Green synthesis of silver nanoparticles using aqueous extract of saffron(Crocus sativus L.) wastages and its antibacterial activity against six bacteria

Objective: To synthesis silver nanoparticles(Ag NPs) by using extract of saffron(Crocus sativus L.) wastages and to test their antibacterial activity against six bacteria.Methods: In this paper, the synthesis of Ag NPs using aqueous extract of saffron wastage as a green method without any chemical stabilizer and reducer is demonstrated. The synthesized Ag NPs were determined by UV–vis spectrum, high resolution transmission electron microscopy, X-ray diffraction, and Fourier transmission infrared spectroscopy analysis.Results: UV–vis spectrum showed a peak at 450 nm due to excitation of surface plasmon vibrations. Fourier transmission infrared spectroscopy showed that nanoparticles were capped with plant secondary metabolites. X-ray diffraction analysis also demonstrated that the size range of the synthesized nanoparticles was 12–20 nm. Transmission electron microscope image illustrated Ag NPs with spherical shape and an average size of15 nm. The result of antibacterial activities showed that the biosynthesized Ag NPs had an inhibiting activity against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Shigella flexneri and Bacillus subtilis.Conclusions: The biosynthesized Ag NPs showed significant antibacterial effect against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Shigella flexneri and Bacillus subtilis, so, it can be used in biomedical applications.

Inhibition of α/β-K_6P_2W_(18)O_(62)·10H_2O on the Activity of Mushroom Tyrosinase and Its Antimicrobial Effects

Dawson-type phosphotungstic polyoxometalate α/β-K6P2W18O62·10H2O（P2W18） was synthesized and its inhibitory effect on the mushroom tyrosinase was investigated. It could inhibit diphenolase activity of mushroom tyrosinase as an irreversible inhibitor. When the concentration of the enzyme reached 0.0176 mg/mL, the concentration of P2W18 leading to 50% activity lost（IC50） was 0.05 mmol/L for monophenolase and 0.64 mmol/L for diphenolase. In addition, the antimicrobial activity of P2W18 was evaluated by zone of inhibition test. The results show that P2W18 possesses effective antimicrobial ability against Escherichia coli, Bacillus subtilis, yeast, especially Escherichia coli and yeast.

Inhibition of Carcinogen Induced Activity of γ-glutamyl Transpeptidase by CertainDietary Constituents in Mouse Skin

Cancer chemoprevention, a desirable and important facet of biomedical research, provides a practical approach to identify potentially useful inhibitors of cancer development, and offers an opporiunity to study the mechanism of carcinogenesis. During the recent Past a number of compounds have been tested for their anticarcinogenic potential specially constituents of our diet. The enzyme γglutamyl transpeptidase (GGT) which catalyses the transfer of glutamyl groups of peptides to other peptides and amino acid and has been proposed as a marker of cell proliferation and neoplasia. It also serves as a tool to evaluate the carcinogenic and cocarcinogenic potential of environmental toxicants. In the present investigations, CGT activity induced by careinogenic polycyclic aromatic hydmiarbons, viz. 7, 12-dimethylbenz(a) anthracene (DMBA) and benzo(a) pyrene (BaP) was significantly inhibited by diallylsulfide (DAS) and indole-3-carbnol (I3C) in mouse skin. DAS and 13C are constituents of garlic and cruciferous vegetables respectively. A significant iIthibition in GGT levels was also observed in a strong mitogen (12-o-tetradecanoyl phorbol-13-acetate) induced activity in mouse skin by pretreatment with DAS/13C. Therefore these dietary constituents seem to be strong modifiers of chemically induced carcinogenesis

Inhibitory Activities of Sole Cow Urine and Combined Cow Dung/Cow Urine against the Blight Disease of Ribwort (<i>Plantago lanceolata</i>) at the Cistercian Monastery in Mbengwi, Cameroon

