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The tendency to use bioactive peptides has increased in recent decades, and research would be essential for recognizing the therapeutic effects of peptides present in animals or food resource. In this study, the in vivo antioxidant and antihypertensive properties of peptides HL-7 with the sequence of YLYELR and HL-10 with the sequence of AFPYYGHHLG were identified from scorpion venom of H. lepturus were evaluated. To study the in vivo effects of peptides, D-galactose-induced and DOCA salt-induced mice models were used. The results of the antioxidant assay for both peptides showed that the activity of serum and liver catalase (CAT), as well as superoxide dismutase (SOD) enzymes, was significantly decreased in the D-galactose-induced group (NC), while MDA levels were increased in serum and the liver tissue samples (p

Nowadays, cancer has become a pervasive disease in the world. Due to the side effects of chemotherapeutic agents, the use of peptides has been increasingly popular among scientists. The present study aimed to assess the cell toxicity and the change in the expression of Bcl-2, tumor necrosis factor-alpha (TNF-α), and Bax genes in HepG2 cancer cell line treated with peptides HL-7 (YLYELAR) and HL-10 (AFPYYGHHLG) using MTT, western blot and real-time polymerase chain reaction (PCR) analyses. The results showed that HL-7 and HL-10 peptides significantly (p

Solid-phase microextraction (SPME) is an analytical method for microextraction of analytes, in which the analytes bind to the sorbent on the surface of the SPME fiber. Many types of chemical agents are used as sorbent; however, many of these sorbents cause secondary contamination or are not cost-effective. Here, aqueous extract of Ferula gummosa was evaluated as potential source of sorbent for simultaneous microextraction of morphine and codeine. For this purpose, multiwalled carbon nanotubes were carboxylated with H2SO4/HNO3 (3:1) and then functionalized with aqueous extract of F. gummosa. Functionalization was confirmed by Fourier transform infrared and Raman spectroscopy measurements as well as scanning electron microscopy analysis. Porous polypropylene hollow fibers were filled with the functionalized carbon nanotubes (CNTs) and used for analyte extraction in urine sample at 40°C and pH 6 for 2 min. Reversed-phase high-performance liquid chromatography (RP-HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that the fiber could preconcentrate 1 ng/mL of morphine and 0.75 ng/mL codeine in urine sample and was successfully used for 30 times with no significant loss in the extraction efficiency. Limit of detection (LOD) and limit of quantification (LOQ) for morphine were 1 and 3.3 ng/mL, respectively. LOD and LOQ for codeine were determined 0.75 and 2.47 ng/mL, respectively. Recovery of the fiber was 80% and 93% for morphine and codeine, respectively. SPME fiber using extract of F. gummosa plant was used for the detection of a small amount of morphine in urine sample. Therefore, plants can be considered as abundant and cheap sources of sorbent for various analytical purposes.

In the study, the impact of protonectin (IL-12) on the bioavailability of human lung carcinoma cell line A549 as well as on HFLF healthy lung fibroblast cells was investigated for 24 h and 48 h. Results demonstrated highest cytotoxicity of protonectin on the A549 cell line at 12 µg/ml and 50 µg/ml, and after 48 h and 24 h cell incubation respectively. No cytotoxicity was observed during the incubation of normal HFLF lung cells with the IL-12 peptide. The peptide did not have any significant impact on the hemolysis of human and cattle red blood cells as well as on the viability of human lymphocytes. The effect of protonectin on gene expression of BMI-1 and CD44 as cancer markers was investigated by the real-time RT-PCR. Results indicated that the effect of the peptide on down-regulation of the BMI-1 gene expression was higher compared to CD44 at 12 µg/ml over 24 h and 48 h. A dose and time-dependent pattern was observed in the production of reactive oxygen species (ROS) in the treated A549 cells. From this study, it can be concluded that protonectin has a significant impact on cancer cells for the down-regulation of gene expression of cancer markers and for the up-regulation of the production of ROS.

This study is aimed at extracting and purifying bioactive peptides from white grub larvae (Polyphylla adspersa) hydrolysate and examining their antioxidant effects on lung cancer cells (A549). Bioactive peptides from white grub larvae hydrolysate (WGLH) were produced using papain, pancreatin, proteinase-K and trypsin. The results showed that papain hydrolysate had the most 1, 1-diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging. This hydrolysate was fractionated by reverse-phase liquid chromatography (HPLC) and two most antioxidant fractions were identified by tandem mass spectrometry that had the sequence of YPQSLRWRAK (1304.6 Da, hereby called YK-10) and LPLFFYDVRP (1266.6 Da, hereby called LP-10). Cytotoxicity effect of YK-10 and LP-10 peptides on A549 cells, human umbilical vein endothelial cells (HUVECs) and human red blood cells were examined. The two peptides induced the specific activity of catalase, superoxide dismutase, glutathione peroxidase, and total level of thiol in A549 cells. Reactive oxygen species in treated A549 cells were significantly lower than that of controls. In conclusion, our results suggest that YK-10 and LP-10 peptides from WGLH have antioxidant activities and can protect A549 cells against free radicals’ damages.

A novel beta-1,4-glucanase was purified and characterized from symbiotic Bacillus sp. CF96 of termite. The SDS-PAGE and zymogram analyses revealed a molecular mass of 35.6 kDa. Optimal activity was at 50 °C and pH 5.5, while the enzyme was active over a wide range of temperature 20–80 °C and pH 4–10 and interestingly more than 60% of the maximum activity remained up to pH 9. The enzyme activity increased in the presence of hexane, chloroform and methanol (20% v/v). while, the enzyme activity was inhibited by metal ions such as Mn2+, Hg2+, Cu2+, Zn2+, Mg2+, Fe2+. The isolated enzyme was able to degrade carboxymethyl cellulose (CMC), avicel and cellulose. Cellobiose was the hydrolytic product of enzymatic reaction based on thin layer chromatography (TLC) analysis. Regarding beta-1,4 endo/exoglucanase activity and high temperature, pH and solvent stability, the enzyme has potential for various industrial applications especially in designing pesticide for termite.

The ability of extraction and preconcentration of small amounts of substances from biological samples is very important in medical toxicology. On the other hand, minimal use of organic solvents is an important issue to prevent environmental damage. In the present study, we developed a new solid phase microextraction fiber using plant extracts as sorbent for extraction and preconcentration of morphine in urine sample. For this purpose, raw carbon nanotubes (CNTs) were functionalized with tobacco extracts. Functionalization was confirmed by Fourier transform infrared (FTIR) and Raman spectroscopy in addition to scanning electron microscope (SEM) images. The functionalized CNTs were coated on polypropylene hollow fiber. The results of HPLC analysis showed that the produced fiber could preconcentrate a very low concentration of morphine (0.25 ng/ml) in small volume of urine samples. Limit of detection (LOD) and limit of quantification (LOQ) for the produced fiber were determined 0.25 ng/ml and 0.825 ng/ml, respectively, and recovery of the fiber was determined 89% at LOQ. The produced fiber provided a recyclable and solvent free method for extraction of a trace amount of morphine, which can be successfully used for up to 30 times with no significant loss in the extraction efficiency.

