EXPERIMENTAL APPROACH: We tested the ability of THCV to activate CB(2) receptors by determining whether: (i) it inhibited forskolin-stimulated cyclic AMP production by Chinese hamster ovary (CHO) cells transfected with human CB(2) (hCB(2)) receptors; (ii) it stimulated [(35)S]GTPgammaS binding to hCB(2) CHO cell and mouse spleen membranes; (iii) it attenuated signs of inflammation/hyperalgesia induced in mouse hind paws by intraplantar injection of carrageenan or formalin; and (iv) any such anti-inflammatory or anti-hyperalgesic effects were blocked by a CB(1) or CB(2) receptor antagonist.
KEY RESULTS: THCV inhibited cyclic AMP production by hCB(2) CHO cells (EC(50)= 38 nM), but not by hCB(1) or untransfected CHO cells or by hCB(2) CHO cells pre-incubated with pertussis toxin (100 ng.mL(-1)) and stimulated [(35)S]GTPgammaS binding to hCB(2) CHO and mouse spleen membranes. THCV (0.3 or 1 mg.kg(-1) i.p.) decreased carrageenan-induced oedema in a manner that seemed to be CB(2) receptor-mediated and suppressed carrageenan-induced hyperalgesia. THCV (i.p.) also decreased pain behaviour in phase 2 of the formalin test at 1 mg.kg(-1), and in both phases of this test at 5 mg.kg(-1); these effects of THCV appeared to be CB(1) and CB(2) receptor mediated.
CONCLUSIONS AND IMPLICATIONS: THCV can activate CB(2) receptors in vitro and decrease signs of inflammation and inflammatory pain in mice partly via CB(1) and/or CB(2) receptor activation.
- CHO Cells
- Cell Line, Transformed
- Cyclic AMP
- Dose-Response Relationship, Drug
- Guanosine 5'-O-(3-Thiotriphosphate)
- Mice, Inbred C57BL
- Pain Measurement
- Receptor, Cannabinoid, CB1
- Receptor, Cannabinoid, CB2