Green and eco-friendly biosynthesis of zinc oxide nanoparticles using Calendula officinalis flower extract: Wound healing potential and antioxidant activity.

This study aimed to produce zinc oxide nanoparticles with Calendula officinalis flower extract (Co-ZnO NPs) using the green synthesis method. In addition, the antioxidant and wound healing potential of synthesized ZnO NPs were evaluated. The absorbance band at 355 nm, which is typical for ZnO NPs, was determined from the UV-Vis absorbance spectrum. The energy-dispersive X-ray spectroscopy (EDS) measurements revealed a high zinc content of 42.90%. The x-ray diffractometer data showed Co-ZnO NPs with an average crystallite size of 17.66 nm. The Co-ZnO NPs did not have apparent cytotoxicity up to 10 µg/mL (IC50 25.96 µg/mL). C. officinalis ZnO NPs showed partial cell migration and percent wound closure (69.1%) compared with control (64.8%). In addition, antioxidant activities of Co-ZnO NPs with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2 diphenyl-1 picrylhydrazil (DPPH) were evaluated and radical scavenging activity of 33.49% and 46.63%, respectively, was determined. These results suggest that C. officinalis extract is an effective reducing agent for the green synthesis of ZnO NPs with significant antioxidant and wound healing potential.

A novel electrochemical glucose biosensor based on a poly (L-aspartic acid)-modified carbon-paste electrode.

A new amperometric biosensor was fabricated by means of electropolymerization of L-aspartic acid on a carbon-paste electrode (CPE) for the bioelectrochemical determination of glucose. The electropolymerization process was conducted via cyclic voltammetry (CV). The modified CPE with poly (L-aspartic acid) (PAA) provided free carboxyl groups so as to immobilize the glucose oxidase (GOx), and further, enhanced the electrocatalytic activity of the hydrogen peroxide (H2O2). The biosensor displayed both good stability and good bioactivity. The sensitivity of the prepared biosensor was 5.3 µA cm-2 mM-1. Its linear range extended from 0.05 mM to 1.0 mM, with the low limit of detection (LOD) being 69.2 µM. The Michaelis-Menten constant was found to be 1.17 mM. Furthermore, the biosensor showed good anti-interference ability in relation to dopamine, uric acid, and ascorbic acid. Taken together, these results demonstrate that PAA/CPE is a promising material for the fabrication of glucose biosensor.

Electrochemical nucleic acid hybridization biosensor based on poly(L-Aspartic acid)-modified electrode for the detection of short oligonucleotide sequences related to hepatitis C virus 1a.

This work describes, for the first time, the fabrication of poly(L-aspartic acid) (PAA) film modified pencil graphite electrode (PGE) for the detection of hepatitis C Virus 1a (HCV1a). The presence of PAA on the electrode surface can provide free carboxyl groups for covalent binding of biomolecules. The PGE surface was first coated with PAA via electropolymerization of the L-aspartic acid, and avidin was subsequently attached to the PAA modified electrode by covalent attachment. Biotinylated HCV1a probes were immobilized on avidin/PAA/PGE via avidin-biotin interaction. The morphology of PAA/PGE was examined using a scanning electron microscope. The hybridization events were monitored with square wave voltammetry using Meldola's blue (MDB). Compared to non-complementary oligonucleotide sequences, when hybridization was carried out between the probe and its synthetic targets or the synthetic polymerase chain reaction analog of HCV1a, the highest MDB signal was observed. The linear range of the biosensor was 12.5 to 100 nM and limit of detection was calculated as 8.7 nM. The biosensor exhibited favorable stability over relatively long-term storage. All these results suggest that PAA-modified electrode can be used to nucleic acid biosensor application and electropolymerization of L-aspartic acid can be considered as a good candidate for the immobilization of biomolecules.

Glucose biosensor based on immobilization of glucose oxidase on a carbon paste electrode modified with microsphere-attached l-glycine.

In the present study, a novel biosensor that is sensitive to glucose was prepared using the microspheres modified with (4-formyl-3-methoxyphenoxymethyl)polystyrene (FMPS) with l-glycine. Polymeric microspheres having Schiff bases were prepared from FMPS using the glycine condensation method. Glucose oxidase enzyme was immobilized onto modified carbon paste electrode by cross-linking with glutaraldehyde. Oxidation of enzymatically produced H2 O2 (+0.5 V vs. Ag/AgCl) was used for determination of glucose. Optimal temperature and pH were found as 50 °C and 8.0, respectively. The glucose biosensor showed a linear working range from 5.0 × 10-4 to 1.0 × 10-2 M, R2 = 0.999. Storage and operational stability of the biosensor were also investigated. The biosensor gave perfect reproducible results after 20 measurements with 3.3% relative standard deviation. It also had good storage stability.

Evaluation of the vasoplegic impact of papaverine in the rat aorta.

