Xi Jiao

All five rhinoceros species are listed on CITES Appendix I and international commercial trade in rhinoceros horn has been banned under the Convention since 1977. On 29 May 1993 China's State Council prohibited with immediate effect the manufacture of medicines containing rhinoceros horn and required all domestic trade in such medicines to cease within six months, and rhinoceros horn was removed from the official Chinese Pharmacopoeia. A State Council circular of October 2018 that would have created narrow medical exceptions for farmed material was postponed in November 2018 after international objection, leaving the prohibition in force. Demand from consumers of traditional medicine is a documented driver of the poaching that has pushed rhinoceros populations to the edge; Rhinoceros unicornis, the greater one-horned rhinoceros of northern India and southern Nepal, is assessed as Vulnerable on the IUCN Red List with a total population of roughly four thousand animals recovered from fewer than a hundred, and poaching for horn remains the principal threat to that recovery. Forensic laboratories maintain a standardised species identification test and a microsatellite panel specifically to prosecute the trade in this species. This entry exists to record a prohibition and a conservation position, not to describe a usable drug.

Recorded here as a substitution relationship because that is how a practitioner meets it. In the turpentine-fever rat model, aqueous extracts of rhinoceros horn and of water buffalo horn both produced significant antipyretic action at 2.5 g/mL given intraperitoneally, and Qingying Decoction prepared with water buffalo horn gave antipyretic action comparable to the version prepared with rhinoceros horn. Comparative proteomic and bio-effect work on rhinoceros, water buffalo and yak horn reaches the same conclusion, that available sustainable horns can replace the endangered one. The dosage substitution used in Chinese practice is a considerably larger weight of buffalo horn than the rhinoceros horn a classical text specifies, and Chinese Pharmacopoeia dosing for Shui Niu Jiao should be followed rather than the classical Xi Jiao figure.

Because there is no lawful supply chain, everything offered as rhinoceros horn comes from the illegal wildlife trade. Species identification of seized horn is difficult enough that an internationally standardised genetic test had to be developed for it, and forensic microsatellite panels are used to trace Rhinoceros unicornis material seized in India, which tells you directly that visual identification of such material is unreliable. Beyond the legal exposure, illicitly produced animal-derived traditional medicines carry documented risks of zoonotic transmission and of undeclared contamination and adulteration.

Qing Ying Tang was composed with rhinoceros horn and eight herbs, and Xi Jiao Di Huang Tang takes its name from the ingredient. Both are now compounded with water buffalo horn, and Xi Jiao Di Huang Tang is often written Shui Niu Jiao Di Huang Tang for that reason. Direct comparison in the rat fever model found the buffalo horn version of Qingying Decoction comparably antipyretic to the rhinoceros horn version, so the substitution costs nothing measurable. Some older textbooks and translations still print the original ingredient without a note; the ingredient list is a historical artefact of the text, not a current specification.