Sophorae tonkinensis Radix et Rhizoma (S. tonkinensis) has been recorded as a ‘poisonous’ Chinese herbal medicine in Chinese Pharmacopoeia 2020. The clinical reaction reports of S. tonkinensis indicated its neurotoxicity; however, there still exists dispute about its toxic substances. At present, no report is available on the blood and brain prototype research of S. tonkinensis. Most studies focused on alkaloids and less on other compounds. Moreover, the constituents absorbed into the blood and brain have been rarely investigated so far. This study established a rapid and efficient qualitative analysis method using UPLC-Q-TOF-MSE to characterize the ingredients of S. tonkinensis and those entering into the rat's body after oral administration. A total of 91 compounds were identified in S. tonkinensis, of which 28 were confirmed by the standards. In addition, 30 and 19 prototypes were also first identified in the rat's blood and brain, respectively. It was found that most flavonoids, except alkaloids, were detected in the rat's body and distributed in the cerebrospinal fluid, suggesting that flavonoids may be one of the important toxic or effective substances of S. tonkinensis. This finding provides new clues and data for clarifying the toxicity or efficacy of this medicinal plant.
