scholarly journals Chemical Composition, Anti-Quorum Sensing, Enzyme Inhibitory, and Antioxidant Properties of Phenolic Extracts of Clinopodium nepeta L. Kuntze

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1955
Author(s):  
Hatem Beddiar ◽  
Sameh Boudiba ◽  
Merzoug Benahmed ◽  
Alfred Ngenge Tamfu ◽  
Özgür Ceylan ◽  
...  

Phenolic extracts of Clinopodium nepeta were prepared and their preliminary phenolic profiles determined using HPLC-DAD with 26 phenolic standards. Apigenin (21.75 ± 0.41 µg/g), myricetin (72.58 ± 0.57 µg/g), and rosmarinic acid (88.51 ± 0.55 µg/g) were the most abundant compounds in DCM (dichloromethane), AcOEt (ethyl acetate), and BuOH (butanol) extracts, respectively. The DCM and AcOEt extracts inhibited quorum-sensing mediated violacein production by C. violaceum CV12472. Anti-quorum-sensing zones on C. violaceum CV026 at MIC (minimal inhibitory concentration) were 10.3 ± 0.8 mm for DCM extract and 12.0 ± 0.5 mm for AcOEt extract. Extracts showed concentration-dependent inhibition of swarming motility on flagellated P. aeruginosa PA01 and at the highest test concentration of 100 μg/mL, AcOEt (35.42 ± 1.00%) extract displayed the best activity. FRAP assay indicated that the BuOH extract (A0.50 = 17.42 ± 0.25 µg/mL) was more active than standard α-tocopherol (A0.50 = 34.93 ± 2.38 µg/mL). BuOH extract was more active than other extracts except in the ABTS●+, where the DCM extract was most active. This antioxidant activity could be attributed to the phenolic compounds detected. C. nepeta extracts showed moderate inhibition on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, and α-amylase. The results indicate that C. nepeta is a potent source of natural antioxidants that could be used in managing microbial resistance and Alzheimer′s disease.

Author(s):  
Abu F. Meka ◽  
Yadessa M. Ayana ◽  
Teshome G. Biru

The main objective of this study was to isolate bioactive compounds from Ekebergia capensis for antimicrobial, anti-biofilm and anti-quorum sensing activity. The bark of E. capensis was extracted using hexane, ethyl acetate and methanol for 72 hours on maceration at room temperature. Antibacterial activity was evaluated against Staphylococcus aureus and antifungal activity against Candida albicans at 5 and 10 mg/mL concentrations. Anti-biofilm activity was tested using test tube and swarming motility test methods and anti-quorum sensing was evaluated using flask incubation test for violacein inhibition production methods. The results showed ethyl acetate extract of E. capensis and its two isolated compounds exhibited antimicrobial, anti-biofilm and anti-quorum sensing activity. Inhibition zones of antimicrobial activities of the extract against S. aureus and C. albicans ranged between 4-20 mm. 10 mg/mL extract showed inhibition of biofilm formation against S. aureus, anti-swarming activities against P. aeruginosa and S. aureus. Inhibition of violacein production against S. aureus, P. aeruginosa, and C. albicans were 72.6%, 67.7% and 69.3% respectively. The ethyl acetate extract, which showed antimicrobials, anti-biofilm, anti-quorum sensing activities, after silica gel column chromatography furnished two compounds namely; diisobutylphtalate and Sandropin B. The chemical structures of these compounds were done using spectroscopic methods including IR and NMR. The isolated compounds also showed strong antimicrobial, anti-biofilm, and anti-quorum sensing activity. This could be useful to manage infectious diseases caused by biofilm forming microorganisms.


2019 ◽  
Vol 82 (3) ◽  
pp. 379-389 ◽  
Author(s):  
ZAIXIANG LOU ◽  
KEKGABILE S. LETSIDIDI ◽  
FUHAO YU ◽  
ZEJUN PEI ◽  
HONGXIN WANG ◽  
...  

