Camellia japonica callus–derived extracellular vesicles attenuate αCGRP-induced endothelial hyperactivation via cAMP-dependent signaling

Menopausal vasomotor symptoms (VMS), such as hot flushes, are associated with neurovascular instability initiated by estrogen deficiency and characterized by excessive peripheral vasodilation. Calcitonin gene-related peptide (CGRP), a potent vasodilatory neuropeptide, plays a pivotal role by activating adenylyl cyclase-cAMP signaling in endothelial cells, thereby stimulating nitric oxide (NO) production and angiogenic activity. This study investigated whether Camellia japonica callus–derived extracellular vesicles (CJEV) can modulate αCGRP-induced endothelial activation relevant to the vascular component of VMS. In human microvascular endothelial cells (HMEC-1), αCGRP markedly increased proliferation, cAMP accumulation, NO synthesis, and angiogenic behaviors through activation of the AKT-mTOR and CREB pathways. CJEV treatment significantly attenuated these responses without cytotoxicity, reducing cAMP accumulation, eNOS phosphorylation, and CREB-dependent gene expression, including VEGFA , BCL2 , and MMP9 . Functionally, CJEV reduced endothelial migration and tube formation, indicating attenuation of αCGRP-driven angiogenic responses. Collectively, these findings identify CJEV as a modulator of αCGRP-responsive endothelial signaling and provide a mechanistic basis for further investigating plant-derived extracellular vesicles as regulators of αCGRP-associated vascular signaling relevant to vasomotor physiology.