CBD Reduced Some Immune Cells in Rats but Spared Natural Killer Cells
Repeated CBD treatment in rats reduced T cells, B cells, and total white blood cells at higher doses while sparing or enhancing natural killer (NK) and NKT cells involved in antiviral and antitumor immunity.
Quick Facts
What This Study Found
Male rats received daily CBD injections (2.5 or 5 mg/kg) for 14 days.
At the higher dose (5 mg/kg), CBD caused a significant decrease in total white blood cells and in the numbers of T cells, B cells, T helper cells, and T cytotoxic cells.
However, this immunosuppressive effect did not affect NK or NKT cells, which are responsible for nonspecific antiviral and antitumor immune responses.
At the lower dose (2.5 mg/kg), CBD actually increased NKT cell numbers and the percentage of NK cells.
The results suggest CBD may suppress adaptive (specific) immunity while sparing or enhancing innate (nonspecific) antiviral and antitumor defenses.
Key Numbers
Doses: 2.5 and 5 mg/kg daily for 14 days. At 5 mg/kg: significant decrease in total leukocytes, T cells, B cells, T helper, and T cytotoxic cells. NK and NKT cells were spared. At 2.5 mg/kg: NKT cells increased.
How They Did This
Fourteen-day repeated-dose animal study. Male Wistar rats received daily intraperitoneal CBD injections at 2.5 or 5 mg/kg or vehicle. Blood was collected one hour after the last injection. Three-color immunofluorescent staining was used to identify T, B, NK, NKT, T helper, and T cytotoxic lymphocyte subsets.
Why This Research Matters
Understanding how CBD affects different branches of the immune system is important for evaluating its potential in autoimmune conditions (where suppressing specific immunity could help) and in cancer (where preserving NK cell function is desirable).
The Bigger Picture
The selective immunomodulatory profile of CBD, suppressing adaptive immunity while sparing innate antitumor responses, could have implications for autoimmune diseases and cancer. However, translating animal immune findings to humans requires substantial caution.
What This Study Doesn't Tell Us
Rat immune systems differ from human immune systems. CBD was administered by injection, not orally. The doses and duration may not correspond to typical human CBD use. Blood sampling at a single time point may not capture the full immune response dynamics.
Questions This Raises
- ?Does oral CBD in humans produce similar selective immunomodulation?
- ?Could CBD be useful as an adjunct in autoimmune conditions?
- ?Would the preserved NK cell function translate to maintained antitumor immunity in CBD users?
Trust & Context
- Key Stat:
- CBD reduced adaptive immune cells while sparing or enhancing innate antiviral and antitumor NK cells
- Evidence Grade:
- Animal study with intraperitoneal CBD delivery. Immune effects in rats may not translate to humans taking oral CBD.
- Study Age:
- Published in 2009. CBD immunology research has expanded since then, though the selective immunomodulatory profile described here has been partially supported by later studies.
- Original Title:
- Cannabidiol-induced lymphopenia does not involve NKT and NK cells.
- Published In:
- Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 60 Suppl 3, 99-103 (2009)
- Authors:
- Ignatowska-Jankowska, B, Jankowski, M, Glac, W, Swiergel, A H
- Database ID:
- RTHC-00361
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Does CBD weaken the immune system?
This rat study found CBD reduced some immune cells (T cells, B cells) at higher doses but preserved or enhanced natural killer cells involved in antiviral and antitumor defense. Whether this occurs in humans at typical CBD doses is not established.
Could this be beneficial for autoimmune conditions?
Theoretically, reducing overactive adaptive immune responses while preserving innate immunity could be beneficial in autoimmune diseases, but this hypothesis has not been adequately tested in human clinical trials.
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Cite This Study
https://rethinkthc.com/research/RTHC-00361APA
Ignatowska-Jankowska, B; Jankowski, M; Glac, W; Swiergel, A H. (2009). Cannabidiol-induced lymphopenia does not involve NKT and NK cells.. Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 60 Suppl 3, 99-103.
MLA
Ignatowska-Jankowska, B, et al. "Cannabidiol-induced lymphopenia does not involve NKT and NK cells.." Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 2009.
RethinkTHC
RethinkTHC Research Database. "Cannabidiol-induced lymphopenia does not involve NKT and NK ..." RTHC-00361. Retrieved from https://rethinkthc.com/research/ignatowska-jankowska-2009-cannabidiolinduced-lymphopenia-does-not
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.