Decreased Hill reaction rates and slow turnover of transitory starch in the obligate shade plant Panax quinquefolius L. (American ginseng)

To identify physiological processes that might limit photosynthesis in Panax quinquefolius L. (American ginseng) a comparison has been made with Panax ginseng C.A. Meyer (Korean ginseng), Pisum sativum L. (pea) and Spinacia oleracea L. (spinach). The quantum yield of oxygen evolution in intact leaves and isolated thylakoid membranes was found to be smaller in ginseng than in pea or spinach. However, the number of photosystem II (PSII) centers on a chlorophyll basis was found to be similar in all species. This suggests that ginseng thylakoid membranes possess relatively more inactive PSII centers than thylakoids of pea and spinach when grown under similar conditions. Unexpectedly, whole-chain electron transport from water to methyl viologen, and partial photosystem I reactions, demonstrated that electron transport rates to methyl viologen were anomalously low in P. quinquefolius and P. ginseng. Additionally, at elevated light intensities, intact leaves of P. quinquefolius were more susceptible to lipid peroxidation than pea leaves. In plants grown at a light intensity of 80 micro mol photons m(-2) s(-1) the levels of fructose and starch were higher in both ginseng species than in pea or spinach. Significantly, the level of starch in P. quinquefolius was relatively constant throughout the entire 12 h/12 h light/dark cycle and remained high after an extended dark time of 48 h. In addition, P. quinquefolius had lower activities of alpha-amylase and beta-amylase than P. ginseng, pea and Arabidopsis thaliana (L.) Heynh. The significance of the elevated levels of leaf starch in P. quinquefolius remains to be determined. However, the susceptibility of P. quinquefolius to photoinhibition may arise as a consequence of a reduced fraction of active PSII centers. This may result in the normal dissipative mechanisms in these plants becoming saturated at elevated, but moderate, light intensities.     

Extractable polysaccharides of Panax quinquefolius L. (North American ginseng) root stimulate TNFalpha production by alveolar macrophages.

We have investigated the immunostimulatory activity of the medicinal plant Panax quinquefolius L. (North American ginseng). Rat alveolar macrophages were treated with different extracts from 4-year old roots, and tumour necrosis factor alpha (TNF) production was used as a measure of immunostimulatory activity. Aqueous extracts of P. quinquefolius root (1-100 microg/ml) were found to significantly stimulate alveolar macrophage TNF release. Both a P. quinquefolius methanol extract containing ginsenosides (but no polysaccharides), and pure ginsenoside-Rb1, the major ginsenoside present in P. quinquefolius, were found to be inactive as TNF-stimulating agents. Significant TNF-stimulating activity was found in the extractable polysaccharide fraction, which was hydrolyzed and found to contain glucose, galactose, arabinose, rhamnose, and mannose. This represents the first evidence that North American ginseng exerts cytokine-stimulating activity on macrophages.     

Mycotoxins in root extracts of American and Asian ginseng bind estrogen receptors alpha and beta

The estrogenic activity of ginseng has been the subject of conflicting reports. Cell proliferation, induction of estrogen-responsive genes, and isolated cases of adverse reactions such as postmenopausal vaginal bleeding and gynecomastia have been reported after ginseng treatment. Other studies report antiproliferative effects with no induction of estrogen-responsive genes. We developed estrogen receptor (ER) alpha and ER alpha competitive binding assays using recombinant receptors and [(3)H]-17 alpha-estradiol to detect phytoestrogens in extracts of Asian ginseng root (Panax ginseng C. A. Meyer) and American ginseng root (Panax quinquefolius L.). Root extracts contained substances that bound both receptor isoforms. These substances had a two to three times greater affinity for ER alpha. Significantly higher binding was found in methanol extracts than in hot water extracts. Subsequent analysis of the extracts revealed significant ER binding attributable to zearalenone, the estrogenic mycotoxin produced by several Fusarium species. The ER showed no binding affinity for Rb1 and Rg1, the major ginsenosides found in P. quinquefolius and P. ginseng, respectively. Thus, ginseng extraction methods, plant species tested, and mycotoxin contaminants may help to explain the disparate literature reports. The prevalence and health significance of fungal contamination in herbal products used for medicinal purposes should be further investigated.     

