Search

Bioactive peptides of marine organisms have recently attracted great attention from scientists and industries. In this study, tissue protein of sea cucumber Holothuria parva muscle were hydrolyzed using bacterial alcalase enzyme and then sea cucumber protein hydrolysis (SPH) was separated by ultrafiltration membranes (30, 10 and 3 kDa) and four fractions with different molecular weight; FI (> 30 kDa), FII (10 < MW < 30 kDa), FIII (3 < MW < 10 kDa) and FIV (< 3 kDa) were obtained. The antioxidant and ACE-inhibitory of SPH and four fractions products FI, FII, FIII, and FIV were evaluated. The results show that the protein content of four fractions FI, FII, FIII, and FIV were 47.33, 57.08, 47.66, and 15.5 mg/ml, respectively. The results of biological analyzes showed that SPH exhibited the highest hydroxyl radical scavenger (48% at 10 µg/ml) and ferric ions (229.03% µg/mg) followed by FIV by (35% at 10 µg/ml). The highest ferric reducing was seen at SPH with (229.03 % at 10 µg/ml) followed by FIV (146/94% at 10 µg/ml). The DPPH scavenging activity of SPH, FI, and FII were 7.32%, 27.4%, and 6.77% at 10 µg/ml, respectively. The Angiotensin-I-converting enzyme (ACE) inhibitory activity of 1mg FI, FII, FIII, and FIV were 7.60, 3.73, 7.86, and 13.60 mg/ml, respectively. The fraction with molecular weight below 3 kDa exhibited higher ACE inhibitory activity. The results of the current study showed that the H. parva muscle protein and their hydrolysis products has a suitable capacity for use in medical purposes.

Bioactive peptides from marine protein sources hold tremendous promise as potent antioxidant agents with plausible anticancer activity. Herein, the antioxidant activities of crab protein hydrolysat...

Persian Gulf cuttlefish mantles were hydrolyzed (CPH) using alcalase, and the optimal hydrolysis parameters were obtained for the highest degree of hydrolysis (DH) and strongest antioxidant (based ...

Bioactivities (including antioxidative and antiproliferative properties) of cuttlefish mantle protein hydrolysates (CPH) with the degree of hydrolysis (DH) of 20.9, 25.5, 30.6, 35.3 and 40.6% (shortened as 20, 25, 30, 35 and 40%, respectively) prepared using alcalase were evaluated. The results indicated that the CPH with 20, 30 and 40% DH showed the greatest activity against DPPH radical scavenging [5.2 µmol TE (torolox equivalent)/g sample], reducing power (0.4 absorbance at 700 nm) and total antioxidant capacity (0.6 mg ascorbic acid equivalent/g sample), which were 2.5, 6.5 and 13.8 times higher than the cuttlefish mantle protein isolate (CPI), respectively. The CPH with the DH of 20% had the highest effect against MDA-231 and T47D cancer cell lines with growth inhibition of 78.2 and 66.2%, which were 6.5 and 6 times higher activities compared to the CPI, respectively. The amino acid profile of CPH indicated that glutamine (15.7%) and asparagine (10.9%) were predominant.

The study tests the physiological responses of Persian sturgeon, Acipenser persicus, during the abrupt release of juveniles from freshwater (FW) into brackish waters (BW=11 parts per thousand) of the Caspian Sea. Fish weight at release was 2-3g (2.55 +/- 0.41g; 8.8 +/- 0.58cm TL). Totals of 160 individuals were randomly distributed into four fiber-glass aerated tanks (volume 60-L). Two tanks served as controls (FW groups), and two as exposure tanks for BW (Caspian Sea water=CSW). Fish were sampled at 0, 3, 6, 12, 24, 48 and 96hr after abrupt transfer to CSW. Plasma osmolality, immunolocalization of Na+, K+ -ATPase (NKA) and Na+/K+/2Cl(-) (NKCC) Co-transporter, NKA activity and the NKA -subunit mRNA expression were analyzed. Blood osmolality of fish transferred from FW to CSW increased significantly within hours post-transfer (p

