[Application of high performance liquid-ion trap mass spectrometry in analyzing saponins in sodium aescinate].

Sodium aescinate, which is produced from saponins of Chinese Buckeye Seed, is a prescription drug for treatment of brain edema and all kinds of swellings caused by surgery. In this article, high-performance liquid chromatography/ion trap (HPLC-IT) mass spectrometry was applied to study the characteristic ions of ten reference substances, namely escin Ⅰa, escin Ⅰb, isoescin Ⅰa, isoescin Ⅰb, aesculiside A, aesculiside B, aesculuside A, escin Ⅳc, escinⅡa and escin Ⅴ, which were isolated from aescinate. Furthermore, 19 saponin compounds were predicted in sodium aescinate, besides the above mentioned reference substances. The study showed that sapogenins in sodium aescinate had two structural types, namely protoaescigenin and barringenol C, and the substituent acetyl, tigloyl or angeloyl was usually located at C-21, C-22 or C-28 position. Among these predicted saponins, their sugar chains were all located at C-3 position consisting of glucose and glucuronide. This study provides experimental data for chemical constituents in sodium aescinate and scientific basis for quality and safety evaluation.

Muscle-specific calpastatin overexpression prevents diaphragm weakness in cecal ligation puncture-induced sepsis.

Recent work indicates that infections are a major contributor to diaphragm weakness in patients who are critically ill and mechanically ventilated, and that diaphragm weakness is a risk factor for death and prolonged mechanical ventilation. Infections activate muscle calpain, but many believe this is an epiphenomenon and that other proteolytic processes are responsible for infection-induced muscle weakness. We tested the hypothesis that muscle-specific overexpression of calpastatin (CalpOX; an endogenous calpain inhibitor) would attenuate diaphragm dysfunction in cecal ligation puncture (CLP)-induced sepsis. We studied 1) wild-type (WT) sham-operated mice, 2) WT CLP-operated mice, 3) CalpOX sham-operated mice, and 4) CalpOX CLP-operated mice (n = 9-10/group). Twenty-four hours after surgery, we assessed the diaphragm force-frequency relationship, diaphragm mass, and total protein content and diaphragm levels of talin and myosin heavy chain (MHC). CLP markedly reduced diaphragm-specific force generation (force/cross-sectional area), which was prevented by calpastatin overexpression (force averaged 21.4 ± 0.5, 6.9 ± 0.8, 22.4 ± 1.0, and 18.3 ± 1.3 N/cm(2), respectively, for WT sham, WT CLP, CalpOX sham, and CalpOX CLP groups, P < 0.001). Diaphragm mass and total protein content were similar in all groups. CLP induced talin cleavage and reduced MHC levels; CalpOX prevented these alterations. CLP-induced sepsis rapidly reduces diaphragm-specific force generation and is associated with cleavage and/or depletion of key muscle proteins (talin, MHC), effects prevented by muscle-specific calpastatin overexpression. These data indicate that calpain activation is a major cause of diaphragm weakness in response to CLP-induced sepsis.

Inhibitory effects of cocoa tea (Camellia ptilophylla) in human hepatocellular carcinoma HepG2 in vitro and in vivo through apoptosis.

Cocoa tea (Camellia ptilophylla), a naturally decaffeinated tea commonly consumed as a healthy beverage in southern China, has been recently found to be a potential candidate for the treatment of different diseases, including obesity and cancers. The present study aimed to evaluate the anti-liver cancer activities of green cocoa tea infusion (GCTI) in vitro and in vivo using human hepatocarcinoma cell line HepG2 cells and nude mice xenograft model. The apoptotic activities of GCTI were assessed using flow cytometry, Western blotting and immunohistochemical analysis. Our results showed that GCTI significantly inhibited the proliferation of HepG2 cells in a dose-dependent manner (IC50 values=292 µg/ml at 72 h). GCTI induced HepG2 cells to undergo apoptosis, which was demonstrated by cell cycle analysis and annexin-V and propidium iodide staining. The caspase cascade was activated as shown by significant proteolytic cleavage of caspase-3 and PARP in GCTI-treated cells in a dose- and time-dependent manner. In addition, GCTI increased the expression of cell cycle inhibitory proteins (p21, p27 and p53) and the Bax-to-Bcl-2 ratio to induce apoptosis. The antiproliferative effect of GCTI was confirmed in HepG2 xenograft nude mice. The tumor growth was effectively inhibited by GCTI in a dose-dependent manner as indicated by the decrease in tumor volume and tumor weight after 4 weeks of treatment. Administration of GCTI increased terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and caspase-3-positive cells in the tumor section. In conclusion, these results revealed that GCTI may be a potential and promising agent of natural resource to treat liver cancer.

