Root Tip Cells Research Articles

Evaluation of Genotoxic and Cytotoxic Activities of Leaf and Seed Extracts of Telfairia occidentalis

Telfairia occidentalis Hook (cucurbitaceae) leaves and seeds, which are used as vegetable in the preparation of soups and as medicine traditionally to treat various diseases by the Ibibios were investigated for genotoxic and cytotoxic effects using Allium cepa test. The effects of the leaves and seeds extracts on the root meristem cells of Allium cepa were investigated using onion bulbs exposed to 2.5 mg/mL, 5 mg/mL, and 10 mg/mL concentrations of the extracts for macroscopic and microscopic analysis. Tap water was used as a negative control and Methotrexate (0.1 mg/ml) was used as a positive control. There was statistically significant (p< 0.05) inhibition of root growth depending on concentration by the extracts when compared with the negative control group. All the tested extracts were observed to have cytotoxic effects on cell division in A. cepa. The extracts-induced chromosomal aberrations and micronuclei (MNC) formations in A. cepa root tip cells were significant (p<0.05) when compared with control group. The extracts treatment further induced cell death, ghost cells, cells membrane damage, and binucleated cells. The seed extract was found to have a higher cytotoxic and genotoxic effects than the leaf extract. These results suggest that the leaf and seeds extract of Telfairia occidentalis possess cytotoxic and genotoxic effects on A. cepa.

Cytotoxic and Genotoxic Potentials of Datura innoxia Leaves Aqueous Extract on Allium cepa Meristemic Cells

Medicinal plants are still vitally important in the preparation of pharmaceutical products. Plants have been used both for their prophylactic effects and for the treatment of illnesses and diseases. According to the World Health Organization (WHO) about 80% of developing countries use traditional folk medicines, 85% of which are plant extracts. Datura plant was used medicinally over the world in historical times for treatment of colds, nervous conditions, and as ointment for cuts or wounds and to relieve pain during the setting of bones. The present study aimed to investigate the mutagenic potential of Datura innoxia water extract using Allium cepa root tip cells as biological systems they were used to find out the effect of Datura extract on chromosomal structure and behavior during cell division. Therefore, the mitotic index and chromosome aberration in treated cells were recorded. The root meristem cells were treated with different concentrations of D. innoxia at different times, cytological analysis revealed significant depression in cell division, this was seen noticeably in all used concentrations especially at high ones. The interaction of D. innoxia extract with the genetic material led to DNA damage and decreased cell number depending concentration and time.

Cytological assessments and a methodological approach to observe the apoptotic effect of nickel sulfate (NiSO4) on Allium cepa L. root germination using EB/AO fluorescence staining

Ethidium bromide–acridine orange (EB/AO) is one of the fastest, most economically valid methods for separating living and dead cells in plant root tips. The present study aimed to investigate the apoptotic effect, nuclear abnormalities and cell division index using an Allium cepa test assay with EB/AO staining and an ImageJ program. Nickel sulphate (NiSO4) concentrations (1.75, 3.5, 7 and 14 ppm) were exposed to the root germination of A. cepa for 48 and 72 h to observe mitotic abnormalities, cytotoxic effects and 5-day exposure to apoptotic effects. It was found that amorphous nuclei, vacuolisation and C-mitosis were the most observed abnormalities, which increased at 14 ppm NiSO4 exposure after 48 and 72 h. The total number of nuclear abnormalities significantly increased at all concentrations and exposure periods. The ImageJ program was used to determine apoptosis rates. The data obtained showed that high concentrations of NiSO4 caused significantly more cell death in root tips than in the control group, resulting in root growth inhibition and increased apoptosis with increased concentration and exposure period. NiSO4 caused toxic activity on root growth, identified as apoptosis, especially at the cortex and vascular region in the root tips. The study found affected damaged and apoptotic areas on the root tips using an EB/AO staining method, which can be used as a marker of damaged tissue areas.