Background: Sea anemones are toxic sedentary invertebrates that are often present in the intertidal zone. Objectives: In this study, cytotoxic effects of the crude extract and its fractions from the oral disk of Stichodactyla haddoni on breast cancer cell line MCF-7 were investigated. Methods: Samples were collected from the intertidal zone in the Persian Gulf. Phosphate buffer saline (PBS) and Millipore filters were used to prepare the crude extract and its fractions, respectively. MCF-7 cells were exposed to the crude extract or one of its five fractions, (with molecular weights 100 kDa) at concentrations of 200 to 1400 μg/mL for 24 to 48 hours. Results: All treatments inhibited the growth of MCF-7 cancer cells. The highest inhibitory effect belonged to fractions 2 and 5, with 85 and 81.3% lethality, respectively. These fractions with the concentration of 1200 and 1400 μg/mL had the most anticancer effects against MCF-7. Conclusions: The 1200 μg/mL concentration of fraction 5 containing peptides < 3 kDa is recommended for separation and purification of its components for pharmacological studies to control breast cancer.

Global DNA methylation, as an epigenetic modifications, can be a promising genomic marker for monitoring the contaminants and predicting their adverse health effects. The study aims to assess the effects of 16 PAH concentration on the altered DNA methylation levels in the kidney and liver of rock pigeon (Columba livia), as a sentinel species, from Tehran megacity as well as 40 days benzo(a)pyrene in vitro exposure: (0.1, 2.5, 5, 7.5, and 10 mg kg−1 bw). Data indicated that the total LMW-PAH (low molecular weight PAHs) group (120.22, 121.34, 103.69, and 128.79 ng g−1 dw in liver, kidney, skin, and muscle, respectively) in the Tehran samples have higher levels than the other PAHs groups. In addition, the DNA methylation level had negative relation with the total amount of PAHs in liver and kidney. A comparatively higher global DNA hypomethylation (by 8.65% in liver and 3.76% in kidney) was observed in birds exposed to B(a)P. Our results lead us to suggest that DNA hypomethylation in liver and kidney associated with the B(a)P may be useful biomarker discovery (more than the amount of PAH concentration in different tissues of C. livia) in urban areas. In conclusion, based on the overall results assessed, DNA methylation changes in pigeon may show a new target pathway for evaluation of environmental health.

The effects of dietary n-3 highly unsaturated fatty acids [eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)] with α-tocopherol on growth, non-specific immune response and oxidative status were investigated in Caspian brown trout, Salmo trutta caspius, fry. Six experimental diets containing three different dietary levels of n-3 HUFAs (low: 1 + 0.5% of total fatty acids, DHA+ EPA, medium: 2 + 1%, DHA + EPA, high: 4 + 2%, DHA + EPA) with two different levels of α-tocopherol (low: 300 and high: 1000 mg kg−1 diet) were prepared and named: LL, LH, ML, MH, HL and HH (HUFA/α-tocopherol) groups, respectively. Diets were fed to triplicate groups of 60 fry with an initial weight of 600 ± 25 mg for 10 weeks. Results showed that increase in dietary DHA and EPA up to high level improved fry growth in terms of the body weight and specific growth rate, particularly when dietary α-tocopherol levels were high, suggesting a higher antioxidant protection value when these fatty acids are high. At all dietary n-3 HUFA levels, increase in α-tocopherol from low to high level enhanced the alternative complement (ACH50) activity. Fry fed diets medium and high n-3 HUFA displaying significantly higher lysozyme activity (P

The current study was conducted to evaluate the effects of UV-B radiation on survival rate and histopathological changes in the skin structure and ultrastructure in rainbow trout (Oncorhynchus mykiss) alevins. In laboratory dark conditions, newly hatched rainbow trout alevins were exposed to two different doses of UV-B radiation (high dose: HD: 94.83 μW cm(-2)) and (low dose: LD: 68.75 μW cm(-2)) for 9 days (time of exposure: 15 min per day), whereas specimens kept in darkness served as a control group. At the end of the experiment, alevins exposed to HD-UVB had the lowest survival rate (43.9 ± 0.9%), whereas fish exposed to LD-UVB showed intermediate values (73.6 ± 0.4%) with regard to the control group (91.2 ± 0.2%). Light microscopic and scanning electron microscopic studies revealed necrosis, sunburned cells, epidermis lifting of the epidermis, reduced number of mucous cells, degeneration of mucous cells and destruction of pavement cell microridges in both UV-B exposed groups. Hemorrhage and inflation in the meningeal layer of the brain were also observed in 17% and 42% of fish exposed to LD- and HD-UVB, respectively.

