Antigenotoxic Effects of Biochaga and Dihydroquercetin (Taxifolin) on H2O2-Induced DNA Damage in Human Whole Blood Cells

The health benefits of natural products have long been recognized. Consumption of dietary compounds such as supplements provides an alternative source of natural products to those obtained from the diet. There is a growing concern regarding the possible side effects of using different food supplements simultaneously, since their possible interactions are less known. For the first time, we have tested genotoxic and antigenotoxic effects of Biochaga, in combination with dihydroquercetin. No genotoxic effect on whole blood cells was observed within individual treatment of Biochaga (250 μg/mL, 500 μg/mL and 1000 μg/mL) and dihydroquercetin (100 μg/mL, 250 μg/mL and 500 μg/mL), nor in combination. Afterwards, antigenotoxic potency of both supplements against hydrogen peroxide- (H2O2-) induced DNA damage to whole blood cells (WBC) was assessed, using the comet assay. Biochaga and dihydroquercetin displayed a strong potential to attenuate H2O2-induced damage on DNA in cells at all tested concentrations, with a statistical significance (p < 0:05), whereas Biochaga at the dose of 500 μg/mL in combination with dihydroquercetin 500 μg/mL was most prominent. Biochaga in combination with dihydroquercetin is able to protect genomic material from oxidative damage induced by hydrogen peroxide in vitro

Antigenotoxic effect of quercetin on thyroxine-induced DNA damage in human whole blood cells in vitro

The binding of thyroid hormones to specific nuclear receptors in target cells induces synthesis of enzymes associated with redox processes, leading to the formation of reactive oxygen species (ROS), which can cause damage of DNA molecule. Quercetin has already been shown to have protective effect against DNA damage, with its most pronounced feature being scavenging of free radicals. The aim of this study was to evaluate antigenotoxic potential of quercetin against thyroxine-induced DNA damage in human whole blood cells by using the comet assay. For that purpose, cells were exposed to 50 μM thyroxine and separately pre-treated or post treated with 500 μM of quercetin. Results showed that DNA damage was significantly reduced in cells pre-treated with this scavenger of free radicals. Obtained results indicate the ability of thyroxine to be a mediator of DNA damage and that quercetin displayed protective effect against thyroxine-induced genotoxicity.1st Congress of Geneticists in Bosnia and Herzegovina with International Participation Sarajevo, Bosnia and Herzegovina, 02nd-04th October, 2019, Book of abstract

Antigenotoxic and antioxidant potential of medicinal mushrooms (Immune Assist) against DNA damage induced by free radicals-an in vitro study

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 mu g/mL, while in posttreatment it was the concentration of 250 mu g/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 center dot 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

Cytogenetic alterations in rheumatoid arthritis patients treated with methotrexate and dry olive leaf extract

Oxidative stress and inflammation are DNA instability factors for rheumatoid arthritis (RA) patients. The aims of this study were to evaluate cytogenetic alterations in Peripheral Blood Lymphocytes (PBL) in two groups of RA patients: the early and the long-term RA group; and to examine potential of concomitant treatment with Methotrexate (MTX) and Dry olive leaf extract (DOLE) against cytogenetic damage in RA patients after a 3-weeks treatment. A total of 32 RA patients and 10 healthy individuals were included. RA patients were equally divided into four groups: two groups with early phase RA (one treated with MTX alone, the other in combination with DOLE); and two long-term phase RA groups (group with active disease and group with low disease activity)-both treated with MTX and DOLE combination. PBL cultures were screened for chromosome aberrations and micronuclei frequencies. Significantly increased frequencies of micronuclei were shown in active phase RA disease (both early and long-term) but not in the group with low disease activity, as compared to controls. Chromosome aberrations were detected for all 4 RA groups. The highest frequencies of micronuclei and chromosome aberrations were found in the long-term active RA group. After 3 weeks-treatment, there were no significant decrease of the micronuclei frequencies compared to baseline, although they were reduced in all RA groups, except for the group with the long-term active disease. High level of cytogenetic damage in RA patients was concordant with duration and activity of the RA disease. At 3 weeks of therapy, neither the combined treatment (MTX+DOLE), nor MTX alone did not affect the frequency of micronuclei formation

Assessment of DNA damage in blood, liver and kidney cells in a hypertensive rat model using comet assay

Hypertension is one of the primary risk factors for heart disease and stroke, the leading causes of death worldwide. Numerous factors have been implicated in the pathophysiology of hypertension: endothelial dysfunction, arterial remodeling and vascular inflammation. Common to all these processes is increased bioavailability of reactive oxygen species in the vessels, heart, brain and kidneys. Oxidative stress and increased reactive oxygen species levels damage all macromolecules, with DNA being particularly susceptible to oxidative damage. The aim of this study was to determine whether there is a difference in the level of DNA damage between normotensive and hypertensive rats using the alkaline comet assay. Blood samples and cells suspension from liver and kidney from three male spontaneously hypertensive rats were obtained. Three normotensive male Wistar rats were used as a control. Increased level of DNA damage was detected in blood and both of the studied tissues of hypertensive rats compared to the control, where significant difference was present in the liver and kidney cell suspensions. These results indicate that untreated hypertension in rats leads to an increased DNA damage in all of the studied samples, detected by comet assay.1st Congress of Geneticists in Bosnia and Herzegovina with International Participation Sarajevo, Bosnia and Herzegovina, 02nd-04th October, 2019, Book of abstract

