Regulation of Zhi-Zi-Chi decoctions on intestinal flora

Zhi-Zi-Chi decoction (ZZCD), composed of Gardeniae Fructus and Semen sojae praeparatum, is a classical prescription that eliminates restlessness and improves insomnia, and is documented in Treatise on Febrile Diseases written by Zhang Zhongjing. The modern clinical application of ZZCD shows that it is effective in regulating and ameliorating depression. Nevertheless, the antidepressant mechanism of ZZCD remains largely unknown thus far. Interested in the antidepressant efficacy of ZZCD, we have been committed to the study of ZZCD and the single herbs in the past years. More specifically, we have conducted qualitative and quantitative studies on the chemical constituents of Gardeniae Fructus[6] and Semen sojae praeparatum and demonstrated the neuroprotective effect of ZZCD via cell metabolomics. Meanwhile, our previous studies showed that isoflavones in Semen sojae praeparatum could significantly influence the composition of gut microbiota in rats, thereby affecting the metabolic characteristics of main iridoids in Gardeniae Fructus. Our preliminary work laid the solid foundation for in-depth study on the antidepressant mechanism of ZZCD.