scholarly journals In Vitro Antimicrobial effects of Extracts from Leaves of Medicinal Herbs and Native Brazilian Plants

2018 ◽  
Vol 6 (3) ◽  
pp. 243-254
Author(s):  
Bárbara Ponzilacqua ◽  
Sarah Hwa In Lee ◽  
João Luíz Zani ◽  
Roice Eliana Rosim ◽  
Carlos Humberto Corassin ◽  
...  

The objective of this study was to evaluate the antimicrobial effects of crude and lyophilized extracts of leaves from sweet passion fruit (Passiflora alata), araçá (Psidium cattleianum), rosemary (Rosamrinus officinalis) and oregano (Origanum vulgare) on planktonic cells of Staphylococcus aureus and Aspergillus parasiticus. Sweet passion fruit showed no inhibitory effect against the micro-organisms tested. However, crude and lyophilized extracts from Araçá had the highest (P < 0.05) antimicrobial activity against S. aureus, with minimum inhibitory concentrations (MIC) of 0.39 and 0.35 mg/ml, respectively. MIC values against S. aureus for lyophilized extracts from rosemary and crude extracts from oregano were 0.57 and 0.65 mg/ml, respectively. None of the extracts demonstrated effective results against A. parasiticus, although araçá and oregano extracts had the lowest (P < 0.05) MIC values when compared with the other extracts. This preliminary screening study indicated that araçá, rosemary and oregano are interesting alternatives as antimicrobial agents in food substrates, although further studies are needed to develop commercial formulations based on field trials.

2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.


2015 ◽  
Vol 61 (11) ◽  
pp. 827-836 ◽  
Author(s):  
Rossana de Aguiar Cordeiro ◽  
Rosana Serpa ◽  
Francisca Jakelyne de Farias Marques ◽  
Charlline Vládia Silva de Melo ◽  
Antonio José de Jesus Evangelista ◽  
...  

In recent years, the search for drugs to treat systemic and opportunistic mycoses has attracted great interest from the scientific community. This study evaluated the in vitro inhibitory effect of the antituberculosis drugs isoniazid and ethionamide alone and combined with itraconazole and fluconazole against biofilms of Cryptococcus neoformans and Cryptococcus gattii. Antimicrobials were tested at defined concentrations after susceptibility assays with Cryptococcus planktonic cells. In addition, we investigated the synergistic interaction of antituberculosis drugs and azole derivatives against Cryptococcus planktonic cells, as well as the influence of isoniazid and ethionamide on ergosterol content and cell membrane permeability. Isoniazid and ethionamide inhibited both biofilm formation and viability of mature biofilms. Combinations formed by antituberculosis drugs and azoles proved synergic against both planktonic and sessile cells, showing an ability to reduce Cryptococcus biofilms by approximately 50%. Furthermore, isoniazid and ethionamide reduced the content of ergosterol in Cryptococcus spp. planktonic cells and destabilized or permeabilized the fungal cell membrane, leading to leakage of macromolecules. Owing to the paucity of drugs able to inhibit Cryptococcus biofilms, we believe that the results presented here might be of interest in the designing of new antifungal compounds.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1078 ◽  
Author(s):  
Silvia Bittner Fialová ◽  
Martin Kello ◽  
Matúš Čoma ◽  
Lívia Slobodníková ◽  
Eva Drobná ◽  
...  

On its own, rosmarinic acid possesses multiple biological activities such as anti-inflammatory, antimicrobial, cardioprotective and antitumor properties, and these are the consequence of its ROS scavenging and inhibitory effect on inflammation. In this study, two quaternary phosphonium salts of rosmarinic acid were prepared for the purpose of increasing its penetration into biological systems with the aim of improving its antimicrobial, antifungal, antiprotozoal and antitumor activity. The synthetized molecules, the triphenylphosphonium and tricyclohexylphosphonium salts of rosmarinic acid, exhibited significantly stronger inhibitory effects on the growth of HCT116 cells with IC50 values of 7.28 or 8.13 μM in comparison to the initial substance, rosmarinic acid (>300 μM). For the synthesized derivatives, we detected a greater than three-fold increase of activity against Acanthamoeba quina, and a greater than eight-fold increase of activity against A. lugdunensis in comparison to rosmarinic acid. Furthermore, we recorded significantly higher antimicrobial activity of the synthetized derivatives when compared to rosmarinic acid itself. Both synthetized quaternary phosphonium salts of rosmarinic acid appear to be promising antitumor and antimicrobial agents, as well as impressive molecules for further research.


