Applications of Slime Mold: The Use of Physarum polycephalum as an Alternative Clinical Trial Subject for Over-the-counter Drugs

Globally, approximately 110 million lab animals die every year in clinical testing or from extermination post-experimentation (Diaz et al.). This issue has been debated and discussed in many areas of the medical and veterinary world. Along with this, prices to maintain live testing animals present financial burdens in research. An idea for a solution was the use of a unicellular organism known as slime mold between the in vitro and in vivo testing stages. While the name is misleading, slime mold is not a fungus. It is a form of protist. This protist has been documented in prior research navigating mazes, redesigning roads, along with learning and retaining information (Walecki). Based on these mind-boggling findings, an experiment was conducted to use the slime mold Physarum polycephalum as an addition to the clinical trial process. Four different solutions of water with dissolved over-the-counter drugs (Acetaminophen, Diphenhydramine, Dextromethorphan, and Caffeine) were tested on different samples of slime mold via their sustenance (oats), along with a positive control of water. The results collected over one week with a time-lapse camera indicated that the slime mold had different reactions to each of the four drugs used. It was proven that slime mold reacted as follows: Acetaminophen- attracted to the treatment and lingered on it; Diphenhydramine- attracted to the treatment and lingered; Dextromethorphan- attracted to the treatment and lingered; Caffeine the negative control- responded negatively as intended, eventually repelling the treatment; and water the positive control- responded positively as intended. In addition, the slime mold samples expressed different growth patterns seemingly out of randomness. These preliminary findings confirm that slime mold does react to over-the-counter drugs, as proven by observing the direct reaction to a substance over time. Therefore, with further research, slime mold could be a viable option for clinical trials, reducing subsequent animal deaths and research costs.