Effects of Hemp Seed Oil and Cannabidiol on Behavior and Inflammation in Depression Model Mice

Objective: To explore the effects of hemp seed oil and Cannabidiol (CBD) on the behavior and inflammatory factors of chronic unpredictable mild stress (CUMS) mice. Methods: 50 male C57BL/6 mice were randomly divided into 5 groups: Blank group, model group, hemp seed oil group (3 mL/kg), CBD low-dose (15 mg/kg), CBD high-dose group (30 mg/kg), and gavage was continued for 8 weeks. The expression of depression, anxiety, learning and cognitive ability and inflammatory factors (tumor necrosis factor (TNF-α), interleukin-1 (IL-1β) and induced NOS (iNos)) were measured in mice. Results: Compared with the blank group, the model group had significant differences in depression and anxiety behavior and learning and cognitive functions (P<0.05; P<0.01); compared with the model group, the CBD dose group significantly improved the model mice from the depressive and anxious behavior of mice to the cognitive function of learning (P<0.05; P<0.01); besides, the hemp seed oil group significantly improved the sucrose preference index and new object recognition ability in mice (P<0.05). Compared with the blank group, the expression of TNF-α, IL-1β and iNos mRNA in the cortex and hippocampus of the model group significantly increased (P<0.05; P<0.01); compared with the model group, CBD dose groups showed that the expression of TNF-α, IL-1β and iNos mRNA in the cortex and hippocampus significantly decreased (P<0.05; P<0.01); There was no significant difference in TNF-α and iNos in cortex and hippocampus of the hemp seed oil group(P>0.05). The results of immunohistochemistry showed that hemp seed oil and CBD both inhibited the expression of ionized calcium-binding adaptor molecule 1 (IBA-1) of inflammatory mediator microglia. Conclusion: CUMS mice are successfully modeled. Hemp oil can partially improve the depressive behavior and cognitive ability of mice and reduce the expression of IL-1β. The CBD can improve the anxiety symptoms of mice, increase learning and cognitive functions, and inhibit the cortex and hippocampus of brain tissue. The inflammatory response of hemp seed oil and CBD has a certain effect on CUMS model mice.