[Identification of water buffalo horn and its adulterants using COI barcode]

Bubali cornu (water buffalo horn) has been used as the substitute for Cornu rhinoceri asiatici (rhino horn) in clinical applications, and is the essential ingredient of Angong Niuhuang Wan. In recent years, there are a number of adulterants on the commercial herbal medicine markets. An efficient tool is required for species identification. In this study, 155 Bubali cornu samples have been taken from original animals and collected from commercial herbal medicine markets. 153 COI sequences have been successfully obtained from 155 samples through DNA extraction, PCR amplification, bidirectional sequencing and assembly. 93 COI sequences have been added to the DNA barcoding database of traditional Chinese animal medicine after validation using DNA barcoding GAP and tree-based methods. The species identification of the 62 commercial Bubali cornu medicines has been accomplished on the DNA barcoding system for identifying herbal medicine using the updated animal medicine database (www.tcmbarcode.cn). Except two samples failed to obtain COI sequences, 54.8% of the commercial Bubali cornu medicines were water buffalo horns and 29% were yak horns. Our results showed that yak horn was the major adulterant of Bubali cornu and the DNA barcoding method may accurately discriminate Bubali cornu and their adulterants. Therefore, we recommend that supervision on the herbal medicine markets should be strengthened with this new method to warren the effectiveness of herbal medicines.