Ribwort (Plantago lanceolata) is a small glabrous to pubescent perennial plant that is native to Europe, America, North Africa and Asia. Nowadays, it is cultivated in many countries across the globe, including Cameroon due to its extensive use in livestock and medicine. Unfortunately in Cameroon, however, the plant has been highly infested by blight, reducing its yield and medicinal value. To reduce blight infestation of ribwort and improve plant yields, we aimed to compare the efficacy of sole cow urine and combine cow dung/cow urine to inhibit blight disease caused by Phyllosticta ophiopogonis on ribwort. At the Cistercian Monastery in Mbengwi, Momo Division, Cameroon, we used a Randomized Complete Block Design (RCBD) with 3 Blocks consisting of two treatments (cow dung mixed with cow urine (combine cow dung/urine) and sole cow urine) and one control. After spraying the different blocks of ribworts plants with combined cow dung/urine and sole cow urine at a dosage of 3% concentration, we found an incidence of blight disease of 32.8% and 35.0% on ribworts sprayed with combined cow dung/urine and sole cow urine, respectively, compared to 67.8% in the control. This implies that a mixture of cow dung/cow urine reduces the incidence of blight disease significantly. Furthermore, our pathogenicity test showed that Phyllosticta ophiopogonis (fungus) was responsible for the blight disease. Therefore, to increase ribwort growth, improve adaption and reduce Phyllosticta ophiopogonis fungal infestation in Cameroon, we recommend that the plant should be sprayed with a mixture of cow dung and cow urine at 3% concentration.

Bone morphogenetic protein 2-induced human dental pulp cell differentiation involves p38 mitogen-activated protein kinase-activated canonical WNT pathway

Both bone morphogenetic protein 2（BMP2） and the wingless-type MMTV integration site（WNT）/p-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis.Cross-talk between BMP2 and WNT/p-catenin in osteoblast differentiation and bone formation has been identified.However,the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown.Here,we demonstrate that BMP2 promotes the differentiation of human dental pulp cells（HDPCs） by activating WNT/p-catenin signalling,which is further mediated by p38mitogen-activated protein kinase（MAPK） in vitro.BMP2 stimulation upregulated the expression of p-catenin in HDPCs,which was abolished by SB203580 but not by Noggin or LDN193189.Furthermore,BMP2 enhanced cell differentiation,which was not fully inhibited by Noggin or LDN193189.Instead,SB203580 partially blocked BMP2-induced p-catenin expression and cell differentiation.Taken together,these data suggest a possible mechanism by which the elevation of p-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway,which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation.

Panax notogiseng saponin inhibits ischemia-induced apoptosis by activating PI3K/Akt signal pathway in cardiomyocytes

The panax notoginseng saponin(PNS) had been clinically used for the treatment of cardiovascular diseases and stroke in China.It had been demonstrated that PNS could protect cardiomyocytes from injury induced by ischemi- a,but the underlying molecular mechanisms of this protective effect were still unclear.This study was aimed to investigate the protective effect and molecular mechanisms of PNS on apoptosis in H9c2 cells in vitro and rat myocardial ischemia injury model in vivo.Annexin-V/PI assay shew that PNS could protect H9c2 cells from apoptosis induced by serum, glucose and oxygen deprivation(SGOD) in a dose-dependent manner.However,the anti-apoptotic effect of PNS was reversed by LY294002,a specific PI3K inhibitor.This antiapoptotic effect of PNS was confirmed by JC-1,a specific probe of mitochondrial membrane potential staining.PNS could significantly increase phos-Akt in H9c2 cells by Western blot assays and its effect could be inhibited by LY294002.Furthermore,PNS could improve ischemic-induced left ventricular function as reflected by EF,LVDd and LVDs.PNS could also inhibited cellular apoptosis in myocardial tissues in ischemic rats by TUNEL assay.PNS administration also increased the expression of phos-Akt in rat ischemic myocardial tissues.These results suggested that PNS could protect myocardial cells from apoptosis induced by ischemia in vitro model and in vivo model through activating-PI3K/Akt signal pathway which may be meaningful for further understanding the molecular mechanisms of cardiac protection of PNS.And the results might be useful in treatment of myocardial ischemia in future.

