A Systematic Review of Delta-9-Tetrahydrocannabinol (∆9-THC) in Astrocytic Markers.

Background: Astrocytic reactivity in substance use disorders (SUDs) has been extensively studied, yet the molecular effect of delta-9-tetrahydrocannabinol (∆9-THC, the main psychoactive compound in cannabis) on glial cells, especially astrocytes, remains poorly understood. Exploring ∆9-THC's impact on astrocytic markers can provide insight into its effects on brain functions such as homeostasis, synaptic transmission, and response to neuronal injury. This systematic review synthesizes findings from studies investigating ∆9-THC's impact on astrocytic markers.

Methods: A systematic review was conducted using EMBASE, Medline, and PsychoInfo via the OvidSP platform. Studies reporting astrocytic markers following ∆9-THC exposure in animals and humans were included. Data were extracted from twelve eligible full-text articles, and the risk of bias was assessed using the Systematic Review Center for Laboratory Animal Experimentation.

Results: This research identified several astrocytic markers, including glial fibrillary acidic protein (GFAP), nestin, and glutamate-aspartate transporter (GLAST). Both GFAP and nestin expressions increased in adulthood following adolescence and adult ∆9-THC exposure. An increase in GLAST expression was also noted during early development after ∆9-THC exposure.

Conclusions: This review indicates varying levels of astrocytic reactivity to ∆9-THC across different developmental stages, including adolescence and adulthood. ∆9-THC appears to impact maturation, particularly during early developmental stages, and exhibits sex-dependent effects.