Comparative Study of the Preparation of High-Molecular-Weight Fibroin by Degumming Silk with Several Neutral Proteases.

Removing sericin from the periphery of silk without damage to silk fibroin (SF) to obtain high-molecular-weight SF is a major challenge in the field of SF-based biomaterials. In this study, four neutral proteases, subtilisin, trypsin, bromelain and papain, were used to degum silk, and the degumming efficiency of the proteases and their influence on the molecular weight (MW) of regenerated silk fibroin were studied. The results indicated that all four neutral proteases could remove sericin from silk almost completely, and they caused less damage to SF fibers than Na2CO3 degumming did. The degumming efficiency of trypsin and papain was strong, but they caused relatively high damage to SF, whereas bromelain caused the least damage. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel permeation chromatography and shear viscosity showed that the MWs of regenerated SF derived from neutral protease degumming were significantly higher than that of SF derived from Na2CO3 degumming. The MW of regenerated SF derived from bromelain degumming was the highest, while the MWs of regenerated SF derived from papain and trypsin degumming were relatively low. This study provides an efficient and environmentally friendly biological degumming method for obtaining high-molecular-weight silk fibroin.

A high molecular weight silk fibroin scaffold that resists degradation and promotes cell proliferation.

The regulation of the biodegradation rate of 3D-regenerated silk fibroin scaffolds and the avoidance of premature collapse are important concerns for their effective applications in tissue engineering. In this study, bromelain, which is specific to sericin, was used to remove sericin from silk, and high molecular weight silk fibroin was obtained after the fibroin fibers were dissolved. Afterwards, a 3D scaffold was prepared via freeze-drying. The Sodium dodecyl sulfate-polyacrylamide gel electrophoresis results showed that the average molecular weight of the regenerated silk fibroin prepared by using the bromelain-degumming method was approximately 142.2 kDa, which was significantly higher than that of the control groups prepared by using the urea- and Na2 CO3 -degumming methods. The results of enzyme degradation in vitro showed that the biodegradation rate and internal three-dimensional structure collapse of the bromelain-degumming fibroin scaffolds were significantly slower than those of the two control scaffolds. The proliferation activity of human umbilical vein vascular endothelial cells inoculated in bromelain-degumming fibroin scaffolds was significantly higher than that of the control scaffolds. This study provides a novel preparation method for 3D-regenerated silk fibroin scaffolds that can effectively resist biodegradation, continuously guide cell growth, have good biocompatibility, and have the potential to be used for the regeneration of various connective tissues.

Meta-analysis of Banmao Capsules in adjuvant treatment for non-small cell lung cancer / 中国中药杂志

To systemically evaluate the efficacy and safety of Banmao Capsules in the adjuvant treatment for non-small cell lung cancer(NSCLC). All of randomized controlled trials(RCT) about Banmao Capsules in adjuvant treatment for non-small cell lung cancer were retrieved in PubMed, EMbase, Cochrane Library, CNKI, VIP, CBM, WanFang database from database inception to August 2019. Two researchers extracted data and assessed literature quality separately, and made a Meta-analysis by RevMan 5.3 software. Thirteen trials involving 1 148 patients, including 595 in treatment group and 553 in control group, were enrolled in the review. The Meta-analysis showed that compared with conventional treatment, adjuvant treatment of NSCLC with Banmao Capsules can enhance the objective tumor response rate(RR=1.43,95%CI[1.30,1.58],P<0.01), and the disease control rate(RR=1.16,95%CI[1.11,1.22],P<0.01); improve the quality of life(RR=1.56,95%CI[1.27,1.92],P<0.01); reduce the incidence of myelosuppression(RR=0.41,95%CI[0.26,0.66],P<0.01), gastrointestinal reactions(RR=0.46,95%CI[0.33,0.65],P<0.01), liver and kidney dysfunction(RR=0.44,95%CI[0.29,0.66],P<0.01). The results showed that in the treatment of NSCLC, Banmao Capsules can increase the short-term efficacy, improve the quality of life of patients, and reduce the side effects of platinum-based chemotherapy drugs. More high-quality and large-scale randomized controlled trials are required in the future.

Preventive effect of pentoxifylline on contrast-induced acute kidney injury in hypercholesterolemic rats.