Isolation and characterization of repetitive DNA sequences from Panax ginseng

Repetitive sequences constitute a significant component of most eukaryotic genomes, and the isolation and characterization of repetitive DNA sequences provide an insight into the organization and evolution of the genome of interest. We report the isolation and characterization of the major classes of repetitive sequences from the genome of Panax ginseng. The isolation of repetitive DNA from P. ginseng was achieved by the reannealing of chemically hydrolyzed (200 bp-1 kb fragments) and heat-denatured genomic DNA to low C(o)t value. The low C(o)t fraction was cloned, and fifty-five P. ginseng clones were identified that contained repetitive sequences. Sequence analysis revealed that the fraction includes repetitive telomeric sequences, species-specific satellite sequences, chloroplast DNA fragments and sequences that are homologous to retrotransposons. Two of the retrotransposon-like sequences are homologous to Ty1/ copia-type retroelements of Zea mays, and six cloned sequences are homologous to various regions of the del retrotransposon of Lilium henryi. The del retrotransposon-like sequences and several novel repetitive DNA sequences from P. ginseng were used to differentiate P. ginseng from P. quinquefolius, and should be useful for evolutionary studies of these disjunct species.     

Identification of new microsatellite markers in Panax ginseng

Microsatellites, also called simple sequence repeats (SSR), are very useful molecular genetic markers commonly used in crop breeding, species identification and linkage analysis. In the present study, we constructed a microsatellite-enriched genomic library of Panax ginseng, and identified 251 novel microsatellite sequences. Tri-nt repeat units were the most abundant (46.6%), followed by di-nt repeats (35.5%). The (AG)n motif was most common (23.1%), followed by the (AAC)n motif (22.3%). From the genotyping of 94 microsatellites using marker-specific primer sets, we identified 11 intraspecific polymorphic markers as well as 14 possible interspecific polymorphic markers differing between P. ginseng and P. quinquefolius. The exact allele structures of the polymorphic markers were determined and the alleles were named. This study represents the first report of the bulk isolation of microsatellites by screening a microsatellite-enriched genomic library in P. ginseng. The microsatellite markers could be useful for linkage analysis, genetic breeding and authentication of Panax species.     

三七叶、人参叶和西洋参叶皂苷类成分的研究(英文)

三七叶、人参叶和西洋参叶其皂苷类成分相近,但专属性成分各异,皂苷类成分的分布比例也各不相同。本文建立了HPLC-UV法测定上述皂苷成分的方法,经过方法学考察,各种皂苷成分精密度好、加样回收率高,方法可靠。11种皂苷成分总含量顺序为:西洋参叶>人参叶>三七叶;二醇组皂苷成分含量:西洋参叶>三七叶>人参叶;三醇组皂苷成分含量:人参叶>西洋参叶>三七叶。西洋参叶中二醇组皂苷和人参叶中三醇组皂苷含量明显高于其他。西洋参叶中人参皂苷Rb3和Rd的含量之和占11种皂苷成分的60%以上。鉴于其中人参皂苷的高含量,三七叶、人参叶和西洋参叶应该作为皂苷来源得到充分利用;不同的皂苷成分有不同的药理活性,应基于它们的皂苷组成和比例选择性进行研究和开发。     

Pollen ultrastructure of Panax(the ginseng genus, Araliaceae),an eastern Asian and eastern NorthAmerican disjunct genus

Pollen of ten species of Panax and six species of Aralia was examined in light microscopy and scanning and transmission electron microscopy. Grains of both genera have similar complex apertures, short columellae, and overlapping tectal sculptures, suggesting a close relationship. Most species of Panax have pollen characterized by striato-reticulate tecta, short columellae, thick foot layers, costa ectocolpi, and lalongate endoapertures. The eastern North American P. trifolius, commonly known as the dwarf ginseng, has a distinctive pollen morphology and exine structure, supporting the hypothesis of its phylogenetically isolated position. Pollen of the eastern Asian P. ginseng (ginseng) can be distinguished from the eastern North American P. quinquefolius (American ginseng) by differences in ultrastructure. The monophyly of the three medicinally important species, P. ginseng, P. notoginseng, and P. quinquefolius, suggested by triterpenoid data, is not supported by pollen data. The results of the pollen study are generally congruent with those from the sequences of nuclear ribosomal DNA.     

