Potential effects of medicinal plants and secondary metabolites on acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. ALI is characterized by increased permeability of the alveolar-capillary membrane, edema, uncontrolled neutrophils migration to the lung, and diffuse alveolar damage, leading to acute hypoxemic respiratory failure. Although corticosteroids remain the mainstay of ALI treatment, they cause significant side effects. Agents of natural origin, such as medicinal plants and their secondary metabolites, mainly those with very few side effects, could be excellent alternatives for ALI treatment. Several studies, including our own, have demonstrated that plant extracts and/or secondary metabolites isolated from them reduce most ALI phenotypes in experimental animal models, including neutrophil recruitment to the lung, the production of pro-inflammatory cytokines and chemokines, edema, and vascular permeability. In this review, we summarized these studies and described the anti-inflammatory activity of various plant extracts, such as Ginkgo biloba and Punica granatum, and such secondary metabolites as epigallocatechin-3-gallate and ellagic acid. In addition, we highlight the medical potential of these extracts and plant-derived compounds for treating of ALI.

The tannosome is an organelle forming condensed tannins in the chlorophyllous organs of Tracheophyta

BACKGROUND AND AIMS

Condensed tannins (also called proanthocyanidins) are widespread polymers of catechins and are essential for the defence mechanisms of vascular plants (Tracheophyta). A large body of evidence argues for the synthesis of monomeric epicatechin on the cytosolic face of the endoplasmic reticulum and its transport to the vacuole, although the site of its polymerization into tannins remains to be elucidated. The aim of the study was to re-examine the cellular frame of tannin polymerization in various representatives of the Tracheophyta.

METHODS

Light microscopy epifluorescence, confocal microscopy, transmission electron microscopy (TEM), chemical analysis of tannins following cell fractionation, and immunocytochemistry were used as independent methods on tannin-rich samples from various organs from Cycadophyta, Ginkgophyta, Equisetophyta, Pteridophyta, Coniferophyta and Magnoliophyta. Tissues were fixed in a caffeine-glutaraldehyde mixture and examined by TEM. Other fresh samples were incubated with primary antibodies against proteins from both chloroplastic envelopes and a thylakoidal chlorophyll-carrying protein; they were also incubated with gelatin-Oregon Green, a fluorescent marker of condensed tannins. Coupled spectral analyses of chlorophyll and tannins were carried out by confocal microscopy on fresh tissues and tannin-rich accretions obtained through cell fractionation; chemical analyses of tannins and chlorophylls were also performed on the accretions.

KEY RESULTS AND CONCLUSIONS

The presence of the three different chloroplast membranes inside vacuolar accretions that constitute the typical form of tannin storage in vascular plants was established in fresh tissues as well as in purified organelles, using several independent methods. Tannins are polymerized in a new chloroplast-derived organelle, the tannosome. These are formed by pearling of the thylakoids into 30 nm spheres, which are then encapsulated in a tannosome shuttle formed by budding from the chloroplast and bound by a membrane resulting from the fusion of both chloroplast envelopes. The shuttle conveys numerous tannosomes through the cytoplasm towards the vacuole in which it is then incorporated by invagination of the tonoplast. Finally, shuttles bound by a portion of tonoplast aggregate into tannin accretions which are stored in the vacuole. Polymerization of tannins occurs inside the tannosome regardless of the compartment being crossed. A complete sequence of events apparently valid in all studied Tracheophyta is described.

[Leaf micro-morphology and features in adsorbing air suspended particulate matter and accumulating heavy metals in seven trees species]