Effects of modified Haizao Yuhu Decoction in experimental autoimmune thyroiditis rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Modified Haizao Yuhu Decoction (MHYD), based on clinical experience, has been used for approximately 500 years and famous for its efficiency in treating thyroid-related diseases. AIM OF THE STUDY: To investigate therapeutic effects of MHYD on thyroid-related autoantibodies and thyroid hormone in experimental autoimmune thyroiditis (EAT) rats, and to provide evidence for the immunomodulatory potential during antigenmediated immunostimulation. MATERIALS AND METHODS: The effect of MHYD was investigated in EAT rats induced by subcutaneous injection of porcine thyroglobulin with Freund's adjuvant (complete and incomplete, CFA and IFA). MHYD was fed to EAT rats daily at a dose of 100mg/kg for 10 weeks. The presence of mononuclear cell infiltration in thyroid tissues were examined to assess the severity of EAT. The levels of serum T3, T4, TgAb and TPOAb were determined by radioimmunoassay and protein expressions of TRAIL were detected by immunohistochemistry. RESULTS: MHYD exhibited a significant protective effects by reversing serum T3, T4, TgAb and TPOAb levels, histopathological changes and TRAIL protein expression of thyroid in EAT model rats. Sargassum fusiforme and Radix Glycyrrhiza in the formulation could be responsible for the immunomodulatory effects of MHYD. CONCLUSIONS: These results showed MHYD playing a role as an immunomodulator and TRAIL inhibitor during antigenmediated immunostimulation, may warrant further evaluation as a possible agent for the treatment of Hashimoto's thyroiditis.

[Proteasome inhibitors sensitize ovarian cancer cells to cisplatin].

OBJECTIVE: To explore the sensitivity and the molecular mechanism of cisplatin-resistance ovarian cancer cell line C13 to proteasome inhibitors and the combination with cisplatin. METHODS: After different treatments, methyl thiazolyl tetrazolium (MTT) assay was applied to examine the cell viability, annexin-V/propidium iodide (PI) apoptosis detection kit was used to determine the apoptosis rate of different groups, western blot assay was introduced to evaluate the expression levels of Fas-associated death domain-like interleukin-1 beta converting enzyme inhibitory protein (cFLIPs), and the activity of caspase-8 was examined. RESULTS: MTT assay shown that the cell viability ratios of combination group at serial time points from 12, 24, 36, 48, 60, 72 hours were (56.0 ± 8.4) %, (44.7 ± 7.3) %, (33.7 ± 11.2) %, (27.6 ± 8.0) %, (27.6 ± 7.6) % and (28.1 ± 2.4) %, which were much lower than those of cisplatin group (P < 0.05). After treated for 24 hours, apoptosis rates of cisplatin group, bortezomib group and combination group were (16.7 ± 1.7) %, (23.4 ± 2.1) % and (26.9 ± 1.6) %, respectively. The rate of combination group was much higher than that of non-treated group and that of cisplatin group or bortezomib group (P < 0.05). Western blot assay showed the changes of expression levels of cFLIPs, which were down-regulated seriously after cisplatin, bortezomib or combination treatment [(43.2 ± 2.3) % vs (75.7 ± 3.0) % vs (67.9 ± 2.1) %, P < 0.05]. The caspase-8 activity of combination group was (5.6 ± 1.6) folds than that of non-treated group, which was higher than those of other two groups [(2.3 ± 1.0) and (4.2 ± 0.9) folds, P < 0.05]. CONCLUSIONS: The tumor cell lethal effect of cisplatin could be increase significantly by the combination application of proteasome inhibitors, bortezomib. And the cFLIPs/caspase-8 signaling pathway may be play an important role in the molecular mechanism of the combination treatment.

