Nisin is a cationic antimicrobial peptide produced by some lactic acid bacteria. However, expression of nisin resistance protein (NSR) could confer nisin resistance on some non-nisin-producing Lactococcus lactis. To deeply elucidate molecular mechanism underlying NSR-mediated nisin resistance, an NSR mutant with N-terminal 38 amino acid residues deleted (NSR?38) was overexpressed in Escherichia coli by fusion with GST. Purified NSR?38 was obtained through glutathione (GSH) affinity chromatography followed by cleavage of GST tag. Putative proteolytic activity of NSR?38 was determined in vitro against nisin. Antimicrobial activity analysis revealed that nisin lost its bactericidal activity after incubation with NSR?38. Further reversed-phase high performance liquid chromatography (RP-HPLC) analysis indicated that NSR?38 displayed proteolytic activity against nisin, thus inactivating the antimicrobial peptide. The current study paves the way for in-depth functional studies on NSR.

Objective To evaluate the role of prostaglandin E2 (EP) receptors in H9c2 cardiomyocyte hypertrophy induced by prostaglandin E2 (PGE2).Methods Primary cultured H9c2 cardiomyocytes were seeded in culture flasks (3 ml/flask) or in 24-well plate (1 ml/hole) or 6-well plate (2 ml/hole) with density of 4 × 104/ml.The cells were randomly divided into 4 groups (n=24 each): control group (group C),PGE2 group,AH6809 (EP1 and EP2 receptor antagonist) group (group A) and GW627368X (EP4 receptor antagonist) group (group G).The cells were continuously cultured for 48 h.PGE2 (final concentration 1 μmol/L) was added to the culture medium in PGE2 group.PGE2 (final concentration 1 μmol/L) and A H6809 (final concentration 10 μmol/L) were added to the culture medium in group A.PGE2 (final concentration 1 μmol/L) and GW627368X (final concentration 10 μmol/L) were added to the culture medium.The cells were then cultured for 48 h in groups PGE2,A and G.Then the cell morphology was observed by using fluorescent microscope.The cell diameter was measured by using the Image J medical image analysis system.Total protein content in the cells was measured with BCA method.The expression of atrial natriuretic peptide (ANP) mRNA and brain natriuretic peptide (BNP) mRNA in the cytoplasm was determined using RT-PCR.Results Compared with group C,the total protein in the cells and cell diameter were significantly increased,and the expression of ANP mRNA and BNP mRNA in the cytoplasm was up-regulated in groups PGE2,A and G (P ＜ 0.05).Compared with group PGE2,the total protein in the cells and cell diameter were significantly decreased,and the expression of ANP mRNA and BNP mRNA in the cytoplasm was downregulated in group G (P ＜ 0.05),and no significant change was found in the parameters mentioned above in group A (P ＞ 0.05).Conclusion EP4 receptor mediates H9c2 cardiomyocyte hypertrophy induced by PGE2 and the effect is not related to EP1 and EP2.

The effects of ultrafine grinding on the dissolution rates of the effective components in Sanjie Zhentong capsule (SZC) were studied in this experiment. Fine and ultrafine powder of SZC intermediates were made by ordinary grinding and ultrafine grinding technology, and then granulated by wet granulation. SZC were prepared by fine powder, ultrafine powder and ultrafine granules, respectively. With resveratrol and loureirin B as investigated indexes, dissolution rates of the four intermediates in SZC were determined by cup method and HPLC. The dissolution rates of resveratrol in SZC prepared by fine powder, ultrafine powder and ultrafine granules were 26.11%, 63.27%, 67.49%, respectively; and the dissolution rates of loureirin B were 7.160%, 20.29%, 23.05%, respectively. The dissolution rate of resveratrol and loureirin B in SZC prepared by ultrafine granules was the best. D90 size of ultrafine grinding was 13.221 μm and could improve the dissolution rates of resveratrol and loureirin B in SZC.
Capsules ; chemistry ; Drugs, Chinese Herbal ; chemistry ; Particle Size ; Silicones ; chemistry ; Solubility ; Technology, Pharmaceutical ; methods

Objective To detect the expression of VIP1R and VIP2R mRNA in gallbladder tissues of patients with gallbladder diseases. Methods The expression of VIP1R and VIP2R mRNA in gallbladder tissues were detected in 25 patients with gallstone, 8 patients with gallbladder polyps and 7 control liver transplantation donors by RT-PCR. Results The VIP2R mRNA level of the control group (1. 09 ?0. 58 ) was lower than that of the gallbladder polyps group (1.64?0.56 ),P