Evaluation of repair kinetics of oxidative damaged DNA in peripheral blood leukocytes treated with chaga mushroom (Inonotus obliquus) extract in vitro

Inonotus obliquus, edible medicinal mushroom found in northern hemisphere, is widely used for the prevention and treatment of cancer, diabetes, colitis and asthma. Its bioactives, triterpens, polysaccharides and polyphenols exhibit antitumor, anti-inflamatory, hypoglycemic, immunomodulatory effects, as well as antioxidative properties. Oxidative stress and increased ROS levels lead to tissue damage, with DNA molecule being particularly susceptible to oxidative damage. ...ICAW 201

The large plasmidome of Lactococcus lactis subsp. lactis bv. diacetylactis S50 confers its biotechnological properties

Plasmids are autonomous episomally replicating genetic elements, which carry backbone genes important for the replication and maintenance within their host, and accessory genes that might confer an advantage to their host under specific selective pressure in its ecological niche. The genome of dairy isolate L. lactis subsp. lactis bv. diacetylactis S50 was sequenced using the PacBio SMRT Cell Seq-RSII platform and revealed to possess one of the largest plasmidomes among L. lactis strains studied so far, harboring six plasmids: pS6 (5553 bp), pS7a (7308 bp), pS7b (7266 bp), pS19 (19,027 bp), pS74 (74,256 bp) and pS127 (127,002 bp) in total representing 8.9% of genome size (240,412 bp). Based on predicted plasmid replication proteins and origins it appears that all six plasmids replicate via the theta-type mechanism. The two the largest plasmids (pS74 and pS127), carry a number of genes known to be important for growth and survival in the dairy environment. These genes encode technological functions such as bacteriocin production, protein degradation, magnesium and cobalt/nickel transporters, selenium binding, exopolysaccharides (EPS) production, bacteriophage and stress resistance. Beside genes for replication, the small plasmids (pS6, pS7a, pS7a, and pS19) also carry genes important for mobilization and host survival such as type I restriction-modification (R-M) system, metal transporters, enzymes and transcriptional regulators. All plasmids in S50 strain are mobilizable, containing an oriT sequences, while pS127 is self-conjugative and allows for mobilization of the other plasmids. Small plasmids are prone to structural and segregational instability, while pS127 appeared to be segregationally stable thanks to the possession of two partition systems. The main characteristic of plasmid pS74 is EPS production, while plasmid pS127 is characterized by proteinase and multiple bacteriocins, tra locus, phage abortive systems and metal transporters. In addition to LcnA and LcnB, plasmid pS127 encodes several bacteriocin-pheromone molecules and a new bacteriocin named LcnS50, with narrow spectrum of action limited to lactococci, that has been successfully cloned and heterologously expressed

Antioxidative and anti-inflammatory effects of taxifolin in H2O2-induced oxidative stress in HTR-8/SVneo trophoblast cell line

Oxidative stress has been implicated in numerous pregnancy-related disorders. Biologically active plant secondary metabolites, which are present in everyday diet, could prove effective therapeutic agents in preventing these disorders. This study evaluated effects of taxifolin (dihydroquercetin) on ROS production, markers of oxidative damage to lipids and proteins, activity of antioxidant enzymes and production of pro-inflammatory cytokines in H2O2-induced oxidative stress in trophoblast HTR-8/SVneo cells. Taxifolin in 10 µM and 100 µM concentrations attenuated oxidative damage to lipids and proteins, as evidenced by a decrease in MDA content, extracellular LDH activity, carbonyl groups and nitrite contents. A reduction in the activity of antioxidant enzymes SOD, CAT and GPx in cells pre-treated with taxifolin, prior to H2O2 exposure, was also observed, along with a reduction in intracellular ROS production. Both evaluated concentrations of taxifolin showed antiinflammatory activity in trophoblast cells, by reducing production of pro-inflammatory cytokines IL-1β and IL6. In this model of H2O2-induced oxidative stress, taxifolin showed marked antioxidative and antiinflammatory activities in trophoblast cells, adding further evidence of its protective effects and showing potential as a therapeutic agent in preventing adverse pregnancy outcomes

DNA, protein and lipid oxidative damage in tissues of spontaneously hypertensive versus normotensive rats

Oxidative damage to protein and lipid macromolecules in target organs in hypertension has been recognized as a major factor contributing to cardiovascular, cerebrovascular, and renal diseases. Data on protein and lipid oxidative damage in spontaneously hypertensive rats are numerous, but there is no information on DNA damage in tissues measured by comet assay. The aim of this study was to determine the baseline damage to DNA, protein, and lipid macromolecules in different organs of spontaneously hypertensive rats. Markers of lipid peroxidation, protein oxidation, and DNA damage were measured in blood, heart, kidney, and liver of 24-week-old spontaneously hypertensive rats. Plasma prooxidant and antioxidant status were determined as well. Age-matched normotensive Wistar rats were used as control. A rise in markers of lipid peroxidation and protein oxidation, malondialdehyde, and advanced oxidation protein products, was detected in all tissues of spontaneously hypertensive rats, with particularly high values in the liver. DNA damage, measured by the comet assay, was significantly higher in all the studied tissues of spontaneously hypertensive rats compared to normotensive control, with more severe damage in the cardiac and renal cells. Significant depletion of the plasma antioxidant barrier in spontaneously hypertensive rats was also observed. This study showed increased damage to all macromolecules in all studied samples of spontaneously hypertensive rats in comparison with control Wistar rats