Papers by Emilio Pimentel
Journal of Investigative Dermatology, May 1, 2000
Mutation Research Letters, Nov 1, 1991
Journal of Toxicology and Environmental Health, Part A
Environmental Toxicology and Pharmacology
This is an open access article. Unrestricted non-commercial use is permitted provided the origina... more This is an open access article. Unrestricted non-commercial use is permitted provided the original work is properly cited. Open Access Full open access to this and thousands of other papers at
Superficies y Vacío, 2019
Organic nanoparticles of bifenthrin (agricultural insecticide) were successfully synthesized by t... more Organic nanoparticles of bifenthrin (agricultural insecticide) were successfully synthesized by the laser ablation of solids in liquids (LASL) technique, using as liquid medium a solution of a polymeric surfactant at 0.1 %. The results showed that the use of the surfactant improves the stability of the organic nanoparticles 18 times as compared to those synthesized in water. The characterization by UV-Vis spectroscopy allowed evaluating the stability of colloids, as well as determining the concentration of nanoparticles in the medium. In the characterization by TEM and HRTEM was possible to observe nanoparticles with the most probable size of 5 nm and interplanar distances which correspond to the crystalline structure of the starting material. Mass coupled gas chromatography technique was used to corroborate the chemical composition of nanoparticles. Results of biological tests using Drosophila Melanogaster fly, showed that the use of the nanostructured compound is effective in lowe...
International Journal of Radiation Biology, 2020
Purpose: Evaluation of genetic risk in germ cells is still matter of research, mainly due to thei... more Purpose: Evaluation of genetic risk in germ cells is still matter of research, mainly due to their role in the transmission of genetic information from one generation to another. Although numerous experiments have been carried out in Drosophila in order to study the effect of radiation on germ cells, the role of dose rate (DR) has not been fully explored. The purpose of this study was to evaluate the action of DR on the radioprotection induction on male germ cell of D. melanogaster. Material and method: The productivity and the sex-linked recessive lethal (SLRL) tests were used to evaluate the radio-sensitivity of different states of the germ line of males. Two-day old males of CantonS wild type strain were pre-treated with 0.2 Gy at 5.4 or 34.3 Gy/h of gamma rays from a 60 Co source, three hours later, they were irradiated with 20 Gy at 907.7 Gy/h. Thereafter, each single male was crossed with 3 five-day old Basc virgin females, that were replaced every other day by new females. This procedure was conducted three times, to test the whole germ cell stages. Results: Females crossed with males irradiated with 0.2 Gy at both DR tested, laid a higher number of eggs than control, but egg-viability was reduced. On the other hand, in the group of 0.2 Gy + 20 Gy-combined treatments-, the total number of eggs laid, decreased only when 0.2 Gy were delivered at 34.3 Gy/h however, the egg-viability increased. The dose of 0.2 Gy at both DR did not modify the baseline frequency of SLRL. A tendency to decrease in the frequency of lethals in brood III was found in combined treatments at both DR. Conclusion: The fact that 0.2 Gy at 5.4 or 34.3 Gy/h induced an increase in the eggviability and a tendency to decrease the genetic damage in pre-meiotic cells provoked by 20 Gy, might indicate the induction of any mechanism that could be interpreted as radioprotection in male germ cells of D. melanogaster. Results emphasize the need to carry out more studies on the effect of the DR on the induction of genetic damage in germ cells.
Environmental Toxicology and Pharmacology, 2018
The present study evaluates whether the protective effect of live yeast (LY) against direct and i... more The present study evaluates whether the protective effect of live yeast (LY) against direct and indirect mutagenic agents, persists in the offspring from individuals fed with LY. The wing-spot test in Drosophila was used; four different mates were performed: a) neither females nor males were fed with LY-enriched food (NLYxNLY); b) only females were fed (LYxNLY); c) males were fed (NLYxLY) or d) both progenitors were fed (LYxLY). Results confirm that LY strongly stimulates fecundity in females but not in males and provides strength to the egg for survive. A greater reduction in mutation rate was observed when females were feed, in the following relationship: LYxNLY > LYxLY > NLYxLY. No protection was found against action in any of the promutagens tested. Results suggest that LY has a very powerful antimutagenic action, predominantly against the action of ionizing radiation and Chromium trioxide that can be transmitted mainly through the female.
