Pharmacokinetics and tissue distribution of crotonoside.

1. Crotonoside is a bioactive ingredient from Croton Herba with a strong antitumour activity. This study aimed to develop a highly sensitive and selective high-performance liquid chromatography (HPLC) method to quantify crotonoside in biological samples for pharmacokinetics and distribution studies. 2. Protein precipitation by perchloric acid was used to separate crotonoside from the biological samples, and the recovery rates for crotonoside and the internal standard (luteoloside) were >80%. All calibration curves examining the crotonoside levels in plasma and tissues were linear (all correlation coefficients > 0.99). 3. The response to crotonoside appeared to be dose disproportional to the maximum plasma concentration and the area under the time-concentration curve in plasma over the range of 12.5-50.0 mg/kg, and crotonoside was highly distributed in tissues after intravenous administration. The highest crotonoside level was detected in the liver (28.79 ± 14.96 µg/g), whereas crotonoside was undetected in the brain.

Crotonoside exhibits selective post-inhibition effect in AML cells via inhibition of FLT3 and HDAC3/6.

Targeted therapies for the treatment of acute myeloid leukemia (AML), specifically the FLT3 inhibitors, have shown promising results. Nevertheless, it is very unlikely that inhibitors which target a single pathway will provide long-term disease control. Here, we report the characterization of crotonoside, a natural product extracted from Chinese medicinal herb, Croton, for the treatment of AML via inhibition of FLT3 and HDAC3/6. In vitro, crotonoside exhibited selective inhibition in AML cells. In vivo, crotonoside treatment at 70 and 35 mg/kg/d produced significant AML tumor inhibition rates of 93.5% and 73.6%, respectively. Studies on the anti-AML mechanism of crotonoside demonstrated a significant inhibition of FLT3 signaling, cell cycle arrest in G0/G1 phase, and apoptosis. In contrast to classic FLT3 inhibitor; sunitinib, crotonoside was able to selectively suppress the expression of HDAC3 and HDAC6 without altering the expression of other HDAC isoforms. Inhibitors of HDAC3 and HDAC6; RGFP966 and HPOB, respectively, also exhibited selective inhibition in AML cells. Furthermore, we established novel signaling pathways including HDAC3/NF-κB-p65 and HDAC6/c-Myc besides FLT3/c-Myc which are aberrantly regulated in the progression of AML. In addition, crotonoside alone or the combination of sunitinib/RFP966/HPOB exhibited a significant post-inhibition effect in AML cells by the inhibition of FLT3 and HDAC3/6. Inhibitors targeting the FLT3 and HDAC3/6 might provide a more effective treatment strategy for AML. Taken together, the present study suggests that crotonoside could be a promising candidate for the treatment of AML, and deserves further investigations.

A pharmacokinetic study of patchouli alcohol after a single oral administration of patchouli alcohol or patchouli oil in rats.

Pogostemonis herba is used in traditional Chinese medicine to remove dampness, relieve sunstroke, stop vomiting and increase appetite. Patchouli alcohol, an ingredient in pogostemonis herba, has the potential to treat inflammation as well as bacterial and fungal infections. The essential oil of pogostemonis herba (patchouli oil) is commonly given orally in clinical settings; however, no pharmacokinetic studies have examined its oral administration. The goal of this study was to investigate the pharmacokinetic behavior of patchouli alcohol following single-dose oral administration in rats; the influence of other patchouli oil components on the pharmacokinetic profile of patchouli alcohol was also examined. In this study, a simple and selective GC/MS method was developed and validated to measure the level of patchouli alcohol in rat plasma. The study revealed that the pharmacokinetics profile was linear in both the patchouli alcohol and patchouli oil groups. The C max and AUC0-t of patchouli alcohol were greater in all three doses of patchouli alcohol compared to corresponding patchouli oil doses. Additionally, the T max values were significantly greater in the patchouli oil group. These results suggest that the other ingredients in patchouli oil influence the pharmacokinetic behavior of patchouli alcohol during its absorption. The results provide a meaningful basis for evaluating the clinical application of patchouli oil and patchouli alcohol.