In this study, the effect of peptides HL-7 and HL-10 was examined on human breast cancer cells (MCF-7 cell line) in the presence and absence of H2O2 and the results were compared with glutathione (GSH) served as a positive control. The results showed that the peptides showed dose-dependent cytotoxicity (P

Antioxidant enzymes protect cells against reactive oxygen species. The level of antioxidant enzymes is reduced almost in cancer cells. The effect of brevinine-2R (B2R) peptide on antioxidant enzyme activities in A549 cell line were investigated and results compared with glutathione (GSH). Catalase, superoxide dismutase (SOD) and glutathione peroxidase of A549 extract cells had their most activities in treated cells at 4.8 µM of B2R and 9.5 µM of GSH for 24 h. Cell attachment was also increased in the presence of B2R and GSH peptide. Thiol status, antioxidant capacity and reactive oxygen species (ROS) of the treated A549 cells were measured. B2R showed its most ROS level, antioxidant capacity and thiol status in the treated cells at 4.8 µM of peptide. B2R peptide like GSH has cytoprotective effect on A549 cells by strengthening the cellular antioxidant system thereby confirming potential pharmaceutical property of the peptide.

Background and Aim: Renal transplantation is one of the main treatments of chronic renal disease that creates a more optimal condition and reduces the risk of fatality. The most common reason behind the functional problems of transplanted kidney in its initial postoperation phase is acute renal transplant rejection, the timely diagnosis of which would help the doctors, begin the required treatments immediately to maintain renal functionality, and prevent further irrecoverable damages. Therefore, identifying the variables which are accurate and reliable predictors of renal transplant rejection can be hugely beneficial. Materials and Methods: In this historical cohort study, 87 nondiabetic patients with renal failure who had received treatments at Kidney Transplantation Department of Imam Reza and Ghaem Hospitals of Mashhad, Iran, were selected and their demographic and clinical characteristics were collected. Among these data, creatinine, fasting blood sugar (FBS) and serum insulin, thyroid-stimulating hormone (TSH), and T3 and T4 hormones were measured four times after the transplant operation. Data were analyzed using SAS 9.3 and MedCalc 13 software. First, the missing data were imputed with appropriate imputation methods, and then using logistic regression and area under receiver operating characteristic (ROC) curve, the most important detectors of acute renal transplant rejection were determined. Significance level (α) was set at 0.01. Results: Using logistic regression analysis and drawing ROC curves for average value of four measurements, the effect of serum creatinine and T4 hormone was found statistically significant (P < 0.01). Conclusion: Results showed that among six variables that were studied (creatinine, FBS, insulin, TSH, T3, and T4), serum creatinine and T4 hormone were statistically significant and also were the most important of acute renal transplant rejection.

In this study, the scorpion venom of H. lepturus was fractionized by reversed phase high-pressure liquid chromatography (RP-HPLC). The sequences of two peptide fractions were identified by tandem mass spectrometry and named as HL-10 (AFPYYGHHLG) and HL-7 (YLYELAR), respectively. Antioxidant activity and cellular effect of synthetic peptides on A549 cell line were investigated. Results showed that the two peptides had high activities in radical scavenging and inhibition of lipid peroxidation in a concentration-dependent manner. The HL-10 and HL-7 peptides demonstrated cytotoxicity on A549 without any hemolytic effect. By increasing of peptide concentrations induced significantly (P ≤ 0.01) activities of catalase and glutathione peroxidase. Our results showed that HL-7 peptide had higher antioxidant potency, whereas the HL-10 peptide revealed a great cytotoxicity on A549 cell line by MTT assay. Our results suggested that the peptides of H. lepturus, possessed free radicals scavenging likewise increased antioxidant enzyme activities in A549 cells.

Hollander, DB, Worley, JR, Asoodeh, M, Wakesa, D, Magnuson, M, Dantzler, DK, Didier, JJ, and Kraemer, RR. Comparison of resistance exercise perceived exertion and muscle activation at varied submaximal durations, loads, and muscle actions. J Strength Cond Res 31(5): 1387-1394, 2017-Previous studies investigating muscle activation from dynamic, plate-loaded, concentric (CON) and eccentric (ECC) muscle contractions have not accounted for the greater absolute strength of ECC contractions. The purpose of the study was to determine the effect of different dynamic muscle contraction durations, loads, and contraction types (CON and ECC) on perceived exertion and muscle activation differences in 6 women (mean ± SD age, height, weight, body mass index 22.83 ± 2.56 years, 1.65 ± 0.261 m, 68.56 ± 2.72 kg, 25.26 ± 4.39 kg·m). The participants were recruited and trained to move weight at the appropriate duration (2, 3, 4, and 5 seconds) for leg extension using a displacement apparatus (sonic emitter, auditory) and a computer program (visual feedback of bar displacement). Concentric and ECC 1 repetition maximum (1RM) were determined for leg extension for the midrange 3-second duration. Thirty, 50, and 70% of either CON or ECC 1RM were loaded for the remainder of the sessions. Subjects were then assigned to complete trials in a counterbalanced fashion for load, contraction type, and contraction duration. Rating of perceived exertion (RPE) significantly increased in response to load (30, 50, and 70%) regardless of contraction type as did electromyography (EMG) root mean square amplitude. Greater time under tension significantly increased RPE regardless of contraction type during knee extension exercise. The EMG amplitude was less distinguishable between 2, 3, 4, and 5 seconds of contractions. The data highlight the effort sense distinctions made by women at submaximal exercise loads during knee extension. These findings should be used to develop effective resistance exercise protocols that facilitate positive perceptions and adherence resistance exercise loads, durations of contraction, and contraction type.

Detection of HIV infection is essential for diagnosis and monitoring of the infection. There are different types of diagnostic tools available that are based on detection of HIV-specific antibodies, viral antigen or nucleic acid. Sensitivities and specificities of assays utilized for HIV detection have improved. Newer HIV testing technologies such as third-generation enzyme immunoassay which detect HIV-specific IgG and IgM antibodies, fourth-generation enzyme immunoassay which detect both anti-HIV antibodies and HIV p24 antigen and nucleic acid based tests for HIV RNA have significantly decreased the window period. This review provides an overview of current technologies for the detection and monitoring of HIV infection and recent advances in the field of HIV diagnosis.

