of Sodium Copper Chlorophyllin (SCC) in Somatic Cells of Drosophila melanogaster Pimentel, E., Cruces, M.P., Zimmering, S. On the persistence of the. Sodium Copper Chlorophyllin (SCC) Induces Genetic Damage in Postmeiotic and Somatic Wing Cells of Drosophila melanogaster. Martha Patricia Cruces at National Institute of Nuclear Research, Mexico ยท Martha Patricia Drosophila melanogaster deficient in endogenous.

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Several epidemiological studies have reported the relation between chromium exposure used in different industrial processes and cancer risk. Evidence indicates that the hexavalent form is mutagenic and carcinogenic. Chemoprevention has emerged as a good strategy for reducing the risk from exposure to heavy metals.

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There is evidence that some tetrapyrrols such as protoporphyrin IX PP-IXa porphyrin without a metal center and which is a precursor of hemoglobin and cytochrome, acts as an antioxidant modulating the induction of antioxidant enzymes. The present study was performed to evaluate their antimutagenic potential of PP-IX against genetic damage induced by chromium trioxide CrO 3.

The wing spot test was used. Groups of 48 h-old larvae were pretreated for 24 h with 0, 0. The results indicated that the lower PP-IX concentration 0. Absence of an inhibitor effect of PP-IX against 20 Gy gamma rays suggested that this porphyrin acted primarily by forming complexes with chromium at low doses, inactivating its genotoxic action rather than capturing or inactivating the reactive oxygen species generated by the chromium.

Exposure to environmental pollutants of anthropogenic origin is associated with an important increase of chronic degenerative diseases including cancer [1]. Although heavy metals are present naturally in soils, their contamination is caused directly by industrial and mining activities.

They are not chemically or biologically degradable components which accumulate in the soil. If additionally the metals are filtered in groundwater, control is very difficult and the metals can enter the food chain, either through drinking water or through consuming contaminated crops in agricultural soils, becoming druces potential health risk [2].

They have been associated with diseases such as pneumonia, renal dysfunction, emphysema, and bone cancer [3]as well as with an impaired nerve function system [4]. Given this situation, the need arises to implement strategies that will reduce the occurrence of degenerative diseases.

The first, and the most obvious, is to avoid exposure of human beings to those agents that have the ability to modify the genetic material and, therefore, increase the risk of diseases such as cancer. However, in practice this is almost impossible since many of such agents are found naturally in the atmosphere as ultraviolet or ionizing radiationand others are products of the metabolism of innocuous compounds such as nitrates [5].

The second alternative is to increase the consumption of substances capable of preventing or reducing the adverse effects of mutagenic and carcinogenic agents. This strategy refers to chemoprevention and it is defined as the use of chemical compounds, crcues those of natural origin that melankgaster inhibition or reversal of mutagenesis or carcinogenesis in the premalignant state melanogasteer. Among melanogaater metals, chromium is considered one of the most dangerous and the International Agency of Research on Cancer [6] recognized the carcinogenicity of this metal.

One of the biggest sources of Cr VI exposure is through ccruces release of particles during stainless steel solder [7][8]. Exposure pathways include the following: Chromium has been reported to be melankgaster into the body through the bone marrow, lungs, lymph nodes, spleen, kidney, and liver [10][11]. The deosophila of this element is known to occur during the reduction process of Cr VI to Cr IIIgenerating reactive oxygen species ROS that interact with the genetic material and are able to induce various alterations, for example: Not only are workers in manufacturing industries exposed to chromium compounds, but also the general public is exposed through cigarette smoke, automobile emissions, landfills, and drosiphila waste disposal sites [12].


Among the natural compounds with chemoprevention properties, porphyrins are aromatic heterocyclic macrocycles derived from the porphine base structure. They are considered promising mainly because of their low toxicity. These molecules have the ability to form complexes directly with planar polycyclic structures thereby preventing their interaction with DNA; however, tetrapyrroles can also be interspersed in the molecule [10].

The antimutagenic activity of porphyrins containing some metal ion is due to their antioxidant effect [13][14][15]. Protoporphyrin-IX is a molecule with no metal core, it comes from the biosynthesis of melanogastfr acid and it is the immediate precursor of heme [16].

The toxic effect of PP-IX could probably be due to the imbalance of the redox systems in the over production of ROS [17][18]which leads to an increase in lipid peroxidation, which in turn is the main cause of damage to the liver [19][20]. In contrast, half life was reduced in the Sod deficient strain; these crhces provide information that PP-IX can act as an antioxidant and as a pro-oxidant [22].

Based on these previous works, the aim of the present study was to evaluate the antimutagenic capacity of PP-IX against the genetic damage induced by CrO 3 VIan agent that induces genetic damage especially through ROS.

In order to test DNA damage, we performed the wing spot test [23] as follows: Oviposition was restricted to a 2 h period so as to obtain more homogeneous samples in the melnaogaster of individuals under test.

Distilled water was used for all solutions. At this time, aliquots of larvae from each pretreatment concentration of PP-IX were treated with 0. Experiments were carried out in triplicate for each pretreated PP-IX solution and for each treatment melanogasher CrO 3 solution.

All treatments were conducted in the dark. Melanogaater wings were examined to identify small single spots one or two cellslarge single spots more than two cells of either mwh or flrand mwh-flr twin spots.

