Anti-tumor-promoting activity of majonoside-R2 from Vietnamese ginseng, Panax vietnamensis Ha et Grushv. (I)

Genetic population structure of the Vietnamese ginseng (Panax vietnamensis Ha et Grushv.) detected by microsatellite analysis

Abstract Panax vietnamensis Ha et Grushv. is a precious medicinal species native to the tropical forests of Vietnam. Due to habitat loss and over-harvesting, this species is endangered in Vietnam. To conserve the species, we investigated genetic variability and population structure using nine microsatellites for 148 individuals from seven populations across the current distribution range of P. vietnamensis in Vietnam. We determined a moderate genetic diversity within populations (HO = 0.367, HE = 0.437) and relatively low population differentiation (the Weir and Cockerham index of 0.172 and the Hedrick index of 0.254) and showed significant differentiation (P < 0.05), which suggested fragmented habitats, over-utilization and over-harvesting of P. vietnamensis. Different clustering methods revealed that individuals were grouped into two major clusters, which were associated with gene flow across the geographical range of P. vietnamensis. This study also detected that ginseng populations can have undergone a recent bottleneck. We recommend measures in future P. vietnamensis conservation and breeding programs.

Application of Coating Chitosan Derivatives (N,O-Carboxymethyl Chitosan/Chitosan Oligomer Saccharide) in Combination with Polyvinyl Alcohol Solutions to Preserve Fresh Ngoc Linh Ginseng Quality

The postharvest preservation of Ngoc Linh ginseng (NL ginseng) is essential to retain its quality and sensory values for prolonged storage. In this study, the efficacy of NL ginseng preservation by coating chitosan derivatives in combination with polyvinyl alcohol (PVA) solutions was investigated under refrigeration conditions (~3 °C; ~40% RH) for 56 days. The effect of the chitosan-based solutions, including N,O-carboxymethyl chitosan (NOCC), chitosan oligomer saccharide (COS), or chitosan (CS), and the blend solutions (NOCC-PVA or COS-PVA) on the coated NL ginsengs was observed during storage. The pH values, viscosity, and film-forming capability of the coating solutions were determined, while the visual appearance, morphology, and mechanical properties of the films formed on glass substrates as a ginseng model for coating were also observed. The appearance, skin lightness, weight loss, sensory evaluation, total saponin content (TSC), total polyphenol content (TPC), and total antioxidant capacity (TAC) of the coated NL ginsengs were evaluated. The findings showed that the observed values of the coated NL ginsengs were better than those of the non-coated samples, with the exception of the COS-coated samples, which had completely negative results. Furthermore, the NOCC-PVA solution exhibited a better preservation effect compared with the COS-PVA one based on the observed indices, except for TPC and TAC, which were not impacted by the coating. Notably, the optimal preservation time was determined to be 35 days. This study presents promising preservation technology using the coating solution of NOCC-PVA, harnessing the synergistic effect of pH 7.4 and the form-firming capacity, to maintain the shelf life, medicinal content, and sensory attributes of NL ginseng.

Untargeted Metabolomics Approach for the Differentiation between Panax vietnamensis var. vietnamensis and Panax vietnamensis var. fuscidiscus

Panax vietnamensis var. vietnamensis (PVV) and Panax vietnamensis var. fuscidiscus (PVF) both belong to Panax vietnamensis species and are chemically and morphologically similar, making it hard to distinguish for the consumer. Herein, 42 PVF and 12 PVV samples were collected in Quang Nam and Lai Chau Province, respectively, and subsequently characterized by ITSr-DNA sequence data to verify their origins. Next, untargeted metabolomics combined with multivariate statistical analysis was developed to differentiate PVV and PVF. The metabolic profiles of PVV and PVF were found to be distinct and classified well using Partial Least-Squares Discriminant Analysis (PLS-DA) in the training set. Among them, seven ginsenosides were of high abundance in PVV, while six were of high abundance in PVF. Next, the test set was used to validate 13 putative differential markers found in the training set, illustrating a complete match with the expression patterns of these ginsenosides in the training set. Finally, PLS-DA and linear Support Vector Machine models both indicated distinct ginsenoside profiles of PVV and PVF without misclassification in the test set. Conclusively, the developed untargeted metabolomics approach might serve as a powerful tool for the authentication of PVV and PVF at the metabolome level.

Research progress on naturally-occurring and semi-synthetic ocotillol-type ginsenosides in the genus Panax L. (Araliaceae)

Ocotillol (OT)-type ginsenosides, one subtype of ginsenosides, consist of a dammarane skeleton and a tetrahydrofuran ring. Most naturally-occurring OT-type ginsenosides exist in Panax species, particularly in Panax quinquefolius, which may be attributed to the warm and humid climate of its native areas. Till now, merely 28 types of naturally-occurring OT-type ginsenosides have been isolated. In contrast, semi-synthesized OT-type ginsenosides are attracted considerable attentions. These ginsenosides can be obtained through oxidation and cyclization of side chains of dammarane-type ginsenosides, and other methods, which may change their physical and chemical properties and further improve their bioavailabilities. It is also notable that the pharmacological activities of ginsenosides are closely related to the stereoisomers caused by the configuration at C-20. Semi-synthesis of OT-type ginsenosides can facilitate our understanding of the biosynthesis, transformation and metabolism of OT-type ginsenosides in the body. This review will systematically summarize the research progress on naturally-occurring and semi-synthetic OT-type ginsenosides, which provides a theoretical basis for their bioactivity-guided research.

