Extracts affecting mitotic division in root-tip meristematic cells

Biologia ◽  
2008 ◽  
Vol 63 (5) ◽  
Author(s):  
Greice Lubini ◽  
Juliana Fachinetto ◽  
Haywood Laughinghouse ◽  
Juçara Paranhos ◽  
Antonio Silva ◽  
...  

AbstractSome species of Psychotria (Rubiaceae) are important in herbal medicine, where their extracts are used internally for infections of the female reproductive system, bronchitis, gastrointestinal disturbances, skin irritations, tumors, ulcers, and eye disturbances. The antiproliferative and genotoxic effects of Psychotria myriantha Mull. Arg. and P. leiocarpa Cham. et Schlecht infusions on the Allium cepa L. cell cycle were evaluated. The teas were prepared by infusing the leaves in distilled water, in two concentrations: 1.13 mg/mL and 6.78 mg/mL. Three groups of four bulbs were used for each Psychotria species. After the bulbs rooted in distilled water, they were transferred to the teas for 24 hours, except for the control that stayed in water. The rootlets were then collected, fixed in ethanol-acetic acid (3:1) for 24 hours, and stored in 70% ethanol. For each group of bulbs, 4000 cells were analyzed, calculating the mitotic indexes, submitting them to statistic analysis, using the χ 2 test (p = 0.05). The results showed a decrease in mitotic index with an increase in tea concentration in both species. In P. leiocarpa, the mitotic index values differed significantly between the control and concentration of 6.78 mg/mL (χ 2 = 9.863). For P. myriantha, the values referring to the mitotic index differed greatly between the control and the treatments (χ 2 = 124.8). With this study, it was determined that P. myriantha and P. leiocarpa infusions possess antiproliferative effects on the A. cepa cell cycle, and teas of P. myriantha also have genotoxic activity.

2019 ◽  
pp. 71-78

EFECTOS DEL SORBATO DE POTASIO A DIFERENTES CONCENTRACIONES y TIEmPO DE ExPOSICIóN SOBRE EL CICLO CELULAR y EL mATERIAL GENÉTICO EN mERISTEmOS RADICULARES DE AllIuM CEPA l. (CEBOLLA) EFFECT OF POTASSIUm SORBATE AT DIFFERENT CONCENTRATIONS AND ExPOSURE TImE ON THE CELL CyCLE AND THE GENETIC mATERIAL IN ROOT mERISTEmS OF AllIuM CEPA l “ONION” Joselyne Quispe, José Saldaña, Tony Verde y Shirley Valderrama Universidad Nacional de Trujillo, Trujillo,Perú DOI: https://doi.org/10.33017/RevECIPeru2010.0011/ RESUMEN Con el propósito de determinar el efecto del Sorbato de Potasio sobre el ciclo celular en meristemos radiculares de Allium cepa L. “cebolla” se establecieron tres grupos experimentales que se expusieron a las soluciones de Sorbato de Potasio en concentraciones de 0.5, 1 y 2 g/L; por 6, 7 y 8 horas cada una y un grupo control. Luego se realizó la respectiva coloración en Orceína acética al 2% de acuerdo a la técnica de Tjio y Levan, observándose con el microscopio compuesto un total de 1500 células meristemáticas en cada uno de los tratamientos. Los resultados aplicando tratamiento después de 8 horas de exposición a la concentración de 2 g/L mostraron una disminución del índice mitótico de 11.26 %, mientras que se incrementó el índice profásico en 95.57 %. Se produjeron también alteraciones como rupturas cromosómicas, puentes anafásicos y células binucleadas. Las pruebas y análisis de varianza, mostraron diferencias significativas entre los diferentes tratamientos, confirmado mediante la prueba de comparación múltiple de promedios de Duncan. Se evidencia un probable efecto genotóxico en el material genético por el Sorbato de Potasio y una alteración en el ciclo celular de los meristemos de A. cepa L.; así mismo, se comprueba la función de biosensor de A. cepa L. en el estudio de sustancias que puedan afectar el ciclo celular. Palabras clave: Allium cepa, Sorbato de Potasio, Índice Mitótico, Alteración del material genético, Puentes anafásicos, Rupturas cromosómicas, Células binucleadas. ABSTRACT In order to determine the effect of Potassium Sorbate on the cell cycle in root meristems of Allium cepa L. “onion” set three experimental groups were exposed to solutions of Potassium Sorbate at concentrations of 0.5, 1 and 2g /l, for 6, 7 and 8 hours each and a control group. Later the respective color in 2% Acetic orcein according to the technique of Tjio and Levan, observed with the compound microscope a total of 1500 meristematic cells in each of the treatments. The appropriate treatment results after 8 hours of exposure to the concentration of 2 g / L showed a decrease in mitotic index of 11.26%, while it increased the rate at 95.57% prophasic index. There were also alterations as chromosome breaks, anaphasic bridges and binucleated cells. The tests and analysis of variance showed significant differences between the different treatments, as confirmed by multiple comparison test of Duncan averages. It shows a probable genotoxic effect in the genetic material by Potassium Sorbate and an alteration in the cell cycle of meristems of A. cepa L., likewise, is found biosensor function of A. cepa L. in the study of substances that may affect the cell cycle. Keywords: Allium cepa, Potassium Sorbate, Mitotic index, Abnormal genetic material, Chromosomal breaks, Anafasic bridges, Binucleated cells.


