Dong-Uk Yang

Ginseng saponins and the treatment of osteoporosis: mini literature review

The ginseng plant (Panax ginseng Meyer) has a large number of active ingredients including steroidal saponins with a dammarane skeleton as well as protopanaxadiol and protopanaxatriol, commonly known as ginsenosides, which have antioxidant, anticancer, antidiabetic, anti-adipocyte, and sexual enhancing effects. Though several discoveries have demonstrated that ginseng saponins (ginsenosides) as the most important therapeutic agent for the treatment of osteoporosis, yet the molecular mechanism of its active metabolites is unknown. In this review, we summarize the evidence supporting the therapeutic properties of ginsenosides both in vivo and in vitro, with an emphasis on the different molecular agents comprising receptor activator of nuclear factor kappa-B ligand, receptor activator of nuclear factor kappa-B, and matrix metallopeptidase-9, as well as the bone morphogenetic protein-2 and Smad signaling pathways.

Biotransformation of Ginsenoside Rb 1 to Prosapogenins, Gypenoside XVII, Ginsenoside Rd, Ginsenoside F 2 , and Compound K by Leuconostoc mesenteroides DC102

Ginsenoside Rb1is the main component in ginsenosides. It is a protopanaxadiol-type ginsenoside that has a dammarane-type triterpenoid as an aglycone. In this study, ginsenoside Rb1 was transformed into gypenoside XVII, ginsenoside Rd, ginsenoside F2 and compound K by glycosidase from Leuconostoc mesenteroides DC102. The optimum time for the conversion was about 72 h at a constant pH of 6.0 to 8.0 and the optimum temperature was about 30℃. Under optimal conditions, ginsenoside Rb1 was decomposed and converted into compound K by 72 h post-reaction (99%). The enzymatic reaction was analyzed by highperformance liquid chromatography, suggesting the transformation pathway: ginsenoside Rb1→ gypenoside XVII and ginsenoside Rd→ginsenoside F2→compound K.

Molecular docking studies of anti-apoptotic BCL-2, BCL-XL, and MCL-1 proteins with ginsenosides from Panax ginseng

Anti-apoptotic proteins such as BCL-2, BCL-XL and MCL-1 bind with pro-apoptotic proteins to induce apoptosis mechanism. BCL-2 family proteins are key regulators of apoptosis process. Over expression of these anti-apoptotic proteins lead to several cancers by preventing apoptosis. A number of studies revealed that ginseng derivatives reduce tumor growth. Ginseng, the most valuable medicinal herb found in eastern Asia belongs to Araliaceae family. In this study, docking simulations were performed for anti-apoptotic proteins with several ginsenosides from Panax ginseng. Our finding shows ginsenosides Rf, Rg1, Rg3 and Rh2 have more binding affinity with BCL-2, BCL-XL and MCL-1 and other ginsenosides also interact with each anti-apoptotic proteins. Therefore, ginseng derivatives represent a novel class of potent inhibitors and could be used for cancer chemotherapy.

Enzymatic Transformation of Ginsenoside Rb1 by Lactobacillus pentosus Strain 6105 from Kimchi

Ginsenoside (ginseng saponin), the principal component of ginseng, is responsible for the pharmacological and biological activities of ginseng. We isolated lactic acid bacteria from Kimchi using esculin agar, to produce β-glucosidase. We focused on the bio-transformation of ginsenoside. Phylogenetic analysis was performed by comparing the 16S rRNA sequences. We identified the strain as Lactobacillus (strain 6105). In order to determine the optimal conditions for enzyme activity, the crude enzyme was incubated with 1 mM ginsenoside Rb1 to catalyse the reaction. A carbon substrate, such as cellobiose, lactose, and sucrose, resulted in the highest yields of β-glucosidase activity. Biotransformations of ginsenoside Rb1 were analyzed using TLC and HPLC. Our results confirmed that the microbial enzyme of strain 6105 significantly transformed ginsenoside as follows: Rb1→gypenoside XVII, Rd→F2 into compound K. Our results indicate that this is the best possible way to obtain specific ginsenosides using microbial enzymes from 6105 culture.

