Mitotic Depression Research Articles

Cytotoxic and Mitodepressive Effect of Insecticide Profenofos on Root Meristem of Allium cepa L.

A study was performed for cytotoxic and mitodepressive effect of pesticide through root meristem of Allium cepa L. Various concentration (0.2%, 0.4%, 0.6%, 0.8% and 1.0%) of organophosphate insecticide profenofos for 24, 48 and 72 hrs time points exposed to A. cepa. The cytotoxic and genotoxic effects were evident through inhibited mitotic division and increased percentage of chromosome abnormality. Dose and duration dependent statistically significant reduction in mitotic index was recorded. The minimum mitotic index (3.94%) was estimated at 1.0% for 72 hrs. Cytogenetic endpoints like mitotic depression, relative abnormality rate and frequency of chromosomal abnormality were found to be increased when compared to control plants. Various chromosomal aberration like stickiness, laggard, bridge, fragmentation and micronuclei were also observed. Cytogenetic biomarker is very efficient and non-expensive tool to screening and biomonitoring cytotoxicity at chromosomal and DNA level.

Phytotoxicity of trihalomethanes and trichloroacetic acid on Vigna radiata and Allium cepa plant models.

Disinfection by-products (DBPs) are a concern due to their presence in chlorinated wastewater, sewage treatment plant discharge, and surface water, and their potential for environmental toxicity. Despite some attention to their ecotoxicity, little is known about the phytotoxicity of DBPs. This study aimed to evaluate the individual and combined phytotoxicity of four trihalomethanes (THMs: trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and tribromomethane (TBM) and their mixture (THM4)), and trichloroacetic acid (TCAA) using genotoxic and cytotoxic assays. The analysis included seed germinationtests using Vigna radiata and root growthtests, mitosis studies, oxidative stress response, chromosomal aberrations (CA), and DNA laddering using Allium cepa. The results showed a progressive increase in root growth inhibition for both plant species as the concentration of DBPs increased. High concentrations of mixtures of four THMs resulted in significant (p < 0.05) antagonistic interactions. The effective concentration (EC50) value for V. radiata was 5655, 3145, 2690, 1465, 3570, and 725 mg/L for TCM, BDCM, DBCM, TBM, THM4, and TCAA, respectively. For A. cepa, the EC50 for the same contaminants was 700, 400, 350, 250, 450, and 105 mg/L, respectively. DBP cytotoxicity was observed through CAs, including C-metaphase, unseparated anaphase, lagging chromosome, sticky metaphase, and bridging. Mitotic depression (MD) increased with dose, reaching up to 54.4% for TCAA (50-500 mg/L). The electrophoresis assay showed DNA fragmentation and shearing, suggesting genotoxicity for some DBPs. The order of phytotoxicity for the tested DBPs was TCAA > TBM > DBCM > BDCM > THM4 > TCM. These findings underscore the need for further research on the phytotoxicity of DBPs, especially given their common use in agricultural practices such as irrigation and the use of sludge as manure.

Cytological Effects of Two Varieties of Lathyrus Sativus L. Extracts on Onion Root Tip Cells

Lathyrus sativus L. causes lathyrism both in animals and human due to the presence of the neurotoxin β-ODAP (β -N-Oxalyl-L-α, β -diaminopropionic acid). This study was performed to find out the toxic effect of grass pea on onion root tip cells. The root lengths of onion were reduced as the concentrations of different plant parts extracts of grass pea increased. The percentages of chromosomal abnormalities, NV and ICV of onion root tip cells showed an increasing trend with the increasing of different extracts concentrations. The mitotic index and chromosomal abnormalities in treated onion root tip cells were significantly different than that of control. The mitotic index and chromosomal abnormalities had a reverse relationship. Almost all the treated root tip cells of onion showed this mito-depressive effect. From this findings, it may concluded that β -N-Oxayl-L- α, β-diaminopropionic acid (Lathyrogens) in Lathyrus sativus may be responsible for mitotic depression and chromosomal abnormalities on the root tip cells of onion. J. Bio-Sci. 31(1): 51-60, 2023

Application of Pteris vittata L. for phytoremediation of arsenic and biomonitoring of the process through cyto-genetic biomarkers of Trigonella foenum-graecum L.

