Olive leaf extract (OLE) is used in traditional medicine as a food supplement and as an over-the-counter drug for a variety of its effects, including anti-inflammatory and anti-atherosclerotic ones. ...Mechanisms through which OLE could modulate these pathways in human vasculature remain largely unknown. Serum amyloid A (SAA) plays a causal role in atherosclerosis and cardiovascular diseases and induces pro-inflammatory and pro-adhesive responses in human coronary artery endothelial cells (HCAEC). Within this study we explored whether OLE can attenuate SAA-driven responses in HCAEC. HCAEC were treated with SAA (1,000 nM) and/or OLE (0.5 and 1 mg/ml). The expression of adhesion molecules VCAM-1 and E-selectin, matrix metalloproteinases (MMP2 and MMP9) and microRNA 146a, let-7e, and let-7g (involved in the regulation of inflammation) was determined by qPCR. The amount of secreted IL-6, IL-8, MIF, and GRO-α in cell culture supernatants was quantified by ELISA. Phosphorylation of NF-κB was assessed by Western blot and DNA damage was measured using the COMET assay. OLE decreased significantly released protein levels of IL-6 and IL-8, as well as mRNA expression of E-selectin in SAA-stimulated HCAEC and reduced MMP2 levels in unstimulated cells. Phosphorylation of NF-κB (p65) was upregulated in the presence of SAA, with OLE significantly attenuating this SAA-induced effect. OLE stabilized SAA-induced upregulation of microRNA-146a and let-7e in HCAEC, suggesting that OLE could fine-tune the SAA-driven activity of NF-κB by changing the microRNA networks in HCAEC. SAA induced DNA damage and worsened the oxidative DNA damage in HCAEC, whereas OLE protected HCAEC from SAA- and H
O
-driven DNA damage. OLE significantly attenuated certain pro-inflammatory and pro-adhesive responses and decreased DNA damage in HCAEC upon stimulation with SAA. The reversal of SAA-driven endothelial activation by OLE might contribute to its anti-inflammatory and anti-atherogenic effects in HCAEC.
Abstract Systemic oxidative stress stemming from increased free radical production and reduced antioxidant capacity are common characteristics of obese individuals. Using hydrogen peroxide (H2O2) to ...induce DNA damage in vitro, in peripheral blood mononuclear cells (PBMCs) from obese subjects and controls, the DNA protective ability of dihidroqercetin (DHQ) and biochaga (B) alone or in combination, were evaluated. The effects of DHQ and B were estimated under two experimental conditions: pre-treatment, where cells were pre-incubated with the substances prior to H2O2 exposure; and post-treatment when cells were first exposed to H2 H2O2, and further treated with the compounds. DNA damage was evaluated using the comet assay. The results of pre- and post-treatment showed a significant decrease in DNA damage produced by H2O2 in the obese group. This decrease was not significant in control group probably due to a small number of subjects in this pilot study. More prominent attenuation was noted in the pre-treatment with DHQ (250 μg/ml). Analysis of antioxidant properties revealed that DHQ’s remarkable reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, and potent∙OH scavenging properties may contribute to strong attenuation of H2O2-induced DNA damage. Also, B showed strong reducing power, DPPH, and ∙OH scavenging ability, while reducing power and DPPH scavenger effects were increased in the presence of DHQ. Conclusively, DHQ and B may reduce H2O2-induced DNA damage in PBMCs from obese subjects when challenged in vitro, and could be valuable tools in future research against oxidative damage-related conditions.
•IA is blend of six species of medicinal mushrooms.•Significant antigenotoxic effects of IA were detected by comet assay in vitro.•Evaluation of IA antioxidant properties showed remarkable OH ...scavenging ability.
Immune Assist (IA) is produced from extract of six species of medical mushrooms: Agaricus blazei - Cordyceps sinensis - Grifola frondosa - Ganoderma lucidum - Coriolus versicolor - Lentinula edodes. The genoprotective potential of IA was evaluated for the first time. Significant antigenotoxic effects were detected in human peripheral blood cells against H2O2 induced DNA damage, in the pretreatment and in the posttreatment. The most efficient concentration of IA in pretreatment was 500 μg/mL, while in posttreatment it was the concentration of 250 μg/mL. Kinetics of attenuation of H2O2 induced DNA damage in posttreatment with the optimal concentration of IA showed significant decrease in the number of damaged cells at all time periods (15–60 min), reaching the greatest reduction after 15 and 45 min. Remarkable ·OH scavenging properties and moderate reducing power, together with the modest DPPH scavenging activity, could be responsible for the great attenuation of DNA damage after 15 min of exposure to IA, while reduction of DNA damage after 45 min could be the result in additional stimulation of the cell’s repair machinery. Our results suggest that IA displayed antigenotoxic and antioxidant properties. A broader investigation of its profile in biological systems is needed.