Bioconversion of ginsenoside Rb1 into compound K by Leuconostoc citreum LH1 isolated from kimchi

About 40 different types of ginsenoside (ginseng saponin), a major pharmacological component of ginseng, have been identified along with their physiological activities. Among these, compound K has been reported to prevent the development of and the metastasis of cancer by blocking the formation of tumors and suppressing the invasion of cancerous cells. In this study, ginsenoside Rb1 was converted into compound K via interaction with the enzyme secreted by β-glucosidase active bacteria, Leuconostoc citreum LH1, extracted from kimchi. The optimum time for the conversion of Rb1 to compound K was about 72 hrs at a constant pH of 6.0 and an optimum temperature of about 30oC. Under optimal conditions, ginsenoside Rb1 was decomposed and converted into compound K by 72 hrs post-reaction (99%). Both TLC and HPLC were used to analyze the enzymatic reaction. Ginsenoside Rb1 was consecutively converted to ginsenoside Rd, F2, and compound K via the hydrolyses of 20-C β-(1 → 6)-glucoside, 3-C β-(1 → 2)glucoside, and 3-C β-glucose of ginsenoside Rb1.

Stimulative Effect of Ginsenosides Rg5:Rk1 on Murine Osteoblastic MC3T3‐E1 Cells

Panax ginseng C.A. Meyer (P. ginseng), hereafter referred to as P. ginseng, is known to exert a wide range of pharmacological effects both in vitro and in vivo; however, few studies have investigated the effects of ginseng on bone metabolism. We therefore investigated the potential antiosteoporotic properties of ginseng on the growth and differentiation of murine MC3T3‐E1 cells. Rg5:Rk1 is a mixture of protopanaxadiol‐type ginsenosides, isolated from fresh P. ginseng root, via a repetitive steaming and drying process. In this study, we examined the stimulatory effects of Rg5:Rk1 on the differentiation and mineralization of MC3T3‐E1 cells. Undifferentiated cells were treated with a range of concentrations of Rg5:Rk1 (1–50 µg/mL), and cell viability was measured with the 3‐(4,5‐dimethyl‐thiazol‐2yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay. Treatment with Rg5:Rk1 significantly increased cell viability in a dose‐dependent manner. To investigate the possible mechanisms by which Rg5:Rk1 affects the early differentiation phase of MC3T3‐E1 cells, the cells were treated with Rg5:Rk1 for 14–24 days before assessing the levels of multiple osteoblastic markers. The markers examined included alkaline phosphatase (ALP) activity type I collagen content (Coll‐I), calcium deposition (by Alizarin Red S staining), extracellular mRNA expression of bone morphogenetic protein‐2 (BMP‐2), and the level of Runt‐related transcription factor 2 (Runx2). Rg5:Rk1 treatment also increased the activities of proteins associated with osteoblast growth and differentiation in a dose‐dependent manner. Overall, we found that the Rg5:Rk1 mixture of ginsenosides improved the osteoblastic function of MC3T3‐E1 cells by increasing their proliferative capacity. This improvement is due to the action of Rg5:Rk1 on BMP‐2, which is mediated by Runx2‐dependent pathways. Copyright

Classification and characterization of putative cytochrome P450 genes from Panax ginseng C. A. Meyer

In plants heme containing cytochrome P450 (P450) is a superfamily of monooxygenases that catalyze the addition of one oxygen atom from O2 into a substrate, with a substantial reduction of the other atom to water. The function of P450 families is attributed to chemical defense mechanism under terrestrial environmental conditions; several are involved in secondary and hormone metabolism. However, the evolutionary relationships of P450 genes in Panax ginseng remain largely unknown. In the present study, data mining methods were implemented and 116 novel putative P450 genes were identified from Expressed Sequence Tags (ESTs) of a ginseng database. These genes were classified into four clans and 22 families by sequence similarity conducted at amino acid level. The representative putative P450 sequences of P. ginseng and known P450 family from other plants were used to construct a phylogenetic tree. By comparing with other genomes, we found that most of the P450 genes from P. ginseng can be found in other dicot species. Depending on P450 family functions, seven P450 genes were selected, and for that organ specific expression, abiotic, and biotic studies were performed by quantitative reverse transcriptase-polymerase chain reaction. Different genes were found to be expressed differently in different organs. Biotic stress and abiotic stress transcript level was regulated diversely, and upregulation of P450 genes indicated the involvement of certain genes under stress conditions. The upregulation of the P450 genes under methyl jasmonate and fungal stress justifies the involvement of specific genes in secondary metabolite biosynthesis. Our results provide a foundation for further elucidating the actual function and role of P450 involved in various biochemical pathways in P. ginseng.

