The interaction of Al with Ca in six different combinations was studied in bone marrow chromosomes following daily oral administration for prolonged periods. Cytotoxic effects of Al, measured by the induction of chromosomal aberrations, were countered by treatment with Ca. The protection afforded was maximum when Ca was fed at a ratio of 3:1, as related to Al, 2 hours before the administration of Al.

A K ROY

A SHARMA

G TALUKDER

Fulltext

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

CYTOLOGIA

The identification of desmutagens and bioantimutagens in plants has prompted the search for additional plant extracts capable of modifying adverse cellular effects of environmental toxicants. The protective action of crude extracts of Phyllanthus emblica fruits (PFE) against lead (Pb) and aluminium (Al)‐induced sister chromatid exchanges (SCEs) was studied in bone marrow cells of Mus musculus. The modifying effect of the crude extract was compared with that of comparable amounts of synthetic ascorbic acid (AA), a major component of the fruits. Oral administration of PFE or AA for 7 consecutive days before exposure of mice to the metals by intraperitoneal injections reduced the frequencies of SCEs induced by both metals. PFE afforded a more pronounced protective effect than AA in counteracting the genotoxicity induced by both Al and Pb: This difference was significant with Pb. The higher protection afforded by PFE may be attributed to the interaction of AA with other natural ingredients present in the crude fruit extract. ©1993 Wiley‐Liss, Inc. Copyright © 1993 Wiley‐Liss, Inc., A Wiley Company

Environmental and Molecular Mutagenesis

Relative efficiency of Phyllanthus emblica fruit extract and ascorbic acid in modifying lead and aluminiumâ€induced sisterâ€chromatid exchanges in mouse bone marrow

The interaction between cobaltous chloride and calcium chloride was observed using as endpoints mitotic index and frequency of chromosomal abonrmalities. The two salts were administered orally to laboratory-bred male mice in vivo singly or one followed by the other or both simultaneously. Chromosomes were studied from bone marrow preparations after 24 hr. In all cases, the administration of CaCl2 two hours before CoCl2 protected against the clastogenic effects of the latter to a significant extent. Simultaneous feeding of the two salts reduced the damage by CoCl2 only when CaCl2 was given in a higher concentration. The reduction of clastogenicity of cationic cobalt by calcium has been attribited to the competition between the two ions. This report of the use of Ca2+ in reducing the clastogenicity of Co2+ is a new one. © 1991, Japan Mendel Society, International Society of Cytology. All rights reserved.

Modification of the Clastogenic Effects of Cobalt by Calcium in Bone Marrow Cells of Mice in vivo

The interaction between cesium chloride CsCl and calcium chloride Cal2 was observed in bone marrow chromosomes of mice. The two salts were administered orally to laboratory bred Swiss albino mice in vivo singly or one followed by the other, or both simultaneously. CsCl induced chromosomal aberrations in frequencies directly proportional to the dose administered. The frequency of aberrations was reduced significantly when the two chemicals were administered simultaneously or when CaCl2 was given 2 h before CsCl. Thus, CaCl2 is able to protect against the cytotoxicity of CsCl. © 1991 Humana Press Inc.