2008 ◽  
Vol 5 (4) ◽  
pp. 492-499
Author(s):  
Baghdad Science Journal

This study was carried out to investigate the cytogenetic effects of crude aqueous extract of Lycium barbarum on the roots tip of Allium cepa Using three concentration 125, 25, 50 mg/ ml for 2, 4, 6 hours treatment periods.This study were included some cytogenetic analysis such as mitotic index , phase index and chromosome aberration. The data showed that the treatment with 50mg/ml for 6huors led to reduce the mitotic index less than 50% . This reduction considered to have toxic and sublethal effect . These results revealed mutagenic potency by inducing differents type of chromosome aberration.


Biologia ◽  
2007 ◽  
Vol 62 (3) ◽  
Author(s):  
Tülay Çelik ◽  
Özlem Aslantürk

AbstractLavandula genus is an important member of Labiatae (Lamiaceae) family. People use commonly Lavandula stoechas as a medicinal plant for various diseases around the world and also in Turkey. The aim of this study was to investigate cytotoxic and genotoxic effects of aqueous extracts (40, 80 and 120 g/L) from L. stoechas flowers on Allium cepa root tip meristem cells. For this purpose, A. cepa onion bulbs were treated with the above-mentioned L. stoechas flower extracts for 72 h. Spring water (pH 7.3) was used as a control. The result of this study sowed that aqueous extracts reduced mitotic index, but induced chromosome aberrations and mitotic aberrations in comparison with control, significantly (p < 0.05). Aqueous extracts induced breaks, stickiness, pole deviations and micronuclei. Furthermore, these effects were related to extract concentrations. These results showed that L. stoechas aqueous extracts have cytotoxic and genotoxic effects.


Genetics ◽  
1995 ◽  
Vol 141 (4) ◽  
pp. 1473-1481 ◽  
Author(s):  
J Liu ◽  
K Song ◽  
M F Wolfner

Abstract The fs(1)Ya protein (YA) is an essential, maternally encoded, nuclear lamina protein that is under both developmental and cell cycle control. A strong Ya mutation results in early arrest of embryos. To define the function of YA in the nuclear envelope during early embryonic development, we characterized the phenotypes of four Ya mutants alleles and determined their molecular lesions. Ya mutant embryos arrest with abnormal nuclear envelopes prior to the first mitotic division; a proportion of embryos from two leaky Ya mutants proceed beyond this but arrest after several abnormal divisions. Ya unfertilized eggs contain nuclei of different sizes and condensation states, apparently due to abnormal fusion of the meiotic products immediately after meiosis. Lamin is localized at the periphery of the uncondensed nuclei in these eggs. These results suggest that YA function is required during and after egg maturation to facilitate proper chromatin condensation, rather than to allow a lamin-containing nuclear envelope to form. Two leaky Ya alleles that partially complement have lesions at opposite ends of the YA protein, suggesting that the N- and C-termini are important for YA function and that YA might interact with itself either directly or indirectly.


2009 ◽  
Vol 50 (5) ◽  
pp. 457-468 ◽  
Author(s):  
Antonio ANTOCCIA ◽  
Antonella SGURA ◽  
Francesco BERARDINELLI ◽  
Maria CAVINATO ◽  
Roberto CHERUBINI ◽  
...  

2020 ◽  
Author(s):  
Beili Chen ◽  
Jianying Guo ◽  
Ting Wang ◽  
Qianhui Lee ◽  
Jia Ming ◽  
...  

ABSTRACTThe first mitotic division in mammalian zygotes is unique. The fertilized egg reactivates its cell cycle, and the maternal and paternal genomes start to reprogram to become totipotent. The first division is very sensitive to a range of perturbations, particularly the DNA damage, leading to the embryo’s failure to enter the first mitosis. We discovered that a point mutation in the human CHEK1 gene resulted in an Arginine 442 to Glutamine change at the C-terminus of the CHEK1 protein. CHEK1 R442Q mutation caused the zygote to arrest just before the first division. Heterozygote individuals appeared to be healthy except that the female carriers are infertile. Expressing the corresponding mouse mutant Chk1 protein in zygotes also caused arrest before the first mitosis. Treating Chk1 R442Q mouse zygotes with low concentrations of CHEK1 inhibitor enabled the embryos to overcome the cell cycle arrest and resume normal development. Our results revealed an unexpected zygote mitotic checkpoint, which is extremely sensitive to the CHEK1 kinase activity. The fine-tuning of the DNA damage checkpoint permits the arrested one-cell embryos to overcome the first mitotic block and develop into healthy animals. These findings have important implications in assisted human reproduction.


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