Evaluation of the Saponin Content in Panax vietnamensis Acclimatized to Lam Dong Province by HPLC-UV/CAD

Panax vietnamensis, or Vietnamese ginseng (VG), an endemic Panax species in Vietnam, possesses a unique saponin profile and interesting biological activities. This plant is presently in danger of extinction due to over-exploitation, resulting in many preservation efforts towards the geographical acclimatization of VG. Yet, no information on the saponin content of the acclimatized VG, an important quality indicator, is available. Here, we analyzed the saponin content in the underground parts of two- to five-year-old VG plants acclimatized to Lam Dong province. Nine characteristic saponins, including notoginsenoside-R1, ginsenoside-Rg1, -Rb1, -Rd, majonoside-R1, -R2 vina-ginsenoside-R2, -R11, and pseudoginsenoside-RT4, were simultaneously determined by HPLC coupled with UV and with a charged aerosol detector (CAD). Analyzing the results illustrated that the detection of characteristic ocotillol-type saponins in VG by CAD presented a superior capacity compared with that of UV, thus implying a preferential choice of CAD for the analysis of VG. The quantitative results indicating the saponin content in the underground parts of VG showed an increasing tendency from two to five years old, with the root and the rhizome exhibiting different saponin accumulation patterns. This is the first study that reveals the preliminary success of VG acclimatization and thereby encourages the continuing efforts to develop this valuable saponin-rich plant.

Synthesis and Anti-Hepatocarcinoma Effect of Amino Acid Derivatives of Pyxinol and Ocotillol

Aiming at seeking an effective anti-hepatocarcinoma drug with low toxicity, a total of 24 amino acid derivatives (20 new along with 4 known derivatives) of two active ocotillol-type sapogenins (pyxinol and ocotillol) were synthesized. Both in vitro and in vivo anti-hepatocarcinoma effects of derivatives were evaluated. At first, the HepG2 human cancer cell was employed to evaluate the anti-cancer activity. Most of the derivatives showed obvious enhanced activity compared with pyxinol or ocotillol. Among them, compound 2e displayed the most excellent activity with an IC₅₀ value of 11.26 ± 0.43 µM. Next, H22 hepatoma-bearing mice were used to further evaluate the anti-liver cancer activity of compound 2e. It was revealed that the growth of H22 transplanted tumor was significantly inhibited when treated with compound 2e or compound 2e combined with cyclophosphamide (CTX) (p < 0.05, p < 0.01), and the inhibition rates of tumor growth were 35.32% and 55.30%, respectively. More importantly, compound 2e caused limited damage to liver and kidney in contrast with CTX causing significant toxicity. Finally, the latent mechanism of compound 2e was explored by serum and liver metabolomics based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) technology. A total of 21 potential metabolites involved in 8 pathways were identified. These results suggest that compound 2e is a promising agent for anti-hepato-carcinoma, and that it also could be used in combination with CTX to increase efficiency and to reduce toxicity.

The crystal structure of (3S,8R,10R,14R)-17-((2S,5S)-5-(2-hydroxypropan-2-yl)-2-methyltetrahydrofuran-2-yl)-4,4,8,10,14-pentamethyl-12-oxohexadecahydro-1H-cyclopenta[a]phenanthren-3-yl acetate, C32H52O5

C32H52O5, monoclinic, P21 (no. 4), a = 11.816(2) Å, b = 7.4064(15) Å, c = 17.101(3) Å, β = 97.01(3)°, V = 1485.5(5) Å3, Z = 2, R gt(F) = 0.0543, wR ref(F 2) = 0.1501, T = 293(2) K.

Accumulation of Saponins in Underground Parts of Panax vietnamensis at Different Ages Analyzed by HPLC-UV/ELSD

Panax vietnamensis (PV), a wild Panax species discovered in Vietnam in 1973, has been increasingly overexploited due to its economic value and therapeutic uses. This resulted in the development of PV cultivation to meet the market demand. There is little information on the accumulation of saponins in PV during cultivation, but this information could serve as an indication of the appropriate harvest time. In this study we developed an HPLC-UV/ELSD method to simultaneously determine the content of 10 characteristic saponins in PV from 2–7 years old, including G-Rb1, G-Rd, G-Rg1, G-Re, N-R1, M-R1, M-R2, V-R2, V-R11, and p-RT4. The result indicated that from 2 to 5 years, the content of saponins in PV rhizome and radix increase 3.02 and 4.2 times, respectively, whereas from 5 to 7 years, no significant changes were observed. Hence, our study suggests that after 5 years of growth could be considered as an appropriate time for PV to be harvested. Among the analyzed saponins, G-Rg1, G-Rb1, G-Rd, and especially M-R2 were the major saponins that contributed to the change of PV’s saponin content through the years. In addition, the developed and validated HPLC method was proven to be reliable and effective for quality control of PV.

