Development and verification of plaque method for detection of tick-borne encephalitis virus titer / 中国生物制品学杂志

@#Objective To develop and verify a plaque method for detection of infectious titer of tick-borne encephalitis virus(TBEV)strain(PHKT strain for short)adapted to primary hamster kidney(PHK)cells.Methods PHK cells were infected with TBEV,a primary mouse brain adaption strain,and passed consecutively for 12 passages.The titer of PHKT was detected by plaque method(Monolayer BHK-21 cells were infected with PHKT of various passages at different dilution ratios,and the plaque number was calculated by neutral red staining)and challenge titration in mouse brain(Mice were challenged with PHKT of various passages at different dilution ratios through brain cavity,0.03 mL for each,observed continuously for 14 days,and calculated for the median lethal dose(LD50)by Reed-Muench method)respectively,and the correlation between the results of two methods was analyzed.The developed plaque method for the detection of TBEV titer was verified for specificity,repeatability and intermediate precision.Results The plaque titer of PHKT virus was up to8.9 lgPFU/mL;The correlation between the results of plaque method and mouse brain challenge titration method was good(r = 0.92);The specificity of plaque method for detecting infectious titer of PHKT virus was good,and the coefficients of variation(CVs)of repeatability and intermediate precision were both less than 5%.Conclusion A plaque method for detecting infectious titer of PHKT virus was developed,which may be used as an alternative method for challenge titration in mouse brain.

Trilobatin rescues cognitive impairment of Alzheimer's disease by targeting HMGB1 through mediating SIRT3/SOD2 signaling pathway.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with cognitive impairment that currently is uncurable. Previous study shows that trilobatin (TLB), a naturally occurring food additive, exerts neuroprotective effect in experimental models of AD. In the present study we investigated the molecular mechanisms underlying the beneficial effect of TLB on experimental models of AD in vivo and in vitro. APP/PS1 transgenic mice were administered TLB (4, 8 mg· kg-1 ·d-1, i.g.) for 3 months; rats were subjected to ICV injection of Aß25-35, followed by administration of TLB (2.5, 5, 10 mg· kg-1 ·d-1, i.g.) for 14 days. We showed that TLB administration significantly and dose-dependently ameliorated the cognitive deficits in the two AD animal models, assessed in open field test, novel object recognition test, Y-maze test and Morris water maze test. Furthermore, TLB administration dose-dependently inhibited microglia and astrocyte activation in the hippocampus of APP/PS1 transgenic mice accompanied by decreased expression of high-mobility group box 1 (HMGB1), TLR4 and NF-κB. In Aß25-25-treated BV2 cells, TLB (12.5-50 µM) concentration-dependently increased the cell viability through inhibiting HMGB1/TLR4/NF-κB signaling pathway. HMGB1 overexpression abrogated the beneficial effects of TLB on BV2 cells after Aß25-35 insults. Molecular docking and surface plasmon resonance assay revealed that TLB directly bound to HMGB1 with a KD value of 8.541×10-4 M. Furthermore, we demonstrated that TLB inhibited Aß25-35-induced acetylation of HMGB1 through activating SIRT3/SOD2 signaling pathway, thereby restoring redox homeostasis and suppressing neuroinflammation. These results, for the first time, unravel a new property of TLB: rescuing cognitive impairment of AD via targeting HMGB1 and activating SIRT3/SOD2 signaling pathway.

[Effects of SIRT1 in amygdala on chronic restraint stress-induced depression-like behaviors in rats].

