scholarly journals ANTIMICROBIAL ACTIVITY AND CHEMICAL CHARACTERIZATION OF LAUREL ESSENTIAL OIL

Author(s):  
Juliana Olívia Nicolao ◽  
Franciana Aparecida Volpato Bellaver ◽  
Volmir Kist ◽  
Daniel Radin ◽  
Marcelo Mendes De Haro ◽  
...  

The factors that arouse interest in the study of essential oils as biocidal agents are numerous, such as the fact that they have antibacterial, antifungal, insecticidal, antioxidant, anti-inflammatory and larvicidal properties. The objective of this work was to evaluate the antimicrobial activity, in vitro, of the laurel (Laurus nobilis L) essential oil on the growth of pathogenic bacteria Salmonella enterica serovar Typhimurium ATCC 14028 and Staphylococcus aureus ATCC 25923, at different exposure times, as well as to perform the chemical characterization. Twenty compounds were identified and quantified, representing 96.57% of the total composition. The class of oxygenated monoterpenes represented the majority class of the essential oil, with 1,8-cineol (33.8%) as the substance found in greater quantity, followed by linalool (17.79%). The third constituent in greater quantity was sabinene (12.23%), belonging to the group of monoterpene hydrocarbons. Terpinyl acetate (9.41%) was also considered to be quantitatively representative. Laurel essential oil showed bacteriostatic activity against S. Typhimurium ATCC 14028 and S. aureus ATCC 25923.

2020 ◽  
Vol 42 (5) ◽  
pp. 1799-1808
Author(s):  
Irene Laura Cibanal ◽  
◽  
Leticia Andrea Fernández ◽  
Giovanni Galietta Positano ◽  
Lucía Bóffano Chebataroff ◽  
...  

2020 ◽  
Author(s):  
Md. Akil Hossain ◽  
Hae-Chul Park ◽  
Kwang-jick Lee ◽  
Sung-Won Park ◽  
Seung-Chun Park ◽  
...  

Abstract Background: The antibiotics generally used in farm animals are rapidly losing their effectiveness all over the world as bacteria develop antibiotic resistance. Like some other pathogenic bacteria multidrug-resistant strains of Salmonella enterica serovar Typhimurium (S. Typhimurium) are also frequently found in animals and humans which poses a major public health concern. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. Thus, this study aimed to increase the efficacy of existing antibiotics against S. Typhimurium by combining them with opportunistic phenolic compounds gallic acid (GA), epicatechin, epicatechin gallate, epigallocatechin and hamamelitannin. Fractional inhibitory concentration indexes (FICI) of phenolic compound-antibiotic combinations against S. Typhimurium were determined. Based on the FICI and clinical importance, 1 combination (GA and ceftiofur) was selected for evaluating its effects on the virulence factors of this bacterium. Viability of Rattus norvegicus (IEC-6) cell in presence of this antibacterial combination was evaluated.Results: Minimum inhibitory concentrations (MICs) of GA, epigallocatechin and hamamelitannin found against different strains of S. Typhimurium were 256, (512–1024), and (512–1024) μg/mL, respectively. Synergistic antibacterial effect was obtained from the combination of erythromycin-epicatechin gallate (FICI: 0.50) against S. Typhimurium. Moreover, additive effects (FICI: 0.502–0.750) were obtained from 16 combinations against this bacterium. The time-kill assay and ultrastructural morphology showed that GA-ceftiofur combination more efficiently inhibited the growth of S. Typhimurium compared to individual antimicrobials. Biofilm viability, and swimming and swarming motilities of S. Typhimurium in presence of GA-ceftiofur combination were more competently inhibited than individual antimicrobials. Viabilities of IEC-6 cells were more significantly enhanced by GA-ceftiofur combinations than these antibacterials alone.Conclusions: This study suggests that GA-ceftiofur combination can be potential medication to treat S. Typhimurium-associated diarrhea and prevent S. Typhimurium-associated blood-stream infections (e.g.: fever) in farm animals, and ultimately its transmission from animal to human. Further in vivo study to confirm these effects and safety profiles in farm animal should be undertaken for establishing these combinations as medications.