The purpose of this study was to assess the relationship between tree leaf micro-morphology and features in adsorbing air suspended particulate matter and accumulating heavy metals. Seven tree species, including Ginkgo biloba, at heavy traffic density site in Huainan were selected to analyze the frequency of air particulate matter retained by leaves, the particle amount of different sizes per unit leaf area retained by leaves and its related micro-morphology structure, and the relationship between particle amount of different sizes per unit leaf area retained by leaves and its related accumulation of heavy metals. We found that the species characterized by small leaf area, special epidemis with abundant fax, and highly uneven cell wall, as well as big and dense stomata and without trichomes mainly absorbed fine particulate matter; while those species with many trichomes mainly retained coarse particulate matter. Accumulation of heavy metals in leaves of the seven species was significantly different except for Ph. Tree species with high capacities in heavy metal accumulation were Ginkgo biloba, Ligustrum lucidum, and Cinnamomum camphora. Accumulation of Cd, Cr, Ni, Zn, Cu and total heavy metal concentration for seven tree species was positively related to the amount of particulate matter absorbed. Correlation coefficients of d10 vs d2.5, d10 vs d1.0, d2.5 vs d1.0 were 0.987, 0.971, 0.996, respective, and the correlate level was significant. The ratios of d2.5/d10, d1.0/d10, d1.0/d2.5 were 0.844, 0.763, 0.822, indicating that the particulate matter from traffic was mainly fine particulates.

Expression patterns of an isoflavone reductase-like gene and its possible roles in secondary metabolism in Ginkgo biloba

Our results showed that GbIRL1 belongs to the PCBER protein family. Besides, IRL1 gene was a novel gene regulating lignin change and also effecting the accumulation of flavonoids in Ginkgo. A cDNA encoding the IFR-like protein was isolated from the leaves of Ginkgo biloba L., designated as GbIRL1 (Accession no. KC244282). The cDNA of GbIRL1 was 1,203 bp containing a 921 bp open reading frame encoding a polypeptide of 306 amino acids. Comparative and bioinformatic analyses revealed that GbIRL1 showed extensive homology with IFLs from other gymnosperm species. Phylogenetic tree analysis revealed that GbIRL1 shared the same ancestor in evolution with other PCBERs protein and had a further relationship with other gymnosperm species. The recombinant protein was successfully expressed in E. coli strain with pET-28a vector. The vitro enzyme activity assay by HPLC indicated that recombinant GbIRL1 protein could catalyze the formation the TDDC, IDDDC from DDDC, DDC. Tissue expression pattern analysis showed that GbIRL1 was constitutively expressed in stem and roots, especially in the parts of the pest and fungal infection, with the lower expression being found in 1- or 2-year old stem. The increased expression of GbIRL1 was detected when the seedlings were treated with Ultraviole-B, ALA, wounding and ethephon, abscisic acid, salicylic acid. Correlation analysis between GbIRL1 activity and flavonoid accumulation during Ginkgo leaf growth indicated that GbIRL1 might be the rate-limiting enzyme in the biosynthesis pathway of flavonoids in Ginkgo leaves. Results of RT-PCR analysis showed that the transcription level of change in GbIRL1 power correlated with flavonoid contents, suggesting IRL1 gene as a novel gene regulating lignin change and also effecting the accumulation of flavonoids in Ginkgo.

[Chlorophyll fluorescence transient kinetics of ginkgo leaves during expansion]

OBJECTIVE

To provide the theoretical basis for cultivating ginkgo (Ginkgo biloba).

METHODS

Changes of chlorophyll fluorescence transient kinetics in chloroplasts of 10-year-old seeded ginkgo leaves during expansion were studied in the field under natural environmental conditions.

RESULTS

W(k) peaked between 12: 00 - 15: 00, phiE(o) and psi(o) declined gradually between 8: 00 - 12: 00. ABS/ RC,TR(o)/RC and DI(o)/RC increased, while RC/CS decreased at noon. PI(abs) and F(v)/F(m) declined and reached its lowest value at 13:00, then increased, and the levels at 19:00 could restore to the levels at 7: 00.

CONCLUSION

The donor and acceptor sides of PS II are temporarily inhibited. The reaction centers of PS II are damaged, leading to the light energy transfer efficiency of PS II decrease and excess excitation energy increase at noon. The damage of reaction centers of PS II and inhibition of photosynthetic primary reaction are reversible inactivation not irreversible damaged.

Ginkgo biloba responds to herbivory by activating early signaling and direct defenses

Background

Ginkgo biloba (Ginkgoaceae) is one of the most ancient living seed plants and is regarded as a living fossil. G. biloba has a broad spectrum of resistance or tolerance to many pathogens and herbivores because of the presence of toxic leaf compounds. Little is known about early and late events occurring in G. biloba upon herbivory. The aim of this study was to assess whether herbivory by the generalist Spodoptera littoralis was able to induce early signaling and direct defense in G. biloba by evaluating early and late responses.