Materials Research Express, 2019
Journal of Toxicology and Environmental Health, Part A, 2019
The role of dose rate (DR) on biological effects of ionizing radiation is an area of significant ... more The role of dose rate (DR) on biological effects of ionizing radiation is an area of significant research focus and relevant to environmental exposures. The present investigation was aimed to examine the direct relationship between viability and genotoxicity in Drosophila melanogaster, induced by gamma rays in a range of doses from 2 to 35 Gy administered at three different DR. Results indicated that larval-adult viability was reduced in relation to dose but not DR. No marked differences were found in the LD 50 produced by differing DR tested. Frequencies of somatic mutation and recombination increased in direct correlation with dose and DR. Data demonstrate the importance of determination of the relationship between viability and genotoxicity induced by DR in in vivo systems for toxicological and radioprotection studies.
Environmental toxicology and pharmacology, 2018
Many studies have revealed that ascorbic acid (Aa) acts as a powerful inhibitor of genetic damage... more Many studies have revealed that ascorbic acid (Aa) acts as a powerful inhibitor of genetic damage. The objetive of the present study was to evaluate the radioprotector effect of Aa at two diferent radiation dose rates. The somatic mutation and recombination test in Drosophila melanogaster was used. 48 h larvae were treated for 24 h with 25, 50 and 100 mM of Aa. After pretreatment, larvae were irradiated with 20 Gy of gamma rays administered at 36 or 960 Gy/h. Toxicity, development rate and frequency of mutant spots were recorded. Results provide evidence of a radioprotective effect for all tested concentrations of Aa only when 20 Gy were delivered at 36 Gy/h and only with 25 mM using the 960 Gy/h. To consider the use of Aa as radioprotector or therapeutic agent, it is necessary to know its potential under different situations to avoid unwanted injuries.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1997
Graf et al. (U. Graf, F.E. Würgler, A.J. Katz, H. Frei, H. Juon, C.B. Hall, P.G. Kale, Somatic mu... more Graf et al. (U. Graf, F.E. Würgler, A.J. Katz, H. Frei, H. Juon, C.B. Hall, P.G. Kale, Somatic mutation and recombination test in Drosophila, Environment Mutagen. 6 (1984) 153-188.) described the overall results of assays of a series of compounds in the Drosophila wing spot test as indicating that single mwh spots appeared most frequently, followed by less frequent twin spots with both mwh and flr cells and lastly the 'quite rare' single flr spots. Data are presented below demonstrating that some compounds behave in a manner consistent with the above description, whereas others do not in that the frequency of single flr spots is equal to or exceeds that of twin spots and cannot be described as occurring 'rarely'. It is suggested that (large) flr singles be used as a measure of mutations/deletions directly from treated transheterozygotes. An argument is presented questioning the use of treated mwh +/+ TM3 individuals as an assay of mutations/deletions at the mwh+ locus.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1996
Larvae of Drosophila were exposed to a range of concentrations of alpha particles from 3 to 318 m... more Larvae of Drosophila were exposed to a range of concentrations of alpha particles from 3 to 318 mRad. and genetic effects measured in the wing-spot test. The results were positive, and evidence of a linear relationship between exposure and response observed. The induction of chromosome breakage is suggested by the significantly higher frequency of twin spots in the treated series compared with controls.