AIM To investigate the role of serotonergic projection from dorsal raphe nuclei (DRN) to basolateral amygadaloid (BLA) in the regulation of sleep and waking state. METHODS stereotaxic microinjection and polysomnography were employed. RESULTS Microinjection of L Glu into the DRN caused an enhancement of wake (W) and a decrease of slow wave sleep (SWS) and paradoxical sleep (PS). However, microinjection of L Glu into the DRN plus bilateral microinjection of methysergide (MS) into the BLA reversed the effects of L Glu. Microinjection of PCPA into the DRN caused an enhancement of SWS and a decrease of W. Microinjection of PCPA into the DRN plus bilateral microinjection of 5 HTP into the BLA reversed the effects of PCPA. CONCLUSION These results suggest that the role of the DRN in the regulation of sleep and waking state is partly mediated by serotonergic projection from the DRN to the BLA.

The chromatographic fingerprint was established by eluting with the mobile phase consisted of acetonitrile and 0.2% formic acid water on an Agilent TC-C18 (2) column (4.6 mm x 250 mm, 5 microm). Six chromatographic peaks were identified by HPLC-MS/MS method. Ten batches of Glycyrrhizea Radix et Rhizoma Praeparata Cum Melle were determined, and the similarity was arranged from 0.72 to 0.99. Good precision, stability and repeatability were obtained, and this study provides a reference for the quality control of Glycyrrhizea Radix et Rhizoma Praeparata Cum Melle.
China ; Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; chemistry ; Glycyrrhiza uralensis ; chemistry ; Mass Spectrometry ; Quality Control ; Rhizome ; chemistry

Objective:To explore the alteration of brain‐derived neurotrophic factor (BDNF) signaling and the influ‐ence of irbesartan on it in hippocampus of angiotensin‐converting enzyme 2 (ACE2) knock‐out (KO) mice . Meth‐ods:The 10~11‐week ACE2 KO (Ace2/y ) mice received daily treatment with angiotensin II (Ang II) type 1 (AT1) receptor blocker irbesartan (50 mg/kg) or placebo for two weeks. The wild‐type mice (WT ,Ace2+ /y ) were regarded as normal control. Western blotting method was used to measure levels of BDNF and extracellular signal regulated kinase 1/2 (ERK1/2) in the mice hippocampus. Radioimmunoassay was used to measure plasma Ang level in mice . Results :Compared with normal WT control mice ,there were significant down‐regulations of BDNF protein expres‐sion [ (1 ± 0.16) vs .(0.54 ± 0.16)] in hippocampus and plasma Ang‐ (1‐7) level [ (55.6 ± 7.5) pg/ml vs .(42.8 ± 5.8) pg/ml] ,and significant rise in ERK1/2 phosphorylation [ (1 ± 0.28) vs .(1.79 ± 0.29)] in ACE2 KO mice (P<0.01 all). After irbesartan treatment ,there were significant rise in BDNF protein expression (0.88 ± 0.13) in hippocampus and plasma Ang‐ (1‐7) level [(59.4 ± 8.4) pg/ml] ,and significant reduction in ERK1/2 phosphoryla‐tion level (1.33 ± 0.19) in ACE2 KO mice (P<0.05 or <0.01) .Conclusion:There are BDNF protein expression down‐regulation and enhanced ERK1/2 phosphorylation in hippocampus of ACE2 KO mice. AT1 receptor blockade irbesartan can improve Ang‐ (1‐7 ) level and hippocampus BDNF expression , while reducing hippocampus ERK phosphorylation signal in ACE2 KO mice ,suggesting that AT1 receptor blockade possesses certain brain protective effect.

AIM:To investigate the synergistic anti-proliferation effect of aspirin and 5-fluorouracil on the co-lon cancer cells and its mechanism .METHODS: Colon cancer cells were divided into 4 groups: control group , aspirin group, 5-fluorouracil group and aspirin +5-fluorouracil group .Synergistic anti-proliferation effect of aspirin and 5-fluoroura-cil on the colon cancer cells was observed by MTT assay .Apoptosis-inducing effect and mechanism were detected by Hoechst 33258 staining, caspase activity assay and flow cytometry analysis .The mRNA and protein levels of apoptosis-re-lated proteins were evaluated by real-time PCR and Western blotting .RESULTS:5-Fluorouracil inhibited proliferation of HCT116 and SW620 colon cancer cells effectively , and low concentration of aspirin exerted synergistic inhibitory effect .5-Fluorouracil induced apoptotic morphology and increased caspase activity and sub -G1 phase in HCT116 cells.The synergis-tic effect of aspirin obviously enhanced apoptotic ratio and caspase activity .Moreover , 5-fluorouracil inhibited the mRNA and protein expression of Bcl-2, which was amplified by low concentration of aspirin .CONCLUSION:Aspirin and 5-flu-orouracil had a synergistic anti-proliferation effect on the colon cancer cells through apoptosis pathway .