Characteristics of Panax ginseng Cultivars in Korea and China

Ginseng (Panax ginseng Meyer) is one of the most important medicinal herbs in Asia. Its pharmacological activity comes from ginsenosides, and its roots are produced commercially for traditional and Oriental medicine. Though 17 Panax species are available around the world, there was a need to develop cultivars adapted to different climatic conditions and resistant to various diseases while still producing high-quality, high-yield roots. Thus, 12 and 9 commercial P. ginseng cultivars have been registered in South Korea and China, respectively. Those varieties show superiority to local landraces. For example, Chunpoong is more highly resistant to rusty rot disease than the local Jakyungjong landrace and has a good root shape; it is highly cultivated to produce red ginseng. The Chinese cultivar Jilin Huangguo Renshen has higher ginsenoside content than its local landraces. This review provides information about P. ginseng cultivars and offers directions for future research, such as intra- and interspecific hybridization.

Korean red ginseng promotes hippocampal neurogenesis in mice

Neurogenesis in the adult hippocampus plays a major role in cognitive ability of animals including learning and memory. Korean red ginseng (KRG) has long been known as a medicinal herb with the potential to improve learning and memory; however, the mechanisms are still elusive. Therefore, we evaluated whether KRG can promote cognitive function and enhance neurogenesis in the hippocampus. Eight-week-old male C57BL/6 mice received 50 mg/kg of 5-bromo-2'-deoxyuridine (BrdU) intraperitoneally and 100 mg/kg of KRG or vehicle orally once a day for 14 days. Pole, Rotarod and Morris water maze tests were performed and the brains were collected after the last behavioral test. Changes in the numbers of BrdU- and BrdU/doublecortin (DCX; a marker for neuronal precursor cells and immature neurons)-positive cells in the dentate gyrus and the gene expression of proliferating cell nuclear antigen (a marker for cell differentiation), cerebral dopamine neurotrophic factor and ciliary neurotrophic factor in the hippocampus were then investigated. KRG-treated mice came down the pole significantly faster and stood on the rotarod longer than vehicle-treated mice. The Morris water maze test showed that KRG administration enhanced the learning and memory abilities significantly. KRG also significantly increased BrdU- and BrdU/DCX-positive cells in the dentate gyrus as well as the proliferating cell nuclear antigen, cerebral dopamine neurotrophic factor and ciliary neurotrophic factor mRNA expression levels in the hippocampus compared to vehicle. Administration of KRG promotes learning and memory abilities, possibly by enhancing hippocampal neurogenesis. This study was approved by the Pusan National University Institutional Animal Care and Use Committee (approval No. PNU-2016-1071) on January 19, 2016.

Increase in Protective Effect of Panax vietnamensis by Heat Processing on Cisplatin-Induced Kidney Cell Toxicity

Cisplatin is a platinum-based anticancer agent used for treating a wide range of solid cancers. One of the side effects of this drug is its severe nephrotoxicity, limiting the safe dose of cisplatin. Therefore, many natural products have been studied and applied to attenuate the toxicity of this compound. In this study, we found that steamed Vietnamese ginseng (Panax vietnamensis) could significantly reduce the kidney damage of cisplatin in an in vitro model using porcine proximal tubular LLC-PK1 kidney cells. From processed ginseng under optimized conditions (120 °C, 12 h), we isolated seven compounds (20(R,S)-ginsenoside Rh2, 20(R,S)-ginsenoside Rg3, ginsenoside Rk1, ginsenoside-Rg5, and ocotillol genin) that showed kidney-protective potential against cisplatin toxicity. By comparing the 50% recovery concentration (RC₅₀), the R form of ginsenoside, Rh2 and Rg3, had RC₅₀ values of 6.67 ± 0.42 µM and 8.39 ± 0.3 µM, respectively, while the S forms of ginsenoside, Rh2 and Rg3, and Rk1, had weaker protective effects, with RC₅₀ ranging from 46.15 to 88.4 µM. G-Rg5 and ocotillol, the typical saponin of Vietnamese ginseng, had the highest RC₅₀ (180.83 ± 33.27; 226.19 ± 66.16, respectively). Our results suggest that processed Vietnamese gingseng (PVG), as well as those compounds, has the potential to improve kidney damage due to cisplatin toxicity.

Synthesis of Ocotillol-Type Ginsenosides

A total of 14 ocotillol-type ginsenosides were conveniently synthesized employing glycosylation of ocotillol sapogenin derivatives with glucosyl ortho-alkynylbenzoate donors under the promotion of a gold(I) catalyst as the key step. Relying on a rational protecting group strategy and the unexpected regioselectivity of the glycosylation of the 3,25-diol sapogenins (2a/2b, 5a/5b) for the tertiary 25-OH, mono 3-O-glucosyl ocotillol-PPD, 6-O-glucosyl ocotillol-PPT, 25-O-glucosyl ocotillol-PPD/PPT and 3,25-di-O-glucosyl ocotillol-PPD/PPT ginsenosides were prepared in which the configuration at the C-24 is either R or S.

Transcriptome analysis of Panax vietnamensis var. fuscidicus discovers putative ocotillol-type ginsenosides biosynthesis genes and genetic markers

BACKGROUND

P. vietnamensis var. fuscidiscus, called "Yesanqi" in Chinese, is a new variety of P. vietnamensis, which was first found in Jinping County, the southern part of Yunnan Province, China. Compared with other Panax plants, this species contains higher content of ocotillol-type saponin, majonoside R2. Despite the pharmacological importance of ocotillol-type saponins, little is known about their biosynthesis in plants. Hence, P. vietnamensis var. fuscidiscus is a suitable medicinal herbal plant species to study biosynthesis of ocotillol-type saponins. In addition, the available genomic information of this important herbal plant is lacking.

