Effect of Ginseng Sapogenin Protopanaxadiol-Enriched Rice (DJ-PPD) on Immunomodulation

Protopanaxadiol (PPD), a gut microbiome-induced ginseng metabolite, has positive immune effects. We previously reported the immune-boosting and anti-inflammatory effects of PPD-enricshed rice seed extracts in normal and inflammatory cell environments, respectively. In the present study, the immunomodulatory activity of PPD-enriched transgenic rice seed extract (DJ-PPD), which exhibited the highest immune-related activity among all available extracts, was compared with that of commercially synthesized 20s-PPD (S-PPD) and natural ginseng root extract (GE), in RAW264.7 cells. Compared with S-PPD and GE treatment, DJ-PPD treatment (i) significantly promoted NF-κB p65 and c-Jun N-terminal protein kinase (JNK) phosphorylation; (ii) upregulated IL-1β, IL-6, COX-2, TLR-4, and TNF-α expression; (iii) and increased prostaglandin E₂ (PGE₂) production. However, there were no significant differences in the effects of the three treatments containing PPD-type sapogenin or saponins on nitric oxide (NO) production and phagocytic activity. In the inflammatory cell environment, DJ-PPD treatment markedly decreased the production of LPS-induced inflammatory factors, including NO and PGE₂, as well as proinflammatory cytokine expression, by decreasing phosphorylated (p-)NF-κB p65, p-p38 MAPK, and p-JNK levels. Thus, DJ-PPD that does not require complex intestinal microbial processes to exert higher anti-inflammatory effects compared with S-PPD and GE. However, DJ-PPD exerted similar or higher immune-boosting effects (depending on inflammatory biomarkers) than S-PPD and GE. These findings indicate the potential of PPD-enriched transgenic rice as an alternative immunomodulatory agent.

Biodistribution and pharmacokinetic evaluation of Korean Red Ginseng components using radioisotopes in a rat model

Background

Although many studies have evaluated the efficacy and pharmacokinetics of Korean Red Ginseng (KRG) components (Rg1, Rb1, Rg3, Rd, etc.), few have examined the in vivo pharmacokinetics of the radiolabeled components. This study investigated the pharmacokinetics of ginsenosides and their metabolite compound K (CK), 20(s)-protopanaxadiol (PPD), and 20(s)-protopanaxatriol (PPT) using radioisotopes in rat oral administration.

Methods

Sprague-Dawley rats were dosed orally once with 10 mg/kg of the tritium(3H) radiolabeled samples, and then the blood was collected from the tail vein after 0.25, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, 48, 96, and 168 h. Radioactivity in the organs, feces, urine, and carcass was determined using a liquid scintillation counter (LSC) and a bio-imaging analyzer system (BAS).

Results and conclusion

After oral administration, as the ³H-labeled ginsenosides were converted to metabolites, C_max and half-life increased, and T_max decreased. Interestingly, Rb1 and CK showed similar values, and after a single oral administration of components, the cumulative excretion ratio of urine and feces was 88.9%-92.4%. Although most KRG components were excreted within 96-168 h of administration, small amounts of components were detected in almost all tissues and mainly distributed to the liver except for the digestive tract when observed through autoradiography. This study demonstrated that KRG components were distributed to various organs in the rats. Further studies could be conducted to prove the bioavailability and transmission of KRG components to confirm the mechanism of KRG efficacy.

Transgenic Rice Seed Extracts Exert Immunomodulatory Effects by Modulating Immune-Related Biomarkers in RAW264.7 Macrophage Cells

