Cell experiment:

An MTS assay is used to analyze the effects of the compounds on cell viability. HepG2 cells are cultured overnight in a 96-well plate (1×104 cells/well). Cell viability is assessed after adding the compounds (e.g., Ginsenoside Rd; 0.1, 1, and 10 μM) for 24 h. The number of viable cells is determined by the A490nm of the dissolved formazan product, after addition of MTS for 30 min[1].

Animal experiment:

Mice[3]Heterozygous male ApcMin/+ (C57BL/6J-ApcMin/+) mice are used. Total 32 male ApcMin/+ mice (aged 6 weeks) are divided into three groups; 10 mice in the control group and 22 mice equally divided for Rb3 and Rd treatments. The mice are daily gavage with a single dose of Ginsenoside Rb3 or Ginsenoside Rd at 20 mg/kg, or solvent control. The treatments are carried out for 8 consecutive weeks.

Ginsenoside Rd inhibits TNFα-induced NF-κB transcriptional activity with an IC50 of 12.05±0.82 μM in HepG2 cells. Ginsenoside Rd inhibits expression of COX-2 and iNOS mRNA. Ginsenoside Rd also inhibits Ca2+ influx. Ginsenoside Rd inhibits CYP2D6, CYP1A2, CYP3A4, and CYP2C9, with IC50s of 58.0±4.5 μM, 78.4±5.3 μM, 81.7±2.6 μM, and 85.1±9.1 μM, respectively.

Ginsenoside Rd is one of the most abundant ingredients of Panax ginseng. Ginsenoside Rd significantly inhibits TNF-α-induced NF-κB transcriptional activity with an IC50 of 12.05±0.82 in HepG2 cells. Ginsenoside Rd also inhibits expression of COX-2 and iNOS mRNA and iNOS promoter activity in a dose-dependent manner. To determine nontoxic concentrations, HepG2 cells are treated with various concentrations (0.1, 1, and 10 μM) of compounds (e.g., Ginsenoside Rd) and cell viability is measured using an MTS assay. No compounds are significantly cytotoxic at up to 10 μM, indicating that NF-κB inhibition is not due to cell toxicity[1]. Ginsenoside Rd is one of the most abundant ingredients of Panax ginseng, protects the heart via multiple mechanisms including the inhibition of Ca2+ influx. Ginsenoside Rd reduces ICa,L peak amplitude in a concentration-dependent manner (IC50=32.4±7.1 μM)[2]. Ginsenoside Rd exhibits an inhibition against the activity of CYP2D6 in human liver microsomes with an IC50 of 58.0±4.5 μM, a weak inhibition against the activity of CYP1A2, CYP3A4, and CYP2C9 in human liver microsomes with IC50s of 78.4±5.3, 81.7±2.6, and 85.1±9.1, respectively, and an even weaker inhibition against the activity of CYP2A6 in human liver microsomes with an IC50 value of more than 100 μM[4].

Ginsenosides Rd is a major compound isolated from Gynostemma pentaphyllum that holistically improves gut microenvironment and induces anti-polyposis in ApcMin/+ mice. Six-weeks-old mice are subjected to Ginsenoside Rd treatment, before the appearance of the intestinal polyps. All the mice are monitored for food intake, water consumption, and weight changes. Throughout the experiment, no Rb3/ Ginsenoside Rd-associated weight loss in mice is observed. In addition, none of the treated mice show variations in food and water consumption. Whereas, the number and size of the polyps are effectively reduced by Ginsenoside Rd treatments[3].

References:
[1]. Song SB, et al. Inhibition of TNF-α-mediated NF-κB Transcriptional Activity in HepG2 Cells by Dammarane-type Saponins from Panax ginseng Leaves. J Ginseng Res. 2012 Apr;36(2):146-52.
[2]. Liu Y, et al. Ginsenoside metabolites, rather than naturally occurring ginsenosides, lead to inhibition of human cytochrome P450 enzymes. Toxicol Sci. 2006 Jun;91(2):356-64.
[3]. Lu C, et al. Inhibition of L-type Ca2+ current by ginsenoside Rd in rat ventricular myocytes. J Ginseng Res. 2015 Apr;39(2):169-77.
[4]. Huang G, et al. Ginsenosides Rb3 and Rd reduce polyps formation while reinstate the dysbiotic gut microbiota and the intestinal microenvironment in ApcMin/+ mice. Sci Rep. 2017 Oct 2;7(1):12552.