Drug resistance is a phenomenon that frequently impairs a proper treatment of infections and cancer with chemotherapy. Multidrug efflux transporters extrude structurally dissimilar organic compounds often providing resistance to multiple toxic chemotherapeutic agents. The quantitative analysis of drug efflux requires measuring the affinity of ligands. In this work, the interaction between cyclophosphamide (Cyc) and estradiol (ES) with human serum albumin (HSA) was studied by fluorescence polarization, circular dichroism and high-performance liquid chromatography (HPLC) under physiological conditions (pH = 7.4). Gradual addition of HSA led to a marked increase in fluorescence polarization. Our assays indicated that the protein was bound to these drugs with different K d. Also, the Hill coefficient showed a simple drug binding process with no cooperativity. Circular dichroism results revealed the occurrence of conformational changes in HSA molecules by the binding of Cyc and ES. The protein binding of the drug was studied by HPLC. Our results indicated that the drug was bound to the protein and that the presence of a second drug affected the interaction and resistance between the first drug and the protein.

In this study, Aspergillus oryzae CH93 was isolated from soil sample and examined using molecular analysis. Following culture of A. oryzae CH93 under optimal enzyme production, a 47.5kDa extracellular protease was purified using ammonium sulfate precipitation and Q-Sepharose chromatography. The optimal pH 8 and temperature of 50°C obtained for the isolated protease. Sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide (CTAB), H2O2 decreased activity, while Triton X-100 and phenylmethanesulfonyl fluoride (PMSF) had no inhibitory effect on the enzyme activity; meanwhile, 2-mercaptoethanol and ethylenediaminetetraacetic acid (EDTA) declined the protease activity. Isoamyl alcohol and acetone (30%) enhanced activity whereas 2-propanol, isopropanol and dimethyl sulfoxide (DMSO) (30%) reduced protease activity. The enzyme exhibited a half-life of 100min at its optimum temperature. Among five substrates of bovine serum albumin (BSA), N-acetyl-l-tyrosine ethyl ester monohydrate (ATEE), casein, azocasein and gelatin results showed that casein is the best substrate with Vmax of 0.1411±0.004μg/min and Km of 2.432±0.266μg/ml. In conclusion, the extracted protease from A. oryzae CH93 as a fungal source possessed biochemical features which could be useful in some application usages.

The present study was carried out to characterize Angiotensin-converting enzyme (ACE) inhibitory peptides which are released from the trypsin hydrolysate of wheat gluten protein. The binding of two inhibitory peptide (P4 and P6) to human serum albumin (HSA) under physiological conditions has been investigated by multi-spectroscopic in combination with molecular modeling techniques. Time-resolved and quenching fluorescence spectroscopies results revealed that the quenching of HSA fluorescence by P4 and P6 in the binary and ternary systems caused HSA-peptides complexes formation. The results indicated that both peptides quenched the fluorescence intensity of HSA through a static mechanism. The binding affinities and number of binding sites were obtained for the HSA-peptides complexes. The circular dichroism (CD) data revealed that the presence of both peptides increased the α-helix content of HSA and induced the remarkable folding of the polypeptide of the protein. Therefore, the CD data determined that the protein structure has been stabilized in the percent of ACE inhibitory peptides in binary and ternary systems. The binding distances between HSA and both peptides were estimated by the Forster theory, and it was revealed that nonradiative energy transfer from HSA to peptides occurred with a high probability. ITC experiments reveal that, in the absence and presence of P6, the dominant forces are electrostatic in binary and ternary systems. Furthermore, molecular modeling studies confirmed the experimental results. Molecular modeling investigation suggested that P4 bound to the site IA and IIA of HSA in binary and ternary systems, respectively. This study on the interaction of peptides with HSA should prove helpful for realizing the distribution and transportation of food compliments and drugs in vivo, elucidating the action mechanism and dynamics of food compliments and drugs at the molecular level. It should moreover be of great use for understanding the pharmacokinetic and pharmacodynamic mechanism of the food compliments and drugs.

This research was conducted to investigate the biochemical effects of thymosin alpha-1 using human lung cancer cells (A549). The A549 cells were treated with different concentrations of Thα1 for 24 h and the growth, inhibition of cells was determined. Thα1 revealed anti-proliferative effect at 24 and 48 μg/ml after 24 h. Furthermore, it indicated antioxidant properties by significantly enhancing the activity of catalase (12 μg/ml), superoxide dismutase (6 and 12 μg/ml), and glutathione peroxidase (3, 6 and 12 μg/ml) and reducing the production of cellular ROS. Our results showed that Thα1 inhibits the migration of A549 cells in a concentration-dependent manner after 24 and 48 h. Moreover, the effect of Thα1 on apoptosis was investigated by Hoechst 33342 staining and cell cycle analysis. Results demonstrated no significant effect on the induction of apoptosis in A549 cells. In conclusion, our results showed the antioxidant properties of Thα1 on A549 cancer cells.

In this research, the antioxidant property of thymosin alpha-1 (Thα1) peptide was investigated through various antioxidant methods. Thα1 showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50 = 20 µM) and its 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging reached 45.33% at 80 µM (IC50 = 85 µM). In addition, hydroxyl and superoxide radical scavenging of Thα1 peptide exhibited a concentration-depended manner. The IC50 values of hydroxyl and superoxide radical scavenging were estimated to be 82 µM and 20 µM, respectively. The effect of Thα1 on eliminating superoxide radicals was higher (62.23%) than other antioxidant assays. Moreover, the antioxidant activity of Thα1 peptide was evaluated by measuring cellular reactive oxygen species (ROS). Results indicated that Thα1 decreased the generation of ROS level in 1321 N1 human neural asterocytoma cells. The inhibitory effect of Thα1 on angiotensin-converting enzyme (ACE) was determined. The kinetic parameters (Km and Vmax) and the inhibition pattern were examined. Based on the Lineweaver-Burk plot, Thα1 displayed a mixed inhibition pattern. The IC50 and Ki values of Thα1 were 0.8 µM and 3.33 µM, respectively. Molecular modeling suggested that Thα1 binds to ACE-domains with higher affinity binding to N-domain with the binding energy of −22.87 kcal/mol. Molecular docking indicated that Thα1 interacted with ACE enzyme (N- and C-domains) due to electrostatic, hydrophobic, and hydrogen forces. Our findings suggested that Thα1 possess a multifunctional peptide with dual antioxidant and ACE-inhibitory properties. Further researches are needed to investigate the antioxidant and anti-hypertensive effect of Thα1 both in vitro and in vivo.

