Mechanisms of active fraction combination from Liuwei Dihuang Decoction(LW-AFC) on long-term potentiation impairment in vivo

OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kidney yin deficiency in many animal models.This study evaluated the effects and mechanisms of LW-AFC and the active fractions on corticosterone(Cort)-induced long-term potentiation(LTP)impairment in vivo.METHODS LTP was used to evaluate the synaptic plasticity.LW-AFC was orally administered for seven days.The active fractions were given by either chronic administration(ig,ip,7 d)or single administration(icv,ig,ip).Cort was injected subcutaneously 1h before the high-frequency stimulation(HFS)to induce LTP impairment.Moreover,in order to research on the possible effective pathways,an antibiotic cocktail and an immunosuppressant were also used.RESULTS Chronic administration(ig)of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Single administration(icv,ig,ip)of any of the active fractions had no effect on Cort-induced LTP impairment,while chronic administration(ig,ip)of LWB-B or LWD-b showed positive effects against Cort.Interestingly,CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition,when the intestinal microbiota was disrupted by application of the antibiotic cocktail,CA-30 showed little protective effects against Cort.The effects of LW-AFC were also abolished when the immune function was inhibited.In the hippocampal tissue,Cort treatment increased Cort and glutamate,and LW-AFC could inhibit the Cort-induced elevation of Cort and glutamate;there was little change in D-serine in Cort-treated animals,but LW-AFC could increase the D-serine levels.CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Their protective effects are unlikely by a direct way,and immune modulation might be the common pathway.CA-30 could protect LTP from impairment via modulating the intestinal microbiota.Decreasing Cort and glutamate and increasing D-serine in the Cort-treated animals'hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC.Further study is needed to understand the underlying mechanisms.

Screening of active fractions from Radix of Actinidiae chinensis in vitro

Objective Radix of Actinidiae chinensis,a medicinal plant used in China,is the dry root of Actini-diaceae plant and has been extensively employed to treat cancers of various organs,including the lung,liver and digestive system.However,up to now,its active antitumor and antiviral fractions remain unclear.The main purpose of this study is to identify the antitumor and antiviral sites of Radix of Actinidiae chinensis,which provides evidences for its further development.Methods Radix of Actinidiae chinensis was extracted by the refluxing sequentially with acetidin,ethanol and water,followed by the column chromatography and thin layer chromatography.The antitumor effects on Bel-7402,SW-620 and MDA-MB-231 tumor cells were investigated to screen the active antitumor sites by cell inhibition,the growth curve and the apoptosis staining.Meanwhile,to screen the active anti-hepatovirus fractions,the cell growth and the secretion of HBsAg and HBeAg in HepG2.2.15 cells were evaluated by the MTT test and enzyme-linked immunosorbent assay respectively.Results The acetidin fraction Y(Y1+Y2),the ethanol fraction A(A1+A3+A4) and B(A1+A4+A6),and the fraction compound C(A1+A4+Y1) have strong inhibitive effects on Bel-7402,SW-620 and MDA-MB-231 tumor cell lines.Moreover,the tumor cell apoptosis could be induced by the ethanol fraction B and the fraction compound C.In HepG2.2.15 cells,the treatment indexes of the acetidin fraction Y,the ethanol fraction A and the fraction compound C all exceeded 2 on the secretion of HBsAg,indicating the suppre-ssive effects of them on hepatitis B virus.The fraction yields of A,B and C exceeded 50%(60.28%,54.35% and 62.64% respectively),while that of Y did not(17.7%).Conclusion The ethanol fraction B and the fraction compound C are the antitumor sites of Actinidiae chinensis Radix,while the ethanol fraction A and the fraction compound C are its antiviral sites.

