Potential angiotensin I converting enzyme inhibitory peptides from gluten hydrolysate: Biochemical characterization and molecular docking study

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 IC₅₀ 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.     

A bioinformatic insight into the genetic diversity within pomegranate cultivars: from nuclear to chloroplast genes

Genetic Resources and Crop Evolution - The pomegranate (Punica granatum L.) is an ancient fruit plant which has been consumed for its nutritional value and medicinal properties by mankind. Several...     

Effects of silver nanoparticle size, concentration and coating on soil quality as indicated by arylsulfatase and sulfite oxidase activities

Recently, the nanotechnology industry has seen a growing interest in integrating silver nanoparticles (AgNPs) into agricultural products, which increases soil exposure to these particles. This demands an investigation into the effect of AgNPs on soil health. Changes in soil enzyme activities upon exposure to AgNPs can serve as early indicators of any adverse effects that these particles may have on soil quality. This study aimed to determine the effects of AgNP size, concentration, coating, and exposure time on the activities of two sulfur cycle enzymes, arylsulfatase and sulfite oxidase. To investigate the sensitivity of soil enzyme activity to AgNP contamination, silt loam soil samples were treated with 30, 80, and 200 nm-sized AgNPs coated with citrate, lipoic acid, and polyvinylpyrrolidone at 1, 10, and 100 mg Ag kg^-1 soil, with the changes in enzyme activities monitored at 3 h, 3 d, and 30 d after treatment. For comparison, the effects of silver (Ag) ions on the enzyme activities were studied under similar treatment conditions. For most of the concentrations tested, the inhibitory effects of AgNPs on different enzymes differed, with a much stronger effect on sulfite oxidase activity than on arylsulfatase activity. The AgNP concentration and exposure time played much important roles than coating type and particle size in the effects of AgNPs on soil enzyme activities.     

Monitoring of the fermentation media of citric acid by the trimethylsilyl derivatives of the organic acids formed

In this approach, a derivatization method is described for monitoring of organic acids in fermentation media without any separation step. The aqueous phase of fermentation media was evaporated and heated in a silylation reagent to form trimethylsilyl (TMS) derivatives. The silylated compounds are analyzed by 29Si nuclear magnetic resonance (29Si NMR) and gas chromatography-mass spectrometry (GC-MS). 29Si NMR can qualitatively monitor the components produced in the Krebs cycle. Quantification of these compounds is investigated by using selected ion monitoring mode of mass spectrometry. In this mode, mass to charge (m/z) values of their [M - 15]+ ions, which are 465, 275, 247, 221, 335, 251, and 313 of TMS derivatives of citric, alpha-ketoglutaric, succinic, fumaric, l-malic, oxaloacetic, and palmitic (as an internal standard), acids, respectively, are used. The limit of detection and the linear working range for derivatized citric acid were found to be 0.1 mg L(-1) and 10-3 x 10(4) mg L(-1). The relative standard deviation of the method for five replicates was 2.1%. The average recovery efficiency for citric acid added to culture media was approximately 97.2%. Quantitative results of GC-MS are compared with those obtained by an ultraviolet-visible method.     

Excess dietary iodine intake in long-term African refugees

OBJECTIVE: To assess the iodine status of long-term refugees dependent on international food aid and humanitarian assistance. DESIGN: A series of cross-sectional two-stage cluster or systematic random sample surveys which assessed urinary iodine excretion and the prevalence of visible goitre. Salt samples were also collected and tested for iodine content by titration. SETTING: Six refugee camps in East, North and Southern Africa. SUBJECTS: Male and female adolescents aged 10-19 years. MAIN RESULTS: The median urinary iodine concentration (UIC) ranged from 254 to 1200 microg l(-1) and in five of the camps exceeded the recommended maximum limit of 300 microg l(-1), indicating excessive iodine intake. Visible goitre was assessed in four surveys where it ranged from 0.0 to 7.1%. The camp with the highest UIC also had the highest prevalence of visible goitre. The iodine concentrations in 11 salt samples from three camps were measured by titration and six of these exceeded the production-level concentration of 20 to 40 ppm recommended by the World Health Organization (WHO), but were all less than 100 ppm. CONCLUSIONS: Excessive consumption of iodine is occurring in most of the surveyed populations. Urgent revision of the level of salt iodisation is required to meet current WHO recommendations. However, the full cause of excessive iodine excretion remains unknown and further investigation is required urgently to identify the cause, assess any health impact and identify remedial action.     

