Abstract This study investigated the influence of different processing methods on the oral toxicity of Sophora alopecuroides L., Fabaceae, seeds in mice and on the contents of five known toxic-effective quinolizidine alkaloids from the ethanol extracts quantified by ultra-performance liquid chromatography coupled to tandem quadrupole mass spectrometry. It provides an evidence to elucidate the possible reasons why vinegar-processing and parching methods significantly decrease the acute oral toxicity induced by S. alopecuroides and why wine-processing method increases it instead (demonstrated by measurement of LD50 and histopathological analysis). The analytical performance for the determination of the five analytes was evaluated by linearity, stability, repeatability, precision and accuracy, and recovery test. The lowest limit of quantification was determined to be 5 ng/ml for each substance and the precision and accuracy at lowest limit of quantification were below 20%. Cytisine, the most toxic alkaloid among the five alkaloids, declined 11.26, 3.98, and 2.73 folds after being vinegar-processed and fried in a ceramic or iron pan, respectively and had a very close correlation with the toxicity of S. alopecuroides seeds (r = 0.8589). Other matrine-type alkaloids with lower toxicity including matrine, sophcarpine, and sophoridine decreased after being wine-processed and fried in a ceramic pan, but increased 4.44, 7.20, and 7.23 folds when being processed by vinegar. Oxymatrine declined in all groups. It, therefore, reveals that vinegar-processing method reduces the oral toxicity of S. alopecuroides mainly due to a sharp decrease of cytisine, thus improves its clinical safety.

Abstract Kudouzi (Sophora alopecuroides L., Fabaceae) is an effective folk medicine, but it always causes a hepatic and renal toxicity in clinical therapy. The toxic mechanism remains unclear. This paper detected the urinary and plasma metabolites alteration by 1H NMR-based metabonomics study in Kudouzi-induced rats to evaluate the toxic mechanism for clinical security. The male Sprague-Dawley rats were orally dosed with 0.5 and 1 g Kudouzi/kg weight once per day for consecutive 14 days. Urine samples were collected at day −1 (before treatment), and days 7, 14, and 21 for NMR analysis, respectively. Plasma samples were harvested at day 14 for NMR and biochemical analysis. The metabonomic profiling of Kudouzi-treated rats differed from that of the vehicle. This was confirmed by the biochemistry analysis. The accumulated subacute toxicity of Kudouzi was visible with dosing time, and persisted at day 21 even after the disposal was ended. The observable biochemical pathways alterations included inhibited TCA cycle, activated anaerobic glycolysis, perturbed amino acids metabolism, and disordered gut microbiota. The results evidenced the toxicity mechanism of Kudouzi from a systematic and holistic view.

ABSTRACT The present study describes the impact of chrysosplenetin, in the absence and presence of artemisinin, on in vitro breast cancer resistance protein-mediated transport activity in Caco-2 cell monolayers using aristolochic acid I as a specific probe substrate. We observed that novobiocin, a known breast cancer resistance protein active inhibitor, increased Papp (AP-BL) of aristolochic acid I 3.13 fold (p < 0.05) but had no effect on Papp (BL-AP). Efflux ratio (PBA/PAB) declined 4.44 fold (p < 0.05). Novobiocin, consequently, showed a direct facilitation on the uptake of AAI instead of its excretion. Oppositely, both artemisinin and chrysosplenetin alone at dose of 10 µM significantly decreased Papp (BL-AP) instead of Papp (AP-BL). Chrysosplenetin alone attenuated the efflux ratio, which was suggestive of being as a potential breast cancer resistance protein suppressant. Oddly, Papp (BL-AP) as well as efflux ratio were respectively enhanced 2.52 and 2.58 fold (p < 0.05), when co-used with artemisinin and chrysosplenetin in ratio of 1:2. The potential reason remains unclear; it might be relative to binding sites competition between artemisinin and chrysosplenetin or the homodimer/oligomer formation of breast cancer resistance protein bridged by disulfide bonds, leading to an altered in vitro breast cancer resistance protein-mediated efflux transport function.

ABSTRACT Our previous work revealed that chrysosplenetin in combination with artemisinin inhibited in vivo P-glycoprotein (P-gp, one of classic multi-drug resistance proteins) mediated digoxin transportation activity by reversing the upregulated P-gp/Mdr1 mRNA expression levels by artemisinin. Therefore, chrysosplenetin might be a potential artemisinin-resistance reversal agent as a P-gp inhibitor. But it still remains unknown if chrysosplenetin has an impact on another pivotal multi-drug resistance protein, breast cancer resistance protein (Bcrp), which is co-expressed with P-gp in apical membrane of intestinal epithelial cell and overlaps some of the substrates and inhibitors. This study, therefore, further addressed the impact of chrysosplenetin, per se or in combination with artemisin, on Bcrp/ABCG2 mRNA expression levels in mice small intestine determined by western blot and real time-quantitative polymerase chain reaction (RT-qPCR) assay. The drugs were intragastrically administrated once per day for 7 days. Novobiocin, a known Bcrp inhibitor, was observed to have no impact on Bcrp/ABCG2 levels with or without artemisinin versus vehicle. Interestingly, artemisinin alone attenuated Bcrp level while chrysosplenetin alone increased it (p < 0.05). Relative mRNA level was significantly decreased when co-used with artemisinin and chrysosplenetin in ratio of 1:2 (p < 0.05). The discrepant results for chrysosplenetin on Bcrp/ABCG2 mRNA expressions might be closely related to the transcriptional or posttranscriptional regulation.