Comparative Transcriptomics of Broad-Spectrum and Synthetic Cannabidiol Treated Skeletal Myotubes
Cannabidiol (CBD), a cannabinoid from the cannabis plant, is widely used in sports for recovery, pain management, and sleep improvement, yet its effects on muscle are not well understood. This study aimed to determine the transcriptional response of murine skeletal muscle myotubes to broad-spectrum CBD and synthetic CBD (sCBD), hypothesizing significant changes in metabolism, myogenesis, and inflammation, with unique gene expression profiles for broad-spectrum CBD due to its additional compounds. Differentiated C2C12 myotubes were treated with 10 µM CBD, sCBD, or vehicle control (DMSO) for 24 hours before RNA extraction. Poly-A tail enriched mRNA libraries were constructed and sequenced using 2x50 bp paired-end sequencing.  CBD and sCBD treatment induced 4489 and 1979 differentially expressed genes (DEGs; p <0.001, FDR step-up <0.05), respectively, with common upregulation of 857 genes and common downregulation of 648 genes. Common upregulated DEGs were associated with “response to unfolded protein”, “cell redox homeostasis”, “endoplasmic reticulum stress”, “oxidative stress” and “cellular response to hypoxia”. Common downregulated DEGs were linked to “sarcomere organization”, “skeletal muscle tissue development”, “regulation of muscle contraction”, “skeletal muscle contraction” and “muscle contraction”. CBD treatment induced 1342 unique upregulated DEGs and 1137 unique downregulated DEGs, compared to 154 and 152 unique up- and downregulated DEGs in sCBD.  The transcriptional data indicate that CBD may induce mild cellular stress, activating pathways associated with altered redox balance, unfolded protein response, and endoplasmic reticulum stress. We hypothesize that CBD interacts with muscle and may elicit a 'mitohormetic' effect that warrants further investigation. Overall design: Our aim was to investigate the global transcriptional response of C2C12 skeletal muscle myotubes following exposure to broad-spectrum CBD and synthetic CBD. We aimed to ascertain if 1) skeletal muscle is responsive to broad spectrum CBD and synthetic CBD and 2) whether these effects are attributable solely to CBD or the vast array of other compounds in commercially available broad-spectrum CBD. We therefore exposed C2C12 myotubes to a vehicle control (DMSO), 10uM broad spectrum CBD or 10uM synthetic CBD for 24 hours.