In this study, we examined cytotoxic effect of GL-9 peptide on A459 cell line through studying the changes in TNF-α and CD44 gene expression and ROS production. Real-time PCR analysis showed that the treated A549 cells highly over expressed TNF-α, which was associated with a significant reduction of CD44 gene expression levels (p

In the present study, an endo -1-4-glucanase was isolated from Bacillus subtilis DR8806. The enzyme was purified to homogeneity via salt precipitation and ion-exchange chromatography. SDS-PAGE analysis revealed a molecular mass of 52 kDa. Optimum pH of enzyme was 9.5 and the enzyme was stable at pH range of 8.5–10.5. The optimum temperature of enzyme was found to be 55 °C and it showed a remarkable stability at temperatures between 40 and 60 °C. The enzyme activity was stimulated by Co 2+ , K + , Mg 2+ , Ca 2+ and Na + ions while Hg 2+ , Mn 2+ , Pb 2+ and Zn 2+ ions were found to inhibit the enzyme activity. The enzyme activity was decreased by increasing in concentration of β-mercaptoethanol, EDTA, SDS, PMSF and Triton X-100. Organic solvents such as hexane, 2-propanol, acetone and ethanol (20% v/v) stimulated enzyme activity by 110%, 114%, 119% and 128%, respectively. Imidazolium-based ionic liquids (ILs) had inhibitory effects on endo -1-4-glucanase activity. Using carboxymethyl cellulose as substrate, kinetic parameters of K m apparent and V max were calculated to be 1.49% (W/V) and 66.66 μM min −1 mg −1 , respectively. Endo -1-4-glucanase coding gene of B. subtilis DR8806 was identified by T/A cloning. The computational modeling of endo -1-4-glucanase showed that two Glu residues are at active site. Our results suggest that the enzyme has great of potential applications in hydrolyzing cellulosic substrates.

A peptide from ostrich ( Struthio camelus ) egg white protein hydrolysate (OEWPH) was purified, characterized, and its antioxidant and enzyme inhibitory properties were evaluated. The OEWPH was prepared using pepsin and pancreatin, and then fractionated using reversed-phase high performance liquid chromatography. The antioxidant activity of the WG-9 peptide was investigated based on its scavenging capacity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,20-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), superoxide (O 2 •− ), hydroxyl (OH •− ), and lipid peroxidation inhibition. The angiotensin-converting enzyme (ACE) inhibitory activity and kinetic parameters of the peptide were determined using N-[3-(2-Furyl)acryloyl]-L-phenylalanyl-glycyl-glycine (FAPGG) as a substrate. Tandem mass spectrometry analysis of the purified peptide revealed a sequence of WESLSRLLG (MW: 1060 Da; WG-9). This peptide inhibited linoleic acid oxidation and acted as a DPPH (IC 50 = 15 ± 0.4 μg/mL), ABTS (IC 50 = 130 ± 4.5 μg/mL), superoxide (IC 50 = 160 ± 6.4 μg/mL), and hydroxyl (IC 50 = 150 ± 6.7 μg/mL) radical scavenger. The ACE-inhibitory activity and kinetic parameters of the WG-9 peptide were determined, showing an ACE inhibitory activity with IC 50 of 46.7 ± 1.4 μg/mL. The parameters of peptide/ACE interactions were investigated by molecule docking. Furthermore, viability assays showed that the identified peptide had no cytotoxicity against an HFLF-PI-5 cell line. In conclusion, the WG-9 peptide showed potent antioxidant and ACE-inhibitory activity.

Typically, antimicrobial peptides (AMPs) are short positive charged peptides serving a key role in innate immunity as well as antimicrobial activity. Discovering novel therapeutic agents is considered as an undeniable demand due to increasing microbial species with antibiotic resistance. In this direction, the unique ability of AMPs to modulate immune responses highlighted them as novel drug candidates in the field of microbiology. Patients affected by leishmaniasis; a neglected tropical disease, confront serious problems for their treatment including resistance to common drugs as well as toxicity and high cost of therapy. So, there is a need for development of new drug candidates to control the diseases. Jellein, a peptide derived from royal jelly of honeybee has been shown to have promising effect against several bacterial and fungal species. In current study, anti-leishmanial effect of Jellein and its lauric acid conjugated form was investigated against two forms of Leishmania major (L. major) parasite. Moreover, cytotoxic effect of these peptides was studied in THP1 cell line and human Red Blood Cells (RBCs). Furthermore, the mechanism of action of peptides on L. major promastigotes was assessed through different methods. The results demonstrated that, conjugation of lauric acid to Jellein not only had no effect on the elevation of antimicrobial activity but also halted it completely. Moreover, Jellein caused a limitation in the number of L. major promastigotes by pore formation as well as changing the membrane potential rather than induction of apoptosis or activation of caspases.

Background The aim of this study was to evaluate the effectiveness of topical sucralfate in the management of pressure ulcer (PU) in hospitalized patients. Methods Forty hospitalized patients with stage II PU were included in this prospective, double-blind, randomized, placebo-controlled trial and were randomly divided into 2 groups receiving either sucralfate gel or placebo, on a daily basis. The patients were visited every day for 14 days, the ulcer was evaluated using the Pressure Ulcer Scale for Healing (PUSH) and changes to the measured scores over time were used as an indicator of wound healing. Results There were no statistically significant differences in any of the demographic characteristics between both groups. Both of the interventions reduced the average PUSH score, and at the end of the trial, all but 2 patients were healed. One in each group discontinued the trial because of exacerbation of the ulcer. No significant between-group difference in the average PUSH score reduction was observed (6.36 ± 2.11 vs. 5.89 ± 1.41, P = 0.42). Although the average healing time was less in the sucralfate group (6.05 ± 2.17 vs. 7.78 ± 3.42), the difference was not statistically significant (P = 0.07). Conclusions Sucralfate gel does not improve healing of PU compared with placebo.

Camel milk has high levels of antioxidant peptides; therefore has a significant role in nutrition and health. There is a wide range of diseases associated with oxidative stress in the body, thereby preventing the production of free radicals followed the occurrence of such reactions have an important role in human health. Some peptides derived from natural sources as natural antioxidants have a significant role in the inhibition of free radicals. The aim of this study was the identification and purification of camel milk proteins and evaluation of their antioxidant properties. For this purpose, camel milk proteins were hydrolyzed and examined the antioxidant properties of resulting peptides. Ultrafiltration and reverse-phase HPLC techniques were used for fractionation of the hydrolysate. Antioxidant activity of peptides were evaluated using different methods such as 2,2′-diphenyl-1-picrylhydrazyl (DPPH·), 2,2′-azinobis(3-ethylbenzothiazo-line-6-sulfonic acid) diammonium salt (ABTS+), superoxide (O2·−), hydroxyl (OH·−) and polyunsaturated fatty acid peroxidation assays. The real-time PCR was performed to evaluate changes in expression of superoxide dismutase gene (SOD) as an antioxidant enzyme in HepG2 cells treated with different concentrations of peptide. Active peaks were analyzed using tandem mass spectrometry and thus identified two peptides NEDNHPGALGEPV (NV-13) and KVLPVPQQMVPYPRQ (KQ-15) with 1348.38 and 1780.15 dalton molecular weight, respectively. Both peptides showed antioxidant effects but KQ-15 peptide showed stronger effects than other. Molecular analysis showed that KQ-15 peptide was also able to increase the expression of SOD gene. The results show that the NV-13 and KQ-15 peptides have a high antioxidant capacity and they can be used to deal with diseases associated with oxidative stress.

