title: The effects of synthetic cannabidiol on skeletal muscle development in vitro
Creators: name: Cole, P
Publisher: name: Liverpool John Moores University
Year: 2022

description: Cannabidiol (CBD) is a non-intoxicating cannabinoid derived from the Cannabis sativa plant. CBD is becoming an increasingly popular treatment for several clinical conditions and in pain management. Consequently, this has attracted the attention of both clinical and non-clinical populations, including athletes. As of 2018, CBD is no longer prohibited by the World Anti Doping Agency (WADA) as it doesn’t represent an actual or potential health risk to athletes and evades violating the spirit of sport, two of the criteria any substance must satisfy to be prohibited for use by WADA. Due to this, there has been an exponential increase in the usage of CBD products by athletes, however, little is still known about its potential benefits in this population. One major issue that arises with athletes using CBD is products which state they are free from any other cannabinoids, including THC, often still contain high concentrations of THC, with the urinary threshold for THC at 150 ng/ml , thus resulting in an Anti-Doping Rule Violation (ADRV). This is where synthetic cannabidiol (sCBD) may be a favourable alternative use to CBD for athletes. sCBD is an active pharmaceutical ingredient that is chemically identical to the naturally produced hemp-derived CBD without any other cannabinoids or chemicals present, therefore theoretically it should possess similar properties. This thesis aimed to investigate the effects of synthetic cannabidiol on skeletal muscle development and growth by treating murine C2C12 muscle cells with varying doses of sCBD at different stages of myogenesis to assess cell viability and myotube morphology. The main findings from this work suggest that high concentrations of sCBD are not tolerated by C2C12 cells and cause cell death in both myoblasts and myotubes. Preliminary findings demonstrated higher doses of sCBD at 50 μM (P = &lt;0.0001) and 20 μM (P = &lt;0.0008) are detrimental to myoblast health as metabolic activity was reduced and cell viability was reduced at 50 μM (P = &lt;0.0363) after 48-hours. Following 10 days of serum withdrawal to induce differentiation in the presence or absence of differing concentrations of sCBD, metabolic activity was significantly reduced at 50 μM (P = &lt;0.0001), 20 μM (P = &lt;0.0001) and 10 μM (P = &lt;0.0001) with reduced cell viability reported at 50 μM (P = &lt;0.0486) and 20 μM (P = &lt;0.0302). On the other hand, following acute treatment, where myotubes were treated with differing concentrations of sCBD at terminal differentiation, significant reductions in metabolic activity were only reported at 50 μM (P = &lt;0.0045). Significant changes in myotube morphology were only observed after a repeated treatment of sCBD, however, a decrease in nuclear fusion index (NFI) following acute dosing was also recorded. In conclusion, this thesis provides preliminary data on the effects of sCBD on skeletal muscle myogenesis in vitro. Our findings indicate that higher doses of sCBD are detrimental to muscle cell health both during proliferation and differentiation, with greater negative effects reported after chronic treatment of sCBD. Athletes should avoid supplementing with CBD/sCBD due to WADA’s unclear stance on synthetic and other natural cannabinoids, as well as the alleged detrimental effects.