Bingpian is a time-honored herb in traditional Chinese medicine (TCM) and has been used for millennia in clinical applications in China. Natural bingpian is a resin obtained from Cinnamomum trees and is almost a pure chemical. Its chemical composition is (+)-borneol, which is a bicyclic monoterpene.

In TCM, topical application of bingpian is used to treat pain and swelling. However, few clinical studies that meet international quality standards have been performed to demonstrate bingpian’s clinical efficacy. Bngpian is currently approved by the U.S. FDA to be used as a flavoring substance or adjuvant in food but not as a clinical drug, but its underlying cellular and molecular mechanisms are unknown.

A team of scientists from the Kunming Institute of Zoology of Chinese Academy of Sciences and professional clinicians from Shanghai Changzheng Hospital recently examined the analgesic efficacy of topical bingpian in a randomized, double-blind, placebo-controlled clinical study involving 122 patients with postoperative pain. This work was published in EMBO Molecular Medicine.

Scientists found that topical application of bingpian led to significantly greater pain relief than placebo did. Using mouse models of pain, they identified the TRPM8 channel as the most sensitive molecular target of bingpian and showed that topical bingpian-induced analgesia was almost exclusively mediated by TRPM8 and involved a downstream glutamatergic mechanism in the spinal cord.

This study provided the first rigorous clinical evidence for the analgesic efficacy of topical bingpian in humans and elucidated its underlying mechanism, which may pave the way for the internationalization of bingpian and future development of new topical analgesics.

This work was supported by grants from Yunnan Provincial Science and Technology Department, National Key Basic Research Program of China and the National Natural Science Foundation of China.