Daikenchuto (TU-100) alters murine hepatic and intestinal drug metabolizing enzymes in an in vivo dietary model: effects of gender and withdrawal

Involvement of phase II enzymes and efflux transporters in the metabolism and absorption of naringin, hesperidin and their aglycones in rats

This study examined the effects of phase II metabolism and efflux transportation on the bioavailability of naringin, hesperidin, and their aglycones (naringenin and hesperetin) in rats. Results indicated naringin and hesperidin have a lower oral bioavailability than their aglycones. Of all the phase II enzymes tested, UDP-glucuronosyltransferase (UGT) 1A1, UGT1A2, UGT1A3, UGT1A7 and SULT sulfotransferase (SULT) 1B1 were of minor importance regarding the phase II metabolism of naringenin and hesperetin in the small intestine. Naringin, hesperidin, and their aglycones were all extensively metabolised in the liver. Naringin and hesperidin were more extensively transported by efflux transporters compared to their aglycones. Significant correlations between phase II enzymes and efflux transporters were detected. In conclusion, more extensive metabolism of naringin and hesperidin than their aglycones in the small intestine, and the interplay of phase II enzymes and efflux transporters in the small intestine explain the lower relative oral bioavailability of naringin and hesperidin than their aglycones.

Inhibitory Effect of Japanese Traditional Kampo Formula Frequently Prescribed in Gynecological Clinics on CYP3A4

Recently, the use of herbal medicines has become popular, and information on drug interactions between herbal medicines and chemical drugs is needed in clinics. In Japan, the number of patients taking Japanese traditional Kampo medicines has been increasing, and the proper drug information about herb-drug interaction is highly demanded. The most established herb-drug interaction is the case of grapefruit juice (GFJ) via the inhibition on CYP3A4 expressed in the small intestine. In the present study, we compared the inhibitory titer on CYP3A4 between the target Kampo products and GFJ used as positive control. We evaluated the inhibitory effects of GFJ and three extracts of Kampo formulas frequently used in gynecological clinics on CYP3A4 in vitro and calculated the related titer of one-time dosage of Kampo formulas to GFJ in order to predict its effect on clinics. Although the extracts of these three Kampo formulas and the most of crude drug components in the formulas exhibited the inhibitory effects on CYP3A4 in some levels, the possibilities of tokishakuyakusan and keishibukuryogan to cause drug interaction can be quite low; however, it is possible that the excessive dosage of kamishoyosan may cause drug interaction with the substrate of CYP3A4 in clinics.

Minimizing confounders and increasing data quality in murine models for studies of the gut microbiome

Murine models are widely used to explore host-microbe interactions because of the challenges and limitations inherent to human studies. However, microbiome studies in murine models are not without their nuances. Inter-individual variations in gut microbiota are frequent even in animals housed within the same room. We therefore sought to find an efficient and effective standard operating procedure (SOP) to minimize these effects to improve consistency and reproducibility in murine microbiota studies. Mice were housed in a single room under specific-pathogen free conditions. Soiled cage bedding was routinely mixed weekly and distributed among all cages from weaning (three weeks old) until the onset of the study. Females and males were separated by sex and group-housed (up to five mice/cage) at weaning. 16S rRNA gene analyses of fecal samples showed that this protocol significantly reduced pre-study variability of gut microbiota amongst animals compared to other conventional measures used to normalize microbiota when large experimental cohorts have been required. A significant and consistent effect size was observed in gut microbiota when mice were switched from regular chow to purified diet in both sexes. However, sex and aging appeared to be independent drivers of gut microbial assemblage and should be taken into account in studies of this nature. In summary, we report a practical and effective pre-study SOP for normalizing the gut microbiome of murine cohorts that minimizes inter-individual variability and resolves co-housing problems inherent to male mice. This SOP may increase quality, rigor, and reproducibility of data acquisition and analysis.

Daikenchuto (TU-100) alters murine hepatic and intestinal drug metabolizing enzymes in an in vivo dietary model: effects of gender and withdrawal

Herbal medicines and natural products used for maintenance of health or treatment of diseases have many biological effects, including altering the pharmacokinetics and metabolism of other medications. Daikenchuto (TU‐100), an aqueous extract of ginger, ginseng, and Japanese green pepper fruit, is a commonly prescribed Kampo (Japanese herbal medicine) for postoperative ileus or bloating. The effects of TU‐100 on drug metabolism have not been investigated. In this study, we analyzed the effect of TU‐100 on expression of key drug‐metabolizing enzymes (DMEs) and drug transporters (DTs) in murine liver and gastrointestinal tract using a dietary model. Liver, jejunum, and proximal colon were analyzed for phase I and II DMEs and DT mRNA expression by reverse transcription (RT) first by nonquantitative and followed by quantitative polymerase chain reaction (PCR) and protein expression. Liver, jejunum, and proximal colon expressed some identical but also unique DMEs and DTs. TU‐100 increased the greatest changes in cytochrome (Cyp) 2b10 and Cyp3a11 and Mdr1a. Basal and TU‐100 stimulated levels of DME and DT expression were gender‐dependent, dose‐dependent and reversible after cessation of TU‐100 supplementation, except for some changes in the intestine. Quantitative Western blot analysis of protein extracts confirmed the quantitative PCR results.

Time-, Sex-, and Dose-Dependent Alterations of the Gut Microbiota by Consumption of Dietary Daikenchuto (TU-100)

Medications or dietary components can affect both the host and the host's gut microbiota. Changes in the microbiota may influence medication efficacy and interactions. Daikenchuto (TU-100), a herbal medication, comprised of ginger, ginseng, and Japanese pepper, is widely used in Japanese traditional Kampo medicine for intestinal motility and postoperative paralytic ileus. We previously showed in mice that consumption of TU-100 for 4 weeks changed the gut microbiota and increased bioavailability of bacterial ginsenoside metabolites. Since TU-100 is prescribed in humans for months to years, we examined the time- and sex-dependent effects of TU-100 on mouse gut microbiota. Oral administration of 1.5% TU-100 for 24 weeks caused more pronounced changes in gut microbiota in female than in male mice. Changes in both sexes largely reverted to baseline upon TU-100 withdrawal. Effects were time and dose dependent. The microbial profiles reverted to baseline within 4 weeks after withdrawal of 0.75% TU-100 but were sustained after withdrawal of 3% TU-100. In summary, dietary TU-100 changed mouse microbiota in a time-, sex-, and dose-dependent manner. These findings may be taken into consideration when determining optimizing dose for conditions of human health and disease with the consideration of differences in composition and response of the human intestinal microbiota.