Protopanaxadiol (PPD), a native active triterpenoid present in Panax ginseng, has been reported to exert immune-related effects. We previously created PPD-producing transgenic rice by introducing the P. ginseng protopanaxadiol synthase and dammarenediol-II synthase genes into Dongjin rice. In the present study, the seeds of the T₄ generation of this transgenic rice were tested for their immunomodulatory effects in RAW264.7 macrophage cells. Treatment with transgenic rice seed extract in RAW264.7 cells (i) significantly enhanced nitric oxide (NO) production in a dose-dependent manner without any cytotoxicity (up to 100 µg/mL), (ii) upregulated the expression of immune-related genes and increased production of the inflammation mediator prostaglandin E₂ (PGE₂), and (iii) activated nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) by promoting the phosphorylation of NF-κB p65, p38 MAPK, and c-Jun N-terminal protein kinase (JNK). In lipopolysaccharide (LPS)-treated RAW264.7 cells used to mimic the inflammation condition, treatment with transgenic rice seed extract significantly reduced NO production, proinflammatory cytokine expression, and PGE₂ production, all of which are LPS-induced inflammation biomarkers, by inhibiting the phosphorylation of NF-κB p65, p38 MAPK, and JNK. Collectively, these results indicate that PPD-producing transgenic rice has immunomodulatory effects.

Antioxidant and antibacterial effects of medicinal plants and their stick-type medicinal concentrated beverages

Nine medicinal plants and their stick-type medicinal concentrated beverages (SMCB-I and SMCB-II) with different combination ratio were evaluated on antioxidant, nitric oxide (NO) inhibitory, and antibacterial effects against pathogenic bacteria involved in respiratory system illnesses. Antioxidant activity was high in Syzygium aromaticum, Pueraria lobata, Plantago asiatica, and Kalopanax pictus which have higher contents of total phenolics and total flavonoids. The NO inhibitory activity was high in Syzygium aromaticum, Plantago asiatica, and Glycyrrhiza uralensis. Syzygium aromaticum, Plantago asiatica, Kalopanax pictus and Glycyrrhiza uralensis showed higher antibacterial activity than the other five medicinal plants against Staphylococcus aureus, Corynebacterium diphtheriae, and Mycobacterium sp. SMCB-II exhibited higher antioxidant, NO inhibitory, and antibacterial effects than SMCB-I, since Syzygium aromaticum, Pueraria lobata, and Kalopanax pictus were only used for the production of SMCB-II. The SMCBs would be expected to contribute to an easy-to-carry, easy-to-consume, and high value-added health beverage for the modern people.

A 20(S)-protopanaxadiol derivative PPD12 reverses ABCB1-mediated multidrug resistance with oral bioavailability and low toxicity

The ATP-binding cassette subfamily B member 1 (ABCB1) is a transporter that mediates multidrug resistance (MDR) against chemotherapy, which leads to decreased patient survival. To inhibit ABCB1 activity in MDR cancer cells, the authors previously designed and synthesized a derivative from 20(S)-protopanaxadiol (PPD) PPD12 and verified its efficacy in ABCB1-overexpressing cancer cells. In the present study, the reversal effect of PPD12 on MDR was further evaluated and its pharmacokinetics and toxicity in vitro and in vivo were investigated. Incubation with PPD12 may significantly ameliorate the drug resistance of KB/VCR cells in a short time and maintain its reversed MDR ability for increasing time periods. In assays on a series of CYP450 activities, PPD12 demonstrated slight inhibition effects on the majority of enzymes. The bioavailability of PPD12 was nearly 100% by oral administration in a mouse model. Single PPD12 oral gavage at either high doses or subchronic low doses, was well tolerated by the mice. In addition, PPD12 at the therapeutic dosage did not significantly increase the toxicity of the chemotherapeutic agent Adriamycin when mice received a combination of the two compounds. In conclusion, PPD12 represents a novel type of ABCB1 inhibitor that has significant bioactivity in terms of MDR, high oral bioavailability and low toxicity.

