Effect of stannous chloride combined with caffeine on fecundity of Drosophila prosaltans

SHORT COMMUNICATION

EFFECT OF STANNOUS CHLORIDE COMBINED WITH CAFFEINE ON FECUNDITY OF DROSOPHILA PROSALTANS

Mary Massumi Itoyama and Hermione Elly Melara de Campos Bicudo

Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas de São José do Rio Preto, Universidade Estadual “Júlio de Mesquita Filho” - UNESP, 15054-000 São José do Rio Preto, SP, Brasil. Send correspondence to H.E.M.C.B.

ABSTRACT

The present study analyzed the number of progeny of stannous chloride- and/or caffeine-treated Drosophila prosaltans. A significant decreasing effect was observed in every case when compared to the control, except for the smallest stannous chloride dose used. Combinations of both substances using two different stannous chloride doses did not differ significantly from each other but number of progeny decreased 15% with the higher concentration combination when compared with caffeine-treated flies. The present results and data in the literature indicate that the effects of continuous ingestion of stannous chloride should be studied.

INTRODUCTION

Several studies have considered the sum effect of caffeine and other agents affecting DNA, such as X-rays (Mendelson and Sobels, 1974), gama-rays (Targa, 1983), UV radiation (Cremer et al., 1983), or substances such as the alkylating agent Thiotepa (Kilhman et al., 1982), tumorigenic drugs (Granberg-Ohman et al., 1980) and benzamide (Das, 1987). In some cases caffeine has shown a potentiating effect on mutagenic agents.

In this study we analyzed fecundity of Drosophila prosaltans treated with caffeine combined with stannous chloride (SnCl₂). In a previous study, in the same species, caffeine alone induced a dose-dependent fecundity decrease (Itoyama and Bicudo, 1992).

Mutagenic effects of caffeine were studied in prokaryotic as well as eukaryotic organisms with variable results, but in several cases it was considered a DNA repair inhibitor (Mendelson and Sobels, 1974; MacPhee and Leyden, 1985; Sasaki et al., 1989). Contradictory results were obtained for stannous chloride, in some cases showing genotoxic activity, causing changes in Escherichia coli DNA (Cunha et al., 1991) and decreasing SOS response in the same organism (Olivier and Marzin, 1987). In Drosophila melanogaster (Tripathy et al., 1990) and Saccharomyces cerevisiae (Singh, 1983), toxicity was observed but no mutagenic effect seemed to occur. Other studies on E. coli indicated induction of SOS response by treatment with SnCl₂ (Bernardo-Filho et al., 1994) and involvement of exonuclease III in repairing lesions caused by SnCl₂ (Cabral et al., 1998). Increasing doses of SnCl₂ were also observed to strongly reduce surviving of E. coli cells (Cabral et al., 1998). Thus, if SnCl₂ affects DNA and elicits DNA repair inhibited by caffeine, greater impairment might be expected from their ingestion together than separately.

Caffeine is largely consumed in coffee, teas and medicines (Benowitz, 1990) while stannous chloride, a powerful reducing agent, is used in radiopharmacy to synthesize scintigraphic tracers employed in nuclear medicine. The food industry uses it as a preservative (e.g., in soft drinks) and in some fluoride tooth pastes. Possible joint consumption of these drugs, therefore, makes relevant information on their effect, isolated or in interaction, even with other organisms used as indicators.

MATERIAL AND METHODS

Drosophila prosaltans (saltans group, saltans subgroup) is maintained in our laboratory at 20^o ± 1^oC, in banana-agar culture medium. The strain used is from Sangre Grande, Trinidad. Six-day-old virgin males and females were mass crossed (10 couples per vial) in bottles containing banana-agar culture medium (control experiments) or containing this culture medium with caffeine added (2,000 mg/ml; experiment named t₄) or with stannous chloride (500 mg/ml or 2,000 mg/ml; experiments named Sn₁ and Sn₂, respectively) or with both substances (t₄ + Sn₁ and t₄ + Sn₂). Six bottles were prepared for each type of medium. Flies were transferred once to new food of the same type, after five days. Parents were discarded five days later. Progeny were computed separately by sex.

