Neuroprotective properties of aucubin in diabetic rats and diabetic encephalopathy rats.

In this study, we determined the neuroprotective effect of aucubin on diabetes and diabetic encephalopathy. With the exception of the control group, all rats received intraperitoneal injections of streptozotocin (STZ; 60 mg/kg) to induce type 1 diabetes mellitus (DM). Aucubin (1, 5, 10 mg/kg ip) was used after induction of DM (immediately) and diabetic encephalopathy (65 days after the induction of diabetes). The diabetic encephalopathy treatment groups were divided into short-term and long-term treatment groups. Treatment responses to all parameters were examined (body weight, plasma glucose, Y-maze error rates and proportion of apoptotic cells). In diabetic rats, aucubin controlled blood glucose levels effectively, prevented complications, and improved the quality of life of diabetic rats. In diabetic encephalopathy, aucubin significantly rescued neurons in the hippocampal CA1 subfield and reduced working errors during behavioral testing. The significant neuroprotective effect of aucubin could be seen not only in the short term (15 days) but also in the long term (45 days), which was a highly encouraging finding. These data suggest that aucubin may be a potential neuroprotective agent.

Protective effects of aucubin on H2O2-induced apoptosis in PC12 cells.

The present study investigated the neuroprotective effects of aucubin on hydrogen peroxide (H2O2)-induced apoptosis in PC12 cells. Exposure of PC12 cells to 0.25 mm H2O2 induced a leakage of lactate dehydrogenase and decreased cell viability, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In a dose over 0.1 mm, aucubin increased PC12 cellular viability and markedly attenuated H2O2-induced apoptotic cell death. Quantitation of apoptosis by flow cytometry indicated that aucubin inhibited H2O2-induced apoptosis in PC12 cells. Nuclear damage was alleviated by aucubin, as shown by Hoechst staining. In addition, the levels of malondialdehyde were reduced and the activity of superoxide dismutase, catalase and glutathione peroxidase was augmented in these cells. These results indicated that aucubin inhibited H2O2-induced apoptosis in PC12 cells through regulation of the endogenous oxidant-antioxidant balance. Our results suggest that aucubin is a potential protective agent for the treatment of oxidative-stress-induced neurodegenerative disease.

Characterization of chicken egg yolk immunoglobulins (IgYs) specific for the most prevalent capsular serotypes of mastitis-causing Staphylococcus aureus.

The objective of this in vitro study was to evaluate the potential of egg yolk immunoglobulins (IgYs) for treating mastitis caused by Staphylococcus aureus. Specific IgY against type 5 (IgY-T5), type 8 (IgY-T8) and type 336 (IgY-T336) S. aureus strains were obtained by immunizing hens with whole cell vaccines and the IgY produced were then purified to around 80% purity using a water dilution method coupled with salting out and ultra-filtration. Enzyme-linked immunosorbent assay indicated that the IgY specifically targeted the three homologous strains. A growth inhibition assay was performed in Columbia broth (non-encapsulated form) and phosphate-buffered saline (encapsulated form) for an 8h incubation. The results showed that IgY-T336 significantly inhibited (but only 1.5 log units; P<0.01) the growth of all three strains at 15 mg/ml in the Columbia broth. In contrast, the same concentrations of IgY-T5 and IgY-T8 did not show obvious bacteriostatic activity against the two homologous strains. In phosphate buffered saline, no inhibition of the two encapsulated strains was observed with IgY-T5, IgY-T8 and IgY-T336. However, IgY-T336 reduced live bacteria by 1.0 log unit against strain 336 compared with the control. An internalization test indicated that all of the specific IgY (at 5mg/ml) significantly (about 3.0 log units of the control; P<0.01) blocked the internalization of their homologous strains by bovine mammary epithelial cells (MAC-T cells) within 6h. These results suggested that research on the application of IgY as a treatment for mastitis caused by S. aureus should be focused on the internalization inhibition activity rather than on the growth inhibition activity of the IgY.

Aucubin modulates Bcl-2 family proteins expression and inhibits caspases cascade in H2O2-induced PC12 cells.

