Gokce Nardemir

Molecular determination of genotoxic effects of cobalt and nickel on maize (Zea mays L.) by RAPD and protein analyses

Assessment of DNA damages stemming from toxic chemicals is an important issue in terms of genotoxicology. In this study, maize (Zea mays L.) seedlings were used for screening the genotoxic effects of cobalt (Co) and nickel (Ni) treatments at various concentrations (5 mM, 10 mM, 20 mM and 40 mM). For this purpose, randomly amplified polymorphic DNA (RAPD) technique was applied to genomic DNA extracted from metal-exposed and unexposed plant materials. Besides, changes in total protein contents were screened by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis. For RAPD analysis, 16 RAPD primers were found to produce unique polymorphic band profiles on different concentrations of Co-/Ni-treated maize seedlings. Increased polymorphism resulting from the appearance of new bands or disappearance of normal bands was observed with increasing concentration of Co and Ni treatments. Genomic template stability, a qualitative measurement of changes in RAPD patterns of genomic DNA, decreased with increasing metal concentration. In SDS-PAGE analysis, it was observed that the total soluble protein content decreased by Co treatment, while it increased by Ni treatment. The results obtained from this study revealed that RAPD profiles and total soluble protein levels can be applied to detect genotoxicity, and these analyses can offer useful biomarker assays for the evaluation of genotoxic effects on Co- and Ni-polluted plants.

Determination of genomic instability and DNA methylation effects of Cr on maize (Zea mays L.) using RAPD and CRED-RA analysis

In this research, we aimed to evaluate DNA damage levels, DNA methylation, protein and phytohormone levels changes in corn (Zea mays L.) seedlings exposed to chromium nitrate (Cr). The results showed that the used all chromium doses caused a decreasing mitotic index, genomic template stability and soluble protein levels and increasing in RAPDs profile changes (DNA damage) and DNA hypermethylation. In additional, in the high-pressure liquid chromatography analyses, it was also observed that Cr contamination caused a decreasing in the growth-promoting hormones including gibberellic acid (GA), zeatin (ZA) and indole acetic acid (IAA) levels, in contrast to abscisic acid (ABA) level. The results of this experiment have clearly shown that Cr has epigenetic effect as well as genotoxic effect. Some of phytohormones decreasing (GA, ZA and IAA) and especially increasing of ABA levels under Cr stress may be a part of the defense system against the stress.

Antigenotoxic potencies of a lichen species, Evernia prunastri

In this article, the genotoxic and antigenotoxic effects of methanol extract of Evernia prunastri (Huds.) Willd. (MEP) were studied using WP2, Ames (TA1535 and TA1537) and sister chromatid exchange (SCE) test systems. The results obtained from bacterial test systems demonstrated that MEP has strong antimutagenic potencies on TA1537 and WP2 strains. The highest inhibition rates for MEP on TA1537 and WP2 strains were 37.70% and 69.70%, respectively. According to the SCE test system, MEP reduced the genotoxic effects of aflatoxin. In order to clarify the mechanism underlying the antigenotoxic effects of MEP, the antioxidants were determined. Cotreatments of 5, 10 and 20 µg/mL concentrations of MEP with aflatoxin B1 decreased the frequencies of SCE and the malondialdehyde level and increased amount of superoxide dismutase, glutathione and glutathione peroxidase which were decreased by aflatoxin. The data obtained from this work have clearly shown that MEP has significant antigenotoxic effects which are thought to be partly due to the antioxidant activities and antioxidant inducing capability of MEP. This is the first report indicating the antigenotoxic activities of MEP against several mutagen agents such as N-methyl-N′-nitro-N-nitrosoguanidine, acridin and aflatoxin.

Determination of genotoxic effects of boron and zinc on Zea mays using protein and random amplification of polymorphic DNA analyses

In this research, we aimed to determine genotoxic effects of boron (B) and zinc (Zn) on Zea mays by using total soluble protein content and random amplification of polymorphic DNA (RAPD) analyses. For the RAPD analysis, 16 RAPD primers were found to produce unique polymorphic band profiles on treated maize seedlings. With increased Zn and B concentrations, increased polymorphism rate was observed, while genomic template stability and total soluble protein content decreased. The treatment with Zn was more effective than that of B groups on the levels of total proteins. The obtained results from this study revealed that the total soluble protein levels and RAPD profiles were performed as endpoints of genotoxicity and these analyses can offer useful biomarker assays for the evaluation of genotoxic effects on Zn and B polluted plants.

Anti-Genotoxic and Anti-Oxidant Effects of Origanum rotundifolium on Human Lymphocytes In vitro

Abstract In this study, we aimed to determined the antagonistic effects of Origanum rotundifolium essential oil against the effects ofAflatoxin B 1 (AFB 1) as and inducer of oxidative stress and genotoxic agent in human lymphocytes in vitro. Sister chromatid exchange (SCE) and micronucleus (MN) tests were used for genotoxic influences estimation. In both the test systems, it was observed that O. rotundifolium essential oil suppressed the mutagenic effects of AFB1. Biochemical parameters malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity were examined to determine oxidative stress. This result showed that 5μM concentrations of AFB1 malondialdehyde (MDA) level increased, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities decreased. However these effects of AFB1 seen at higher levels decreased after treatment with 1.0, 1.5 and 2.0 μL/6mL concentrations of O. rotundifolium. The results of this experiment have clearly shown that O. rotundifolium essential oil has strong anti-genotoxic effect against AFB1 and that this capacity could be due to anti-oxidative properties.

