The Potentials of Uncariae Ramulus Cum Uncis for the Treatment of Migraine: Targeting CGRP in the Trigeminovascular System

Migraine is a common chronic neurovascular disease characterized by headaches. Calcitonin gene-related peptide (CGRP) signaling in the trigeminovascular system plays a critical role in the development of migraine. The monoclonal antibodies against CGRP and its receptor have been used clinically for the prevention of migraine; however, they may not be a cost-effective option for patients with low-frequency episodic migraine. Thus, it is quite valuable to search for an alternative strategy to downregulate CGRP signaling. Uncariae Ramulus Cum Uncis (UR) has a longterm history for the treatment of cardiovascular and central nervous systems disorders in China and Eastern Asia. Several clinical studies showed that famous herbal formulas comprising UR were able to improve headaches in migraineurs. In addition, increasing in vivo studies further indicated that migraine-related changes, such as CGRP increase, inflammation, nitric oxide increase, and spontaneous behavior problems could be reduced by UR extraction and its active constituents. In this review, we summarize the pathophysiological factors affecting abnormal CGRP release in the trigeminovascular system during a migraine, and for the first time, analyze the effects of UR on these factors and evaluate the potentials of UR for the treatment of migraine.