scholarly journals Leptospermum petersonii as a Potential Natural Food Preservative

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5487
Author(s):  
Wasiu Olalekan Afolabi ◽  
Ahmed Hussein ◽  
Francis Oluwole Shode ◽  
Marilize Le Roes-Hill ◽  
Fanie Rautenbach

Leptospermum petersonii (family Myrtaceae) is often cultivated for ornamental purposes but also serves as a rich source of bioactive essential oils. While several studies focused on the activities of the essential oils, this study analysed the potential of spent L. petersonii leaves as a natural food preservative. Method: We investigated the in vitro antioxidant and antimicrobial activities of crude L. petersonii extracts against activities of the purified isolated flavonoid, 6-methyltectochrysin, which was characterized using spectroscopic methods. The antioxidant assays followed ORAC, FRAP and TEAC tests. The antimicrobial activities of the extract and purified flavonoid were analysed against six multi-drug resistant microbial strains in broth dilution assays. Result: The results revealed that both the crude extracts and isolated 6-methyltectochrysin exhibited positive radical ion scavenging antioxidant potential, however the crude extract was about 6-fold more potent antioxidant than the purified 6-methyltectochrysin. The crude extract also showed strong antimicrobial activities against Bacillus cereus, and even more potent antimicrobial agent than the reference ampicillin antibiotic against Klebsiella pneumoniae subsp. pneumoniae. A higher resistance was observed for the tested Gram-negative strains than for the Gram-positive ones. 6-methyltectochrysin was generally inactive in the antimicrobial assays. Conclusion: The crude methanolic extract showed significant bioactivity which validates the medicinal relevance of the plant. The observed biological activities, especially against a notorious strain of B. cereus, suggest that L. petersonii could be a promising natural source of food preservatives.

2018 ◽  
Vol 28 (4) ◽  
pp. 10-18
Author(s):  
Zahaed Evangelista-Martínez ◽  
Nohemí Reyes-Vázquez ◽  
Ingrid Rodríguez-Buenfil

Essential oils (EO) are promising natural antimicrobial additives to control microbial pathogens. This study aims to investigate the antimicrobial activities of plant essential oils and to study the antimicrobial effect of oregano oil (OrO) in combination with food preservatives. The antimicrobial screening showed that Escherichia coli and Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella ser. Typhimurium) appeared to be less susceptible to EO, whereas Staphylococcus aureus and Candida albicans were more affected. The Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) for laurel, cumin, oregano and rosemary oils showed values ranging from 0.078% to 1.25% (v/v). Also, synergic and viability effects of OrO combined with acetic acid (AcA) showed an additive effect against E. coli and C. albicans, while combination OrO + ascorbic acid (Asc) exhibited the same effect over Salmonella ser. Typhimurium and C. albicans. Therefore, oregano oil in combination with preservatives could be used to control the growth of pathogenic microorganisms for food preservation.


2020 ◽  
Vol 49 (4) ◽  
pp. 957-965
Author(s):  
Omer Elkiran ◽  
Cumhur Avsar

The chemical composition, antimicrobial and antioxidant properties of the essential oils from the leaves of endemic Thymus leucostomus naturally grown in Turkey were investigated and chemical differences were discussed by means of chemotaxonomy. Twenty-six components were identified representing 98.8% of the oils. The main compounds in the essential oil of T. leucostomus were: o-cymene (30.6%), carvacrol (9.6%), thymol methyl ether (7.2%), limonene (6.8%). Essential oil was screened for their antimicrobial activities against 7 bacteria and 2 yeast species by using disc-diffusion and MIC procedure. The essential oil showed higher effectiveness against all the tested bacteria and yeast. The extract was observed to be much more effective in Gram-positive bacteria (especially, S. aureus ATCC 6538). In vitro antioxidant activity based on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical was evaluated for the essential oil, and it was found that the essential oil had good antioxidant activity in the range of the IC50= 5.42 ±0.8 μg/ml.


2021 ◽  
Vol 11 (13) ◽  
pp. 5778
Author(s):  
Wei Liao ◽  
Waisudin Badri ◽  
Emilie Dumas ◽  
Sami Ghnimi ◽  
Abdelhamid Elaissari ◽  
...  

The global demand for safe and healthy food with minimal synthetic preservatives is continuously increasing. Natural food antimicrobials and especially essential oils (EOs) possess strong antimicrobial activities that could play a remarkable role as a novel source of food preservatives. Despite the excellent efficacy of EOs, they have not been widely used in the food industry due to some major intrinsic barriers, such as low water solubility, bioavailability, volatility, and stability in food systems. Recent advances in nanotechnology have the potential to address these existing barriers in order to use EOs as preservatives in food systems at low doses. Thus, in this review, we explored the latest advances of using natural actives as antimicrobial agents and the different strategies for nanoencapsulation used for this purpose. The state of the art concerning the antibacterial properties of EOs will be summarized, and the main latest applications of nanoencapsulated antimicrobial agents in food systems will be presented. This review should help researchers to better choose the most suitable encapsulation techniques and materials.