RESULTS

To investigate the P. vietnamensis var. fuscidiscus transcriptome, Illumina HiSeq™ 2000 sequencing platform was employed. We produced 114,703,210 clean reads, assembled into 126,758 unigenes, with an average length of 1,304 bp and N50 of 2,108 bp. Among these 126,758 unigenes, 85,214 unigenes (67.23%) were annotated based on the information available from the public databases. The transcripts encoding the known enzymes involved in triterpenoid saponins biosynthesis were identified in our Illumina dataset. A full-length cDNA of three Squalene epoxidase (SE) genes were obtained using reverse transcription PCR (RT-PCR) and the expression patterns of ten unigenes were analyzed by reverse transcription quantitative real-time PCR (RT-qPCR). Furthermore, 15 candidate cytochrome P450 genes and 17 candidate UDP-glycosyltransferase genes most likely to involve in triterpenoid saponins biosynthesis pathway were discovered from transcriptome sequencing of P. vietnamensis var. fuscidiscus. We further analyzed the data and found 21,320 simple sequence repeats (SSRs), 30 primer pairs for SSRs were randomly selected for validation of the amplification and polymorphism in 13 P. vietnamensis var. fuscidiscus accessions. Meanwhile, five major triterpene saponins in roots of P. vietnamensis var. fuscidicus were determined using high performance liquid chromatography (HPLC) and evaporative light scattering detector (ELSD).

CONCLUSIONS

The genomic resources generated from P. vietnamensis var. fuscidiscus provide new insights into the identification of putative genes involved in triterpenoid saponins biosynthesis pathway. This will facilitate our understanding of the biosynthesis of triterpenoid saponins at molecular level. The SSR markers identified and developed in this study show genetic diversity for this important crop and will contribute to marker-assisted breeding for P. vietnamensis var. fuscidiscus.

Administration of red ginseng ameliorates memory decline in aged mice

Background

It has been known that ginseng can be applied as a potential nutraceutical for memory impairment; however, experiments with animals of old age are few.

Methods

To determine the memory enhancing effect of red ginseng, C57BL/6 mice (21 mo old) were given experimental diet pellets containing 0.12% red ginseng extract (approximately 200 mg/kg/d) for 3 mo. Young and old mice (4 mo and 21 mo old, respectively) were used as the control group. The effect of red ginseng, which ameliorated memory impairment in aged mice, was quantified using Y-maze test, novel objective test, and Morris water maze. Red ginseng ameliorated age-related declines in learning and memory in older mice. In addition, red ginseng's effect on the induction of inducible nitric oxide synthase and proinflammatory cytokines was investigated in the hippocampus of aged mice.

Results

Red ginseng treatment suppressed the production of age-processed inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, and interleukin-1β expressions. Moreover, it was observed that red ginseng had an antioxidative effect on aged mice. The suppressed glutathione level in aged mice was restored with red ginseng treatment. The antioxidative-related enzymes Nrf2 and HO-1 were increased with red ginseng treatment.

Conclusion

The results revealed that when red ginseng is administered over long periods, age-related decline of learning and memory is ameliorated through anti-inflammatory activity.

Protective effect of Korean Red Ginseng against glucocorticoid-induced osteoporosis in vitro and in vivo

Background

Glucocorticoids (GCs) are commonly used in many chemotherapeutic protocols and play an important role in the normal regulation of bone remodeling. However, the prolonged use of GCs results in osteoporosis, which is partially due to apoptosis of osteoblasts and osteocytes. In this study, effects of Korean Red Ginseng (KRG) on GC-treated murine osteoblastic MC3T3-E1 cells and a GC-induced osteoporosis mouse model were investigated.

Methods

MC3T3-E1 cells were exposed to dexamethasone (Dex) with or without KRG and cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Real-time polymerase chain reaction was performed to evaluate the apoptotic gene expression; osteogenic gene expression and alkaline phosphatase (ALP) activity were also measured. Western blotting was performed to evaluate the mitogen-activated protein kinase (MAPK) proteins. A GC-induced osteoporosis animal model was used for in vivo study.

Results and conclusion

The MTT assay revealed that Korean Red Ginseng (KRG) prevents loss of cell viability caused by Dex-induced apoptosis in MC3T3E1 cells. Real-time polymerase chain reaction data showed that groups treated with both Dex and KRG exhibited lower mRNA levels of caspase-3 and -9, whereas the mRNA levels of Bcl2, IAPs, and XIAP increased. Moreover, groups treated with both Dex and KRG demonstrated increased mRNA levels of ALP, RUNX2, and bone morphogenic proteins as well as increased ALP activity in MC3T3-E1 cells, compared to cells treated with Dex only. In addition, KRG increased protein kinase B (AKT) phosphorylation and decreased c-Jun N-terminal kinase (JNK) phosphorylation. Moreover, microcomputed tomography analysis of the femurs showed that GC implantation caused trabecular bone loss. However, a significant reduction of bone loss was observed in the KRG-treated group. These results suggest that the molecular mechanism of KRG in the GC-induced apoptosis may lead to the development of therapeutic strategies to prevent and/or delay osteoporosis.