The arsenic (As) contamination demands its remediation from the environment which is naturally possible by the application of Pteris vittata L. However, biomonitoring of phytoremediation potential of P. vittata at chromosomal and DNA level is still meager. The present study was designed to biomonitor the phytoremediation efficiency of P. vittata through phytotoxic and cyto-genotoxic biomarkers assessment using Trigonella foenum-graecum L. (Fenugreek; Methi) as test system. Study revealed hyperaccumulation potential of P. vittata which extracted arsenic in its tissues. Biomonitoring evaluation depicted that phytotoxic damage was reduced in Trigonella exposed to remediated soil, which was revealed through reduced electrolyte leakage, hydrogen peroxide and MDA content. Moreover, cyto-genetic endpoints like mitotic depression (44.03%), relative abnormality rate (16.6%) and chromosomal abnormality frequency (1.06%) were also lesser in test plants grown in remediated soil compared to those grown in non-remediated soil. Along with this various chromosomal aberrations like stickiness, breaks, laggards, bridges, fragmentations and micronuclei were also augmented in test plants exposed to non-remediated arsenic enriched soil. It was evident that arsenic enriched soil caused toxicity to plants in dose-dependent manner that was assessable through the analysis of biochemical parameters and cyto-genetic biomarkers. The cyto-genetic biomarkers are very efficient, simple and non-expensive tools to biomonitor arsenic toxicity at chromosomal as well as DNA level to assess the remediation potential of P. vittata in field conditions.

Evaluation of Phytoremediation Potential of Pteris vittata L. on Arsenic Contaminated Soil Using Allium cepaBioassay.

The present study assessed the utility of Allium cepa based cyto-genotoxicity bioassays in evaluating the arsenic toxicity and remediation potential of Pteris vittata on contaminated soil of Lakhimpur-Kheri district. Untreated and P. vittata treated soil extracts were used for cyto-genotoxicity tests in A. cepa. Results showed that P. vittata extracted high concentration of arsenic, which ranged from 220 to 1420 mgkg-1 in different soils. Cyto-genotoxic assessment of A. cepa showed that extract of P. vittata treated soil had lower cyto-genotoxic effects as compared to untreated soil. A higher mitotic index (10%) while lower mitotic depression (29%), relative abnormality rate (10%), chromosomal aberrations (1%) and micronuclei (2%) were detected in root meristematic cells of A. cepa exposed to remediated soil extract in comparison to untreated soil. The studies provide a simple, rapid and economic cyto-genotoxicity bioassay tool for evaluating toxicity of contaminated soils of contaminated soils as well as revealed the phytoremdiation property of P. vittata against arsenic toxicity.

Митоинхибиращ и кластогенен ефект на води от антропогенно повлияни зони

The present study aims to analyse the effect of waters, anthropogenically influenced by various pollutants, on the mitotic division and chromosomal apparatus of cells by establishing their potential mitoinhibitory and clastogenic effect. The cytotoxic and mutagenic effect of contaminated water was examined by the application of the Allium cepa test system. Mitotic depression has been established for samples with available anthropogenic contamination. Microscopic analysis showed an increased incidence of chromosomal aberrations in the test samples compared to the control, resulting from the genotoxic effect available. Chromosomal abnormalities of the type of lagging and ‘vagrant’ chromosomes, chromosomal fragments, anaphase and telophase bridges, micronuclei, as well as deviations from normal cell division such as K-mitoses and asynchronous mitoses have been observed. The analysis of the spectrum of chromosomal aberrations shows some differences in the frequency of occurrence of the different types of disorders, which reflects the specificity of the genotoxic effect of the water samples from the surveyed areas.

Phyto-genotoxicity of arsenic contaminated soil from Lakhimpur Kheri, India on Vicia faba L.

