Risk assessment of 4-Chloromethcathinone using Saccharomyces cerevisiae as a toxicological model

Abstract

Introduction: Novel psychoactive substances (NPS) have been rising on the street market as a legal alternative to controlled drugs of abuse, due to its chemical similarities. Synthetic cathinones are a NPS group that mimes cathinone, which is present in Khat plant, and has a similar effect to amphetamines [1]. 4-Chloromethcathinone (4-CMC) is a synthetic cathinone. Since 4-CMC does not have any scientific publications regarding its toxicity and mode of action, it is assumed that it has similar mechanisms to cathinone [2]. The aim of this work was to select a strain of S. cerevisiae which was sensitive to 4-CMC.

Materials and methods: 4-CMC was obtained as a research chemical via online. In order to select the most sensitive strain to 4-CMC, three different strains of S. cerevisiae (SC006 BY4741WT, SC166 BY4741ΔPDR5 and SC0111 AD1-8) grew in its presence. The concentration range of 4-CMC used were 0 to 75 mM for BY4741WT and BY4741ΔPDR5 and 0 to 44 mM for SC0111 AD1-8.

Results: Figure 1 shows growth curves of SC006, BY4741 WT, SC0166 BY4741ΔPDR5 and SC0111 AD1-8 strains in the presence of different concentrations of 4-CMC, monitored at O.D.600 nm. Analysis of growth curves allowed to obtain IC₅₀. These values were 63.8mM for SC006 BY4741 WT, 37.57mM for SC0166 BY4741ΔPDR5 and 15.02 mM for SC0111 AD1-8.

Figure 1. Growing kinetics of S. cerevisiae’s cells, for the strains SC006 BY4741WT (A), SC166 BY4741ΔPDR5 (B) and SC0111 AD1-8 (C), in the presence of several concentrations of 4-CMC.

Discussion and conclusions: Analysis of IC₅₀ values obtained suggests that SC0111 AD1-8 is the most sensitive strain in this study. SC0111 AD1-8 is a strain were all MDR genes are deleted. These genes are responsible to code ABC transporters which in turn play a role in the efflux of xenobiotics. The lower IC₅₀ value for SC0111 AD1-8 shows that ABC transporters have an important role in the excretion of 4-CMC.

Acknowledgements

The authors acknowledge funding from Egas Moniz – Cooperativa de Ensino Superior.