In this study, the effect of aucubin on H(2)O(2)-induced apoptosis was studied by using a rat pheochromocytoma (PC12) cell line. We have analyzed the apoptosis of H(2)O(2)-induced PC12 cells, H(2)O(2)-induced apoptosis appeared to correlate with lower Bcl-2 expression, higher Bax expression and sequential activation of caspase-3 leading to cleavage of poly-ADP-ribose polymerase (PARP). Aucubin not only inhibited lower Bcl-2 expression, high Bax expression, but also modulated caspase-3 activation, PARP cleavage, and eventually protected against H(2)O(2)-induced apoptosis. These results indicated that aucubin can obstruct H(2)O(2)-induced apoptosis by regulating of the expression of Bcl-2 and Bax, as well as suppression of caspases cascade activation.

Chitosan-alginate microcapsules for oral delivery of egg yolk immunoglobulin (IgY): effects of chitosan concentration.

In our previous study, chitosan-alginate microcapsules were developed to protect egg yolk immunoglobulin (IgY) from gastric inactivation. The present study was undertaken to determine the effect of chitosan concentration (0-0.8%; w/v) on various properties of the microcapsules in order to produce the optimum chitosan-alginate microcapsules for use in the oral delivery of IgY. The properties investigated included microcapsule morphology, loading capacity for IgY (expressed as the IgY loading percentage, w/w, of microcapsules), encapsulation efficiency (EE%), in vitro gastroresistance, and IgY release. IgY loading percentage and EE% were both highest at 0.2% (w/v) chitosan, and, above this level, further increases were not observed. The stability of IgY in simulated gastric fluid (pH 1.2) was significantly improved by encapsulation in alginate microcapsules (IgY retained 43.5% of its activity) and was further improved by including chitosan at any of the chitosan concentrations assessed (IgY retained an average of 69.4% activity) although there was no difference in protection of gastric inactivation among concentrations of chitosan varying from 0.05% to 0.8% (w/v). Higher chitosan concentrations (i.e., >/=0.2%; w/v) prolonged the release of IgY from the microcapsules during simulated intestinal fluid incubation (pH 6.8). However, above the 0.2% (w/v) level, no significant differences were observed. We conclude that the optimum chitosan concentration for microencapsulation is 0.2% (w/v).

Aucubin prevents loss of hippocampal neurons and regulates antioxidative activity in diabetic encephalopathy rats.

In this study, the neuroprotection of aucubin and its mechanism were evaluated in the rat model of diabetic encephalopathy. Diabetes mellitus (DM) rats were stratified by cognitive capability (CC), and assigned to four treatment groups for aucubin treatment (doses of 0, 1, 5 or 10 mg/kg aucubin), with a further two groups of non-DM rats ranked by CC as controls for aucubin (doses of 0 or 5 mg/kg aucubin). Neuroprotection was estimated by the indexes of behavior and histology. Behavioral testing was performed in a Y-maze. The surviving neurons in CA1-CA4 and subiculum (SC) of the hippocampus were counted under a microscope. In addition, the apoptotic neurons in the CA1 of the hippocampus were also examined by using TUNEL staining. In order to clarify the mechanism of aucubin's neuroprotection, the activities of endogenous antioxidants and nitric oxide synthase (NOS) together with the content of lipid peroxide in the hippocampus were assayed. The results proved that aucubin significantly reduced the content of lipid peroxide, regulated the activities of antioxidant enzymatic and decreased the activity of NOS. All these effects indicated that aucubin was a potential neuroprotective agent and its neuroprotective effects were achieved, at least in part, by promoting endogenous antioxidant enzymatic activities.

Chitosan-alginate microcapsules for oral delivery of egg yolk immunoglobulin (IgY): in vivo evaluation in a pig model of enteric colibacillosis.