1992 ◽  
Vol 67 (03) ◽  
pp. 325-330 ◽  
Author(s):  
Daniel Bágdy ◽  
Èva Barabás ◽  
Sándor Bajusz ◽  
Erzsébet Széll

SummaryA series of peptide aldehydes synthetized in our institute during the last 15 years were screened to detect their inhibitory effect on blood coagulation. Simple conventional clotting assays, platelet function tests and fibrinolytic methods were used to evaluate the inhibitory potency of the compounds in complex clotting systems as well as their supposed antifibrinolytic effect in vitro. Special attention was paid to the possible interactions with blood cells and plasma proteins, and to the functional stability of the inhibitors in several tissue homogenates. D-Phe-Pro-Arg-H (GYKI-14166, RGH-2958), Boc-D-Phe-Pro-Arg-H (GYKI-14451) and D-MePhe-Pro-Arg-H (GYKI-14766) were found to be the most potent inhibitors. The peptide aldehydes via formation of reversible complexes with thrombin impede the enzyme to react with the coagulation factors, platelet membrane and vessel wall. The compounds inhibit platelet aggregation induced by thrombin specifically without changing the sensitivity of platelets to other inducers. D-Phe-Pro-Arg-H and D-MePhe-Pro-Arg-H showed no antifibrinolytic effect. D-MePhe-Pro-Arg-H and Boc-D-Phe-Pro-Arg-H proved to be stable in dry state for years and in solution at room temperature for several days. The anticoagulant activity of the compounds was declared in NIH antithrombin units.


2012 ◽  
Vol 56 (6) ◽  
pp. 3250-3260 ◽  
Author(s):  
Yabin Zhou ◽  
Ganggang Wang ◽  
Yutang Li ◽  
Yang Liu ◽  
Yu Song ◽  
...  

ABSTRACTThe increase in drug resistance and invasion caused by biofilm formation brings enormous challenges to the management ofCandidainfection. Aspirin's antibiofilm activityin vitrowas discovered recently. The spectrophotometric method and the XTT {2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide} reduction assay used for data generation make it possible to evaluate fungal biofilm growth accurately. The combined use of the most commonly used methods, the fractional inhibitory concentration index (FICI) and a newly developed method, the ΔEmodel, which uses the concentration-effect relationship over the whole concentration range instead of using the MIC index alone, makes the interpretation of results more reliable. As an attractive tool for studying the pharmacodynamics of antimicrobial agents, time-kill curves can provide detailed information about antimicrobial efficacy as a function of both time and concentration. In the present study,in vitrointeractions between aspirin (acetylsalicylic acid [ASA]) and amphotericin B (AMB) against planktonic cells and biofilm cells ofCandida albicansandC. parapsilosiswere evaluated by the checkerboard microdilution method and the time-kill test. Synergistic and indifferent effects were found for the combination of ASA and AMB against planktonic cells, while strong synergy was found against biofilm cells analyzed by FICI. The ΔEmodel gave more consistent results with FICI. The positive interactions in concentration were also confirmed by the time-kill test. Moreover, this approach also revealed the pharmacodynamics changes of ASA and synergistic action on time. Our findings suggest a potential clinical use for combination therapy with ASA and AMB to augment activity against biofilm-associated infections.


