Toxicity Assay of Methanolic Extract of Caryota No Seed using Drosophila melanogaster Model

Objectives: To investigate the effect of methanolic extract of Caryota no (CN) seeds in Drosophila melanogaster (DM) survival and life span.

Study Design: Experimental design.

Place and Duration: African Centre of Excellence for Phytomedicine Research and Development, University of Jos, Jos Plateau State Nigeria between June 2018 and February 2019.

Methods: The LC50 was determined by exposing 50 flies to concentrations ranging from 1 mg to 600 mg per 10 g diet and mortality of flies was scored every 24 hours for 14 days and from the results, five doses were chosen for the next assay. Survival assays were carried out by exposing 50 flies in each vial to the following concentrations: 300 mg, 350 mg, 400 mg, 500 mg and 600 mg of methanolic extract in 5 replicates for 28 days with daily recording of mortality while the longevity assay continued from the survival until the last fly dies. All three experiments were done as three independent trials.

Results: The LC50 values of the methanolic extract was determined to be 6.533e+017 mg/10g food in D. melanogaster. The result of the survival assay with methanolic extract of CN showed slight significant (P < .05) increase with the lowest two doses but no significant (P > .05) difference with other higher doses compared to the control. The longevity assay revealed that the extract significantly (P < .05) decreased longevity in Drosophila melanogaster.

Conclusion: The results obtained from evaluating the methanolic extract of Caryota no indicate that the plant is relatively non-toxic and maybe safe under acute and subacute exposures but may become deleterious during chronic exposure.