In our previous study, the applicability of chitosan-alginate microcapsules for oral delivery of egg yolk immunoglobulin (IgY) was established in a simulated gastrointestinal tract environment. The objective of the present study was to evaluate the protective efficacy of microencapsulated IgY against K88+ ETEC (enterotoxigenic Escherichia coli)-induced diarrhea in 40-day-old pigs. Groups of pigs orally challenged with 10(11) cfu/mL of K88+ ETEC were fed with non-encapsulated IgY, microencapsulated IgY and aureomycin-treated feed respectively. The clinical response of each group was monitored and evaluated in terms of lethargy, inappetence, occurrence of diarrhea, fecal consistency score, weight loss and recovery rate. The results showed that treatment of infected pigs with microencapsulated IgY significantly (P<0.05) reduced the K88+ ETEC-induced diarrhea at 24 h post-infection. In contrast, the diarrhea-reducing effect of non-encapsulated IgY was delayed (only evident after 72 h) while normal saline-treated pigs (controls) continued to suffer from diarrhea and dehydration. Similarly, weight gain in microencapsulated IgY-treated pigs was better and significantly different (P<0.05) than in non-encapsulated IgY and saline-treated controls. Collectively, these results support previous in vitro observations showing that chitosan-alginate microcapsules can be an effective method of protecting IgY from gastric inactivation, enabling its use for the widespread prevention and control of enteric diseases.

Efficacy of specific egg yolk immunoglobulin (IgY) to bovine mastitis caused by Staphylococcus aureus.

The objective of this study was to estimate the efficacy of specific egg yolk immunoglobulin (IgY) to bovine mastitis caused by Staphylococcus aureus. Eighteen lactating cows with clinical mastitis and 18 lactating cows with experimental mastitis (1 quarter per cow) were randomly assigned to three treatments: IgY (20mg/ml) infusion, penicillin (100mg/ml) infusion and no infusion. Treatments for clinical mastitis and experimental mastitis were performed by a 6-day course of intramammary infusion with a dosage of 10ml at an interval of 12h. Milk samples were collected at morning milking time for testing color, clot, somatic cell counts (SCC) and bacterial count. For most of the cows treated with IgY and penicillin, the milk color and clot recovered to normal form during the therapy course. The milk SCCs and bacterial counts of treated cows decreased compared to those of untreated cows (p<0.05). The cure rates by IgY for experimental and clinical mastitis were 83.3% and 50%, respectively, and those by penicillin were 66.7% and 33.3%, respectively. These results showed the potential of specific IgY to be an alternative therapy for mastitis caused by S. aureus.

Protective effect of Acanthopanax senticosus extract against endotoxic shock in mice.

AIM OF THE STUDY: In this study, we evaluated protective effect of Acanthopanax senticosus extract (ASE) and a possible signaling pathway involved during endotoxic shock induced by intraperitoneal injection lipopolysaccharide (LPS) and D-galactosamine (D-GalN) in BALB/c mice. MATERIALS AND METHODS: Mice were intraperitoneal administrated with ASE (100, 200 or 400mg/kg) prior to injection of 50 microg/kg LPS and 1g/kg D-GalN. The levels of tumor necrosis-alpha (TNF-alpha) and interleukin-10 (IL-10) in serum and liver. Nitric oxide (NO) production in serum and inducible nitric oxide synthase (iNOS) protein level were investigated. Nuclear factor-kappa B (NF-kappaB) activation in liver was determined. Furthermore, we evaluated the effect of ASE pretreatment on infiltration of inflammatory cells into the heart, liver and lung of mice. RESULTS: Treatment of mice with ASE prior to LPS/D-GalN injection significantly improved the survival rate. ASE pretreatment inhibited the elevation of TNF-alpha in serum and liver. ASE also decreased iNOS level in liver and the overproduction of nitric oxide (NO) in serum. In addition, IL-10 levels in serum and liver were markedly enhanced. ASE pretreatment inhibited NF-kappaB activation in liver of mice. Moreover, infiltration of inflammatory cells into the heart, liver and lung of mice was also attenuated by ASE pretreatment. CONCLUSIONS: These results suggested that ASE protected mice against LPS/D-GalN-induced endotoxic shock involving inhibition of NF-kappaB activation, which caused down-regulation of TNF-alpha and involved up-regulation of IL-10. Acanthopanax senticosus may thus prove beneficial in the prevention of endotoxic shock.

