Anti-Inflammatory Effects of Cannabigerol in Rheumatoid Arthritis Synovial Fibroblasts and Peripheral Blood Mononuclear Cell Cultures Are Partly Mediated by TRPA1


“Since its medical legalization, cannabis preparations containing the major phytocannabinoids (cannabidiol (CBD) and δ9-tetrahydrocannabinol (THC)) have been used by patients with rheumatoid arthritis (RA) to alleviate pain and inflammation. However, minor cannabinoids such as cannabigerol (CBG) also demonstrated anti-inflammatory properties, but due to the lack of studies, they are not widely used. CBG binds several cellular target proteins such as cannabinoid and α2-adrenergic receptors, but it also ligates several members of the transient potential receptor (TRP) family with TRPA1 being the main target. TRPA1 is not only involved in nnociception, but it also protects cells from apoptosis under oxidative stress conditions. Therefore, modulation of TRPA1 signaling by CBG might be used to modulate disease activity in RA as this autoimmune disease is accompanied by oxidative stress and subsequent activation of pro-inflammatory pathways. Rheumatoid synovial fibroblasts (RASF) were stimulated or not with tumor necrosis factor (TNF) for 72 h to induce TRPA1 protein. CBG increased intracellular calcium levels in TNF-stimulated RASF but not unstimulated RASF in a TRPA1-dependent manner. In addition, PoPo3 uptake, a surrogate marker for drug uptake, was enhanced by CBG. RASF cell viability, IL-6 and IL-8 production were decreased by CBG. In peripheral blood mononuclear cell cultures (PBMC) alone or together with RASF, CBG-modulated interleukin (IL)-6, IL-10, TNF and immunoglobulin M and G production which was dependent on activation stimulus (T cell-dependent or independent). However, effects on PBMCs were only partially mediated by TRPA1 as the antagonist A967079 did inhibit some but not all effects of CBG on cytokine production. In contrast, TRPA1 antagonism even enhanced the inhibitory effects of CBG on immunoglobulin production. CBG showed broad anti-inflammatory effects in isolated RASF, PBMC and PBMC/RASF co-cultures. As CBG is non-psychotropic, it might be used as add-on therapy in RA to reduce IL-6 and autoantibody levels.”

“Therefore, CBG might be suited as an adjunct therapy for RA to reduce cytokine and autoantibody production.”

Application of Oil-in-Water Cannabidiol Emulsion for the Treatment of Rheumatoid Arthritis

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“Introduction: Rheumatoid arthritis (RA) is a chronic autoimmune disease with unknown cause. It mainly affects joints and, without proper treatment, negatively impacts their movement, causes painful deformities, and reduces the patients’ quality of life. Current treatment options consist of various types of disease-modifying antirheumatic drugs (DMARDs), however 20-30% of patients are partially resistant to them. Therefore, development of new drugs is necessary. Possible option are compounds exhibiting their action via endocannabinoid system, which plays an important role in pain and inflammation modulation. One such compound – cannabidiol (CBD) has already been shown to attenuate synovitis in animal model of RA in in vivo studies. However, it has low bioavailability due to its low water solubility and lipophilicity. This issue can be addressed by preparation of a lipid containing formulation targeting lymphatic system, another route of absorption in the body. 

Materials and Methods: CBD-containing emulsion was prepared by high-shear homogenization and its droplet size distribution was analysed by optical microscopy. The relative oral bioavailability compared to oil solution as well as total availability of CBD were assessed in a cross-over study in rats and absorption of CBD via lymphatic system was observed. The effect of CBD on the animal model of RA was determined. 

Results: Compared to oil solution, the emulsion exhibited higher absolute oral bioavailability. Significant lymphatic transport of CBD was observed in all formulations and the concentrations in lymph were calculated. The therapeutic effect of CBD on RA was confirmed as an improvement in clinical symptoms as well as morphological signs of disease activity were observed during the study. 

Conclusion: In this work, we prepared a simple stable emulsion formulation, determined the pharmacokinetic parameters of CBD and calculated its absolute bioavailability in rats. Moreover, we successfully tested the pharmaceutical application of such a formulation and demonstrated the positive effect of CBD in an animal model of RA.”

Cannabidiol as a treatment for arthritis and joint pain: an exploratory cross-sectional study

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“Introduction: An estimated 54 million Americans currently suffer from debilitating arthritis. Patients who have exhausted conservative measures can be subject to chronic pain and resort to symptomatic management with anti-inflammatories, acetaminophen, and opioids. Cannabidiol (CBD) is a non-psychoactive cannabinoid that has shown promise in preclinical studies to reduce inflammation and pain associated with arthritis. The purpose of this study was to explore patient perceived effects of cannabidiol on symptoms of arthritis.