Methodology/Principal Findings

Early and late responses in mechanically wounded leaves and in leaves damaged by S. littoralis included plasma transmembrane potential (Vm) variations, time-course changes in both cytosolic calcium concentration ([Ca²⁺]_cyt) and H₂O₂ production, the regulation of genes correlated to terpenoid and flavonoid biosynthesis, the induction of direct defense compounds, and the release of volatile organic compounds (VOCs). The results show that G. biloba responded to hebivory with a significant Vm depolarization which was associated to significant increases in both [Ca²⁺]_cyt and H₂O₂. Several defense genes were regulated by herbivory, including those coding for ROS scavenging enzymes and the synthesis of terpenoids and flavonoids. Metabolomic analyses revealed the herbivore-induced production of several flavonoids and VOCs. Surprisingly, no significant induction by herbivory was found for two of the most characteristic G. biloba classes of bioactive compounds; ginkgolides and bilobalides.

Conclusions/Significance

By studying early and late responses of G. biloba to herbivory, we provided the first evidence that this “living fossil” plant responds to herbivory with the same defense mechanisms adopted by the most recent angiosperms.

Mutagenic and morphologic impacts of 1.8GHz radiofrequency radiation on human peripheral blood lymphocytes (hPBLs) and possible protective role of pre-treatment with Ginkgo biloba (EGb 761)

The mutagenic and morphologic effects of 1.8GHz Global System for Mobile Communications (GSM) modulated RF (radiofrequency) radiation alone and in combination with Ginkgo biloba (EGb 761) pre-treatment in human peripheral blood lymphocytes (hPBLs) were investigated in this study using Sister Chromatid Exchange (SCE) and electron microscopy. Cell viability was assessed with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) reduction assay. The lymphocyte cultures were exposed to GSM modulated RF radiation at 1.8GHz for 6, 8, 24 and 48h with and without EGb 761. We observed morphological changes in pulse-modulated RF radiated lymphocytes. Longer exposure periods led to destruction of organelle and nucleus structures. Chromatin change and the loss of mitochondrial crista occurred in cells exposed to RF for 8h and 24h and were more pronounced in cells exposed for 48h. Cytoplasmic lysis and destruction of membrane integrity of cells and nuclei were also seen in 48h RF exposed cells. There was a significant increase (p<0.05) in SCE frequency in RF exposed lymphocytes compared to sham controls. EGb 761 pre-treatment significantly decreased SCE from RF radiation. RF radiation also inhibited cell viability in a time dependent manner. The inhibitory effects of RF radiation on the growth of lymphoctes were marked in longer exposure periods. EGb 761 pre-treatment significantly increased cell viability in RF+EGb 761 treated groups at 8 and 24h when compared to RF exposed groups alone. The results of our study showed that RF radiation affects cell morphology, increases SCE and inhibits cell proliferation. However, EGb 761 has a protective role against RF induced mutagenity. We concluded that RF radiation induces chromosomal damage in hPBLs but this damage may be reduced by EGb 761 pre-treatment.

Diet and thrombosis risk: nutrients for prevention of thrombotic disease

An increased prothrombotic state is a major risk factor for the development of heart attacks, strokes, and venous thromboembolism. Platelet activation and aggregation play an important role in determining a prothrombotic state. Although pharmaceutical agents such as aspirin, heparin, and warfarin are able to reduce prothrombotic tendency, long-term drug treatment may produce a variety of side effects, including bleeding. Diet is generally recognized to be significantly involved in modifying the individual risk for the development of thrombotic diseases, although its influence during the treatment of these disorders is probably less important. Dietary intervention has proven effective in lowering serum lipid levels, which are otherwise essential elements in the pathogenesis of cardiovascular disease. Likewise, certain dietary components have also been proven effective in decreasing platelet activation through various mechanisms and therefore may contribute to attenuating the future risk of thrombosis. This article provides an up-to-date review of the role of nutrient and nonnutrient supplements on platelet aggregation and risk of thrombosis.