Inhibition of inducible nitric oxide synthase by Acanthopanax senticosus extract in RAW264.7 macrophages.

AIM OF THE STUDY: The herb Acanthopanax senticosus (Siberian ginseng) has long been used as a traditional medicine. However, little is known about anti-inflammatory effects and its mechanisms of action. Excess production of nitric oxide (NO) is one of the characteristics of inflammation. In this study we examined the effects of A. senticosus extract (ASE) on NO production and inducible nitric oxide synthase (iNOS) gene expression in lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma)-stimulated RAW264.7 macrophages and investigated its mechanisms of anti-inflammatory activity. MATERIALS AND METHODS: RAW264.7 macrophages were treated with 10 microg/ml LPS plus 20U/ml IFN-gamma in the presence or absence of ASE. NO production and iNOS gene expression were investigated. We further evaluated the effect of ASE on oxidative stress-sensitive transcription nuclear factor-kappa B (NF-kappaB) activation. RESULTS: ASE significantly suppressed NO production and iNOS gene expression in a dose-dependent manner. ASE also reduced DNA-binding activity of NF-kappaB in LPS plus IFN-gamma stimulated RAW264.7 macrophages. Further studies indicated that LPS plus IFN-gamma-induced inhibitory factor-kappa B alpha (I-kappaBalpha) degradation and p65 nuclear translocation were inhibited in RAW264.7 macrophages exposed to ASE. Moreover, ASE inhibited the LPS plus IFN-gamma mediated increase in intracellular peroxides production. CONCLUSIONS: These results suggest ASE suppresses iNOS gene expression through the inhibition of intracellular peroxides production, which has been implicated in the activation of NF-kappaB.

Acanthopanax senticosus suppresses reactive oxygen species production by mouse peritoneal macrophages in vitro and in vivo.

Excess production of reactive oxygen species by macrophages has been implicated in many inflammatory diseases. The present study investigated the inhibitory effect of the stem bark extract of Acanthopanax senticosus on the production of superoxide anion and hydrogen peroxide in mouse peritoneal macrophages in vitro and in vivo. Exposure of mouse peritoneal macrophages to A. senticosus extract significantly suppressed superoxide anion production induced by zymosan in a dose-dependent manner. Similarly, exposure of mouse peritoneal macrophages to A. senticosus extract significantly inhibited hydrogen peroxide production induced by phorbol 12-myristate 13-acetate (PMA) in a dose-dependent manner. Intraperitoneal administration of A. senticosus extract to KM mice reduced the ex vivo production of zymosan induced-superoxide anion and PMA-induced hydrogen peroxide by their peritoneal macrophages. Exposure to A. senticosus extract did not affect the cell viability or systemic toxicity. A. senticosus inhibited reactive oxygen species production by mouse peritoneal macrophages in vitro and in vivo and may be partly responsible for the antiinflammatory function.

Characterization of specific egg yolk immunoglobulin (IgY) against mastitis-causing Escherichia coli.

The objective of this study was to estimate the in vitro activity of egg yolk immunoglobulin (IgY) against mastitis-causing Escherichia coli. Specific IgY was produced by hens immunized with formaldehyde killed E. coli O111 in long-standing immunization response (titer > or =6400 for 100 days) and was isolated from yolks with a purity of 86% by water dilution, salt precipitations and ultrafiltration. Enzyme-linked immunosorbent assay (ELISA) indicated the produced IgY specifically targeted E. coli O111 and five other E. coli strains which were isolated from mastitic cows. The growth inhibition activity of the specific IgY to bacteria was dose-dependent with an effective concentration of 20mg purified IgY per milliliter. The phagocytic activity of E. coli either by milk macrophages (MPhi) or by polymorphonuclear neutrophil leukocytes (PMN) in the presence of specific IgY was significantly higher than that with nonspecific IgY or without IgY (p<0.05), suggesting that it enhanced phagocytic activity. The current work suggests that this specific IgY has potential as a therapeutic treatment for mastitis in dairy cows.

Antioxidant and pancreas-protective effect of aucubin on rats with streptozotocin-induced diabetes.

