Oleuropein Stimulates Migration of Human Trophoblast Cells and Expression of Invasion-Associated Markers.

Successful pregnancy establishment requires highly synchronized cross talk between the invasive trophoblast cells and the receptive maternal endometrium. Any disturbances in this tightly regulated process may lead to pregnancy complications. Local factors such as nutrients, hormones, cytokines and reactive oxygen species modulate the invasion of extravillous trophoblasts through critical signaling cascades. Epidemiological studies strongly indicate that a Mediterranean diet can significantly impact molecular pathways during placentation. Therefore, the aim of the current study was to examine whether oleuropein (OLE), one of the main compounds of the Mediterranean diet, may influence trophoblast cell adhesion and migration, as well as the expression of invasion-associated molecular markers and inflammatory pathways fostering these processes. HTR-8/SVneo cells were incubated with OLE at selected concentrations of 10 and 100 µM for 24 h. Results showed that OLE did not affect trophoblast cell viability, proliferation and adhesion after 24 h in in vitro treatment. The mRNA expression of integrin subunits α1, α5 and ß1, as well as matrix-degrading enzymes MMP-2 and -9, was significantly increased after treatment with 10 µM OLE. Furthermore, OLE at a concentration of 10 µM significantly increased the protein expression of integrin subunits α1 and ß1. Also, OLE inhibited the activation of JNK and reduced the protein expression of COX-2. Finally, a lower concentration of OLE 10 µM significantly stimulated migration of HTR-8/SVneo cells. In conclusion, the obtained results demonstrate the effects of OLE on the function of trophoblast cells by promoting cell migration and stimulating the expression of invasion markers. As suggested from results, these effects may be mediated via inhibition of the JNK signaling pathway.

IL-6 and IL-8: An Overview of Their Roles in Healthy and Pathological Pregnancies.

Interleukin-6 (IL-6) is an acknowledged inflammatory cytokine with a pleiotropic action, mediating innate and adaptive immunity and multiple physiological processes, including protective and regenerative ones. IL-8 is a pro-inflammatory CXC chemokine with a primary function in attracting and activating neutrophils, but also implicated in a variety of other cellular processes. These two ILs are abundantly expressed at the feto-maternal interface over the course of a pregnancy and have been shown to participate in numerous pregnancy-related events. In this review, we summarize the literature data regarding their role in healthy and pathological pregnancies. The general information related to IL-6 and IL-8 functions is followed by an overview of their overall expression in cycling endometrium and at the feto-maternal interface. Further, we provide an overview of their involvement in pregnancy establishment and parturition. Finally, the implication of IL-6 and IL-8 in pregnancy-associated pathological conditions, such as pregnancy loss, preeclampsia, gestational diabetes mellitus and infection/inflammation is discussed.

Olive leaf extract attenuates adriamycin-induced focal segmental glomerulosclerosis in spontaneously hypertensive rats via suppression of oxidative stress, hyperlipidemia, and fibrosis.

Olive (Olea europaea L.) leaf extract (OLE) possesses powerful antioxidant, antihyperlipidemic, and anti-inflammatory properties. The aim was to investigated the effects of OLE on the hyperlipidemia, antioxidant defense, heme oxygenase/biliverdin reductase (HO/BVR) pathway, inflammation, and fibrosis in spontaneously hypertensive rats with focal segmental glomerulosclerosis (FSGS, a progressive form of chronic kidney disease) induced by adriamycin (2 mg/kg, i.v., twice in a 21-day period). Daily treatment of OLE (80 mg/kg, p.o.) for 6 weeks suppressed protein oxidation and lipid peroxidation (p < .01 and p < .001, respectively), significantly increased antioxidant enzymes activities and normalized antioxidant capacity, leading to the improvement of antioxidant defense independently of the HO/BVR pathway. Furthermore, the values of triglycerides (p < .01), total, and low-density lipoprotein cholesterol (p < .05, both) were improved by OLE. OLE strongly prevented glomerulosclerosis, interstitial inflammation, and fibrosis (renal injury score, FSGS: 8 ± 0.45 vs. FSGS+OLE: 4.20 ± 1.07; p < .01), as evidenced by normalized fibronectin content (p < .001), suppressed interstitial inflammatory cells infiltration and collagen deposition, without changing cytokines expressions. OLE decreased blood pressure with a tendency to reduce urine albumin loss. These data suggest that OLE may be effective in slowing down the progression of FSGS.

