Defining the targets for the assessment of IgE-mediated allergenicity of new or modified food proteins.

Many food innovations rely on the introduction and use of new or modified proteins. New or modified food proteins may lead to major health risks due to their inherent potential to cause food allergy. Currently, the pre-market allergenicity assessment for new or modified food proteins and protein sources relies on methods for identifying allergenic hazards based on characteristics of known allergens. However, there is no general consensus on the allergenicity parameters to use and the criteria that should apply for the evaluation and decisions to be made. In this paper, we propose that the strategy for allergenicity risk assessment of new or modified food proteins and the methodologies applied should be governed by the risk management questions to be answered, reflected in the information needed by risk managers to enable their informed decision making. We generated an inventory of health outcome-related assessment parameters and criteria potentially important for risk management decision-making and we discuss the implications of selecting different optional criteria (e.g. cut-off values) for what could be accepted as safe with regards to the health outcomes in the (at risk) population. The impact of these various options on both method development and risk management practices was investigated.

Benefits and safety of dietary protein for bone health-an expert consensus paper endorsed by the European Society for Clinical and Economical Aspects of Osteopororosis, Osteoarthritis, and Musculoskeletal Diseases and by the International Osteoporosis Foundation.

A summary of systematic reviews and meta-analyses addressing the benefits and risks of dietary protein intakes for bone health in adults suggests that dietary protein levels even above the current RDA may be beneficial in reducing bone loss and hip fracture risk, provided calcium intakes are adequate. Several systematic reviews and meta-analyses have addressed the benefits and risks of dietary protein intakes for bone health in adults. This narrative review of the literature summarizes and synthesizes recent systematic reviews and meta-analyses and highlights key messages. Adequate supplies of dietary protein are required for optimal bone growth and maintenance of healthy bone. Variation in protein intakes within the "normal" range accounts for 2-4% of BMD variance in adults. In older people with osteoporosis, higher protein intake (≥ 0.8-g/kg body weight/day, i.e., above the current RDA) is associated with higher BMD, a slower rate of bone loss, and reduced risk of hip fracture, provided that dietary calcium intakes are adequate. Intervention with dietary protein supplements attenuate age-related BMD decrease and reduce bone turnover marker levels, together with an increase in IGF-I and a decrease in PTH. There is no evidence that diet-derived acid load is deleterious for bone health. Thus, insufficient dietary protein intakes may be a more severe problem than protein excess in the elderly. Long-term, well-controlled randomized trials are required to further assess the influence of dietary protein intakes on fracture risk.

Cost-Effectiveness of a Specialized Oral Nutritional Supplementation for Malnourished Older Adult Patients in Spain.

Malnutrition has been related to prolonged hospital stays, and to increases in readmission and mortality rates. In the NOURISH (Nutrition effect On Unplanned Readmissions and Survival in Hospitalized patients) study, administering a high protein oral nutritional supplement (ONS) containing beta-hydroxy-beta-methylbutyrate (HP-HMB) to hospitalised older adult patients led to a significant improvement in survival compared with a placebo treatment. The aim of this study was to determine whether HP-HMB would be cost-effective in Spain. We performed a cost-effectiveness analysis from the perspective of the Spanish National Health System using time horizons of 90 days, 180 days, 1 year, 2 years, 5 years and lifetime. The difference in cost between patients treated with HP-HMB and placebo was €332.75. With the 90 days time horizon, the difference in life years gained (LYG) between both groups was 0.0096, resulting in an incremental cost-effectiveness ratio (ICER) of €34,700.62/LYG. With time horizons of 180 days, 1 year, 2 years, 5 years and lifetime, the respective ICERs were €13,711.68, €3377.96, €2253.32, €1127.34 and €563.84/LYG. This analysis suggests that administering HP-HMB to older adult patients admitted to Spanish hospitals during hospitalisation and after discharge could be a cost-effective intervention that would improve survival with a reduced marginal cost.

Protein Supplement Usage Among Male University Students: Comparisons Between Current and Previous Users.

OBJECTIVE: Interest in specialized dietary supplements is leading market growth, and protein supplements are popular for increasing muscle mass among young males. Therefore, this study investigated the attitudes toward and satisfaction with protein supplements to identify detailed consumer behaviors related to the consumption of protein supplements. METHOD: The study sample includes male university students in their 20s in South Korea. In total, 223 responses were entered for analysis. Questions related to attitudes, satisfaction, and future behavioral intentions were asked using 5-point Likert scales. The responses were divided into two groups, current and previous users, to identify significant differences in terms of attitudes, satisfaction, and future behavioral intentions. A descriptive analysis, analysis of variance (ANOVA), and multiple regression were run. RESULTS: The majority of respondents prefer the powdered form of supplements in bulk with a price range between 30,000 won and 60,000 won. Online shopping was preferred, while word of mouth and friends/family were considered credible information sources. The most common side effects experienced were problems with digestion and hives, although more than 78% did not experience side effects. In comparison between current and previous users in terms of attitudes and satisfaction, the following areas showed significances. Regarding attitudes, the importance of brand, preference for products from overseas, the search for nutritional facts, and reading carefully all product information were significant, while regarding satisfaction, price, effectiveness, and ease of consumption were significant. All significances showed that current users had more positive attitudes and greater satisfaction. Overall, consumers' satisfaction regarding ease of consumption influenced future behavioral intentions. CONCLUSIONS: The market for protein supplements has been growing, so measuring consumers' attitudes and satisfaction would help attract potential consumers. In addition, analyzing previous users' opinions on products could guide product development and encourage customers to return for repurchase.

