Differences in Intestinal Metabolism of Ginseng Between Normal and Immunosuppressed Rats

Ginseng is usually consumed as a dietary supplement for health care in the normal state or prescribed as a herbal medicine in pathologic conditions. Although metabolic studies of ginseng are commonly performed on healthy organisms, the metabolic characteristics in pathologic organisms remain unexplored. This study aimed to uncover the difference in intestinal metabolism of ginseng between normal and cyclophosphamide-induced immunosuppressed rats and further discuss the potential mechanisms involved.

Twelve Sprague-Dawley rats (6-8 weeks old) were randomly divided into two groups: the normal group (NG) and immunosuppressed group (ISG). Rats in the NG and ISG groups were intraperitoneally administered normal saline and cyclophosphamide injections (40 mg/kg) on the 1st, 2nd, 3rd and 10th days; on the 12th day, all rats were intragastrically administered ginseng water extract (900 mg/kg). The difference in intestinal metabolism of ginseng was compared using an ultra-high-performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry-based metabolomics approach, and the diversities of gut microbiota were analyzed by 16S rRNA gene sequencing between the two groups.

The intestinal metabolomic characteristics of ginseng were significantly different between the normal and immunosuppressed rats, with the ginsenoside F₂ (F₂), 20S-ginsenoside Rg₃ (20(S)-Rg₃), pseudo-ginsenoside Rt₅ (Pseudo-Rt₅), ginsenoside Rd (Rd), ginsenoside Rh₁ (Rh₁), 20S-ginsenoside Rg₁ (20(S)-Rg₁), ginsenoside compound K (CK), ginsenoside Rg₂ (Rg₂) and 20S-panaxatriol (S-PPT) more abundant in immunosuppressed ones (P < 0.05). Additionally, the composition of gut microbiota was remarkably altered in the two groups, with some specific bacterial communities such as Bacteroides spp., Eubacterium spp. and Lachnospiraceae_UCG-010 spp. increased and Bifidobacterium spp. decreased in immunosuppressed rats compared with normal ones.

The intestinal metabolism of ginseng in immunosuppressed rats was significantly different from that in normal ones, which might be partly attributed to the changes in the intensity of specific gut bacteria. The outcomes of this study could provide scientific data for rationalization of ginseng use as both a dietary supplement and herbal medicine.