Gallbladder carcinoma: causes of misdiagnosis at CT

Gallbladder carcinomas can present with varied imaging features on computed tomography. The three major imaging features include (1) focal or diffuse wall thickening with or without irregularity of the gallbladder; (2) polypoidal intraluminal mass; and (3) large mass obscuring and replacing the gallbladder, often extending to the liver. Patterns of wall thickening or polypoid growth are often confused with various benign gallbladder diseases due to overlap of imaging findings. Moreover, gallbladder carcinomas that coexist with benign gallbladder diseases make accurate preoperative diagnosis more difficult. Recently, high-resolution ultrasound (HRUS) has been regarded as a problem-solving tool for gallbladder diseases. In this article, we will illustrate various imaging presentations of gallbladder cancer, along with imaging pitfalls and recently updated HRUS findings.

Development of a single-nucleotide-polymorphism marker for specific authentication of Korean ginseng (Panax ginseng Meyer) new cultivar “G-1”

Background Korean ginseng (Panax ginseng) is a well-known medicinal plant of Oriental medicine that is still in practice today. Until now, a total of 11 Korean ginseng cultivars with unique features to Korean ginseng have been developed based on the pure-line-selection method. Among them, a new cultivar namely G-1 with different agricultural traits related to yield and content of ginsenosides, was developed in 2012. Methods The aim of this study was to distinguish the new ginseng cultivar G-1 by identifying the unique single-nucleotide polymorphism (SNP) at its 45S ribosomal DNA and Panax quinquefolius region than other Korean ginseng cultivars using multiplex amplification-refractory mutation system–polymerase chain reaction (ARMS-PCR). Results A SNP at position of 45S ribosomal DNA region between G-1, P. quinquefolius, and the other Korean ginseng cultivars was identified. By designing modified allele-specific primers based on this site, we could specifically identified G-1 and P. quinquefolius via multiplex PCR. The unique primer for the SNP yielded an amplicon of size 449 bp in G-1 cultivar and P. quinquefolius. This study presents an effective method for the genetic identification of the G-1 cultivar and P. quinquefolius. Conclusion The results from our study shows that this SNP-based approach to identify the G-1 cultivar will be a good way to distinguish accurately the G-1 cultivar and P. quinquefolius from other Korean ginseng cultivars using a SNP at 45S ribosomal DNA region.

Development of a multiplex amplification refractory mutation system for simultaneous authentication of Korean ginseng cultivars “Gumpoong” and “Chungsun”

Background and aims. Molecular authentication of Korean ginseng cultivars was investigated using the mitochondrial nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit 7 (nad7) intron 3 region. Materials and methods. A mutation site specific to Panax ginseng “Gumpoong” and “Chungsun” cultivars was detected within the sequence data. Based on this mutation site and the “Gumpoong”-specific single nucleotide polymorphism site reported in 26S rDNA, two modified allele-specific primer pairs were designed and a multiplex amplification refractory mutation system (MARMS) was applied to identify “Gumpoong” and “Chungsun.” Results. The results showed that “Gumpoong” and “Chungsun” can be clearly discriminated from the other Korean ginseng cultivars by simultaneously identifying the haplotype of “Gumpoong” and the specific allele of “Chungsun” by applying the MARMS. Conclusion. This study, therefore, provides a simple and reliable method for simultaneous authentication of “Gumpoong” and “Chungsun” cultivars.