Biological Trace Element Research

Modification of cesium toxicity by calcium in mammalian system

Aluminum toxicity is a major factor in limiting growth in plants in most strongly acid soils. Toxic effects on plant growth have been attributed to several physiological and biochemical pathways, although the precise mechanism is still not fully understood. In general, root elongation is hampered through reduced mitotic activity induced by Al, with subsequent increase in susceptibility to drought. The initial site of uptake is usually the root cap and the mucilaginous secretion covering the epidermal cells. Al ions bind very specifically to the mucilage by exchange adsorption on the polyuronic acid, complexing with the pectic substances and by the formation of polyhydroxy forms, increasing the number of Al atoms per positive charge. Toxicity has been suggested to be initiated at the sites of mucopolysaccharide synthesis. Al is absorbed on all Ca-binding sites on the cell surface. In the intact tissues, most of the Al is bound to the pectic substances of the cell wall and a part to the nucleic acids and cell membrane. Al is also reported to enter the plant by moving into meristematic cells via the cortex, bypassing the endodermal barrier. Being a polyvalent cation, it follows principally the apoplasmic pathway of transport through cortical cells, but may also enter the stele through the plasmalemma. Ultrastructural studies have shown the maximum accumulation to be in the epidermal and cortical cells. The interaction of Al with different systems follows different pathways. The plasma membrane at the outer boundary of the root cell is a potential target and its physical properties can be altered by Al through interaction with membrane-bound ATPase, lipids, carbohydrates and proteins. The Golgi apparatus has been suggested as the primary site of action, followed by damage to the plasmalemma. Aluminum interferes with the uptake, transport and use of several essential elements, including Cu, Zn, Ca, Mg, Mn, K, P and Fe. Excess of Al reduces the uptake of certain elements and increases that of others, the patterns being dependent on the element, the plant part and species involved. A major factor is the pH concentration. At an acid pH, below 5.5, the antagonism between Ca and Al is probably the most important factor affecting Ca uptake by plants. The molecular mechanism of tolerance of Al is as yet not clear. Tolerant plants reduce the absorption by the root or detoxify Al after absorption. Al tolerant plants may be grouped into those with higher Al concentrations in tops and those with less. In the latter, more Al is entrapped in roots. Uptake of Al may be reduced by binding to cell wall or to membrane lipid. Tolerance may be different in different species and seems to be controlled by one or more genes. Absorption of Al in non-metabolic conditions is affected only slightly by temperature. Anaerobic conditions, like the presence of nitrogen and metabolic inhibitors, damage the endodermal membrane barrier, increasing the uptake and enhancing injurious effects. Aluminum also causes morphological damage to plant parts. It affects photosynthesis by lowering chlorophyll content and reducing electron flow. Reduced respiratory activity might be due to reduced metabolic energy requirement. Protein synthesis is decreased probably due to effect on ribosome distribution at endoplasmic reticulum. Aluminum is known to bind to DNA and nuclei. However, its penetrance to DNA of mitotically active centers is slow. On accumulating in roots, it initially inhibits mitotic activity, possibly through affecting the integrated control function of the root meristem. Aluminum toxicity in acid soil is of special importance due to the destruction of components of forest ecosystems under specific conditions. It reduces biomass yield and tree growth and represses litter-degrading microflora. Further information is required on the factors affecting membrane permeability, distribution and accumulation of Al in different plant parts and different species. Al tolerance may be studied with relation to the presence of different ligands, nitrogen metabolism (nitrate reductase and protein accumulation), nitrogen tolerance in relation to pH change and metal ion activities, the role of Ca and P and interference with water relations and litter degradation. © 1988 The New York Botanical Garden.

The Botanical Review

Some aspects of aluminum toxicity in plants

Toxicology Letters

ANTAGONISTIC AND SYNERGISTIC EFFECTS OF LEAD AND SELENIUM IN RATTUS-NORVEGICUS

An analysis of the available data on the clastogenic effects of metals and their compounds on higher organisms indicates some general trends. Following chronic exposure to subtoxic doses, a decrease in mitotic frequency and an increase in the number of chromosomal abnormalities are observed. These effects are usually directly proportional to the dose applied and the duration of treatment within the threshold limits. Recovery after acute treatment is inversely related to the dosage. The ultimate expression of the effects depends on certain factors, including the mode and vehicle of administration; the form administered; the test system used; the rate of detoxification, distribution, and retention in the different tissues; and interaction with foreign and endogenous substances as well as the mode of action with the biological macromolecules. In mammals, the clastogenic activity of the metals within each vertical group of the periodic table is directly proportional to the increase in atomic weight, electropositivity, and solubility of the metallic cations in water and lipids, except for Li and Ba. This pattern of inherent cytotoxicity increases with successive periods in the horizontal level. It is enhanced by the formation of covalent and coordinate covalent complexes by heavy metals with the biological macromolecules. In plants, the solubility of the metals in water is of much greater importance. The degree of dissociation of metallic salts and the rate of absorption affect significantly the frequency of chromosomal aberrations. In assessing the effects of environmental metal pollution, the presence of other metals and toxic chemicals and the level of nutrition should be taken into account, since in nature, metals occur in combination and these factors modify the cytotoxic effects to a significant extent. Copyright © 1987 Wiley‐Liss, Inc., A Wiley Company

Journal	CYTOLOGIA
Publisher	J-Stage
ISSN	0011-4545
Open Access	Yes