Oxidative stress is an important mechanism of contrast-induced acute kidney injury (CIAKI). The optimal strategy to prevent CIAKI remains unclear. The aim of the present study was to assess the effect of pentoxifylline, a nonspecific phosphodiesterase inhibitor, on the prevention of CIAKI. A total of 32 healthy male Sprague-Dawley rats were randomly divided into normal dietary group (NN; n=8) and a high cholesterol-supplemented dietary group (HN; 4% cholesterol and 1% cholic acid; n=24). At the end of eight weeks, the rats in the high cholesterol diet group were randomly divided into three subgroups (n=8 in each group). CIAKI was induced in two of the subgroups via intravenous injection of the radiocontrast media iohexol (10 ml/kg). Pentoxifylline (50 mg/kg) was administered to one of the iohexol-treated groups via intraperitoneal injection 12 h prior to and following contrast media (CM) injection. Kidney function parameters and oxidative stress markers were then measured. The renal pathological changes were evaluated using hematoxylin and eosin staining and scored semi-quantitatively. In iohexol-injected rats, serum creatinine (Scr), renal pathological scores, renal malondialdehyde (MDA) content, renal NADPH oxidase activity, fractional excretion of sodium (FENa%) and fractional excretion of potassium (FEK%) were significantly increased (P<0.01). The Scr, histologic scores, renal MDA content, NADPH oxidase activity, FENa% and FEK% in the rats treated with pentoxifylline prior to iohexol were observed to be reduced compared with those in rats treated with iohexol alone (P<0.01). This suggests that pentoxifylline significantly attenuates renal injuries, including tubular necrosis and proteinaceous casts induced by CM. It may be concluded that pentoxifylline protected the renal tissue from the nephrotoxicity induced by low-osmolar CM via an antioxidant effect.

Preliminary study of Huai Qi Huang granules delay the development of primary glomerular diseases in human.

OBJECTIVE: To evaluate the effects of Huai Qi Huang (HQH) granules on primary glomerulonephritis patients, and to discuss its possible mechanisms. METHOD: Sixteen patients diagnosed with primary glomerular disease between December 2011 and December 2012 were enrolled. Their blood and urine samples were collected at day 0 (the baseline levels), 30, and 90 of receiving HQH granules orally. Levels of creatinine and cystatin C (Cys-C) in serum and urine, and total protein and albumin in urine were measured by automatic biochemical analyzer. Neutrophil gelatinase-associated lipocalin (NGAL) in serum and urine was tested by ELISA; serum malondialdehyde (MDA) was measured by thiobarbituric acid method, the erythrocyte count in urine was calculated under light microscope. RESULTS: Serum levels of creatinine, MDA, Cys-C and NGAL at day 30 and 90 were significantly lower than the baseline levels. Urinary levels of Cys-C, NGAL, total protein, albumin and erythrocyte counts were also decreased; level of estimated glomerular filtration (eGFR) was increased. CONCLUSION: HQH granules have certain effect on delaying the development of primary glomerular disease with mild proteinuria and hematuresis in patients. This study may supply a new treatment for primary glomerular diseases.

Effects of electroacupuncture preconditioning on jugular vein glucose level and cerebral edema in rats undergoing cerebral ischemia reperfusion that induced injury.

OBJECTIVE: To determine the effects of electroacupuncture (EA) preconditioning on the blood glucose level in jugular vein and water content in brain tissues in rats undergoing cerebral ischemia reperfusion that induced injury. METHODS: 90 healthy male Wister rats were randomly assigned to 3 groups: sham-operation (SH) group, cerebral ischemia reperfusion (IR) group and electroacupuncture (EA) preconditioning plus IR group. EA group was pretreated with EA delivered to acupoints of "Baihui" (Du 20) and "Shuigou" (Du 26) 30 min before cerebral ischemia. RESULTS: No marked difference was observed in brain water content 2 h after procedure in IR group, SH group and EA group. Compared with SH group, the brain water contents in IR group and EA group were significantly higher 6 h after reperfusion and peaked at 48 h (P < 0.01). The blood glucose levels in EA and IR groups were significantly higher than that of SH group 2 h after reperfusion, which peaked at 6 h and tended to decline up to 24 h after reperfusion (P < 0.01). 2 h, 6 h, and 24 h after reperfusion, EA group had significantly lower blood glucose levels than IR group (P < 0.01). CONCLUSION: Electroacupuncture preconditioning can significantly inhibit the augmentation of the blood glucose level and attenuate cerebral edema induced by reperfusion, which leads to alleviation of injury caused by ischemia reperfusion.

Mitochondria-targeted peptides prevent on contrast-induced acute kidney injury in the rats with hypercholesterolemia.