OBJECTIVE: To investigate the effects of silent information regulator 1 (SIRT1) in amygdala on depression-like behaviors in rats using chronic restraint stress (CRS) as a model of depression. METHODS: Sixty male SD rats were randomly divided into six groups (n=10 per group): control group (Control), chronic restraint stress group (CRS), CRS + fluoxetine-treated group (CRS + FLU), CRS + saline-treated group (CRS + NaCl), CRS + SIRT1-overexpression group (CRS + AAV-SIRT1), and CRS + empty vector group (CRS + AAV-EGFP). Except for the control group, rats from the other groups were exposed to chronic restraint stress for 21 days. After the modeling, rats in fluoxetine-treated group and saline-treated group were, respectively, treated with fluoxetine (10 mg/kg) or saline (10 mg/kg) by gavage every day for 3 weeks; AAV-SIRT1 or AAV-EGFP was, respectively, stereotaxically injected into the amygdala of rats in SIRT1-overexpression group and empty vector group, and the virus was expressed for 3 weeks. Rats in normal control group and CRS model group were not given any drug treatment. The depression-like behaviors of rats in each group were evaluated by sugar preference test (SPT), open field test (OFT) and forced swimming test (FST). SIRT1 expression in amygdala of rats was assessed by using immunoblot blotting. The number of SIRT1-positive cells in amygdala of rats was detected by immunofluorescence technique. RESULTS: Compared with the normal control group, the level of SIRT1 protein and the number of SIRT1+ cells in amygdala of the CRS-exposed rats were decreased significantly (P＜0.01), and CRS-exposed rats showed a significant decrease in sucrose preference (P＜0.01), less total horizontal distance (P＜0.01) and less time entered the center field (P＜0.01) in the OFT, a significant increase in the immobility time of the FST (P＜0.01). Fluoxetine treatment (P＜0.05, P＜0.01) or SIRT1 overexpression (P＜0.01) partially reversed the down-regulation of SIRT1 protein and SIRT1+ cells in amygdala of CRS-exposed rats and significantly improved the depression-like behaviors of CRS rats. CONCLUSION: Fluoxetine treatment partially reversed the down-regulation of SIRT1 level and the number of SIRT1+ in CRS rats, and significantly improved the depression-like behaviors. The antidepressant effect of fluoxetine treatment may be related to the up-regulation of SIRT1 in the amygdala of CRS-exposed rats.

Comparison of the effects of nicotinic acid and nicotinamide degradation on plasma betaine and choline levels.

AIM: The present study was to compare the effects of nicotinic acid and nicotinamide on the plasma methyl donors, choline and betaine. METHODS: Thirty adult subjects were randomly divided into three groups of equal size, and orally received purified water (C group), nicotinic acid (300 mg, NA group) or nicotinamide (300 mg, NM group). Plasma nicotinamide, N1-methylnicotinamide, homocysteine, betaine and choline levels before and 1.5-h and 3-h post-dosing, plasma normetanephrine and metanephrine concentrations at 3-h post-dosing, and the urinary excretion of N1-methyl-2-pyridone-5-carboxamide during the test period were examined. RESULTS: The level of 3-h plasma nicotinamide, N1-methylnicotinamide, homocysteine, the urinary excretion of N1-methyl-2-pyridone-5-carboxamide and pulse pressure (PP) in the NM group was 221%, 3972%, 61%, 1728% and 21.2% higher than that of the control group (P < 0.01, except homocysteine and PP P < 0.05), while the 3-h plasma betaine, normetanephrine and metanephrine level in the NM group was 24.4%, 9.4% and 11.7% lower (P < 0.05, except betaine P < 0.01), without significant difference in choline levels. Similar but less pronounced changes were observed in the NA group, with a lower level of 3-h plasma N1-methylnicotinamide (1.90 ± 0.20 µmol/l vs. 3.62 ± 0.27 µmol/l, P < 0.01) and homocysteine (12.85 ± 1.39 µmol/l vs. 18.08 ± 1.02 µmol/l, P < 0.05) but a higher level of betaine (27.44 ± 0.71 µmol/l vs. 23.52 ± 0.61 µmol/l, P < 0.05) than that of the NM group. CONCLUSION: The degradation of nicotinamide consumes more betaine than that of nicotinic acid at identical doses. This difference should be taken into consideration in niacin fortification.

Preeclampsia and future cardiovascular risk: A point of view from the clearance of plasma vasoactive amines.

OBJECTIVE: To summarize the reported evidence on the relationship between vasoactive amines and preeclampsia. METHODS: A literature search was conducted in MEDLINE/PubMed and EMBASE. RESULTS: The summarized results are as follows: (1) Menstruation can effectively eliminate vasoactive amines norepinephrine, serotonin and histamine. (2) Pregnancy increases norepinephrine production due to fetal brain development and decreases vasoactive-amine elimination due to amenorrhea. (3) Preeclampsia is associated with a low renal and/or sweating capacity, or in rare cases, with increased norepinephrine production due to maternal pheochromocytoma and fetal neuroblastoma. CONCLUSION: Preeclampsia is mainly due to decreased excretion of norepinephrine and other vasoactive amines.

