Quality Characterization of Japanese Medicinal Paeoniae Radix by Metallomic Analysis

Paeoniae Radix is one of the crude drugs frequently used in traditional Japanese medicine (Kampo medicine). It takes abundant labor and time to cultivate Paeonia lactiflora for medicinal use; high production cost is one of the main reasons why the domestic production of Paeoniae Radix is decreasing in Japan. To promote the production of Paeoniae Radix, we focused on Paeonia cultivars that produce commercially valuable flowers and investigated their possibility for medicinal use. We prepared 28 batches of peony roots derived from P. lactiflora, which were cultivated in Japan; 4 batches were crude drug samples, and 24 batches were cultivar roots. The elements contained in these samples were measured using inductively coupled plasma (ICP)-MS. The obtained data were then analyzed by principal component analysis (PCA) and back propagation artificial neural network (BPANN) analysis. No significant differences were found between the profiles of elements contained in crude drugs and cultivar roots. However, PCA results indicated a high similarity of the multielement fingerprints of crude drugs. Using the PCA results, we also assessed visible cluster trends and found that 5 batches of cultivars also showed fingerprints related to those of crude drugs. We certified this classification by BPANN. From the perspective of metallomics, our findings suggest that these 5 batches of Paeonia cultivars could be alternatives to crude drugs.