Histological alterations in chilli pepper (Capsicum annuum L.) roots associated with sudden wilt syndrome

AbstractSudden wilt syndrome of chilli, an emerging and destructive disorder, is characterized by an abrupt appearance that has increased in Indo‐Gangetic alluvial plains over the past decade. The primary cause associated with the problem is water stagnation that creates hypoxic conditions in the root zone, and the plant mortality is further aggravated by soil‐borne fungi Fusarium oxysporum. The effects of sudden wilt on chilli roots were studied morphologically and histologically, using root scanning, optical microscopy and electron microscopy. Significant changes with respect to root length, projected area, number of root tips and root segments, average root diameter as well as estimated volume of roots were observed via root scanning of healthy and diseased root samples. Through optical microscopy of sections of the microtome‐cut root junctions displayed normal epidermis in healthy plants, while swollen cells indicated stress in the diseased plants. Cells of laterals and root tips in healthy plants were intact and stained strongly, but because of damaged tissues, cells in diseased plants were macerated and stained weakly. Root tips of healthy plants contained mitotic zones, whereas diseased root tips lacked mitotic zones. Electron microscopy studies revealed that sudden wilt had an adverse impact on xylem diameter, stele diameter, epidermal thickness and cortex thickness as evidenced by significantly lesser values of these parameters. The present study is the first systematic attempt to examine the morphological, histological and ultrastructural changes in chilli in response to sudden wilt syndrome.

Investigation of chromosomal genetic characteristics and identification of structural variation in the offspring of hexaploid triticale×hexaploid wheat.

Hexaploid triticale is an important genetic resource for genetic improvement of common wheat, which can broaden the genetic basis of wheat. In order to lay a foundation for the subsequent research and utilization of triticale germplasm materials, the chromosomal genetic characteristics of cross and backcross offspring of hexaploid triticale×hexaploid wheat were investigated in the process of transferring rye chromatin from hexaploid triticale to hexaploid wheat. Hybrid and backcross combinations were prepared with hexaploid triticale 16yin171 as the maternal parent and hexaploid wheat Chuanmai62 as the paternal parent. The chromosomes in root tip cells of F1, BC1F1 and BC1F2 plants were traced and identified non-denaturing florescence in situ hybridization (ND-FISH). The results indicated that the backcross setting rate of hybrid F1 was 2.61%. The transmission frequency of 2R chromosome was the highest in BC1F1 plants while the transmissibility of rye chromosome in BC1F2 plant was 6R>4R>2R, and the 5B-7B wheat translocation in BC1F2 plants showed severe segregation. A total of 24 structural variant chromosomes were observed both in BC1F1 and BC1F2 plants, including chromosome fragments, isochromosomes, translocations, and dicentric chromosomes. In addition, the seed length and 1000-grain weight of some BC1F2 plants were better than that of the hexaploid wheat parent Chuanmai 62. Therefore, multiple backcrosses should be adopted as far as possible to make the rapid recovery of group D chromosomes, ensuring the recovery of fertility in offspring, when hexaploid tritriale is used as a bridge to introduce rye genetic material into common wheat. At the same time, the potential application value of chromosomal structural variation materials should be also concerned.

Rhizospheric nano-remediation salvages arsenic genotoxicity: Zinc-oxide nanoparticles articulate better oxidative stress management, reduce arsenic uptake, and increase yield in Pisum sativum (L.)

Pea (Pisum sativum L.), a legume, has a high nutritional content, but arsenic (As) in the agro-ecosystem poses a significant bottleneck to its yield, especially in South East Asia, by severely hampering ontogeny. The present study proposes a rhizospheric nano-remediation strategy to evade As-genotoxicity and improve crop yield using biogenic zinc-oxide nanoparticles (ZnONPs). Similar to any other source of environmental stress, As-toxicity caused rapid oxidative bursts with deterioration in morpho-physiological attributes (germination rate, shoot length, and root length decreased by 62 %, 16 %, and 14.9 % respectively in the negative control, over normal control). Reactive oxygen species (ROS) accumulation (12.8 and 9-fold increase in leaves and roots) overburdened antioxidative defense, and loss of cellular homeostasis resulted in membrane damage (82.75 % increase) and electrolyte-leakage (2.6-fold increase) in negative control. The study also reveals a significant increase in nuclear area, nuclear fragmentation, and micronuclei formation in root tip cells under As-stress, indicating severe genomic instability and increased programmed cell death (3.3-fold increase in early apoptotic cells) due to leaky plasma membrane and unrepaired DNA damage. Application of ZnONPs significantly reduced As-toxicity in peas due to its adsorption in the rhizosphere, causing diminished As-uptake and better antioxidant response. Improved phytochelatin synthesis enhanced vacuolar sequestration of arsenic, which reduced As-interference. Comparatively better flowering time (7.74–19.36 % reduction in flowering delay) with greater transcript abundance of GIGANTIA (GI), CONSTANS (CO), and FLOWERING LOCUS T (FT) genes; better photosynthetic activity (1.3–1.9-fold increased chlorophyll autofluorescence); increased pollen viability; lesser genotoxicity (decreased tail DNA in comet assay) was noticed. A maximum increase of 37.5 % in pod number and seed zinc content (1.67-fold) was observed while seed arsenic content decreased under ZnONPs treatment. However, the highest dose of ZnONPs (400 mg L−1) induced NP-toxicity in pea plants under our experimental conditions, while optimum stress-alleviation was observed up to 300 mg L−1.