Experimental Study on the Dependency of Ice Nucleation Active Surface Site Density on ATD Aerosol Size

In light of the percentage of Earth’s cloud coverage, heterogeneous ice nucleation in clouds is the most important global-scale pathway. More recent parameterizations of ice nucleation processes in the atmosphere are based on the concept of ice nucleation active surface site density (ns). It is usually assumed that ns is independent of time and aerosol size distribution, i.e. that the surface properties of aerosols of the same species do not vary with size. However, the independence of ns on aerosol size for every species has been questioned. This study presents the results of ice nucleation processes of ATD laboratory-generated aerosol (particle diameters of 0 - 3 μm). Ice nucleation in the condensation mode was performed in a Dynamic Filter Processing Cham- ber at temperatures of -18°C and -22°C, with a saturation ratio with respect to water of 1.02. Results show that ns increased by lowering the nucleation temperature, and was also dependent on the particle size. The ns of particles collected on the filters, after a 0.5 μm D50 cut-off cyclone, resulted statistically higher with respect to the values obtained from the particles collected on total filters. The results obtained suggest the need for further investigation of ns dependence of same composition aerosol particles with a view to support weather and climate predictions.

Tropical forest canopies and their relationships with climate and disturbance： results from a global dataset of consistent field-based measurements

Background： Canopy structure, defined by leaf area index （LAI）, fractional vegetation cover （FCover） and fraction of absorbed photosynthetically active radiation （fAPAR）, regulates a wide range of forest functions and ecosystem services. Spatially consistent field-measurements of canopy structure are however lacking, particularly for the tropics. Methods： Here, we introduce the Global LAI database： a global dataset of field-based canopy structure measurements spanning tropical forests in four continents （Africa, Asia, Australia and the Americas）. We use these measurements to test for climate dependencies within and across continents, and to test for the potential of anthropogenic disturbance and forest protection to modulate those dependences. Results： Using data collected from 887 tropical forest plots, we show that maximum water deficit, defined across the most arid months of the year, is an important predictor of canopy structure, with all three canopy attributes declining significantly with increasing water deficit. Canopy attributes also increase with minimum temperature, and with the protection of forests according to both active （within protected areas） and passive measures （through topography）. Once protection and continent effects are accounted for, other anthropogenic measures （e.g. human population） do not improve the model. Conclusions： We conclude that canopy structure in the tropics is primarily a consequence of forest adaptation to the maximum water deficits historically experienced within a given region. Climate change, and in particular changes in drought regimes may thus affect forest structure and function, but forest protection may offer some resilience against this effect.

Therapeutic Activity of Partially Purified Fractions of Emblica officinalis （Syn, Phyllanthus embfica） Dried Fruits against Trypanosoma evansi

Emblica officinalis （E. oJficinalis） dried fruits were evaluated for its antitrypanosomal activity and cytotoxic effects. Vero cell line maintained in DMEM （Dubecco＇s Modified Eagle Medium） and incubated with Trypanosoma evansi for more than 12 h. MPE was added to the Vero cell culture medium at different concentrations （250-1,000 μg/mL） with trypanosomes concentration （1 × 106 trypanosomes/mL in each ELISA plate well） and incubated at appropriate conditions for 72 h. In-vitro cytotoxieity of MPE of E. officinalis was determined on Vero cells at concentrations （（1.56-100 ~tg/mL）. Acute toxicity and in-vivo infectivity tests were done in mice. Obtained MPE ofE. officinalis underwent process of purification via column chromatography, preparative chromatography and HPLC （higher performance liquid chromatography） with bioassay at different strata on Alsever＇s medium. In-vivo assay for trypanocidal activity, MPE and PPFs （partially purified fractions） of E. officinalis with two sets of mice, each mouse was inoculated with 1 × 104/mL oftrypanosomes and treated （48 h post inoculation） at concentrations （12.5, 25, 50, 100 and 200 mg/kg body weight） were administered at dose rate of 100 [tL per mouse via intraperitoneal route （in treating parassitemic mice） to different groups of mice, 6 mice per concentration. HPLC of partially purified fractions ofE. officinalis was carried out with mobile phase ofacetonitdle： water （40：60） in gradient mode. In vitro, MPE induced immobilization and killing of the parasites in concentration-time dependent manner. Significant reduction of trypanosomes counts from concentration of 250μg/mL and complete killing of trypanosomes at 5th hour of observation, which was statistically equivalent to 4th hour of Diminazine Aceturate （Berenil）, standard reference drug used. HPLC of the partially purified fractions revealed two major prominent peaks at retention time of 1-4 min. In vivo, both MPE and PPFs of test material did prolong lives of mice by 6-9 days but could not cure them. At concentration of 2,000 kg/kg body weight of MPE in acute test, all mice survived. For in-vivo infectivity test, mice injected with immobilized trypanosomes developed parasitemia and died while, the other group survived. MPE, PPFs and Diminazine Aceturate were toxic to Vero cells at all concentrations exception of 1.56, 1.56-3.13 and 1.56-6.25 μg/mL, respectively. From this report, PPFs ofE. officinalis dried fruits demonstrated potential pathway for a new development oftrypanocide in near future if additional investigations are put in place.

