scholarly journals Effects of water soluble oncostatic fraction from Rheum officinale Baill. rhizomes on Allium cepa root meristem. III. Morphological changes in cytoplasm

2015 ◽  
Vol 45 (4) ◽  
pp. 453-458
Author(s):  
A. Dawidowicz-Grzegorzewska

Spiral concentric and linear configurations of membraneous structures were observed in the cytoplasm of fixed meristematic cells from the root apex of <i>Allium cepa</i> under the light microscope. They appeared after incubation in sublethal and lethal conditions in <i>Rheum ofiicinale</i> rhizome extracts. During postincubation these structures disappeared. They were interpreted as ER membranes. On the basis of literature data the physiological significance of these structures is discussed. It would seem that they are an indication of enhanced metabolic activity evoked either exogenously by various injuries as a form of defence reaction of the protoplast or endogenously during cytodifferentiation. Prolonged treatment in ,noxious conditions causes the ER membranes to transform into inactive myelin structures

2015 ◽  
Vol 45 (4) ◽  
pp. 429-443
Author(s):  
A. Dawidowicz-Grzegorzewska

The effects of the oncostatic extracts from <i>Rheum officinale</i> rhizomes on the activity of meristematic cells from <i>Allium cepa</i> roots were investigated. A statistically significant decrease of the IM value was noted as well as of the total number of mitoses during incubation. The disturbances in the course of mitosis and cytokinesis are described and discussed. The kind of disturbances during postincubation points to damage of the S and G2 phases of the interphase nuclei. Cytochemical and autoradiographic studies demonstrated a diminished intensity of staining of DNA and RNA and inhibition of DNA synthesis during incubation, this leading in tum to a lower intensity of protein staining in postincubation. Disturbances in mitosis and cytokinesis after treatment wth 2,6-dihydroxyantraquinone, supposed to be the antimitotically active compound of the extract, are the same as those produced by the total water soluble fraction.


2015 ◽  
Vol 40 (4) ◽  
pp. 623-631
Author(s):  
J. A. Tarkowska

The effect of water extract from leaves of <i>Nerium oleander</i> L. on the mitosis in meristematic cells of <i>Allium cepa</i> L. root tips has been studied. Observations were made on the changes during incubation and postincubation. Significant disturbances were observed in the development of the mitotic spindle leading to the formation of polyploid and hypoploid nuclei capable of further division. Substances contained in the water extract, and causing the disturbances, are water soluble glycosides. Introductory observations under an electron microscope indicate that the glycosides desorganize the continuous fibres of the spindle which can be considered as the direct cause of the observed disturbances.


2006 ◽  
Vol 290 (4) ◽  
pp. F789-F794 ◽  
Author(s):  
Yasin Tayem ◽  
Tony R. Johnson ◽  
Brian E. Mann ◽  
Colin J. Green ◽  
Roberto Motterlini

Nephrotoxicity is one of the main side effects caused by cisplatin (CP), a widely used antineoplastic agent. Here, we examined the effect of a novel water-soluble carbon monoxide-releasing molecule (CORM-3) on CP-mediated cytotoxicity in renal epithelial cells and explored the potential therapeutic benefits of carbon monoxide in CP-induced nephrotoxicity in vivo. Exposure of LLC-PK1 cells to CP (50 μM) caused significant apoptosis as evidenced by caspase-3 activation and an increased number of floating cells. Treatment with CORM-3 (1–50 μM) resulted in a remarkable and concentration-dependent decrease in CP-induced caspase-3 activity and cell detachment. This effect involved activation of the cGMP pathway as 1H-oxadiazole [4, 3-a] quinoxaline-1-ore (ODQ), a guanylate cyclase inhibitor, completely abolished the protection elicited by CORM-3. Using a rat model of CP-induced renal failure, we found that treatment with CP (7.5 mg/kg) caused a significant elevation in plasma urea (6.6-fold) and creatinine (3.1-fold) levels, which was accompanied by severe morphological changes and marked apoptosis in tubules at the corticomedullary junction. A daily administration of CORM-3 (10 mg/kg ip), starting 1 day before CP treatment and continuing for 3 days thereafter, resulted in amelioration of renal function as shown by reduction of urea and creatinine levels to basal values, a decreased number of apoptotic tubular cells, and an improved histological profile. A negative control (iCORM-3) that is incapable of liberating CO failed to prevent renal dysfunction mediated by CP, indicating that CO is directly involved in renoprotection. Our data demonstrate that CORM-3 can be used as an effective therapeutic adjuvant in the treatment of CP-induced nephrotoxicity.


1976 ◽  
Vol 22 (2) ◽  
pp. 403-411 ◽  
Author(s):  
M.J. Packard ◽  
S.M. Stack

Numerous vesicles were observed among the microtubules of the “preprophase” band in prophase cells from root tips of Allium cepa. The content of these vesicles looks similar to the matrix of adjacent cell walls, and these vesicles often appear to be involved in exocytosis. In addition, the cell walls perpendicular to the plane of (beneath) the preprophase band are often differentially thickened compared to the walls lying parallel to the plane of the band. Our interpretation of these observations is that the preprophase band may direct or channel vesicles containing precursors of the cell wall to localized regions of wall synthesis. The incorporation of constituents of the cell wall into a narrow region defined by the position of the preprophase band may be a mechanism that ensures unidirecitonal growth of meristematic cells.


2009 ◽  
Vol 15 ◽  
pp. 83-88 ◽  
Author(s):  
Prabhakar Bhatta ◽  
S. R. Sakya

The mitotic activity and chromosomal behaviour was observed in four different concentrations of magnesium sulphate at four different duration of treatment using Allium cepa as a biological system. Mito-inhibitory effect of the compound was observed in higher concentration. The compound was capable of producing various chromosomal abnormalities indicating the cytostatic and clastogenic properties of magnesium sulphate. Key words: Allium cepa, magnesium sulphate, mitotic index, phase indices.doi: 10.3126/eco.v15i0.1947 ECOPRINT 15: 83-88, 2008


Biotemas ◽  
2014 ◽  
Vol 28 (1) ◽  
pp. 45 ◽  
Author(s):  
Layana Menezes da Silva ◽  
Ana Paula Peron ◽  
Francisco Ronielson da Silva Carvalho ◽  
Livia Martins ◽  
Iana Felício Bantim Calou ◽  
...  

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