Sara Jodayree | Sharif University of Technology (original) (raw)

Papers by Sara Jodayree

Radiation Protection Dosimetry, Feb 18, 2010

A rapid bioassay method has been developed for the determination of (90)Sr in human urine samples... more A rapid bioassay method has been developed for the determination of (90)Sr in human urine samples. The method is based on on-cartridge decolourisation of urine sample, separation of (90)Y from (90)Sr on an anion exchange resin column and by determination of (90)Sr using a liquid scintillation analyser (LSA). Separation of (90)Y from (90)Sr was achieved through selective complexation of yttrium with phosphate and subsequent retention of the anionic yttrium phosphate species on anion exchange resin. A total recovery of 97 +/- 2 % was obtained for strontium with three washes. The minimum detectable activity for the method was 0.2 Bq or 40 Bq l(-1). Measurement accuracy (relative bias, B(r)) and repeatability (relative precision, S(B)) of the method for the determination of (90)Sr were found to be -1 and 4.7 %, respectively. Excellent linearity (r(2) &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.999) was established over an activity range from 3.25 x 10(2) to 3.25 x 10(4) Bq l(-1). The method was also found to be very robust (S(B) &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5 %) against the matrix effect from different urine samples. Performance of the rapid bioassay method for sensitivity, accuracy and repeatability evaluated against the performance criteria for radiobioassay (ANSI N13.30) was found to be in compliant. Considering the simplicity, excellent analytical figures of merit, fast sample turnaround time (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1 h) and cost efficiency (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;30 USD per sample) of the developed method, it is very promising as a rapid bioassay method for supporting the medical response to an emergency where internal contamination of (90)Sr is involved.

Oats contain molecules with well-known health benefits. Its fibers are used in different preparat... more Oats contain molecules with well-known health benefits. Its fibers are used in different preparations to improve gastro-intestinal health and to reduce blood cholesterol. Avenanthramides, a group of phenolic antioxidants only present in oats have been demonstrated to be bioavailable in animals and humans. In recent years, proteins from foods have been viewed as not just sources of essential amino acids but also as sources of biologically active peptides (e.g. antioxidant, antihypertensive, antitumor). Antioxidant activities have been reported for hydrolyzed proteins from wheat, rice and corn byproducts but not for those from oats. The objective of this thesis was to investigate the antioxidant properties of hydrolyzed oat proteins in three different conditions (in vitro and in vivo). The first part of this thesis focusses on the activity of proteins extracted in the presence of salt and digested with trypsin (TPH) and alcalase (APH). The digests TPH and APH were ultra-filtered using 2kDa, and 10kDa molecular cutoff membranes. The radical scavenging properties were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance assay (ORAC). It was found that APH 2kDa was the strongest inhibitor (35%) of DPPH radicals and also TPH had a better peroxyl radical scavenging activity (ORAC) 434 ±16 µmol trolox equivalents (TE)/g) compared to APH (269±4 µmol TE/g) and TPH>2kDa (345±15 µmol TE/g). In the metal chelating assay, trypsin digest (TPH) better chelated Fe 2+ ions compared to APH and other fractions. The inhibition of linoleic acid autoxidation, showed that both trypsin and alcalase digests equally lowered the formation of lipid peroxides after five days of incubation. It appeared that trypsin hydrolysate and its ≤2kDa fraction possessed the strongest activities and may have application in food products.