2018 ◽  
Author(s):  
◽  
Nkululeko Xaba

Background Due to the rise of antibiotic resistant bacterial infections, alternative methods of treatment need to be explored. Homoeopathic medicine is based on the principle of ‘like cures like’ (O’Reilly, 1996) i.e. the symptoms the substance can cause, it can cure which is the underlying rationale for this study. Colibacillinum is a remedy prepared from an enteropathogenic strain of E. coli, this remedy is already used in clinical practice against chronic cystitis (Leupen, 2010) caused by E. coli, however, an extensive literature search has revealed there to be no empirical investigation into its antibiotic capacity. This study aimed to show whether or not this remedy demonstrates antimicrobial capacity against E. coli in an in vitro setting. Parallell homoeopathic potencies of this remedy and one prepared from a uropathogenic strain of E. coli were tested for antimicrobial effects against enteropathogenic and uropathogenic strains of E. coli in vitro using the disc diffusion method. Aim of the study The aim of this controlled in vitro study is to determine the antimicrobial effectiveness of parallel potencies of the homoeopathic remedy Colibacillinum (manufactured from a uropathogenic strain and enteropathogenic strains respectively) against uropathogenic and enteropathogenic cultures of E. coli in vitro by means of the disc diffusion assay method. Methodology Measurements were by means of the disc diffusion essay. For this experiment thirty Mueller-Hinton plates were prepared and inoculated with each test bacteria in turn. Fifteen plates were inoculated with Uropathogenic strain of E. coli and the remaining 15 plates were inoculated with Uropathogenic strain of E. coli. A sterile 5mm Whatman® filter paper number 4 discs were individually inoculated with test substances 3CH,9CH,30CH and 200CH potencies and the controls, negative (43% ethanol) and positive control (Ciprofloxacin) using a micropipette, before being allowed to dry in the incubator. A Ciprofloxacin antibiotic (positive control) was included in the experiment with sole purpose of accounting for plate-plate variations in the pharmacological sensitivity of the same specie of bacteria. The plates were incubated at 37°C, and the zones of inhibition measured with a pair of Vernier calipers at 24 hours. Data entry was done using the SPSS statistical package. ANOVA was used to compare the differences between the test and control groups, Mauchly’s Test of Sphericity for Uropathogenic prepared strain, Mauchly’s Test of Sphericity for Enteropathogenic prepared strain, Normality test. Results The results obtained from this study showed that the Homoeopathic remedy Colibacillinum prepared from both Uropathogenic and Enteropathogenic strains displayed inhibitory effects against Enteropathogenic and Uropathogenic strains of E. coli, and exhibited statistically significance. The control group (ciprofloxacin) had the highest inhibitory effect (42.3±0.58mm) against Enteropathogenic and Uropathogenic E. coli, while the negative control (43% ethanol) had the lowest inhibitory effect (0.67±1.15mm). Colibacillinun 200CH prepared from a Uropathogenic strain of E-coli (Coli-b_U 200CH) displayed statistically significant antimicrobial effects against uropathogenic E.coli; such antimicrobial effects were significantly greater than 43% ethanol (negative control); the antimicrobial effect was however inferior to Ciprofloxacin (positive control). Colibacillinum 9CH prepared from Enteropathogenic strain of E-coli (Coli-b_E 9CH) also displayed statistically significant antimicrobial effects against enteropathogenic E.coli which were significantly greater than 43% ethanol (negative control) but inferior to Ciprofloxacin. Conclusion This study concluded that Colibacillinum prepared from Uropathogenic and Enteropathogenic strains of E. coli, are effective in inhibiting the in vitro growth of E.coli when evaluated by means of disc diffusion. The study further confirmed that the biological (anti-microbial) activity of an ultra-high homoeopathic dilution (Coli-b_U 200CH) (1:10400) and in the case of Coli-b_U the findings support existing literature which suggests that the anti-microbial properties of homeopathic nosodes increase with potency; all hypotheses for this remedy were thus accepted. This trend was not noted for Coli-b_E in which the potency with the greatest anti-microbial effect was the 9CH, thus Colibacillinum prepared from Enteropathogenic strain (Coli-b_E) did not conform with hypothesies one, two and four that were proposed in chapter one. Despite this the confirmation of significant antimicrobial effects of a substance at this level of deconcentration (1:1018) is noteworthy.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mohd-Al-Faisal Nordin ◽  
Fathilah Abdul Razak ◽  
Wan Harun Himratul-Aznita