Genotoxic, antigenotoxic and antioxidant properties of methanol extracts obtained from Peltigera horizontalis and Peltigera praetextata

Now-a-days, there is a big need to reduce genotoxic effects of mutagenic and carcinogenic agents in environment, which are increased by the technological development. Lichens produce a wide variety of unique metabolites due to being in various extreme areas and being symbiotic organisms of fungi and algae. Therefore, this study was planned to search new sources having antimutagenic activity by researching two different lichen species and to determine whether their usage is safe. With this respect, the mutagenic and antimutagenic properties of methanol extracts of the lichens were determined by the bacterial reverse mutation and sister chromatid exchange assays. Furthermore, the malondialdehyde level, superoxide dismutase, glutathione and glutathione peroxidase activities against aflatoxin B1 were determined for understanding the ways in which the lichens showed their genotoxic properties.

Investigation of Anti-oxidative and Anti-genotoxic Effects of Origanum vulgare L. Essential Oil on Human Lymphocytes In vitro

Abstract Origanum vulgare L. (Lamiaceae) is a flavoring herb widely using around the world. Some preparations and extracts from O. vulgare have been used in Turkish traditional medicine to treat several ailments including digestive disorders and menstrual problems. This study is designed to examine the chemical composition and in vitro antigenotoxic and antioxidant activity of the essential oil of O. vulgare (OVE) from Turkey. The essential oil of O. vulgare was analized by using GC. OVEs that were investigated antagonistic effects against oxidative stress and the genotoxic effects of aflatoksin B1 (AFB1). Anti-genotoxic activity was evaluated by sister chromatid exchanges (SCEs) and micronucleus (MN) tests. In additional to investigating protective role of OVEs against the oxidative stress of AFB1 in vitro, oxidative status was assessed on erythrocytes by measuring following oxidative stress markers like; super oxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA).The total of the 25 identified components are accounted for 96.03 % (GC). Major components of the oil were β-caryophyllene (20.40 %), and caryophyllene oxide (34.44 %). In the SCE and MN tests, it was observed that OVEs suppressed the mutagenic effects of AFB1. OVEs were observed to modulate the adverse effects of AFB1. The results of this experiment clearly reveal that OVEs have strong anti-oxidative and anti-genotoxic effect. These anti-genotoxic effects of O. vulgare essential oils are probably related to its action on the enzymatic activation system. Anti-oxidative and anti-genotoxic effect may be role of these compounds (β-caryophyllene and caryophyllene oxide).

Antagonistic effects of Satureja hortensis essential oil against AFB, on human lymphocytes in vitro

Satureja hortensis L. (Lamiaceae) has been used as a folk remedy to treat various such as cramps, muscle pains, nausea, indigestion, diarrhea, and infectious diseases. In this study, the antagonistic effects of essential oil of S. hortensis (SHE) were studied against aflatoxin B1 (AFB1) in human lymphocytes in vitro. The analysis of the essential oil was performed by using Gas chromatography-mass spectrometry (GC-MS). Anti-genotoxic effects of the SHEs was evaluated using sister chromatid exchange (SCE), micronuclei (MN) tests against AFB1. Also level of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities used to determine the anti-oxidative effects of the SHEs. This result showed AFB1 (5 μM) increased the frequencies of SCE, MN and the level of MDA. AFB1 at the same concentration decreased the activities of SOD and GPx. However, different concentrations of SHE with AFB1 decreased the frequency of SCE and MN and level of MDA and also increased the activities of SOD and GPx significantly. Especially, the 1.0, 1.5, 2.0 μL dose of SHE are more effective than other doses. The results of this experiment have clearly shown that SHE has strong antioxidative and antigenotoxic effects, these biological activities of SHEs can be due to its component.

Cytogenetic and epigenetic alterations by cobalt and nickel on Zea mays L

Changes in DNA methylation in Zea mays plantlets in response to cobalt and nickel (5, 10, 20, and 40 mmol L−1) evaluated by the coupled restriction enzyme digestion-random amplification technique revealed dose-related increases in hypermethylation. The effects on mitotic index and phytohormone levels were also determined. Co and Ni caused a decrease in mitotic index and an attenuation in the growth-promoting hormones gibberellic acid, zeatin, and indole acetic acid, while abscisic acid levels rose. These findings have shown that the increase in abscisic acid levels and DNA methylation depend on the concentrations of Co and Ni.

Protective Role of Mentha longifolia L. ssp. longifolia against Aflatoxin B

Abstract The aim of this study was to investigate the effects of essential oil of Mentha longifolia L. ssp. longifolia, used since ancient times for the treatment of many digestive tract diseases, on the genotoxicity and oxidative stress by a single dose of Aflatoxin B1 (5 µM) in the human lymphocyte culture. The total of the 12 identified components accounted for 97.69 % by Gas chromatography (GC). Major components of the oil were cis-piperitone epoxide (26.52 %), piperitenone oxide (26.40 %), pulegone (15.66 %) and piperitenone (13.57 %). According to the results obtained from GC-MS systems, monoterpenes consist of 89.19 % of the total oil approximately while sesquiterpenes were represented in small quantities in the oil. We studied the anti-genotoxic effects of essential oils of M. longifolia (MEO) by using sister chromatid exchange (SCE) and micronucleus (MN) test systems. Also, the anti-oxidative effects of MEO were evaluated by using superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) assay. The SCE frequency and the number of MN were increased when treated with AFB1. Especially, MEO at 1.5 and 2.0 µl reduced SCE frequency and MN number in the human lymphocyte (p <0.05). In addition, AFB1 treatment significantly reduced the activity of SOD and GPx and elevated the level of MDA (p<0.05). MEOs treatment led to significant attenuation of AFB1-induced oxidative stress by normalization of the activities of SOD and GPx and the MDA (p < 0.05). These results suggest that MEOs could provide anti-oxidative and anti-genotoxic protection for the oxidative and genotoxic agents that cause many diseases including cancer and neurodegenerative disease.