The extract of Ginkgo biloba EGb 761 reactivates a juvenile profile in the skeletal muscle of sarcopenic rats by transcriptional reprogramming

Background

Sarcopenia is a major public health problem in industrialized nations, placing an increasing burden on public healthcare systems because the loss of skeletal muscle mass and strength that characterizes this affection increases the dependence and the risk of injury caused by sudden falls in elderly people. Albeit exercise and caloric restriction improve sarcopenia-associated decline of the muscular performances, a more suitable and focused pharmacological treatment is still lacking.

Methodology/Principal Findings

In order to evaluate such a possible treatment, we investigated the effects of EGb 761, a Ginkgo biloba extract used in chronic age-dependent neurological disorders, on the function of the soleus muscle in aged rats. EGb 761 induced a gain in muscular mass that was associated with an improvement of the muscular performances as assessed by biochemical and electrophysiological tests. DNA microarray analysis shows that these modifications are accompanied by the transcriptional reprogramming of genes related to myogenesis through the TGFβ signaling pathway and to energy production via fatty acids and glucose oxidation. EGb 761 restored a more juvenile gene expression pattern by regenerating the aged muscle and reversing the age-related metabolic shift from lipids to glucose utilization.

Conclusions/Significance

Thus, EGb 761 may represent a novel treatment for sarcopenia both more manageable and less cumbersome than exercise and caloric restriction.

Fungal endophytes-induced abscisic acid is required for flavonoid accumulation in suspension cells of Ginkgo biloba

Treatment of suspension cells of Ginkgo biloba with fungal endophytes resulted in accumulation of flavonoids, increased abscisic acid (ABA) production and activation of phenylalanine ammonia-lyase (PAL). Fluridone, an inhibitor of ABA biosynthesis, was effective in inhibiting fungal endophytes-induced ABA biosynthesis, increase of PAL activity and flavonoids accumulation. Moreover, exogenous application of ABA enhanced PAL activity and increased accumulation of flavonoids in G. biloba cells with or without fungal endophytes elicitor. These finding suggest a causal relationship between ABA release and both PAL activity and flavonoid accumulation under fungal endophytes treatment and that ABA is involved in fungal endophytes-induced flavonoids accumulation in this plant.

Complementary action of jasmonic acid on salicylic acid in mediating fungal elicitor-induced flavonol glycoside accumulation of Ginkgo biloba cells

The antagonistic action between jasmonic acid (JA) and salicylic acid (SA) in plant defence responses has been well documented. However, their relationship in secondary metabolite production is largely unknown. Here, we report that PB90, a protein elicitor from Phytophthora boehmeriae, triggers JA generation, SA accumulation and flavonol glycoside production of Ginkgo biloba cells. JA inhibitors suppress not only PB90-triggered JA generation, but also the elicitor-induced flavonol glycoside production. However, the elicitor can still enhance flavonol glycoside production even though the JA generation is totally inhibited. Over-expression of SA hydrolase gene NahG not only abolishes SA accumulation, but also suppresses the elicitor-induced flavonol glycoside production when JA signalling is inhibited. Interestingly, expression of NahG does not inhibit the elicitor-induced flavonol glycoside accumulation in the absence of JA inhibitors. Moreover, JA levels are significantly enhanced when SA accumulation is impaired in the transgenic cells. Together, the data suggest that both JA and SA are involved in PB90-induced flavonol glycoside production. Furthermore, we demonstrate that JA signalling might be enhanced to substitute for SA to mediate the elicitor-induced flavonol glycoside accumulation when SA signalling is impaired, which reveals an unusual complementary relationship between JA and SA in mediating plant secondary metabolite production.

[Studies on dynamic change of total ginkgolic acids in Ginkgo biloba leaves of different aged trees and different collecting seasons]

OBJECTIVE

To study dynamic change of total ginkgolic acids in Ginkgo biloba leaves of the different aged trees and different collecting seasons.

METHOD

The content of total ginkgolic acids in G. biloba leaves was determined by HPLC. A Alltima C18 (4.6 mm x 250 mm, 5 microm) and the mobile phase of methanol and 1% acetic acid (90:10) were used, the flow rate was 1.0 mL x min(-1), and the wavelength was 310 nm. The content were calculated with external standard method.

