scholarly journals Antimicrobial activity of olive leaf extract on selected foodborne pathogens and its effect on thermal resistance of Listeria monocytogenes in sous vide ground beef

2021 ◽  
pp. 236-242
Author(s):  
Serap COŞANSU AKDEMİR
Keyword(s):  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Thermal Resistance ◽  
Foodborne Pathogens ◽  
Leaf Extract ◽  
Ground Beef ◽  
Olive Leaf ◽  
Olive Leaf Extract ◽  
Sous Vide

scholarly journals Transcriptomics of Listeria monocytogenes Treated With Olive Leaf Extract

2021 ◽  
Vol 12 ◽  
Author(s):  
Yanhong Liu ◽  
Ting Fang ◽  
Yujuan Suo ◽  
Shigang Gao ◽  
Gian Marco Baranzoni ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Mode Of Action ◽  
Leaf Extract ◽  
Host Cells ◽  
Differentially Expressed ◽  
Rna Seq ◽  
Olive Leaf ◽  
Phosphotransferase System ◽  
Olive Leaf Extract ◽  
Flagella Assembly

Listeria monocytogenes is a regulated foodborne pathogen that is known to cause listeriosis, a disease associated with high mortality rates in humans. Olive leaf extract (OLE) has been shown to act as a plant antimicrobial and inhibit the growth of pathogens, such as L. monocytogenes, although its mode of action has not been defined. To help identify the cellular mechanisms important for conveying these beneficial traits, RNA-Seq was used to study the transcriptome of L. monocytogenes upon exposure to a sublethal level of OLE. Results obtained from cells cultured both with and without OLE at two different time points (3.5-h and 24-h) revealed 661 genes that were differentially expressed. Of the differentially expressed genes (DEGs) identified, transcription was altered for 171 genes in response to the 3.5-h OLE treatment while 490 genes were altered in response to the 24-h OLE treatment. These DEGs included but were not limited to genes encoding for signal transduction, ATP-binding cassette (ABC) transporters, and the phosphotransferase system. Interestingly, several virulence-related genes were downregulated including an ABC transporter permease previously shown to negatively regulate biofilm formation, genes involved in flagella assembly and binding/entry into host cells as well as those regulating acid resistance suggesting that OLE may decrease the virulence potential of L. monocytogenes. Furthermore, quantitative reverse-transcription PCR was used to validate the data obtained via RNA-Seq. Our study provides insight into the mode of action of OLE treatment against L. monocytogenes and may aid in identifying synergetic strategies to inhibit L. monocytogenes in food.

scholarly journals Journal of Food Quality Evaluation of Effect of Extraction Solvent on Selected Properties of Olive Leaf Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Won-Young Cho ◽  
Da-Hee Kim ◽  
Ha-Jung Lee ◽  
Su-Jung Yeon ◽  
Chi-Ho Lee
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Leaf Extract ◽  
Radical Scavenging ◽  
Total Phenolic ◽  
Distilled Water ◽  
Olive Leaf ◽  
Leaf Extracts ◽  
Antioxidant Power ◽  
Olive Leaf Extract

The quest for natural preservatives and functional foods with health benefits has seen an increasing demand for natural products having therapeutic value. Herein, we investigated the influence of ethanol, methanol, acetone (50%, 70%, and 90% v/v), and distilled water on selected properties of olive leaf extract and determined the yield, total phenolic content (TPC), antioxidant activity, and antimicrobial activity. Extracts were analyzed for their oleuropein, hydroxytyrosol, and tyrosol contents by high-performance liquid chromatography (HPLC). The highest extraction yield of 20.41% was obtained when using 90 vol% methanol, while the highest total polyphenol contents of 232 and 231 mggallic-acid-equivalent/100 g were obtained for 90 vol% methanol and 90 vol% ethanol, respectively. Antioxidant activity was determined using the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging assay, by determining the ferric reducing antioxidant power (FRAP), and using the Fe2+-chelating activity assay, which provided the highest values when 90 vol% methanol was used (33.84%, 0.75, and 12.91%, respectively). HPLC analysis showed that the highest oleuropein contents corresponded to the extracts obtained using 90 and 70 vol% methanol (26.10 ± 0.20 and 24.92 ± 1.22 g/L, respectively), and the highest antimicrobial activity was observed for 90 vol% methanol and distilled water. Olive leaf extracts using 90 vol% methanol had high levels of polyphenols and were highly antioxidant and antimicrobial. The results of this study facilitate the commercial applications of natural extracts with antioxidant and antibacterial activities and are expected to establish a foundation for further optimization studies.

