Determination of the Genomic DNA Degradation Rate of the Chinese Herb Gentianae crassicaulis Radix During Processing and Storage

Background Accurate identification of Chinese herbal medicines is the basis for their research and utilization. Molecular identification can effectively differentiate original plants from counterfeit plants. The quality of genomic DNA is an important factor affecting molecular identification. However, the processing can lead to DNA degradation of the herbal medicines, which can make it difficult for their molecular identification. Objectives To establish a genomic DNA degradation model of Gentiana crassicaulis Radix to evaluate the effects of processing methods and storage times on genomic DNA integrity. Materials and Methods A genomic DNA degradation model of G. crassicaulis-the original plant source of the Chinese herbal medicine G. crassicaulis Radix-was established using a steam heating method. Genomic DNA integrity of G. crassicaulis Radix was evaluated using capillary electrochromatography (CEC) fingerprinting and polymerase chain reaction (PCR) of DNA barcoding markers following different processing and drying methods, including slicing (sliced roots), no slicing (whole roots), stoving, air drying, and sweating. Results CEC fingerprinting and DNA barcoding PCR effectively evaluated genomic DNA integrity. Compared to whole roots, sliced roots better helped maintain genomic DNA integrity. As the storage time increased, the integrity of the genomic DNA reduced; the integrity of the genomic DNA of sliced roots was greater than that of whole roots. Furthermore, the interactions between slicing and drying methods possibly reduced the genomic DNA integrity. Conclusion A genomic DNA degradation model and an evaluation system for herbal medicines were established. Our findings can help optimize the method for processing G. crassicaulis Radix and establish the traceability of genuine herbal medicines. Key Message The quality of genomic DNA is an important factor affecting molecular identification, which is essential to determine original plants. The results of our study can help develop a method for processing G. crassicaulis Radix and enable the traceability of genuine herbal medicines.