Methods: A novel anonymous questionnaire was created to evaluate perceived efficacy of cannabidiol for the treatment of arthritis. A self-selected convenience sample (N=428) was recruited through online methods including social media accounts and newsletters (The Arthritis Foundation and Savvy Cooperative) between May 5, 2020, and November 5, 2020. Statistical analysis was performed to determine differences between types of arthritis and improvements in quality-of-life symptoms. Furthermore, a regression analysis was performed to identify variables associated with decreasing or discontinuing other medications.

Results: CBD use was associated with improvements in pain (83%), physical function (66%), and sleep quality (66%). Subgroup analysis by diagnosis type (osteoarthritis, rheumatoid, or other autoimmune arthritis) found improvements among groups for physical function (P=0.013), favoring the osteoarthritis group. The overall cohort reported a 44% reduction in pain after CBD use (P<0.001). The osteoarthritis group had a greater percentage reduction (P=0.020) and point reduction (P<0.001) in pain compared to rheumatoid arthritis and other autoimmune arthritis. The majority of respondents reported a reduction or cessation of other medications after CBD use (N=259, 60.5%): reductions in anti-inflammatories (N=129, 31.1%), acetaminophen (N=78, 18.2%), opioids (N=36, 8.6%) and discontinuation of anti-inflammatories (N=76, 17.8%), acetaminophen (N=76, 17.8%), and opioids (N=81, 18.9%).

Conclusion: Clinicians and patients should be aware of the various alternative therapeutic options available to treat their symptoms of arthritis, especially in light of the increased accessibility to cannabidiol products. The present study found associations between CBD use and improvements in patient’s arthritis symptoms and reductions in other medications. Future research should focus on exploring the benefits of CBD use in this patient population with clinical trials.”

“The present study, while exploratory in nature, suggests there may be therapeutic benefits to CBD use and highlights the need for research in a field where the science lags behind popular use.”

Cannabidiol: Influence on B Cells, Peripheral Blood Mononuclear Cells, and Peripheral Blood Mononuclear Cell/Rheumatoid Arthritis Synovial Fibroblast Cocultures

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“Background: Cannabidiol (CBD), one major nonintoxicating phytocannabinoid from Cannabis sativa demonstrated anti-inflammatory effects in animal models of several inflammatory conditions, including arthritis. However, it is still unknown which cell types mediate these anti-inflammatory effects of CBD, and, since CBD binds to a plethora of receptors and enzymes, it is complicated to pinpoint its mechanism of action. In this study, we elucidate the effects of CBD on B cells and peripheral blood mononuclear cells (PBMCs) in respect to survival, calcium mobilization, drug uptake, and cytokine (IL-6, IL-10, and TNF) and immunoglobulin production. 

Methods: Modulation of intracellular calcium and drug uptake in B cells was determined by using the fluorescent dyes Cal-520 and PoPo3, respectively. Cytokine and immunoglobulin production was evaluated by enzyme-linked immunosorbent assay. PBMC composition and B cell survival after CBD treatment was assessed by flow cytometry. 

Results: B cells express two major target receptors for CBD, TRPV2 (transient receptor potential vanilloid 2) and TRPA1 (transient receptor potential ankyrin 1), which are not regulated by B cell activation. CBD increased intracellular calcium levels in mouse and human B cells, which was accompanied by enhanced uptake of PoPo3. These effects were not dependent on transient receptor potential channel activation. CBD increased the number of early apoptotic B cells at the expense of viable cells and diminished interleukin (IL)-10 and tumor necrosis factor (TNF) production when activated T cell independently. In PBMCs, CBD increased IL-10 production when B cells were activated T cell dependent, while decreasing TNF levels when activated T cell independently. In PBMC/rheumatoid synovial fibroblast cocultures, CBD reduced IL-10 production when B cells were activated T cell independently. Immunoglobulin M production was augmented by CBD when B cells were activated with CpG. 

Conclusion: CBD is able to provide pro- and anti-inflammatory effects in isolated B cells and PBMCs. This is dependent on the activating stimulus (T cell dependent or independent) and concentration of CBD. Therefore, CBD might be used to dampen B cell activity in autoimmune conditions such as rheumatoid arthritis, in which B cells are activated by specific autoantigens.”