ABSTRACT The aim of the present study was to evaluate the quorum sensing (QS) inhibition potential of eugenol and eugenol nanoemulsion against QS-dependent virulence factor production and gene expression, as well as biofilm formation in Pseudomonas aeruginosa. In the current study, eugenol nanoemulsion at a sub-MIC of 0.2 mg/mL specifically inhibited about 50% of the QS-mediated violacein production in Chromobacterium violaceum, as well as the production of N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL) and C4-HSL N-acyl homoserine lactone signal molecules, pyocyanin, and swarming motility in P. aeruginosa. The inhibitive effect of eugenol and its nanoemulsion on the expression of the QS synthase genes was concentration dependent, displaying 65 and 52% expression level for lasI, respectively, and 61 and 45% expression level for rhlI, respectively, at a concentration of 0.2 mg/mL. In addition, the inhibitive effect of eugenol and its nanoemulsion on the expression of the rhlA gene responsible for the production of rhamnolipid was also concentration dependent, displaying 65 and 51% expression level for the rhlA gene, respectively, at a concentration of 0.2 mg/mL. Eugenol and its nanoemulsion also displayed 36 and 63% respective inhibition of biofilm formation by P. aeruginosa at the 0.2 mg/mL concentration. Therefore, the nanoemulsion could be used as a novel QS-based antibacterial and antibiofilm agent for the control of harmful bacteria.


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2672 ◽  
Author(s):  
Emira Noumi ◽  
Abderrahmen Merghni ◽  
Mousa M. Alreshidi ◽  
Ons Haddad ◽  
Gültekin Akmadar ◽  
...  

The problem of antibiotic resistance among pathogens encourages searching for novel active molecules. The aim of the research was to assay the anti-quorum sensing (anti-QS) and antibiofilm potential of Melaleuca alternifolia essential oil and its main constituent, terpinen-4-ol, to prevent the infections due to methicillin-resistant Staphylococcus aureus strains as an alternate to antibiotics. The tea tree oil (TTO) was evaluated for its potential in inhibiting QS-dependent phenomena such as violacein production in Chromobacterium violaceum, swarming motility of Pseudomonas aeruginosa PAO1, and biofilm formation in MRSA strains on glass. The results showed that terpinen-4-ol was able to inhibit MRSA strain biofilm formation on the glass strips by 73.70%. TTO inhibited the violacein production at a mean inhibitory concentration (MIC) value of 0.048 mg/mL by 69.3%. At 100 µg/mL TTO and terpinen-4-ol exhibited inhibition in swarming motility of PAO1 by 33.33% and 25%, respectively. TTO revealed anti-QS and anti-biofilm activities at very low concentrations, but it could be further investigated for new molecules useful for the treatment of MRSA infections.


Author(s):  
Atefeh Jalali ◽  
Mohammadreza Kiafar ◽  
Masih Seddigh ◽  
Mohammad M. Zarshenas

Background: The consumption of natural antioxidants is increasing due to the demand and tendency to natural foods. Punica granatum L. [Punicaceae] is a fruit with various bioactive ingredients. The effectiveness of this plant has been proved against various disorders such as hyperglycemia, hyperlipidemia, blood coagulation, infections, cancer, and dentistry. Among them, there are numerous researches on antimicrobial and antioxidant properties. Subsequently, the present study aimed to compile a review of those properties to outline this herb as a possible natural antioxidant and preservative. Methods: Synchronically, keywords "Punica granatum" with antimicrobial, or antibacterial, antifungal, antiviral, antioxidant and radical scavenging were searched through "Scopus" database up to 31st September 2019. Papers focusing on agriculture, genetics, chemistry, and environmental sciences were excluded and also related papers were collected. Results: Among 201 papers focusing on related activities, 111 papers have dealt with antioxidant activities focusing based on DPPH assay, 59 with antibacterial, on both gram+ and gram- bacteria, 24 with antifungal effects, mostly on Aspergillus niger and Candida albicans, and 7 papers with antiviral activities. There were about 50 papers focusing on in-vivo antioxidant activities of this plant. Conclusion: Taken together, botanical parts of P. granatum have possessed notable radical scavenging and antimicrobial activities that with these properties, this plant can be introduced as a natural safe source of preservative and antioxidant. Accordingly, P. granatum can be applied as excipient with the aforementioned properties in the pharmaceutical and food industries.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 503
Author(s):  
Malika Tassoult ◽  
Djamel Edine Kati ◽  
María África Fernández-Prior ◽  
Alejandra Bermúdez-Oria ◽  
Juan Fernandez-Bolanos ◽  
...  

