy Barmon ◽  
Shahnaj Parvin ◽  
Mahadi Hasan ◽  
...  

Background. The leaves of Leea rubra contain an abundance of phenolic constituents and have medicinal uses as antipyretic and diaphoretic agents and are also used in the treatment of stomach ache, rheumatism, arthritis etc. In spite of the traditional uses, data on the scientific evaluation of the plant are not sufficient. So, the present study was designed to evaluate the protective role of the extract against oxidative damage to DNA and human erythrocytes as well as antitumor and antibacterial activities against some resistant bacteria. Methods. The protective activity of the ethyl acetate fraction (EAF) of the extract was investigated by evaluating the inhibition of oxidative damage of pUC19 plasmid DNA as well as hemolysis and lipid peroxidation damage to human erythrocytes induced by 2,2′-azobis-2-amidinopropane (AAPH). Antitumor activity was assessed by evaluating the percentage inhibition of cell growth, morphological changes of Ehrlich’s ascites carcinoma (EAC) cells, and hematological parameters. Antimicrobial activity was determined by the disc diffusion method against different resistant microorganisms. Results. EAF effectively inhibited AAPH-induced oxidative damage to DNA because it can inhibit the transformation of the supercoiled form of plasmid DNA to open circular and further linear form. The oxidative hemolysis caused by AAPH in human erythrocytes was inhibited by EAF extract in a time-dependent manner, and the production of malondialdehyde (MDA) was significantly reduced, which indicates the prevention of lipid peroxidation. In antitumor assay, 76% growth of inhibition of EAC was observed compared with the control mice ( p < 0.05 ) at a dose of 100 mg/kg body weight. Antimicrobial activity was evaluated against two pathogenic resistant microorganisms (Escherichia coli and Pseudomonas aeruginosa), and the highest antimicrobial activity was observed against Pseudomonas spp. Conclusion. EAF may have great importance in preventing oxidative damage to DNA, erythrocytes, and other cellular components as well as can be a good candidate in cancer chemotherapy and treating infectious diseases caused by antibiotic-resistant bacteria.


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



Metabolism ◽  
2009 ◽  
Vol 58 (5) ◽  
pp. 731-734 ◽  
Author(s):  
Robert D. Hoeldtke ◽  
Kimberly D. Bryner ◽  
Linda L. Corum ◽  
Gerald R. Hobbs ◽  
Knox Van Dyke


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.



2019 ◽  
Vol 9 (1) ◽  
pp. 225-228
Author(s):  
Jaswinder Mehta ◽  
Peenu Mahendra Joshi ◽  
Priyanka Kushwaha ◽  
Geeta Parkhe

The aim of present study was to estimate the in vitro antioxidant potential and antimicrobial activity of hydroalcoholic extract of Vernonia cinerea. Antioxidant activity was assessed by using 2, 2- diphenyl-1-picryl-hydrazyl (DPPH) assay using ascorbic acid as standard antioxidant. The extract was found to scavenge effectively the free radicals. The total flavonoid contents were determined by established methods and were found to be 0.547 mg/100mg in quercitin equivalents. Antimicrobial activity was performed against 2 stains of human pathogenic bacteria by well diffusion method. Hydroalcoholic extract of Vernonia cinerea showed good antimicrobial activity against gram positive bacteria. The antioxidant activities may be attributed to the presence of significant amounts of flavonoid compounds. Results indicated that hydroalcoholic extract of Vernonia cinerea possess significant antioxidant effect in dose dependent manner, followed by the hydroalcoholic extract of Vernonia cinerea possessed good antimicrobial activity. Keywords: Antioxidant activity, Radical scavenging activity, Free radicals, Antimicrobial activity.



2019 ◽  
Vol 13 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Margarita Velásquez ◽  
Darío Méndez ◽  
Carlos Moneriz

Background: Pyridoxine has reduction and prevention against the levels of reactive oxygen species in in vitro studies. However, the biochemical mechanism that explains this behavior has not yet been fully clarified. Objective: To evaluate the effect of pyridoxine against oxidative damage on the membrane of human erythrocytes. Methods: Cumene hydroperoxide was used to induce oxidative stress in protein and lipid. Human erythrocytes were incubated with pyridoxine and cumene hydroperoxide, either alone or together for 8 h. Oxidative damage was determined by measuring lipid peroxidation and membrane protein carbonylation. Results: The results indicate that the malondialdehyde concentration decreased with increasing concentration of pyridoxine. The membrane protein content also decreased with increasing concentration of vitamin B6, which was confirmed by the decreased signal intensity in the western blot when compared to control without pyridoxine. Results demonstrate that pyridoxine can significantly decrease lipid peroxidation and protein carbonylation in red cell membrane exposed to high concentrations of oxidant agent. Conclusion: Pyridoxine showed a protective effect against the oxidative stress in human erythrocytes in vitro, inhibiting the carbonylation and the oxidative damage of erythrocyte membrane proteins. To date, such an effect has not yet been reported in terms of protein oxidation.