OBJECTIVE: The objective of this study is to evaluate the effect and mechanism of mitochondria-targeted peptides (MTP131 and SPI20) on contrast-induced acute kidney injury (CI-AKI) in rats with hypercholesterolemia. METHOD: Forty SD rats were randomly divided into normal diet group (NN, n = 8) and high cholesterol supplemented dietary group (HN, n = 32). At the end of 8 weeks, the group HN was divided into four subgroups. All Rats were given injection of either diatrizoate (10 mL/kg) or equal volume of normal saline, the rats pretreated with MTP131 or SPI20 were given injection with MTP131 or SPI 20 (3 mg/kg) by peritoneal cavity for 3 times. Blood, urine and renal tissue samples were prepared to determine biochemical parameters. The renal pathological changes were evaluated by hematoxylin and eosin staining and scored semiquantitatively, The protein expression of renal NOX4 was also measured by Western blotting. RESULTS: In diatrizoate-injected rats, Serum creatinine (Scr), fractional excretion of sodium (FeNa%), fractional excretion of potassium (FeK%), pathological scores, renal malondialdehyde (MDA) content, the NADPH oxidase activity and the expression of NOX4 in kidney tissue were significantly increased (p < 0.01). In the groups pretreated with MTP131 or SPI20, the levels of Scr, FeNa%, FeK%, MDA content and NADPH oxidase activity in renal tissue decreased (p < 0.01), the levels of renal super oxygen dehydrogenises and ATPase activity increased (p < 0.01). The renal injuries induced by contrast media (CM) were alleviated. CONCLUSION: MTP131 and SPI20 might protect acute kidney injury induced by CM in rats with hypercholesterolemia.

Effects of electro-acupuncture on endothelium-derived endothelin-1 and endothelial nitric oxide synthase of rats with hypoxia-induced pulmonary hypertension.

Pulmonary hypertension (PH) is characterized by elevated pulmonary artery pressure (PAP), pulmonary vascular remodeling and right ventricular hypertrophy, which are mainly due to endothelial dysfunction. Electro-acupuncture has shown beneficial effects on cardiovascular homeostasis, but little evidence has been obtained on pulmonary effects. The goal of the present study was to investigate whether electro-acupuncture on bladder-13 and -15 points can protect against chronic hypoxia-induced PH by regulating endothelium-derived endothelin (ET)-1 and endothelial nitric oxide synthase (eNOS). Male Wistar rats were exposed to hypoxia to induce PH. Hemodynamic analysis revealed that mean PAP was similar under normoxic conditions. Chronic hypoxia increased mean PAP to 37 +/- 3 mmHg, and electro-acupuncture attenuated it to 29 +/- 3 mmHg. Absolute right ventricular weight was ameliorated by electro-acupuncture from 0.288 +/- 0.048 g to 0.228 +/- 0.029 g under hypoxic conditions. Hypoxia-induced right ventricular hypertrophy index decreased from 0.477 +/- 0.069 to 0.378 +/- 0.053 with electro-acupuncture treatment. Histological examination revealed that hypoxic rats showed increased medial pulmonary artery wall thickness as well as muscularization. However, these alternations by chronic hypoxia were attenuated by electro-acupuncture. There was no difference in eNOS or ET-1 between groups under normoxic conditions. Electro-acupuncture treatment significantly improved the circulating eNOS concentration (365.36 +/- 31.51 pg/mL) compared with only hypoxia exposure (247.60 +/- 30.64 pg/mL). In lung homogenate, levels of eNOS under hypoxia increased from 684.96 +/- 117.90 to 869.86 +/- 197.61 pg/mg by electro-acupuncture treatment. Levels of ET-1 changed oppositely to eNOS in response to electro-acupuncture (ET-1 in plasma, 29.44 +/- 2.09 versus 20.70 +/- 2.37 pg/mL; ET-1 in lung homogenate, 120.51 +/- 3.03 versus 110.60 +/- 4.04 pg/mg). In conclusion, these results indicated that treatment with electro-acupuncture can protect against hypoxia-induced PH, possibly by regulating the balance of endothelium-derived vasoconstrictors and vasodilators.

The synergistic anti-asthmatic effects of glycyrrhizin and salbutamol.

AIM: To investigate the efficacy of glycyrrhizin (GL) combined with salbutamol (SA) as an anti-asthma therapy. METHODS: Rat lung beta2-adrenergic receptor (beta(2)-AR) mRNA level was measured by real-time RT PCR. Intracellular cAMP accumulation was evaluated with a reporter gene assay. An in vitro acetylcholine-induced guinea pig tracheal strip contraction model was used to test the relaxing effects of GL and SA. The anti-inflammatory effects of GL and SA were tested using tumor necrosis factor-alpha-induced NF-kappaB transcriptional activation reporter assay, I-kappaB Western blotting and interleukin-8 ELISA. An in vivo guinea pig asthma model was used to prove further the synergistic effect of GL and SA. RESULTS: GL (0.3 micromol/L) increased mRNA levels of beta(2)-AR in vivo and the accumulation of cAMP in vitro. The combination of GL and SA also resulted in significant complementary anti-inflammatory effects via inhibition of NF-kappaB activation, degradation of I-kappaB and production of interleukin-8. A significant synergistic effect of the combination was detected both in vitro and in vivo in a guinea pig mode. CONCLUSION: The results demonstrate that GL and SA have synergistic anti-asthmatic effects and offer the possibility of a therapeutic application of GL in combination with beta(2)-AR agonists in the treatment of asthma.