Antimicrobial activity of commercial Olea europaea (olive) leaf extract

2009 ◽  
Vol 33 (5) ◽  
pp. 461-463 ◽  
Author(s):  
Aurelia N. Sudjana ◽  
Carla D’Orazio ◽  
Vanessa Ryan ◽  
Nooshin Rasool ◽  
Justin Ng ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Olea Europaea ◽  
Leaf Extract ◽  
Olive Leaf ◽  
Olive Leaf Extract ◽  
Olea Europaéa

scholarly journals Combined Antimicrobial Effect of Bio-Waste Olive Leaf Extract and Remote Cold Atmospheric Plasma Effluent

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1890
Author(s):  
Jose Gustavo De la Ossa ◽  
Hani El Kadri ◽  
Jorge Gutierrez-Merino ◽  
Thomas Wantock ◽  
Thomas Harle ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Leaf Extract ◽  
Preliminary Investigation ◽  
Atmospheric Plasma ◽  
Aureus Strain ◽  
Bacterial Inactivation ◽  
Olive Leaf ◽  
Cold Atmospheric Plasma ◽  
E Coli ◽  
Olive Leaf Extract

A novel strategy involving Olive Leaf Extract (OLE) and Cold Atmospheric Plasma (CAP) was developed as a green antimicrobial treatment. Specifically, we reported a preliminary investigation on the combined use of OLE + CAP against three pathogens, chosen to represent medical and food industries (i.e., E. coli, S. aureus and L. innocua). The results indicated that a concentration of 100 mg/mL (total polyphenols) in OLE can exert an antimicrobial activity, but still insufficient for a total bacterial inactivation. By using plain OLE, we significantly reduced the growth of Gram positive S. aureus and L. innocua, but not Gram-negative E. coli. Instead, we demonstrated a remarkable decontamination effect of OLE + CAP in E. coli, S. aureus and L. innocua samples after 6 h. This effect was optimally maintained up to 24 h in S. aureus strain. E. coli and L. innocua grew again in 24 h. In the latter strain, OLE alone was most effective to significantly reduce bacterial growth. By further adjusting the parameters of OLE + CAP technology, e.g., OLE amount and CAP exposure, it could be possible to prolong the initial powerful decontamination over a longer time. Since OLE derives from a bio-waste and CAP is a non-thermal technology based on ionized air, we propose OLE + CAP as a potential green platform for bacterial decontamination. As a combination, OLE and CAP can lead to better antimicrobial activity than individually and may replace or complement conventional thermal procedures in food and biomedical industries.

scholarly journals Olive leaf extract prevents obesity, cognitive decline, and depression and improves exercise capacity in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshio Mikami ◽  
Jimmy Kim ◽  
Jonghyuk Park ◽  
Hyowon Lee ◽  
Pongson Yaicharoen ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Exercise Capacity ◽  
Endurance Exercise ◽  
Leaf Extract ◽  
Metabolic Diseases ◽  
Olive Leaf ◽  
Olive Leaf Extract ◽  
Hypoxic Conditions ◽  
G Protein Coupled ◽  
Antioxidant Effects

AbstractObesity is a risk factor for development of metabolic diseases and cognitive decline; therefore, obesity prevention is of paramount importance. Neuronal mitochondrial dysfunction induced by oxidative stress is an important mechanism underlying cognitive decline. Olive leaf extract contains large amounts of oleanolic acid, a transmembrane G protein-coupled receptor 5 (TGR5) agonist, and oleuropein, an antioxidant. Activation of TGR5 results in enhanced mitochondrial biogenesis, which suggests that olive leaf extract may help prevent cognitive decline through its mitochondrial and antioxidant effects. Therefore, we investigated olive leaf extract’s effects on obesity, cognitive decline, depression, and endurance exercise capacity in a mouse model. In physically inactive mice fed a high-fat diet, olive leaf extract administration suppressed increases in fat mass and body weight and prevented cognitive declines, specifically decreased working memory and depressive behaviors. Additionally, olive leaf extract increased endurance exercise capacity under atmospheric and hypoxic conditions. Our study suggests that these promising effects may be related to oleanolic acid’s improvement of mitochondrial function and oleuropein’s increase of antioxidant capacity.

scholarly journals Olive leaf extract impairs mitochondria by pro-oxidant activity in MDA-MB-231 and OVCAR-3 cancer cells

2021 ◽  
Vol 134 ◽  
pp. 111139
Author(s):  
Reyes Benot-Dominguez ◽  
Maria Grazia Tupone ◽  
Vanessa Castelli ◽  
Michele d’Angelo ◽  
Elisabetta Benedetti ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Leaf Extract ◽  
Olive Leaf ◽  
Olive Leaf Extract
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