Author(s):  
Zakaria Barbeche ◽  
Hocine Laouer ◽  
Ramazan Erenler ◽  
Mohamed Hajji ◽  
Guido Flamini ◽  
...  

Background: Traditionally, The Algerian medicinal plant Elaeosilenum thapsioides have been used for many diseases. Objective: The present research work is aimed to explore the chemical and biological characterization of essential oil of, Elaeoselinum thapsioides (Desf.) Maire. Methods : The essential oils were obtained by hydrodistillation of different Elaeosilenum thapsioides (Apiaceae) aerial parts samples collected from two different regions (Mahouane and Megres) Setif, Eastern Algeria. The chemical characterization of the obtained essential oils was investigated in the present work for the first time by GC and GC-MS. Besides, they were evaluated for their in-vitro acetylcholinesterase (AChE) inhibitory activity whose enzyme hyperactivity is involved in Alzheimer’s disease. Using Ellman’s spectrophotometric method, additionally, their in-vitro antimicrobial activity was assessed by the disc diffusion method. Both activities were performed at various oil concentrations. Results: The GC/MS analysis of the aerial parts (leaves, stems, flowers, and seeds) essential oils of E. thapsioides revealed the presence of dominant compounds and others in small quantities, identifying 47 chemical molecules. Monoterpene hydrocarbons were the main components, ranging from 72.78 % to 99.13 %. Oxygenated monoterpenes and oxygenated sesquiterpenes ranged between (1.37 % -17.25 %) and (0.12 % -3.53 %) in leaves and stem essential oils. Sesquiterpene hydrocarbons were present in small to large quantities in the essential oils of both populations, with contents ranging from 0.69 % to 13.44 %. For the Isothiocyanates, their presence was recorded in leaves and stem essential oils from Mahouane and Merges with 9.73 % and 3.72 %, consecutively. Indeed, the essential oil of the Mahouane stem showed the highest AChE inhibitory activity among all the tested essential oils. Whereas the highest antibacterial activity was shown by the essential oil obtained from Megres leaves against Bacillus cereus ATCC 11778. Conclusion: The oils exhibited a moderate inhibitory activity in both activities.


Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 66
Author(s):  
Osama Elhag ◽  
Yuanpu Zhang ◽  
Xiaopeng Xiao ◽  
Minmin Cai ◽  
Longyu Zheng ◽  
...  

Black soldier fly (BSF) larvae are often exposed to organic waste which harbors abundant zoonotic pathogens. We investigated the ability of BSF larvae to inhibit the zoonotic pathogens naturally found in pig manure. The zoonotic pathogens populations were detected by using selective medium during the conversion. Results showed that the viability of the zoonotic pathogens in pig manure was significantly affected. After eight days of conversion, the Coliform populations were undetected, and Staphylococcus aureus and Salmonella spp. decreased significantly on the eighth day. Antimicrobial assays of the purified recombinant defensin-like peptide 4 (DLP4) showed that this peptide exhibits inhibitory activity against S. aureus, Salmonella enterica serovar typhimurium, and Escherichia coli in vitro. Bacteria BSF-CL and BSF-F were isolated from the larvae gut, and both inhibited the growth of S. aureus and E. coli, but Salmonella spp. was sensitive to the BSF-CL strain (but not to the BSF-F strain). The results from our experiments indicate that BSF larvae are capable of functionally inhibiting potential zoonotic pathogens in pig manure through a variety of mechanisms including antimicrobial peptides expression and the gut associate microorganisms. This study provides a theoretical basis for further study on the combined mechanism of BSF larvae immunity and its gut microbes against the zoonotic pathogens in pig manure.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Kristina Ložienė ◽  
Juozas Labokas ◽  
Vaida Vaičiulytė ◽  
Jurgita Švedienė ◽  
Vita Raudonienė ◽  
...  