Caffeine used was Cafeina Anidra, P.A. (1,3,7-trimethylxanthine), Reagen, Quimibrás, Indústrias Químicas S.A., Brazil. Stannous chloride (SnCl₂. H₂O) was Baker analyzed Reagent, Química Moura Brasil, S.A., Brazil.

For statistical purposes, exploratory data analysis, variance analysis for transformed data (square root) and linear model adjustment were used (Neter and Wasserman, 1974; Peres and Saldiva, 1983).

RESULTS AND DISCUSSION

Fly fecundity in the six experiments is in Table I. Because the numbers of males and females did not differ significantly from each other in the progeny of every experiment, only the total progeny numbers are presented. ANOVA (analysis of variance) applied to the transformed data showed significant values (F = 58,36; P £ 0.05). Multiple comparisons of Tukey (Table II) showed significant differences in comparisons of control experiment with every other experiment except that in which 500 mg/ml of stannous chloride was used alone. Both mixtures of substances (t₄ + Sn₁ and t₄ + Sn₂) differed significantly from Sn₁ and Sn₂ but not from t₄. Combined treatments also did not differ. Besides, results using the two doses of stannous chloride did not differ significantly from each other.

Administered isolatedly, caffeine as well as stannous chloride in a 2,000 mg/ml concentration of culture medium decreased fly fecundity significantly. As mentioned, for caffeine this had already been shown by Itoyama and Bicudo (1992) and Itoyama et al. (1998). However, when the flies were fed stannous chloride and caffeine combined, fecundity decrease did not differ significantly from flies fed caffeine alone. Nor did results differ when, combined with caffeine, stannous chloride in the doses of 500 mg/ml and 2,000 mg/ml was used, indicating that its effects were not cumulative with those of caffeine in decreasing fecundity when jointly administered. However, considering progeny number, there was a decrease of about 15% between t₄ + Sn₁ or t₄ + Sn₂ and t₄ (caffeine alone), suggesting that some additional toxic effect of stannous chloride cannot be completely discarded. Between Sn₁ and Sn₂, there was a decrease of about 10%. Thus, the present results in Drosophila prosaltans and the other data in literature, previously mentioned, recommend for further study continuous ingestion of stannous chloride.

ACKNOWLEDGMENTS

We thank Antonio José Manzato for assisting with the statistical analysis. M.M.I. is the recipient of fellowships from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brasil) and Coordenadoria de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES). Publication supported by FAPESP.

RESUMO

A fecundidade de Drosophila prosaltans foi analisada em indivíduos tratados com íon estanoso, cafeína ou íon estanoso, em duas concentrações, combinado com cafeína. Em todos os casos, a fecundidade foi significativamente menor quando comparada com o controle, exceto na menor concentração de íon estanoso. Nas combinações das duas substâncias, a redução não foi significativamente maior que a causada pela cafeína sozinha, podendo indicar que o efeito das duas substâncias juntas corresponde ao próprio efeito da cafeína separada. Mas a redução da fecundidade foi 15% maior no tratamento que utilizou íon estanoso em maior concentração, sugerindo que seu efeito tóxico nesse parâmetro, mesmo em combinação com a cafeína, não deve ser desconsiderado.

(Received May 3, 1999)