The metabolites of mangrove endophytic fungus Zh6-B1 from the South China Sea.

Two new metabolites, 3R,5R-Sonnerlactone (1) and 3R,5S-Sonnerlactone (2), were isolated from the mangrove endophytic fungus Zh6-B1 obtained from the South China Sea. Their structures were elucidated by MS and NMR. The absolute configuration of compound 1 was determined by single-crystal X-ray analysis using Cu Kalpha radiation. The absolute configuration of compound 2 was determined by NOESY analysis and comparing circular dichroism spectroscopy with compound 1. The antiproliferative activity of compound 1 and 2 against the multi-drug resistant human oral floor carcinoma cells (KV) was evaluated.

[Effects of different glucocorticoids on blood glucose during surgery under general anesthesia].

OBJECTIVE: To evaluate the effects of different glucocorticoids upon blood glucose during surgery under general anesthesia. METHODS: Thirty (ASA I/II) patients scheduled for surgery under combined intravenous-inhalational anesthesia were randomly divided into 3 groups: dexamethasone group (Group D), methylprednisolone group (Group M) and normal saline group (Group S). Patients received dexamethasone, 10 mg IV (Group D), or methylprednisolone, 120 mg IV (Group M), or normal saline, 10 ml IV (Group S) at pre-induction. Arterial blood was collected preoperatively, and at 60, 120, 180 min post-injection to analyze the blood glucose. RESULTS: As compared to baseline, blood glucose increased significantly in Group D at 60, 120, 180 min post-injection (P < 0.01). In Group M, blood glucose increased significantly at 180 min post-injection (P < 0.01). In Group S, blood glucose increased significantly at 60, 120, 180 min post-injection respectively (P < 0.01). Comparison among these three groups indicated that differences between Group D and Group M (P = 0.01) or Group S (P < 0.05) were significant at 120 min post-injection. The difference between Group D and Group M was significant at 180 min post-injection (P < 0.05). CONCLUSION: The blood glucose often increases significantly during surgery under general anesthesia. Use of glucocorticoids may aggravate hyperglycemia, so that close monitoring and control are quite important. Methylprednisolone has less effect upon blood glucose than dexamethasone.

Inhibition of cytochrome P450 enzymes by rhein in rat liver microsomes.

Rhein, an active ingredient extensively found in plants such as Aloe, Cassitora L., rhubarb and so on, has been used for a long time in China. Pharmacological tests revealed that rhein not only had a strong antibacterial action, but also may be useful in cancer chemotherapy as a biochemical modulator. Its therapeutic action and toxicity is still the subject of considerable research. With microsome incubation assays in vitro and HPLC methods, the inhibition of rat liver CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A enzymes by rhein were studied kinetically. The results showed the most inhibition of CYP2E1 by rhein (K(i) = 10 microm, mixed); CYP3A and CYP2C9 were also inhibited by rhein, K(i) = 30 microm (mixed) and K(i) = 38 microm (mixed), respectively; rhein revealed some inhibition of CYP1A2 (K(i) = 62 microm, uncompetitive) and CYP2D6 (K(i) = 74 microm, mixed). Drug-drug interactions, especially cytochrome P450 (CYP)-mediated interactions, cause an enhancement or attenuation in the efficacy of co-administered drugs. Inhibition of the five major CYP enzymes observed for rhein suggested that changes in pharmacokinetics of co-administered drugs were likely to occur. Therefore, caution should be paid to the possible drug interaction of medicinal plants containing rhein and CYP substrates.

[Proteasome inhibitors sensitize ovarian cancer cells to paclitaxel induced apoptosis].

