Nvolvement of histamine H2 3-Hydroxyphenylacetic acid Biological Activity receptor in histaminedependent itch is not convincing6. TRPV1a nonselective cation channel stimulated by capsaicin, heat, and Hhas been implicated in mediation of pain and itch8,9. The TRPV1 channel is modulated by GPCR signalings10. Most pruritogens can activate GPCRs and trigger itch by activating the TRP channels, such as TRPV19. A expanding physique of proof indicates that H1R is coupled with Gq/G11 to active phospholipase C 3 (PLC 3), resulting within the boost of intracellular Ca2 in DRG neurons via TRPV111. Histamine also activates TRPV1 by means of the PLA2/LO pathway, top N-Acetyl-L-tryptophan custom synthesis towards the excitation of sensory neurons to induce itch12. In addition, TRPV1/ mice showed considerably attenuated scratching behavior immediately after injection of trypsin13. These findings recommend that TRPV1 plays a essential role in histaminedependent itch, especially in H1 receptormediated itch. Cnidii monnieri fructus (dried fruit of Cnidium monnieri [L.] Cusson), as an herbal medicine, functions in antiallergic, antidermatophytic, anticancer, killing parasites, and in antiitch14. Cnidium monnieri fructus has been used for centuries in traditional Chinese medicine to treat numerous ailments such as sexual dysfunction, asthma, osteoporosis, and skin ailments15. The main constituents of Cnidium monnieri are coumarins, for example osthole, imperatorin, bergapten, isopimpinellin, and xanthotoxin, which have various biologicalCollege of Basic Medicine, Nanjing University of Chinese Medicine, 138 XianLin Road, Nanjing 210023, China. Jishou University, Jishou, 410023, China. 3College of Life Science, Nanjing Regular University, Nanjing, 210046, China. 4College of Basic Medicine, Guangxi University of Chinese Medicine, 13 WuHe Road, Nanning 530299, China. 5 The Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine (TCM) Prevention and Therapy of Tumor, China. These authors contributed equally to this work. Correspondence and requests for supplies must be addressed to G.Y.W. (email: [email protected]) or Z.X.T. (email: [email protected])2Received: 23 September 2015 accepted: 21 April 2016 Published: 10 MayScientific RepoRts | 6:25657 | DOI: 10.1038/srepwww.nature.com/scientificreports/Figure 1. Chemical structure of osthole.activities16. It has been reported that osthole (7methoxy8 sopentenoxycoumarin, Fig. 1) has antiinflammatory, antiosteoporotic, antitumor, and estrogenlike effects171. Osthole also has an antipruritic effect in allergic model animals22. Matsuda, H. et al. reported that ethanol extract of Cnidii Monnieri Fructus which includes osthole showed an inhibitory effect on compound 48/80induced scratching behavior23. The precise role of osthole inside the histaminedependent itch, having said that, is unclear as well as the molecular mechanism of its antipruritic impact is underappreciated. Inside the present study, we sought to discover regardless of whether osthole inhibits histaminedependent itch by means of TRPV1. Our results showed that osthole clearly decreased the scratching behaviors induced by histamine. Osthole also suppressed the H1 and H4 receptormediated scratching behaviors. Furthermore, osthole decreased the response of DRG neurons to histamine, HTMT, VUF8430, and capsaicin by modulating the TRPV1 activity. A previous study reported that a high dose of histamine can induce apparent scratching behavior24. To examine the antipruritic effect with the osthole on the histaminedependent itch, a pretreatment by subcutaneous injection with osthole (ten nM, 30 M, 50 l/site).