Glycyrrhizae Radix et Rhizoma Processed by Sulfur Fumigation Damaged the Chemical Profile Accompanied by Immunosuppression and Liver Injury.

Glycyrrhizae Radix et Rhizoma (GRER) has been used as a medicinal plant and dietary supplements for its beneficial effect in immunomodulatory effects. Sulfur fumigation (SF) processing was widely used in the storage and maintenance of Chinese medicine because of its convenience and cheapness. However, the disadvantage of SF has been reported, but the systematic study of SF on GRER was deficient. In this paper, the active ingredients, sulfur-fumigated products, immunomodulatory effect, and liver injury of SF-GRER were studied. After SF, the liquiritin decreased from 4.49 ± 0.03 mg/g to 3.94 ± 0.08 mg/g (P < 0.01). Compared with the NSF-GRER group, the SF-GRER group showed a decreased immunoregulation in the thymus index, spleen index, and serum IL-6 and SOD levels (P < 0.05). After 2 weeks of continuous intragastric administration of SF-GRER in healthy mice, the level of serum aspartate aminotransferase (AST) significantly increased (P < 0.05) and the area of liver lesion significantly increased compared with the NSF-GRER (P < 0.05) group. The sulfonated products (m/z, 631.13) corresponding to liquiritin apioside (m/z, 551.17) and isoliquiritin apioside (m/z, 551.17) were screened out in SF-GRER by using UPLC-Orbitrap-MS. The sulfonated products provided in this paper were discovered for the first time and could be powerfully applied for the identification of SF-GRER. SF destroyed the chemical composition of GRER, inhibited immunoregulation, and induced liver injury. The feasibility of this processing method needs to be reconsidered.