Enhancement of anti-inflammatory and antinociceptive actions of red ginseng extract by fermentation

Objectives

This work aimed to compare some pharmacological properties of red ginseng extract (RG) and fermented red ginseng extract (FRG).

Methods

Antinociceptive activity was analysed using the acetic acid-induced abdominal constriction response. Anti-inflammatory activity was evaluated using acetic acid-induced vascular permeability and carrageenan-induced inflammation in the air pouch, and analysed through the measurement of nitrite content in the lipopolysaccharide (LPS)-stimulated macrophage cells. Anti-angiogenic activity was determined using the chick chorioallantoic membrane assay.

Key findings

In-vivo anti-inflammatory activity of FRG was stronger than that of RG in two animal models, vascular permeability and air-pouch models. In the vascular permeability model, the doses of RG and FRG required for half-maximal inhibition (IC50) were 181 and 59 mg/kg, respectively. FRG exhibited significantly stronger antinociceptive activity than RG. In the acetic acid-induced abdominal constriction response, the IC50 values of RG and FRG were 153 and 27 mg/kg, respectively. Although both RG and FRG were able to suppress production of nitric oxide in the LPS-stimulated RAW264.7 macrophage cells, the suppressive activity of FRG appeared to be stronger than that of RG. However, RG and FRG showed similar anti-angiogenic activity.

Conclusions

FRG possesses enhanced anti-inflammatory and antinociceptive activity but similar anti-angiogenic activity than RG.

Protective effects of a gastrointestinal agent containing Korean red ginseng on gastric ulcer models in mice

Background

Korean red ginseng (KRG) is a ginseng that has been cultivated and aged for 4-6 years or more, and goes through an extensive cleaning, steaming and drying process. KRG contains more than 30 kinds of saponin components and has been reported as having various biological properties, such as anti-fatigue action, immune restoration, and neurovegetative effect. The purpose of this study was to assess the effects of a KRG-containing drug (KRGCD) on gastric ulcer models in mice.

Methods

Stomach ulcers were induced by oral ingestion of hydrochloride (HCl)/ethanol or indomethacin. Treatment with KRGCD (30, 100, and 300 mg/kg, p.o.) occurred 1 hr before the ulcer induction. Effect of KRGCD on anti-oxidant activity and gastric mucosal blood flow with a laser Doppler flowmeter in mice stomach tissue was evaluated.

Results

KRGCD (100 and 300 mg/kg, p.o.) significantly decreased ethanol- and indomethacin-induced gastric ulcer compared with the vehicle-treated (control) group. KRGCD (100 and 300 mg/kg) also decreased the level of thiobarbituric acid reactive substance (TBARS) and increased gastric mucosal blood flow compared with the control group.

Conclusions

These results suggest that the gastroprotective effects of KRGCD on mice ulcer models can be attributed to its ameliorating effect on oxidative damage and improving effect of gastric mucosal blood flow.

Water extract of Korean red ginseng stimulates angiogenesis by activating the PI3K/Akt-dependent ERK1/2 and eNOS pathways in human umbilical vein endothelial cells

Angiogenesis is important for promoting cardiovascular disease, wound healing, and tissue regeneration. We investigated the effects of Korean red ginseng water extract (KRGE) on angiogenesis and its underlying signal mechanism. KRGE increased in vitro proliferation, migration, and tube formation of human umbilical vein endothelial cells, as well as stimulated in vivo angiogenesis without increasing VEGF expression. KRGE-induced angiogenesis was accompanied by phosphorylation of ERK1/2, phosphatidylinositol 3-kinase (Akt), and endothelial nitric oxide synthase (eNOS) as well as an increase in NO production. Inhibition of PI3K activity by wortmannin completely inhibited KRGE-induced angiogenesis and phosphorylation of Akt, ERK1/2, and eNOS, indicating that PI3K/Akt activation is an upstream event of the KRGE-mediated angiogenic pathway. The MEK inhibitor PD98059 blocked KRGE-induced ERK1/2 phosphorylation without affecting Akt and eNOS activation. However, the eNOS inhibitor N(G)-monomethyl-L-arginine effectively inhibited tube formation, but partially blocked proliferation and migration as well as ERK phosphorylation, without altering Akt and eNOS activation, revealing that the eNOS/NO pathway is partially involved in ERK1/2 activation. This study demonstrated that KRGE stimulates in vitro and in vivo angiogenesis through the activation of the PI3K/Akt-dependent ERK1/2 and eNOS signal pathways and their cross talk.