Chronic Ritalin Administration during Adulthood Increases Serotonin Pool in Rat Medial Frontal Cortex

Background: Ritalin has high tendency to be abused. It has been the main indication to control attention deficit hyperactivity disorder. The college students may seek for it to improve their memory, decrease the need for sleep (especially during exams), which at least partially, can be related to serotonergic system. Therefore, it seems worthy to evaluate the effect of Ritalin intake on mature brain. There are many studies on Ritalin effect on developing brain, but only few studies on adults are available. This study was undertaken to find Ritalin effect on serotonin transporter (SERT) density in medial frontal cortex (MFC) of mature rat. Methods: Thirty male Wistar rats were used in the study. Rats were assigned into five groups (n = 6 per group): one control, two Ritalin and two vehicle groups. Twelve rats received Ritalin (20 mg/kg/twice a day) orally for eleven continuous days. After one week of withdrawal and another two weeks of rest, in order to evaluate short-term effects of Ritalin, six rats were sacrificed. Another six rats were studied to detect the long-term effects of Ritalin; therefore, they were sacrificed 12 weeks after the previous group. The immunohistochemistry was performed to evaluate the results. Results: Immunohistochemistry studies showed a higher density of SERT in both 2 and 12 weeks after withdrawal from Ritalin intake in MFC of rat and there was no significant difference between these two groups. Conclusions: Our findings demonstrated both short- and long-term effects of Ritalin on frontal serotonergic system after withdrawal period.Key Words: Ritalin, Serotonin, Rats     

Evaluation of bone healing in canine tibial defects filled with cortical autograft,commercial-DBM,calf fetal DBM,omentum and omentum-calf fetal DBM

The present study was conducted to compare the effects of xenogenic bovine fetal demineralized bone matrix (DBM), commercial DBM, omentum, omentum-calf fetal DBM, cortical autograft and xenogenic cartilage powder on the healing of tibial defects in a dog model to determine the best material for bone healing. Seven male adult mongrel dogs, weighing 26.2 ± 2.5 kg, were used in this study. Seven holes with a diameter of 4-mm were created and then filled with several biomaterials. Radiographs were taken postoperatively on day 1 and weeks 2, 4, 6, 8. The operated tibias were removed on the 56th postoperative day and histopathologically evaluated. On postoperative days 14, 42 and 56, the lesions of the control group were significantly inferior to those in the other group (p < 0.05). On the 28th postoperative day, the autograft group was significantly superior to the control and omentum groups (p < 0.05). Moreover, calf fetal DBM was significantly superior to the control group. There was no significant difference between the histopathological sections of all groups. Overall, the omentum and omentum-DBM groups were superior to the control group, but inferior to the autograft, commercial-DBM, calf fetal DBM and calf fetal cartilage groups.     

Effects of methoxyfenozide and pyridalyl on the larval ectoparasitoid Habrobracon hebetor

Habrobracon hebetor Say (Hymenoptera: Braconidae) is an ectoparasitoid that is used for inundative biological control of various lepidopteran insect pests. Lethal and sublethal effects of two biorational insecticides, methoxyfenozide and pyridalyl, were evaluated on H. hebetor under laboratory conditions. The adults were exposed to dry insecticide residues that were applied on glass plates. Bioassays showed that the LC₅₀ values of methoxyfenozide and pyridalyl were 155 and 1,226 μg a.i./ml, respectively. The LT₅₀ values of methoxyfenozide and pyridalyl were 2.1 and 3.3 days, respectively. The effects of methoxyfenozide and pyridalyl on larvae were tested using a dip method with field-recommended concentrations of either insecticide. The emergence rates were reduced by 24.4 and 29.3 % for methoxyfenozide and pyridalyl treatments, respectively. In order to assess the sublethal effects of low-lethal concentrations of methoxyfenozide and pyridalyl, adult wasps were exposed to the LC₃₀ concentration of each insecticide, and demographic parameters of live wasps were recorded. Exposure of adults to low-lethal concentrations (LC₃₀) negatively affected the fecundity, fertility, and sex ratio, and also the intrinsic rate of increase (r _m), finite rate of increase (λ), generation time (T), and doubling time (DT). The longevity and net reproductive rate (R ₀) of H. hebetor were not affected by sublethal exposure to these insecticides. The results showed that despite low acute toxicities of both insecticides on larval and adult stages of H. hebetor, they may negatively affect the population of the parasitoid and interfere in IPM programs.