Simultaneous determination of 20(S)-protopanaxadiol and its three metabolites in rat plasma by LC-MS/MS: application to their pharmacokinetic studies

The aim of this study was to develop an LC-MS/MS method for simultaneous determination of 20(S) protopanaxadiol (PPD) and its three metabolites, PPD-glucuronide (M1), (20S,24S)-epoxy-dammarane-3,12,25-triol (M2) and (20S,24R)-epoxydammarane-3,12,25-triol (M3), in rat plasma. Precipitation with acetonitrile was employed for sample preparation and chromatographic separations were achieved on a C₁₈ column. The sample was detected using triple quadrupole tandem mass spectrometer with selected reaction monitoring mode. The monitored precursor-to-product ion transitions were m/z 459.4 → 375.3 for PPD, m/z 635.4 → 113.0 for M1, m/z 477.4 → 441.4 for M2 and M3 and m/z 475.4 → 391.3 for IS. The developed assay was validated according to the guidelines of the US Food and Drug Administration. The calibration curves showed good linearity over the tested concentration ranges (r > 0.9993), with the LLOQ being 1 ng/mL for all analytes. The intra- and inter-day precisions (RSD) were < 9.51% while the accuracy (RE) ranged from -8.91 to 12.84%. The extraction recovery was >80% and no obvious matrix effect was detected. The analytes were stable in rat plasma with the RE ranging from -12.34 to 9.77%. The validated assay has been successfully applied to the pharmacokinetic study of PPD as well as its metabolites in rat plasma. According to the pharmacokinetic parameters, the in vivo exposures of M1, M2 and M3 were 11.91, 47.95 and 22.62% of that of PPD, respectively.

Identification of Human UDP-Glucuronosyltransferase 1A4 as the Major Isozyme Responsible for the Glucuronidation of 20(S)-Protopanaxadiol in Human Liver Microsomes

20(S)-protopanaxadiol (PPD), one of the representative aglycones of ginsenosides, has a broad spectrum of pharmacological activities. Although phase I metabolism has been investigated extensively, information regarding phase II metabolism of this compound remains to be elucidated. Here, a glucuronidated metabolite of PPD in human liver microsomes (HLMs) and rat liver microsomes (RLMs) was unambiguously identified as PPD-3-O-β-d-glucuronide by nuclear magnetic resonance spectroscopy and high resolution mass spectrometry. The chemical inhibition and recombinant human UDP-Glucuronosyltransferase (UGT) isoforms assay showed that the PPD glucuronidation was mainly catalyzed by UGT1A4 in HLM, whereas UGT1A3 showed weak catalytic activity. In conclusion, PPD-3-O-β-d-glucuronide was first identified as the principal glucuronidation metabolite of PPD in HLMs, which was catalyzed by UGT1A4.

Metabolic profiles of 20(S)-protopanaxadiol in rats after oral administration using ultra-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry

RATIONALE

20(S)-Protopanaxadiol (PPD), a dammarane-type triterpenoid sapogenin, acts as the pharmacophore of ginsenosides which are considered as the principal bioactive components in Chinese ginseng. To fully understand the mechanism of action of PPD, it is important to study its metabolic profiles in vivo.

METHODS

Plasma, urine, fece and bile were collected after administration of PPD formulated in 0.5% aqueous Tween-80 to rats (150 mg/kg). Samples were analyzed by using a sensitive and reliable method based on ultra-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS/MS) in both positive and negative ion mode. The chemical structures of metabolites were elucidated by comparing the retention time, accurate molecular mass, and fragmentation patterns of analytes with those of PPD.

RESULTS

In total 29 metabolites, including 10 new metabolites (M20-M29), were tentatively identified and characterized. Among them, two metabolites (M3 and M4) were unambiguously identified by matching their retention times and fragmentation patterns with their standards. Principal metabolites, namely, 20, 24-oxide metabolites (M3 and M4), 26/27-carboxylic acid derivatives (M22 and M23) and a glucuronidated product (M28), were found in the rat plasma.

CONCLUSIONS

The results showed that phase I metabolites are monooxygenation, dioxygenation and oxidative dehydrogenation metabolites, and phase II metabolic pathways were demonstrated to be cysteine conjugation and glucuronidation. The newly identified metabolites are useful to understand the mechanism of elimination of PPD and, in turn, its effectiveness and toxicity.