Protective role ofPanax ginseng extract standardized with ginsenoside Rg3 against acrylamide-induced neurotoxicity in rats

Acrylamide (ACR) is an industrial neurotoxic chemical that has been recently found in carbohydrate-rich foods cooked at high temperatures. ACR was designated as a probable human carcinogen by IARC (1994) and USEPA (1988). Panax ginseng extract has efficacies such as anticancer, antihypertension, antidiabetes and antinociception. The objective of the current study is to evaluate the protective effects of Panax ginseng extract against ACR-induced toxicity in rats. Sixty adult Sprague Dawley female rats were divided into six groups included a control group, a group treated orally with ACR (50 mg kg(-1) body weight; b.w.) for 11 days, a group treated orally with Panax ginseng extract (20 mg kg(-1) b.w.) for 11 days and groups treated orally with Panax ginseng for 11 days before, during or after 11 days of ACR treatment. The results indicated that treatment with ACR alone resulted in a significant increase in lipid peroxidation level and LDH activity in brain homogenate as well as in serum CK activity, whereas it caused a significant decrease in SOD activity and a small but statistically insignificant decrease in Na(+)K(+)-ATPase activity in brain homogenate. Serum serotonin, corticosterone, T3, T4, TSH, estradiol, progesterone and plasma adrenaline were significantly decreased in ACR-treated rats. Treatment with Panax ginseng before, during or after ACR treatment reduced or partially antagonized the effects induced by ACR towards the normal values of controls. It could be concluded that Panax ginseng extract exhibited a protective action against ACR toxicity and it is worth noting that treatment with Panax ginseng extract before or at the same time as ACR treatment was more effective than when administered after ACR treatment.

Three new furostanol saponins from the leaves of Lycianthes synanthera ("Chomte"), an edible Mesoamerican plant

Three new furostanol oligoglycosides, 3-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranosyl}-26-O-beta-D-glucopyranosyl-22alpha-methoxy-25R-furost-5-ene-3beta,17alpha,26-triol (1), 3-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranosyl}-26-O-beta-D-glucopyranosylfurost-5-ene-3beta,17alpha,22alpha,25,26-pentol (2), and 3-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranosyl}-26-O-beta-D-glucopyranosylfurost-5-ene-3beta,22alpha,25,26-tetrol (3), named lycianthosides A-C, together with known flavone glycosides were isolated from Lycianthes synanthera leaves, an edible plant of the Solanaceae family that grows naturally in Guatemala. The nutrient composition of the raw leaves was also evaluated.

The effect of Korean red ginseng on liver regeneration after 70% hepatectomy in rats

The effect of Korean red ginseng (KRG) on morphologic change and function of the liver was investigated after 70% hepatectomy in rats. The liver weight and hepatocyte proliferation of the KRG treated groups significantly increased compared to those of the control group. KRG inhibited the increase of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, and the number and area of lipid droplets. On the basis of these results, it could be concluded that KRG accelerated the liver regeneration and ameliorated liver injury after hepatectomy in rats.

Simultaneous Determination of Triterpene Saponins in Ginseng Drugs by High-Performance Liquid Chromatography

A HPLC method for the simultaneous determination of 11 triterpene saponins with four-type aglycones (protopanaxadiol, protopanaxatriol, ocotillol and oleanolic acid types) in Ginseng drugs was developed and validated. Using a gradient of acetonitrile and 10 mM K-phosphate buffer (pH 5.80) as the mobile phase and UV detection at 196 nm, more than 18 ginsenosides with different aglycones were separated satisfactorily within 60 min. The detection limits (signal/noise> or =3) were 0.1 microg for ginsenosides Rb1, Rc, Rd, Re and Rg1, chikusetsusaponin III, and notoginsenoside R2, 0.2 microg for gisenoside Ro and chikusetsusaponin IVa, 0.3 microg for chikusetsusaponin IV, and 3 microg for majonoside R2. The calibration curve of each saponin had a correlation coefficient close to 1. Intra- and interday precisions were less than 2.1% (n=5) and 3.3% (n=15), respectively. The recovery rates of extraction were in the range of 96.4-102.7% for all ginsenosides. By adopting this method, the determinations of 11 ginsenosides in three Ginseng drugs derived from Panax ginseng, Panax vietnamensis var. fuscidiscus and Panax japonicus (Japan) were achieved.

The biological action of saponins in animal systems: a review

Saponins are steroid or triterpenoid glycosides, common in a large number of plants and plant products that are important in human and animal nutrition. Several biological effects have been ascribed to saponins. Extensive research has been carried out into the membrane-permeabilising, immunostimulant, hypocholesterolaemic and anticarcinogenic properties of saponins and they have also been found to significantly affect growth, feed intake and reproduction in animals. These structurally diverse compounds have also been observed to kill protozoans and molluscs, to be antioxidants, to impair the digestion of protein and the uptake of vitamins and minerals in the gut, to cause hypoglycaemia, and to act as antifungal and antiviral agents. These compounds can thus affect animals in a host of different ways both positive and negative.

Cancer chemopreventive activity of phenylpropanoid esters of sucrose, vanicoside B and lapathoside A, from Polygonum lapathifolium

To search for cancer chemopreventive agents from natural resources, many phytochemicals have been screened using the in vitro synergistic assay indicated by the inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA). Two phenylpropanoid esters of sucrose, vanicoside B and lapathoside A, were isolated from the aerial part of Polygonum lapathifolium as inhibitors on the EBV-EA induction. These compounds also exhibited significant anti-tumor-promoting effects on mouse two-stage skin carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA, as an initiator) and TPA as a promoter. Further, vanicoside B exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors initiated with an NO donor, NOR-1.