Radiation Protection Dosimetry, 2010

International Journal of Food Science and Nutrition Engineering, 2014

The aim of this study was to assess the effect of three concentrations of oat bran protein hydrol... more The aim of this study was to assess the effect of three concentrations of oat bran protein hydrolysate (OPH) (1, 10, 10 mg/g diet) on oxidative stress marker in high fat fed animals. CD-1 male mice were placed into five groups and fed normal diet (ND), high fat (HF), and HF containing 1, 10, and 100 mg OPH/g of HF-diet for 3 weeks. Blood was collected at necropsy and analyze for glucose and markers of oxidative stress. At the highest level of OPH the oxygen radical absorbance capacity value of erythrocytes (123.1 ± 11.1 mMTrolox equivalents (TE)/mL blood) was higher (p < 0.05) than the value of HF group (96.5 ± 6.6 mM TE/mL) indicating higher scavenging activity that may be explained by higher thiol concentration detected. Liver superoxide dismutase (SOD) antioxidant enzyme activity was 13.2% lower in mice on HF-diet compared to those who received normal diet. Supplementation of HF-diet with OPH increased SOD activity to ND group level. OPH also had positive effect on respiratory exchange ratios but did not affect liver scavenging activity, calorie intake or bodyweight.In conclusion, addition OPH to HF diet increased radical scavenging activity in erythrocytes and SOD activity in mice liver samples.

Oat is an important cereal for human consumption and has relatively higher protein content compar... more Oat is an important cereal for human consumption and has relatively higher protein content compared to other cereals. Numerous studies have shown that oat polyphenols had antioxidant properties but no data is available for similar activity on proteins and peptides. The objective of this study was to investigate the antioxidant activities of tryptic and alcalase digests of oat flour protein isolates and ultra-filtered fractions. Oat flour protein hydrolysates from alcalase (APH) and trypsin (TPH) were therefore prepared and ultrafiltered using 2 and 10 kDa molecular cutoff membranes. The free radical scavenging properties were investigated by 2,2’-diphenyl-2-picrylhydrazyl (DPPH), oxygen radical absorbance capacity, linoleic acid emulsion system and ferrous ion-chelating assays. APH and TPH significantly reduced the generation of lipid hydroperoxides resulting from autoxidation of linoleic acid after 5 days incubation. At concentration of 200 :g/L, APH and TPH also showed better chel...

Free Radical Biology and Medicine, 2013

to up-regulate antioxidant defense pathways once consumed. Therefore, we tested a number of plant... more to up-regulate antioxidant defense pathways once consumed. Therefore, we tested a number of plant extracts for their ability to activate the Nrf2-ARE pathway using an ARE-luciferase reporter cell line as a primary screen, followed by RT-qPCR expression analyses of genes highly responsive to the Nrf2-ARE pathway (e.g., hemeoxygenase-1). Extracts that showed high activity were subsequently tested in combinations of three or four botanicals. We found that the combination of turmeric, quercetin, and rosemary (TQR) in a ratio of 1:3:5 synergistically activated Nrf2. This was supported by a corresponding synergistic increase in hemeoxygenase-1 expression in vitro. Finally, preliminary clinical data suggest a promising impact on oxidative stress in vivo based on reduction of urinary 8-isoprostane levels. These results demonstrate that it is possible to effect a reduction in oxidative stress markers with a combination of botanical extracts selected for their ability to induce endogenous antioxidant pathways.

Food Research International, 2012

In this study, medium oat bran samples were treated with four cell wall carbohydrases degrading e... more In this study, medium oat bran samples were treated with four cell wall carbohydrases degrading enzymes (viscozyme® L, α-amylase, amyloglucosidase, celluclast®). Their effects on protein extraction efficiency and, on antioxidant properties of obtained protein isolates and resulting alcalase hydrolysates were investigated. The results showed that sample pre-treated with amyloglucosidase (8 units/g) had the higher protein content (82%) while celluclast (5-60 endo-glucanase units (EGU)/g) pre-treated samples had protein content similar to that of control (54%). In the oxygen radical absorbance assay (ORAC) all samples of protein isolates had significantly higher peroxyl radical scavenging activity than the control. The sample pre-treated with alpha-amylase (2300 units/g) displayed the highest activity with an ORAC value of 165 ± 16 μM Trolox Equivalents (TE)/g. Proteins were hydrolyzed with alcalase and radical scavenging activities of hydrolysates assessed by ORAC and HO• radical assays. Sample pre-treated with viscozyme 1.5 Fungal Beta-glucanase Units (FBU)/g was the more active in both assays: ORAC value 521 ± 53 μM TE/g and HO• radical inhibition 26.3 ± 1.5%. A tandem mass spectrometric analysis of multiple charged ions within the hydrolysates allowed the identification of four new peptides.

Free Radical Biology and Medicine, 2012