The acute toxicity of surface-modified TiO2 nanoparticles (NPs) with caffeic acid (CA) was compared with those of its separate constituents (free CA and bare TiO2 NPs) upon their oral administration ...in laboratory mice. Prior to in vivo experiments, the interfacial charge transfer (ICT) complex between surface Ti atoms and CA is thoroughly characterized. Composition and stability constants of ICT complex were determined using Job's method and Banesi-Hildebrand analysis, respectively. The experimental data were supported with quantum chemical calculations based on density functional theory (DFT). Acute toxicity signs, including biochemical alterations and extensive histopathological changes in the liver tissue of mice were detected 14 days after oral administration of bare TiO2 NPs. However, the clinical signs of toxicity, the fractional contribution of organs, biochemical parameters of liver and kidney function, and histopathological changes in liver upon treatment with surface-modified TiO2 NPs with CA were not observed. Also, the genotoxic potential of the ICT complex and its constituents were evaluated in leukocytes of whole blood cells in vivo by comet assay. Both, bare and surface-modified TiO2 NPs did not display DNA damaging effect in time frame of 24 h upon their oral administration in mice.
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•Acute toxicity signs detected upon oral administration of pristine TiO2 nanoparticles (NPs) in mice.•Toxic action of TiO2 NPs is less upon formation of interfacial charge transfer (ICT) complex with caffeic acid (CA).•Detailed experimental and quantum chemical characterization of ICT complex between TiO2 NPs and CA.
Abstract
Dry olive leaf extract (DOLE) and its active component oleuropein (OLE) were applied as reducing and stabilizing agents to prepare colloidal 20–25 nm silver nanoparticles (Ag NPs). The Ag ...NPs were characterized using transmission electron microscopy, X-ray diffraction analysis, and absorption spectroscopy. The cytotoxic actions of coated Ag NPs, and their inorganic and organic components, were examined against trophoblast cells and human peripheral blood lymphocytes (PBLs), Gram-positive, Gram-negative bacteria, and yeast. The genotoxic potential was evaluated in PBLs in vitro with the comet assay. Ag/DOLE and Ag/OLE induced cytotoxic effects in both types of cells after 24 h exposure when silver concentrations were 0.025–0.2 mM. However, the most pronounced cytotoxicity exhibits Ag/OLE. Both colloids also caused reduced ROS production in both cell types at 0.1 mM and 0.2 mM, while bare Ag NPs did not alter ROS levels at any of the conditions. Functionalized Ag/DOLE and Ag/OLE did not show genotoxic effects in PBLs, while bare AgNPs increased DNA damage significantly only at 0.2 mM. Regarding the antimicrobial effects, the Ag/OLE had MIC values for all evaluated microorganisms from 0.0625 to less than 0.0312 mM. Also, the antimicrobial effect of Ag/DOLE was significantly higher on Gram-negative bacteria and yeast than on Gram-positive bacteria. Obtained results indicate that Ag/OLE induced the most pronounced biological effects, beneficial for its application as an antimicrobial agent, but with potential risks from exposure to high concentrations that could induce cytotoxicity in healthy human cells.
Graphical Abstract
Graphical Abstract
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•Antigenotoxic potential of DOLE was investigated on the human whole blood in vitro, using comet assay.•E2 and DES were used as DNA damage inducers, expressing a genotoxic ...effect.•DOLE exhibited antigenotoxic properties.
Phenolic groups of steroidal or nonsteroidal estrogens can redox cycle, leading to oxidative stress, where creation of reactive oxygen species are recognized as the main mechanism of their DNA damage properties. Dry olive (Olea europaea L.) leaf extract is known to contain bioactive and antioxidative components and to have an ability to modulate the effects of various oxidants in cells. The main goal of this study was to investigate antigenotoxic potential of a standardized dry olive leaf extract on DNA damage induced by 17β-estradiol and diethylstilbestrol in human whole blood cells in vitro, using comet assay. Our results indicated that both hormones showed a genotoxic effect at a concentration of 100 μM (P < 0.05, n = 6). Dry olive leaf extract was efficient in reducing number of cells with estrogen-induced DNA damage at tested concentrations (0.125, 0.5 and 1 mg/mL) (P < 0.05, n = 6) and under two experimental protocols, pre-treatment and post-treatment, exhibiting antigenotoxic properties. Analysis of antioxidant properties of the extract revealed moderate ABTS radical scavenging properties and reducing power. Overall, our results suggested that the protective potential of dry olive leaf extract could arise from the synergistic effect of its scavenging activity and enhancement of the cells' antioxidant capacity.
The antibacterial performance and cytotoxic examination of in situ prepared silver nanoparticles (Ag NPs), on inorganic-organic hybrid nanopowder consisting of zirconium dioxide nanoparticles (ZrO2 ...NPs) and dihydroquercetin (DHQ), was performed against Gram (−) bacteria Escherichia coli and Gram (+) bacteria Staphylococcus aureus, as well as against human cervical cancer cells HeLa and healthy MRC-5 human cells. The surface modification of ZrO2 NPs, synthesized by the sol-gel method, with DHQ leads to the interfacial charge transfer (ICT) complex formation indicated by the appearance of absorption in the visible spectral range. The prepared samples were thoroughly characterized (TEM, XRD, reflection spectroscopy), and, in addition, the spectroscopic observations are supported by the density functional theory (DFT) calculations using a cluster model. The concentration- and time-dependent antibacterial tests indicated a complete reduction of bacterial species, E. coli and S. aureus, for all investigated concentrations of silver (0.10, 0.25, and 0.50 mg/mL) after 24 h of contact. On the other side, the functionalized ZrO2 NPs with DHQ, before and after deposition of Ag NPs, do not display a significant decrease in the viability of HeLa MRC-5 cells in any of the used concentrations compared to the control.