Impact of Δ 9-Tetrahydrocannabinol on Rheumatoid Arthritis Synovial Fibroblasts Alone and in Co-Culture with Peripheral Blood Mononuclear Cells


“δ9-Tetrahydrocannabinol (THC) has demonstrated anti-inflammatory effects in animal models of arthritis, but its mechanism of action and cellular targets are still unclear. The purpose of this study is to elucidate the effects of THC (0.1-25 µM) on synovial fibroblasts from patients with rheumatoid arthritis (RASF) and peripheral blood mononuclear cells (PBMC) from healthy donors in respect to proliferation, calcium mobilization, drug uptake, cytokine and immunoglobulin production. Intracellular calcium and drug uptake were determined by fluorescent dyes Cal-520 and PoPo3, respectively. Cytokine and immunoglobulin production were evaluated by ELISA. Cannabinoid receptors 1 and 2 (CB1 and CB2) were detected by flow cytometry. RASF express CB1 and CB2 and the latter was increased by tumor necrosis factor (TNF). In RASF, THC (≥5 µM) increased intracellular calcium levels/PoPo3 uptake in a TRPA1-dependent manner and reduced interleukin-8 (IL-8) and matrix metalloprotease 3 (MMP-3) production at high concentrations (25 µM). Proliferation was slightly enhanced at intermediate THC concentrations (1-10 µM) but was completely abrogated at 25 µM. In PBMC alone, THC decreased interleukin-10 (IL-10) production and increased immunoglobulin G (IgG). In PBMC/RASF co-culture, THC decreased TNF production when cells were stimulated with interferon-γ (IFN-γ) or CpG. THC provides pro- and anti-inflammatory effects in RASF and PBMC. This is dependent on the activating stimulus and concentration of THC. Therefore, THC might be used to treat inflammation in RA but it might need titrating to determine the effective concentration.”

Anti-Inflammatory, Antioxidative, and Hepatoprotective Effects of Trans Δ9-Tetrahydrocannabinol/Sesame Oil on Adjuvant-Induced Arthritis in Rats


“Rheumatoid arthritis (RA) is a painful chronic autoimmune disease affecting the joints. Its first-line therapy, Methotrexate (MTX), although effective in ameliorating the progress of the disease, induces hepatotoxicity over long-term usage. Thus, seeking natural compounds with fewer side effects could be an alternative therapeutic approach. This study aimed to investigate the anti-inflammatory, antiarthritic, and antioxidative effects of synthetic trans-Δ9-tetrahydrocannabinol (Δ9-THC) dissolved in sesame oil (Dronabinol) against MTX in adjuvant-induced arthritis (AIA) rat model. Daily oral administration of Δ9-THC/sesame oil, over a period of 21 days, was well tolerated in arthritic rats with no particular psychoactive side effects. It markedly attenuated the severity of clinical manifestations, recovered the histopathological changes in tibiotarsal joints, and repressed the splenomegaly in arthritic rats. Δ9-THC/sesame oil therapy showed similar effects to MTX in neutralizing the inflammatory process of AIA, through attenuating erythrocyte sedimentation rate (ESR) scores and proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1β), and interleukin-6 (IL-6) levels, to normal values. As opposed to MTX, this natural combination markedly protected the liver of arthritic rats and downregulated the induced oxidative stress by increasing the antioxidant defense system such as activities of catalase and superoxide dismutase (SOD) and levels of glutathione (GSH). These results suggest promising effects for the clinical use of Δ9-THC/sesame oil therapy in alleviating arthritic clinical signs as well as arthritis-induced liver injury.”

“Dronabinol (Δ9-THC in sesame oil) is usually used to treat nausea and vomiting caused by chemotherapy or weight loss and loss of appetite in AIDS patients, yet, to the best of our knowledge, this is the first study that proves the antiarthritic and antioxidative effects of this combination in an experimental model of RA with a hepatoprotective effect against arthritis-induced liver injury compared to commonly used antirheumatic drug (MTX).”

The Effect of Medical Cannabis on Pain Level and Quality of Sleep among Rheumatology Clinic Outpatients

logo“Introduction: Medical cannabis (MC) is becoming increasingly popular for the treatment of chronic pain conditions.

In this study, we evaluated the effect of MC treatment on pain level and quality of sleep of patients with different medical conditions at the rheumatology clinic.

Conclusions: MC had a favorable effect on pain level and quality of sleep among all spectrums of problems at the rheumatology clinic.”

“MC has a favorable effect on pain level and sleep quality among nearly the entire spectrum of resistant “chronic pain syndromes” seen or referred to rheumatology clinics, including inflammatory diseases resistant to biological treatment, although the effect of MC on synovitis was relatively mild.