The present experiment was designed to evaluate physico-chemical characteristics and phyto-genotoxicity of arsenic (As) contaminated soil collected from different sites of Lakhimpur, Uttar Pradesh (UP), India by employing Vicia faba L. The analyses included various biochemical as well as cyto-genotoxicity assays. The results showed that soil pH was slightly acidic to neutral in nature. The bulk density (1.18-1.23 gcm-3), particle density (2.51-2.59 gcm-3) and porosity (44-53%) varied in different places. The level of available nutrients, nitrogen, phosphorus and potassium was found to vary as 124-165 mgkg-1, 173-186 mgkg-1 and 48-98 mgkg-1, respectively. The maximum As levels were found in soil of Fulvareya (27.13 mgkg-1) and Atareya (24.12 mgkg-1), the level of As in water samples of these sites were 0.19 mgl-1and 0.21 mgl-1, respectively. Phytotoxicity of the As present in soils was evident through significant increases in stress metabolites, hydrogen peroxide (H2O2), malondialdehyde (MDA) and carbonyl groups in root and shoot of V.faba. Cyto-genotoxic effects were also seen through reduced mitotic index (MI) and increased mitotic depression (MD), relative abnormality rate (RAR) as well as other chromosomal abnormalities along with micronuclei in root meristematic cells of V.faba. The phytotoxicity and cyto-genotoxicity assessment suggests the harmful soil properties that might affect biota.

Cadmium toxicity and its relationship with disturbances in the cytoskeleton, cell cycle and chromosome stability.

This study aimed to investigate the mode of action of cadmium (Cd) toxicity at cell level, especially at early stages of plant exposure. Tomato seedlings were cultivated in growth media containing from 0.1 to 70 µM CdCl2 for 24 h. Mitotic index, chromosome abnormality, DNA integrity and organization of tubulin-based structures were assessed in root cells. As higher the Cd concentration in the growth media, higher was the DNA damage intensity and the occurrence of chromosomal abnormalities that included chromosome lost, bridges, stickiness, C-metaphase and polyploidy. The profile of chromosomal aberrations also varied with elevated Cd concentration, being observed increases in the frequency of chromosome stickiness. The mitotic index was reduced at the lowest Cd concentration, but such reduction was statistically similar to that detected at the highest concentration, suggesting that mitotic depression is a rapid outcome and, at same time, a Cd-induced effect that is limited at the first 24 h of direct root exposure to this metal. Under exposure to 20 µM CdCl2, heterogenous distribution of the spindle fibers, formation of two spindle complexes in both of the cell poles, absence of centrosome center, polarization of the spindle fibers during cell division, and non-uniform tubulin deposition in microtubule and phragmoplast were noticed. The results indicate that the tubulin-dependent components of cytoskeleton are Cd targets, and the sensitivity of tubulin-based structures to Cd exposure depends on cell cycle phase. Moreover, DNA damage intensity and chromosomal abnormality profile can be employed as markers of Cd toxicity level.

Toxic and mutagenic activities of surface water from the Chumysh River

&lt;p&gt;The Allium test system is worldwide used for biological monitoring of environmental pollutants. We have studied toxic and mutagenic activity of water from the Chumysh River, which is one of the largest tributaries of the Upper Ob. Water samples were taken near industrial settlement Talmenka (Altai Territory of Russia) during the spring flood and low autumn water level in 2015. Root tips of &lt;em&gt;Allium cepa&lt;/em&gt; L. was used as a biological model. There were examined 30 samples. Purified tap water of medium hardness served as a control sample. After the synchronizing the cell divisions, the onion bulbs with roots reaching a length of 2-3 mm were transferred to glass cups containing the selected samples of River water and cultured for several days at a temperature of +24 ± 1°C. After exposure, root tips were rinsed in distilled water and fixed in a cold mixture of ethanol and acetic acid (3:1). Fixed samples were used after 12-24 h or transferred to 70% alcohol and stored in refrigerator at a temperature of +4°C until required. The fixed materials were hydrolyzed in 1N HCl at 60°C for 5-8 min and squashed in aceto-orcein.&lt;strong&gt; &lt;/strong&gt;Prepared slides were viewed under the microscope at a magnification of ×90.&lt;strong&gt; &lt;/strong&gt;The mitotic index (MI), the phase indices, the frequency of abnormal mitosis, and chromosomal aberrations were determined by the examination of 500 cells per a replicate (100 cells per slide). We established that the decreased or increased levels of mitotic activity and the frequencies of pathological mitoses (up to 7.9%, P &amp;lt; 0.05) in onion root tips revealed the presence of mitotoxic and genotoxic agents in the Chumysh River water. We found that the most number of chromosomal abnormalities occurs at the stages of meta- or anaphase. The main abnormalities are chromosome laggings in meta- and anaphase, chromosome bridges, chromosome fragments and micronuclei. Their number increased in 5.0-10.8 times compared with the control value. It has been discovered the temporal and spatial distribution of compounds with different toxicity and genotoxicity within a stream. The greatest level of mitotic depression and the highest frequency of chromosomal mutations were observed in the tissues of the onion root tips germinated on the samples collected in low autumn water. The mechanisms of plant adaptation to unfavorable environmental factors are discussed.&lt;/p&gt;