The CaNa2EDTA chelation therapy is often practiced with antioxidant supplementation. Dry olive leaf extract (DOLE) is natural product with antioxidant and DNA protective properties. The effects of ...DOLE on the levels of DNA damage were investigated ex vivo in peripheral blood lymphocytes (PBLs) of 19 workers occupationally exposed to lead (Pb), before and after CaNa2EDTA chelation therapy.
DOLE demonstrated pronounced radical scavenging activity in concentrations ≥1 mg/mL, and showed no genotoxicity per se, in concentrations 0.125–1 mg/mL. The level of DNA damage in PBLs of workers before chelation therapy was elevated (24.21 ± 14.26) compared to controls (6.0 ± 3.37). The incubation of PBLs before chelation therapy with selected concentration of DOLE lead to a severe increase of DNA damage (64.03 ± 20.96), exhibiting prooxidant rather than antioxidant effect. After the five-day CaNa2EDTA chelation regimen, DNA damage in PBLs of workers decreased (8.26 ± 4.62) significantly compared to baseline. Treatment of PBLs with DOLE after chelation, again produced high level of damage (41.82 ± 23.17) and the acute prooxidant effects of DOLE remained, but, DNA damage was less severe than before chelation. The DOLE exhibits prooxidant effect in presence of Pb in lymphocytes of exposed workers, and its effect is less pronounced following the removal of Pb after standard chelation therapy.
•The CaNa2EDTA chelation is a standard therapy for lead (Pb) intoxication, often practiced with antioxidant supplementation.•Effects of dry olive leaf extract on lymphocytes DNA integrity, before and after CaNa2EDTA chelation therapy were explored.•Five-day CaNa2EDTA chelation regimen decreased DNA damage in lymphocytes of Pb exposed workers.•Dry olive leaf extract exhibited prooxidant effect in lymphocytes of Pb exposed workers, before and after chelation treatment.•Prooxidant effect of dry olive leaf extract was less pronounced following the removal of Pb after chelation therapy.
L. is a well-known aromatic plant used in traditional medicine and the food and cosmetics industry. The aim of this study is to assess the antioxidant, genotoxic, antigenotoxic and cytotoxic ...properties of characterized hyssop essential oils and methanol extracts. Chemical composition was analyzed by gas chromatography - mass spectrometry (GC-MS) and liquid chromatography with diode array detection and mass spectrometry (LC-DAD-MS), respectively. Antioxidant activity was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) tests; genotoxic and antigenotoxic activity were examined by the comet assay, while cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide dye (MTT) test against tumor cell lines (SW480, MDA-MB 231, HeLa) and non-transformed human lung fibroblast cell lines (MRC-5). The essential oils were rich in monoterpene hydrocarbons (e.g., limonene; 7.99-23.81%), oxygenated monoterpenes (1,8-cineole; 38.19-67.1%) and phenylpropanoids (methyl eugenol; 0.00-28.33%). In methanol extracts, the most abundant phenolics were chlorogenic and rosmarinic acid (23.35-33.46 and 3.53-17.98 mg/g, respectively). Methanol extracts expressed moderate to weak antioxidant activity (DPPH IC
= 56.04-199.89 µg/mL, FRAP = 0.667-0.959 mmol Fe
/g). Hyssop preparations significantly reduced DNA damage in human whole blood cells, induced by pretreatment with hydrogen peroxide. Methanol extracts exhibited selective and potent dose- and time-dependent activity against the HeLa cell line. Results of the current study demonstrated notable
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medicinal potential, which calls for further investigation.
The ability of Agaricus blazei mushroom in its dried and powdered mycelial form was evaluated for its antigenotoxic properties for the first time. Antigenotoxic effects in human peripheral blood ...cells against H2O2-induced DNA damage were examined in pretreatment and posttreatment protocol by comet assay. The results showed better antigenotoxic properties of Agaricus blazei on the interventional level, respectively, after treatment. Agaricus blazei in concentration of 250 μg/mL after treatment was most efficient in regard to its action against DNA damage. The evaluation of repair kinetics showed decrease in H2O2 induced DNA damage 15 min after the application of A. blazei, reaching the maximum potency after 30 min. Analysis of antioxidant properties of Agaricus blazei revealed strong OH• scavenging properties and moderate reducing power, while its DPPH scavenging ability was weak. In regard to our findings, we can conclude that our preliminary results demonstrated antigenotoxic properties of Agaricus blazei and its strong OH• scavenging ability. Mechanisms underlying its properties should be further evaluated in in vivo studies.
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