Nutrients cause grassland biomass to outpace herbivory.

Human activities are transforming grassland biomass via changing climate, elemental nutrients, and herbivory. Theory predicts that food-limited herbivores will consume any additional biomass stimulated by nutrient inputs ('consumer-controlled'). Alternatively, nutrient supply is predicted to increase biomass where herbivores alter community composition or are limited by factors other than food ('resource-controlled'). Using an experiment replicated in 58 grasslands spanning six continents, we show that nutrient addition and vertebrate herbivore exclusion each caused sustained increases in aboveground live biomass over a decade, but consumer control was weak. However, at sites with high vertebrate grazing intensity or domestic livestock, herbivores consumed the additional fertilization-induced biomass, supporting the consumer-controlled prediction. Herbivores most effectively reduced the additional live biomass at sites with low precipitation or high ambient soil nitrogen. Overall, these experimental results suggest that grassland biomass will outstrip wild herbivore control as human activities increase elemental nutrient supply, with widespread consequences for grazing and fire risk.

Promotion of axonal maturation and prevention of memory loss in mice by extracts of Astragalus mongholicus.

BACKGROUND AND PURPOSE: Neurons with atrophic neurites may remain alive and therefore may have the potential to regenerate even when neuronal death has occurred in some parts of the brain. This study aimed to explore effects of drugs that can facilitate the regeneration of neurites and the reconstruction of synapses even in severely damaged neurons. EXPERIMENTAL APPROACH: We investigated the effects of extracts of Astragalus mongholicus on the cognitive defect in mice caused by injection with the amyloid peptide Abeta(25-35). We also examined the effect of the extract on the regeneration of neurites and the reconstruction of synapses in cultured neurons damaged by Abeta(25-35). KEY RESULTS: A. mongholicus extract (1 g kg(-1) day(-1) for 15 days, p.o.) reversed Abeta(25-35)-induced memory loss and prevented the loss of axons and synapses in the cerebral cortex and hippocampus in mice. Treatment with Abeta(25-35) (10 microM) induced axonal atrophy and synaptic loss in cultured rat cortical neurons. Subsequent treatment with A. mongholicus extract (100 microg/ml) resulted in significant axonal regeneration, reconstruction of neuronal synapses, and prevention of Abeta(25-35)-induced neuronal death. Similar extracts of A. membranaceus had no effect on axonal atrophy, synaptic loss, or neuronal death. The major known components of the extracts (astragalosides I, II, and IV) reduced neurodegeneration, but the activity of the extracts did not correlate with their content of these three astragalosides. CONCLUSION AND IMPLICATIONS: A. mongholicus is an important candidate for the treatment of memory disorders and the main active constituents may not be the known astragalosides.

Effects of hydrocortisone and beta-aminopropionitrile on stress-strain and stress-relaxation behaviors, and birefringent retardation of collagen fibers in the rat incisor periodontal ligament.

Three groups of male Wistar rats received daily subcutaneous injections of 10 mg/kg of hydrocortisone (HC group), 300 mg/kg of beta-aminopropionitrile (BAPN group), or saline (control group), for 10 days. The shear stress-strain and stress-relaxation properties of the incisor periodontal ligament were examined in transverse sections from dissected mandibles. Both the maximum shear stress and failure strain energy density increased significantly following the administration of hydrocortisone. The maximum shear stress decreased following the administration of BAPN. However, the stress-relaxations in the initial 10 min did not show significant differences among the three groups. Polarized light microscopic analysis revealed that the retardation value of the collagen fibers was highest in the HC group and lowest in the BAPN group for the bone-related area, but not for the tooth-related and middle areas of the ligament. It is suggested that the changes induced by hydrocortisone or BAPN occurred mainly in the elastic components and to a minor extent in the viscous components although the physical and biomechanical properties are determined by the interaction of all the various components. We also suggest that the main response to the drugs occurred in the collagen fibers in the bone-related area of the ligament.

Inhibition of itch-scratch response by fruits of Cnidium monnieri in mice.