Influence of 1-p-D-arabinofuranosylcytosine on mitotic activity of apical meristem of onion (Allium cepa L.) roots

The influence of increasing cytosine arabinoside (ara-C) concentration (50, 100, 300 and 500 μg/ml) on the mitotic activity of the apical meristem of onion adventitious roots was investigated during 24-h incubation in ara-C and postincubation in water. Incubation in ara-C inhibits reversibly mitosis, the degree of inhibition being dependent on the concentration used. 50 μg/ml ara-C causes only a slight and transitional mitotic depression, while 100—500 μg/ml reduces the per cent of mitoses in various degrees after 12-h incubation whereas after 24 h all concentrations (100—500) reduce mitosis to the same level of about 2 per cent (80% inhibition). During postincubation in water there occurs after treatment with 100—500 μg/ml ara-C, a wave of highly synchronized mitoses with a peak after 12 h. The highest frequency of synchronized mitoses (60°/o) appeared in roots treated with 300 μg/ml ara-C. The main wave is preceded by a small one with a peak after 2-4 h of postincubation. This seems to be the consequence of phases S and G&lt;sub&gt;2&lt;/sub&gt; inhibition by ara-C. It was found that under the influence of ara-C the per cent of mitoses with chromosome aberration and of cells with micronuclei increased only slightly.

English

&nbsp; The present study reports the potential genotoxic effects of a widely used insecticide, endosulfan (Endoin 35% EC), on root tip cells of onion&nbsp;(Allium cepa L.). Treatment of onion root tips at a concentration of 0.156 &mu;g/L of endosulfan showed highest fluctuation of mitotic depression at various durations (0.38 to -181%) of exposure. The mitotic index decreased with the increase in the concentrations of endosulfan mostly at 48 h treatment. The maximum number of dividing cells (n) was observed to be 224 calculated as maximum MI value of 7.0 in lowest concentration (0.0078 &mu;g/L) at 72 h. The abnormalities of common occurrence were unequal cytokinesis and karyokinesis and formation of binucleolated cells in many cases. Gradual decondensation or little condensed chromosomal arms were the common observations in abnormal metaphases and anaphases. The frequencies of all the mitotic abnormalities showed a good correlation with the concentration of the insecticide. &nbsp; Key words:&nbsp;Allium cepa, endosulfan, mitotic index, aberrant cells, genotoxicity.

Genotoxicity of ibuprofen in mouse bone marrow cells in vivo

Genotoxicity of ibuprofen was evaluated by employing the mouse in vivo chromosomal aberration (CA) test. Ibuprofen administered orally at doses of 10, 20, 40, and 60 mg/kg body weight to mice resulted in mitotic depression and induction of CAs. A dose-related decrease in mitotic index (MI) and an increase in the frequencies of chromosomal aberrations per cell (CAs/cell) were recorded in bone marrow cells. However, a statistically significant reduction in MI and an increase in CAs/cell were found for both the higher doses. The results obtained indicate that ibuprofen is capable of inducing dose-dependent genotoxicity in bone marrow cells of mice.

Effect of triazophos on mitotic activity and chromosomal behavior in root meristems of &lt;i&gt;Allium cepa&lt;/i&gt; L.

