Ultra-Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS)-Based Pharmacokinetics and Tissue Distribution Study of Koumine and the Detoxification Mechanism of Glycyrrhiza uralensis Fisch on Gelsemium elegans Benth.

Abstract

Gelsemium elegans Benth. (G. elegans), which is a famous Chinese folk medicine, has been commonly used to treat certain types of skin ulcers and alleviate inflammation, headaches, and cancer pain. However, the extensive clinical use of G. elegans has been greatly hampered by its toxicity. As one of the most widely used herbal medicines, Glycyrrhiza uralensis Fisch, has a unique effect on detoxification of G. elegans. In the present study, a rapid and sensitive method using ultra-liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established and validated for determination of koumine, the most abundant molecule among the alkaloids of G. elegans, in rat plasma, tissue, and liver microsome. The developed method was successfully applied to the pharmacokinetics, tissue distribution, and in vitro metabolism study in rat with or without pre-treated Glycyrrhiza uralensis Fisch extract. Meanwhile, the expression level of CYP3A1 mRNA was analyzed to explain the detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans. As a result, our work demonstrated that Glycyrrhiza uralensis Fisch could significantly affect the pharmacokinetics and tissue distribution of koumine in rats. The detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans may be its cytochrome enzyme up-regulation effect.

Orally Administered Koumine Persists Longer in the Plasma of Aged Rats Than That of Adult Rats as Assessed by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

“…Considering the difficulty associated with blood collection in aged rats, this new method is beneficial as it requires only 50 ml of plasma unlike previously reported methods that require 100 ml (Chen et al, 2013;Wang et al, 2018a;Wang et al, 2018b). Moreover, the LLOQ of the new method was 0.2 ng/ml, which implies more sensitivity than the LLOQ achieved in some previous studies (Chen et al, 2013;Xu et al, 2013) and similar to that reported in others (Wang et al, 2018a;Wang et al, 2018b;Yang et al, 2018). This facilitates the detection of KM in the lowdose group 12 h following administration.…”

“…We had previously performed a pharmacokinetic analysis of KM in rat plasma following an intragastric administration of 15 mg•kg −1 KM powder (purity >99.1%) (Xu et al, 2013), which revealed a T max and t 1/2 of 19.95 ± 0.53 min (equivalent time in hours: 0.33 ± 0.01 h) and 234.11 ± 17.34 min (equivalent time in hours: 3.90 ± 0.29 h), respectively. Wang et al investigated the pharmacokinetics of KM in rat plasma following oral administration of a G. elegans extract (single dose: 10 mg•kg −1 ) equivalent to 1.22 mg•kg −1 KM (Wang et al, 2018a;Wang et al, 2018b). They observed a T max and t 1/2 of 0.28 ± 0.07 h and 1.60 ± 0.21 h, respectively.…”

“…For the 1.4 and 7.0 mg•kg −1 orally administered doses, we found that the T max of KM occurred approximately 0.3 h later in aged rats. This difference likely resulted from age-associated changes in the gastrointestinal tract and hepatorenal function, including decreases in gastric emptying time, gastrointestinal peristalsis, bowel surface area, and splanchnic blood flow (Wang et al, 2018a;Zeng et al, 2019). When the KM dose was increased from 0.28 to 1.4 mg•kg −1 and from 1.4 to 7.0 mg•kg −1 , the AUC 0-t and AUC 0-∞ did not increase proportionally with the dose (Table 4), which was indicative of the nonlinearity of the pharmacokinetics for the 7.0 mg•kg −1 dose.…”

“…Pharmacokinetic profiling is vital for understanding the in vivo behavior and mechanism of action of a drug. On account of its diverse biological activities, many metabolic and excretion studies in rats (Chen et al, 2013;Wang et al, 2018a;Wang et al, 2018b), pigs (Yang et al, 2018;Liu et al, 2019), and goats (Cao et al, 2020;Zuo et al, 2020) have investigated the role of KM. However, the dose proportionality of KM following oral administration, particularly in aged individuals, remains unknown.…”

Toxicokinetics of 11 Gelsemium Alkaloids in Rats by UPLC-MS/MS

“…There have been methods reported for the determination of Gelsemium alkaloids, including high performance liquid chromatography-tandem (HPLC) [15,16], ultraperformance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) [17,18], liquid chromatography/tandem mass spectrometry (LC/MS/MS) [19][20][21][22][23], and ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) [24][25][26][27][28] in vivo. However, a method has not been found for the simultaneous determination of 11 Gelsemium alkaloids in rat plasma, and the toxicokinetics of 11 Gelsemium alkaloids (humantenirine, humantenine, akuammidine, gelsevirine, rankinidine, n-methoxyanhydrovobasinediol, gelsenicine, gelsemine, koumine, koumidine, and sempervirine) after intravenous administration has not been reported.…”