We previously screened the anti-itching activities of 33 herbal medicines in substance P (SP)-induced itching model mice. One of the most potent antipruritogenic extracts, the methanol extract of fruits of Cnidium monnieri (Cnidii Fructus) was studied further. The chloroform-soluble fraction of the methanol extract markedly inhibited SP-induced scratching. Among 10 subfractions of the chloroform-soluble fraction, the CS-3 fraction had the most potent inhibitory effect on scratching. Each of 3 subfractions of CS-3 showed significant anti-scratching activities. However, inhibitory potencies were not different among the three and weaker than that of CS-3 itself at a same dose. These 3 subfractions of CS-3 mainly contained xanthotoxin, isopimpinellin, bergapten, imperatorin and osthol. Single administration of osthol did not inhibit SP-induced scratching, and imperatorin very weakly subsided scratching. These results suggest that the strong antipruritic action was focused on the CS-3 fraction of the C. monnieri methanol extract, and it might result from the combined effects of these coumarin derivatives, or by undetermined minor compounds.

[Identification of notoginseng(Panax notoginseng) and its adulterants using DNA sequencing].

OBJECTIVE: To analyze the nuclear ribosomal RNA small subunit (18S rRNA) and chloroplast matK gene sequence of notoginseng (Panax notoginseng) in order to provide molecular evidence for its genuine origin identification. METHODS: To sequence 18S rRNA and matK genes of Panax notoginseng and its four adulterants such as P. japonicus, Curcuma phaeocaulis, C. wenyujin, C. kwangsiensis using PCR direct sequencing and to detect their variation of sequences. RESULTS: The sequence length of notoginseng and its adulterants is 1809-1811 bp for 18S rRNA gene and 1259-1548 bp for matK gene, respectively. Multiple sequence alignment shows that there are much sequence variation between notoginseng and its adulterants. CONCLUSION: DNA sequencing is an accurate and reliable method in origin identification of the genuine notoginseng.

Phylogenetic analysis based on 18S rRNA gene and matK gene sequences of Panax vietnamensis and five related species.

Panax vietnamensis was discovered recently in Vietnam. Its bamboo-like rhizomes, called Vietnamese Ginseng, have attracted considerable attention because of their specific pharmacological activities. In order to define the taxonomic position of this new species and include it in the molecular authentication of Ginseng drugs, the 18S ribosomal RNA gene and matK gene sequences of P. vietnamensis were determined and compared with those of its related taxa, P. japonicus var. major and P. pseudo-ginseng subsp. himalaicus, besides previously reported P. ginseng, P. japonicus and P. quinquefolius. The 18S rRNA gene sequences were found to be 1809 bps in length. The sequence of P. vietnamensis was identical to that of P. quinquefolius, and presented one base substitution from those of both P. japonicus var. major and P. pseudo-ginseng subsp. himalaicus. The matK gene sequences of 6 taxa were found to be 1509 bps in length. The sequence of P. vietnamensis differed from those of P. japonicus var. major, P. pseudo-ginseng subsp. himalaicus, P. ginseng, P. japonicus and P. quinquefolius at 4, 5, 9, 9 and 10 nucleotide positions, respectively. The phylogenetic tree reconstructed by the combined 18S rRNA-matK gene analysis using the maximum parsimony method showed that P. vietnamensis was sympatric with other Panax species and had a close relationship with P. japonicus var. major and P. pseudo-ginseng subsp. himalaicus.

Protective effect of Salvia miltiorrhiza on angiotensin II-induced hypertrophic responses in neonatal rat cardiac cells.

The effect of the root of Salvia miltiorrhiza (SM) on angiotensin II (Ang II)-induced hypertrophic responses was examined in cultured neonatal rat cardiac cells (cardiomyocytes and non-cardiomyocytes). The methanol eluate fraction (SM2) of the water extract and the ethyl acetate-insoluble fraction (SM3) and its soluble fraction (SM4) partitioned from the methanol extract were prepared. Treatment with SM4 (5-80 microg/ml), not SM2 and SM3, for 24 h produced dose-dependent cytotoxicity against cardiac cells relative to the reduction in viability and the morphological injury of cardiomyocytes. SM2 or SM3 in the absence of Ang II affected neither hyperplastic nor hypertrophic growth of both cell types. However, SM3 (40 microg/ml) attenuated the positive chronotropic responsiveness of cardiomyocytes to Ang II (1 nM) stimulation, whereas Ang II-induced increase in non-cardiomyocyte number was decreased only by SM2 (40 microg/ml) treatment. Furthermore, SM3 suppressed Ang II-induced enlargement of cell size by preceding Ang II-induced induction of immediate early response gene (c-jun) expression in cardiomyocytes, while SM2 decreased Ang II-induced DNA synthesis in non-cardiomyocytes. Moreover, three phenolic compounds and tanshinone IIA that differed quantitatively among three SM fractions were identified by reverse-phase high performance liquid chromatography. Thus, the present findings indicate that the root of SM is an effective inhibitor of Ang II action and has a plural effective constituent, which possess different pharmacological activities on Ang II-induced hypertrophy and hyperplasia in cultured neonatal rat cardiac cells.

