Selected endocrine disrupting compounds (Vinclozolin, Flutamide, Ketoconazole and Dicofol): Effects on survival, occurrence of males, growth, molting and reproduction of Daphnia magna
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Background, Aim and Scope
Pollution-induced endocrine disruption in vertebrates and invertebrates is a worldwide environmental problem, but relatively little is known about effects of endocrine disrupting compounds (EDCs) in planktonic crustaceans (including Daphnia magna). Aims of the present study were to investigate acute 48 h toxicity and sub-chronic (4–6 days) and chronic (21 days) effects of selected EDCs in D. magna. We have investigated both traditional endpoints as well as other parameters such as sex determination, maturation, molting or embryogenesis in order to evaluate the sensitivity and possible use of these endpoints in ecological risk assessment.
Materials and Methods
We have studied effects of four model EDCs (vinclozolin, flutamide, ketoconazole and dicofol) on D. magna using (i) an acute 48 h immobilization assay, (ii) a sub-chronic, 4–6 day assay evaluating development and the sex ratio of neonates, and (iii) a chronic, 21 day assay studying number of neonates, sex of neonates, molting frequency, day of maturation and the growth of maternal organisms.
Acute EC50 values in the 48 h immobilization test were as follows (mg/L): dicofol 0.2, ketoconazole 1.5, flutamide 2.7, vinclozolin >3. Short-term, 4–6 day assays with sublethal concentrations showed that the sex ratio in Daphnia was modulated by vinclozolin (decreased number of neonate males at 1 mg/L) and dicofol (increase in males at 0.1 mg/L). Flutamide (up to 1 mg/L) had no effect on the sex of neonates, but inhibited embryonic development at certain stages during chronic assay, resulting in abortions. Ketoconazole had no significant effects on the studied processes up to 1 mg/L.
Sex ratio modulations by some chemicals (vinclozolin and dicofol) corresponded to the known action of these compounds in vertebrates (i.e. anti-androgenicity and anti-oestrogenicity, respectively). Our study revealed that some chemicals known to affect steroid-regulated processes in vertebrates can also affect sublethal endpoints (e.g. embryonic sex determination and/or reproduction) in invertebrates such as D. magna.
A series of model vertebrate endocrine disrupters affected various sub-chronic and chronic parameters in D. magna including several endpoints that have not been previously studied in detail (such as sex determination in neonates, embryogenesis, molting and maturation). Evaluations of traditional reproduction parameters (obtained from the 21 day chronic assay) as well as the results from a rapid, 4–6 day, sub-chronic assay provide complementary information on non-lethal effects of suspected organic endocrine disrupters.
Recommendations and Perspectives
It seems that there are analogies between vertebrates and invertebrates in toxicity mechanisms and in vivo effects of endocrine disruptors. However, general physiological status of organisms may also indirectly affect endpoints that are traditionally considered ‘hormone regulated’ (especially at higher effective concentrations as observed in this study) and these factors should be carefully considered. Further research of D. magna physiology and comparative studies with various EDCs will help to understand mechanisms of action as well as ecological risks of EDCs in the environment.
KeywordsDaphnia magna dicofol endocrine disruption flutamide ketoconazole sex determination vinclozolin
- Basler A, Lebsanft J (1999): Endocrine disrupters — Status and regulatory aspects. Env Sci Pollut Res 6, 44–48Google Scholar
- Finney D (1971): Probit analysis. Cambridge University, Cambridge, UKGoogle Scholar
- Gray L, Lambright C, Mann P, Price M, Cooper R, Ostby J (1999): Administration of potentially antiandrogenic pesticides (procymidone, linuron, iprodione, chlozolinate, p,p′-DDE, and ketoconazole) and toxic substances (dibutyl-and diethylhexyl phthalate, PCB 169, and ethane dimethane sulphonate) during sexual differentiation produces diverse profiles of reproductive malformations in the male rat. Toxicol Ind Health 15, 94–118CrossRefGoogle Scholar
- Heckman W, Kane B, Pakyz R, Cosentino M (1992): The effect of ketoconazole on endocrine and reproductive parameters in malemice and rats. J Androl 13, 191–198Google Scholar
- Kashian D (2004): Toxaphene detoxification and acclimation in Daphnia magna: do cytochrome P-450 enzymes play a role? Comp Biochem Phys C 137, 53–63Google Scholar
- Keiter S, Rastall A, Kosmehl T, Wurm K, Erdinger L, Braunbeck T, Hollert H (2006): Ecotoxicological assessment of sediment, suspended matter and water samples in the upper Danube River — A pilot study in search for the causes for the decline of fish catches. Env Sci Pollut Res 13, 308–319CrossRefGoogle Scholar
- OECD (1996): Organization for Economic Cooperation and Development — Guideline 202, Daphnia sp., Acute Immobilisation Test and Reproduction TestGoogle Scholar
- Olmstead A, LeBlanc G (2003): Insecticidal juvenile hormone analogs stimulate the production of male offspring in the crustacean Daphnia magna. Environ Health Perspect 111, 919–924Google Scholar
- Sanchez P, Alonso C, Fernandez C, Vega M, Garcia M, Tarazona J (2005): Evaluation of a multi-species test system for assessing acute and chronic toxicity of sediments and water to aquatic invertebrates — Effects of pentachlorophenol on Daphnia magna and Chironomus prasinus. J Soils Sediments 5, 53–58CrossRefGoogle Scholar
- Schurmeyer T, Nieschlag E (1984): Effect of ketoconazole and other imidazole fungicides on testosterone biosynthesis. Acta Endocrinologica 105, 275–280Google Scholar
- StahlschmidtAllner P, Allner B, Rombke J, Knacker T (1997): Endocrine disruptors in the aquatic environment. Env Sci Pollut Res 4, 155–162Google Scholar
- Subramonian T (2000): Crustacean ecdysteroids and embryogenesis. Comp Biochem Phys C 125, 135–156Google Scholar