The cyto-taxonomic studies on some species of Panax L.

Abstract 1. It was observed that somatic chromosome numbers of four species of the genus Panax L. are as follows: Panax japonicus 2n=24, P. notoginseng 2n=24, P. ginseng 2n=44 and P. quinquefolius 2n=48. The somatic chromosome numbers of P. japonicus from Lushan and Jinggangshan (Jiangxi Province, China) is different from that of Japanese population (2n=48). The chromosome numbers (2n=24) of P. notoginseng is first reported. 2. The P. japonicus, one of the diploid species, which has the widest geographical distribution is perhaps the more primitive type among the living species of Panax. While, the P. ginseng and P. quinquefolius, the tetraploid species, are more advanced types than the diploid species. The conclusion from cytotaxonomy is thus different from that of chemical taxonomy. 3. The cytological analysis together with the geographic distribution of this four species shows that the Southwestern China is the modern distribution center, also the most variational center, and perhaps the center of origin for the genus Panax L.     

Effects of Panax quinquefolius L. on brainstem neuronal activities: comparison between Wisconsin-cultivated and Illinois-cultivated roots.

Brainstem neurons receiving subdiaphragmatic vagal inputs were recorded in an in vitro neonatal rat brainstem-gastric preparation. Aqueous extracts of American ginseng root (Panax quinquefolius L.) from Wisconsin and Illinois were applied to the gastric compartment or the brainstem compartment of the bath chamber to evaluate the peripheral gut or central brain effects of the extracts on brainstem unitary activity. After P. quinquefolius extract application to the gastric or brainstem compartment, a concentration-related inhibition in neuronal discharge frequency in brainstem unitary activity was observed, suggesting that P. quinquefolius plays an important role in regulating the digestive process and modulating the brain function in the rat. In this study, pharmacological effects of Wisconsin-cultivated P. quinquefolius and Illinois-cultivated P. quinquefolius were compared. Our results showed that Illinois-cultivated P. quinquefolius possesses a significantly stronger peripheral gastric as well as central brain modulating effect on brainstem neuronal activity. Data from our high performance liquid chromatography ginsenoside analysis suggest that this increase in inhibitory effects by Illinois-cultivated P. quinquefolius may be due to its different ginsenoside profile.     

人参毛状根生物合成熊果苷的分离与鉴定

熊果苷(arbutin),化学名称为对-羟基苯-β-D-吡喃葡萄糖苷,能够竞争性抑制酪氨酸酶的活性从而抑制黑色素的形成,被国际公认为高效祛斑美白剂,是化妆品中理想的添加成分.人参(Panax ginseng C. A. Mey.)自古以来就是名贵药材,由于人参在栽培过程中存在着栽培困难、周期过长、地域限制等难题,人参的组织培养受到了广泛的重视.本实验室已建立了人参细胞大量培养体系[1]和人参毛状根培养体系[2],并把熊果苷与人参细胞配伍应用到化妆品生产中,产品深受广大消费者青睐.用植物培养物对外源底物进行生物转化,从而对其结构进行修饰,以获得更有意义的产物的研究报道很多[3～9],也是当今研究的热点.本实验室已对人参生物转化熊果苷的基本条件进行了初步探讨[10],本文在此基础上,对转化产物进行了分离鉴定.     

Identification and differentiation of Panax species using ELISA, RAPD and eastern blotting

Immunochemical and genetic methods have been developed in order to distinguish Panax spp. With the aim of establishing immunochemical methods, two hybridomas (3H4 and 5H8), each secreting a monoclonal antibody (MAb) against proteins of Panax ginseng, were prepared by fusing splenocytes immunized with two kinds of ginseng water-soluble fractions and a hypoxanthine-thymidine-aminopterin-sensitive mouse myeloma cell line, P3-X63-Ag8-U1. MAb 3H4 cross-reacted with four Panax spp., whereas the MAb 5H8 cross-reacted with P. ginseng in the enzyme-linked immunosorbent assay (ELISA). ELISA and western blotting methods using a ginseng water-soluble fraction as the solid-phase antigen were developed for the unambiguous authentication of P. ginseng. A combination of random amplified polymorphic DNA (RAPD) and eastern blotting analyses using anti-ginsenoside Rb1 and Rgl monoclonal antibodies was used for the identification of P. notoginseng, P. quinquefolius and P. japonicus. RAPD can be used to differentiate the species of Panax from each other. An important parameter used for differentiating P. notoginseng is the absence of ginsenoside Rc in the extract of P. notoginseng with eastern blotting. The combination of these methods enabled a reliable identification of Panax spp.     