Race-dependent association of sulfidogenic bacteria with colorectal cancer.

OBJECTIVE: Colorectal cancer (CRC) incidence is higher in African Americans (AAs) compared with non-Hispanic whites (NHWs). A diet high in animal protein and fat is an environmental risk factor for CRC development. The intestinal microbiota is postulated to modulate the effects of diet in promoting or preventing CRC. Hydrogen sulfide, produced by autochthonous sulfidogenic bacteria, triggers proinflammatory pathways and hyperproliferation, and is genotoxic. We hypothesised that sulfidogenic bacterial abundance in colonic mucosa may be an environmental CRC risk factor that distinguishes AA and NHW. DESIGN: Colonic biopsies from uninvolved or healthy mucosa from CRC cases and tumour-free controls were collected prospectively from five medical centres in Chicago for association studies. Sulfidogenic bacterial abundance in uninvolved colonic mucosa of AA and NHW CRC cases was compared with normal mucosa of AA and NHW controls. In addition, 16S rDNA sequencing was performed in AA cases and controls. Correlations were examined among bacterial targets, race, disease status and dietary intake. RESULTS: AAs harboured a greater abundance of sulfidogenic bacteria compared with NHWs regardless of disease status. Bilophila wadsworthia-specific dsrA was more abundant in AA cases than controls. Linear discriminant analysis of 16S rRNA gene sequences revealed five sulfidogenic genera that were more abundant in AA cases. Fat and protein intake and daily servings of meat were significantly higher in AAs compared with NHWs, and multiple dietary components correlated with a higher abundance of sulfidogenic bacteria. CONCLUSIONS: These results implicate sulfidogenic bacteria as a potential environmental risk factor contributing to CRC development in AAs.

Resting energy expenditure, calorie and protein consumption in critically ill patients: a retrospective cohort study.

BACKGROUND: Intense debate exists regarding the optimal energy and protein intake for intensive care unit (ICU) patients. However, most studies use predictive equations, demonstrated to be inaccurate to target energy intake. We sought to examine the outcome of a large cohort of ICU patients in relation to the percent of administered calories divided by resting energy expenditure (% AdCal/REE) obtained by indirect calorimetry (IC) and to protein intake. METHODS: Included patients were hospitalized from 2003 to 2015 at a 16-bed ICU at a university affiliated, tertiary care hospital, and had IC measurement to assess caloric targets. Data were drawn from a computerized system and included the % AdCal/REE and protein intake and other variables. A Cox proportional hazards model for 60-day mortality was used, with the % AdCal/REE modeled to accommodate non-linearity. Length of stay (LOS) and length of ventilation (LOV) were also assessed. RESULTS: A total of 1171 patients were included. The % AdCal/REE had a significant non-linear (p < 0.01) association with mortality after adjusting for other variables (p < 0.01). Increasing the percentage from zero to 70 % resulted in a hazard ratio (HR) of 0.98 (CI 0.97-0.99) pointing to reduced mortality, while increases above 70 % suggested an increase in mortality with a HR of 1.01 (CI 1.01-1.02). Increasing protein intake was also associated with decreased mortality (HR 0.99, CI 0.98-0.99, p = 0.02). An AdCal/REE >70 % was associated with an increased LOS and LOV. CONCLUSIONS: The findings of this study suggest that both underfeeding and overfeeding appear to be harmful to critically ill patients, such that achieving an Adcal/REE of 70 % had a survival advantage. A higher caloric intake may also be associated with harm in the form of increased LOS and LOV. The optimal way to define caloric goals therefore requires an exact estimate, which is ideally performed using indirect calorimetry. These findings may provide a basis for future randomized controlled trials comparing specific nutritional regimens based on indirect calorimetry measurements.

Higher protein intake is associated with increased risk for incident end-stage renal disease among blacks with diabetes in the Southern Community Cohort Study.