Antimicrobial peptides are evolutionary components of the immune system generated in response to microbial infections. Human catestatin CgA352–372 (SL-21) is an endogenous neuropeptide with multiple biological functions. The present study aimed to further evaluate the immunomodulatory role of SL-21 in innate immunity of lung cells and investigate its impact on the expression level of pro-inflammatory factors. SL-21 neuropeptide, generated from the C-terminus of chromogranin A, was first chemically synthesized by solid-phase method and purified using C8 semi-preparative RP-HPLC. According to the results of MTT assay, SL-21 showed no significant cytotoxicity effect on human lung epithelial adenocarcinoma cell line (A549) and human fetal lung fibroblast primary cells even at high concentration (

The production of an extracellular htrA-like serine protease by Bacillus subtilis DR8806 was studied in this study. The enzyme was purified using ammonium sulphate precipitation and Sephacryl S-200 size exclusion chromatography. The analysis by SDS-PAGE and zymogram of enzyme showed a molecular weight of 37 kDa. Isoelectric focusing revealed a p I value of 6.6 for the enzyme. By the use of casein as substrate, the enzyme was active and stable at the wide range of temperatures with maximum activity at 45 °C and pH 8. The enzyme activity was increased by Ca 2+ , K + , Mg 2+ , Fe 2+ , dimethylsulfoxide (DMSO), whereas its activity was decreased by Hg 2+ , Ba 2+ , Cu 2+ , Zn 2+ , H 2 O 2 , CTAB (cetyltrimethylammonium bromide) and SDS (sodium dodecyl sulphate). In addition, Mn 2+ , Na + , Triton X-100, β-mercaptoethanol, EDTA (ethylenediaminetetraacetic acid) had no significant effect on the enzyme activity. Among organic solvents, ethanol and methanol enhanced the activity. The gene of the protease showed a 1200 bp open reading frame with 97% similarity to other htrA-like proteases. The computational modeling of the protease showed two distinct domains: a PDZ domain and protease core domain. The catalytic triad also demonstrated a degree of discrepancy in comparison to other serine proteases. It is composed of a serine residue as a nucleophile and a proline as a base center, while the acidic center was not fully identified. The obtained results suggested a new type of htrA-like protease with no previous records in bacillaceae family.

Ostrich (Struthio camelus) egg possesses a high amount of food proteins and thus plays an important role in nutrition.Ostrich egg white proteins were hydrolyzed with pepsin and pancreatin to examine its antioxidant properties and further characterized the most active peptide.Ostrich egg white protein hydrolysate (OEWPH) was fractionized using reversed phase high-pressure liquid chromatography (HPLC). The antioxidant activity of OEWPH and its HPLC fraction were investigated based on their scavenging capacity1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), superoxide ([Formula: see text]), hydroxyl (OH(•-)) radicals, and Cu(+2) chelating. In a wound healing assay, paravertebral excision (1 cm diameter) was made on the skin and the percentage of wound closure was measured at defined intervals (0, 3, 7, and 14 d).A potent antioxidant peptide named DG-10 with the sequence DAESLSRLLG (MW: 1060.18 ± 0.5 Da) was identified from OEWPH. The peptide DG-10 showed DPPH (IC50 = 0.0085 mg/ml), ABTS(•+) (IC50 = 0.56 mg/ml), superoxide (IC50 = 0.36 mg/ml), and hydroxyl (IC50 = 0.4 mg/ml) radical scavenger and copper chelating activity (IC50 = 0.28 mg/ml). In vitro cultured HFLF-pI 5, the cell model, also revealed that DG-10 could protect HFLF-pI 5 cells against H2O2-treated necrosis. Ointment composed of DG-10 peptide exhibited wound-healing properties on adult rats (Wistar strain). The percentage of wound closure in peptide-treated group was 98% by day 14.Our results suggested that DG-10 is a natural agent obtained from ostrich egg possessing considerable antioxidant and wound-healing properties.

The objective of the present research is to study the interaction of separate and simultaneous of alprazolam (ALP) and fluoxetine hydrochloride (FLX) with human serum albumin (HSA) in phosphate buffer (pH 7.4) using different kinds of spectroscopic, cyclic voltammetry and molecular modeling techniques. The absorbance spectra of protein, drugs and protein-drug showed complex formation between the drugs and HSA. Fluorescence analysis demonstrated that ALP and FLX could quench the fluorescence spectrum of HSA and demonstrated the conformational change of HSA in the presence of both drugs. Also, fluorescence quenching mechanism of HSA-drug complexes both separately and simultaneously was suggested as static quenching. The analysis of UV absorption data and the fluorescence quenching of HSA in the binary and ternary systems showed that FLX decreased the binding affinity between ALP and HSA. On the contrary, ALP increased the binding affinity of FLX and HSA. The results of synchronous fluorescence and three-dimensional fluorescence spectra indicated that the binding of drugs to HSA would modify the microenvironment around the Trp and Tyr residues and the conformation of HSA. The distances between Trp residue and the binding sites of the drugs were estimated according to the Förster theory, and it was demonstrated that non-radiative energy transfer from HSA to the drugs occurred with a high probability. Moreover, according to CV measurements, the decrease of peak current in the cyclic voltammogram of the both drugs in the presence of HSA revealed that they interacted with albumin and binding constants were calculated for binary systems which were in agreement with the binding constants obtained from UV absorption and fluorescence spectroscopy. The prediction of the best binding sites of ALP and FLX in binary and ternary systems in molecular modeling approach was done using of Gibbs free energy.

Disulfide bonds are among the most important factors related to correct folding of the proteins. Protein disulfide isomerase (PDI) is the enzyme responsible for the correct formation and isomerization of these bonds. It is rarely studied so far and none of them showed industrial properties. In this study, the gene encoding for a putative PDI from Bacillus subtilis DR8806 was identified, cloned and expressed in Escherichia coli . It was encoded a 23.26 kDa protein. The enzyme was purified by GST affinity chromatography with a specific activity of 1227 u/mg. It was active and stable over a wide range of temperature (20–85 °C) and pH (4.5–10) with an optimum at 65 °C and pH 5.5. Its activity was enhanced by Mn 2+ and Co 2+ while Ag + and Zn 2+ decreased it. Some of the known PDI inhibitors such as Tocinoic acid and Bactiracin did not affect its activity. In-silico analysis shows the five amino acids changes in the protein sequence regarding to the consensus sequence of PDIs, have a positive impact toward the protein thermal stability. This was further confirmed by molecular dynamics simulations. By considering the overall results, the enzyme might be a potential candidate for applications in the respective industries.