OBJECTIVE: To explore the sensitivity of ovarian cancer cell line SKOV3 to paclitaxel, proteasome inhibitors, bortezomib, and their combination. METHODS: The methyl thiazolyl tetrazolium (MTT) assay was applied to examine the cell viability after treatment. The annexin V-propidium iodide apoptosis detection kit was used to determine the apoptosis rate of different groups. Western blot assay was used to evaluate the expression levels of phosphorylated protein kinase B (AKT) and glycogen synthase kinase-3 beta (GSK-3beta). RESULTS: In MTT assay, the cell viability ratios of the combination group at serial time points from 12, 24, 36, 48 and 72 hours were (65.2 +/- 5.8)%, (58.3 +/- 14.4)%, (35.3 +/- 5.0)%, (19.2 +/- 1.5)%, and (11.4 +/- 2.5)%, which were significantly lower than those of the paclitaxel group (P < 0.05). After drug treatments, apoptosis rates of paclitaxel group, bortezomib group and the combination group were (14.7 +/- 0.5)%, (15.1 +/- 0.8)% and (20.5 +/- 0.7)% respectively. The rate of the combination group was significantly higher than that of non-treated group and paclitaxel group (P < 0.05). Western blot assay showed the changes in expression levels of phosphorylated AKT and GSK-3beta, which were decreased significantly after paclitaxel and bortezomib combination treatment [(3.2 +/- 0.8)%, (19.3 +/- 0.4)%; P < 0.05]. CONCLUSIONS: The lethal effect of paclitaxel on tumor cells could be increased significantly by its combination with proteasome inhibitors, bortezomib. The AKT/GSK-3beta signaling pathway plays an important role in the molecular mechanism of the combination treatment.

[Effects of oxymetazoline hydrochloride on ex vivo human nasal cilia movement measured with high-speed digital microscopy].

OBJECTIVE: To investigate the effects of oxymetazoline hydrochloride on ex vivo human nasal cilia movement. METHODS: Ciliary beat frequency (CBF) of cultured human nasal epithelial cells was measured by high-speed digital microscopy in HBSS and oxymetazoline hydrochloride of different concentrations in 20 minutes. RESULTS; CBF of cultured nasal epithelial cells in HBSS and 0.25 g/L oxymetazoline hydrochloride did not show significant changes in 20 minutes (F = 0.098, P = 1.00). However, in 0.50 g/L and 1.00 g/L oxymetazoline hydrochloride, CBF increased slightly in 3 -4 minutes and reached the apex, then decreased gradually. At the end of observation, CBF showed no significant difference in 0.50 g/L, (F = 2.94, P = 0.05) but there was a significant lower CBF in 1.00 g/L. In the first 3 minutes, the CBF in 2.00 g/L oxymetazoline hydrochloride was stable, and then slowed gradually. After 16 minutes, there was significant difference. In initial, the highest normalized CBF of each group showed no significant difference. However, the lowest normalized CBF of 1.00 and 2.00 g/L oxymetazoline hydrochloride showed a significant difference with HBSS, 0.25 and 0.50 g/L oxymetazoline hydrochloride. CONCLUSIONS: Oxymetazoline had a concentration-dependent inhibitory effect on cultured human nasal CBF from 0.25 to 2.00 g/L. The inhibitory effect increased with the concentration going up. Oxymetazoline hydrochloride of 0.50 g/L might be the optimal choice for clinical application.

[Effects of ephedrine on human nasal cilia movement measured with high-speed digital microscopy].

OBJECTIVE: To investigate the effects of ephedrine on human nasal cilia movement. METHODS: Ciliary beat frequency (CBF) of cultured human nasal epithelial cells was measured by high-speed digital microscopy in HBSS and ephedrine solution of different concentrations in 10 minutes. RESULTS: CBF of cultured nasal epithelial cells exposed to HBSS showed no significant changes in 10 minutes. However, in 2.5 g/L , 5 g/L, 10 g/L and 20 g/L ephedrine solution, CBF increased significantly in 1-2 minutes and reached the apex, then it decreased gradually, at the 10th minute. CBF of the samples exposed to 2.5 g/L and 5 g/L ephedrine solution were slower than those in HBSS, but no significant changes were found. However, in 10 g/L and 20 g/L ephedrine solution, CBF decreased significantly when compared with samples in sHBSS. With the concentrations from 2.5 g/L to 20 g/L ephedrine, the increment was independent on the concentration, the inhibitory effect was dependent on the concentration. CONCLUSIONS: In initial time, 2. 5 g/L-20 g/L ephedrine stimulated CBF, then 10 g/L-20 g/L ephedrine inhibited CBF. The stimulation of 2.5 g/L and 5 g/L ephedrine on CBF was longer than that of 10 g/L and 20 g/L ephedrine. 5 g/L ephedrine had maximum stimulatory effect without obvious inhibitory effect on cultured human nasal CBF.