OBJECTIVE: To identify the degree of vasoplegic affinity of papaverine to rat thoracic aortas following constriction caused by adrenalin, serotonin and potassium chloride in an in-vitro model. METHODS: The in vitro vasoplegic efficacy of papaverine against adrenalin (10(-5) M), serotonin (5HT) (10(-4) M), and KCI (60 mM) was assessed, using a rat aortic vasospasm model in an organ bath. First, aortic rings were constricted with a submaximal dose of vasoconstrictor agents. The samples were then incubated with papaverine (3 x 10(-4) M) for 20 minutes, followed by readministration of the same vasoconstrictor agents. The first vasospastic response (before papaverine incubation) and the new vasoconstrictor responses (after papaverine incubation) of the vessels were then compared. RESULTS: The vasoplegic effect of vasoconstrictor agents in decreasing order was observed as adrenalin > KCl > 5HT. This different affinity for the vasoplegic effect is considered to be a temporary impact of the drugs and the maximal inhibition of vasoconstriction was detected for the adrenalin receptor. CONCLUSION: The relevance of the macromolecules is responsible for the permanent efficacy of the drugs. Different degrees of vasoconstriction were also obtained after papaverine administration, which suggests that different responses can occur as a result of different stimulation of receptor modulators.

Curcumin and carvacrol mediated photodynamic inactivation with 405†nm light emitting diodes (LEDs) on Salmonella Enteritidis.

Photodynamic inactivation (PDI) has a potential application for food preservation that can minimize food pathogens posing risks to consumer health. This study aimed to evaluate the antibacterial activity of 405 nm light-emitting diodes (LEDs) illumination in the presence of carvacrol and curcumin against Salmonella Enteritidis and S. Enteritidis PT4 at different temperatures (4 °C, 25 °C and 37 °C) and time parameters (15 min, 30 min and 45 min) in the illumination system. Compared to their individual treatment, the decrease in the bacterial population was stronger in bacteria treated with LEDs + carvacrol or LEDs + curcumin. Co-application of carvacrol or curcumin with LEDs at 37 °C showed strong antibacterial activity against both bacteria depending on the application time. Co-application at 37 °C for 45 min completely inhibited the growth of S. Enteritidis. LEDs, curcumin, carvacrol applications alone or LEDs + curcumin, LEDs + carvacrol applications caused a decrease in bacterial population in proportion to the increase in the storage temperature and application times. These results showed that carvacrol or curcumin potentiates LEDs illumination therapy against both bacteria. Future studies on adapting the PDI system to control bacteria in a variety of foods may help develop novel strategies to fight against foodborne bacterial pathogens.

The protective effect of erdosteine on vancomycin-induced pancreatic damage in rats.

OBJECTIVE: The goal of this study was to investigate whether vancomycin (VCM) has a negative effect on pancreatic tissue and to elucidate the role of erdosteine (ERD), an expectorant and an antioxidant agent, on possible VCM-induced pancreas impairment in rats. MATERIALS AND METHODS: A total of 21 male Wistar albino rats were included in this study. All animals were equally divided into three groups as follows: Controls (n = 7), VCM treated group (200 mg/kg twice daily for 7 days intraperitoneally, n = 7) and VCM (200 mg/kg) + ERD treated group (10 mg/kg day orally ERD, n = 7). The first dose of ERD administration was performed 24 h prior to VCM injection and the study was continued for 7 days. At the end of the study, all animals were sacrificed. Blood and pancreas tissue samples were collected. For biochemical analysis, serum amylase, lipase, alkaline phosphatase (ALP), and gamma glutamyl transferase (GGT) activities were measured. For histopathological examination, pancreas tissue samples were investigated under the light microscope. RESULTS: VCM administration has significantly increased the serum amylase, lipase, ALP, and GGT activities, when compared with the controls. VCM + ERD administration significantly decreased the serum lipase, amylase, and GGT activities. There was no statistically significant difference between the VCM + ERD treated group and only VCM treated group by means of serum ALP levels. It has been observed that there was a prominent pancreatic tissue damage in only VCM given group. However, ERD exhibited structural protection against VCM-induced pancreatic damage and this effect was statistically significant. ERD has also obtained a marked reduction in the extent of pancreatic damage. CONCLUSION: Erdosteine may play an important role in the VCM-induced pancreatic damage and may reduce the pancreatic damage both in biochemical and histopathological aspects.

Sequence-specific label-free nucleic acid biosensor for the detection of the hepatitis C virus genotype 1a using a disposable pencil graphite electrode.

In this paper, we demonstrate a simple, sensitive, inexpensive, disposable and label-free electrochemical nucleic acid biosensor for the detection of the hepatitis C virus genotype 1a (HCV1a). The nucleic acid biosensor was designed with the amino-linked inosine-substituted 20-mer probes, which were immobilized onto a disposable pencil graphite electrode (PGE) by covalent linking. The proposed nucleic acid biosensor was linear in the range of 0.05 and 0.75 µM, exhibiting a limit of detection of 54.9 nM. The single-stranded synthetic PCR product analogs of HCV1a were also detected with satisfactory results under optimal conditions, showing the potential application of this biosensor.