2020 ◽  
Vol 16 ◽  
Author(s):  
Adinath D. Badar ◽  
Shubham M. Sulakhe ◽  
Mahesh B. Muluk ◽  
Naziya N. M. A. Rehman ◽  
Prashant P. Dixit ◽  
...  

Background: Thiosemicarbazone, 1,2,3-triazole and their derivatives received great pharmaceutical importance due to their prominent biological activities. In the present study, the molecular hybrid thiosemicarbazone-1,2,3-triazoles derivatives were synthesized and screened for their antimicrobial activities. Methods: A series of thiosemicarbazone clubbed with 1,2,3-triazole derivatives were synthesized via click chemistry approach in good yields. The structures of synthesized compounds were assigned by their spectral data. The in vitro antimicrobial activity was performed by the agar well diffusion method. A molecular docking study was performed to identify the possible mode of action of synthesized derivatives. Results: The compounds 5d, 5h, 5i and 5k have exhibited excellent antimicrobial activities against both antibacterial and antifungal pathogens. The active thiosemicarbazone-1,2,3-triazole derivatives have shown excellent binding affinity towards DNA gyrase. Conclusion: The molecular hybrid thiosemicarbazone-1,2,3-triazole derivatives were synthesized. The newly synthesized compounds were evaluated for their antimicrobial activities. Few of the thiosemicarbazone-1,2,3-triazoles derivatives have exhibited good antimicrobial activities. They have been shown excellent binding affinity towards DNA gyrase.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 114
Author(s):  
Armina Morkeliūnė ◽  
Neringa Rasiukevičiūtė ◽  
Lina Šernaitė ◽  
Alma Valiuškaitė

The Colletotrichum spp. is a significant strawberry pathogen causing yield losses of up to 50%. The most common method to control plant diseases is through the use of chemical fungicides. The findings of plants antimicrobial activities, low toxicity, and biodegradability of essential oils (EO), make them suitable for biological protection against fungal pathogens. The aim is to evaluate the inhibition of Colletotrichum acutatum by thyme, sage, and peppermint EO in vitro on detached strawberry leaves and determine EO chemical composition. Our results revealed that the dominant compound of thyme was thymol 41.35%, peppermint: menthone 44.56%, sage: α,β-thujone 34.45%, and camphor: 20.46%. Thyme EO inhibited C. acutatum completely above 200 μL L−1 concentration in vitro. Peppermint and sage EO reduced mycelial growth of C. acutatum. In addition, in vitro, results are promising for biological control. The detached strawberry leaves experiments showed that disease reduction 4 days after inoculation was 15.8% at 1000 μL L−1 of peppermint EO and 5.3% at 800 μL L−1 of thyme compared with control. Our findings could potentially help to manage C. acutatum; however, the detached strawberry leaves assay showed that EO efficacy was relatively low on tested concentrations and should be increased.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3170
Author(s):  
Wafaa M. Elkady ◽  
Mariam H. Gonaid ◽  
Miriam F. Yousif ◽  
Mahmoud El-Sayed ◽  
Hind A. N. Omar

Active components from natural sources are the current focus in most pharmacological research to provide new therapeutic agents for clinical use. Essential oils from the Pinus species have been traditionally used in medicine. This study aimed to investigate the chemical profile of two Pinus species, Pinus halepensis L. and Pinus pinea Mill, from different altitudes in Libya and study the effect of environmental conditions on the biological activities of essential oils. A clevenger apparatus was used to prepare the essential oils by hydrodistillation. Analyses were done using GC/MS. Anthelmintic and antimicrobial activities were tested against the earthworm Allolobophora caliginosa, gram-positive bacteria, gram-negative bacteria, and fungi. Different chemical profiles were observed among all tested essential oils, and terpenes were the most dominant class. All studied essential oils from the Pinus species exhibited a remarkable anthelmintic activity compared to the standard piperazine citrate drug. Pinus halepensis from both altitudes showed broad-spectrum antimicrobial activity against all tested microorganisms, while Pinus pinea was effective against only Escherichia coli. From these findings, one can conclude that there are variations between studied species. The essential oil compositions are affected by environmental factors, which consequently affect the anthelmintic and antimicrobial activity.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Kamel Msaada ◽  
Nidhal Salem ◽  
Olfa Bachrouch ◽  
Slim Bousselmi ◽  
Sonia Tammar ◽  
...  