References

• Benowitz, N.L. (1990). Clinical pharmacology of caffeine. Annu. Ver. Med. 41: 277-288.
• Bernardo-Filho, M., Gutfilen, B. and Souza-Maciel, O. (1994). Effect of different anticoagulants on the labeling of red blood cells and plasma protein with ^99mTc. Nucl. Med. Commun. 15: 730-734.
• Cabral, R.E.C., Leităo, A.C., Lage, C., Caldeira-de-Araújo, A., Bernardo-Filho, F.L.S., and Cabral-Neto, J.B. (1998). Mutational potentiality of stannous chloride: an important reducing agent in the Tc-99m radiopharmaceuticals. DNA repair. Elsevier Science, Amsterdă.
• Cremer, C., Cremer, T., Hens, L., Baumann, H., Cornelis, J.J. and Nakanishi, K. (1983). UV micro-irradiation of the Chinese hamster cell nucleus and caffeine post-treatment. Immunocytochemical localization of DNA photolesions in cells with partial and generalized chromosome shattering. Mutat. Res. 107: 465-476.
• Cunha, M.C., Oliveira, E.F., Guillobel, H.C.B., Bernardo-Filho, M. and Alcântara-Gomes, R. (1991). Íon estanoso: um agente genotóxico. Livro de Resumos do I Simpósio Latino-Americano de Mutagęnese Ambiental (ALAMCTA), Caxambú, MG, p. 29.
• Das, S.K. (1987). Further evidence for a different mode of action of caffeine and benzamide on mammalian cells. Mutat. Res. 192: 69-74.
• Granberg-Ohman, I., Johansson, S. and Hjerpe, A. (1980). Sister-chromatid exchanges and chromosomal aberrations in rats treated with phenacetin, phenazone and caffeine. Mutat. Res. 79: 13-18.
• Itoyama, M.M. and Bicudo, H.E.M.C. (1992). Effects of caffeine on fecundity, egg laying capacity, development time and longevity in Drosophila prosaltans. Rev. Bras. Genet. 15: 303-321.
• Itoyama, M.M., Bicudo, H.E.M.C. and Manzato, A.J. (1998). The development of resistance to caffeine in Drosophila prosaltans: productivity and longevity after ten generations of treatment. Cytobios 96: 81-93.
• Kilhman, B.A., Hansson, K. and Anderson, H.C. (1982). The effects of post-treatments with caffeine during S and G₂ on the frequencies of chromosomal aberrations induced by Thiotepa in root of Vicia faba and in human lymphocytes in vitro. Mutat. Res. 104: 232-330.
• MacPhee, D.G. and Leyden, M.F. (1985). Effects of caffeine on ultraviolet-induced base-repair substitution and frameshift mutagenesis in Salmonella. Mutat. Res. 143: 1-3.
• Mendelson, D. and Sobels, F. (1974). The inhibiting effect of caffeine on the maternal repair of radiation-induced chromosome breaks in Drosophila. Mutat. Res. 26: 123-128.
• Neter, J. and Wasserman, W. (1974). Applied Linear Statistical Models. Richard D. Irwin, Inc., Homewood, IL.
• Olivier, P. and Marzin, D. (1987). Study of the genotoxic potential of 48 inorganic derivatives with the SOS chromotest. Mutat. Res. 198: 263-269.
• Peres, C.A. and Saldiva, C.D. (1983). Planejamento de experimentos. 5^o Simpósio Nacional de Probabilidade e Estatítica, 23 a 30 de julho de 1982, IME, USP, Săo Paulo, p. 98.
• Sasaki, Y.F., Imanishi, H., Ohta, T. and Shirasu, Y. (1989). Modifying effects of components of plant essence on the induction of sister-chromatid exchanges in cultured Chinese hamster ovary cells. Mutat. Res. 226: 103-110.
• Singh, I. (1983). Induction of reverse mutation and mitotic gene conversion by some metal compounds in Saccharomyces cerevisiae. Mutat. Res. 117: 149-152.
• Targa, H.J. (1983). Synergism between caffeine and g-radiation in the induction of dominant lethal mutations in oocytes and spermatozoa of Musca domestica. Mutat. Res. 110: 311-325.
• Tripathy, N.K., Wurgler, F.E. and Frei, H. (1990). Genetic toxicity of six carcinogens and six non-carcinogens in the Drosophila wing spot test. Mutat. Res. 242: 169-180.

Publication Dates

• Publication in this collection
  25 Aug 2000
• Date of issue
  Mar 2000

History

• Received
  03 May 1999