Triterpene saponins from Vietnamese ginseng (Panax vietnamensis) and their hepatocytoprotective activity

The methanol extract of Vietnamese ginseng (Panax vietnamensis) was found to possess hepatocytoprotective effects on D-galactosamine (D-GalN)/tumor necrosis factor-alpha (TNF-alpha)-induced cell death in primary cultured mouse hepatocytes. Further chemical investigation of the extract afforded two new dammarane-type triterpene saponins, ginsenoside Rh(5) (1) and vina-ginsenoside R(25) (2), as well as eight known dammarane-type triterpene saponins, majonoside R(2) (3), pseudo-ginsenoside RT(4) (4), vina-ginsenosides R(1) (5), R(2) (6), and R(10) (7), ginsenosides Rg(1) (8), Rh(1) (9), and Rh(4) (10), and a known sapogenin protopanaxatriol oxide II (11). Their structures were elucidated on the basis of spectral analysis. In addition, by the using LC-electrospray ionization (ESI)-MS method, five known saponins, ginsenosides Rb(1), Rb(2), Rc, Rd, and Re (12--16), were also identified in the extract. Among the compounds isolated, majonoside R(2) (3), the main saponin in Vietnamese ginseng, showed strong protective activity against D-GalN/TNF-alpha-induced cell death in primary cultured mouse hepatocytes. This demonstrates that the hepatocytoprotective effect of Vietnamese ginseng is due to dammarane-type triterpene saponins that have an ocotillol-type side chain, a characteristic constituent of Vietnamese ginseng.

The bioactivity of saponins: triterpenoid and steroidal glycosides

Triterpenoid and steroidal glycosides, referred to collectively as saponins, are bioactive compounds present naturally in many plants. They have considerable potential as pharmaceutical and/or nutraceutical agents in natural or synthetic form. Saponins, from a variety of sources, have been shown to have hypocholesterolemic, anti-coagulant, anticarcinogenic, hepatoprotective, hypoglycemic, immunomodulatory, neuroprotective, anti-inflammatory and anti-oxidant activity. This paper reviews saponin research of the last decade, focussing on developments in understanding their mechanism of action and structure-activity relationships. Virtually all of this work has used animal and in vitro models. To date there are very few human data.

Dietary strategies to counteract the effects of mycotoxins: a review

We reviewed various dietary strategies to contain the toxic effects of mycotoxins using antioxidant compounds (selenium, vitamins, provitamins), food components (phenolic compounds, coumarin, chlorophyll and its derivatives, fructose, aspartame), medicinal herbs and plant extracts, and mineral and biological binding agents (hydrated sodium calcium aluminosilicate, bentonites, zeolites, activated carbons, bacteria, and yeast). Available data are primarily from in vitro studies and mainly focus on aflatoxin B1, whereas much less information is available about other mycotoxins. Compounds with antioxidant properties are potentially very efficacious because of their ability to act as superoxide anion scavengers. Interesting results have been obtained by food components contained in coffee, strawberries, tea, pepper, grapes, turmeric, Fava tonka, garlic, cabbage, and onions. Additionally, some medicinal herbs and plant extracts could potentially provide protection against aflatoxin B1 and fumonisin B1. Activated carbons, hydrated sodium calcium aluminosilicate, and bacteria seem to effectively act as binders. We conclude that dietary strategies are the most promising approach to the problem, considering their limited or nil interference in the food production process. Nevertheless, a great research effort is necessary to verify the in vivo detoxification ability of the purposed agents, their mode of action, possible long-term drawbacks of these detoxification-decontamination procedures, and their economical and technical feasibility.

Anti-tumor-promoting activity of lignans from the aerial part of Saussurea medusa

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Compositae plants were screened. Consequently, the lignans, arctiin (ARC) and arctigenin (ARC-G), were obtained from the aerial part of Saussurea medusaas active constituents. These compounds exhibited the remarkable anti-tumor-promoting effect on two-stage carcinogenesis test of mouse skin tumors induced by 7, 12-dimethylbenz[a]anthracene as an initiator and 12-O-tetradecanoyl phorbol-13-acetate as a promoter by both topical application and oral administration. Furthermore, ARC-G exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse pulmonary tumors induced by 4-nitroquinoline-N-oxide as an initiator and glycerol as a promoter.

Inhibition by ginseng of 1,2-dimethylhydrazine induction of aberrant crypt foci in the rat colon

The modifying effects of dietary administration of ginseng on the induction and development of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) were investigated in Fischer 344 (F-344) rats. In Experiment 1, starting at six weeks of age, 65 rats were injected with DMH or saline alone once a week for four weeks. Rats in Groups 1 and 2 were fed diets containing 1% ginseng for five weeks, starting one week before the first dose of DMH. Animals in Groups 3 and 4 received ginseng for eight weeks after DMH treatment; Group 5 served as a carcinogen control group. In Experiment 2, 60 rats were injected with DMH or saline alone four times at one-week intervals. They were also fed diets containing 1% ginseng or the control diet throughout the 30 days of the experiment. In Experiment 1, numbers of foci with at least four crypts were significantly reduced in Group 2 treated with red ginseng during the initiation phase (p < 0.005). In Experiment 2, treatment with red ginseng also resulted in a decrease in the total number of DMH-induced ACF accompanied by a reduction in 5-bromo-2'-deoxyuridine labeling indexes in colonic crypts comprising ACF (p < 0.005 and p < 0.05, respectively). These findings suggest that dietary administration of red ginseng in combination with DMH suppresses colon carcinogenesis of rats, and the inhibition may be associated, in part, with suppression of cell proliferation in the colonic mucosa.