A Nucleic Acid Biosensor for Detection of Hepatitis C Virus Genotype 1a Using Poly(L-Glutamic Acid)-Modified Electrode.

An electrochemical nucleic acid biosensor based on label-free DNA detection method was prepared for the first time by using electropolymerized poly(L-glutamic acid)-modified pencil graphite electrode (PGA/PGE) for detection of hepatitis C virus genotype 1a (HCV1a). Inosine-substituted 20-mer probes related to the HCV1a were immobilized onto PGA/PGE surface by covalent linking with the formation of amide bonds. Square wave voltammetry (SWV) was used to monitor the oxidation signal of guanine in the hybridization events, which gave an oxidation peak at +1.05 V. An increase in the oxidation signal of guanine was showed by hybridization of the probe with the complementary DNA. Noncomplementary oligonucleotides were also used to investigate the selectivity of the biosensor. The proposed nucleic acid biosensor was linear in the range of 50 nM to 1.0 µM, exhibiting a limit of detection of 40.6 nM. Finally, single-stranded synthetic PCR product analogues of HCV1a were performed in optimal condition. This PGA-modified nucleic acid sensor is cost-effective and disposable, and besides, it has superior electrocatalytic effect on the oxidation of guanine.

Preparation of carbon paste electrodes including poly(styrene) attached glycine-Pt(IV) for amperometric detection of glucose.

In this study, a novel carbon paste electrode that is sensitive to glucose was prepared using the nanoparticles modified (4-Formyl-3-methoxyphenoxymethyl) with polystyren (FMPS) with L-Glycine-Pt(IV) complexes. Polymeric nanoparticles having Pt(IV) ion were prepared from (4-Formyl-3-methoxyphenoxymethyl) polystyren, glycine and PtCl4 by template method. Glucose oxidase enzyme was immobilized to a modified carbon paste electrode (MCPE) by cross-linking with glutaraldehyde. Determination of glucose was carried out by oxidation of enzymatically produced H2O2 at 0.5 V vs. Ag/AgCl. Effects of pH and temperature were investigated, and optimum parameters were found to be 8.0 and 55°C, respectively. Linear working range of the electrode was 5.0×10(-6)-1.0×10(-3) M, R(2)=0.997. Storage stability and operational stability of the enzyme electrode were also studied. Glucose biosensor gave perfect reproducible results after 10 measurements with 2.3% relative standard deviation. Also, it had good storage stability (gave 53.57% of the initial amperometric response at the end of 33th day).

Effects of short-term hyperglycemia on the vasoconstriction of the aorta.

BACKGROUND/AIM: To investigate vasoconstrictor responses of healthy blood vessels to short-term hyperglycemic conditions such as postprandial hyperglycemia, gestational diabetes mellitus, and steroid-induced diabetes. MATERIALS AND METHODS: Female Wistar rat aorta rings were incubated in normal (11 mM) and high (22 mM and 44 mM) glucose concentrations for 4 h. Responses of vasoconstriction were measured in reaction to serotonin (10-5 M), phenylephrine (10-6 M), and KC1 (60 mM) compared to the ambient condition, including different glucose concentrations. RESULTS: While the responses of vasoconstriction to KC1 were increased in the presence of Krebs' solution with high glucose, no statistically significant changes were observed in the reaction to serotonin and phenylephrine. In addition, malondialdehyde levels were increased in hyperglycemic conditions. CONCLUSION: Short-term hyperglycemia may lead to augmented contractile response in aorta rings through several mechanisms, and our results showed that oxidative stress is probably one of them.

Magnesium and diltiazem relaxes phenylephrine-precontracted rat aortic rings.

Perioperative vasospasm during cardiovascular surgery is a challenging problem. Several vasodilator agents are frequently utilized for its prevention in surgical practice. Magnesium and diltiazem both have known potential vasorelaxant effects. We planned to compare the efficacy of diltiazem and magnesium in relieving phenylephrine-precontracted rat aortic rings. Ten young adult female Wistar albino rats weighing 230-260 g were used in this study. The aortic rings in the organ bath equilibrated and reached their baseline tension. Precontraction was induced by 0.001 mmol/l phenylephrine and cumulative concentration-relaxation curves were obtained by consecutively increasing the addition of either diltiazem (10(-6)-0.1 mmol/l) or magnesium (0.1-10 mmol/l). The mean maximal relaxation responses observed by diltiazem and magnesium on separate aortic rings were 90 ± 3 and 53 ± 2%, respectively. The calculated EC50 of diltiazem was 0.01035 mmol/l, whereas the EC50 of magnesium was 4.064 mmol/l (P < 0.05). Both magnesium and diltiazem produced vasorelaxation on phenylephrine-precontracted rat aortic rings in this study, but the potency of diltiazem regarding the EC50 value was significantly higher than that of magnesium. Magnesium could be a candidate together with diltiazem to inhibit vasospasm on arterial grafts during coronary bypass surgery.