Phosphorylation Dynamics in a flg22-Induced, G Protein–Dependent Network Reveals the AtRGS1 Phosphatase

The microbe-associated molecular pattern flg22 is recognized in a flagellin-sensitive 2–dependent manner in root tip cells. Here, we show a rapid and massive change in protein abundance and phosphorylation state of the Arabidopsis root cell proteome in WT and a mutant deficient in heterotrimeric G-protein–coupled signaling. flg22-induced changes fall on proteins comprising a subset of this proteome, the heterotrimeric G protein interactome, and on highly-populated hubs of the immunity network. Approximately 95% of the phosphorylation changes in the heterotrimeric G-protein interactome depend, at least partially, on a functional G protein complex. One member of this interactome is ATBα, a substrate-recognition subunit of a protein phosphatase 2A complex and an interactor to Arabidopsis thaliana Regulator of G Signaling 1 protein (AtRGS1), a flg22-phosphorylated, 7-transmembrane spanning modulator of the nucleotide-binding state of the core G-protein complex. A null mutation of ATBα strongly increases basal endocytosis of AtRGS1. AtRGS1 steady-state protein level is lower in the atbα mutant in a proteasome-dependent manner. We propose that phosphorylation-dependent endocytosis of AtRGS1 is part of the mechanism to degrade AtRGS1, thus sustaining activation of the heterotrimeric G protein complex required for the regulation of system dynamics in innate immunity. The PP2A(ATBα) complex is a critical regulator of this signaling pathway.

Cytotoxic and genotoxic effects of triphenyl phosphate on root tip cells of Allium cepa L.

Triphenyl phosphate (TPhP) is a tri-ester of phosphoric acid and phenol. It is used in products such as polyvinyl chloride, hydraulic fluids, polymers, photographic films and printed circuit cards as a flame retardant. It is also widely used in consumer products like electric and electronic devices, textiles and building necessaries. TPhP can diffuse into its surrounding environment easily, because it does not form a chemical bond with polymeric materials. Therefore, bio-monitoring of such compounds is needed for possible environmental and human health effects. In this study, we evaluated genotoxicity and cytotoxicity of TPhP on Allium cepa on the cells of root tips. A 10 mg/mL stock solution of TPhP was dissolved in DMSO and dilutions of 2, 4, 6, 8 and 10 mg/mL was made in distilled water. Onion bulbs, rooted in test tubes, were exposed to these concentrations of TPhP for 24 h. Distilled water was used as a negative control, 0.7% hydrogen peroxide was used as positive control, and 0.5% DMSO was used as solvent control. Significant inhibition of onion root growth was observed following treatment with the 6, 8 and 10 mg/mL TPhP ranges in comparison with the negative and solvent control groups (p < 0.05). Furthermore, in the TPhP treatment groups, total chromosome aberration ratios were significantly high in comparison with the controls (p < 0.05). These results suggest that TPhP have cytotoxic and genotoxic effects on A. cepa root tips.

Silicon alleviates autotoxicity by regulating membrane lipid peroxidation and improving photosynthetic efficiency in cucumber seedlings (Cucumis sativus L.)