Galectins in Early Pregnancy and Pregnancy-Associated Pathologies.

Galectins are a family of conserved soluble proteins defined by an affinity for ß-galactoside structures present on various glycoconjugates. Over the past few decades, galectins have been recognized as important factors for successful implantation and maintenance of pregnancy. An increasing number of studies have demonstrated their involvement in trophoblast cell function and placental development. In addition, several lines of evidence suggest their important roles in feto-maternal immune tolerance regulation and angiogenesis. Changed or dysregulated galectin expression is also described in pregnancy-related disorders. Although the data regarding galectins' clinical relevance are still at an early stage, evidence suggests that some galectin family members are promising candidates for better understanding pregnancy-related pathologies, as well as predicting biomarkers. In this review, we aim to summarize current knowledge of galectins in early pregnancy as well as in pregnancy-related pathologies.

Dry Olive Leaf Extract in Combination with Methotrexate Reduces Cell Damage in Early Rheumatoid Arthritis Patients-A Pilot Study.

The effects of co-administration of dry olive leaf extract (DOLE) with standard methotrexate (MTX) therapy on the parameters of cell damage and inflammation in patients with early and long-term rheumatoid arthritis (RA) were evaluated at baseline, 3 and 6 weeks. Patients were assigned to groups: the early phase RA group on MTX monotherapy (E MTX), and the two RA groups that received co-treatment with DOLE and MTX: early (E MTX + DOLE) and long-term phase patients (L-t MTX+ DOLE). Baseline values indicated increased parameters of cell damage and disruption of redox balance in all groups. After three weeks the E MTX + DOLE group maintained high catalase activity, exhibited decrease of lipid peroxidation and protein damage indicators-thiols and nitrites, while levels of DNA damage and pro-inflammatory interleukin-6 were significantly reduced. In E MTX group catalase activity remained unaltered while significant lipid peroxidation and DNA damage reductions were seen only after six weeks. L-t MTX + DOLE group showed only modest alterations of cell damage parameters during six weeks. Combined administration of DOLE with MTX contributes to faster reduction of cell damage, restores oxidative balance and improves interleukin-6 suppression during high disease activity in early phase RA, but not in long term patients. Copyright © 2016 John Wiley & Sons, Ltd.

Oleuropein Attenuates Oxidative Stress in Human Trophoblast Cells.

Olive-derived bioactive compound oleuropein was evaluated against damage induced by hydrogen peroxide in human trophoblast cells in vitro, by examining the changes in several markers implicated in oxidative stress interactions in the placenta. Trophoblast HTR-8/SVneo cells were preincubated with OLE at 10 and 100 µM and exposed to H2O2, as a model of oxidative stress. Protein and lipid peroxidation, as well as antioxidant enzymes' activity, were determined spectrophotometrically, and DNA damage was evaluated by comet assay. iNOS protein expression was assessed by Western blot, while the mRNA expression of pro- and anti-apoptotic genes BAX and BCL2 and transcription factor NFE2L2, as well as cytokines IL-6 and TNF α were determined by qPCR. Oleuropein demonstrated cytoprotective effects against H2O2 in trophoblast cells by significantly improving the antioxidant status and preventing protein and lipid damage, as well as reducing the iNOS levels. OLE reduced the mRNA expression of IL-6 and TNF α, however, it did not influence the expression of NFE2L2 or the BAX/BCL2 ratio after H2O2 exposure. Oleuropein per se did not lead to any adverse effects in HTR-8/SVneo cells under the described conditions, confirming its safety in vitro. In conclusion, it significantly attenuated oxidative damage and restored antioxidant functioning, confirming its protective role in trophoblast.