Effect of triazophos (an organophosphorous insecticide) on mitotic activity and chromosomal behavior in the meristematic region of root tip cells of Allium cepa L. was assessed. The insecticide showed mitotic depression and positive chromo-toxic effects. Abnormalities, such as stickiness, plasmolysed cells, equatorial plate shifting, polar shifting, irregular chromosome arrangement, precocious arms formation, bridge formation, C-metaphase, fragmentation of chromosomes, unequal cytokinesis, diagonal cytokinesis, delayed cytokinesis and formation of binucleated cells, were recorded in the chemically pretreated root meristem. Key-words: chromosomal and cellular abnormalities; cytotoxic effect; mitotic index; phase indices.DOI: 10.3126/botor.v6i0.2903 Botanica Orientalis - Journal of Plant Science (2009) 6: 4-7

The impairments of neoblast division in regenerating planarian Polycelis felina (Daly.) caused by in vitro treatment with cadmium sulfate

The effects of cadmium sulfate on the neoblast mitotic activity in regenerating planarian Polycelis felina (Daly.) were investigated. Mitotic abnormalities and chromosomal aberrations were evaluated after 6-h treatment and 24-h recovery period. The blastema were fixed, and examined cytologically through routine lactoorceine squash preparations. Mitotic indices were also determined. Cadmium sulfate induced a dose-dependent decrease in neoblast mitotic activity, accompanied with disturbances in distribution of cells over mitotic phases. Different cytological abnormalities with varying frequency were observed. Marked mitotic depression was concentration-dependent. Toxic effects of cadmium in regenerating planarian were mainly associated with mitotic spindle disturbances. Immediately after treatment mitotic abnormalities were prevalent over chromosomal and C-mitosis was the most prominent one. After 24-h recovery period a prevalence of mitotic over chromosomal aberrations was still present in animals treated with two higher concentrations of cadmium sulfate. However, the proportions of cells with chromosome stickiness in all treated animals were significantly increased compared to their post-treatment values. Observed mitotic impairments could be related to mitotic arrest contributing to retardations and delays, especially in animals treated with the highest concentration tested. The results obtained indicated usefulness of short term invertebrate assays as an alternative to in vitro pre-screening of toxic chemicals.

Clastogenicity of carbazole in mouse bone marrow cells in vivo

Clastogenicity of carbazole was evaluated by employing mouse in vivo chromosomal aberration (CA) test. Carbazole administered intraperitoneally (i.p.) at the rate of 25, 50, 100, 150 and 200 mg/kg b.w. to Swiss albino mice in vivo resulted in mitotic depression and induction of chromosomal aberrations. Dose related decrease in mitotic index (MI) and increase in the frequencies of chromosomal aberrations per cell (CAs/cell) and percent abnormal cells were recorded in bone marrow cells. However, statistically significant reduction in MI and increase in CAs/cell and percent abnormal cells were found only for the two higher doses. The results obtained indicate that carbazole or its metabolite, if any, is moderately clastogenic in the bone marrow cells of Swiss albino mice.

A time-course study on effects of aluminium on mitotic cell division in Allium sativum

Cytotoxic effects of aluminium sulphate on root-tip cells of Allium sativum during a time-course study and during recovery were observed. The endpoints considered were mitotic index and frequencies of aberrant cells and micronuclei induced. Chronic exposure induced mitotic depression and abnormal cells to a degree directly proportional to the concentration used and the period of treatment up to 24 h. A reduction of the early higher level of toxicity was noticed following 48 h of treatment and subsequent recovery in aluminium-free nutrient media in experiments carried out with lower concentrations.

Glucocorticoid receptor-mediated teratogenesis and cell proliferation in the limbs and face of the chick embryo.

The susceptibility of the face region of the chick embryo to the teratogenic action of intraamniotically injected hydrocortisone contrasts with the resistance of the limbs to its action while at the same time their dysmorphogenesis may be induced by other agents. Since glucocorticoid receptors were shown to mediate face teratogenesis, their development was investigated in freshly dissected limb buds of 3-, 3.5-, and 4-day-old chick embryos in comparison with the face region. The specific binding of 3H-dexamethasone to molybdate-stabilized glucocorticoid receptors was estimated by the dextran-coated charcoal method and complemented by cytologic analysis of mitotic activity in control and hydrocortisone-treated embryos. The glucocorticoid receptors were found in both organ anlagen already on day 3 when their concentration in femtomoles per microgram DNA was significantly higher in the face region. Accordingly, on day 3 intraamniotic hydrocortisone inhibited the mitotic activity in the face without affecting the developing limbs. On days 3.5 and 4 the concentration of glucocorticoid receptors was similar in both organ anlagen. Administration of hydrocortisone on day 4 induced mitotic depression in the face as well as in the limbs. However, the degree of inhibition appeared to be dependent upon the actual mitotic rate. In the face region where the mitotic activity culminated at that time, the inhibition was much deeper and longer-lasting than in the developing limbs characterized by continuous decrease of proliferation rate in controls. These findings are consistent with a view that glucocorticoid receptors are a prerequisite, but not the only factor in receptor-mediated teratogenesis.