Autotoxicity is one of the main causes of cucumber continuous cropping obstacles. Cinnamic acid (CA), a phenolic acid derivative, acts as an autotoxin found in cucumber root exudates. The autotoxicity mimicked by CA significantly increases membrane lipid peroxidation in root and leaf cells, resulting in damage to the structure and function of root tip cells and leaf cells. It also injures the activity of photosystem PSII, reducing the photosynthetic rate and inhibiting the growth of cucumber plants. Supplementing Si alleviates CA-mimicked autotoxicity by increasing the thickness and smoothness of root tip cell walls, inhibiting the absorption and accumulation of CA, as well as relieving osmotic stress and membrane lipid peroxidation caused by CA in cucumber roots and leaves. Additionally, Si promotes grana lamella (GL) stacking and increases thylakoid numbers in chloroplasts. It also enhances the chlorophyll content in cucumber leaves and improves the energy conversion efficiency of photosystem PSII. These effects lead to an improvement in both photosynthetic efficiency and dry matter accumulation, as well as increased the resistance to CA-induced autotoxicity in cucumber plants. The same concentration of Si had no significant effect on the growth of cucumber seedlings, indicating that Si plays an important role in improving the tolerance to autotoxicity in cucumbers. These findings provide an effective theoretical basis and methods for research regarding the alleviation of continuous cropping obstacles.

Methanolic root peel extract of Potentilla fulgens L. shows anti-proliferative activity on root meristematic cells of Lathyrus sativus L. and antiamoebic activity on trophozoites of Entamoeba histolytica

Native inhabitants of North-East India traditionally use Potentilla fulgens as a folk remedy for various diseases, including intestinal parasitic infections. P. fulgens root extract is enriched with catechin, afzelechin, fulgic acid and gallic acid like anticancer compounds. The cytotoxicity of P. fulgens root extract was confirmed on various human cancer cell lines. The potency of plant-based assay systems is increasingly apparent for the primary screening of plant extracts with cytotoxic effects. Various anti-proliferative activity assays utilizing the cell cycle attributes of Lathyrus sativus have been studied against different anticancer drugs and plant extracts. However, further validation of those plant extracts' cytotoxicity on human cancer cells is required for benchmarking plant-based assay system with classical methods based on malignant cells. Here, we have shown the effect of P. fulgens methanolic root extract on L. sativus root tip cells to revalidate the assay system. A significant reduction in the mitotic index was observed upon treatment of the L. sativus seeds with the plant extract. The extract caused reversion of colchicine induced polyploidy of L. sativus root cells comparably with anticancer drug cisplatin. Additionally, in silico interaction studies of catechin with the human DNMT1, anticancer drug target, and plant MET1 enzyme were performed. Our result showed that crucial residues important for catechin binding were conserved in the orthologs despite of their evolutionary divergence. This study also revealed that the treatment of 700 μg/ml of methanolic extract retarded the growth of Entamoeba histolytica by 60 % with a change in trophozoite shape compared to control indicated potential antiamoebic activity of the extract.

Uptake, accumulation and toxicity of short chain chlorinated paraffins to wheat (Triticum aestivum L.)

Short chain chlorinated paraffins (SCCPs) are ubiquitous persistent organic pollutants. They have been widely detected in plant-based foods and might cause adverse impacts on humans. Nevertheless, uptake and accumulation mechanisms of SCCPs in plants remain unclear. In this study, the soil culture data indicated that SCCPs were strongly absorbed by roots (root concentration factor, RCF>1) yet limited translocated to shoots (translocation factor<1). The uptake mechanism was explored by hydroponic exposure, showing that hydrophobicity and molecular size influenced the root uptake and translocation of SCCPs. RCFs were significantly correlated with logKow values and molecular weights in a parabolic curve relationship. Besides, it was extremely difficult for SCCPs to translocate from shoots back to roots via phloem. An active energy-dependent process was proposed to be involved in the root uptake of SCCPs, which was supported by the uptake inhibition by the low temperature and metabolic inhibitor. Though SCCPs at environmentally relevant concentrations had no negative impacts on root morphology and chlorophyll contents, it caused obvious changes in cellular ultrastructure of root tip cells and induced a significant increase in superoxide dismutase activity. This information may be beneficial to moderate crop contamination by SCCPs, and to remedy soils polluted by SCCPs with plants.