Bakuchiol is an active component ofPsoralea glandulosaandPsoralea corylifolia, used in traditional Chinese medicine. The study aimed at investigating the antifungal activity of bakuchiol on planktonic and biofilm forms of orally associatedCandidaspecies. The antifungal susceptibility testing was determined by the broth micro dilution technique. Growth kinetics and cell surface hydrophobicity (CSH) ofCandidawere measured to assess the inhibitory effect of bakuchiol onCandidaplanktonic cells. Biofilm biomass and cellular metabolic activity were quantitatively estimated by the crystal violet (CV) and the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assays. AllCandidastrains have been shown to be susceptible to bakuchiol with the MIC ranges from 12.5 to 100 μg/mL. Significant decrease in specific growth rates and viable counts demonstrates the inhibitory effect of bakuchiol onCandidaplanktonic cells. A brief exposure to bakuchiol also reduced CSH ofCandida(P<0.05), indicating altered surface properties of yeast cells towards hydrophobic interfaces. Biofilm biomass and cell metabolic activity were mostly decreased, except forC. glabrata(P=0.29). The antifungal properties of bakuchiol onCandidaspecies in thisin vitrostudy may give insights into the application in therapeutic strategy againstCandidainfections.


2013 ◽  
Vol 53 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Souad Zaim ◽  
Lakhdar Belabid ◽  
Miloud Bellahcene

Abstract Among 131 rhizobacteria isolates, 29 potentially antagonistic strains were screened in in vitro assays. The five antagonistic Bacillus spp. Rb29, Rb6, Rb12, Rb4, and Rb15 showed the most inhibitory effect against FOC1 (from 25.63 to 71.11%), mycelial growth, and FOC2 (from 28.43 to 60.65%) in vitro. Results also revealed that production of volatile metabolite, components and inhibition of the test pathogen by volatile metabolites varied among different antagonistic rhizobacteria. Isolates Rb29, Rb6, Rb12, Rb4, and Rb15 produced more volatile metabolites which inhibited mycelial FOC growth by 40%. Chickpea Fusarium wilt severity caused by FOC1 was reduced from 60 to 99% in the susceptible cultivar ILC 482 treated with antagonistic Bacillus spp. (Rb29, Rb6, Rb12, Rb4, and Rb15) in pot assays and by 98, 81, 68, 64, 57.20%, respectively, in the field trials. As for their beneficial effects on disease control, the results revealed that Bacillus spp. may improve plant growth and disease control.


2019 ◽  
Vol 8 (1) ◽  
pp. 10-16
Author(s):  
Bahar Ahmadi ◽  
Aazam Aarabi

In this study, rice pedicle extracts (Oriza sativa. L.)  were obtained by high pressure reactor using water, and sodium hydroxide at temperatures of 70, 90, 110 130 °C.  The extracts were evaluated for total phenolic content, antioxidant activity and growth inhibition of Escherichia coli and Candida albicans. Their results were compared to Soxhlet extraction by using ethanol (95%v/v). The results showed that the use of different temperatures had a significant effect on the percentage of phenolic compounds, and the alkali method had a significant effect on the amount of phenolic compounds rather than water extraction (128.72 and 51.79 GA/g, respectively). The highest antimicrobial activity levels were obtained in ethanol extracts that the extracts have inhibitory effect on E. coli. None of extracts had inhibitory effect on Candida albicans. The results provided the evidence that the studied rice (Oriza sativa. L.) pedicle extract might be potential sources of phenolic compound, natural antioxidant and antimicrobial agents.


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