The study aimed to establish the chemical composition of fruit essential oils of M. gale and test their activities against the selected pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii), yeasts (Candida albicans, C. parapsilosis), fungi (Aspergillus fumigatus, A. flavus) and dermatophytes (Trichophyton rubrum, T. mentagrophytes). Fruit samples from natural (Western Lithuania) and anthropogenic (Eastern Lithuania) M. gale populations were studied separately. Essential oils were isolated from dried fruits by hydrodistillation and analysed by GC/FID and GC/MS methods; enantiomeric composition of α-pinene was established by chiral-phase capillary GC. Minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) of essential oils were determined using the broth microdilution method. Plants from the natural population with a humid marine climate accumulated significantly higher amounts of fruit essential oils (3.34±0.05%) than those from the anthropogenic population with a more continental climate (2.71±0.22%). In total, 39 volatiles including α-pinene (23.52–27.17%), 1,8-cineole (17.19–18.84%) and α-phellandrene (9.47–10.03%) as main compounds were identified. Chiral analysis demonstrated that (1S)-(–)-α-pinene prevailed over (1R)-(+)-α-pinene and amounted to 94.09–95.28% of all fraction of this monoterpene. The antimicrobial study in vitro indicated that C. parapsilosis, dermatophytes and Aspergillus fungi were more susceptible to fruit essential oils of M. gale, whereas E. coli and C. albicans were weakly inhibited even at the highest essential oil concentration. The strongest growth-inhibitory and bactericidal effect of sweet gale essential oil was established on S. aureus. This could be attributed to the major essential oil compounds with known antimicrobial activity, such as α-pinene, 1,8-cineole and a-phellandrene. Keywords: Myrica gale; essential oil; chemical compounds; terpenes; enantiomers; antimicrobial.


2003 ◽  
Vol 185 (1) ◽  
pp. 332-339 ◽  
Author(s):  
Michael Dougherty ◽  
Diana M. Downs

ABSTRACT In bacteria the biosynthetic pathways for purine mononucleotides and the hydroxymethyl pyrimidine moiety of thiamine share five reactions that result in the formation of aminoimidazole ribotide, the last metabolite common to both pathways. Here we describe the characterization of a Salmonella enterica mutant strain that has gained the ability to efficiently use exogenous aminoimidazole riboside (AIRs) as a source of thiamine. The lesion responsible for this phenotype is a null mutation in a transcriptional regulator of the GntR family (encoded by stm4068). Lack of this protein derepressed transcription of an associated operon (stm4065-4067) that encoded a predicted kinase. The stm4066 gene product was purified and shown to have AIRs kinase activity in vitro. This activity was consistent with the model presented to explain the phenotype caused by the original mutation. This mutation provides a genetic means to isolate the synthesis of the hydroxymethyl pyrimidine moiety of thiamine from the pathway for purine mononucleotide biosynthesis and thus facilitate in vivo analyses.


2020 ◽  
Vol 9 (10) ◽  
pp. e8129108447
Author(s):  
Yuri Nascimento Fróes ◽  
Ana Patrícia Matos Pereira ◽  
Paulo Victor Serra Rosa ◽  
Laiane Araujo da Silva Souto ◽  
Mariana Oliveira Arruda ◽  
...  

The application of natural substances with bactericidal action is the target of research aimed at a more sustainable production, implying in various sources of substances for new therapeutic formulations. This study presents the chemical characterization, toxicity and antimicrobial activity of essential oil (EO) of Bixa orellana Labill leaves. EO was extracted by hydrodistillation at 100°C for 3h. Physicochemical parameters were determined and chemical characterization used Gas chromatography coupled with Mass Spectrometry (GC/MS). The toxicity assay was performed through the bioassay with Artemia salina Leach. The methods of Disc Diffusion and Dilution in Broth in front of the bacteria Escherichia coli and Staphylococcus aureus were used to evaluate the antimicrobial activity. LC50 in the toxicity assay was verified in 355 mg L-1 and was classified as nontoxic. The OE presented antimicrobial activity against the microorganisms tested and totaled 320 mg EAT g-1 of total phenolics. The results obtained highlight the importance of pointing out this product as a therapeutic alternative, encouraging its application potential.


2020 ◽  
Vol 16 (15) ◽  
Author(s):  
Jhunior Abrahan Marcía Fuentes ◽  
Ismael Montero Fernandez ◽  
Ricardo Santos Aleman ◽  
Selvin Antonio Saravia Maldonado ◽  
Leonardo Flores Roger ◽  
...  

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