Genotoxic Potential, Total Flavonoid and Phenolic Contents of Solanum anomalum Thonn. Ex Schumach Leaf

Solanum anomalum, a medicinal plant, used in ethnomedicine for their antimalarial, antidiabetic, and antiphlogistic activities was investigated for cytotoxic and genotoxic effects on the root meristem cells of Allium cepa. The extract and fractions was also screened for total flavonoid and phenol content using standard methods. Onion bulbs were exposed to 2.5 mg/mL, 5mg/mL, and 10 mg/mL concentrations of the leaf extract for macroscopic and microscopic analysis. Tap water was used as a negative control and Methotrexate (0.1 mg/mL) as a positive control. There was statistically significant (P &lt; 0.05) inhibition of root growth depending on concentration by the extract when compared with the negative control group. All the tested concentrations of the extract were observed to have cytotoxic effects on cell division in A. cepa. The extract- induced chromosomal aberrations and micronuclei (MNC) formations in A. cepa root tip cells were significant (p&lt;0.05) when compared with control group. The extract treatment further induced cell death, ghost cells, cells membrane damage, and binucleated cells. The dichloromethane fraction was found to contain the highest level of total flavonoid and phenol followed by the crude extract. These results suggest that Solanum anomalum leaf extract possess cytotoxic and genotoxic effects on A. cepa which is as a results of its phytochemical constituents.

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

Effect of Household Detergent on Mitotic Root Tip Cells of Vigna unguiculata (Cowpea)

Effect of Household Detergent on Mitotic Root Tip Cells of Vigna unguiculata (Cowpea)

Eco-corona formation diminishes the cytogenotoxicity of graphene oxide on Allium cepa: Role of soil extracted–extracellular polymeric substances in combating oxidative stress

Graphene oxide (GO) is widely acknowledged for its exceptional biological and industrial applications. However, its discharge into the environment negatively impacts the ecosystem. This study aimed to investigate the toxicity of GO in Allium cepa root tip cells and the role of extracellular polymeric substances (EPS) in modulating its toxic effects. To evaluate toxicity, various endpoints like cell viability using Evans blue dye, cytotoxicity (mitotic index), genotoxicity (chromosomal aberrations), and oxidative stress assessments (total ROS, superoxide, hydroxyl radical production, and lipid peroxidation) were considered. The results suggest that pristine GO caused a dose-dependent increase in various toxicity parameters, especially the genotoxic effects. Oxidative stress generation by GO is proposed to be the principal mode of action. The EPS-corona formed on GO could potentially counteract the toxic effects, substantially reducing the oxidative stress within the cells.

The response of Arabidopsis to the apocarotenoid β-cyclocitric acid reveals a role for SIAMESE-RELATED 5 in root development and drought tolerance

Abstract New regulatory functions in plant development and environmental stress responses have recently emerged for a number of apocarotenoids produced by enzymatic or nonenzymatic oxidation of carotenoids. β-Cyclocitric acid (β-CCA) is one such compound derived from β-carotene, which triggers defense mechanisms leading to a marked enhancement of plant tolerance to drought stress. We show here that this response is associated with an inhibition of root growth affecting both root cell elongation and division. Remarkably, β-CCA selectively induced cell cycle inhibitors of the SIAMESE-RELATED (SMR) family, especially SMR5, in root tip cells. Overexpression of the SMR5 gene in Arabidopsis induced molecular and physiological changes that mimicked in large part the effects of β-CCA. In particular, the SMR5 overexpressors exhibited an inhibition of root development and a marked increase in drought tolerance which is not related to stomatal closure. SMR5 up-regulation induced changes in gene expression that strongly overlapped with the β-CCA–induced transcriptomic changes. Both β-CCA and SMR5 led to a down-regulation of many cell cycle activators (cyclins, cyclin-dependent kinases) and a concomitant up-regulation of genes related to water deprivation, cellular detoxification, and biosynthesis of lipid biopolymers such as suberin and lignin. This was correlated with an accumulation of suberin lipid polyesters in the roots and a decrease in nonstomatal leaf transpiration. Taken together, our results identify the β-CCA–inducible and drought-inducible SMR5 gene as a key component of a stress-signaling pathway that reorients root metabolism from growth to multiple defense mechanisms leading to drought tolerance.

Genotoxic and Cytotoxicity Activities of Leaf Extract of Setaria megaphylla

Setaria megaphylla a medicinal plant, used in ethnomedicine for the treatment of malaria, diabetes and inflammatory diseases was investigated for cytotoxic and genotoxic effects on cells of the root meristem of Allium cepa. Bulbs of Onion were exposed to 2.5 mg/ml, 5mg/ml, and 10 mg/ml concentrations of the leaf extract for macroscopic and microscopic study. Tap water was used as a negative control and Methotrexate (0.1 mg/ml) as a positive control. Depending on concentration by the extract, there was statistically significant (P &lt; .05) inhibition of root growth when compared with the negative control group. All the tested concentrations of the extract were observed to have cytotoxic effects on cell division in A. cepa. The extract- induced micronuclei (MNC) formations and chromosomal aberrations in A. cepa root tip cells were significant (P &lt; .05) when compared with control group. The extract treatment further induced, ghost cells, cells membrane damage, cell death, and bi nucleated cells. These results implies that Setaria megaphylla leaf extract possess cytotoxic and genotoxic effects on A. cepa which is as a results of its phytochemical constituents.

