Assessment of genotoxicity of some common food preservatives using Allium cepa L. as a test plant

Food preservatives are unswervingly being used for prolonging the shelf life of food, often to increase the aroma, taste and quality by food packaging industry. These food preservatives are pivotal in protecting food from degradation and deterioration by micro-organisms. Two of the most commonly used food preservatives, viz. sodium nitrite (NaNO2) and Monosodium glutamate (MSG) have been evaluated using root tips of Allium cepa. Cytological studies in plants offer a first-tier bioassay that are sensitive and reliable. Allium cepa is used as an experimental model as it shows chromosomal aberrations and other morphological abnormalities as that of the mammalian systems. Dose and time dependent evaluation of the mitotic damage was done on the root tips of onion (Allium cepa). Mitotic Index (MI) was calculated based on the cytological observation post-treatment with their respected controls. Chromosomal abnormalities like chromosomal bridge and laggard, multipolarity and stickiness in the chromosome was observed in the treated sample.

The purpose of this investigation was to see if Calcium Carbide (CaC2) had any harmful effects on onions (Allium cepa L.). Allium cepa root tips were grown in various concentrations of Calcium Carbide (CaC2) (0.25g, 0.50g, 0.75g, and 1.00g)/ 250ml, with distilled water serving as a control. For cytological tests, the root tips of Allium cepa growing in the treatments and control were removed daily between 7:30am and 8:30am. Pretreatment, fixation, hydrolysis, squashing, and staining of cells for mitotic investigations were performed, and data on cytological parameters were collected using a light microscope at a magnification of X40. The mitotic index (MI) and karyotype analysis were used to assess the data collected on these parameters. The results of this study showed that root tips treated with 0.25g of Calcium Carbide (CaC2) have a mitotic index of 45.83 and the rate of cell division decreases with an increase in the concentration of Calcium Carbide (CaC2) as the cell divides the mitotic index dropped sharply. These finding indicated that Calcium Carbide is a strong mitotic inhibitor and could give rise to mitotic abnormalities with increase in concentration and also reduced cell division. We therefore recommended that there is need for further investigation using lower concentrations of Calcium Carbide as well as other mutagenic substances in order to ascertain their effect on the chromosomal behavior.

The effects of the food preservatives potassium metabisulphite (PMB) and potassium nitrate (PN) have been studied on root tips of Allium cepa L. (variety Kantartopu-3). Roots of A.cepa were treated with a series of concentrations, ranging from 50 ppm to 100,000 ppm for 3, 6, 12, 24 and 48 h. Examinations of roots were done in permanent root tip squash preparations stained by the Feulgen technique. PMB and PN effect on the relative duration of each mitotic stage as compared with the control. They are also caused reduction in the mitotic index, indicating mitotic inhibition and increased frequency of abnormal mitosis.The type of abnormalities induced are chromosome stickiness, c-metaphase, anaphase and telophase bridges, disturbed chromosomes of anaphase and telophase stages, anaphase lagging and forward chromosomes at anaphase and telophase and micronuclei formation at intephase cells.

The purpose of the experiment was to investigate onion (Allium cepa) root growth, cell division, and mitotic index. The onions were placed into four different water samples (Control water, Azadi bridge, Sar Razan, and Sar Baskan) for 72 hours in beakers. The results showed that the number of divided cells decreased significantly in the sewage water compared with the control water. The control water had a high percentage of divided cells (18%), whereas the Sar Razan sewage water had the least percentage of divided cells (1.3%). The percentage of divided cells in Sar Baskan sewage water was 2%, and the percentage of divided cells in Azadi Bridge was 2.6%. It was found that the mitotic index and the number of divided cells increased in the control water compared to the sewage water. The results showed that sewage water has a greater impact on root growth, cell division, and mitotic index of root tips of Allium cepa.

Negative physiological and biochemical effects of chronic and subchronic doses of benzoates and sorbates may pose a certain risk to human health. Identifying new biomarkers responsible for the body’s response to these compounds could provide significant details in determining the mechanism of their toxicity. To assess comparatively physiological, cytological, cytogenetic, and biochemical parameters in onion roots cells we used an Allium test. The roots were previously treated with sorbic and benzoic acids. The study recorded the dose-dependent toxic effect of these preservatives on the root mass growth. The EC50 values obtained for benzoic and sorbic acids (10 mg/L and 110 mg/L respectively) were significantly lower than the regulated concentrations prescribed by the standards for their content in certain types of food products. With an increase in concentrations of these acids, the mitotic index of meristematic cells decreased in experimental groups compared to control groups. The data obtained confirmed the necessity of estimating the mitotic index when choosing onion for the Allium test. The necessity resulted from the fact that low proliferative activity could cause false positive results. Sorbic and benzoic acids in concentrations below the corresponding EC50 increased the frequency of chromosomal aberrations in apical meristematic cells of the roots compared to control. Thus, benzoic and sorbic acids had reliable mitodepressive and genotoxic effects on the dividing cells of onion roots. The study explored the dynamics of lipid oxidation biomarker accumulation (malon dialdehyde, MDA) after exposure to benzoic and sorbic acids. The toxic effect of benzoic acid appeared not to be associated with oxidative damage to root cell lipids, whereas sorbic acid in concentrations from 20 to 200 mg/L resulted in a multiple increase in MDA concentration in the test samples compared to control. At the same time, lipid peroxidation showed a higher level of sensitivity compared to other indicators of this test. Further, the data obtained on the toxic influence of sorbic and benzoic acids can be used in express methods to assess food and ecological security of these acids.