Caffeic acid protects human trophoblast HTR-8/SVneo cells from H2O2-induced oxidative stress and genotoxicity.

Caffeic acid is highlighted as one of the major phenolic compounds present in foods with known antioxidant activity. This phenolic is among commonly consumed substances in everyday diet of pregnant women. However, there is not enough information on its effects during pregnancy, especially the most vulnerable early stage. Extravillous trophoblast cells are specific cells of the placenta that come in direct contact with maternal uterine tissue. Through this study we investigated the cytoprotective effects of caffeic acid on H2O2-induced oxidative damage in first trimester extravillous trophoblast cell line HTR-8/SVneo. Investigated concentrations (1-100 µM) of caffeic acid showed neither cytotoxic nor genotoxic effects on HTR-8/SVneo cells. The treatment with caffeic acid 100 µM significantly increased the percentage of cells in G2/M phase of the cell cycle, compared to non-treated cells. Pretreatment with caffeic acid (10 and 100 µM) attenuated oxidative DNA damage significantly, reduced cytotoxicity, protein and lipid peroxidation, and restored antioxidant capacity in trophoblast cells following H2O2 exposure. This beneficial outcome is probably mediated by the augmentation of GSH and effective ROS scavenging by caffeic acid. These promising results require further investigations to reveal the additional mechanisms/pathways and confirmation through studies in vivo.

The Role of Dietary Polyphenols in Pregnancy and Pregnancy-Related Disorders.

Polyphenols are a group of phytochemicals with extensive biological functions and health-promoting potential. These compounds are present in most foods of plant origin and their increased widespread availability through the intake of nutritional supplements, fortified foods, and beverages, has also led to increased exposure throughout gestation. In this narrative review, we focus on the role of polyphenols in both healthy and pathological pregnancy. General information related to their classification and function is followed by an overview of their known effects in early-pregnancy events, including the current insights into molecular mechanisms involved. Further, we provide an overview of their involvement in some of the most common pregnancy-associated pathological conditions, such as preeclampsia and gestational diabetes mellitus. Additionally, we also discuss the estimated possible risk of polyphenol consumption on pregnancy outcomes. The consumption of dietary polyphenols during pregnancy needs particular attention considering the possible effects of polyphenols on the mechanisms involved in maternal adaptation and fetal development. Further studies are strongly needed to unravel the in vivo effects of polyphenol metabolites during pregnancy, as well as their role on advanced maternal age, prenatal nutrition, and metabolic risk of the offspring.

Multiple antimelanoma potential of dry olive leaf extract.

Various constituents of the olive tree (Olea europaea) have been traditionally used in the treatment of infection, inflammation, prevention of chronic diseases, cardiovascular disorders and cancer. The anticancer potential of dry olive leaf extract (DOLE) represents the net effect of multilevel interactions between different biologically active compounds from the extract, cancer cells and conventional therapy. In this context, it was of primary interest to evaluate the influence of DOLE on progression of the highly malignant, immuno- and chemoresistant type of skin cancer-melanoma. DOLE significantly inhibited proliferation and subsequently restricted clonogenicity of the B16 mouse melanoma cell line in vitro. Moreover, late phase tumor treatment with DOLE significantly reduced tumor volume in a syngeneic strain of mice. DOLE-treated B16 cells were blocked in the G(0) /G(1) phase of the cell cycle, underwent early apoptosis and died by late necrosis. At the molecular level, the dying process started as caspase dependent, but finalized as caspase independent. In concordance, overexpression of antiapoptotic members of the Bcl-2 family, Bcl-2 and Bcl-XL, and diminished expression of their natural antagonists, Bim and p53, were observed. Despite molecular suppression of the proapoptotic process, DOLE successfully promoted cell death mainly through disruption of cell membrane integrity and late caspase-independent fragmentation of genetic material. Taken together, the results of this study indicate that DOLE possesses strong antimelanoma potential. When DOLE was applied in combination with different chemotherapeutics, various outcomes, including synergy and antagonism, were observed. This requires caution in the use of the extract as a supplementary antitumor therapeutic.

