Background  Pursuing drugs that can treat and relieve the symptoms of sepsis has been an urgent clinical problem. Cannabidiol is promising to be used in the treatment of a variety of neurodegenerative diseases and immune-related diseases. Our research group focuses on the treatment of sepsis by cannabidiol.

  Objective  To observe the effects of cannabidiol (CBD) on the survival rate, inflammatory cytokine levels (IL-1b, IFN-γ, TNF-α and IL-6), lung pathological changes and immune cell infiltration in sepsis mice.

  Methods  This experiment was divided into two parts, with 72 mice in total. The first part was the survival rate observation experiment, and the second part was the specimen collection experiment. Thirty-six mice were selected in the first experiment and randomly divided into model control group, solvent control group and cannabidiol experimental group, with 12 mice in each group. At 12 h, 24 h, 36 h, 48 h, 60 h, and 72 h after CLP, 1 mL of 0.9% sodium chloride aqueous solution, cannabidiol solvent or 20 mg/kg CBD solution was intraperitoneally injected. The survival rate of 72 h after cecal ligation and perforation was observed. The remaining 36 mice were included in the second experiment and grouped according to the above scheme, and 1 mL of 0.9% sodium chloride aqueous solution, solvent or 20 mg/kg CBD solution was intraperitoneally injected at 12 h, 24 h, and 36 h after CLP. The mice were sacrificed at 48 h after CLP, the levels of inflammatory cytokines (IL-1b, IFN-γ, TNF-α and IL-6), lung pathological changes and liver immune cell infiltration were detected.

  Results  Compared with the model control group and the solvent control group, the cytokine levels of IL-1b, IFN-γ, TNF-α and IL-6 in the CBD experimental group decreased significantly (all P＜0.01). The accumulation of CD4 ⁺ T, CD8 ⁺ T cells and natural killer cells in the septic liver were reduced, thus improving the lung pathological damage. The 72 h survival rate of mice in the model control group, solvent control group and CBD experimental group was 16.7%, 25% and 58.3% respectively.

  Conclusion  The above results indicate that CBD can reduce lung injury in mice with sepsis, inhibit the secretion of inflammatory cytokines, reduce immune cell infiltration and prolong the survival of septic mice.