Cannabidiol (CBD) helps protect brain cells from damage caused by methamphetamine, according to a study published in the International Journal of Molecular Sciences.

Researchers from Kunming Medical University examined the effects of CBD on primary hippocampal neurons exposed to methamphetamine. The hippocampus is a region of the brain involved in memory, learning and emotional regulation.

Methamphetamine exposure reduced the viability of the neurons and disrupted autophagy, the process cells use to remove damaged components and recycle materials. Although autophagy normally protects cells, excessive or incomplete autophagy can cause cellular damage when waste materials are not properly broken down.

Treatment with CBD at concentrations ranging from 1 to 10 micromolar reversed the methamphetamine-induced changes, improved neuronal viability and restored more normal autophagy activity.

Researchers found that CBD’s protective effects involved the serotonin 5-HT1A receptor and a related cellular signaling pathway known as the AC/cAMP/PKA/CREB pathway. Methamphetamine reduced 5-HT1A receptor activity while excessively activating the signaling pathway.

CBD restored 5-HT1A activity and suppressed the pathway’s excessive activation. A drug that activates the 5-HT1A receptor strengthened CBD’s effects, while a drug that blocks the receptor eliminated them.

The findings indicate that CBD acted as an allosteric modulator of the 5-HT1A receptor, meaning it influenced the receptor’s activity without directly activating it in the same way as a traditional receptor agonist.

Researchers concluded that CBD may have therapeutic potential for methamphetamine-related neurotoxicity by regulating autophagy and protecting neurons from cellular damage.

However, the study was conducted using isolated brain cells rather than animals or humans, and additional research is needed to determine whether the effects translate to clinical treatment.