Uncaria Rhynchophylla and hirsuteine as TRPV1 agonists inducing channel desensitization

Abstract

Ethnopharmacological relevance Uncaria rhynchophylla (UR) is recognized for its therapeutic applications in treating hypertension and inflammation. However, the specific molecular mechanisms how UR and its bioactive constituents modulate inflammatory pathways remain unknown. This study investigates the effects of UR extract and its constituent, hirsuteine (HST), on TRPV1 channel modulation which is related to hypertension and inflammation. Materials and methods Electrophysiological recordings and calcium imaging experiments were conducted to assess TRPV1 activation by UR extract and HST in HEK293T cells and sensory neurons. Results UR extract and HST activated TRPV1 in HEK293T cells, with repeated applications causing channel desensitization. HST application on TRPV1-positive sensory neurons significantly reduced electrical activity compared to capsaicin. Conclusion This study demonstrated UR extract and HST are a novel TRPV1 agonists inducing channel desensitization and a potent agent for treatment of TRPV1 dependent pain relief.