In this study, the inhibitory effect of Temporin-Ra (FP-14 peptide) on angiotensin converting enzyme (ACE) was evaluated. Inhibition mechanism was investigated by kinetic studies and molecular docking simulation. Lineweaver–Burk plot revealed that Temporin-Ra behaved as a non-competitive ACE inhibitor supported by the docking simulation. The IC50 and Ki values were determined to be 22.19 μM and 36 µg/ml, respectively. Molecular docking simulation showed that Temporin-Ra bound to both of N- and C-domains of ACE by forming hydrogen bonds and electrostatic interactions; Temporin-Ra displayed higher affinity to C-domain than N-domain. Antioxidant activity of Temporin-Ra was examined using different methods. The antioxidant activity of Temporin-Ra (0.2 mg/ml) in the inhibition of linoleic acid autoxidation was evaluated to be 57 %. 1,1-diphenyl-2-picrylhydrazyl and 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt radicals scavenging activities were 60 % at 0.5 mg/ml and 37 % at 0.3 mg/ml, respectively. The hydroxyl radical scavenging of FP-14 peptide at 0.33 mg/ml was 55 %. The results suggest that Temporin-Ra is a multifunctional peptide that could be exploited to develop new anti-hypertension drugs and bio-compatible natural antioxidants.

The present study was carried out to characterize ACE inhibitory peptides which are released from the trypsin hydrolysate of wheat gluten protein. In silico proteolitic digestion of a high molecular weight glutenin subunit was performed. Among the resultant fragments, four peptides were selected for chemical synthesis based on the chemoinformatics studies and docking properties. The ACE inhibitory activity and kinetic parameters of the most important peptides were determined. Molecular docking simulation was also performed to predict the sites on ACE in which these peptides bind and displayed inhibition mechanisms. Two peptide sequences of IPALLKR (P4) and AQQLAAQLPAMCR (P6) showed higher ACE inhibitory activity among peptide collection. The IC 50 values of P6 and P4 were 43 ± 1.3 μM and 68 ± 2.8 μM, respectively. P6 peptide was proved to be a more potent ACE inhibitor than P4 peptide. Lineweaver-Burk plots revealed that P6 and P4 behaved as non-competitive and competitive ACE inhibitors, respectively. The simulations showed that P4 bound to the active site region. Conversely, P6 bound to the N-terminus entrance of substrate tunnel and obstructed the substrate access into the catalytic site. Overall, the results showed that these peptides would be considered as a model for discovering new bio-compatible ACE inhibitors.

Human catestatin CgA352-372 (SL21) is an endogenous neuropeptide with multiple biological functions. The present study aimed to evaluate the antioxidant, antibacterial, cytotoxic, and DNA damage protective effects of SL21 neuropeptide. SL21 neuropeptide generated from the C-terminus of chromogranin A (CgA) was synthesized by solid-phase method. Synthetic peptide was subjected to various in vitro antioxidant assays including the scavenging of 1,1-diphenyl-2-pycryl-hydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(·+) ), and hydroxyl free radicals, metal ion chelation, inhibition of lipid peroxidation, and reducing power. Moreover, protective effect of SL21 on H2 O2 -induced DNA damage was analyzed using pTZ57/RT plasmid. Methylthiazoltetrazolium assay was also performed to study the cytotoxic effect of SL21 neuropeptide on human peripheral blood mononuclear cells. Furthermore, antibacterial and hemolysis assays were conducted. The results demonstrated high activities of SL21 in scavenging free radicals (DPPH, ABTS(·+) , and hydroxyl), chelating of Cu(2+) /Fe(2+) metal ions, reducing power, and inhibition of lipid peroxidation in a concentration-dependent manner. SL21 neuropeptide revealed a protective effect on DNA damage caused by hydroxyl radicals. Interestingly, the peptide exhibited no significant cytotoxicity towards peripheral blood mononuclear cells. Furthermore, SL21 peptide displayed antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa without any hemolytic activity on human red blood cells. Conclusively, the present study established SL21 (catestatin) as a novel antioxidative peptide that could further be investigated for its potential use as a pharmaceutical agent.

The α-amylase gene from Bacillus sp. DR90 was isolated, inserted into pET28a(+) vector and subsequently expressed in Escherichia coli BL21 (DE3) using 1 mM IPTG as an inducer. Recombinant enzyme containing N-terminal His-tag was sufficiently purified via nickel metal affinity chromatography with purification factor of 6.8-fold and specific activity of 4091 U/mg. The molecular mass of α-amylase was estimated to be about 76 kDa by SDS-PAGE. The recombinant enzyme was active in wide ranges of pH and temperature, exhibiting an optimal activity at pH 4 and 75 °C with T 1/2 of 125 min. Amylase activity did not enhance in the presence of calcium ions. Apart from good stability toward SDS, urea, and EDTA, the purified enzyme showed high compatibility with various solid and liquid detergents. Furthermore, results indicated the stability and stimulation of enzyme in the presence of different organic solvents. Following the incubation of amylase with imidazolium-based ionic liquids, maximum remaining activity was observed in [BMIm][Cl]-containing solution. Overall, presenting outstanding properties including high thermostability, Ca 2+ -independency, broad pH and temperature profiles, organic-solvent tolerance as well as excellent stability and compatibility with detergents, the present recombinant α-amylase will be a suitable candidate in industrial fields, particularly in food and detergent industries.

It has been proved that fresh frog skin is efficient in the wound healing process.The purpose of study is to introduce a formulation of frog skin powder for evaluation of wound repair where fresh frog skin is not available.Rana ridibunda (Ranidae) skins were lyophilized, and a powder was prepared. The powder (0.0005 g) was then mixed with ointment (0.0065 g) for treating each wound. Formulation was used on full-thickness wounds on mice (FO group) and compared to positive and negative controls. In order to study the wound healing process, wound contraction, inflammation, number of fibroblast cells, neovascularization and collagen density were evaluated on days 2, 4 and 6 following the injury. Moreover, CFU measurement was performed for the evaluation of wound contamination.Acceleration in wound contraction in the FO group compared to control groups was significant (p 0.001) on days 4 and 6. Results showed that FO treatment considerably decreased inflammatory cells during the study. On day 4, FO treatment was significantly effective in increasing the number of fibroblast cells and collagen density (p 0.01 and p 0.05, respectively). On day 6 the number of fibroblast cells (p 0.001), collagen density (p 0.05) and neovascularization (p 0.05), were higher in the FO group than the control groups. Results of CFU measurement demonstrated significant reduction of wound contamination in FO treated wounds on days 2 (p 0.05) and 4 (p 0.01).Our findings indicated that the pharmaceutical form of frog skin used in this study has considerable healing and antibacterial effects on wounds.

This work reports the purification and biochemical characterization of angiotensin I-converting enzyme (ACE) from ostrich (Struthio camelus) lung. The molecular weight of the purified enzyme was approximately evaluated to be 200 kDa and the maximum enzyme activity was observed at pH 7.5. The enzyme activity was increased by detergents of Triton X-100 (0.01%), cetyltrimethylammonium bromide (CTAB) (0.1 and 1 mM) and sodium dodecyl sulfate (SDS) (0.1 mM), while decreased by Triton X-100 (1% and 10%) and SDS (1 mM and 10 mM). The secondary and tertiary structure and activity of ACE in the absence and presence of trifluoroethanol (TFE) were investigated using circular dichroism, fluorescence quenching and UV–visible spectroscopy, respectively. Our results revealed that TFE stabilizes ACE at low concentrations, while acts as a denaturant at higher concentration (20%). The Km, Kcat and Kcat/Km values of ostrich ACE towards FAPGG were 0.8 × 10−4 M, 59,240 min−1 and 74 × 107 min−1 M−1, respectively. The values of IC50 and Ki for captopril were determined to be 36.5 nM and 16.6 nM, respectively. In conclusion, ostrich lung ACE is a new enzyme which could be employed as a candidate for studying ACE structure and its natural or synthetic inhibitors.

