scholarly journals Targeting biofilm inhibition using Quercetin – Interaction with bacterial cell membrane and ROS mediated biofilm control

2018 ◽  
Vol 8 (6) ◽  
pp. 292 ◽  
Author(s):  
Sreelatha Sarangapani ◽  
Ayyavoo Jayachitra

Background: Quercetin is an active nutraceutical ingredient widely distributed in foods, vegetables, fruits, and more. Quercetin is a versatile functional food with extensive protective effects against many infectious and degenerative diseases due to their antioxidant activities. Apsergillus niger is a filamentous fungus and the most abundant mold found in the environment. This fungus has been the source of several bioactive compounds and industrial enzymes through biotransformation.Aim: In this report we emphasized the potential of Aspergillus species for the selective conversion of rutin to quercetin, which involved stereoselective and regiospecific reactions with enhanced production and minimization of the formation of toxic wastes. This fungal microbe was able to transform the complex structure of rutin to quercetin with remarkable catalytic activity for the reaction with high product yield. The quercetin produced demonstrated the ability to inhibit biofilm formation and eradicate established biofilm involving the production of reactive oxygen species (ROS) indicative of membrane activity. These results suggest quercetin may have implications in biofilm control targeting reactive oxygen species as a novel therapeutic strategy.Methods: Quercetin was synthesized by microbial biotransformation recruiting Aspergillus niger. The synthesis of quercetin was compared with the chemical process. Furthermore, the quercetin produced by the biotransformation process was characterized by high performance thin layer liquid chromatography. The quercetin produced was assessed for biological activities. The antimicrobial activity, hemolytic activity, inhibition of biofilm by crystal violet staining, and cell viability by confocal laser scanning microscope was assessed. The membrane interaction effect and oxidant scavenging effect by DPPH, Intracellular ROS release, and lipid peroxidation was measured.Results: Quercetin produced by microbial transformation demonstrated antimicrobial activity against S. aureus by effectively inhibiting the growth and dispersion of preformed biofilms. Quercetin demonstrated a significant free radical scavenging activity and significant inhibition of lipid peroxidation. Significant release of reactive oxygen species was observed in bacterial cells.Conclusion: In conclusion, the bio transformed quercetin exhibited disruptive potential of biofilm formation by preventing cell surface attachment and biofilm growth. Therefore, it can be suggested that the major public health benefits could be achieved by substantially increasing the consumption of quercetin rich foods.

Author(s):  
Shweta Sinha ◽  
Kuldeep Singh ◽  
Akash Ved ◽  
Syed Misbahul Hasan ◽  
Samar Mujeeb

Background: Coumarin is an oxygen-containing compound in medicinal chemistry. Coumarin plays an important role in both natural systems like plants and also in synthetic medicinal applications as drug molecules. Many structurally different coumarin compounds were found to show a big range of similarity with the vital molecular targets for their pharmacological action and small modifications in their structures resulted insignificant changes in their biological activities. Objective: This review gives detailed information about the studies of the recent advances in various pharmacological aspects of coumarins. Method: Various oxygen-containing heterocyclic compounds represented remarkable biological significances. The fused aromatic oxygen-heterocyclic nucleus is able to change its electron density; thus changing the chemical, physical and biological properties respectively due to its multiple binding modes with the receptors, which play crucial role in pharmacological screening of drugs. A number of heterocyclic compounds have been synthesized which have their nucleus derived from various plants and animals. In coumarins, benzene ring is fused with pyrone nucleus which provides stability to the nucleus. Coumarins have shown a wide range of pharmacological activities such as anti-tumour, anti-coagulant, anti-inflammatory, anti-oxidant, antiviral, anti-malarial, anti-HIV and antimicrobial activity etc. Results: Reactive oxygen species like superoxide anion, hydroxyl radical and hydrogen peroxide are a type of unstable molecule that contains oxygen, which reacts with other molecules in the cell during the metabolism process but it may produce cytotoxicity when reactive oxygen species increase in number, by the damage of biological macromolecules. Hydroxyl radical (˙OH), is a strong oxidizing agent and it is responsible for the cytotoxicity by oxygen in different plants, animals and other microbes. coumarin is the oldest and effective compound having antimicrobial activity, anti-inflammatory, antioxidant, antidepressant activity, analgesic, anticonvulsant activity, etc. Naturally existing coumarin compounds act against SARS-CoV-2 by preventing viral replication through the targeting on active site against the Mpro target protein. Conclusion: This review highlights the different biological activities of coumarin derivatives. In this review we provide an updated summary of the researches which are related to recent advances in biological activities of coumarins analogue and their most recent activities against COVID -19. Natural compounds act as a rich resource for novel drug development against various SARS-CoV-2 viral strains including viruses like herpes simplex virus, influenza virus, human immunodeficiency virus, hepatitis B and C viruses, middle east respiratory syndrome and severe acute respiratory syndrome.