Nukleonika ◽  
2017 ◽  
Vol 62 (4) ◽  
pp. 245-251 ◽  
Author(s):  
Jesmin Aktar ◽  
Zahid Hasan ◽  
Tahmina Afroz ◽  
Kamruzzaman Pramanik ◽  

Abstract The aim of this study is to exploit a suitable chitosan extraction method from the chitin of indigenous shrimp shells by employing different physicochemical treatments and to improve different bioactive properties of this extracted chitosan (CS) by applying gamma radiation. Chitin was prepared from shrimp shell by pretreatment (deproteination, demineralization and oxidation). Chitosan was extracted from chitin by eight different methods varying different physicochemical parameters (reagent concentration, temperature and time) and assessed with respect to the degree of deacetylation, requirement of time and reagents. The method where chitin was repeatedly treated with 121°C for 30 min with 20 M NaOH, produced the highest degree of deacetylation (DD) value (92%) as measured by potentiometric titration, with the least consumption of time and chemicals, and thus, selected as the best suitable extraction method. For further quality improvement, chitosan with highest DD value was irradiated with different doses (i.e., 5, 10, 15, 20 and 50 kGy) of gamma radiation from cobalt-60 gamma irradiator. As the radiation dose was increased, the molecular weight of the wet irradiated chitosan, as measured by the viscosimetric method, decreased from 1.16 × 105 to 1.786 × 103, 1.518 × 103, 1.134 × 103, 1.046 × 103 and 8.23 × 102 dalton, respectively. The radiation treatment of chitosan samples increased the antimicrobial activity significantly in concentration dependent manner on both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, as determined by the well-diffusion method. Four to five percent wet chitosan treated with a radiation dose range of 5.0–10.0 kGy rendered the highest antimicrobial activity with least energy and time consumption. Solubility, water binding capacity (WBC) and fat binding capacity (FBC) also improved due to irradiation of chitosan.



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.



Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4571
Author(s):  
Abdullah Lone ◽  
Thomas T. Thomsen ◽  
Josefine Eilsø Nielsen ◽  
Peter W. Thulstrup ◽  
Rasmus N. Klitgaard ◽  
...  

The increasing emergence of multi-drug resistant bacteria is a serious threat to public health worldwide. Antimicrobial peptides have attracted attention as potential antibiotics since they are present in all multicellular organisms and act as a first line of defence against invading pathogens. We have previously identified a small all-d antimicrobial octapeptide amide kk(1-nal)fk(1-nal)k(nle)-NH2 (D2D) with promising antimicrobial activity. In this work, we have performed a structure-activity relationship study of D2D based on 36 analogues aimed at discovering which elements are important for antimicrobial activity and toxicity. These modifications include an alanine scan, probing variation of hydrophobicity at lys5 and lys7, manipulation of amphipathicity, N-and C-termini deletions and lys-arg substitutions. We found that the hydrophobic residues in position 3 (1-nal), 4 (phe), 6 (1-nal) and 8 (nle) are important for antimicrobial activity and to a lesser extent cationic lysine residues in position 1, 2, 5 and 7. Our best analogue 5, showed MICs of 4 µg/mL against A. baumannii, E. coli, P. aeruginosa and S. aureus with a hemolytic activity of 47% against red blood cells. Furthermore, compound 5 kills bacteria in a concentration-dependent manner as shown by time-kill kinetics. Circular dichroism (CD) spectra of D2D and compounds 1–8 showed that they likely fold into α-helical secondary structure. Small angle x-ray scattering (SAXS) experiments showed that a random unstructured polymer-like chains model could explain D2D and compounds 1, 3, 4, 6 and 8. Solution structure of compound 5 can be described with a nanotube structure model, compound 7 can be described with a filament-like structure model, while compound 2 can be described with both models. Lipid interaction probed by small angle X-ray scattering (SAXS) showed that a higher amount of compound 5 (~50–60%) inserts into the bilayer compared to D2D (~30–50%). D2D still remains the lead compound, however compound 5 is an interesting antimicrobial peptide for further investigations due to its nanotube structure and minor improvement to antimicrobial activity compared to D2D.



2010 ◽  
Vol 1 (1) ◽  
pp. 17
Author(s):  
Mariellen Guilherme dos Santos ◽  
Dayane Aparecida dos Santos ◽  
Angela Kwiakowski ◽  
Maria Josiane Sereia ◽  
Lívia Bracht

<p>The aim of this paper was to study the in vitro antimicrobial activity of royal jelly obtained from supplemented honey bees against the microorganism Staphylococcus aureus using the disk diffusion method. The royal jelly was obtained from Apis mellifera africanized honey bees fed with complete supplement constituted of palm oil plus linseed oil, palm oil alone, linseed oil alone and with no supplementation. Samples obtained from the different supplementations were applied to paper disks in the concentration range 0 -100%.&nbsp; All the samples of royal jelly were able to inhibit the growth of S. aureus in a dose-dependent manner. There was no difference between the antimicrobial activity of the different samples of royal jelly obtained from supplemented or not supplemented bees.</p><p>&nbsp;</p><p><span>DOI:&nbsp;<a href="http://dx.doi.org/10.14685/rebrapa.v4i1.102">http://dx.doi.org/10.14685/rebrapa.v1i1.3</a></span></p><p>&nbsp;</p>



2020 ◽  
Author(s):  
◽  
David Serunjogi

Abstract 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.



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