RESULT

The content of total ginkgolic acids in G. biloba leaves was in the range of 0.48% to 2.51% in different collecting seasons. The content reached maximum at the end of May and the beginning of June, and then declined gradually. In different aged trees, the content in the older ages was lower than that in the younger ages.

CONCLUSION

The results provide scientific basis for the collecting season of G. biloba leaves.

Impact of elevated CO2 and O3 concentrations on biogenic volatile organic compounds emissions from Ginkgo biloba

In natural environment with ambient air, ginkgo trees emitted volatile organic compounds 0.18 microg g(-1) h(-1) in July, and 0.92 microg g(-1) h(-1) in September. Isoprene and limonene were the most abundant detected compounds. In September, alpha-pinene accounted for 22.5% of the total. Elevated CO(2) concentration in OTCs increased isoprene emission significantly in July (p<0.05) and September (p<0.05), while the total monoterpenes emission was enhanced in July and decreased in September by elevated CO(2). Exposed to elevated O(3) increased the isoprene and monoterpenes emissions in July and September, and the total volatile organic compounds emission rates were 0.48 microg g(-1) h(-1) (in July) and 2.24 microg g(-1) h(-1) (in September), respectively. The combination of elevated CO(2) and O(3) did not have any effect on biogenic volatile organic compounds emissions, except increases of isoprene and Delta3-carene in September.

[Effects of root-excision on trunk hydraulic traits and growth status of Ginkgo biloba]

The roots of 8-year-old Ginkgo biloba saplings were partially excised to three degrees to study the effects of root-excision on the trunk hydraulic traits and growth status of the saplings. The three degrees were severe, medium, and light (8:1, 10:1, and 12:1 of excised root diameter to base diameter of tree trunk, respectively). Physiological parameters including trunk ultrasound acoustic emission (UAE) signal, branch percentage loss of hydraulic conductance (PLC), sap flow flux, and leaf stomatal conductance, transpiration rate and water potential were measured periodically after root-excision. In all treatments, a great number of trunk UAE signal produced after a short time of root-excision, peaked at 6 h, and decreased gradually then. The intensity of the UAE signals increased with increasing root-excision degree. After root-excision, the branch PLC increased rapidly in the first 12 h but slowly after 24 h. The sap flow flux, leaf stomatal conductance, transpiration rate and water potential after root-excision decreased obviously, with significant differences among the three treatments. The cumulative number of UAE signals (cUAE) was significantly and positively correlated with branch embolism degree, while negatively correlated with sap flow flux and leaf water potential. The leaf area and new branch length of G. biloba in the next year after root-excision decreased significantly, and the decrement was increased with root-excision degree. Root-excision not only made the degrees of conduits cavitation and branch embolism increased, but also affected water transportation and leaf transpiration rate within a short period of time, which would in turn give an impact on G. biloba plant growth.

To compare the efficacy and safety of nifedipine sustained release with Ginkgo biloba extract to treat patients with primary Raynaud's phenomenon in South Korea; Korean Raynaud study (KOARA study)

This study examined the efficacy and safety of nifedipine sustained release (nifedipine SR) compared with Ginkgo biloba extract as treatment for primary Raynaud's phenomenon (RP) in Korea. Primary RP were screened and assigned to either the nifedipine SR group (Group N) or the Ginkgo biloba extract group (Group G) in the ratio of 2:1. After a run-in period of 2 weeks, patients received treatment for 8 weeks. We observed the percent improvement of the RP attack rate between before and after the 8-week treatment. Ninety-three subjects were randomly assigned. The percent improvement in Group N was 50.1% at 8 weeks after treatment, while it was 31.0% in Group G (p = 0.03). No serious adverse events occurred, and almost adverse events were mild and improved without specific treatment. nifedipine SR was more effective than Ginkgo biloba extract for treatment of primary RP in Korean patients. Both drugs were tolerable with primary RP patients.

