protopanaxadiol and Colonic-Neoplasms

In this study, we evaluated the effects of protopanaxadiol (PPD), a gut microbiome induced ginseng metabolite, in increasing the anticancer effects of a chemotherapeutic agent fluorouracil (5-FU) on colorectal cancer. An in vitro HCT-116 colorectal cancer cell proliferation test was conducted to observe the effects of PPD, 5-FU and their co-administration and the related mechanisms of action. Then, an in vivo xenografted athymic mouse model was used to confirm the in vitro data. Our results showed that the human gut microbiome converted ginsenoside compound K to PPD as a metabolite. PPD and 5-FU significantly inhibited HCT-116 cell proliferation in a concentration-dependent manner (both p<0.01), and the effects of 5-FU were very significantly enhanced by combined treatment with PPD (p<0.01). Cell cycle evaluation demonstrated that 5-FU markedly induced the cancer cell S phase arrest, while PPD increased arrest in G1 phase. Compared to the control, 5-FU and PPD increased apoptosis, and their co-administration significantly increased the number of apoptotic cells (p<0.01). Using bioluminescence imaging, in vivo data revealed that 5-FU significantly reduced the tumor growth up to Day 20 (p<0.05). PPD and 5-FU co-administration very significantly reduced the tumor size in a dose-related manner (p<0.01 compared to the 5-FU alone). The quantification of the tumor size and weight changes for 43 days supported the in vivo imaging data. Our results demonstrated that the co-administration of PPD and 5-FU significantly inhibited the tumor growth, indicating that PPD significantly enhanced the anticancer action of 5-FU, a commonly used chemotherapeutic agent. PPD may have a clinical value in 5-FU's cancer therapeutics.

Topics: Animals; Antimetabolites, Antineoplastic; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Cell Cycle; Cell Proliferation; Colonic Neoplasms; Disease Models, Animal; Fluorouracil; HCT116 Cells; Humans; Mice; Mice, Nude; Panax; Sapogenins; Treatment Outcome; Xenograft Model Antitumor Assays

To study the alkaline-degradation products of ginsenosides from leaves and stems of Panax quinquefolium L.. Isolation and purification were carried out on silica gel and HPLC; the structures of chemical constituents were elucidated by spectral analysis.. From the alkaline-degradation products, nine compounds were identified as: 20 (S) -protopanaxadiol (I), 20 (S) -dammar-25 (26)-ene-3beta, 12beta, 20-triol (II), 24 (R) -ocotillol (III), 20 (S) -protopanaxatriol (IV), 20 (S) -dammar-25 (26)-ene-3beta, 6alpha, 12beta, 20-tetrol (V), dammar-20 (21), 24-diene-3beta, 12beta-diol (VI), dammar-20(21), 24-diene-3beta, 6alpha, 12beta-triol (VII), 20 (S), 24 (S) -dammar-25 (26) -ene-3beta, 6alpha, 12beta, 20, 24-pentanol (VIII), 20 (S) -dammar-23-ene-25-hydroperoxyl-3beta, 6alpha, 12beta, 20-tetrol (IX).. The configuration of C20 position of ginsenosides was not changed by alkaline-degradation. The complete assignments of 1H and 13C NMR chemical shifts of four new compounds V, VII, VIII, IX, were acquired by means of 2D NMR spectra. Compound I showed antitumor effect on human colon carcinoma cells in vitro.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Ginsenosides; Humans; Molecular Conformation; Molecular Structure; Panax; Plant Leaves; Plant Stems; Plants, Medicinal; Sapogenins; Triterpenes