Vitamin paradox in obesity: Deficiency or excess?

Since synthetic vitamins were used to fortify food and as supplements in the late 1930s, vitamin intake has significantly increased. This has been accompanied by an increased prevalence of obesity, a condition associated with diabetes, hypertension, cardiovascular disease, asthma and cancer. Paradoxically, obesity is often associated with low levels of fasting serum vitamins, such as folate and vitamin D. Recent studies on folic acid fortification have revealed another paradoxical phenomenon: obesity exhibits low fasting serum but high erythrocyte folate concentrations, with high levels of serum folate oxidation products. High erythrocyte folate status is known to reflect long-term excess folic acid intake, while increased folate oxidation products suggest an increased folate degradation because obesity shows an increased activity of cytochrome P450 2E1, a monooxygenase enzyme that can use folic acid as a substrate. There is also evidence that obesity increases niacin degradation, manifested by increased activity/expression of niacin-degrading enzymes and high levels of niacin metabolites. Moreover, obesity most commonly occurs in those with a low excretory reserve capacity (e.g., due to low birth weight/preterm birth) and/or a low sweat gland activity (black race and physical inactivity). These lines of evidence raise the possibility that low fasting serum vitamin status in obesity may be a compensatory response to chronic excess vitamin intake, rather than vitamin deficiency, and that obesity could be one of the manifestations of chronic vitamin poisoning. In this article, we discuss vitamin paradox in obesity from the perspective of vitamin homeostasis.

A novel crosstalk between BRCA1 and poly (ADP-ribose) polymerase 1 in breast cancer.

BRCA mutations are the main known hereditary factor for breast cancer. Notably, poly (ADP-ribose) polymerase 1 (PARP1) expression status plays a critical role in breast cancer progression and the clinical development of PARP1 inhibitors to treat BRCA-mutated breast cancer has advanced rapidly. However, dynamic crosstalk between BRCA1 and PARP1 remains largely unknown. Here, we showed that: (i) BRCA1 inactivation events (mutation, promoter methylation, or knockdown) were accompanied by increased PARP1 and nicotinamide adenine dinucleotide (NAD) levels, and a subsequent increase in NAD-dependent PARP1 activity in MDA-MB-231 and primary breast cancer cells; (ii) the overexpression of BRCA1 resulted in decreased PARP1 and NAD levels, and a subsequent impairment in NAD-dependent PARP1 activity in MDA-MB-231 and primary breast cancer cells; and (iii) intracellular NAD levels were largely responsible for regulating PARP1 activity in breast cancer cells, and NAD levels were positively correlated with PARP1 activity in human breast cancer specimens (R = 0.647, P < 0.001). Interestingly, the high efficiency of PARP1 triggered by BRCA1 inactivation may further inhibit BRCA1 transcription by NAD depletion. These results highlight a novel interaction between BRCA1 and PARP1, which may be beneficial for the dynamic balance between BRCA1 and PARP1-related biologic processes, especially for maintaining stable DNA repair ability. All of this may improve our understanding of the basic molecular mechanism underlying BRCA1- and PARP1-related breast cancer progression.

BRCA1 as a nicotinamide adenine dinucleotide (NAD)-dependent metabolic switch in ovarian cancer.

Both hereditary factors (e.g., BRCA1) and nicotinamide adenine dinucleotide (NAD)-dependent metabolic pathways are implicated in the initiation and progression of ovarian cancer. However, whether crosstalk exists between BRCA1 and NAD metabolism remains largely unknown. Here, we showed that: (i) BRCA1 inactivation events (mutation and promoter methylation) were accompanied by elevated levels of NAD; (ii) the knockdown or overexpression of BRCA1 was an effective way to induce an increase or decrease of nicotinamide phosphoribosyltransferase (Nampt)-related NAD synthesis, respectively; and (iii) BRCA1 expression patterns were inversely correlated with NAD levels in human ovarian cancer specimens. In addition, it is worth noting that: (i) NAD incubation induced increased levels of BRCA1 in a concentration-dependent manner; (ii) Nampt knockdown-mediated reduction in NAD levels was effective at inhibiting BRCA1 expression; and (iii) the overexpression of Nampt led to higher NAD levels and a subsequent increase in BRCA1 levels in primary ovarian cancer cells and A2780, HO-8910 and ES2 ovarian cancer cell lines. These results highlight a novel link between BRCA1 and NAD. Our findings imply that genetic (e.g., BRCA1 inactivation) and NAD-dependent metabolic pathways are jointly involved in the malignant progression of ovarian cancer.