Genotoxicity of five food preservatives tested on root tips of Allium cepa L.

The cytogenotoxic effects of emulsifiable concentrate of amitraz pesticides was evaluated using Allium cepa L. test. The root meristems of A. cepa L. were treated with five concentrations (1%, 5%, 10%, 20% and 40%) of the chemical pesticide at 48 h for cytogenetic analyses and 96 h for root length inhibition. Pesticide doses affected root length significantly (P<0.05) at 5% to 40%; with 50% effective concentration (EC50) value of 18% while there was no significant difference between control and 1% (p>0.05). The mean root length of the treated A. cepa for Amitraz pesticides in all concentrations was lower compared to the control showing the obvious mitodepressive effects of amitraz pesticides. A dose dependent reduction in the total mitotic dividing cells and mitotic index was observed in A. cepa treated with the pesticides. The values of mitotic index obtained for amitraz pesticides at 5% (5.20), 10% (4.0), 20% (2.30) and 40% (0.80) were lower than half of the negative control (7.25), which reflect its cytotoxicity. All the concentrations of the pesticides used in the present study induced important abnormalities during mitotic division. These aberrations were: chromosome stickiness, disturbed spindle, anaphase and telophase bridges, chromosome fragments, laggard chromosomes, and c- Mitosis. The highest abnormality number was observed in the root tips of Allium cepa (5%) while the least was at 40%. Frequencies of chromosome abnormalities were low at 20% and 40% concentration because of damaged cell and lower cell divisions. The present study, showed the inhibition of growth and induction of chromosomal aberrations by amitraz, this suggest their capability in inducing cytotoxicity and genome instabilityKeywords: Allium cepa, chromosomes, amitraz pesticides, aberrations, mitotic index

The aim of present study was to assess the cytotoxic and genotoxic potency of lead acetate using an Allium root tip bioassay. Root tips of Allium cepa L. were treated with different concentrations of lead acetate viz., 0.03, 0.06, and 0.09 mg mL-1 of lead acetate for 48 h. Mitotic index (MI), phase index (PI), and total chromosomal abnormalities (TA) were calculated. The effect of lead acetate was found to be dose-dependent. The frequency of MI ranged from 8.4 to 5.7%, PI of prophase from 4.2 to 3.4%, PI of metaphase from 1.14 to 1.11%, PI of anaphase from 1.8 to 0.6%, and PI of telophase from 1.1 to 0.4% The total chromosomal abnormality (TA) ranged from 0.42 to 1.39% The differences between the averages of all the studied properties were significantly affected by the heavy metal lead acetate concentration variant applied. Mitotic observation showed that increasing of concentration variants doses decrease mitotic index and increased chromosomal abnormality percentage. Various types of physiological and clastogenic (laggard, stickiness, abnormal metaphase, chromatin bridge, and delayed anaphase were observed in Allium cepa root tip cells. Moreover, the A. cepa root tip bioassay method gives critical data for evaluating an agent's action mechanisms and impacts on genetic material.

The widespread use of medicinal herbs has raised serious concerns over its quality, safety, and efficacy. Therefore, precise scientific evaluation has become a precondition for acceptance of herbal health claims. In this study the cytogenetic and mutagenesis of morinda citrifolia (noni) aqueous leaves extract on the root tips of Allium cepa was evaluated using Allium cepa (L.) assay, Onion bulb was sun dried for 4 days, the dried outer scales were carefully removed and the root was scraped leaving the ring of the primordial root intact to promote the emergence of new roots. For the root growth inhibition, four concentrations of each extract, viz: 10 g, 15g, 20 g, and 25 g, was considered, with the positive control group treated with glyphosate and the negative control group treated with tap water respectively. The effective concentration (EC50) values of the leaves was determined. The plant extracts induced a dose-dependent root growth inhibitory, mitotic index and mitodepressant effects at 24, 48, 72 and 96 hours. The extracts used induced a relatively low % of chromosomal aberration in the A. cepa root tips cells. In vivo testing of the plants extracts on Allium cepa root-tips revealed that the extract do not induced cytogenetic and mutagenic effect at 10 % concentration, but as the concentration of the plants extracts increases to 15 %, 20 %, 25 %, the leave extracts showed the potency of induce genetic damage at chromosomal level and it spindle apparatus on Allium cepa root-tips. The Aberrations observed were Binucleate, Laggard, Nuclear lesion, Fragmentation, Polyploidy, Dissolution, Vagrant metaphase, Chromosome gap Anaphase Bridge, Micronuclei (MN), and unequal separation. It is therefore suggested that users of morinda citrifolia plants extracts as traditional medicine be advised to always use definite measurement and at lower concentration of 10g, because it has cytogenetic and mutagenesis effect at higher concentration. Keywords: morinda citrifolia, cytogenetic, mutagenesis, chromosome, aberration, Allium cepa