Strawberry (Fragaria ananassa duch.) Alba extract attenuates DNA damage in lymphocytes of patients with Alzheimer's disease.

Increased levels of oxidative stress and oxidative DNA damage are common features in the pathology of Alzheimer's disease (AD) found in neurons and peripheral cells like peripheral blood lymphocytes (PBL). Natural products such as strawberry cultivar Alba are an important source of bioactive nutrients that could help in lowering both the oxidative stress and DNA damage levels. The objective was to estimate the effects of Alba extract on DNA damage in peripheral blood lymphocytes of sporadic AD (aged 60-84 years) patients, and healthy elderly (aged 69-83 years) and young (aged 21-30 years) individuals in in vitro conditions. Comet assay was used as a sensitive technique for the evaluation of PBL DNA damage levels. Reduction of basal DNA damage level in PBL was shown in the young group after the incubation with Alba extract ranging from 25 to 200 µg/ml, with 100 µg/ml being the most effective concentration. Selected Alba extract of 100 µg/ml was further used for PBL treatment of AD and healthy elderly age matched group, displaying potential to significantly attenuate DNA damage levels in both groups (p < .05). Alba extract displayed biological activity against oxidative DNA damage, suggesting that its functional ingredients may have beneficial health effects. PRACTICAL APPLICATIONS: The data obtained in this preliminary study displayed that strawberry Alba extract is efficient against DNA damage induced by endogenous and exogenous oxidative stress in peripheral blood lymphocytes of Alzheimer`s disease in vitro. An active area of future research of Alba cultivar should be to determine the trials in in vivo systems. Our findings also suggest that Alba cultivar's functional ingredients potentially may have beneficial health effects in AD.

Surface-modified ZrO2 nanoparticles with caffeic acid: Characterization and in vitro evaluation of biosafety for placental cells.

The toxicity of hybrid nanoparticles, consisting of non-toxic components, zirconium dioxide nanoparticles (ZrO2 NPs), and caffeic acid (CA), was examined against four different cell lines (HTR-8 SV/Neo, JEG-3, JAR, and HeLa). Stable aqueous ZrO2 sol, synthesized by forced hydrolysis, consists of 3-4 nm in size primary particles organized in 30-60 nm in size snowflake-like particles, as determined by transmission electron microscopy and direct light scattering measurements. The surface modification of ZrO2 NPs with CA leads to the formation of an interfacial charge transfer (ICT) complex followed by the appearance of absorption in the visible spectral range. The spectroscopic observations are complemented with the density functional theory calculations using a cluster model. The ZrO2 NPs and CA are non-toxic against four different cell lines in investigated concentration range. Also, ZrO2 NPs promote the proliferation of HTR-8 SV/Neo, JAR, and HeLa cells. On the other hand, hybrid ZrO2/CA NPs induced a significant reduction of the viability of the JEG-3 cells (39 %) for the high concentration of components (1.6 mM ZrO2 and 0.4 mM CA).

Dried leaf extract of Olea europaea ameliorates islet-directed autoimmunity in mice.