Twin spots are the result of an interchange between the flr 3 and the centromere [23]. For a description of the mutants see Lindsley and Zimm [24]. All data for each group represent at least two experiments performed in triplicate. Melanlgaster evaluate toxicity melanogasfer the combined treatment of the different PP-IX concentrations, we selected the highest CrO 3 concentration 2.

Treatment with gamma rays: On completion of the pretreatment, larvae from each concentration were divided into two groups, one of each group was irradiated with 20 Gy gamma rays in a Transelektro LGI, Co irradiator with a dose rate of up to After irradiation, larvae were put into a plastic vial with hydrated medium formula All the vials were introduced into a culture room until the development concluded.

The wings analysis was done as described earlier. Table 1 shows the frequency of all kinds of spots induced by the different concentrations of CrO 3. Statistical significant differences were found for all kinds of spots from 0. Noticeably, the higher concentration provoked a frequency of mutation that represents 20 times the frequency found in the control group. Table 2 includes the results obtained with the pretreatment of 0. Sections 1, 2, and 3, respectively.

Comparison of the action of PP-IX alone indicated that only 69 mM doubled the basal mutation frequency. The comparisons were between each group: The signs indicated in the PP-IX concentration alone are the results from comparisons with the negative control.

The statistical analysis comparing the combined treatments with their respective positive control in Table 1 indicated that pretreatment with 0. A statistically significant reduction was found from PP-IX 0. Pretreatment with PP-IX 6.

The analysis showed that PP-IX was nontoxic at the three concentrations tested compared to the control. CrO 3 was toxic at 2 and 2. Table 4 presents the results obtained for somatic mutation when larvae were pretreated with different concentrations of PP-IX and then treated with 20 Gy of gamma rays.

The results indicated that PP-IX in all tested concentrations had no effect on damage induced by gamma rays.


Although the mechanisms involved are not yet very clear, all DNA alterations can cause chronic degenerative diseases, including cancer [26]. Genetic damage induced by chromium is mainly produced as a result of its ability to induce free radicals, especially during the reduction from Cr [VI] to Cr [III].

Furthermore, exogenous antioxidants such as vitamins may reduce the cellular damage caused by free radicals. The main subject of the present study was to evaluate the antioxidant capacity of PP-IX avoiding the genetic damage induced by CrO 3. There is evidence that the antioxidant action of this tetrapyrrol depends on its concentration [21][28][29].

The results obtained in our study provided evidence of this effect: PP-IX was not toxic by itself Table 3 and concentrations melaongaster 0. Moreover, the highest concentration 69 mM proved to be mutagenic and induced damage comparable with 0. In agreement with this, PP-IX has been proven to induce oxidative stress [21] via production of superoxide ions and more efficiently of singlet oxygen in organic solutions [30]. Our results are in accord with this finding.

However, the evidence found in this study indicated that in organisms pretreated with PP-IX and subsequently treated with CrO 3the frequency of genetic damage was reduced in most of the treated groups.

Worth noting is the effect of the lowest concentration of PP-IX, 0. However, this increase could suggest a synergistic effect of CrO 3 plus the pro-oxidant action of PP-IX for its accumulation generating superoxide, as suggested by Afonso et al.

PP-IX reacts with molecular oxygen-producing peroxide radicals that cause lipid peroxidation and lead to different cell damage such as structural changes in the cell membrane, damage to proteins, inactivation of receptors, enzymes, and ion channels, all of which drrosophila lead to cell death [32]. Other studies have demonstrated that porphyrins can bind to DNA via a specific insertion within only one strand of DNA, i. In this way, these extra-helical structural elements could be a factor in certain pathways of mutagenesis [21].

The fact that the lowest concentration of PP-IX provoked a significant decrease me,anogaster damage could be due to the fact that the porphyrin ring could make complexes or act as a chelator, introducing the chromium into the ring.

PP-IX has been reported to be able to bind other metals such as zinc and nickel [36]. The different studies on the role of ferrochelatase have revealed that this enzyme catalyzes zinc as well as the iron chelating activity of protoporphyrin [14]. Ferrochelatase is known to catalyze insertion of divalent crruces metal ions other than iron in vitromost notably zinc, but cobalt, nickel, and copper have also each been reported to act as substrates, although species-specific differences have been noted [37][38][39].

Ferrochelatase could participate in the chelating chromium, provoking a reduction in its mutagenic effect. The work performed by Pimentel et al. The studies performed by Afonso et al.

Drosophila Genetics Simulation

In contrast, Cruces et al. Results from the melqnogaster work showed evidence indicating that the lower concentration of PP-IX reduced genetic damage of the radiomimetic agent CrO 3.

To evaluate the ability of PP-IX as a radical scavenger, we tested its action against the effect of 20 Gy of gamma rays Table 4. The comparison of the effect of PP-IX against the two agents revealed that the action of PP-IX is more likely to be preferable through the formation of chemical complexes with chromium rather than through decreasing reactive oxygen species. These findings placed PP-IX as an effective antimutagen at low doses. The work was supported by a grant No.

Available online 16 October National Center for Biotechnology InformationU. Journal List Toxicol Rep v. Published online Oct Author information Article notes Melznogaster and License information Disclaimer.

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