Antihyperglycemic, insulinsensitizing and antioxidant activities of the active fractions from Anoectochilus chapaensis

Anoectochilus chapaensis Gagnep. （Orchidaceae）, an indigenous and valuable Chinese folk medicine, has been widely used in China to treat diabetes. However, few reports are available about its constituents and activity. The present experiment was conducted to investigate the active fractions from A. chapaensis in diabetic rat model induced by high-fat diet plus streptozotocin. The total EtOH extract from the whole herbs ofA. chapaensis, half of which was partitioned in sequence with petrol ether （PE）, ethyl acetate （EtOAc）, n-BuOH and H2O, thus yielding four fractions, all of them were orally administered with an identical dose amount to 4 g/kg dried crude herbs once a day for consecutive two weeks to further investigate the antihyperglycemic activity. The EtOAc fraction caused a significant fall in the non-fasting blood glucose level of diabetic rats from （402.66±82.26） to （226.26±62.10） mg/dl, which may be attributed to ameliorating insulin resistance, modulating the activity of enzymatic antioxidants, reducing the content of NO, etc. Much more intact β cells in the islets of Langerhans in EtOAc fraction-treated groups than the negative control were observed, which greatly supported the morphological and functional elucidation. The OGTT evidenced that EtOAc fraction could promote the endurance capacity of acute glucose increase in diabetic rats. The EtOAc fraction of A. chapaensis contains some hypoglycemic and antioxidant principles with the potential to be developed further for the treatment of diabetes specifically associated with an insulin resistance state.

Toxicity comparison of different active fractions extracted from radix Sophorae tonkinensis in zebrafish

Radix Sophorae tonkinensis(RST) is a widely used herb in Traditional Chinese Medicine(TCM) for treating infectious and inflammatory diseases. However, the toxicity data for RST are limited. The aim of this work is to assess and compare the toxicity of the whole RST extract and its five active fractions using the zebrafish model. Five active fractions of RST were prepared using five different types of solvents, which included dealkalized water, ethanol, n-butyl ethanol, dichloromethane, and diethyl ether. The chemical profiles of the active fractions were determined by high-performance liquid chromatography(HPLC), and the toxicity observed in the zebrafish model was confirmed using mouse models. In the zebrafish model, cardiovascular toxicity was observed for the fraction extracted using diethyl ether, and hepatotoxicity was observed for the whole RST extract and the fractions extracted using water and ethanol, whereas both cardiovascular and hepatic toxicities were observed for the fractions extracted using n-butyl ethanol and dichloromethane. The hepatotoxicity of the fractions extracted using n-butyl ethanol and dichloromethane was also observed in mice. Our findings provide the toxicity data for RST and its five active fractions through modeling in a zebrafish, and indicate that the different fractions may each have a different toxicity, which is helpful for the optimal use of RST in clinical practice.

Remote estimation of the fraction of absorbed photosynthetically active radiation for a maize canopy in Northeast China