Effect of adaptogens on the activity of the pituitary-adrenocortical system in rats

Intraperitoneal injection of Panax ginseng C. A. Mey tincture, Polyscias filicifolia Bailey tincture, Panax ginseng tincture or Eleutherococcus Maxim extract to rats produced a rise in plasma corticosterone 1 hour after the treatment. Immobilization-induced rise in plasma corticosterone was increased by 7-day pretreatment with any agent. Thus, the adaptation effect of Panax ginseng C. A. Mey and Polyscias filicifolia Bailey is probably realized through the pituitary-adrenocortical system.     

RAPD- and allozyme analysis of genetic variability of Panax ginseng C.A. Meyer and P. quinquefolius L

Inter- and intraspecific variation of two ginseng species Panax ginseng and P. quinquefolius was estimated by studying 159 RAPD and 39 allozyme loci. Parameters of polymorphism and genetic diversity were determined and a tree was constructed to characterize the differences between individual plants, samples, and species. Genetic variation in P. ginseng proved to be lower than in P. quinquefolius. Gene diversity in the total P. ginseng sample was comparable with the mean expected heterozygosity of herbaceous plants. This suggests that wild P. ginseng plants in various areas of the currently fragmented natural habitat and cultivated plants of different origin have retained a significant proportion of their gene pool. The mean heterozygosity calculated per polymorphic locus for the RAPD phenotypes is similar to that of the allozyme loci and may be helpful in estimating gene diversity in populations of rare and endangered plant species.     

Proteome of Oriental ginseng Panax ginseng C. A. Meyer and the potential to use it as an identification tool

Oriental ginseng (Panax ginseng C. A. Meyer) and American ginseng (Panax quinquefolius) are two widely used valuable traditional Chinese medicines (TCM). Previously, the identification of ginseng was mainly performed by analyzing the ginsengnosides using high performance liquid chromatography and amplification of polymorphic DNA using polymerase chain reaction. However, these methods cannot be used to distinguish TCM samples which are from different parts (main root, lateral roots, rhizome head and skin) of ginseng and ginseng culture cells from wild-grown ginseng. The present study aimed to identify different species of ginseng, different parts of the same ginseng and cultured cells of ginseng using a proteomic approach. Two-dimensional electrophoresis (2-DE) maps were established from the American ginseng main root, different parts (main root, lateral roots, rhizome head and skins) of Oriental ginseng and Oriental ginseng culture cells. Our results show that the 2-DE maps of different ginseng samples contain sufficient differences to permit easy discrimination. We have also identified common and specific protein spots in the 2-DE maps of different ginseng samples. The use of these "marker proteins" may help to speed up the identification process.     

Genetic identification of Panax ginseng and Panax quinquefolius by pyrosequencing methods

This study was performed to determine whether two ginseng species (Panax ginseng and Panax quinquefolius) can be identified by genetic analysis and to verify pyrosequencing analysis, which was used to assess genetic variation. The pyrosequencing results constituted clear data. Panax quinquefolius showed a very different pattern than Panax ginseng. Pyrosequencing analysis might be able to identify the Panax species.     

西洋参和人参的可溶蛋白电泳鉴别

西洋参 (ＰａｎａｘｑｕｉｎｑｕｅｌｉｕｍＬ .)又称花旗参、美国人参 ,原产美国和加拿大 ,在我国的保健品市场占有很大的销售份额 ,西洋参在我国虽已引种成功 ,但主要还靠国外进口 ,价格昂贵 ,因此很多保健品利用价格相对低廉的人参 (Ｐ .ｇｉｎｇｓｅｎｇＣ .Ａ .Ｍｅｙ)伪充西洋参。近年来国内有许多学者利用多种手段对西洋参和人参进行鉴别 ,但由于西洋参和人参的性状、成分极其相似 ,现有的方法难以将二者完全区分开来 ,因此 ,有必要寻求新的快速灵敏的鉴别方法。蛋白质电泳方法早已广泛应用于医学、农学和微生物学 ,目前也逐步运用于…     

