Network Pharmacology of Red Ginseng (Part I): Effects of Ginsenoside Rg5 at Physiological and Sub-Physiological Concentrations

Numerous in vitro studies on isolated cells have been conducted to uncover the molecular mechanisms of action of Panax ginseng Meyer root extracts and purified ginsenosides. However, the concentrations of ginsenosides and the extracts used in these studies were much higher than those detected in pharmacokinetic studies in humans and animals orally administered with ginseng preparations at therapeutic doses. Our study aimed to assess: (a) the effects of ginsenoside Rg5, the major “rare” ginsenoside of Red Ginseng, on gene expression in the murine neuronal cell line HT22 in a wide range of concentrations, from 10−4 to 10−18 M, and (b) the effects of differentially expressed genes on cellular and physiological functions in organismal disorders and diseases. Gene expression profiling was performed by transcriptome-wide mRNA microarray analyses in HT22 cells after treatment with ginsenoside Rg5. Ginsenoside Rg5 exhibits soft-acting effects on gene expression of neuronal cells in a wide range of physiological concentrations and strong reversal impact at high (toxic) concentration: significant up- or downregulation of expression of about 300 genes at concentrations from 10−6 M to 10−18 M, and dramatically increased both the number of differentially expressed target genes (up to 1670) and the extent of their expression (fold changes compared to unexposed cells) at a toxic concentration of 10−4 M. Network pharmacology analyses of genes’ expression profiles using ingenuity pathway analysis (IPA) software showed that at low physiological concentrations, ginsenoside Rg5 has the potential to activate the biosynthesis of cholesterol and to exhibit predictable effects in senescence, neuroinflammation, apoptosis, and immune response, suggesting soft-acting, beneficial effects on organismal death, movement disorders, and cancer.

Network Pharmacology of Red Ginseng (Part I): Effects of Ginsenoside Rg5 at Physiological and Sub-Physiological Concentrations

Numerous in vitro studies on isolated cells have been conducted to uncover the molecular mechanisms of action of Panax ginseng Meyer root extracts and purified ginsenosides. However, the concentrations of ginsenosides and the extracts used in these studies were much higher than detected in pharmacokinetic studies in humans and animals orally administered with ginseng preparations at therapeutic doses. Our study aimed to assess: (a) the effects of ginsenoside Rg5, the major "rare" ginsenoside of Red Ginseng, on gene expression in the murine neuronal cell line HT22 in a wide range of concentrations, from 10-4 to 10-18 M, and (b) the effects of differentially expressed genes on cellular and physiological functions in organismal disorders and diseases. Gene expression profiling was performed by transcriptome-wide mRNA microarray analyses in HT22 cells after treatment with ginsenoside Rg5. Ginsenoside Rg5 exhibits soft-acting effects on gene expression of neuronal cells in a wide range of physiological concentrations and strong reversal impact at high (toxic) concentration: significant up- or downregulation of expression of about 300 genes at concentrations from 10-6 M to 10-18 M, and dramatically increased both the number of differentially expressed target genes (up to 1670) and the extent of their expression (fold changes compared to unexposed cells) at a toxic concentration of 10-4 M. Network pharmacology analyses of genes expression profiles using Ingenuity pathway analysis (IPA) software showed that at low physiological concentrations, ginsenoside Rg5 has the potential to activate the biosynthesis of cholesterol and to exhibit predictable effects in senescence, neuroinflammation, apoptosis, and immune response, suggesting soft-acting, beneficial effects on organismal death, movement disorders, and cancer.

Ginsenoside Rg5 Inhibits Human Osteosarcoma Cell Proliferation and Induces Cell Apoptosis through PI3K/Akt/mTORC1-Related LC3 Autophagy Pathway

The function and mechanism underlying the suppression of human osteosarcoma cells by ginsenoside-Rg5 (Rg5) was investigated in the present study. MG-63, HOS, and U2OS cell proliferation was determined by MTT assay after Rg5 treatment for 24 h. Rg5 inhibited human osteosarcoma cell proliferation effectively in a dose-dependent manner. The range of effective inhibitory concentrations was 160-1280 nM. Annexin V-FITC and PI double-staining assay revealed that Rg5 induced human osteosarcoma cell apoptosis. Western blotting, qRT-PCR, and FACS experiments revealed that Rg5 inhibited human osteosarcoma cells via caspase-3 activity which was related to the LC3-mediated autophagy pathway. Rg5 decreased the phosphorylation of PI3K, Akt, and mTORC1 activation. In contrast, LC3-mediated autophagy and caspase-3 activity increased significantly. A PI3K/AKT stimulator, IGF-1, reversed Rg5-induced cell autophagy and apoptosis in MG-63 cells. Collectively, the current study demonstrated that Rg5 induced human osteosarcoma cell apoptosis through the LC3-mediated autophagy pathway. Under physiological conditions, activation of PI3K/AKT/mTORC1 inhibits LC3 activity and caspase-3-related cell apoptosis. However, Rg5 activated LC3 activity by inhibiting the activation of PI3K/AKT/mTORC1. The present study indicated that Rg5 could be a promising candidate as a chemotherapeutic agent against human osteosarcoma.

An Efficient Synthesis of Ginsenoside Rg5 via Conversion of PPD Type Saponins: Unusual Application of 4A Molecular Sieves

Ginsenoside Rg5 is a rare secondary ginsenoside with good pharmacological activity. However, preparation of Rg5 is time consuming, gives a low yield and has poor selectivity and efficiency. Therefore, the current study describes an efficient method of preparing ginsenoside Rg5 through conversion of Protopanaxadiol (PPD) type saponins in the presence of a molecular sieve and hydrochloric acid. The PPD type saponins were transformed on the surface of a molecular sieve to obtain ginsenoside Rg5 and most of the generated secondary ginsenoside was dissociates into the reaction solution, avoiding further decomposition. In addition, the optimal experimental conditions were identified to be as follows; 0.5 ml of absolute ethanol, 0.2 mol/L of hydrochloric acid, 12.5 mg of a 4A molecular sieve, a reaction time of 2.5 hours and a reaction temperature of 70 ℃. Under these experimental conditions, yields of upto 63.2% were obtained for ginsenoside Rg5. Moreover, the hydrochloric acid-catalyzed preparation of ginsenoside Rg5 effectively inhibited its decomposition in the presence of a molecular sieve. The method is therefore suitable for laboratory and industrial production with the advantages of large-scale preparation and high-yield.