A novel crosstalk between BRCA1 and sirtuin 1 in ovarian cancer.

BRCA mutations are the main known hereditary factors for ovarian cancer. Notably, emerging evidence has led to considerable interest in the role of sirtuin 1 (SIRT1) in ovarian cancer development. However, dynamic crosstalk between BRCA1 and SIRT1 is poorly understood. Here, we showed that: (i) BRCA1 inactivation events (mutation, promoter methylation, or knockdown) were accompanied by decreased SIRT1 levels and increased nicotinamide adenine dinucleotide (NAD) levels and a subsequent increase in SIRT1 activity; (ii) overexpression of BRCA1 resulted in increased SIRT1 levels, an impairment in NAD synthesis, and a subsequent inhibition of SIRT1 activity; and (iii) intracellular NAD levels were largely responsible for regulating SIRT1 activity, and BRCA1 expression patterns correlated with SIRT1 levels and NAD levels correlated with SIRT1 activity in human ovarian cancer specimens. Interestingly, although BRCA1 inactivation events inhibited SIRT1 expression, they led to a substantial increase in NAD levels that enhanced NAD-related SIRT1 activity. This is a special BRCA1-mediated compensatory mechanism for the maintenance of SIRT1 function. Therefore, these results highlight a novel interaction between BRCA1 and SIRT1, which may be beneficial for the dynamic balance between BRCA1-related biologic processes and SIRT1-related energy metabolism and stress response.

An unusual piceatannol dimer from Rheum austral D. Don with antioxidant activity.

A novel dimer of piceatannol glycoside, named rheumaustralin (1) was isolated from the underground parts of the ethnomedicinal plant Rheum austral (Polygonaceae) collected from Tibet together with 17 known compounds, including rheumin (2), 2,5-dimethyl-7-hydroxychromone (3), 2,5-dimethylchromone-7-O-ß-D-glucopyranoside (4), 7-hydroxy-2-(2'-hydroxypropyl)-5-methylchromone (5), torachrysone (6) torachrysone-8-O-ß-D-glucopyranoside (7), 4-(4'-hydroxyphenyl)-2-butanone-4'-O-ß-D-glucopyranoside (8), amabiloside (9), N-trans-feruloyl tyramine (10), chrysophanol (11), aloe-emodin (12), emodin (13), physcion (14), physcion-1-O-ß-D-glucopyranoside (15), emodin-8-O-ß-D-glucopyranoside (16), D-catechin (17) and gallic acid (18). Their structures were determined by combined spectroscopic methods and by comparison of their spectral data with those reported in literature. Compounds 1-10 were tested for their ability to scavenge 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical.

Cyclovirobuxinum D suppresses lipopolysaccharide-induced inflammatory responses in murine macrophages in vitro by blocking JAK-STAT signaling pathway.