The aim of this study was to determine the chemical variability of wormwood extracts as affected by the growing region. Antioxidant and antimicrobial activities were also investigated. The essential oil composition variability ofA. absinthiumL. aerial parts collected from four different Tunisian regions was assessed by gas chromatography (GC/FID) and by gas chromatography mass spectrometry (GC/MS). In addition, total polyphenols, flavonoids, and condensed tannins as well as antioxidant, antibacterial, and antifungal activities of methanolic extract and essential oils were undertaken. Chromatographic analysis of wormwood essential oils showed the predominance of monoterpene hydrocarbons represented mainly by chamazulene. RP-HPLC analysis of wormwood methanolic extract revealed the predominance of phenolic acids. Antiradical activity was region-dependant and the methanolic extract of Bou Salem region has the strongest activity (CI50=9.38±0.82 µg/mL). Concerning the reducing power, the methanolic extract of Bou Salem, Jérissa, and Boukornine regions was more active than the positive control. Obtained results of antimicrobial activities showed that wormwood essential oil is endowed with important antibacterial activity which was strongly related to the organoleptic quality of oil which appeared strongly region-dependant.A. absinthiumL. EOs investigated are quite interesting from a pharmaceutical standpoint because of their biological activities.


2020 ◽  
Vol 9 (10) ◽  
pp. e5049108788
Author(s):  
Luciane Neris Cazella ◽  
Herika Line de Marko de Oliveira ◽  
Wanessa de Campos Bortolucci ◽  
Isabelle Luiz Rahal ◽  
Irinéia Paulina Baretta ◽  
...  

Baccharis dracunculifolia, native to Brazil and the main source of “green propolis”, has been reported with several biological activities, and may be a source of bovine tick control substituting synthetic acaricides. Objective: to evaluate the in vitro and ex situ acaricidal activity of B. dracunculifolia leaf and flower essential oils against Rhipicephalus microplus. Methodology: the essential oils were extracted by hydrodistillation and analyzed by a gas chromatography coupled to mass spectrometry; the acaricidal activity of the essential oil was evaluated in vitro against adult females and against the egg hatchability; moreover, the acaricidal activity against tick larvae was evaluated in vitro and ex situ. Results: the major class of the essential oils was oxygenated sesquiterpene (55.1% leaves 50.4% flowers) and the main compounds were (21.5% leaves; 20.6% flowers) and spathulenol (21.8% leaves; 20.3% flowers). The essential oil at 500 mg/mL was effective to control egg hatchability with a reduction of egg laying capacity and decrease of number of adult ticks and larvae. The larvicidal activity of the essential oil had LC99.9 from 35 to 37 mg/mL by probit analysis, and the essential oil from 11 to 14 mg/mL presented 85 to 95% of treatment efficiency in the ex situ test. Conclusion: B. dracunculifolia leaf and flower essential oils are stable and have application potential to control bovine ticks.


Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2626
Author(s):  
Wael Sobhy Darwish ◽  
Abada El Sayed Khadr ◽  
Maher Abd El Naby Kamel ◽  
Mabrouk A. Abd Eldaim ◽  
Ibrahim El Tantawy El Sayed ◽  
...  

Ceratonia siliqua (Carob) is an evergreen Mediterranean tree, and carob pods are potentially nutritive and have medicinal value. The present study was carried out to estimate the possible biological activities of phytochemical-characterized carob pod aqueous extract (CPAE). The phytochemical contents of CPAE were determined by using colorimetric methods and HPLC. In addition, the free radical scavenging properties and anti-diabetic, anti-hemolytic, and antimicrobial activities were estimated by using standardized in vitro protocols. The phytochemical analysis revealed that CPAE was rich in polyphenols, flavonoids, and alkaloids, where it contained a significant amount of gallic acid, catechin, and protocatechuic acid. Furthermore, CPAE exhibited strong antioxidant activity where it prevented the formation of 2, 2-Diphenyl-1-picryl hydrazyl, hydroxyl, and nitric oxide free radicals. Additionally, it had a potent inhibitory effect against digestive enzymes (amylase, maltase, sucrase, and lactase). Moreover, CPAE exhibited anti-Staph aureus, anti-Escherichia coli, anti-Candida albicans, and anti-herpes simplex type I virus (HSV-I). Finally, CPAE protected the erythrocyte membrane from hypotonic solution-induced hemolysis. Altogether, CPAE could be regarded as an interesting source of biologically active antioxidant, anti-diabetic, and antimicrobial preparation for a potential application in pharmaceutical and food supplement fields.


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