This research aimed to examine the dual effects of Coffea arabica on the cell division of Allium cepa and its antibacterial properties. This was achieved by utilizing the A. cepa bioassay to study mitosis and measuring optimal density, as well as using the agar well diffusion method to evaluate the antibacterial effect against Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis. To study the impact of Coffea arabica on mitosis, root tips of Allium cepa were exposed to three different levels of coffee (1.5, 5.5, and 10.5 g/100 ml). The frequency of chromosomal aberrations (CA) and mitotic index (MI) were observed under a microscope. For the antibacterial effect, the coffee extracts were tested against P. aeruginosa, S. aureus, and B. subtilis using two methods. First, the optimal density of bacterial growth was measured for three different coffee levels (3, 12.5, 20 mg/ml). Second, the agar well diffusion method was used to evaluate the size of the inhibition zones around the wells containing the coffee extract. The results revealed that Coffea arabica at levels of 10.5 g/100 ml and 5.5 g/100 ml significantly affected mitosis in A. cepa root cells, leading to an increase in CA, such as multinucleated cells, chromosomal stickiness, and chromosomal bridges. The MI was also noticeably elevated at these levels. Regarding antibacterial activity, P. aeruginosa was found to be the most susceptible to coffee at 12.5 mg/ml, as indicated by the optical density measurement. The agar well diffusion method showed that S. aureus exhibited the largest inhibition zone (1.9 cm) at 20 mg/ml. This research highlights the dual impact of Coffea arabica on both chromosomal stability and bacterial growth. The coffee extract demonstrated a clear effect on mitosis, causing CA and surged MI in A. cepa root cells. Additionally, coffee exhibited antibacterial properties, particularly against P. aeruginosa and S. aureus. These findings suggest that while coffee has beneficial antimicrobial effects, its impact on cellular processes, such as chromosomal integrity, should also be considered in future studies.

N-nitroso compounds, such as N-nitrosodiethylamine (NDEA), can be formed by the reaction of secondary amines with nitrosating agents, and are suspected to be involved in tumors in humans. NDEA has been considered a weak carcinogen in genotoxic assays probably due to the inefficient nitrosamine activation system that is used and/or to the efficient repair system. In this work, we evaluated the sensibility of Allium cepa L. root tips and Tradescantia stamen hair mutation assay (Trad-SH) using Tradescantia pallida var. purpurea for NDEA (0.1; 0.5; 5 and 25 mM) genotoxicity and mutagenicity induction. Allium cepa L. was treated with different NDEA concentrations for 3h, for 3 consecutive days, including negative control (distilled water) and positive control maleic hydrazide (MH 30 mg/mL). After treatment, the roots were hydrolyzed, squashed, and the mitotic index (MI) and cytological abnormalities were scored. The results revealed a cytostatic effect of NDEA (0.5 and 5mM), showing a significant reduction in the MI. Chromosome stickiness suggests a NDEA toxic effect. T. pallida purpurea did not respond to mutagens with a dose-dependent pattern. In conclusion, our study indicates that the root tips of Allium cepa L. have sensibility to detect NDEA genotoxicity, but not for Trad-SH test.

Parabens (PBs) are alkyl esters of para-hydroxybenzoic acid and are widely used in pharmaceuticals, food and beverages, and cosmetics due to their antimicrobial properties. Parabens are also known as "Endocrine disruptors" and can cause toxicity in different organisms. Parabens, especially methylparaben and propylparaben are also present in many environmental matrices, such as water sources and soil, and can cause cytotoxic and genotoxic effects in different organisms. This study aimed to evaluate the genotoxic and cytotoxic effects of the two most commonly used types of parabens that are methylparaben and propylparaben on meristematic cells in onion root tips by comet assay and cytological anomaly-based evaluation. Root growth inhibition assay was used to evaluate root growth inhibition. A. cepa assay was used to assess mitotic index (MI) and chromosomal aberrations (CAs). DNA damage was assessed by comet assay. The half maximal effective concentration (EC50) on the growth of A. cepa cells calculated for methylparaben and propylparaben was 75 ug/mL (2.70 ± 0.10 cm) and 25 ug/mL (2.70 ± 0.2 cm), respectively. Similarly, dose- and time-dependent decrease in mitotic index (MI), increase in chromosomal aberrations (CAs) and increase in DNA damage were observed by the exposure of A. cepa root tips to methylparaben and propylparaben upon 24 h and 48 h exposure periods. The findings of the study showed that propylparaben is more cytotoxic and genotoxic than methylparaben as evidenced by a significant reduction in MI, along with an increase in chromosomal aberrations and DNA damage when compared to methylparaben.