AIM: Cyclovirobuxinum D (CVB-D), an alkaloid isolated from the Chinese medicinal plant Buxus microphylla, has been found to be effective to treat cardiac insufficiency, arrhythmias and coronary heart disease. In the present study, we investigated the effects of CVB-D on the inflammatory responses in lipopolysaccharide (LPS)-stimulated murine macrophages in vitro and the underlying mechanisms. METHODS: Murine macrophage cell line RAW264.7 cells were incubated in the presence of LPS (0.1 µg/mL) for 24 h. The cell viability was measured using MTT assay. The release of NO and cytokines were detected using the Griess test and ELISA, respectively. The mRNA and protein levels were determined using RT-PCR and Western blot, respectively. Reporter gene assays were used to analyze the transcriptional activity of NF-κB. RESULTS: Treatment of RAW264.7 cells with CVB-D (25-300 µmol/L) did not affect the cell viability. Pretreatment with CVB-D (50, 100 and 200 µmol/L) concentration-dependently decreased NO release and iNOS expression in LPS-treated RAW264.7 cells (its IC50 value in inhibition of NO production was 144 µmol/L). CVB-D also concentration-dependently inhibited the secretion and mRNA expression of IL-1ß and IL-6 in LPS-treated RAW264.7 cells. Furthermore, CVB-D remarkably inhibited the phosphorylation of STAT1 and STAT3, as well as JAK2 in LPS-treated RAW264.7 cells, but did not affect the activation of NF-κB and MAPKs pathways. Pretreatment with the JAK2 specific inhibitor AG490 (30 µmol/L) produced similar effects on NO release and iNOS expression in LPS-treated RAW264.7 cells. CONCLUSION: CVB-D exerts anti-inflammatory effects in LPS-stimulated murine macrophages in vitro at least in part by blocking the JAK-STAT signaling pathway. The anti-inflammatory actions of CVB-D may contribute to its cardioprotection.

Epigenetic repression of phosphatidylethanolamine N-methyltransferase (PEMT) in BRCA1-mutated breast cancer.

Phosphatidylethanolamine N-methyltransferase (PEMT) plays a critical role in breast cancer progression. However, the epigenetic mechanism regulating PEMT transcription remains largely unknown. Here, we show that the first promoter-specific transcript 1 is the major PEMT mRNA species, and methylation of the -132 site is a key regulatory element for the PEMT gene in BRCA1-mutated breast cancer. Mechanistically, hypermethylated -132 site-mediated loss of active histone marks H3K9ac and increase of repressive histone marks H3K9me enrichment synergistically inhibited PEMT transcription. Clinicopathological data indicated that a hypermethylated -132 site was associated with histological grade (P = 0.031) and estrogen receptor status (P = 0.004); univariate survival and multivariate analyses demonstrated that lymph node metastasis was an independent and reliable prognostic factor for BRCA1-mutated breast cancer patients. Our findings imply that genetic (e.g., BRCA1 mutation) and epigenetic mechanisms (e.g., DNA methylation and histone modifications) are jointly involved in the malignant progression of PEMT-related breast cancer.

Maternal nicotinamide supplementation causes global DNA hypomethylation, uracil hypo-incorporation and gene expression changes in fetal rats.

Recent evidence shows that excess nicotinamide can cause epigenetic changes in developing rats. The aim of the present study was to investigate the effects of maternal nicotinamide supplementation on the fetus. Female rats were randomised into four groups fed a standard chow diet (control group) or diets supplemented with 1 g/kg of nicotinamide (low-dose group), 4 g/kg of nicotinamide (high-dose group) or 4 g/kg of nicotinamide plus 2 g/kg of betaine (betaine group) for 14-16 d before mating and throughout the study. Fetal tissue samples were collected on the 20th day of pregnancy. Compared with the control group, the high-dose group had a higher fetal death rate, and the average fetal body weight was higher in the low-dose group but lower in the high-dose group. Nicotinamide supplementation led to a decrease in placental and fetal hepatic genomic DNA methylation and genomic uracil contents (a factor modifying DNA for diversity) in the placenta and fetal liver and brain, which could be completely or partially prevented by betaine. Moreover, nicotinamide supplementation induced tissue-specific alterations in the mRNA expression of the genes encoding nicotinamide N-methyltransferase, DNA methyltransferase 1, catalase and tumour protein p53 in the placenta and fetal liver. High-dose nicotinamide supplementation increased fetal hepatic α-fetoprotein mRNA level, which was prevented by betaine supplementation. It is concluded that maternal nicotinamide supplementation can induce changes in fetal epigenetic modification and DNA base composition. The present study raises the concern that maternal nicotinamide supplementation may play a role in the development of epigenetic-related diseases in the offspring.

High-birefringence, low-loss porous fiber for single-mode terahertz-wave guidance.