Anaphase-telophase analysis of chromosomal damage induced by chemicals.

Three main aspects involved in the chemical induction of anaphase-telophase aberrations in the first mitosis after treatment were analyzed: 1) the relationship between the frequency of anaphase-telophase aberrations and the time of fixation after treatment; 2) the dose-response relationships; and 3) the proliferative rate of cells exposed to chemicals which interact with DNA by different mechanisms. Experiments were carried out using Chinese hamster ovary (CHO) cells. The compounds examined were adriamycin (ADR) and mitomycin C (MMC). The frequency of cells with chromatin bridges or with lagging chromosomes as well as the mitotic index was determined in each experiment. The results obtained showed that 1) chromatin bridges and lagging chromosomes are apparently induced during the S period of the previous interphase; 2) the increase in the cytotoxicity index (inferred from the mitotic index) and the frequency of cells with chromatin bridges and lagging chromosomes were proportional to the treatment lapse and to the dose employed; and 3) the effect of ADR on cell growth differs from the effect of MMC. While ADR decreased the mitotic activity of cells in logarithmic growth phase, MMC induced mitotic delay. In accordance with these results, the occurrence of chromatin bridges in anaphase-telophase could be explained by the induction of chromosome stickiness and, to a lesser extent, by the induction of exchange-type aberrations. On the other hand, lagging chromosomes seem to be the result of chromatid or chromosome breaks because the lagging chromosomes observed were primarily, if not all, fragments and not whole chromosomes. Our evaluation of the anaphase-telophase test indicates that it is very sensitive method for the detection of chemical clastogens, but other factors, such as mitotic depression, must be taken into account to avoid false-negative results.

Cytokinetic and cytogenetic effect of agricultural chemicals on human lymphoid cells in vitro. II. Organochlorine pesticides.

Human lymphoid cells of LAZ-007 cell line, incubated with 10(-4) to 10(-6) molar of eight different organochlorine pesticides had dose related cytotoxicity, mitotic depression and cell cycle traverse inhibition. In cultures incubated with 10(-4) M concentrations, M1 metaphases were as high as 13% (Dicofol) as compared to less than 1% in the controls. The frequency of M3 metaphases in cultures incubated with 10(-6) M concentrations ranged from 11% (Chlordane) to 15% (Endosulfan) compared to 17% in control cultures. Statistically significant increase in SCE frequency was seen in cells exposed to Chlordane, Dicofol, Endosulfan and Toxaphene. On metabolic activation with rat liver microsomal S-9 enzymes, Chlordane, Dicofol and Tetradifon induced SCE frequency was higher than that of nonactivated cultures.

Cytokinetic behavior of Ehrlich ascites tumor after in vivo treatment with cis-diamminedichloroplatinum(II) and metallocene dichlorides.

The influence of an in vivo treatment with optimally tumor-inhibiting doses of cis-diamminedichloroplatinum(II) (DDP), titanocene dichloride (TDC), and vanadocene dichloride (VDC) on the DNA distribution pattern, determined by pulse-cytophotometry, and on the mitotic activity of EAT cells is investigated. Whereas DDP causes an immediate and long-lasting decrease of mitoses but no disturbances of the EAT cell kinetics, a marked G2 block with a maximum at 10-12 h a. t. and an irreversible and extensive mitotic depression is evoked by TDC. In the case of DDP and TDC, the tumor cells are removed several days a. t. by cells belonging to the defensive system of the host animals. In contrast, VDC induces partially synchronized waves after a transient suppression of mitoses and reversible cell accumulation in the late S and in the G2 phases. Additionally, 5-16% of the cells become polyploid after VDC treatment.