Sacharomyces cerevisiae as a screening tool to assess cathinones’ toxicity

Abstract

Introduction: Novel psychoactive substances (NPS) are sold on Internet under the appearance of herbal blends or bath salts as an alternative to cannabis, khat and ephedra. Synthetic cathinones are artificial mimetics of khat and like methamphetamine are indirect agonists of dopamine, serotonin and noradrenaline receptors [1]. Ninety-seven fatal cases of intoxication by ingestion of mephedrone (4-methylmethcathinone), one of the types of synthetic cathinone derivatives, were reported on literature since 2010 [2]. New synthetic cathinones emerges in the street market and internet on a regular base and the properties of this substances change regularly, due to modification on the molecules, to avoid legislation. This makes almost impossible to characterize synthetic cathinones toxicological profiles on a short time scale, mostly due to the typical time-consuming experimental assays. In here we propose the use of Saccharomyces cerevisiae, which has been proven an invaluable model to study the fundamental molecular mechanisms involved in several human diseases [3], growth curves in the presence of synthetic cathinones to get an indicative measure of its toxicity.

Materials and methods: BY4741 yeast cells were diluted to a standardized OD600 nm =2×10⁻³ (∼1.67×10-5 cells/mL) in YNB medium (Yeast Nitrogen Base w/o Amino Acids 0.67%, glucose 2%, required amino acids) and grown at 30 °C. Buphedrone was acquired from the best source available. The cytotoxic potential of synthetic cathinones was assessed by monitoring the growth of Saccharomyces cerevisiae BY4741 in the presence and absence of substances. Yeast growth curves (O.D.600nm versus growth time) were compared.

Results: Figure 1 shows that yeast growth in the presence of 75 mM cat is lower when compared to the growth curve in the absence of the substance. These preliminary results points that cathinones inhibits yeast growth.

Figure 1. Growth curves results in Saccharomyces cerevisiae BY4741 in the presence of 75 mM of buphedrone.

Discussion and conclusions: Saccharomyces cerevisiae has been used previously to test the toxicity of pharmacological drugs. Our results show that yeast is sensitive to cathinones suggesting that this system has potential to assess the possible toxicity of these legal highs. This rapid and inexpensive methodology may allow high throughput screening of cathinones’ toxicity, which might help the legislators to schedule NPS avoiding expected public health problems.

Acknowledgements

This study was funded by the project HOME/2014/JDRU/AG/DRUG/7086 from the European Comission.