Atorvastatin activates autophagy and promotes neurological function recovery after spinal cord injury

Atorvastatin, a lipid-lowering medication, provides neuroprotective effects, although the precise mechanisms of action remain unclear. Our previous studies confirmed activated autophagy following spinal cord injury, which was conducive to recovery of neurological functions. We hypothesized that atorvastatin could also activate autophagy after spinal cord injury, and subsequently improve recovery of neurological functions. A rat model of spinal cord injury was established based on the Allen method. Atorvastatin（5 mg/kg） was intraperitoneally injected at 1 and 2 days after spinal cord injury. At 7 days post-injury, western blot assay, reverse transcription-polymerase chain reaction, and terminal deoxynucleotidyl transferase-mediated dU TP nick-end labeling（TUNEL） staining results showed increased Beclin-1 and light chain 3B gene and protein expressions in the spinal cord injury ＋ atorvastatin group. Additionally, caspase-9 and caspase-3 expression was decreased, and the number of TUNEL-positive cells was reduced. Compared with the spinal cord injury ＋ saline group, Basso, Beattie, and Bresnahan locomotor rating scale scores significantly increased in the spinal cord injury ＋ atorvastatin group at 14–42 days post-injury. These findings suggest that atorvastatin activated autophagy after spinal cord injury, inhibited apoptosis, and promoted recovery of neurological function.

Inhibition of Micro RNA 219 Expression Protects Synaptic Plasticity via Activating NMDAR1, Ca MKIIγ,and p-CREB after Microwave Radiation

In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimental animal models[1,2].

A Novel Schiff Base Zinc Coordination Compound Inhibits Proliferation and Induces Apoptosis of Human Osteosarcoma Cells

Various kinds of schiff base metal complexes have been proven to induce apoptosis of tumor cells. However,it remains largely unknown whether schiff base zinc complexes induce apoptosis in human cancer cells. Here,we synthesized a novel schiff base zinc coordination compound（SBZCC） and investigated its effects on the growth,proliferation and apoptosis of human osteosarcoma MG-63 cells. A novel SBZCC was synthesized by chemical processes and used to treat MG-63 cells. The cell viability was determined by CCK-8 assay. The cell cycle progression,mitochondrial membrane potential and apoptotic cells were analyzed by flow cytometry. The apoptosis-related proteins levels were determined by immunoblotting. Treatment of MG-63 cells with SBZCC resulted in inhibition of cell proliferation and cell cycle arrest at G1 phase. Moreover,SBZCC significantly reduced the mitochondrial membrane potential and induced apoptosis,accompanied with increased Bax/Bcl-2 and Flas L/Fas expression as well as caspase-3/8/9 cleavage. Our results demonstrated that the synthesized novel SBZCC could inhibit the proliferation and induce apoptosis of MG-63 cells via activating both the mitochondrial and cell death receptor apoptosis pathways,suggesting that SBZCC is a promising agent for the development as anticancer drugs.

The Function and Meaning of Receptor Activator of NF-κB Ligand in Arterial Calcification

Osteoclast-like cells are known to inhibit arterial calcification. Receptor activator of NF-κB ligand（RANKL） is likely to act as an inducer of osteoclast-like cell differentiation. However,several studies have shown that RANKL promotes arterial calcification rather than inhibiting arterial calcification. The present study was conducted in order to investigate and elucidate this paradox. Firstly,RANKL was added into the media,and the monocyte precursor cells were cultured. Morphological observation and Tartrate resistant acid phosphatase（TRAP） staining were used to assess whether RANKL could induce the monocyte precursor cells to differentiate into osteoclast-like cells. During arterial calcification,in vivo and in vitro expression of RANKL and its inhibitor,osteoprotegerin（OPG）,was detected by real-time PCR. The extent of osteoclast-like cell differentiation was also assessed. It was found RANKL could induce osteoclast-like cell differentiation. There was no in vivo or in vitro expression of osteoclast-like cells in the early stage of calcification. At that time,the ratio of RANKL to OPG was very low. In the late stage of calcification,a small amount of osteoclast-like cell expression coincided with a relatively high ratio of RANKL to OPG. According to the results,the ratio of RANKL to OPG was very low during most of the arterial calcification period. This made it possible for OPG to completely inhibit RANKL-induced osteoclast-like cell differentiation. This likely explains why RANKL had the ability to induce osteoclast-like cell differentiation but acted as a promoter of calcification instead.