Oxidative stress has been suggested as a contributory factor in development and complication of diabetes. The aim of the present study was to determine the protective effect of aucubin on lipid peroxidation and activities of antioxidant defense systems and to conduct immunohistochemical evaluation of pancreas in streptozotocin-induced diabetic rats. Lipid peroxidation was determined by assessing the concentration of malondialdehyde and activities of antioxidant enzymes - catalase, glutathione peroxidase and superoxide dismutase in liver and kidneys of rats were determined. Changes of blood glucose and immunohistochemical evaluation on pancreas were also investigated as part of the pathology of diabetes. In our study, aucubin treatment lowered blood glucose. Diabetic rats exhibited an increase in the level of lipid peroxidation and decrease in activities of antioxidant enzymes in liver and kidneys as compared to control rats. Administration of aucubin to diabetic rats for 15 days significantly reversed damage associated with diabetes. In addition, diabetic rats showed an obvious decrease in insulin immunoreactivity and the number of beta cells in pancreas, but the pancreas of aucubin-treated rats were improved and the number of immunoreactive beta cells were significantly increased. These results indicated that aucubin may have value as a safe preventive or therapeutic agent against diabetes mellitus.

Acanthopanax senticosus inhibits nitric oxide production in murine macrophages in vitro and in vivo.

Excess nitric oxide (NO) production has been implicated in inflammatory diseases. The present study investigated the inhibitory effect of the stem bark extract of Acanthopanax senticosus (A. senticosus) on NO production in murine macrophages in vitro and in vivo. In vitro exposure of RAW264.7 cells to 1, 10, 50, 100, 250, 500 and 1000 microg/mL of A. senticosus extract significantly suppressed NO production induced by lipopolysaccharide (LPS) and interferon gamma (IFN-gamma) in a dose-dependent manner. In vitro exposure of mouse resident peritoneal macrophages to 1, 10, 100 and 1000 microg/mL of A. senticosus extract significantly suppressed NO production induced by LPS and IFN-gamma in a dose-dependent manner. In vivo administration of A. senticosus extract (50, 100 and 200 mg/kg) to KM mice dose-dependently inhibited LPS and IFN-gamma induced production of NO in isolated mouse peritoneal macrophages ex vivo. Exposure to A. senticosus extract had no effect on cell viability and systemic toxicity. The results demonstrated that the stem bark extract of A. senticosus extract inhibits NO production in murine macrophages in vitro and in vivo.

Chitosan-alginate microcapsules for oral delivery of egg yolk immunoglobulin (IgY).

Chitosan-alginate microcapsules were evaluated as a method of oral delivery of IgY antibodies. Physical characteristics, encapsulation efficiency (EE%), the loading capacity for IgY (IgY loading percentage, %, w/w of microcapsules), gastro-resistance, and release characteristics of these microcapsules in vitro under varying pH were investigated. Optimum physical factors were established for preparation of homogeneous, spherical, and smooth microcapsules. IgY loading% was not significantly altered by pH of the encapsulation medium. Encapsulation efficiency was highest (73.93%) at a pH of 3.5, above which EE% decreased significantly (p < 0.05). IgY was released from microcapsules upon exposure to simulated intestinal fluid (SIF, pH 6.8), and decreasing pH increased significantly IgY release (p < 0.05). The stability of IgY in simulated gastric fluid (SGF, pH 1.2) was greatly improved by encapsulation in chitosan-alginate microcapsules, and the residual activity was not affected by pH of the encapsulation medium. Moreover, microencapsulated IgY was significantly resistant to pepsin hydrolysis. This approach may enable intact IgY to reach target microorganisms within the lower digestive tract.

Sequential treatment with lamivudine and interferon-alpha monotherapies in hepatitis B e antigen-negative Chinese patients and its suppression of lamivudine-resistant mutations.

