National Institute of Nutrition
National Institute of Nutrition
News Article | May 29, 2017
The exact nature of the link between sea temperature and blindness in salmon has been established by scientists at Norway’s National Institute of Nutrition and Seafood Research (NIFES). Farmed salmon often lose their sight in summer, when rising temperatures cause cataracts that make their eyes opaque, which is a serious welfare problem. “These are permanent damages to the lens. The worst case scenario is that the vision is so impaired that the fish cannot see the feed, stop eating and stop growing,” said Sofie Remø, scientist at NIFES. “Since salmon is cold-blooded, the body temperature is the same as the temperature of the water. The optimal temperature for Atlantic salmon is about 13 degrees. If it gets warmer than that, the salmon will not perform as well and be at greater risk of developing cataracts,” she added. In nature, wild salmon can move to deeper and colder waters when temperatures rise, but that is not a possibility in sea cages. The past summers have seen periods of high seawater temperatures in Norway, and Remø says that many fish farmers contact NIFES with questions about cataracts during such periods. “Summer is the cataracts season. Since we are facing climate changes, the ocean temperatures will become even warmer, which makes it important to have knowledge about what happens to fish when the temperature rises so that we can safeguard their health and welfare,” she explained. The NIFES study demonstrates that several changes take place in the lens when water temperatures rise. - not least that the lens runs out of antioxidants. The antioxidants protect the lens from damage, and when there is not enough of them, the proteins are destroyed and white spots form in the lens. This is called oxidative stress. “The lens is a small sphere of transparent protein. It is a little like egg white, which also consists of transparent protein. When the egg is cooked, the proteins are destroyed and turn white. Something similar happens in the eye of a salmon when the proteins are destroyed, and they are no longer transparent,” said Remø. At the same time, the lens changes in a way that resembles the changes seen in people who develop cataracts due to diabetes. The blood sugar levels of salmon living in the warmest water increased, and this had consequences for the lens. “When the blood sugar level rises, there is an overload of sugar in the lens, and we see an accumulation of sugar alcohol,” Remø reflected. This causes problems with the water balance in the lens. The lens must contain the correct amount of water in order to remain transparent. If it swells up or dries out, this could damage the cells and result in cataract formation. Scientists call this osmotic stress. The scientists noticed that the lenses of salmon living in the warmest water had a lower ability to regulate this balance because they had less osmolytes, whose function is to transport water out of the cells. Cataracts have only been a major problem in aquaculture the past 20 years. Before that, animal by-products such as blood meal were used in fish feed, but this practice was discontinued in the 1990s due to the perceived risk of transferring BSE. Without the blood meal, and with less fishmeal in the feed, farmed salmon lost an important source of histidine. Histidine is an essential amino acid, which makes it an important building block in proteins. In addition, this amino acid can function as an antioxidant and osmolyte. This means that histidine can both protect the cells from oxidative stress and help maintain the water balance in the lens, which is why histidine can protect against cataract development. The salmon has to get all the histidine it needs to cover the nutritional requirement through the feed. However, not all of the raw materials used in feed production contain enough histidine, and therefore it is common practice to add synthetic histidine to the feed. The scientists at NIFES have previously found that Atlantic salmon need almost twice as much histidine to minimize cataracts, as it needs to sustain growth. This is particularly important right after the smolt are transferred to sea cages and when the temperature rises. However, this is not always enough to eliminate cataracts. “We have identified the underlying causes of why salmon are more susceptible to cataracts during the summer. This will form the basis for further work to increase robustness of the fish when facing environmental changes,” Remø concluded.