Osteoclast-derived microRNA-containing exosomes selectively inhibit osteoblast activity

With the support by the National Natural Science Foundation of China and National Basic Research Program of China,the research team led by Prof.Li Yingxian(李英贤)at the State Key Laboratory of Space Medicine Fundamentals and Application,China Astronaut Research and Training Center,discovered that osteoclast-derived microRNA-containing exosomes selectively inhibited osteoblast activity,which was pub-

Comparative evaluation of polysaccharides isolated from Astragalus,oyster mushroom,and yacon as inhibitors of α-glucosidase

The incidence of diabetes has increased considerably, and become the third serious chronic disease following cancer and cardiovascular diseases. Though acarbose, metformin, and 1-deoxynojirimycin have good efficacy for clinical application as hypoglycemic drugs, their expensive costs and some degree of side effects have limited their clinical application. Recently, increasing attention has concentrated on the polysaccharides from natural plant and animal sources for diabetes. In order to illustrate the pharmaceutical activity of polysaccharides as natural hypoglycemic agents, polysaccharides isolated from Astragalus, oyster mushroom, and Yacon were evaluated for their inhibitory effects on α-glucosidase. Polysaccharides were extracted and purified from Astragalus, Oyster mushroom, and Yacon with hot water at 90 °C for 3 h, respectively. The total sugar content of the polysaccharide was determined by the phenol-sulfuric acid method. The α-glucosidase inhibitory activity was measured by the glucose oxidase method. The results exhibited that the inhibitory effects on α-glucosidase were in decreasing order, Astragalus > oyster mushroom > Yacon. The α-glucosidase inhibition percentage of Astragalus polysaccharide and oyster mushroom polysaccharide were over 40% at the polysaccharide concentration of 0.4 mg·mL-1. The IC50 of Astragalus polysaccharide and oyster mushroom polysaccharide were 0.28 and 0.424 mg·mL-1, respectively. The information obtained from this work is beneficial for the use polysaccharides as a dietary supplement for health foods and therapeutics for diabetes.

印度蜂蜜提取物中的酚类化合物的抗氧化活性及α淀粉酶抑制活性研究(英文)

AIM:To evaluate the antioxidant and α-amylase inhibition potential of phenolic compounds in the extracts of Indian honey.METHODS:Phenolic compounds were extracted from Indian honey through column chromatography.The antioxidant poten-tial of extracted phenolic compounds was measured by two different biochemical assays:ferric reducing antioxidant power(FRAP) assay and scavenging activity on 2,2-diphenyl-1-picrylhydrazyl(DPPH) radicals.Moreover,α-amylase inhibition assay of phenolic compounds of honey was also evaluated.RESULTS:The scavenging inhibition rate varied from 86.8% to 78.6% from the highest(6 mg·mL-1) to the lowest(1.5 mg·mL-1) concentration,whereas,reducing power assay varied from 0.89 Abs to 0.19 Abs from the highest to the lowest concentration.Butylated hydroxytoluene(BHT) was used as reference compound for antioxidant assays.α-amylase inhi-bition assay is reported from the phenolic honey extracts for the first time.The inhibition rate for α-amylase varied from 88.8% to 30.5% from the highest(20 μg·mL-1) to the lowest concentration(4 μg·mL-1).CONCLUSION:Honey phenolic extract possessed antioxidant and α-amylase inhibition activity,thus increasing its potential therapeutic property.

Synthesis of novel 1,3-oxazole derivatives with insect growth-inhibiting activities

Straightforward and direct synthesis of 2-substituted-5-oxazolecarbaldehydes was achieved by treating propargylamides with mercury（II）perchlorate as catalyst and ammonium cerium（IV）nitrate as oxidant agent through intramolecular cyclization.These structurally interesting outcomes beneft to synthesize2,5-disubstituted-1,3-oxazoles with armyworm growth regulating activities.

LATS1 K751 acetylation blocks activation of Hippo signalling and switches LATS1 from a tumor suppressor to an oncoprotein

Large tumor suppressor 1(LATS1)is the key kinase controlling activation of Hippo signalling pathway.Post-translational modifications of LATS1 modulate its kinase activity.However,detailed mechanism underlying LATS1 stability and activation remains elusive.Here we report that LATS1 is acetylated by acetyltransferase CBP at K751 and is deacetylated by deacetylases SIRT3 and SIRT4.Acetylation at K751 stabilized LATS1 by decreasing LATS1 ubiquitination and inhibited LATS1 activation by reducing its phosphorylation.Mechanistically,LATS1 acetylation resulted in inhibition of YAP phosphorylation and degradation,leading to increased YAP nucleus translocation and promoted target gene expression.Functionally,LATS1-K751 Q,the acetylation mimic mutant potentiated lung cancer cell migration,invasion and tumor growth,whereas LATS1-K751 R,the acetylation deficient mutant inhibited these functions.Taken together,we demonstrated a previously unidentified post-translational modification of LATS1 that converts LATS1 from a tumor suppressor to a tumor promoter by suppression of Hippo signalling through acetylation of LATS1.