Open Journal of Animal Sciences, 2013
Protoporphyirin-IX (PP-IX) is a precursor of the biosynthesis of the hemo group, most of the cyto... more Protoporphyirin-IX (PP-IX) is a precursor of the biosynthesis of the hemo group, most of the cytochromes and the chlorophylls. The PP-IX is used for medical purposes, and recently a report indicated that it exhibits a dual action since it can decrease or increase the genetic damage caused by N-nitroso-N-ethylurea (ENU) in somatic cells of Drosophila. PP-IX is known to be able to act as an anti-or pro-oxidant agent. The aim of the present research was to study the role of PP-IX on the lifespan of Drosophila melanogaster, taking into account the fact that increasing levels of ROS can accelerate the aging process. The CantonS strain (CS) was used as well as Sod and Cat which are deficient in the endogenous enzymes, superoxide dismutase and catalase, respectively. Groups of females and males were treated separately with 5 mg/ml of PP-IX solution. The comparison of survival curves indicates that this pigment extended the lifespan of CS. In contrast, Sod strain showed that the opposite effect and had no effect in Cat strain. The fact that PP-IX reduces the mean lifespan in Sod deficient strain might suggest a pro-oxidant action of PP-IX, and consequently the cumulating of ROS as a superoxide could have a mutagenic effect as was shown recently. The results presented evidence of the dual effect of PP-IX.
Radiation Measurements, 2003
Uncertainties exist on the extrapolation of induction radiation damage curves from high to low do... more Uncertainties exist on the extrapolation of induction radiation damage curves from high to low doses. This work presents experimental data on the e ects of low radon doses to Drosophila melanogaster. Larvae (48 h old) of D. melanogaster (Canton-S) were exposed during 72 h to nine di erent radon concentrations (6
Mutation Research/Environmental Mutagenesis and Related Subjects, 1990
Toxicology Reports, 2014
Several epidemiological studies have reported the relation between chromium exposure (used in dif... more 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. There is evidence that some tetrapyrrols such as protoporphyrin IX (PP-IX), a 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 hold larvae were pretreated for 24 h with 0, 0.69, 6.9, or 69 mM of PP-IX, after which groups of larvae were fed 0.025-2.5 mM CrO 3 solution in Drosophila instant medium. The results indicated that the lower PP-IX concentration (0.69 mM) significantly reduced the genetic damage induced by all CrO 3 concentrations tested. In contrast, 6.9 and 69 mM only inhibited the damage induced by CrO 3 2.5 mM. 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.
Food Factors for Cancer Prevention, 1997
Tests of the antimutagenic effect of sodium copper chlorophyllin (SCC) in the wing spot test in D... more Tests of the antimutagenic effect of sodium copper chlorophyllin (SCC) in the wing spot test in Drosophila are reviewed. The mutagens include gamma rays (γ-rays), chromium (VI) oxide (CrO3), ethylnitrosourea (ENU), cyclophosphamide (CPA), and methyl methanesulfonate (MMS). SCC gives evidence of being antimutagenic against the DNA-damaging effect of all these agents with the exception of CPA. Results of tests with ascorbic acid (a.a.) in combination with γ-rays and CrO3 proved positive.
Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 1999
By delaying the time of gamma irradiation of 72 h larvae, pretreated at 48 h with 5% chlorophylli... more By delaying the time of gamma irradiation of 72 h larvae, pretreated at 48 h with 5% chlorophyllin CHLN , it was established that the overall inhibiting effect of CHLN in somatic cells of Drosophila, as measured in the wing spot test, persists for about 4 days or until the time of cessation of the proliferation of wing anlagen. In the same population of cells, some spot classes gave evidence of an inhibitory effect whereas others did not arguing against the suggestion that the radioprotective effect of CHLN is a consequence of an induced delay in development, shrinking of the potential radiation target and lowering the probability of induced events. Other observations of interest are described.
Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2000
Irradiation of 96 h old Drosophila following a 24 h pretreatment with 5% chlorophyllin (CHLN) was... more Irradiation of 96 h old Drosophila following a 24 h pretreatment with 5% chlorophyllin (CHLN) was delayed 0-4 days. The antimutagenic effect of CHLN in somatic cells monitored by the wing spot test persisted for 3 days after completion of the pretreatment and appeared to terminate at a time corresponding to the cessation of mitotic divisions of wing anlagen cells. Within the same population of cells, CHLN demonstrated both an inhibitory effect as measured in mwh single spot classes, and contrarily, a promoting effect in the class of mwh/flr twin spots and to an extent in the class of large flr spots. The reason for the contrasting effects of CHLN remains to be determined.
Uploads
Papers by Emilio Pimentel