Androgen-regulated formation and degradation of gap junctions in androgen-responsive human prostate cancer cells.

The constituent proteins of gap junctions, called connexins (Cxs), have a short half-life. Despite this, the physiological stimuli that control the assembly of Cxs into gap junctions and their degradation have remained poorly understood. We show here that in androgen-responsive human prostate cancer cells, androgens control the expression level of Cx32-and hence the extent of gap junction formation-post-translationally. In the absence of androgens, a major fraction of Cx32 is degraded presumably by endoplasmic reticulum-associated degradation, whereas in their presence, this fraction is rescued from degradation. We also show that Cx32 and Cx43 degrade by a similar mechanism. Thus, androgens regulate the formation and degradation of gap junctions by rerouting the pool of Cxs, which normally would have been degraded from the early secretory compartment, to the cell surface, and enhancing assembly into gap junctions. Androgens had no significant effect on the formation and degradation of adherens and tight junction-associated proteins. The findings that in a cell culture model that mimics the progression of human prostate cancer, degradation of Cxs, as well as formation of gap junctions, are androgen-dependent strongly implicate an important role of junctional communication in the prostate morphogenesis and oncogenesis.

[Expression and analysis of biological activity of the recombination anthrax edema factor].

Anthrax toxin consists of three separate proteins, protective antigen (PA), lethal factor (LF) and edema factor (EF). EF is bacterial adenylate cyclase which, upon activation by its eukaryotic cofactor, calmodulin, causes a rapid increase in the intracellular cAMP level of host cells. EF can reduce the protective ability of host animal. In order to further research the mechanism of anthrax toxin, the expression plasmid was constructed and the structural gene for anthrax edema factor (EF) was expressed in Escherichia coli. Recombinant EF (rEF) was purified to homogeneity by a three-step procedure involving metal chelating affinity chromatography, cation-exchange chromatography and gel chromatography. From 1 liter of culture, 5mg of biologically active EF was easily purified. Rabbits were immuned with rEF, anti-EF antibodies were prepared and can neutralize rEF in cells. Tests in vitro proved rEF have good biological activity. rEF can competed the binding regions of PA with rLF in J774A.1 and CHO cells. rEF and rLF can restrain each other by competition. The successful expression of rEF has placed a solid foundation for the research on toxicity mechanism of EF, and screening for inhibitors against EF.

Impaired trafficking of connexins in androgen-independent human prostate cancer cell lines and its mitigation by alpha-catenin.

Gap junctions, composed of connexins, provide a pathway of direct intercellular communication for the diffusion of small molecules between cells. Evidence suggests that connexins act as tumor suppressors. We showed previously that expression of connexin-43 and connexin-32 in an indolent prostate cancer cell line, LNCaP, resulted in gap junction formation and growth inhibition. To elucidate the role of connexins in the progression of prostate cancer from a hormone-dependent to -independent state, we introduced connexin-43 and connexin-32 into an invasive, androgen-independent cell line, PC-3. Expression of these proteins in PC-3 cells resulted in intracellular accumulation. Western blot analysis revealed a lack of Triton-insoluble, plaque-assembled connexins. In contrast to LNCaP cells, connexins could not be cell surface-biotinylated and did not reside in the cell surface derived endocytic vesicles, in PC-3 cells, suggesting impaired trafficking to the cell surface. Intracellular accumulation of connexins was observed in several androgen-independent prostate cancer cell lines. Transient expression of alpha-catenin facilitated the trafficking of both connexins to the cell surface and induced gap junction assembly. Our results suggest that impaired trafficking, and not the inability to form gap junctions, is the major cause of communication deficiency in human prostate cancer cell lines.