A new kind of polymer porous fiber with elliptical air-holes is designed for obtaining high birefringence in the terahertz (THz) frequency range in this paper. Using the finite element method, the properties of this kind of fiber are simulated in detail including the single-mode propagation condition, the birefringence, and the loss. Theoretical results indicate that the single-mode THz wave in the frequency range from 0.73 to 1.22 THz can be guided in the fiber; the birefringence can be enhanced by rotating the major axis of the elliptical air-hole and there exists an optimal rotating angle at 30°. At this optimal angle a birefringence as high as 0.0445 can be obtained in a wide frequency range. Low-loss THz guidance can be achieved owing to the effective reduction of the material absorption in such a porous fiber. This research is useful for polarization-maintaining THz-wave guidance.

New resveratrol oligomer derivatives from the roots of Rheum lhasaense.

Two new resveratrol trimer derivatives, named rheumlhasol A (1) and rheumlhasol B (2) were isolated from the methanolic extract of roots of Rheum lhasaense A. J. Li et P. K. Hsiao together with four known resveratrol dimer derivatives, including maximol A (3), gnetin C (4), ε-viniferin (5), and pallidol (6). The structures were determined by combined spectroscopic methods and by comparison of their spectral data with those reported in the literature. All the compounds isolated from R. lhasaense were tested for their ability to scavenge1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.

[Study on the anti-endotoxin effect of saponin from Tupistra chinensis].

OBJECTIVE: To investigate the effect of saponin from Tupistra chinensis Baker (STCB) on lethal toxicity of endotoxin in mice and explore the underlying mechanism. METHODS: Mouse models of endotoxin-induced death and endotoximia were established by intraperitoneal administration of KM mice with lipopolysaccharides (LPS) from Pseudomonas aeruginosa in doses of 60 mg/kg and 10 mg/kg respectively. Mouse survival rate and survival time were recorded and the serum levels of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in endotoximia mice were measured by enzyme-linked immunosorbent assay (ELISA). Mouse peritoneal exudate cells induced by LPS were used as an in vitro inflammatory model,which was then intervened with STCB and the levels of IL-1beta and TNF-alpha in the culture supernatants were measured by ELISA. RESULTS: The survival rates of mice prophylactically treated with STCB (200 and 400 mg/kg, in 5 consecutive days) were slightly higher compared with that in model group,but no statistical difference was observed (P>0.05). The survival time was much longer in the treated group (P<0.05). The serum levels of IL-1beta and TNF-alpha in STCB-treated mice (200 and 400 mg/kg, in 5 consecutive days) were significantly lower compared with those in model group (P<0.05). STCB (20 and 40 microg/mL) remarkably inhibited LPS-induced IL-1beta and TNF-alpha production by peritoneal exudate cells in vitro (P<0.05). CONCLUSION: Saponin from Tupistra chinensis showed beneficial effect on the prevention of mice from lipopolysaccharides-induced death, in which down regulation of IL-1beta and TNF-alpha expression might be involved.

[Prostaglandin E2 promotes hepatocellular carcinoma cell proliferation through EP2 prostanoid receptor].

OBJECTIVE: To investigate the effect of prostaglandin E2 (PGE(2)) on the proliferation of cultured hepatocellular carcinoma cells and explore which subtypes of EP prostanoid receptor mediate the action. METHODS: RT-PCR was used to determine COX-2 and EP receptor mRNA expression levels in human hepatocellular carcinoma cell line Hep3B and human normal hepatocyte line QSG7701. Cell counting kit-8 (CCK-8) assay was employed to investigate the effect of PGE(2), selective EP2 receptor agonist butaprost and EP3/EP4 receptor agonist PGE1 alcohol on the proliferation of the cells. RESULTS: COX-2 mRNA was highly expressed in Hep3B cells but scarcely in QSG7701 cells. Hep3B cells expressed the mRNAs for all the EP receptor subtypes, but EP2 and EP4 receptors were much more strongly expressed than EP1 and EP3 receptors. PGE(2) significantly promoted Hep3B cell proliferation in a time- and dose-dependent manner, and 10 µmol/L PGE(2) increased the cell proliferation by 22.57% (P<0.001) after a 48-h incubation; treatment with 0.1, 1.0, and 10 µmol/L PGE(2) for 72 h resulted in significantly increased cell proliferation by 12.13% (P<0.01), 17.58% (P<0.01) and 33.07% (P<0.001), respectively. EP2 receptor agonist butaprost (20 µmol/L) increased Hep3B cell proliferation by 21.96% (P<0.001), but the EP3/EP4 receptor agonist PGE(1) alcohol (2-20 µmol/L) exhibited no significant mitogenic effect in Hep3B cells, and 200 µmol/L PGE(1) alcohol decreased the cell viability. CONCLUSION: Selective activation of EP2 receptor promotes Hep3B cell proliferation, indicating the predominant role of EP2 receptor in mediating the mitogenic effect of PGE2.