The study investigated the phenols, sugar and the antioxidant capacities of date fruit extracts obtained by organic solvents and by hydrothermal treatment from six different Algerian cultivars at two ripening stages for the first time. The analyzed cultivars exhibited potent antioxidant properties (ferric reducing antioxidant power (FRAP), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacities) and different phenols regardless of the solvents and the maturity stages. About 18 phenols were identified and quantified, mainly in the hydrothermal extracts. The earlier stages were characterized by high amounts of o-coumaric acid, cinnamic acid and luteolin, with a noticeable absence of quercetin. The tamr stage presented the highest sugar content (78.15–86.85 mg/100 mg dry weight (DW)) with an abundance of glucose. Galactose was present only in some cultivars from the kimri stage (tamjouhert). Uronic acids were mostly detected at the tamr stage (4.02–8.82 mg gallic acid equivalent/100 mg dried weight). The obtained results highlight the potential of using date fruit extracts as natural antioxidants, especially at industrial scales that tend use hydrothermal extraction.


2021 ◽  
Author(s):  
Tuohetisayipu Tuersuntuoheti ◽  
Zhenhua Wang ◽  
Min Zhang ◽  
Fei Pan ◽  
Shan Liang ◽  
...  

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 287
Author(s):  
Yew Rong Kong ◽  
Yong Xin Jong ◽  
Manisha Balakrishnan ◽  
Zhui Ken Bok ◽  
Janice Kwan Kah Weng ◽  
...  

Oxidative stress is a result of disruption in the balance between antioxidants and pro-oxidants in which subsequently impacting on redox signaling, causing cell and tissue damages. It leads to a range of medical conditions including inflammation, skin aging, impaired wound healing, chronic diseases and cancers but these conditions can be managed properly with the aid of antioxidants. This review features various studies to provide an overview on how Carica papaya help counteract oxidative stress via various mechanisms of action closely related to its antioxidant properties and eventually improving the management of various oxidative stress-related health conditions. Carica papaya is a topical plant species discovered to contain high amounts of natural antioxidants that can usually be found in their leaves, fruits and seeds. It contains various chemical compounds demonstrate significant antioxidant properties including caffeic acid, myricetin, rutin, quercetin, α-tocopherol, papain, benzyl isothiocyanate (BiTC), and kaempferol. Therefore, it can counteract pro-oxidants via a number of signaling pathways that either promote the expression of antioxidant enzymes or reduce ROS production. These signaling pathways activate the antioxidant defense mechanisms that protect the body against both intrinsic and extrinsic oxidative stress. To conclude, Carica papaya can be incorporated into medications or supplements to help manage the health conditions driven by oxidative stress and further studies are needed to investigate the potential of its chemical components to manage various chronic diseases.


Planta Medica ◽  
2020 ◽  
Vol 86 (08) ◽  
pp. 520-537 ◽  
Author(s):  
Jürgen Reichling

AbstractPathogenic biofilm-associated bacteria that adhere to biological or nonbiological surfaces are a big challenge to the healthcare and food industries. Antibiotics or disinfectants often fail in an attempt to eliminate biofilms from those surfaces. Based on selected experimental research, this review deals with the potential biofilm-inhibiting, virulence factor-reducing, and biofilm-eradicating activities of essential oils and single essential oil compounds using Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Chromobacterium violaceum as model organisms. In addition, for the bacteria reviewed in this overview, different essential oils and essential oil compounds were reported to be able to modulate the expression of genes that are involved in the formation of autoinducer molecules, biofilms, and virulence factors. The anti-quorum sensing activity of some essential oils and single essential oil compounds was demonstrated using the gram-negative bacterium C. violaceum. Reporter strains of this bacterium produce the violet-colored compound violacein whose synthesis is regulated by quorum sensing autoinducer molecules called acylhomeserinlactones. Of great interest was the discovery that enantiomeric monoterpenes affected the quorum sensing regulation system in different ways. While the (+)-enantiomers of carvone, limonene, and borneol increased violacein formation, their (−)-analogues inhibited violacein production.For the successful eradication of biofilms and the bacteria living inside them, it is absolutely necessary that the lipophilic volatile substances can penetrate into the aqueous channels of biofilms. As shown in recent work, hydrophilic nano-delivery systems encapsulating essential oils/essential oil compounds with antibacterial effects may contribute to overcome this problem.


Sign in / Sign up

Export Citation Format

Share Document