The use of chemical pesticides has increased environmental pollution and affects fishes as non-target organisms. To investigate the toxic effects of the widely used herbicide atrazine on Caspian kutum Rutilus frisii kutum fingerlings, fish were exposed to a sublethal con- centration of half LC50 for 96 h. The main alterations visible in the gill tissue were detachment of the epithelium of the lamellae, necrosis, lamellar fusion, hyperplasia, club shaped lamellae, col- lapse of the lamellae, shrinkage and curling of the lamellae, and ultrastructural alterations such as necrosis of the apical microridges of the pavement cells. Results also showed that the gill ionocytes were fewer in number and larger in size in the atrazine-exposed fish. Atrazine appears to be highly toxic to Caspian kutum fingerlings even at a sublethal concentration (12.47 mg l �1 ) and acute exposure. This toxicity could affect gill respiration and ion regulation function of fingerlings by damaging tissue, pavement cells, and ionocytes.

This study provides the first data on distribution of phthalate Acid esters (PAEs) in surface sediment samples taken from Anzali Wetland, Iran. These samples were collected from 43 stations. Two PAEs consist of di(2-ethylhexylphthalate) (DEHP) and di-n-butyl phthalate (DnBP) were detected and the total concentrations of these two pollutants ranged from 0.25 to 43.12, 0.12 to 19.02 μg g −1 dry weight, respectively. Among all the 43 samples analyzed, no sample was found to be free of DEHP and DBP, which indicates these two phthalate esters were ubiquitous in sediments. The concentrations in the near urban regions were higher than other regions because of higher discharge of PAEs from plastic materials in urbanized areas. Concentrations of PAEs were positively correlated with total organic carbon (TOC). Generally the median concentrations of DEHP and DnBP in the sediments were 15 and 14 times higher than the ERL. These results show that the Anzali wetland are highly polluted by major PAE congeners consist of DEHP and DnBP.

Effect of starvation and refeeding on the structure of pyloric caeca was studied in the juveniles of Caspian Sea salmon. Juveniles (average body weight 12±0.1g) were subjected to four levels of feeding: full-fed for 6 weeks (FFF), 3 weeks fed and 3 weeks following starvation (FS), 3 weeks starved and 3 weeks fed (SF), and full-starved (SSS) for 6 weeks. Light microscopic studies showed significant reduction (p0.05) in the enterocytes height and number, villus length, epithelial area and pyloric caeca total area in starved groups as compared to control group. These reductions were more significant (p0.05) in long term starved group (SSS) than short term starved group (FS). Additionally, refeeding increased pyloric caeca size and enterocyte's number in SF group whereas, the epithelial total area and villus length did not reach the same area and length as control group. Results indicated that in Caspian Sea salmon juveniles food deprivation and consuming of food source, adversely affected the tissue of pyloric caeca while refeeding can be effective on healing tissue damage.

Identification and some shell selection indices of Land Hermit Crabs, Coenobita scaevola (Forskal, 1775), were studied in the Larak Island from July 2009 to March 2010. This is the only hermit crab found on the island. Among 326 specimens studied, 15 different gastropod shell types were used by the crabs as shelters, the selection of which was found to be mainly related to the availability of the shells in the environment. More than 280 laboratory tests indicated that if there was no limitation in finding different species of gastropod shells, then the preferred species were different from those that were selected in the natural ecosystem. It was also found that the bigger the crab, the larger the shells that they preferred, rather than those that fitted them, so that the shell could be used for longer periods of time.

Localization of Na+, K+-ATPase-rich cells in the gill and urinary system of Acipenser persicus fry was performed through immunofluorescence light microscopy using a mouse monoclonal antibody IgGα5 raised against the α-subunit of chicken Na+, K+-ATPase. Different types of epithelia were clearly identified in the gill epithelium: epithelia of branchial arch, interbranchial septum, filament and lamellar epithelium. The Na+, K+-ATPase-rich cells were found in the epithelia of branchial arch, interbranchial septum, filament, interlamellar region and also in the lamellae. Histologically, the urinary system is divided into head kidney, trunk kidney and short caudal kidney. The head kidney is composed of the pronephric tubules and the haemopoietic tissues, while the trunk kidney is composed of a large number of glomeruli and convoluted nephrons. Each nephron consisted of a large glomerulus and tubules (neck, proximal, distal and collecting tubules) which connected to ureters. Posteriorly, ureters extended and joined together to form a small urinary bladder. In the urinary system, no specific fluorescence staining was observed in the glomerulus, neck segment and proximal tubules. The distal tubule cells and collecting tubule cells showed a strong immunostaining of Na+, K+-ATPase. Epithelia of ureters and urinary bladder also showed several isolated immunofluorescent cells. Immunofluorescent cells were rich in Na+, K+-ATPase enzyme which is very important for osmoregulation.