News Article | October 25, 2016
The German submarine U-864 was sunk in World War II off the Norwegian island of Fedje, loaded with 67 tons of metallic mercury. When the wreck was discovered in 2003, some of the mercury was found leaking from broken containers. Now, researchers show that this material has contaminated sediments surrounding the wreck. But surprisingly, the scientists think the marine food web may not be substantially affected by the pollution, based on their analysis of crabs sampled near the sub (Environ. Sci. Technol. 2016, DOI: 10.1021/acs.est.6b02128). Crabs and other seafood are often contaminated with neurotoxic mercury from industrial pollution and fossil fuel burning that is deposited from the air onto the ocean surface, making its way into the food chain. So when the mercury-laden vessel was discovered at a relatively shallow depth of 150 m, scientists, fishermen, and government officials were concerned. To determine the wreck’s impact, Norway’s Coastal Administration sampled sediments, and the National Institute of Nutrition & Seafood Research collected crabs near the site. Frank Vanhaecke of Ghent University and his colleagues then analyzed the samples with a variety of methods, including measuring mercury isotope ratios using multicollector inductively coupled plasma-mass spectrometry. “In some sediment samples we could see small droplets of mercury,” Vanhaecke says. The wet sediments had 60 to 24,000 mg/kg of mercury—in comparison, background levels in ocean sediments are 0.02 to 0.1 mg/kg. The isotopic composition of mercury in the submarine was similar to that in the sediments. Notably, crabs collected within a four-nautical-mile radius of the wreck did not have significantly different mercury concentrations than those collected from other areas along the Norwegian coast. However, the isotopic results indicate that crabs in the immediate vicinity of the submarine did take on some mercury from the wreck in their brown meat. The researchers hypothesize that mercury levels in crabs are not elevated because the sandy seafloor has relatively little organic matter; this may have limited methylation of mercury from the wreck by microbes. Methylmercury is the most bioavailable and toxic form of the element. Instead of methylmercury, what little mercury the crabs absorbed from the wreck was likely ingested directly from the sediments. The results show no evidence that the metal transforms into the more toxic methylmercury, Vanhaecke says. That “would make the problem much more risky,” he says, and needs to be further assessed.
Mansoori T.,Anand Eye Institute |
Sarvepally V.K.,Pushpagiri Eye Institute |
Balakrishna N.,National Institute of Nutrition
Journal of Glaucoma | Year: 2016
Purpose: To determine prevalence and anterior segment morphology of plateau iris in patients with primary angle closure glaucoma (PACG) after laser peripheral iridotomy using ultrasound biomicroscopy (UBM). Methods: In this prospective study, 262 PACG patients and 144 normal controls underwent UBM examination. Plateau iris in a quadrant was defined by the presence of anteriorly directed ciliary process, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact in the same quadrant. At least 2 quadrants had to fulfill these UBM criteria. Results: UBM analysis showed plateau iris in 83/262 (31.68%, 95% confidence interval: 26.7%-37.9%) PACG eyes, it was common in female individuals (61.44%), and patients were significantly younger than PACG patients (P=0.006). Plateau iris was found in superior quadrant in 19/83 (22.89%) eyes, inferior quadrant in 19/ 83 (22.89%) eyes, nasal quadrant in 21/83 (25.3%) eyes, and temporal quadrant in 24/83 (28.91%) eyes. In plateau iris patients, the central anterior chamber depth was shallower, the anterior chamber angle, the scleral-iris angle, and the sclera-ciliary process angle were significantly narrower, and the trabecular ciliary process distance and the iris ciliary process distance were significantly shorter in patients than in PACG subjects. Conclusions: Patients with plateau iris had significantly shallow central ACD when compared with those with pupillary block and normal eyes. After laser peripheral iridotomy, about a third of PACG eyes had plateau iris. This is clinically important because these patients can develop synechial angle closure and should be followed up closely. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Sinha S.N.,Indian Institute of Toxicology Research |
Vasudev K.,Indian Institute of Toxicology Research |
Vishnu Vardhana Rao M.,National Institute of Nutrition
Food Chemistry | Year: 2012
A Quick Easy Cheap Effective Rugged and Safe (QuEchERS) extraction was developed and followed by selective analysis using a liquid chromatography-mass spectrometry method for the quantification of eighteen pesticides in vegetable samples. This method was accurate (≥99.5%), and it exhibited limits of detection and quantification values in the 0.006-0.091 and 0.020-0.314 μg kg -1 ranges, respectively. Furthermore, the coefficients of variations (≥0.9999) were less than 1% at the low μg kg -1 end of the method. Mean recoveries ranged between 94% and 102%, and relative standard deviations were below 10%. Based on these results, the methodology was proven to be highly efficient, robust, and suitable for monitoring the maximum residue limits (MRL) compliance of a wide range of commodity/pesticide combination. This method was successfully applied to the analysis of vegetable samples that were collected from different government farmers' markets and street shops in urban areas. The presence of target pesticides was found in the range of 0.016 and 50.85 μg kg -1. © 2011 Elsevier Ltd. All rights reserved.