The health-promoting effects of various constituents of the olive tree (Olea europaea) are mainly associated with hypoglycaemic and insulin-sensitising activities and have been widely demonstrated in the metabolic syndrome and type 2 diabetes. However, their biological activity in autoimmune type 1 diabetes (T1D) is poorly characterised. Therefore, the influence of O. europaea-derived components present in dry olive leaf extract (DOLE) was examined in two established preclinical models of human T1D, which differ in some aspects of diabetogenesis: multiple low-dose streptozotocin-induced diabetes in susceptible C57BL/6 and CBA/H mouse strains; cyclophosphamide-accelerated diabetes in non-obese diabetic mice. In both T1D models, in vivo administration of DOLE significantly reduced clinical signs of diabetes (hyperglycaemia and body weight loss) and led to complete suppression of histopathological changes in pancreatic islets. In line with these, insulin expression and release were restored in DOLE-treated mice. Interestingly, inducible NO synthase expression and NO production were significantly elevated in peripheral tissues but were down-regulated within the local environment of the endocrine pancreas. This interference was reflected in NO-mediated suppression of T lymphocyte proliferation and lower production of the proinflammatory cytokines interferon-gamma, IL-17 and TNF-alpha in the spleen, with subsequent blockade of beta-cell destruction. The results suggest that DOLE interferes with development of autoimmune diabetes by down-regulating production of proinflammatory and cytotoxic mediators. Therefore, the potential use of a DOLE-enriched diet for prophylaxis/treatment of human T1D, and possibly other autoimmune diseases, is worthy of further investigation.

Standardized Olea europaea L. leaf extract exhibits protective activity in carbon tetrachloride-induced acute liver injury in rats: the insight into potential mechanisms.

The protective activity of dry olive leaf extract (DOLE) in carbon tetrachloride (CCl4)-induced liver damage and possible mechanisms involved in this protection were investigated in rats. Acute CCl4 intoxication resulted in a massive hepatic necrosis, in increased serum transaminases, and in a perturbation of oxidative stress parameters in liver tissue [malondyaldehide, glutathione (GSH), catalase]. CCl4 did not affect the expression of caspase-3 and cytochrome c as markers of apoptosis; however, CCl4 increased the AMP-activated protein kinase (AMPK) activity and the expression of autophagy-related protein LC3II and decreased the expression of p62 protein. The pre-treatment with DOLE significantly improved serum markers of liver damage, liver catalase activity, and GSH concentration, suggesting that antioxidative mechanism is responsible for hepatoprotection. Oral administration of DOLE did not influence LC3II conversion and p62 degradation in liver, but AMPK activity was significantly decreased, suggesting the energy balance perturbation as an additional potential mechanism of DOLE hepatoprotective effect.

Attenuation of cold restraint stress-induced gastric lesions by an olive leaf extract.

Olive leaf extract (OLE) possesses, among other, antioxidative properties, but whether it influences gastroprotection against stress-induced gastric lesions remains unknown. In this study we investigated the protective effect of OLE, a natural antioxidant, on gastric mucosal damage induced by cold restraint stress (CRS) in rats. Three different doses of commercial OLE EFLA((R)) 943 were applied intragastrically (i.g.) 30 min prior to stress induction. Macroscopic gastric lesions were evaluated and ulcer index (UI) was calculated. Histological evidence of gastric mucosal lesions was also obtained. Concentration of malondialdehyde (MDA) as an index of lipid peroxidation, and catalase (CAT) and superoxide dismutase (SOD) activities were determined in gastric mucosa. The effects of applied OLE on gastric mucosal lesions, lipid peroxidation and antioxidative enzymes activity were compared with effects of i.g. pretreatment of reference drug, ranitidine. CRS caused severe gastric lesions in all non-pretreated animals, and this finding was confirmed histologicaly. Pretreatment with OLE (40, 80 and 120 mg.kg(-1)), as well as with ranitidine (50 mg.kg(-1)), significantly (p < 0.001) attenuated stress-induced gastric lesions. Treatment with 80 mg.kg(-1) of OLE was the most effective in prevention of rise in gastric MDA level and decrease in CAT and SOD activity. The results obtained indicate that OLE possesses gastroprotective activity against CRS-induced gastric lesions in rats, possibly related to its antioxidative properties.

Dry olive leaf extract attenuates DNA damage induced by estradiol and diethylstilbestrol in human peripheral blood cells in vitro.

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 17ß-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.