[Process optimization for extraction of immune active polysaccharides from Fomes fomentarius by introduction of ultrasonication].

OBJECTIVE: To study the optimal extraction process of immune active polysaccharides from Fomes fomentarius by introduction of ultrasonication. METHODS: An orthogonal experimental design of L9 (3(4)) was used to investigate the effects of ultrasonication time, extraction temperature and extraction time on the extraction ratio, sugar content and immune stimulating activity (mouse splenocyte metabolic activity measured with MTT colorimetry) of the polysaccharides and the optimal extraction process was evaluated. RESULTS: Ultrasonication treatment had the most remarkable effect on the immune stimulating activity of the polysaccharides. The optimal extraction process for extraction of immune active polysaccharides was as follows: ultrasonication for 30min, extraction temperature at 80 degrees C and water extraction time for 2h. CONCLUSION: Ultrasonication can be used as a useful technique for extraction of immune active polysaccharides from Fomes fomentarius.

[Suppressive effect of matrine on cell growth and decreases beta-catenin-dependent transcriptional activity in hepatoma cell line Hep3B].

OBJECTIVE: To investigate the effects of matrine on proliferation, cell cycle, apoptosis rate and beta-catenin-dependent transcriptional activity in cultured hepatoma cell line Hep3B. METHODS: Cell viability was analyzed by cell counting kit-8 (CCK-8) assay. Cell cycle and apoptosis rate wene determined by flow cytometry analysis, beta-catenin-dependent transcriptional activity was assayed with Dual-Luciferase Reporter System. RESULTS: 72 h of matrine (50 - 800 mg/L) exposure significantly suppresses Hep3B cells growth in a concentration-dependent manner (P<0.01), the 50 percent inhibitory concentration (IC50) was 312.53 mg/L. A higher proportion of apoptotic cells in matrine-treated group than in control groups (21.73 +/- 1.66% vs. 4.39 +/- 1.93%) are shown. Cell proportions in G0/G1 phase were respectively 74.48% and 57.39% in matrine-treated group and control group. Cell proportions in S phase wene respectively 12.94% and 27.67%. Beta-catenin reporter activity was also decreased by matrine treatment in a concentration-dependent manner in Hep3B cells (P<0.05 or P<0.01). CONCLUSION: Through inhibition of beta-catenin-dependent transcription, matrine induces cell cycle arrest and apoptosis, and subsequently suppresses proliferation of hepatoma cells.

[Effects of exogenous Ca2+ on morphological and photosynthetic characteristics and chlorophyll fluorescent parameters of squash seedlings under high temperature and strong light stress].

Taking squash (Cucurbita pepo L.) variety Alan as test object, this paper studied the effects of exogenous Ca2+ on the morphological and photosynthetic characteristics and chlorophyll fluorescent parameters of squash seedlings under the cross-stress of high temperature and strong light. Under the stress, applying 5-20 mmol x L(-1) of Ca2+ increased the plant height, leaf area, chlorophyll and carotenoid contents, photosynthetic rate (Pn), stoma conductance (Gs), transpiration rate (Tr), maximal PS II efficiency (Fv/Fm), actual PS II efficiency (phi(PS II)), and photochemical queching coefficient (q(P)), and decreased the intercellular CO2 concentration (Ci) and non-photochemical fluorescence quenching coefficient (NPQ), suggesting that this application of exogenous Ca2+ could effectively mitigate the damage of high temperature and strong light stress on the squash seedlings leaf, and make it keep more rapid photosynthetic electron transfer rate and higher PS II electron transfer activity. Among the treatments of applying Ca2+, 10 mmol Ca2+ x L(-1) had the best effect. When the Ca2+ application rate exceeded 40 mmol x L(1), no mitigation effect was observed on the high temperature and strong light stress.