The effect of abrupt and 5-day gradual salinity transfers from freshwater (FW) to 11 ‰ Caspian Sea brackish water (BW) was investigated in juvenile Persian sturgeon Acipenser persicus with three different weight groups: 1–2 g (1.62 ± 0.27 g), 2–3 g (2.55 ± 0.41 g) and 3–5 g (4.28 ± 0.76 g). Mortality rates, blood osmotic pressure, gill morphology and branchial Na+, K+-ATPase (NKA) activity were measured 4 and 10 days after abrupt transfer and 9 and 15 days after the initial gradual transfer (i.e. 4 and 10 days after reaching Caspian Sea salinity). Fish under 3 g could not survive increased salinity, and the blood osmotic pressure of the remaining surviving fish increased and remained elevated. However, heavier fish were able to survive and successfully acclimate, even to rapid salinity change with osmotic pressure reduced to Caspian Sea osmolality levels. At the gill level, the developmental increase in chloride cell volume and a higher NKA content most probably allow juveniles weighing more than 2 g to sharply increase NKA activity if the fish are transferred to BW. The rapid chloride cell proliferation occurring with increased salinity should strengthen this acclimation response. Therefore, a drastic physiological change occurs when fish weigh more than 2 g that allows migration to higher salinities. The triggering signal on chloride cells must be further investigated in order to optimize this functional step.

We investigated the effects of salinity and artificial UV radiation on the accumulation of mycosporine-like amino acids (MAAs) in sexual and parthenogenetic Artemia from Lake Urmia. The nauplii hatched from the cysts were cultured until adulthood under two salinities (150 and 250 g L(-1) ) and two light treatments (PAR and PAR+UVR) in the laboratory. Finally, the Artemia were analyzed for their concentration of MAAs. In most of the cases, the higher salinity level applied was found to increase the MAA concentrations in both Artemia populations significantly. The acquisition efficiency of MAAs in both Artemia populations increased under exposure to UVR-supplemented photosynthetically active radiation (PAR) compared to those raised under PAR, except for Porphyra-334. It was observed that combination of UV radiation and elevated salinity significantly increased the bioaccumulation of MAAs. Thus, the presence of these compounds in these populations of Artemia may increase their adaptability for living in high-UV and high-salinity conditions prevailing in Lake Urmia. Higher concentrations of MAAs in the parthenogenetic population of Artemia could be probably attributed to its mono sex nature and higher adaptation capacities to extreme environmental conditions.

Unlike in crustacean freshwater species, the structure and ultrastructure of the excretory antennal gland is poorly documented in marine species. The general organization and ultrastructure of the cells and the localization of Na+,K+-ATPase were examined in the antennal gland of the adult lobster Homarus gammarus. Each gland is composed of a centrally located coelomosac surrounded ventrally by a labyrinth divided into two parts (I and II) and dorsally by a voluminous bladder. There is no differentiated nephridal tubule between them. The labyrinth and bladder cells have in common a number of ultrastructural cytological features, including basal membrane infoldings associated with mitochondria, apical microvilli, and cytoplasmic extrusions, and a cytoplasm packed with numerous vacuoles, vesicles, lysosome-like bodies, and swollen mitochondria. Each type of cell also presents distinctive characters. Na+,K+-ATPase was detected through immunofluorescence in the basal part of the cells of the labyrinth and in the bladder cells with an increasing immunostaining from labyrinth I to the bladder. No immunoreactivity was detected in the coelomosac. The cells of the labyrinth and of the bladder present morphological and enzymatic features of ionocytes. The antennal glands of the lobster thus possess active ion exchanges capabilities.

ment for the accessory molecules invariant chain (Ii) and HLA-DM is well established, less is known about how allelic variability affects HLA-DR assembly in the endoplasmic reticulum (ER), orwhether HLADP and HLA-DQ assemble in the same way as HLA-DR. Here, we ask if different DRb chains influence the stability of the DRab complex against the same intracellular background. We also compare the assembly of HLA-DR with HLA-DP and HLA-DQ. Our findings raise the possibility that, under certain circumstances, HLA-DP may present non-classical peptides to the immune system. Email Address for correspondence: m.j.t.m.van-lith@durham.ac.uk