A new study published today in Frontiers in Immunology found that THC reduced multiple markers of inflammation and dampened neuroinflammatory signaling in experiments involving human immune cells and mice.
The study, conducted by researchers at the University of California, Los Angeles, examined how delta-9-tetrahydrocannabinol, or THC, affects immune responses triggered by lipopolysaccharide, a bacterial endotoxin commonly used to model inflammation.
According to the study, THC “markedly suppressed” inflammatory activity in THP-1 monocytic cells, a type of human immune cell line. Researchers found that THC reduced pro-inflammatory cytokines including IL-1β and TNF-α, while also suppressing interferon-stimulated genes associated with immune activation.
The researchers then tested the findings in primary human monocytes. There, THC significantly reduced expression of activation markers CD80, CD83 and CD209, which are associated with inflammatory immune responses.
To assess whether those effects extended beyond cell cultures, the researchers also used a mouse model of systemic inflammation. Mice were given either a control diet or a THC-supplemented diet for 15 days, with inflammation induced during the final three days through lipopolysaccharide injections.
In those mice, THC reduced activation of splenic myeloid cells and T cells, indicating a broader dampening of immune activation. Researchers also performed RNA sequencing on brain tissue and found reduced expression of neuroinflammatory pathways in mice exposed to THC.
At the same time, the study found enrichment of pathways associated with neurogenesis and synaptic plasticity, suggesting THC not only reduced inflammatory signaling in the brain but also promoted gene activity tied to neuronal maintenance and adaptability.
In the study’s discussion, the researchers said their findings show THC exerts “broad and context-dependent immunomodulatory effects” across cellular and animal models of inflammation. They concluded that THC modulates stress-adaptation pathways while suppressing excessive inflammatory and interferon responses.
The authors said the findings warrant further investigation into THC’s therapeutic potential in inflammatory and neurodegenerative diseases.
Although the results were positive, the study was preclinical and does not demonstrate that THC can safely or effectively treat inflammation-related conditions in humans. Still, because the research incorporated both human immune cells and an in vivo animal model, it provides a more detailed look at how THC may influence immune and brain-related inflammatory processes.
The study is titled Delta-9-tetrahydrocannabinol alleviates inflammation by modulating immune responses in LPS-induced murine inflammation model.
