Hyperthermia Increases Neurotoxicity Associated with Novel Methcathinones

Area of Science:

• Neuroscience
• Toxicology
• Cell Biology

Background:

• Hyperthermia is a severe adverse effect of recreational methcathinone use.
• The impact of hyperthermia on methcathinone-induced neurotoxicity is not well understood.

Purpose of the Study:

• To investigate the effects of hyperthermia (40.5 °C) on the neurotoxicity of methcathinone (MC), 4-chloromethcathinone (4-CMC), and 4-methylmethcathinone (4-MMC) in SH-SY5Y cells.

Main Methods:

• Exposure of SH-SY5Y cells to MC, 4-CMC, and 4-MMC under normothermic (37 °C) and hyperthermic (40.5 °C) conditions.
• Assessment of cytotoxicity via cellular ATP levels and plasma membrane damage.
• Evaluation of mitochondrial function, reactive oxygen species (ROS) production, heat shock protein (Hsp70) expression, and autophagy.

Main Results:

• 4-CMC and 4-MMC induced cytotoxicity, which was more pronounced at 40.5 °C.
• These compounds impaired mitochondrial electron transport chain function and increased ROS production, effects amplified by hyperthermia.
• Hyperthermia induced Hsp70 expression and stimulated autophagy, but these protective mechanisms only partially mitigated cell death.

Conclusions:

• Hyperthermia potentiates the neurotoxic effects of methcathinones on SH-SY5Y cells.
• Increased sensitivity to toxicants and exacerbated mitochondrial dysfunction contribute to enhanced neurotoxicity under hyperthermic conditions.
• Understanding these mechanisms is crucial for addressing the clinical consequences of methcathinone neurotoxicity.