Molecular analysis of medicinally-used Chinese and Japanese Curcuma based on 18S rRNA gene and trnK gene sequences.

Curcuma drugs have been used discriminatingly for invigorating blood circulation, promoting digestion, and as a cholagogic in China. However, there is confusion about the drug's botanical origins and clinical uses because of morphological similarity of Curcuma plants and drugs. In order to develop an ultimate identification, molecular analysis based on 18S rRNA gene and trnK gene sequences were performed on 6 Curcuma species used medicinally in China and Japan. The 18S rRNA gene sequences were found to be of 1810 bps in length. In comparison with the common sequence of C. longa, C. phaeocaulis, C. wenyujin and C. aromatica, that of C. kwangsiensis had one base substitution, and the same base difference was observed between the Chinese and the Japanese populations of C. zedoaria. The trnK gene sequences were found to span 2698-2705 bps. There were base substitutions, small deletions or insertions at some sites between the trnK coding region and matK region among each species. Based on the base substitutions, C. zedoaria and C. kwangsiensis specimens were divided into two groups, respectively. An identical sequence was detected in C. phaeocaulis and in the Chinese population of C. zedoaria, as well as in the Japanese population of C. zedoaria and in one group of C. kwangsiensis with a purple-colored band in leaves. New taxonomic information to be used for authenticating Curcuma drugs was obtained.

Genetic heterogeneity of ribosomal RNA gene and matK gene in Panax notoginseng.

Previously, 185 ribosomal RNA gene and matK gene sequences of Chinese herbal medicines, Ginseng Radix, Panacis Japonici Rhizoma and Panacis Quinquefolli Radix were shown to correspond with those of the original plants, Panax ginseng, P. japonicus and P. quinquefolius, respectively, with the species-specific sequences especially for 18S rRNA gene sequences. In P. notoginseng and its derivative, Notoginseng Radix, however, we found two genetic groups with respect to both gene sequences. Five base substitutions were detected on both gene sequences and the homology between two groups was 99.7% for the 18S rRNA gene and 99.6% for the matK gene, respectively. One genetic group was found to have the identical sequences as those of P. ginseng.

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.

Dendrite extension by methanol extract of Ashwagandha (roots of Withania somnifera) in SK-N-SH cells.

Extension of dendrites and axons in neurons may compensate for and repair damaged neuronal circuits in the dementia brain. Our aim in the present study was to explore drugs activating neurite outgrowth and regenerating the neuronal network. We found that the methanol extract of Ashwagandha (roots of Withania somnifera; 5 microg/ml) significantly increased the percentage of cells with neurites in human neuroblastoma SK-N-SH cells. The effect of the extract was dose- and time-dependent mRNA levels of the dendritic markers MAP2 and PSD-95 by RT-PCR were found to be markedly increased by treatment with the extract, whereas those of the axonal marker Tau were not. Immunocytochemistry demonstrated the specific expression of MAP2 in neurites extended by the extract. These results suggest that the methanol extract of Ashwagandha promotes the formation of dendrites.

Inhibitory effect of Byakko-ka-ninjin-to on itch in a mouse model of atopic dermatitis.

Byakko-ka-ninjin-to (BN) is composed of gypsum, the root of anemarrhena, ginseng, licorice and rice. The effect of BN on the inhibition of itch was studied using an NC mouse model of atopic dermatitis. BN (200 mg/kg, p.o.) significantly inhibited the scratching frequency in NC mice, and decreased the skin temperature by 1.97 degrees C. The cooling action on the skin by BN may be involved in the inhibitory mechanism of itch, at least in part, since cooling the skin is known to inhibit the itch sensation in humans. Although the myocyte-specific enhancer binding factor 2C (MEF2C) mRNA is known to be increased in the cerebral cortex correlated with the itch sensation and skin lesions in NC mice, BN did not affect the expression level of the MEF2C mRNA. This result suggests that the inhibitory effect of BN on itch does not relate to inhibition of MEF2C expression in the cerebral cortex. The present study indicates that BN has an inhibitory effect on itch, and may be a useful antipruritic drug for atopic dermatitis.

