Preliminary mortality and eclosion: dose-determining factors of aqueous extract of Hibiscus sabdariffa in Drosophila melanogaster

Povzetek

Background: This study investigated the toxicity of Hibiscus sabdariffa extract using simple end point assays (mortality and eclosion assay) in Drosophila melanogaster (Harwich strain) flies. Methods: The study was carried out in two phases (phases I and II) and in an array of concentrations of 10, 20, 30, 40 and 50 mg/ml in phase I; 100, 250, 500, 750 and 1000mg/ml in phase II for the period of 168 hours. Thirty (30) 4-day old flies were used in each concentration and mortality was recorded every 24 hours for the period of the study. Eclosion was scored after emergence of the adult flies. Results: There was no significant difference (p<0.05) in mortality and eclosion between the (experimental) concentrations and the control in the first phase of this study, indicating low/zero toxicity to the parent and the emerged flies. However, higher concentrations of 250 through 1000mg/ml of the second phase showed significant (p<0.05) increased mortality and decreased eclosion scores, indicating high acute toxicity to D. melanogaster. Conclusion: The LC50 of Hibiscus sabdariffa after 168 hours was 427.1mg/10g diet in Drosophila melanogaster and much eclosion was recorded at doses between 10 - 100mg/10g diet as compared with doses between 250 - 1000mg/10g diet. Eclosion can be considered a factor in the determination of LC50 in Drosophila melanogaster.