The Effect of Caffeine and Ethanol on Flatworm Regeneration.

Flatworms, or planarian, have a high potential for regeneration and have been used as a model to investigate regeneration and stem cell biology for over a century. Chemicals, temperature, and seasonal factors can influence planarian regeneration. Caffeine and ethanol are two widely used drugs and their effect on flatworm regeneration was evaluated in this experiment. Non-toxic levels of caffeine, a stimulant, and ethanol, a depressant, were determined. The tails of the flatworms were removed and the regeneration stage was analyzed every 3 days for 15 days to see the effect of these drugs alone and in combination on regeneration. For day 3 and day 6, there was a significant difference between the ethanol treatment and the other treatments (positive control, caffeine treatment, and combined treatment). The ethanol treatment showed a delay in the initiation of regeneration but caught up to the other treatments by day 15