Inhibitory effects of methanol extracts of herbal medicines on substance P-induced itch-scratch response.

In a search for new anti-pruritic drugs we screened methanol extracts of 33 herbal medicines which have been used for cutaneous diseases for their antipruritic activity using substance P (SP) as a pruritogen in mice. When administered perorally 30 min before SP injection, methanol extracts of 6 of these herbal medicines, the root of Scrophularia ningpoensis Hemsl., the root of Patrinia villosa (Thunb.) Juss, the fruit of Forsythia suspenna Vahl, the rhizome of Cimicifuga dahurica (Turcz.) Maxim., the aerial part of Schizonepeta tenuifolia Briq. and the fruit of Cnidium monnieri (L.) Cuss, inhibited SP-induced itch-scratch response at a dose of 200 mg/kg with-out affecting locomotor activity. Dose dependence of these 6 extracts (50-500 mg/kg) was investigated and all of them inhibited SP-induced itch-scratch response, with extracts from Scrophularia ningpoensis, Schizonepeta tenuifolia and Cnidium monnieri showing particularly significant inhibition. The results suggest that these 6 methanol extracts have inhibitory activity against SP-induced itching.

Guaiane dimers and germacranolide from Artemisia caruifolia.

One new germacranolide (named caruifolin A) and three new guaiane dimers (caruifolins B-D), together with six known compounds, were isolated from the aerial parts of Artemisia caruifolia. The structures were determined by chemical and spectroscopic methods.

Trigonelline-induced neurite outgrowth in human neuroblastoma SK-N-SH cells.

Extension of dendrites and axons in neurons may compensate and rescue damaged neuronal networks in the dementia brain. Our aim is to isolate and identify constituents of coffee beans exhibiting neurite outgrowth activity. Among the extracts of raw and roasted coffee beans, a methanol fraction of the ethanol extract (1 microg/ml) of raw beans increased significantly the percentage of cells with neurites in human neuroblastoma SK-N-SH cells. Among subfractions of this methanol fraction was a basic fraction (5 microg/ml) which exhibited significant neurite outgrowth activity. Finally, trigonelline in the basic fraction was identified to be active as far neurite extension was concerned. Treatment with trigonelline (30 microM) increased the percentage of cells with neurites at 3 and 6 d after treatment. In addition, the number of neurites reacting positively to phosphorylated neurofilament-H was increased by treatment with 30 microM trigonelline for 6 d, suggesting enhancement of axonal extension. These results show that trigonelline promotes functional neurite outgrowth.

Prolyl endopeptidase inhibitors from the underground part of Rhodiola sacra S. H. Fu.

Prolyl endopeptidase (PEP, EC 3.4.21.26) is an enzyme which plays a role in the metabolism of proline-containing neuropeptides, e.g., vasopressin, substance P and thyrotropin-releasing hormone (TRH), which have been suggested to be involved in learning and memory processes. In our systematic screening for PEP inhibitors from traditional Chinese medicines, we found that MeOH extract from the underground part of Rhodiola sacra S. H. Fu shows significant inhibitory activity against PEP from Flavobacterium meningosepticum. Examination of the constituents of the extract resulted in the isolation of nineteen known compounds, identified as hydroquinone (1), 4-hydroxybenzoic acid (2), caffeic acid (3), 4-hydroxycinnamic acid (4), suberic acid (5), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 2-phenylethyl beta-D-glucopyranoside (9), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), 2-phenylethyl alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside (11), sacranoside A (12), beta-D-glucopyranosyl 4-hydroxybenzoate (13), rhodiocyanoside A (14), rhodiooctanoside (15), sarmentosin (16), heterodendrin (17), arbutin (18) and 4-O-(beta-D-glucopyranosyl)-gallic acid (19). Among these, 1, 2, 5, 8-10, 13, 16, 18 and 19 have been isolated for the first time from R. sacra, among which 5, 9, 10, 13, 16, 18 and 19 have been isolated from Rhodiola plants for the first time. On the PEP inhibition, seven compounds (6-8, 10, 12, 18, 19) showed inhibition with an 1C50 of 27.8, 487, 1.47, 0.437, 348, 391 and 215 microM, respectively. The kinetic study of these inhibitors indicated that they are noncompetitive inhibitors, except for 6 which is a competitive inhibitor.