Objective: To investigate the changes of myo cardial contractile function during myocardial stunning in calcium overload rats and the protective effects of tetrandrine. Methods: Forty-six rats were randomized into control, myocardial ischemia, myocardial stunning, low and high dose of tetrandrine groups. Another 10 rats were used to identify the calcium overload. vitamin D3 (0.3 million Unit/kg) and nicotinic acid were adm inistered. After 16 d when calcium overload occured, left anterior descending ar tery was ligated. Twenty minutes of myocardial ischemia followed by 60 min of re perfusion was induced. The contractile function parameters were determined dynam ically. At the end of experiment, myocardial cytosolic ［Ca2+］i was deter mined in various groups. In tetrandrine groups, tetrandrine (62.2 or 93.6 μmol/ kg ) was administered by gastrogavage daily.After 16 d, the rats undergone the e xperiments mentioned above. Results: Sixteen days after vitamin D3 , nicotinic acid were given, ［Ca2+］i increased by 2.6 folds (146.8±10.8 ) vs (368.5±22.6) nmol/L, (P<0.01). Whereas, ［Ca2+］i in tetrand rine groups were (210.8±16.4) and (198.6±15.3) nmol/L, which were significantl y lower than that of calcium overload group. Twenty minutes of myocardial ische mia resulted in the decrease of dp/dtmax and Vmax in all groups with the most si gnificant in stunning and calcium overload groups. The contractile function rest ored gradually after reperfusion. At all time points, dp/dtmax and Vmax in both tetrandrine groups were higher than those in both stunning and calcium overload groups. And effect with higher dose of tetrandrine were more significant than in low dose of tetrandrine. After 60 min of reperfusion, dp/dtmax in stunning, cal cium overload, low and high dose of tetrandrine groups were 49.7%, 51.5%, 71.0% and 83.4% of that in control, respectively， and Vmax were 55.0%, 49.8%, 73.9% and 77.5% of that in control, respectively. Conclusion: T he myocardial contractile function in vitamin D3-induced calcium overload gro up is impaired. On basis of myocardiocyte calcium overload, transient ischemia l eads to myocardial stunning. At the stage of ischemia, the impaired degree of my ocardial contractile function is similar to that in stunning group, suggesting a t this stage the effect of ischemia on myocardial function is greater than that of calcium overload. Tetrandrine chronically improves the myocardial function in Vitamin D3-induced calcium overload rats.

Objective To investigate the efficacy and safety of domestic exenatide injection versus imported exenatide injection in type 2 diabetic patients with inadequate glycemic control on monotherapy or combination therapy of metformin and insulin secretagogues. Methods A multicenter, randomized, parallel-controlled, and non-inferiority trial was carried out. A total of 240 subjects were randomized at a 1:1 ratio to add domestic exenatide injection (trial group) or imported exenatide injection (control group) on the background therapies. The primary endpoint of efficacy was HbA1C change from baseline to week 16. The secondary endpoints of efficacy were the proportion of HbA1C<7.0%, and the changes in fasting plasma glucose (FPG), 2 h plasma glucose after standard meal (2hPG), 7-point self monitoring of blood glucose (7P-SMBG), and body weight from baseline to week 16. Results Among subjects of per-protocol sets, adjusted mean HbA1C reduction was -1.07% in the trial group versus -1.06% in the control group after 16 weeks of treatment. The lower boundary of the two-sided 95% confidence intervals of the mean HbA1C reduction difference between the trial and control groups was -0.29%, which was more than -0.35%, suggesting that the predefined statistical criterion for non-inferiority was achieved. The proportions of subjects achieving HbA1C<7.0% at the end of the 16-week treatment were 56.19% and 54.08% in the trial and control groups, respectively (P>0.05). The changes in FPG, 2hPG, 7P-SMBG and body weight from baseline to week 16 were comparable between the two groups (all P>0.05). Moreover, the incidences of hypoglycemia and adverse events were similar between the two groups (both P>0.05). Conclusion In type 2 diabetic patients inadequately controlled by monotherapy or combination therapy of metformin and insulin secretagogues, the efficacy of cotreatment with domestic exenatide injection is not inferior to that of imported product ones, with a similar safety profile.