Assessment of adrenaline-induced DNA damage in whole blood cells with the comet assay.

Harmful effects of elevated levels of catecholamines are mediated by various mechanisms, including gene transcription and formation of oxidation products. The aim of this study was to see whether the molecular mechanisms underlying the damaging action of adrenaline on DNA are mediated by reactive oxygen species (ROS). To do that, we exposed human whole blood cells to 10 µmol L-1adrenaline or 50 µmol L-1H2O2(used as positive control) that were separately pre-treated or post-treated with 500 µmol L-1of quercetin, a scavenger of free radicals. Quercetin significantly reduced DNA damage in both pre- and post-treatment protocols, which suggests that adrenaline mainly acts via the production of ROS. This mechanism is also supported by gradual lowering of adrenaline and H2O2-induced DNA damage 15, 30, 45, and 60 min after treatment. Our results clearly show that DNA repair mechanisms are rather effective against ROS-mediated DNA damage induced by adrenaline.

Acute toxicity study in mice of orally administrated TiO2 nanoparticles functionalized with caffeic acid.

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.

Highly potent antioxidant Olea europaea L. leaf extract affects carotid and renal haemodynamics in experimental hypertension: The role of oleuropein.

Haemodynamic alterations in carotid and renal arteries are associated with the severity of target organ damage in patients with hypertension. Dietary habits, such as the Mediterranean diet, regulate blood pressure and oxidative stress, thus reduce the mortality rate due to cardiovascular diseases. In this study, our aim was to evaluate the reducing activity, antioxidant capacity and metal chelating ability of standardized Olea europaea L. leaf extract (OLE), and to test its (5, 25, 50 mg/kg) acute in vivo effects, as well as oleuropein's (OP, 10 mg/kg) on oxidative stress, carotid, renal and systemic haemodynamic parameters (blood pressure, heart rate, cardiac output, peripheral resistance) in spontaneously hypertensive rats (SHR). OLE has a higher antioxidative capacity than BHT, higher reducing ability than vitamin C, and 23 times lower capacity for metal ion chelation than EDTA. All three doses of OLE, and OP, improved oxidative stress in SHR. OLE5 improved carotid and renal haemodynamics, without significant effects on systemic haemodynamics. Two different mechanisms of antihypertensive responses to OLE were observed, OLE25 was most effective in reducing cardiovascular risks by improving systemic and regional (carotid and renal) haemodynamics, peripheral and regional vascular resistance. OLE50 causes the improvement of blood pressure and cardiac performances, but tends to retain elevated vascular resistance, therefore, reducing the inflow of blood into the brain and kidneys of the SHR. The OP did not alter systemic or regional haemodynamics, suggesting others constituents responsible for changes of cardiac function, as well as carotid and renal haemodynamics in response to OLE50.

Manuka honey attenuates oxidative damage induced by H2O2 in human whole blood in vitro.

Manuka honey has been widely researched regarding its biological properties, in particular its antimicrobial and antioxidant capacities. We tested the genotoxic and genoprotective properties of Manuka honey, ranging from 25-1000 µg/mL, by performing an in vitro comet assay after exposure to human whole blood. No genotoxic effect on whole blood cells was observed within the tested concentration range (p = 0.154). Then, the antigenotoxic potency of Manuka honey against oxidative DNA damage to whole blood cells was assessed. Prior to Manuka honey treatment a modest decrease of H2O2-induced DNA damage was detected in cells, with no statistical significance (p = 0.087). Post-treatment, Manuka honey displayed a stronger potential to attenuate damaged cells at all tested concentrations, with a statistical significant difference (p < 0.001), where concentrations of 25 and 100 µg/mL were most efficient. Manuka honey exhibited a marked potential to protect DNA of whole blood cells from oxidative damage induced by hydrogen peroxide in vitro.

Unexpected effect of dry olive leaf extract on the level of DNA damage in lymphocytes of lead intoxicated workers, before and after CaNa2EDTA chelation therapy.

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.