Study of Activation and Inhibition of Certain Metal Ions to Amylase Catalyzed Reaction by Microcalorimetry

With or without activation or inhibition of metal ion,the power-time curves of amylase catalyzed reaction were determined by a 2277 thermal activity monitor (Sweden). The Michaelis constant ( K ),apparent Michaelis constant ( K _m),maximum velocity ( v _m) and apparent maximum velocity ( v _ am ) of amylase catalyzed reaction were obtained using thermokinetic theory and reduced extent method. On the basis of data obtained,the following relationships between K _m and concentration of metal ion ( c ) were established: for inhibitor of Ni 2+ K _m=2.9648×10 -3 -1.3912×10 -4 cR =0.9998for inhibitor of Co 2+ K _m=1.0227×10 -3 +8.2676×10 -6 cR =0.9955for activator of Ca 2+ K _m=1.0630×10 -7 c 2-1.8311×10 -6 c +9.3058×10 -6 R =0.9999for activator of Li + K _m=5.6300×10 -8 c 2-1.5329×10 -6 c +1.2662×10 -5 R =0.9999 The K _m- c relationships show a strenuous inhibitory effect for Ni 2+ and a strenuous active effect for Ca 2+ .

Production of whey protein hydrolyzates and its incorporation into milk

Whey proteins provide an excellent source of low-molecular-weight bioactive peptides with important functional properties and bioactivities like antihypertensive,opioid,and antimicrobial effects.Presence of peptide molecules with lower molecular weight has a great role in food for health promotion.In this investigation,the release of low-molecular-weight peptides from whey protein concentrate was attempted by using enzymatic digestion.The hydrolyzate was then incorporated into milk to obtain enriched milk(EM)with low-molecular-weight peptides.Based on sensory analysis of EM,electrophoretic and RP-HPLC studies,hydrolyzates of 10%protein(degree of hydrolysis 5%;enzyme/substrate E/S,1:50)were finally incorporated into milk at 20%(v/v)to develop an acceptable product enriched with low-molecular-weight peptides.EM had higher protein content,viscosity and emulsifying properties than control milk with 3%fat.It is recommended that EM should not be sterilized as it results in coagulation,but can be safely pasteurized and spray dried without any undesirable effects.Maximum ACE-inhibition activity was obtained in hydrolyzate,followed by EM.This study is expected to boost the opportunity for the dairy industry to venture further into the nutraceutical dairy market.

Inhibition of thrombin by functionalized C_(60)nanoparticles revealed via in vitro assays and in silico studies

The studies on the human toxicity of nanoparticles（NPs） are far behind the rapid development of engineered functionalized NPs. Fullerene has been widely used as drug carrier skeleton due to its reported low risk. However, different from other kinds of NPs, fullerene-based NPs（C_（60） NPs） have been found to have an anticoagulation effect, although the potential target is still unknown. In the study, both experimental and computational methods were adopted to gain mechanistic insight into the modulation of thrombin activity by nine kinds of C_（60） NPs with diverse surface chemistry properties. In vitro enzyme activity assays showed that all tested surface-modified C_（60） NPs exhibited thrombin inhibition ability. Kinetic studies coupled with competitive testing using 3 known inhibitors indicated that six of the C_（60） NPs, of greater hydrophobicity and hydrogen bond（HB） donor acidity or acceptor basicity, acted as competitive inhibitors of thrombin by directly interacting with the active site of thrombin. A simple quantitative nanostructure-activity relationship model relating the surface substituent properties to the inhibition potential was then established for the six competitive inhibitors.Molecular docking analysis revealed that the intermolecular HB interactions were important for the specific binding of C_（60） NPs to the active site canyon, while the additional stability provided by the surface groups through van der Waals interaction also play a key role in the thrombin binding affinity of the NPs. Our results suggest that thrombin is a possible target of the surface-functionalized C_（60） NPs relevant to their anticoagulation effect.