Background: Pain is one of the most common clinical symptoms . This
review aims to describe research on herbs and their active ingredients in treating pain
and provide a valuable reference for the development and utilization of analgesic
traditional Chinese medicine (TCM).
Material and Methods: The literature search was performed from 1995 to October
2016, covering the relevant studies that concern the treatment of pain with TCM. Active
ingredients extracted from TCM with analgesic activity are summarized and classified
into six categories, including polysaccharides, saponins, alkaloids, flavonoids,
terpenoids, and other constituents.
Results: There are two pathways constituting the analgesic mechanisms of TCM:
through the central nervous system and the peripheral nervous system. The former
pathway includes increasing the content of endogenous analgesic substances like
opiate peptide, cutting down the second messenger of neurotransmitter like nitric oxide
(NO), reducing the content of prostaglandin E2 (PGE2) in brain tissues, blocking the
central calcium channel, reducing excitatory amino acids in brain tissues, inhibiting their
receptors and raising the content of the central 5-hydroxytryptamine (5-HT). The latter
one usually involves the decrease in the secretion of peripheral algogenic substances,
the induction of pain-sensitive substances, the accumulation of a local algogenic
substance, the increase in the release of peripheral endogenous analgesia materials
and the regulation of c-Fos gene (immediate early gene).