2012 ◽  
Vol 48 (4) ◽  
pp. 659-665 ◽  
Author(s):  
Aline Emmer Ferreira Furman ◽  
Railson Henneberg ◽  
Priscila Bacarin Hermann ◽  
Maria Suely Soares Leonart ◽  
Aguinaldo José do Nascimento

Sickle cell disease promotes hemolytic anemia and occlusion of small blood vessels due to the presence of high concentrations of hemoglobin S, resulting in increased production of reactive oxygen species and decreased antioxidant defense capacity. The aim of this study was to evaluate the protective action of a standardized extract of Ginkgo biloba (EGb 761), selected due to its high content of flavonoids and terpenoids, in erythrocytes of patients with sickle cell anemia (HbSS, SS erythrocytes) subjected to oxidative stress using tert-butylhydroperoxide or 2,2-azobis-(amidinepropane)-dihydrochloride, in vitro. Hemolysis indexes, reduced glutathione, methemoglobin concentrations, lipid peroxidation, and intracellular reactive oxygen species were determined. SS erythrocytes displayed increased rates of oxidation of hemoglobin and membrane lipid peroxidation compared to normal erythrocytes (HbAA, AA erythrocytes), and the concentration of EGb 761 necessary to achieve the same antioxidant effect in SS erythrocytes was at least two times higher than in normal ones, inhibiting the formation of intracellular reactive oxygen species (IC50 of 13.6 µg/mL), partially preventing lipid peroxidation (IC50 of 242.5 µg/mL) and preventing hemolysis (IC50 of 10.5 µg/mL). Thus, EGb 761 has a beneficial effect on the oxidative status of SS erythrocytes. Moreover, EGb 761 failed to prevent oxidation of hemoglobin and reduced glutathione at the concentrations examined.


2012 ◽  
Vol 1 (1) ◽  
pp. 18
Author(s):  
Amrit Kaur Bansal ◽  
Ranjna Sundhey Cheema ◽  
Vinod Kumar Gandotra

The aim of this paper was to investigate the antioxidant effect of Mn2+ (200 mM) on the sperm capacitation and acrosome reaction of fresh and chilled cattle bull semen. It has been found that Mn2+ supplementation improves (P≤0.05) the motility at 0, 2, 4 and 6 h of incubation. MDA (malondialdehyde), end product of lipid peroxidation, decreases significantly (P≤0.05) with the supplementation of manganese at 0- and 6-hr of incubation both in fresh and chilled semen. Manganese also increases acrosome reaction significantly (P≤0.05) both in fresh and chilled semen at 0, 4 and 6 h of incubation. Therefore, our findings suggest the role of Mn2+supplementation in improving the quality of cattle bull semen by its scavenging property<em> i.e.</em> reduction in the production of reactive oxygen species during its storage at 4°C or incubation at 37°C for capacitation.


2018 ◽  
Vol 64 (7) ◽  
pp. 455-464 ◽  
Author(s):  
Géssika Silva Souza ◽  
Lais Pessanha de Carvalho ◽  
Edésio José Tenório de Melo ◽  
Valdirene Moreira Gomes ◽  
André de Oliveira Carvalho

Plant defensins are plant antimicrobial peptides that present diverse biological activities in vitro, including the elimination of Leishmania amazonensis. Plant defensins are considered promising candidates for the development of new drugs. This protozoan genus has great epidemiological importance and the mechanism behind the protozoan death by defensins is unknown, thus, we chose L. amazonensis for this study. The aim of the work was to analyze the possible toxic mechanisms of Vu-Defr against L. amazonensis. For analyses, the antimicrobial assay was repeated as previously described, and after 24 h, an aliquot of the culture was tested for viability, membrane perturbation, mitochondrial membrane potential, reactive oxygen species (ROS) and nitric oxide (NO) inductions. The results of these analyses indicated that after interaction with L. amazonensis, the Vu-Defr causes elimination of promastigotes from culture, membrane perturbation, mitochondrial membrane collapse, and ROS induction. Our analysis demonstrated that NO is not produced after Vu-Defr and L. amazonensis interaction. In conclusion, our work strives to help to fill the gap relating to effects caused by plant defensins on protozoan and thus better understand the mechanism of action of this peptide against L. amazonensis.


2015 ◽  
pp. 849-856 ◽  
Author(s):  
M. VOKURKOVÁ ◽  
H. RAUCHOVÁ ◽  
L. ŘEZÁČOVÁ ◽  
I. VANĚČKOVÁ ◽  
J. ZICHA

Hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play an important role in brain control of blood pressure (BP). One of the important mechanisms involved in the pathogenesis of hypertension is the elevation of reactive oxygen species (ROS) production by nicotine adenine dinucleotide phosphate (NADPH) oxidase. The aim of our present study was to investigate NADPH oxidase-mediated superoxide (O2-) production and to search for the signs of lipid peroxidation in hypothalamus and medulla oblongata as well as in renal medulla and cortex of hypertensive male rats transgenic for the murine Ren-2 renin gene (Ren-2 TGR) and their age-matched normotensive controls ‒ Hannover Sprague Dawley rats (HanSD). We found no difference in the activity of NADPH oxidase measured as a lucigenin-mediated O2- production in the hypothalamus and medulla oblongata. However, we observed significantly elevated NADPH oxidase in both renal cortex and medulla of Ren-2 TGR compared with HanSD. Losartan (LOS) treatment (10 mg/kg body weight/day) for 2 months (Ren-2 TGR+LOS) did not change NADPH oxidase-dependent O2- production in the kidney. We detected significantly elevated indirect markers of lipid peroxidation measured as thiobarbituric acid-reactive substances (TBARS) in Ren-2 TGR, while they were significantly decreased in Ren-2 TGR+LOS. In conclusion, the present study shows increased NADPH oxidase activities in renal cortex and medulla with significantly increased TBARS in renal cortex. No significant changes of NADPH oxidase and markers of lipid peroxidation were detected in the studied brain regions.


2020 ◽  
Vol 332 ◽  
pp. 118-129
Author(s):  
Kush N. Shah ◽  
Parth N. Shah ◽  
Andrew R. Mullen ◽  
Qingquan Chen ◽  
Marie R. Southerland ◽  
...  

2018 ◽  
Vol 13 (5) ◽  
pp. 239-247 ◽  
Author(s):  
M. M. Rohman ◽  
M. R. Islam ◽  
B. M. Mahmuda ◽  
S. Begum ◽  
O. A. Fakir ◽  
...  

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