Muthenna P.,National Institute of Nutrition
The British journal of nutrition | Year: 2012
Formation of advanced glycation end products (AGE) plays a key role in the several pathophysiologies associated with ageing and diabetes, such as arthritis, atherosclerosis, chronic renal insufficiency, Alzheimer's disease, nephropathy, neuropathy and cataract. This raises the possibility of inhibition of AGE formation as one of the approaches to prevent or arrest the progression of diabetic complications. Previously, we have reported that some common dietary sources such as fruits, vegetables, herbs and spices have the potential to inhibit AGE formation. Flavonoids are abundantly found in fruits, vegetables, herbs and spices, and rutin is one of the commonly found dietary flavonols. In the present study, we have demonstrated the antiglycating potential and mechanism of action of rutin using goat eye lens proteins as model proteins. Under in vitro conditions, rutin inhibited glycation as assessed by SDS-PAGE, AGE-fluorescence, boronate affinity chromatography and immunodetection of specific AGE. Further, we provided insight into the mechanism of inhibition of protein glycation that rutin not only scavenges free-radicals directly but also chelates the metal ions by forming complexes with them and thereby partly inhibiting post-Amadori formation. These findings indicate the potential of rutin to prevent and/or inhibit protein glycation and the prospects for controlling AGE-mediated diabetic pathological conditions in vivo.
Muthenna P.,National Institute of Nutrition |
Akileshwari C.,National Institute of Nutrition |
Reddy G.B.,National Institute of Nutrition
Biochemical Journal | Year: 2012
Non-enzymatic glycation is a complex series of reactions between reducing sugars and amino groups of proteins. Accumulation of AGEs (advanced glycation end-products) due to non-enzymatic glycation has been related to several diseases associated with aging and diabetes. The formation of AGEs is accelerated in hyperglycaemic conditions, which alters the structure and function of long-lived proteins, thereby contributing to longterm diabetic complications. The present study describes AGE inhibition and the mechanism of action of a new antiglycating agent, EA (ellagic acid), a flavonoid present in many dietary sources. Inhibition of AGE formation by EA was demonstrated with different proteins, namely eye lens TSP (total soluble protein), Hb (haemoglobin), lysozyme and BSA, using different glycating agents such as fructose, ribose and methylglyoxal by a set of complementary methods. These results suggest that the antiglycating action of EA seems to involve, apart from inhibition of a few fluorescent AGEs, predominantly inhibition of CEL [N ε-(carboxyethyl)lysine] through scavenging of the dicarbonyl compounds. Furthermore,MALDI-TOF-MS (matrix-assisted laser-desorption ionisation-time-of-flight MS) analysis confirms inhibition of the formation of CEL on lysozyme on in vitro glycation by EA. Prevention of glycation-mediated β-sheet formation in Hb and lysozyme by EA confirm its antiglycating ability. Inhibition of glycosylated Hb formation in human blood under ex vivo high-glucose conditions signifies the physiological antiglycating potential of EA.We have also determined the effectiveness of EA against loss of eye lens transparency through inhibition ofAGEs in the lens organ culture system. These findings establish the antiglycating potential of EA and its in vivo utility in controlling AGE-mediated diabetic pathologies. © The Authors Journal compilation © 2012 Biochemical Society.
Reddy V.S.,National Institute of Nutrition |
Reddy G.B.,National Institute of Nutrition
Biochimica et Biophysica Acta - General Subjects | Year: 2016
Background Crystallins are the major structural proteins of vertebrate eye lens responsible for maintaining the refractive index of the lens. However, recent studies suggest that they also have a functional significance in non-lenticular tissues. Prolonged uncontrolled diabetes results in the development of macro and microvascular complications that are the leading causes of morbidity and mortality in diabetic patients all over the world. Scope of review Recent studies have shown that crystallins play an instrumental role in diabetes and its complications. Therefore, this review highlights the current data on the impact of chronic hyperglycemia on expression, distribution, glycation, phosphorylation, chaperone-like function and, anti-apoptotic activity of crystallins. Furthermore, we discussed the insights for developing therapeutic strategies for diabetic complications including natural agents, peptides, and pharmacological chaperones that modulate or mimic chaperone activity of α-crystallins. Major conclusions Upregulation of crystallins appears to be a common feature of chronic diabetes. Further, chronic hyperglycemia induces the glycation and phosphorylation of crystallins, mainly α-crystallins and thereby alters their properties. The disturbed interaction of αB-crystallin with various apoptotic mediators including Bax and caspases is also an important factor for increased cell death in diabetes. Numerous dietary agents, peptides, and chemical chaperones prevent apoptosis and the loss of chaperone activity in diabetes. General significance Understanding the role of crystallins will aid in developing therapeutic strategies for alleviating pathophysiological conditions such as protein aggregation, inflammation, oxidative stress and apoptosis associated with chronic complications of diabetes including cataract, retinopathy, and cardiomyopathy. This article is part of a Special Issue entitled Crystallin Biochemistry in Health and Disease. © 2015 Elsevier B.V.