Ruthenium complexes have attracted much attention as possible building blocks for new transition-metal-based antitumor agents. The present study examines the mitotoxic and clastogenic effects induced in the root tips of Allium cepa by cis-tetraammine(oxalato)ruthenium(III) dithionate {cis-[Ru(C(2)O(2))(NH(3))(4)](2)(S(2)O(6))} at different exposure durations and concentrations. Correlation tests were performed to determine the effects of the time of exposure and concentration of ruthenium complex on mitotic index (MI) and mitotic aberration index. A comparison of MI results of cis-[Ru(C(2)O(2))(NH(3))(4)](2)(S(2)O(6)) to those of lead nitrate reveals that the ruthenium complex demonstrates an average mitotic inhibition eightfold higher than lead, with the frequency of cellular abnormalities almost fourfold lower and mitotic aberration threefold lower. A. cepa root cells exposed to a range of ruthenium complex concentrations did not display significant clastogenic effects. Cis-tetraammine(oxalato)ruthenium(III) dithionate therefore exhibits a remarkable capacity to inhibit mitosis, perhaps by inhibiting DNA synthesis or blocking the cell cycle in the G2 phase. Further investigation of the mechanisms of action of this ruthenium complex will be important to define its clinical potential and to contribute to a novel and rational approach to developing a new metal-based drug with antitumor properties complementary to those exhibited by the drugs already in clinical use.

The aqueous extract of banana fruits peal was tested for its effect on mitosis . The root tips of Allium cepa were used as plant test system and the bone marrow cells of the albino mice Mus musculus were used as mammalians test system in vivo .Root tips of Allium cepa were treated for four hours with five concentrations of the extract (5 , 10 , 20 , 40 ,60 mg / ml.).The Metaphase was arrested in all the treatments , the highest percentage ( 100 % ) was recorded in the first concentration , the last concentration caused stickiness and clumping of the chromosomes. The treatments did not cause significant difference in the mitotic index. The peals extract (5 mg /ml) was compared with the extracts of fruits bulb, leaves and roots of banana plant, it was found that the extract of fruits peal is the best considering the highest percentages of arrested Metaphase in the root tips cells. The albino mice Mus musculus were injected intraperitonial with the peals extract ( 0.01 , 0.02, 0.04, 0.06, 0.08 mg / gm body weight), the percentages of arrested Metaphase in the bone marrow of these animals were comparable to the recorded percentages when the animals were injected with colchicine ( 0.01 mg / gm b.w.) .This study revealed the antimitotic activity of the aqueous extract of banana fruits peal on both the plant and mammalian cells in vivo. Studies will be conducted to investigate the effect of the extract and its components on the proliferation of cancer cells in vitro and in vivo.

The aqueous extract of banana fruits peal was tested for its effect on mitosis . The root tips of Allium cepa were used as plant test system and the bone marrow cells of the albino mice Mus musculus were used as mammalians test system in vivo .Root tips of Allium cepa were treated for four hours with five concentrations of the extract (5 , 10 , 20 , 40 ,60 mg / ml.).The Metaphase was arrested in all the treatments , the highest percentage ( 100 % ) was recorded in the first concentration , the last concentration caused stickiness and clumping of the chromosomes. The treatments did not cause significant difference in the mitotic index. The peals extract (5 mg /ml) was compared with the extracts of fruits bulb, leaves and roots of banana plant, it was found that the extract of fruits peal is the best considering the highest percentages of arrested Metaphase in the root tips cells. The albino mice Mus musculus were injected intraperitonial with the peals extract ( 0.01 , 0.02, 0.04, 0.06, 0.08 mg / gm body weight), the percentages of arrested Metaphase in the bone marrow of these animals were comparable to the recorded percentages when the animals were injected with colchicine ( 0.01 mg / gm b.w.) .This study revealed the antimitotic activity of the aqueous extract of banana fruits peal on both the plant and mammalian cells in vivo. Studies will be conducted to investigate the effect of the extract and its components on the proliferation of cancer cells in vitro and in vivo.