Synthesis and Biological Toxicity Evaluation of Red Light-Emitting Carbon Quantum Dots

This study delineates the successful fabrication of red light-emitting carbon quantum dots (R-CQDs), approximately 3.5 nm in size, via hydrothermal methods. These carbon quantum dots (CQDs) display distinctive fluorescence properties, particularly a laser-dependency. The infrared and Raman spectra were subjected to a thorough investigation, revealing the presence of hydroxyl, amino, and carboxyl groups on the surface of the CQDs. Experimental findings indicate a significant correlation between the antibacterial effect of R-CQDs on E. coli and Yeast and their concentration. Subsequent research suggests that this antibacterial activity primarily stems from the CQDs’ disruption of cell membrane integrity, leading to the leakage of intracellular substances and consequently inhibiting the growth of these two microorganisms. The study also reveals that R-CQDs can trigger chromosomal aberrations in the root tip cells of broad beans and induce micronuclei formation. The frequency of micronuclei is directly proportional to the CQDs dosage, and an extended treatment duration results in an increased micronucleus rate. This suggests potential damage to the genetic material of broad beans by CQDs, which could adversely affect their growth and development. The study further identifies a significant impact of R-CQDs on the height of rice seedlings, causing a substantial reduction. Moreover, it was found that CQDs can infiltrate the rice body and instigate oxidative stress responses.

Magnesium oxyhydroxide nanoparticles: Synthesis, characterization and evaluation of their genotoxicity in Vicia faba L.

Magnesium oxyhydroxide nanoparticles (MgO/Mg(OH)2-NPs) were synthesized by a chemical route and their toxicity were evaluated using Vicia faba L. The obtained solids were characterized using visible infrared and ultraviolet spectroscopy, X-ray diffraction (XRD), electron microscopy and surface area by the BET method. The results indicated the presence of two phases: periclase (MgO) and brucite (Mg(OH)2). These MgO/Mg(OH)2 were <50 nm in size, with band gap energy between 5.95 and 6.12 eV and Urbach energy of ∼340 meV. To determine toxicological endpoints, such as mitotic index (MI) and micronucleus induction (MN), Vicia faba L. root tip cells were treated with suspensions containing concentrations of 12.5, 25, 50 and 100 mg/L of MgO/Mg(OH)2-NPs. The results of the toxicological evaluation showed a decrease in MI in the roots of Vicia faba L. exposed to NPs and a positive correlation between the percentage of cells with MN and the concentrations of MgO/Mg(OH)2-NPs used.

Genotoxic and Cytotoxic Activities of Hippocratea africana Loes. Ex. Engl. Celastraceae Root Extract

Hippocratea africana, a medicinal plant, used in ethnomedicine for the treatment of antimalarial, diabetes, poisoning and inflammatory diseases was investigated for cytotoxic and genotoxic effects on the root meristem cells of Allium cepa. The extract and fractions was also screened for total flavonoid and phenol content using standard methods. Onion bulbs were exposed to 2.5 mg/ml, 5mg/ml, and 10 mg/ml concentrations of the leaf extract for macroscopic and microscopic analysis. Tap water was used as a negative control and Methotrexate (0.1 mg/ml) as a positive control. There was statistically significant (P &lt; 0.05) inhibition of root growth depending on concentration by the extract when compared with the negative control group. All the tested concentrations of the extract were observed to have cytotoxic effects on cell division in A. cepa. The extract- induced chromosomal aberrations and micronuclei (MNC) formations in A. cepa root tip cells and were significant (p&lt;0.05) when compared with control group. The extract treatment further induced cell death, ghost cells, cells membrane damage, and binucleated cells. These results suggest that Hippocratea africana root extract possess cytotoxic and genotoxic effects on A. cepa which is as a results of its phytochemical constituents.