Reddy V.S.,National Institute of Nutrition |
Reddy G.B.,National Institute of Nutrition
Current Molecular Medicine | Year: 2015
HSPB5 or αB-crystallin (αBC) is a major protein of the vertebrate eye lens belonging to the small heat-shock protein family of proteins that respond to various stressful conditions. αBC also is found outside the lens in various non-ocular tissues and acts as a molecular chaperone by preventing aggregation of proteins, inhibits apoptosis and inflammation, and maintains cytoskeletal architecture. The αBC protein is phosphorylated on three serine residues S59, S45, and S19, and several functions of αBC are modulated by phosphorylation. Numerous studies have revealed the upregulation of αBC in pathological conditions such as neurodegenerative diseases, cancers, diabetes, retinal diseases, cataracts, ischemia/repurfusion, aging, and others. However, it is unknown whether the up-regulation of αBC is causative or protective for these pathological conditions. Although αBC has been shown to provide a protective effect in neurodegenerative diseases, inflammation, diabetes, and retinal diseases, other studies have described a deleterious role of αBC in cancers and pulmonary fibrosis. The therapeutic potential of αBC alone or in combination with αA-crystallin has been reported. Acetylated αBC peptides have been shown to be more potent than native αBC for chaperone as well as therapeutic activities using both in vitro and in vivo models. Further, for efficient delivery of α BC into cells, carrier molecules such as polylacticcoglycolic acid, polycaprolactone and cell penetration peptides have been used. In this review, we have summarized current data from emerging and exciting studies of the therapeutic strategies of α BC and α BC peptides and the efficient delivery strategies of these proteins in various disease models, including neurodegenerative diseases, retinal diseases, platelet aggregation, inflammation, and ischemia. © 2015 Bentham Science Publishers.
Rajanna A.,National Institute of Nutrition
Medical Hypotheses | Year: 2016
Even though lots of efforts have been made to find different strategies for cancer treatments, currently available therapeutic approaches are chemotherapy, radiation and surgery or combination of these. These treatments prolonged the survival of patients but did not assure complete cure of the disease. Recent scientific evidences suggest that cancer stem cells (CSC) are responsible for recurrence, resistance and existence of this disease even after various therapeutic treatments. Therefore, we hypothesize that the best approach is to target CSCs along with cancer cells for complete remission of the disease. Before targeting these cells, studying their morphological, proliferation, behavioral aspects, physico-chemical interaction and characterizations are very important. For therapeutic approach the differentiation capacity of these cells to cancer cells with or without drugs is critical. To study basic parameters; the best approach would be aseptic sorting of CSCs from cancer cells based on specific cell surface markers by flowcytometer or magnetic cell sorter. The sorted cells have to be grown in culture conditions and treat with optimum concentrations of drugs to target CSC and cancer cell to find appropriate potential combination. © 2015 Elsevier Ltd.
Vijaya Kumar Reddy C.,National Institute of Nutrition |
Sreeramulu D.,National Institute of Nutrition |
Raghunath M.,National Institute of Nutrition
Food Research International | Year: 2010
Epidemiological studies from other parts of the world indicate that increased consumption of fruits and vegetables are associated with lower risk of chronic degenerative diseases. Fruits are an important component of Indian diets. Studies indicate that fruits and vegetables are rich sources of phenolic compounds and antioxidant activity (AOA). Present study was taken up to determine the AOA and phenolic content of fresh and dry fruits commonly consumed in India by two different (radical scavenging) methods and relate it to their total phenolic content (TPC) for the first time. Fourteen commonly consumed fresh fruits and ten dry fruits were studied. AOA and TPC contents of both fresh and dry fruits showed marked variation. Correlation analysis between the TPC and AOA as assessed by the two methods showed that phenolics may contribute maximally to the ABTS (r = 0.84) and to lesser extent to DPPH (r = 0.77) in fresh fruits, where as in dry fruits they correlated well to DPPH activity (r = 0.97) and to a lesser extent to FRAP (r = 0.87). In general, the results indicate that majority of the fresh and dry fruits studied are rich in phenolic antioxidants with potent free radical scavenging activity imply their importance to human health. © 2009 Elsevier Ltd. All rights reserved.