In vitro activity: Cyclobenzaprine is a 5-HT2 receptor antagonist and inhibitor, in some article, cyclobenzaprine hydrochloride was used as the compound to research in cyclobenzaprine. Cyclobenzaprine inhibits the enhancement of the monosynaptic reflex (MSR) induced by 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI). Cyclobenzaprine strongly binds to 5-HT2 receptors with a Ki value of 62 nM. Cyclobenzaprine binds to 5-HT1 receptor with a Ki value of 2900 nM.

Kinase Assay: Cyclobenzaprine Hcl is a skeletal muscle relaxant and a central nervous system (CNS) depressant. Target: 5-HT Receptor 2A Cyclobenzaprine is a skeletal muscle relaxant and a central nervous system (CNS) depressant. Cyclobenzaprine was thought to be an alpha 2-adrenoceptor agonist that reduced muscle tone by decreasing the activity of descending noradrenergic neurons. Cyclobenzaprine reduced the monosynaptic reflex amplitude dose dependently and this effect was not inhibited by the alpha 2-adrenoceptor antagonists idazoxan and yohimbine. Cyclobenzaprine-induced monosynaptic reflex depression was not attenuated by noradrenergic neuronal lesions produced by 6-hydroxydopamine. Cyclobenzaprine is a 5-HT2 receptor antagonist and that its muscle relaxant effect is due to inhibition of serotonergic, not noradrenergic, descending systems in the spinal cord .

Cell Assay: In 16 of 21 spontaneously active neurons, the administration of cyclobenzaprine at 1 mg/kg decreased the discharge rate of neurons, while two neurons showed no response and three neurons demonstrated an increased rate. The decrease amount varied widely but was always ≥ 25%. In three cases, the decrease amounts were 100%. In all cases, the cell response to cyclobenzaprine followed the MSR response very closely in time.