Evaluation of mycotoxins, mycobiota and toxigenic fungi in the traditional medicine Radix Dipsaci

Medicinal herbs have been increasingly used for therapeutic purposes against a diverse range of human diseases worldwide. However, inevitable contaminants, including mycotoxins, in medicinal herbs can cause serious problems for humans despite their health benefits. The increasing consumption of medicinal plants has made their use a public health problem due to the lack of effective surveillance of the use, efficacy, toxicity, and quality of these natural products. Radix Dipsaci is commonly utilized in traditional Chinese medicine and is susceptible to contamination with mycotoxins. Here, we evaluated the mycotoxins, mycobiota and toxigenic fungi in the traditional medicine Radix Dipsaci. Among the sixty-three batches of Radix Dipsaci samples, we found that a total of twenty-eight batches (44.4%) were contaminated with mycotoxins including AFB1, AFG1, OTA, ZEN, AFG2 and T-2. More than 60% of the contaminated samples were combined with multiple mycotoxins. Fungal diversity and community were altered in the Radix Dipsaci contaminated with various mycotoxins. The abundance of Aspergillus and Fusarium increased in the Radix Dipsaci contaminated with aflatoxins and ZEN. A total of ninety-five strains of potentially toxigenic fungi were isolated from the Radix Dipsaci samples contaminated with mycotoxins, predominantly comprising Aspergillus (73.7%), Fusarium (20.0%), and Penicillium (6.3%). Through morphological identification, molecular identification, mycotoxin synthase gene identification and toxin production verification, we confirmed that AFB1 and AFG1 primarily derive from A. flavus, OTA primarily derives from A. westerdijkiae, ZEN primarily derives from F. oxysporum, and T-2 primarily derives from F. graminearum in Radix Dipsaci. These data may help to provide useful information for effective prevent, control, and degrade contaminants strategies to ensure the safety of traditional medicine Radix Dipsaci.