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.
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).”