On the way to elucidate the effects of cannabidiol (CBD) on living organisms - assessment of changes in the global transcription profile of the hippocampus in a mouse model

Cannabidiol (CBD) is a phytocannabinoid that has anti-inflammatory, immunomodulatory, antioxidant, anxiolytic, antipsychotic, and anticonvulsant effects. This study aims to examine the effects of CBD on behavior, immune system activity, and stress levels, and to determine its impact on transcriptomic alterations in selected mouse organs. Male mice of the standard C57BL/6J strain were used. The animals were classified into two groups - (I) short-term CBD administration (2 days) and (II) long-term CBD administration (28 days). In each of the main groups, there were three subgroups receiving different doses of CBD - from low, commonly used in supplementation (0.2 mg/kg bw), through medium (10 mg/kg bw), to high, used in some clinical trials (20 mg/kg bw). Additionally, a control group (placebo/vehicle) was maintained in each of the main groups. Chemically pure Cannabidiol (CBD) was administered intraperitoneally (in the research group) to ensure that the substances reached the blood vessels of the digestive system. CBD was administered in a single daily dose. The mice were housed under standard conditions and with standard feeding and watering ad libitum. They were also tested daily (group I) or every third day (group II) to determine well-being and health. After the period of CBD administration, the mice were immediately euthanized and organs such as the brain (various brain structures including hippocampus), spleen, and liver were collected. In this part of the experiment, hippocampus samples were used to isolate total RNA. The recovered RNA was quality assessed and used to prepare directional libraries for high throughput transcriptome sequencing using CORALL mRNA-Seq V2 kit (Lexogen). The libraries were sequenced commercially in a 2x150bp paired-end run. The obtained sequence data were used to analyze the differential expression between the different CBD dosages and the control group. Differentially expressed genes were classified into particular processes or functions and were subjected to statistical testing for overrepresentation. The synthesis of the obtained data will allow the proposal of potential mechanisms of CBD action and create an atlas of changes taking place in the transcriptome of the main target organs.