The interactions between cyclophosphamide hydrochloride (CYC) and aspirin (ASA) with human serum albumin (HSA) were investigated by measuring fluorescence anisotropy, poly-dispersity index, and time-resolved fluorescence. Also, isothermal titration calorimetry (ITC) was performed. The fluorescence spectra of the drugs exhibited an appreciable hypsochromic shift along with an enhancement in the fluorescence intensity. The gradual addition of HSA led to a marked increase in fluorescence anisotropy (r), and from this value it is argued that the drugs were located in a restricted environment of the protein. The binding constants for the ASA–HSA and CYC–HSA complexes were found to be 1.27 × 108 and 4.23 × 108 mol·L−1, respectively, as calculated from the relevant fluorescence data. The polydispersity index and size distribution of the protein–drug complex were measured at several concentrations of the drugs by the zeta potential technique, which confirmed the already obtained experimental results. From the analysis of the steady-state and time-resolved fluorescence quenching of the drugs in aqueous solutions in the presence of HSA, it was found that the quenching is static in nature. ITC experiments revealed that, in the absence of drugs, the dominant forces are electrostatic, whereas hydrophobic and weak electrostatic forces became significant in the presence of the drug. The primary binding pattern between the drugs and HSA was interpreted as a combined effect of hydrophobic association and electrostatic interactions.

Summary In this study, antioxidant peptides from goose egg white proteins produced using various enzymes were purified and characterised. Two peptides were named as p14 and p16, showing the highest scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and the highest metal ion chelating activity, respectively. The sequences of p14 and p16 were identified to be STMMEERRMKVY (1560.72 Da) and DVFRELRVQ (1161.62 Da), respectively. The sequence of p14 has a similarity of 75% to ovalbumin from Meleagris gallopavo and the sequence of p16 has a similarity of 67% to ovalbumin from Taeniopygia guttata. IC50 values of p14 and p16 were determined, and results showed that DPPH radical scavenging activity was 81.6 and 205.5 μm, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid)(ABTS) radical scavenging was 88.4 and 153.8 μm, hydroxyl radical scavenging was 85.5 and 116.3 μm and metal ion chelating was 170.6 and 117.9 μm, respectively. The two identified peptides from goose egg white hydrolysates act as potent natural antioxidant agents.

Ostrich egg white (OEW) proteins were hydrolyzed by trypsin to identify inhibitory peptides of angiotensin I-converting enzyme (ACE). The most active hydrolysate was obtained after 4 h of hydrolysis. It was further consecutively fractionized by ultrafiltration membrane and then was separated into nine fractions by reversed-phase high performance liquid chromatography (RP-HPLC). Among the fractions, the F3 fraction with amino acid sequence of Ala–Phe–Lys–Asp–Glu–Asp–Thr–Glu–Glu–Val–Pro–Phe–Arg (MW: 1582.74 Da) and IC50: 80.2 μM exhibited the highest ACE inhibitory activity. Kinetic studies revealed that the F3 peptide acts as a non-competitive inhibitor against ACE. The interaction between the F3 peptide and ACE was further scrutinized by fluorescence spectroscopy and molecular modeling techniques. The binding of the F3 peptide to ACE was observed to occur via two classes of binding sites and F3 had more affinity to N-domain than C-domain. Industrial relevance Angiotensin converting enzyme (ACE) can increase blood pressure by catalyzing the conversion of the inactive angiotensin-Ι to the strong vasoconstrictor angiotensin-ΙΙ. Inhibition of ACE by decreasing the concentration of angiotensin ΙΙ is of great importance. In this study, a thirteen-amino acid peptide was identified from Ostrich egg white (OEW) hydrolysates which can potently inhibit ACE. Thus, the identified peptide could be considered as a worthwhile peptide to control hypertension via using as a supplement for special food products. Furthermore, the results can be used as a model for studying the interaction of inhibitory peptides with ACE.

Ethnopharmacological relevance Study of the interrelationships between human and the animals in their environment has always been a subject of interest and caused discoveries of the animal applications in medicine. From the latest century, these remedies called back in traditional medicine of Vietnam and South America and frog skin was used as a biological dressing and had good effects in healing wounds. Also, frog skin secretions have wound healing properties and reduce inflammation. In this study we applied these secretions in the form of ointment to investigate their healing activities. Materials and methods Skin secretions were extracted from Rana ridibunda to evaluate their effects on wound healing in mice. Secretion used as raw extract (RE) and ultrafiltrated extract, using a membrane with cutoff 10 kDa as under 10 kDa (U10E), was administrated as ointment every 48 h on wound site. Control group was left without any treatment and also there was other group treated with ointment (O group) alone. On 2, 4 and 6 days post injury, animals were euthanized and images were taken for wound closure evaluation. Then wound locations were removed for histological assays. Also wound microbial load was examined. Observational parameters including wound closure and wound microbiology in experimental groups compared with the control and O groups have been studied. Results The results showed U10E group has better effects than RE, O and control groups. Histological parameters, including numbers of inflammatory and fibroblast cells and amount of collagen fibers, neovascularization, as well, represented greater degree of wound healing in U10E group compared with RE, O, and control groups. Conclusions Our results showed that frog skin secretions were significantly effective in promoting wound healing process. The U10E extract from the frog R. ridibunda possesses a potent accelerating wound healing effect that promises good potential for clinical application in wound care. Further studies will be required to characterize special molecules encompassing healing properties.

Background\ud Heat shock protein 27 (HSP27) is an intracellular molecular chaperone that is expressed at high levels following the exposure of cells to environmental stressors such as heat, toxins, and free radicals. High levels of HSP antigens and antibody titers have been reported in several conditions including cardiovascular disease and cancers. We measured serum anti-HSP27 antibody levels in 993 subjects and assessed the associations between serum anti-HSP27 antibody levels and demographic characteristics including coronary risk factors.\ud \ud Methods\ud A total of 993 subjects were recruited as part of the Mashhad Stroke and Heart Atherosclerotic Disorders (MASHAD) cohort study. Demographic, clinical, and biochemical parameters and serum anti-HSP27 antibody titers were determined in all the subjects.\ud \ud Results\ud Serum anti-HSP27 antibody levels increased with increasing age in men. No significant differences in levels were detected between men and women. Serum anti-HSP27 antibody levels were significantly higher in obese subjects than in nonobese subjects (P = 0.046); however, no significant influence of smoking status was observed. Moreover, serum anti-HSP27 antibody titers were positively associated with age, body mass index, waist/hip ratio, the presence of diabetes mellitus, nonsmoking habit, serum triglycerides, cholesterol, and high-sensitivity c-reactive protein.\ud \ud Conclusion\ud We have found that serum anti-HSP27 antibody titers are related to several cardiovascular risk factors, necessitating further studies on the value of this emerging marker for risk stratification.

