Atractylodis Rhizoma is the dried rhizome of Atractylodes lancea (Thunb.) DC. or Atractylodes chinensis (DC.) Koidz and is often processed by stir-frying with wheat bran to reduce its dryness and increase its spleen tonifying activity. However, the mechanism by which the processing has this effect remains unknown. To explain the mechanism based on the pharmacokinetics of the active compounds, a rapid, sensitive ultra-performance liquid chromatography-tandem mass spectrometry method was developed to analyze atractylenolides I, II, and III, and atractyloside A simultaneously in rat plasma after oral administration of raw and processed Atractylodis Rhizoma. Acetaminophen was used as the internal standard and the plasma samples were pretreated with methanol. Positive ionization mode coupled with multiple reaction monitoring mode was used to analyze the four compounds. The method validation revealed that all the calibration curves displayed good linear regression over the concentration ranges of 3.2–350, 4–500, 4–500, and 3.44–430 ng/mL for atractylenolides I, II, and III, and atractyloside A, respectively. The relative standard deviations of the intra- and inter-day precisions of the four compounds were less than 6% with accuracies (relative error) below 2.38%, and the extraction recoveries were more than 71.90 ± 4.97%. The main pharmacokinetic parameters of the four compounds were estimated with Drug and Statistics 3.0 and the integral pharmacokinetics were determined based on an area under the curve weighting method. The results showed that the integral maximum plasma concentration and area under the curve increased after oral administration of processed Atractylodis Rhizoma.

Atractylodis Rhizoma (AR), a kind of well-known traditional Chinese medicine (TCM), has a long history of being used to treat spleen-deficiency syndrome (SDS). Stir frying with bran is a common method of processing AR, as recorded in the Chinese Pharmacopoeia, and is thought to enhance the therapeutic effect in TCM. Our previous studies have confirmed that bran-fried AR is superior to raw AR in terms of the improvement of gastrointestinal tract function. However, the biological mechanism of action is not yet clear. Here, we report the difference between raw and bran-fried AR in terms of the modulatory effect of intestinal microbiota. We found that the composition of intestinal microbiota of SDS rats changed significantly compared with healthy rats and tended to recover to normal levels after treatment with raw and bran-fried AR. Nine bacteria closely related to SDS were identified at the genus level. Among them, the modulatory effect between the raw and bran-fried AR was different. The improved modulation on Bacteroides, Escherichia-Shigella, Phascolarctobacterium, Incertae-Sedis (Defluviitaleaceae Family) and Incertae-Sedis (Erysipelotrichaceae Family) could be the mechanism by which bran-fried AR enhanced the therapeutic effect. Correlation analysis revealed that the modulation on intestinal microbiota was closely related to the secretion and expression of cytokines and gastrointestinal hormones. These findings can help us to understand the role and significance of bran-fried AR against SDS.

Gentiana radix is used in traditional Chinese medicine and has functions of clearing heat and drying dampness, as well as purging liver and gallbladder fire. A highly sensitive and effective strategy for rapid screening and identification of target constituents has been developed by using ultra high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap) in crude and wine-processed Gentiana radix. Based on the accurate mass measurement (<5 ppm), retention times, and MS fragmentation ions, 52 constituents were unambiguously or tentatively characterized from Gentiana radix, including 21 iridoids, 11 flavonoids, 19 xanthones, and a triterpenoid. This study demonstrated that the established method could be a rapid, effective analytical tool for screening and characterization of compounds in the complex systems of Gentiana radix. By comparing the structure and peak areas of chemical constituents in crude and wine-processed Gentiana radix, we found that some compounds in crude and wine-processed Gentiana radix were significantly different.