Changes of main secondary metabolites in leaves of Ginkgo biloba in response to ozone fumigation

To investigate the effect of elevated O3 on the accumulation of main secondary metabolites in leaves of Ginkgo biloba L., four-year-old trees were exposed in open-top chambers with ambient air and the air with twice ambient O3 concentration in Shenyang in 2006. Elevated O3 increased the concentrations of terpenes, but decreased the concentrations of phenolics in G. biloba leaves. The results showed that secondary compounds from G. biloba leaves responded to the elevated O3 exposure in a different way when compared to previous studies which showed elevated O3 increased the concentrations of phenolics but had no effect on the terpenes in leaves of other deciduous trees. Furthermore, reduced synthesis of phenolics may decrease the resistance of G. biloba to O3 and other environmental factors. On the other hand, the induced synthesis of terpenes may enhance the antioxidant abilities in G. biloba leaves at the end of O3 fumigation.

Light and temperature regulation of greening in dark-grown ginkgo (Ginkgo biloba)

The last steps of chlorophyll (Chl) biosynthesis were studied at different light intensities and temperatures in dark-germinated ginkgo (Ginkgo biloba L.) seedlings. Pigment contents and 77 K fluorescence emission spectra were measured and the plastid ultrastructure was analysed. All dark-grown organs contained protochlorophyllide (Pchlide) forms with similar spectral properties to those of dark-grown angiosperm seedlings, but the ratios of these forms to each other were different. The short-wavelength, monomeric Pchlide forms were always dominating. Etioplasts with small prolamellar bodies (PLBs) and few prothylakoids (PTs) differentiated in the dark-grown stems. Upon illumination with high light intensities (800 micromol m(-2) s(-1) photon flux density, PFD), photo-oxidation and bleaching occurred in the stems and the presence of (1)O(2) was detected. When Chl accumulated in plants illuminated with 15 micromol m(-2) s(-1) PFD it was significantly slower at 10 degrees C than at 20 degrees C. At room temperature, the transformation of etioplasts into young chloroplasts was observed at low light, while it was delayed at 10 degrees C. Grana did not appear in the plastids even after 48 h of greening at 20 degrees C. Reaccumulation of Pchlide forms and re-formation of PLBs occurred when etiolated samples were illuminated with 200 micromol m(-2) s(-1) PFD at room temperature for 24 h and were then re-etiolated for 5 days. The Pchlide forms appeared during re-etiolation had similar spectral properties to those of etiolated seedlings. These results show that ginkgo seedlings are very sensitive to temperature and light conditions during their greening, a fact that should be considered for ginkgo cultivation.

Influence of elevated carbon dioxide and ozone on the foliar nonvolatile terpenoids in ginkgo biloba

The aim of this study was to determine the effects of elevated O(3) and elevated CO(2,) singly and in combination, on the contents of nonvolatile terpenoids in leaves of Ginkgo Biloba. The results showed that elevated CO(2), alone and in combination with elevated O(3) increased concentrations of all the determined terpenoids, while elevated O(3) alone only increased concentration of bilobalide. These results demonstrated that the metabolism of terpenoids in ginkgo leaves was more sensitive to elevated CO(2) than elevated O(3).

Two copies of 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol kinase (CMK) gene in Ginkgo biloba: molecular cloning and functional characterization

4-(Cytidine 5'-diphospho)-2-C-methyl-D-erythritol kinase (CMK or YchB), the fourth enzyme of the 2-C-methyl-D-erythritol 4-phosphate pathway, phosphorylates the 2-hydroxyl group of 4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol in the presence of ATP. Two isogenes encoding CMK (GbCMK1 and GbCMK2) were cloned and characterized from Ginkgo biloba. The activities of both isozymes were confirmed by complementation assay using Escherichia coli NMW29, a ychB knock-out mutant. The transcript profiles of GbCMKs in the radicles and the cotyledons of the cultured Ginkgo biloba embryos demonstrated that the transcript levels of GbCMK1 were similar in both organs, whereas that of GbCMK2 was predominantly high in the ginkgolide-synthesizing radicles. Selective increases in the transcript abundance of GbCMK2 in the radicles, induced by light and methyl jasmonate treatments, were observed. These differential induction patterns of the transcripts imply GbCMK1 and GbCMK2 respectively have high correlations with the primary and the secondary metabolisms. The transit peptides of both isozymes delivered the fused green fluorescent protein (GFP) into the chloroplast in the Arabidopsis and the Nicotiana transient expression systems; interestingly, the transit peptide of GbCMK1 delivered the GFP protein into the cytosol and the nucleus in addition to the chloroplasts.