Pharmacological properties of traditional medicines. XXV. Effects of ephedrine, amygdalin, glycyrrhizin, gypsum and their combinations on body temperature and body fluid.

Effects of ephedrine, amygdalin, glycyrrhizin, gypsum and their combinations on body temperature and body fluid were studied in rats using the method developed in our previous reports. Ephedrine significantly increased respiratory evaporative water loss and heat loss in response to a marked elevation of body temperature. There was a small but significant increase in body temperature when amygdalin was orally given rats at a dose of 46.32 mg/kg. Glycyrrhizin and gypsum were unable to affect body temperature. However, gypsum was able to prevent the increased action of ephedrine on body temperature, amygdalin exhibited a preventive tendency to it, and glycyrrhizin did not affect it. The results are in good agreement with classical claims of Makyo-kanseki-to and the related crude drugs in traditional medicine. Moreover, a combination of the four components reproduced the effects of Makyo-kanseki-to on body temperature and body fluid. This report suggests that the co-administration of ephedrine and gypsum is physiologically more desirable than ephedrine alone for dry-type asthmatic patients with a fever. Also, it experimentally supports the clinical efficacy of Makyo-kanseki-to.

A new flavanone isolated from rhizoma smilacis glabrae and the structural requirements of its derivatives for preventing immunological hepatocyte damage.

From the rhizome of Smilax glabra Roxb., a new flavanone was isolated and named as smitilbin (1), together with 6 known compounds, engeletin (2), astilbin (3), dihydroquercetin (4), eurryphin (5), resveratrol (6), and 5-O-caffeoylshikimic acid (7). These compounds were applied to the assay of liver nonparenchymal cells (NPC) against hepatocytes (HC) isolated from mice with an immunological liver injury. Against the NPC-caused elevation of ALT (alanine transminase) in culture supernatant from HC, the pretreatment of NPC with flavanoids (1-3) dose-dependently blocked the ALT release while 4, the aglycone of 3, did not. The chromone 5 showed a much stronger inhibition. Compound 6 also showed the activity. However, 1-7 did not show any suppression of NPC or CCl4-induced ALT release when they were used to pretreat HC. These results suggest that compounds 1-3, 5, and 6 could protect the hepatocyte damage from NPC through selectively producing the dysfunction of NPC with an essential requirement of rhamnose, and the chromone part in their structures may be critical for exhibiting the activity rather than through protecting the hepatocyte membranes.

Active-oxygen scavenging activity of traditional nourishing-tonic herbal medicines and active constituents of Rhodiola sacra.

The active-oxygen scavenging activity of 70 traditional herbal medicines used in China and Japan as nourishing tonics were evaluated by electron spin resonance (ESR) technique, in order to evaluate their effectiveness for anti-aging and to search for new active-oxygen scavengers from natural resources. Most of the 70 herbal medicines showed scavenging activity with various intensities. Areca catechu (methanol extract), Dendrobium plicatile (methanol extract), Juglans regia (water extract), Paeonia lactiflora (methanol extract), Psychotria serpens (water and methanol extracts), Rhodiola sacra (water and methanol extracts) and Uncaria rhynchophylla (water extract) especially showed strong scavenging activity against superoxide anion radical (*O2-), while J. regia (water and methanol extracts), Morus alba (water extract) and Schisandra chinensis (water extract) revealed strong scavenging activity against hydroxyl radical (HO*). In addition, the active-oxygen scavenging activities of 19 compounds isolated from R. sacra were also examined, and hydroquinone (1), caffeic acid (3), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), heterodendrin (17) and gallic acid 4-O-beta-D-glucopyranoside (19) were found to show mild or strong inhibitory activity against superoxide anion radical (*O2-), while 4-hydroxybenzoic acid (2), 3, 4-hydroxycinnamic acid (4), 6-8 and 19 inhibited hydroxyl radical (OH*). These active-oxygen scavengers may contribute, to different extents, to their anti-aging action.