Cancer chemopreventive activity of euglobal-G1 from leaves of Eucalyptus grandis

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Eucalyptus plants were screened. Consequently, the phlorogrucinol-monoterpene derivative, euglobal-G1 (EG-1), was obtained from the leaves of Eucalyptus grandis as an active constituent. EG-1 exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors induced by 7, 12-dimethylbenz[a]anthracene (DMBA) as an initiator and fumonisin-B1, which has been known as one of mycotoxins produced by Fusarium monifliforme, as a promoter. Further, EG-1 exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse pulmonary tumor using 4-nitroquinoline-N-oxide (4-NQO) as an initiator and glycerol as a promoter.

Potential antitumor-promoting diterpenoids from the stem bark of Picea glehni

A novel rearranged labdane-type diterpenoid, 19(4-->3)abeo-8alpha, 13(S)-epoxylabda-4(18),14-diene (1), and two new abietane-type diterpenoids, 19-nor-abieta-4(18),8,11,13-tetraen-7-one (2) and 12-hydroxydehydroabietic acid (3) were isolated from the stem bark of Picea glehni, together with seven known diterpenoids-13-epimanoyl oxide (4), dehydroabietic acid (5), (11E)-14, 15-bisnor-8alpha-hydroxy-11-labden-13-one (6), abieta-8,11, 13-trien-7-one (7), 9alpha,13alpha-epidioxyabiet-8(14)-en-18-oic acid (8), 9,10alpha-epoxy-9,10-seco-abieta-8,11,13-trien-18-oic acid (9), and methyl 15-hydroxy-7-oxo-dehydroabietate (10). Compounds 5-8 and 10 showed potent inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate.

Bioactive saponins in vietnamese ginseng, panax vietnamensis

Vietnamese ginseng, Panax vietnamensis was recently found in central Vietnam, and regarded as a new botanical species. It was used in traditional folk medicine in hill tribes for the purpose of anti-fatigue and life saving. From the rhizome and root of this plant, 37 saponins including 14 new compounds were isolated. Some of them were common to other Panax spp., but the general yields in this species were very high. Among them, an ocotillol-type saponin majonoside-R2 (MR2) was remarkable in its yield (5.3%). Structural features of new saponins were briefly introduced. The biological effects of these saponins were studied in two ways, anti-stress effect and anti-tumor promoting effect; both activities were based upon the traditional usage of this crude drug. In psychologically stressed mice, the saponin fraction of Vietnamese ginseng significantly reduced stress-related disorders (reducing sleeping time, formation of gastric lesions) and MR2 was responsible for this effect. A possible mechanism for this effect was proposed. MR2 exhibited a significant inhibitory effect on Epstein-Barr virus early antigen (EBV-EA) induced by the tumor promoter phorbol acetate. MR2 also showed potent anti-tumor-promoting activity on mouse skin and hepatic tumors.

Bioactive steroids from the whole herb of Euphorbia chamaesyce

Three new ergostane-type steroids, 3beta-hydroxy-4alpha, 14alpha-dimethyl-5alpha-ergosta-8,24(28)-dien-11 -one (1); 3beta, 11alpha-dihydroxy-4alpha,14alpha-dimethyl-5alpha -ergosta-8, 24(28)-dien-7-one (2); and 3beta,7alpha-dihydroxy-4alpha, 14alpha-dimethyl-5alpha-ergosta-8,24(28)-dien-11 -one (3), were isolated, together with two known triterpenoids, wrightial and lup-20(30)-ene-3beta,29-diol from the whole herb of Euphorbia chamaesyce. Compound 3 showed a potent inhibitory effect on Epstein-Barr virus early antigen activation induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA).

Cancer chemopreventive activity of majonoside-R2 from Vietnamese ginseng, Panax vietnamensis

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Panax plants were screened. Consequently, the ocotillol-type saponin, majonoside-R2 (MR2), was obtained from the rhizome and root of Panax vietnamensis (Vietnamese ginseng) as an active constituent. MR2 exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse hepatic tumor using N-nitrosodiethylamine (DEN) as an initiator and phenobarbital (PB) as a promoter. Further, MR2 exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin induced by nitric oxide (NO) donor/12-O-tetradecanoylphorbol-13-acetate (TPA) or peroxynitrite/TPA.

Cancer chemopreventive agents (antitumor-promoters) from Ajuga decumbens

Sixteen compounds (1-16) isolated from the flowering whole plant of Ajuga decumbens have been tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) induction by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), as a primary screening test for antitumor-promoters (potential cancer chemopreventive agents). Five compounds (6, 9, and 12-14) showed strong inhibitory effects on EBV-EA induction. Of these active compounds, two major constituents of this plant, cyasterone (6) and 8-acetylharpagide (13), showed potent antitumor-promoting activities on a mouse-skin in vivo two-stage carcinogenesis procedure, using 7, 12-dimethylbenz[a]anthracene as initiator and TPA as promoter. Further, compound 13 also exhibited potent chemopreventive activity in a mouse pulmonary tumor model.