Standard reference material (SRM) DNA barcode library approach for authenticating Antidesma bunius (L.) Spreng. (bignay) derived herbal medicinal products

In the Philippines, the herbal medicinal product (HMP) market is flourishing due to the abundance of pharmacologically important species, and the high level of ethnomedicinal knowledge still widely accepted by the public. As such, herbal products from Antidesma bunius (L.) Spreng., locally known as bignay, are popular as medicine for various ailments of the circulatory and digestive systems. Though efficacy is guaranteed, the authenticity of the marketed products is still in question as several other herbal plants can provide the said benefits. Similar morphology between wild species also hinders species identification and contributes confusion especially to the general consumer. The authenticity of the marketed HMPs was established by means of DNA barcoding techniques which offers quick and reliable species identification by means of (1) the Basic Local Alignment Search Tool (BLASTn) and (2) the establishment of the first Standard Reference Material (SRM) Herbal barcode library for Antidesma spp. A total of 56 gene accessions from matK-psbA-trnH-rbcL sequences of 9 wild Antidesma spp. comprised the SRM which was then used to confirm the identity of 11 randomly sampled bignay-derived HMPs. Following the BLASTn and the SRM (maximum likelihood tree reconstruction) criterion, the subjected sequences revealed that only three of the 11 HMPs were authentic A. bunius-derived products. The other eight HMPs contained substitutes that were either fillers or different herbal medicinal plant not indicated in the product labels. These results indicate that product safety should be reinforced with complete HMP authentication using traditional methods supported by molecular data.