Purified polysaccharide from Ginkgo biloba leaves inhibits P-selectin-mediated leucocyte adhesion and inflammation

AIM

To investigate the anti-inflammatory mechanism of the polysaccharides of Ginkgo biloba leaves (PGBL) by inhibiting leucocyte adhesion.

METHODS

The rough PGBL were isolated and purified. The anti-inflammatory effects of purified PGBL (p-PGBL) were assayed by ear edema induced by xylol and the acute peritonitis model in mice. The effect of p-PGBL on inhibiting the interaction between P-selectin and its ligands was investigated by flow cytometry and flow chamber.

RESULTS

p-PGBL could effectively inhibit the acute inflammation in mice and interfere with the adhesion of HL-60 cells, a human leukaemia cell line, or neutrophils to P-selectin in static conditions, as well as the adhesion of neutrophils to Chinese hamster ovary cells expressing human P-selectin and human umbilical vein endothelial cells in flow conditions in a dose-dependant manner.

CONCLUSIONS

p-PGBL can inhibit the inflammatory process through interfering with the interaction between P-selectin and its ligands.

[Effects of elevated O3 on the volatile organic compounds emit from Ginkgo biloba and Pinus tabulaeformis]

To study the impact of elevated tropospheric O3 concentrations on BVOCs emissions by Pinus tabulaeformis and Ginkgo biloba in urban area, the trees were exposed in open-top chambers. Two ozone treatments were established: ambient air (approximately 30 nmol x mol(-1) ) (CK) and elevated O3 concentrations (80 nmol x mol(-1) ) (O3 ). Elevated O3 concentrations significantly induced isoprene to emit for Pinus tabulaeformis and Ginkgo biloba (p < 0.05), and delta3-carene for Ginkgo biloba (p < 0.05). The emission rates were increased to 1.96, 9.71 and 0.09 microg/(g x h) (-1), respectively. There were no significant differences between ozone fumigation treatments for the other monoterpenes. At the same time, the relative abundances of the monoterpenes and isoprene were to be different between tree species and effect by O3 exposure. In CK chambers, the dominate BVOCs emitted by Ginkgo biloba was isoprene, and a-pinene for Pinus tabulaeformis. In the elevated O3 chambers, the isoprene accounted for 64.73% of Pinus tabulaeformis BVOCs. To sum up, the BVOCs emitting patterns were influenced by elevated O3 significantly.

Effect of Ginkgo biloba extract on lopinavir, midazolam and fexofenadine pharmacokinetics in healthy subjects

OBJECTIVE

Animal and in vitro data suggest that Ginkgo biloba extract (GBE) may modulate CYP3A4 activity. As such, GBE may alter the exposure of HIV protease inhibitors metabolized by CYP3A4. It is also possible that GBE could alter protease inhibitor pharmacokinetics (PK) secondary to modulation of P-glycoprotein (P-gp). The primary objective of the study was to evaluate the effect of GBE on the exposure of lopinavir in healthy volunteers administered lopinavir/ritonavir. Secondary objectives were to compare ritonavir exposure pre- and post-GBE, and assess the effect of GBE on single doses of probe drugs midazolam and fexofenadine.

METHODS

This open-label study evaluated the effect of 2 weeks of standardized GBE administration on the steady-state exposure of lopinavir and ritonavir in 14 healthy volunteers administered lopinavir/ritonavir to steady-state. In addition, single oral doses of probe drugs midazolam and fexofenadine were administered prior to and after 4 weeks of GBE (following washout of lopinavir/ritonavir) to assess the influence of GBE on CYP3A and P-gp activity, respectively.

RESULTS

Lopinavir, ritonavir and fexofenadine exposures were not significantly affected by GBE administration. However, GBE decreased midazolam AUC(0-infinity) and C(max) by 34% (p = 0.03) and 31% (p = 0.03), respectively, relative to baseline. In general, lopinavir/ritonavir and GBE were well tolerated. Abnormal laboratory results included mild elevations in hepatic enzymes, cholesterol and triglycerides, and mild-to-moderate increases in total bilirubin.