Nutrigenomic approach to tackle the unpleasant journey to Helicobacter pylori-associated gastric carcinogenesis

While dietary habits or nutritional intake continue to rank as significant factors influencing the incidence of cancer, there have been considerable scientific uncertainties about who will benefit, but who about will not benefit from nutrition. This might be due to inadequate knowledge about an individual's genetic background, the cumulative effect of nutrients on genetic expression profiles, ambiguous clinical differences between beneficiaries and non-beneficiaries and the lack of information about active protein induction. During the past 200 years of nutrition research, we have experienced revolutionary advances in both chemistry and genomics. According to the high expectations for tailored medicine, a nutrigenomic approach harboring tremendous potential to change the future of dietary guideline and personal recommendations will provide an essential basis for personalized dietary recommendations to prevent common multifactorial diseases decades before their overt clinical manifestation. In the current review, we introduce our efforts to discover Helicobacter pylori (H. pylori)-related disease biomarkers applicable for diagnostic, predictive and therapeutic purposes using several kinds of technology. For instance, based on publications showing the in vitro and in vivo efficacy of Korean red ginseng on mitigating H. pylori-associated gastric atrophy, a nutrigenomic approach allows us to confirm that Korean red ginseng prevents H. pylori-associated gastric cancer in predictable ways.

Identification of 20(S)-protopanaxadiol metabolites in human liver microsomes and human hepatocytes

20(S)-Protopanaxadiol (PPD, 1) is one of the aglycones of the ginsenosides and has a wide range of pharmacological activities. At present, PPD has progressed to early clinical trials as an antidepressant. In this study, its fate in mixed human liver microsomes (HLMs) and human hepatocytes was examined for the first time. By using liquid chromatography-electrospray ionization ion trap mass spectrometry, 24 metabolites were found. Four metabolites were isolated, and their structures were elucidated as (20S,24S)-epoxydammarane-3,12,25-triol (2), (20S,24R)-epoxydammarane-3,12,25-triol (3), (20S,24S)-epoxydammarane-12,25-diol-3-one (4), and (20S,24R)-epoxydammarane-12,25-diol-3-one (5) based on a detailed analysis of their spectroscopic data. The predominant metabolic pathway of PPD observed was the oxidation of the 24,25-double bond to yield 24,25-epoxides, followed by hydrolysis and rearrangement to form the corresponding 24,25-vicinal diol derivatives (M6) and the 20,24-oxide form (2 and 3). Further sequential metabolites (M2-M5) were also detected through the hydroxylation and dehydrogenation of 2 and 3. All of the phase I metabolites except for M1-1 possess a hydroxyl group at C-25 of the side chain, which was newly formed by biotransformation. Two glucuronide conjugates (M7) attributed to 2 and 3 were detected in human hepatocyte incubations, and their conjugation sites were tentatively assigned to the 25-hydroxyl group. The findings of this study strongly suggested that the formation of the 25-hydroxyl group is very important for the elimination of PPD.

Progression from chronic atrophic gastritis to gastric cancer; tangle, toggle, tackle with Korea red ginseng

Key molecular players that link inflammation to carcinogenesis are prostaglandins, cytokines, nuclear factor-κB (NF-κB), chemokines, angiogenic growth factors, and free radicals, all of which lead to increased mutations and altered functions of important enzymes and proteins, for example, activation of oncogenic products and/or inhibition of tumor suppressor proteins, in inflamed tissues, thus contributing to multi-stage carcinogenesis process. Interpreted reversely, the identification of the molecular mechanisms by which chronic inflammation increases cancer risk or optimal intervention of targeted drugs or agents during the inflammation-associated carcinogenic process could be a necessary basis for developing new strategy of cancer prevention at many sites. In this review, we discuss the possibilities for cancer prevention by controlling inflammation process in Helicobacter pylori (H. pylori)-associated inflamed stomach with Korea red ginseng. Korea red ginseng is a good example of a natural herb that has ubiquitous properties that are conductive to stop inflammatory carcinogenesis that is un wanted outcome of H. pylori infection, rendering rejuvenation of chronic atrophic gastritis.