Aims accurate remote estimation of the fraction of absorbed photosynthetically active radiation(fAPAR)is essential for the light use efficiency(LUE)models.Currently,one challenge for the LUE models is lack of knowledge about the relationship between fAPAR and the normalized difference vegetation index(NDVI).Few studies have tested this relationship against field measurements and evaluated the accuracy of the remote estimation method.this study aimed to reveal the empirical relationship between NDVI and fAPAR and to improve algorithms for remote estimation of fAPAR.Methods to investigate the method of remote estimation of fAPAR seasonal dynamics,the CASA(Carnegie-ames-stanford approach)model and spectral vegetation indices(VIs)were used for in situ measure-ments of spectral reflectance and fAPAR during the growing season of a maize canopy in Northeast China.Important Findingsthe results showed that the fAPAR increased rapidly with the day of year during the vegetative stage,it remained relatively stable at the stage of reproduction,and finally decreased slowly during the senescence stage.In addition,fAPAR green[fAPAR_(green)=fAPAR_(green) -fAPAR_(green) LAI_(max))]showed clearer seasonal trends than fAPAR.the NDVI,red-edge NDVI,wide dynamic range vegetation index,red-edge position(REP)and REP with sentinel-2 bands derived from hyperspectral remote sensing data were all significantly positively related to fAPAR green during the entire growing season.In a comparison of the predictive performance of VIs for the whole growing season,REP was the most appropriate spectral index,and can be recommended for monitoring seasonal dynamics of fAPAR in a maize canopy.

Chemical profile of the active fraction of Yi-Gan San by HPLC–DAD–Q-TOF–MS and its neuroprotective effect against glutamate-induced cytotoxicity

Yi-Gan San(YGS), a traditional Chinese medicine for dementia-related symptoms, was previously fractionated. One active fraction, YGS40 exhibited a neuroprotective effect against glutamate-induced cytotoxicity. In the present study, high-performance liquid chromatography, coupled with diode-array detection and quadrupole time-of-flight mass spectrometry, was applied for the identification of its chemical constituents and for quantification studies. The chemical profile of YGS40 consisted of sixty-four identified or tentatively characterized compounds. The levels of the major marker compounds increased significantly in the mixed decoction compared with those in the single plant decoction. The results suggest the high precision of the analyses of most of the constituents in YGS40 and establish the quantitative variations of the major marker compounds between the single and mixed decoction processes.

Distribution of Soil Organic Carbon Fractions Along the Altitudinal Gradient in Changbai Mountain,China

Understanding the responses of soil organic carbon(SOC) fractions to altitudinal gradient variation is important for understanding changes in the carbon balance of forest ecosystems.In our study the SOC and its fractions of readily oxidizable carbon(ROC),water-soluble carbon(WSC) and microbial biomass carbon(MBC) in the soil organic and mineral horizons were investigated for four typical forest types,including mixed coniferous broad-leaved forest(MCB),dark coniferous spruce-fir forest(DCSF),dark coniferous spruce forest(DCS),and Ermans birch forest(EB),along an altitudinal gradient in the Changbai Mountain Nature Reserve in Northeast China.The results showed that there was no obvious altitudinal pattern in the SOC.Similar variation trends of SOC with altitude were observed between the organic and mineral horizons.Significant differences in the contents of SOC,WSC,MBC and ROC were found among the four forest types and between horizons.The contents of ROC in the mineral horizon,WSC in the organic horizon and MBC in both horizons in the MCB and EB forests were significantly greater than those in either DCSF or DCS forest.The proportion of soil WSC to SOC was the lowest among the three main fractions.The contents of WSC,MBC and ROC were significantly correlated(P < 0.05) with SOC content.It can be concluded that vegetation types and climate were crucial factors in regulating the distribution of soil organic carbon fractions in Changbai Mountain.

Study on Therapeutic Mechanism of Anti-Rheumatism Effect of Siegesbeckia Pubescens

Objective:To explore the mechanism of anti-rheumatic effect of the active fraction of Siegesbeckia pubescens(AFSP).Methods:Adjuvant arthritis(AA)model of rat was produced to observe the effect of AFSP on lymphocyte proliferation,interleukin-1 and-2(IL-1,-2)activity,pathologic section of ankle joint,and analgesic effect,in model rat.Results:AFSP could reduce the inflammatory pathologic response of ankle joint.It has good analgesic effect,the analgesic rate being 65%.AFSP could also strengthen T-lymphocyte proliferation,promote IL-2 activity and inhibit IL-1 activity.Compared with the control group,the difference was significant(P<0.01).Conclusion:By means of regulating the immune function of organism,AFSP could improve the local pathologic response to antagonize against rheumatism,therefore,it is an effective anti-rheumatism herbal medicine.