CONCLUSIONS

Our results suggest that GBE induces CYP3A metabolism, as assessed by a decrease in midazolam concentrations. However, there was no change in the exposure of lopinavir, likely due to ritonavir's potent inhibition of CYP3A4. Thus, GBE appears unlikely to reduce the exposure of ritonavir-boosted protease inhibitors, while concentrations of unboosted protease inhibitors may be affected. Limitations to our study include the single sequence design and the evaluation of a ritonavir-boosted protease inhibitor exclusively.

[Exogenous nitric oxide accelerates soluble sugar, proline and secondary metabolite synthesis in Ginkgo biloba under drought stress]

The effects of exogenous nitric oxide donor sodium nitroprusside (SNP) on substance metabolism of Ginkgo biloba leaves under drought stress were studied. The results showed that 250 micromol/L SNP (Fig.2) treatment under 35% relative soil water content (RSWC) stress (Fig.1) raised remarkably soluble sugar content (Fig.3), proline content (Fig.4), phenylalanine ammonia lyase (PAL) activity (Fig.5), flavonoids (Fig.6) and ginkgolides content (Fig.7) of G. biloba leaves. Hemoglobin, used as NO scavenger, counteracted the effects of SNP in raising the soluble sugar (Fig.3), proline (Fig.4), flavonoid (Fig.6), ginkgolide content (Fig.7) and PAL activities (Fig.5), which indicates that the effects of sodium nitroprusside were through the nitric oxide released from sodium nitroprusside. We propose from these results that the roles of flavonoids and ginkgolides are the same as those of soluble sugars and proline under drought stress. NO may alleviate the damage caused by drought stress through raising soluble sugar, proline, flavonoid and ginkgolide content.

Analysis of flavonol aglycones and terpenelactones in Ginkgo biloba extract: A comparison of high-performance thin-layer chromatography and column high-performance liquid chromatography

Advancements in automated high-performance thin-layer chromatography (HPTLC) have made it feasible to assess its use for the quantitative analysis of marker compounds in botanical preparations. We report here the findings of method comparisons for the terpenelactones and flavonol aglycones by column high-performance liquid chromatography (HPLC) with evaporative light scattering and UV detection, and HPTLC with a scanning densitometer. For the HPTLC assay of terpenelactones, total bilobalide, ginkgolide A, and ginkgolide B consistently achieved <70% of the total determined using HPLC, regardless of variations to postchromatographic derivatization time and temperature. Accuracy testing showed the possibility of a matrix interference. In contrast, a good relationship (95%) was determined between HPTLC and HPLC for determination of total flavonol glycosides (calculated from combined quercetin, kaempferol, and isorhamnetin) from an acid-hydrolyzed Ginkgo biloba L. (GBE) sample. The HPTLC flavonol aglycone method also performed well in terms of accuracy (overall average of 96% recovery for the 3 aglycones) and consecutive plate repeatability (overall percent relative standard deviation of 4.4). It is demonstrated that HPTLC can be a time-saving complement to HPLC for routine analysis of the flavonol glycosides in GBE.

Hydraulic design of leaves: insights from rehydration kinetics

We examined the leaf hydraulic design in 10 species based on their rehydration kinetics. In all cases, a biphasic response described the temporal pattern of water uptake, with time constants of approximately 30 to 800 s and approximately 800 to 8000 s. The time constants of the fast phase were significantly shorter in the six angiosperms (30 to 110 s) compared with the two single-veined conifer species (>400 s) examined, while the two multi-veined gymnosperm species, Gnetum gnemon and Ginkgo biloba, had time constants for the fast phase of approximately 150 s. Among angiosperm species, the fast phase constituted 50-90% of the total water absorbed, whereas in gymnosperms 70-90% of the water uptake could be assigned to the slow phase. In the four gymnosperms, the relative water uptake corresponding to the fast phase matched to a good degree the relative volume of the venation and bundle sheath extension; whereas in the angiosperm species, the relatively larger water influx during the fast phase was similar in relative volume to the combined venation, bundle sheath extension, epidermis and (in four species) the spongy mesophyll. This suggests a general trend from a design in which the epidermis is weakly connected to the veins (all four gymnosperms), to a design with good hydraulic connection between epidermis and veins that largely bypasses the mesophyll (four of six angiosperms), to a design in which almost the entire leaf appears to function as a single pool.