Cannabis should be seriously considered in every “chronic pain condition” whenever the accepted modalities of treatment are insufficient for alleviating patient’s pain and sleep problems.”

Cannabidiol (CBD): a killer for inflammatory rheumatoid arthritis synovial fibroblasts

 Cell Death & Disease“Cannabidiol (CBD) is a non-intoxicating phytocannabinoid from cannabis sativa that has demonstrated anti-inflammatory effects in several inflammatory conditions including arthritis.

In this study, we show that CBD increases intracellular calcium levels, reduces cell viability and IL-6/IL-8/MMP-3 production of rheumatoid arthritis synovial fibroblasts (RASF).

CBD reduced cell viability, proliferation, and IL-6/IL-8 production of RASF. Moreover, CBD increased intracellular calcium and uptake of the cationic viability dye PoPo3 in RASF, which was enhanced by pre-treatment with TNF.

Thus, CBD possesses anti-arthritic activity and might ameliorate arthritis via targeting synovial fibroblasts under inflammatory conditions.”

“In conclusion, CBD might be beneficial as an adjuvant treatment in rheumatoid arthritis that might support the action of currently used disease-modifying anti-rheumatic drugs.”


British Journal of Pharmacology “Δ9‐THCA‐A, the precursor of Δ9‐THC, is a non‐psychotropic phytocannabinoid that shows PPARγ agonistic activity. Herein, we investigated Δ9‐THCA ability to modulate classic cannabinoid receptors (CB1 and CB2) and evaluated its anti‐arthritis activity.

Experimental Approach

Cannabinoid receptors binding and intrinsic activity, as well as their downstream signaling were analyzed in vitro and in silico . The anti‐arthritis properties of Δ9‐THCA‐A were studied in human chondrocytes and in the murine model of collagen‐induced arthritis (CIA). Plasmatic disease biomarkers were identified by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) based on proteomic and ELISA assays.

Key Results

Functional and docking analyses showed that Δ9‐THCA‐A can act as an orthosteric CB1 agonist and also as a positive allosteric modulator in the presence of CP‐55,940. In addition, Δ9‐THCA‐A seemed to be an inverse agonist for CB2. In vivo experiments showed that Δ9‐THCA‐A reduced arthritis in CIA mice. Δ9‐THCA‐A prevented the infiltration of inflammatory cells; synovium hyperplasia and cartilage damage. Furthermore, Δ9‐THCA‐A inhibited the expression of inflammatory and catabolic genes on knee joints. The anti‐arthritic effect of Δ9‐THCA‐A was ablated by either SR141716 or T0070907. Analysis of plasmatic biomarkers as well as determination of cytokines and anti‐collagen antibodies confirmed that Δ9‐THCA‐A mediates its activity mainly through PPARγ and CB1 pathways.

Conclusion and Implications

Δ9‐THCA‐A modulates CB1 receptor through the orthosteric and allosteric binding sites. In addition, our studies document that Δ9‐THCA‐A exerts anti‐arthritis activity through CB1/PPARγ pathways, highlighting its potential for the treatment of chronic inflammatory diseases such as Rheumatoid Arthritis (RA).”

 British Pharmacological Society | Journals

Cannabidiol: A Brief Review of Its Therapeutic and Pharmacologic Efficacy in the Management of Joint Disease.

Cureus | LinkedIn“Cannabis use in the management of musculoskeletal diseases has gained advocacy since several states have legalized its recreational use.

Cannabidiol (CBD), a commercially available, non-neurotropic marijuana constituent, has shown promise in arthritic animal models by attenuating pro-inflammatory immune responses. Additional research has demonstrated the benefit of CBD in decreasing the endogenous pain response in mice subjected to acute arthritic conditions, and further studies have highlighted improved fracture healing following CBD use in murine mid-femoral fractures.

However, there is a lack of high-quality, novel research investigating the use of CBD in human musculoskeletal diseases aside from anecdotal accounts and retrospective reviews, perhaps due to legal ramifications limiting the enrollment of patients. The purpose of this review article is to highlight the extent of current research on CBD and its biochemical and pharmacologic efficacy in the treatment of joint disease, as well as the evidence for use of CBD and cannabis in patients undergoing joint arthroplasty.

Based on available literature relying on retrospective data and case reports, it is challenging to propose a recommendation for CBD use in perioperative pain management. Additionally, a number of CBD products currently available as supplements with different methods of administration, and it is important to remember that these products are non-pharmaceuticals. However, given the increased social relevance of CBD and cannabis-based medicines, future, prospective controlled studies evaluating their efficacy are needed.”