Spatial and genetic structure within populations of wild American ginseng (Panax quinquefolius L., Araliaceae)

Spatial structure and fine-scale genetic structure were analyzed for the medicinal plant American ginseng (Panax quinquefolius L.) to more fully understand biological processes within wild populations. P. quinquefolius has been harvested for more than 250 years and is now considered threatened or rare throughout its range. Plants within four protected and four unprotected populations were significantly clumped based on Ripley's univariate analysis. Analysis with Ripley's bivariate test determined that juvenile plants were significantly clumped with adult plants at the shortest distance classes in all populations. Although plants were highly clumped, we found that significant fine-scale genetic structure was restricted to the shortest distance classes based on estimates of coancestry (f(ij)). In most cases, estimates of f(ij) were more significant among juveniles than among adults, especially at the shortest distance classes. The spatial structure of ginseng seems to result from the establishment and persistence of plants in favorable microhabitats coupled with limited seed dispersal around maternal individuals. There were no differences in patterns of fine-scale genetic structure between protected and unprotected populations.     

Genetic diversity in harvested and protected populations of wild American ginseng, Panax quinquefolius L. (Araliaceae)

Genetic diversity was examined at 16 allozyme loci in 21 wild populations of the medicinal plant American ginseng, Panax quinquefolius L. (Araliaceae). This species has been harvested from forests in North America for more than 250 years. Average expected heterozygosity was significantly greater within protected populations (H(e) = 0.076) than within populations in which harvesting was permitted (H(e) = 0.070). More notably, genetic structure was greater among unprotected populations (G(ST) = 0.491) than among protected populations (G(ST) = 0.167). These differences in the level and distribution of genetic diversity in American ginseng populations indicate that harvesting may have significant evolutionary implications for this species. Age class structure also shifted toward smaller, nonreproductive plants in unprotected populations. Juvenile plants had lower genetic diversity (H(e) = 0.067) than reproductive plants (H(e) = 0.076) suggesting that conserving a proportion of the largest (oldest) plants in each population is important to protect reproductive fitness and the evolutionary potential of the species. Due to its high genetic structure, conservation recommendations include protecting populations throughout the range of P. quinquefolius.     

Rhexocercosporidium panacis sp. nov., a new anamorphic species causing rusted root of ginseng (Panax [corrected] quinquefolius)

A new species of the anamorphic genus Rhexocercosporidium is described. Isolates of a Rhex-Rhexocercosporidium sp. were obtained from ginseng (Panax quinquefolius) roots with symptoms of rusted root. These isolates were found to be genetically and morphologically distinct from the only described species in this genus, R. carotae. Sequence data from the ribosomal DNA region spanning the internal transcribed spacers 1 and 2 and from a portion of the 3-tubulin gene of the ginseng Rhexocercosporidium were compared to those of R. carotae. Parsimony analyses of sequence data showed that R. carotae and the ginseng isolates belonged to distinct but closely related clades. Conidia of a typical ginseng isolate were significantly shorter and possessed fewer septa than R. carotae but shared rhexolytic secession of conidia with R. carotae. The binomial Rhexocercosporidium panacis is proposed to accommodate isolates of this genus that are associated with the rusted root disease.     

Effect of growth regulators on ginsenoside production in the cell culture of two ginseng species

Plants belonging to the genus Panax produce ginsenosides that possess pharmacological properties. The ability to synthesize these compounds is preserved in some cultured cells of ginseng. In this work, we used suspension cell cultures of two species of ginseng: Panax japonicus var. repens C. A. Mey and P. ginseng C. A. Mey. The first culture was grown on MS medium supplemented with α-NAA. After one subculturing, cell biomass increased 5–6 times with the level of ginsenosides being equal to 2.5–3.0% of dry weight. The second culture was grown on the same medium supplemented with 2,4-D. In this case, biomass increment was 3–5-fold, and ginsenosides were produced in trace amounts. Substitution of 2,4-D for NAA in suspension cell culture of P. japonicus brought about deterioration of growth characteristics, but the content and composition of ginsenosides was not changed. In the suspension cell culture of P. ginseng, substitution of NAA for 2,4-D decreased the rate of biomass accumulation and increased the extent of cell aggregation, with total content of ginsenosides increasing 25 times and their assortment being complete.