Peptides from natural sources such as milk are shown to have a wide spectrum of biological activities. In this study, three peptides with antioxidant capacity were identified from camel milk protein hydrolysate. Pepsin and pancreatin were used for hydrolysis of milk proteins. Ultrafiltration and reverse-phase high-performance liquid chromatography were used for the concentration and purification of the hydrolysate, respectively. Sequences of the three peptides, which were determined by matrix-assisted laser desorption/ionization time-of-flight spectrophotometry, were LEEQQQTEDEQQDQL [molecular weight (MW): 1860.85 Da, LL-15], YLEELHRLNAGY (MW: 1477.63 Da, YY-11), and RGLHPVPQ (MW: 903.04 Da, RQ-8). The 3-(4,5-dimethylthia-zol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to evaluate the cytotoxicity of these chemically synthesized peptides against HepG2 cells. In vitro analysis showed antioxidant properties and radical scavenging activities of these peptides on 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)+, O2–, and OH– free radicals. HepG2 cells were treated with YY-11 peptide for 48 hours, and the expression of superoxide dismutase and catalase genes was examined using real-time polymerase chain reaction. The results revealed a significant increase in the expression of superoxide dismutase and catalase genes in treated HepG2 cells.

Human serum albumin (HSA) and holo transferrin (TF) are two serum carrier proteins that are able to interact with each other, thereby altering their binding behavior toward their ligands. During the course of this study, the interaction between HSA–PPIX and TF, in the presence and absence of lomefloxacin (LMF), was for the first time investigated using different spectroscopic and molecular modeling techniques. Fluorescence spectroscopy experiments were performed in order to study conformational changes of proteins. The RLS technique was utilized to investigate the effect of LMF on J-aggregation of PPIX, which is the first report of its kind. Our findings present clear-cut evidence for the alteration of interactions between HSA and TF in the presence of PPIX and changes in drug-binding to HSA and HSA–PPIX complex upon interaction with TF. Moreover, molecular modeling studies suggested that the binding site for LMF became switched in the presence of PPIX, and that LMF bound to the site IIA of HSA. The obtained results should give new insight into research in this field and may cast some light on the dynamics of drugs in biological systems.

Ostrich (Struthio camelus) egg white (OEW) proteins were hydrolyzed using various proteases (α-chymotrypsin, pepsin, trypsin and papain). Antioxidant activities of hydrolysates were evaluated using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and iron chelating activity. The hydrolysate obtained by trypsin exhibited the highest antioxidant activity. This hydrolysate was passed through an ultrafiltration membrane with a 3 kDa-cut off, and the resulting filtrate was purified using reversed-phase high performance liquid chromatography (RP-HPLC). Eight peptide fractions were separated and their antioxidant activities were tested. The results showed that the F6 fraction possessed the highest antioxidant activity in the inhibition of linoleic acid autoxidation (86.4% at 20 μg/ml), scavenging activity for DPPH radical (81% at 200 μg/ml) and 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt (ABTS) radical (37.6% at 90.9 μg/ml). In addition, the iron chelating activity, hydroxyl radical scavenging and reducing power of the F6 fraction were 20% at 317.5 μg/ml, 28.6% at 163.9 μg/ml and 0.083 at 113.6 μg/ml, respectively. The peptide sequence was found to be LTEQESGVPVMK (with a molecular mass of 1317.65 Da) using mass spectrometry. The results suggest that the digestion of OEW proteins by trypsin protease could be exploited to produce natural antioxidants.

Brevinin-2R is an antimicrobial peptide which has been isolated from the skin of the frog Rana ridibunda. The purpose of the present study was to examine the cellular cytotoxicity and inflammatory effects of brevinin-2R (B2R) on human lung epithelial adenocarcinoma cell line A549. The effects of different concentrations (5, 10, and 20 μg/ml) of B2R on the expression levels of pro-inflammatory cytokines such as IL-1β, and IL-8 in A549 cells were evaluated by semi-quantitative RT-PCR and real-time PCR assays in a dose- and time-dependent manner. Based on the results of MTT assay, B2R showed a moderate cytotoxicity effect in a dose-dependent manner up to 20 % suppression of the cell growth. Moreover, gene expression results demonstrated that B2R up-regulates the IL-1β and IL-8 expression levels in A549 cells in a dose- and time-dependent manner. Our results suggested that brevinin-2R antimicrobial peptide has potentially a regulatory effect on triggering the inflammatory processes.

Much research has been focused on antimicrobial peptides (AMPs) derived from insect immune defense reactions due to their potential in the development of new antibiotics. In this study, a new AMP from the insect Paederus dermatitis, named sarcotoxin Pd was identified and purified using gel filtration and reverse-phase high-performance liquid chromatography. Our results showed that this peptide has broad-spectrum inhibitory effects on examined microbes. Sarcotoxin Pd is composed of 34 amino acids and its molecular weight was estimated to be 3613.26 ± 0.5 Da. Minimum inhibitory concentration (MIC) values of sarcotoxin Pd against Gram-negative bacteria were lower than Gram-positive bacteria and fungi. The identified peptide showed the highest antimicrobial effect against Klebsiella pneumonia and Escherichia coli. This peptide did not reveal significant hemolytic activity against human red blood cells particularly in the range of MIC values. Confirming the potential antimicrobial activities of synthetic peptide, this paper addresses the role of sarcotoxin Pd in the treatment of systemic microbial illnesses.

Hen egg white lysozyme (HEWL) was hydrolysed with trypsin, papain and a combination of the two. The prepared hydrolysates exhibited ACE inhibitory activity. The hydrolysates were fractionated using ultrafiltration and reverse phase-high performance liquid chromatography (RP-HPLC). Three fractions, which showed the highest ACE inhibitory activities, were purified by RP-HPLC. They were the F 7 (from papain–trypsin hydrolysate), F 8 (from papain hydrolysate) and F 3 (from trypsin hydrolysate) fractions. The IC 50 values were 0.03, 0.155 and 0.23 mg/ml for F 7 , F 8 and F 3 , respectively. The F 7 fraction was the most potent ACE inhibitor peptide, and was composed of 12 amino acids, Phe-Glu-Ser-Asn-Phe-Asn-Thr-Gln-Ala-Thr-Asn-Arg (MW: 1428.6 Da). Lineweaver–Burk plots suggest that the F 7 peptide acts as an uncompetitive inhibitor against ACE. The kinetic parameters ( K m , V max , and K i ) for the F 7 peptide were measured and compared to the control.