OBJECTIVES: To assess the efficacy of sequential treatment with lamivudine and interferon-alpha monotherapies in Chinese patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B. METHODS: One hundred and sixty-two patients with HBeAg-negative chronic hepatitis B were included in this study. Ninety-eight were treated with lamivudine alone (100 mg per day) for 48 weeks (group B). Sixty-four were treated with lamivudine alone (100 mg per day) for 20 weeks, then combined with interferon-alpha-2b (5 million units three times per week) for 4 weeks and then treated for another 24 weeks with interferon-alpha-2b alone (5 million units three times per week) (group A). All patients were followed for an additional 24 weeks. RESULTS: After 48 weeks of treatment, the percentage of patients with normalization of alanine aminotransferase (ALT) levels or hepatitis B virus (HBV) DNA levels below 1000 copies/mL was not significantly different between the lamivudine monotherapy group (55.10% and 55.10%, respectively) and the sequential treatment group (59.36% and 56.25%, respectively). The percentage of patients with normalized ALT levels was significantly higher in group A (53%) than in group B (36%) at week 72 (P<0.05). The percentage of patients with lamivudine-resistant mutations was significantly higher with lamivudine monotherapy (22.45%) than with sequential therapy (P<0.05). CONCLUSIONS: Sequential treatment of chronic hepatitis B with lamivudine and interferon-alpha monotherapies is as effective as lamivudine-alone treatment in Chinese patients. However, sequential treatment can significantly suppress the emergence of lamivudine-resistant mutations.

Rapid quantitation of lamivudine-resistant mutants in lamivudine treated and untreated patients with chronic hepatitis B virus infection.

BACKGROUND: Long-term lamivudine treatment induces emergence of lamivudine-resistant hepatitis B virus (HBV) in a significant number of patients with chronic HBV infection. Rapid and quantitative methods to determine the percentage of lamivudine-resistant mutants in total HBV are important during lamivudine therapy. METHODS: We established a quantitative real-time PCR method with selective primers and TaqMan probe to detect the percentage of lamivudine-resistant mutants in total HBV without the need of external DNA standards. This percentage was calculated as the PCR efficiency raised to the differences between threshold cycle number (DeltaCt) of mutant and control reactions. Clones of the HBV polymerase gene containing the different YMDD variants were diluted in series and tested. Serum samples from 145 lamivudine-treated and 98 untreated patients with chronic hepatitis B virus infection were analyzed using this method and compared with DNA sequencing. RESULTS: As little as 0.1% mutant plasmids in 10(6)-10(9) copies/ml of wild-type plasmids were detected. Among the 145 patients treated with lamivudine, 42 of them had mutants with percentages of 5-100%. In six discordant results between real-time PCR and DNA sequencing, real-time PCR detected mutants with percentages of 5-20%, which were concordant with subclone sequencing. Five of 98 lamividine-untreated patients had mutants of 10-20% in wild-type virus populations. Compared to DNA sequencing, real-time PCR was fast and cost-effective. CONCLUSION: This real-time PCR is a rapid, sensitive and cost-effective method for relative quantitation of YMDD mutants of HBV.

[The new advance of coupled transcription and translation: translation within the nuclei in eukaryotes].

It is well known that the processes of transcription and translation are coupled in prokaryotes. However, in eukaryotes, shortly after the transcription of the primary transcript begins, modifications and processing occur. After the mature mRNA moleculars are transported from the nuclei to the cytoplasm, the translations begin. It shows that the processes of transcription and translation are not coupled in eukaryotes. But now Iborra et al localized translation sites with [3H] lysine or lysyl-tRNA tagged with biotin or BODIPY in mammalian cells and found that there exited coupled transcription and translation within the nuclei. They estimated that the nuclear translation accounted for about 10% to 15% of protein synthesis in the cell.

[Construction and expression of recombinant human thymosin alpha1 fusion gene in Pichia pastoris].

The human Thymosin alpha1 (hTalpha1) gene was synthesized according to the optimal codons of Pichia pastoris and was fused in 5' terminal of ribosomal protein (RP) gene using over lapping polymerase chain reaction. The fusion gene was inserted into expression vector of pPIC3. 5K and was transformed into HIS4 mutant strain GS115 by electroporation. Both SDS-PAGE and Western blot indicated that this fusion protein was expressed. The expression level was about 25mg/L.