BACKGROUND AND AIMS: Diabetes, a risk factor for end-stage renal disease (ESRD), is associated with impaired protein metabolism. We investigated whether protein intake is associated with ESRD and whether the risk is higher among blacks with diabetes. METHODS AND RESULTS: We conducted a nested case-control study of ESRD within the Southern Community Cohort Study, a prospective study of low-income blacks and whites in the southeastern US (2002-2009). Through 2012, 1057 incident ESRD cases were identified by linkage with the United States Renal Data System and matched to 3198 controls by age, sex, and race. Dietary intakes were assessed from a validated food frequency questionnaire at baseline. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed from logistic regression models that included matching variables, BMI, education, income, hypertension, total energy intake, and percent energy from saturated and polyunsaturated fatty acids. Mean (±SD) daily energy intake from protein was higher among ESRD cases than controls (15.7 ± 3.3 vs. 15.1 ± 3.1%, P < 0.0001). For a 1% increase in percent energy intake from protein, the adjusted ORs (95% CIs) for ESRD were 1.06 (1.02-1.10) for blacks with diabetes, 1.02 (0.98-1.06) for blacks without diabetes, 0.99 (0.90-1.09) for whites with diabetes and 0.94 (0.84-1.06) for whites without diabetes. Protein intake in g/kg/day was also associated with ESRD (4th vs. 1st quartile OR = 1.76; 95% CI: 1.17-2.65). CONCLUSION: Our results raise the possibility that among blacks with diabetes, increased dietary protein is associated with increased incidence of ESRD. Studies on how protein intake and metabolism affect ESRD are needed.

Healthcare Costs Associated with an Adequate Intake of Sugars, Salt and Saturated Fat in Germany: A Health Econometrical Analysis.

Non-communicable diseases (NCDs) represent not only the major driver for quality-restricted and lost life years; NCDs and their related medical treatment costs also pose a substantial economic burden on healthcare and intra-generational tax distribution systems. The main objective of this study was therefore to quantify the economic burden of unbalanced nutrition in Germany--in particular the effects of an excessive consumption of fat, salt and sugar--and to examine different reduction scenarios on this basis. In this study, the avoidable direct cost savings in the German healthcare system attributable to an adequate intake of saturated fatty acids (SFA), salt and sugar (mono- & disaccharides, MDS) were calculated. To this end, disease-specific healthcare cost data from the official Federal Health Monitoring for the years 2002-2008 and disease-related risk factors, obtained by thoroughly searching the literature, were used. A total of 22 clinical endpoints with 48 risk-outcome pairs were considered. Direct healthcare costs attributable to an unbalanced intake of fat, salt and sugar are calculated to be 16.8 billion EUR (CI95%: 6.3-24.1 billion EUR) in the year 2008, which represents 7% (CI95% 2%-10%) of the total treatment costs in Germany (254 billion EUR). This is equal to 205 EUR per person annually. The excessive consumption of sugar poses the highest burden, at 8.6 billion EUR (CI95%: 3.0-12.1); salt ranks 2nd at 5.3 billion EUR (CI95%: 3.2-7.3) and saturated fat ranks 3rd at 2.9 billion EUR (CI95%: 32 million-4.7 billion). Predicted direct healthcare cost savings by means of a balanced intake of sugars, salt and saturated fat are substantial. However, as this study solely considered direct medical treatment costs regarding an adequate consumption of fat, salt and sugars, the actual societal and economic gains, resulting both from direct and indirect cost savings, may easily exceed 16.8 billion EUR.

In vitro assessment of allergenicity features and localization of probable IgE binding regions.

Rice is cultivated as a staple grain crop in many countries, especially in Asia. In the present study, recombinant rice chitinase was expressed, purified and characterized by in silico and immunobiochemical methods. Rice chitinase was affinity purified and it resolved at 24 kDa on SDS-PAGE. Purified protein was analyzed for pepsin resistance, heat stability, and IgE binding using atopic patients' sera. Chitinase was resistant to pepsin digestion and heat treatment at 90 °C for 1 h. It showed significant IgE binding with 7 of 110 patients' sera positive to different food allergens. Homology modeled 3D structure of rice chitinase was used for B cell epitope prediction. In silico predicted B cell peptides were assessed for IgE binding by ELISA using food allergic patients' sera, epitope RC2 showed IgE binding comparable to chitinase. In conclusion, chitinase was identified as a potential allergen and may share cross reactive epitopes with food allergens.

Food safety assessment of an antifungal protein from Moringa oleifera seeds in an agricultural biotechnology perspective.

Mo-CBP3 is an antifungal protein produced by Moringa oleifera which has been investigated as potential candidate for developing transgenic crops. Before the use of novel proteins, food safety tests must be conducted. This work represents an early food safety assessment of Mo-CBP3, using the two-tiered approach proposed by ILSI. The history of safe use, mode of action and results for amino acid sequence homology using the full-length and short contiguous amino acids sequences indicate low risk associated to this protein. Mo-CBP3 isoforms presented a reasonable number of alignments (>35% identity) with allergens in a window of 80 amino acids. This protein was resistant to pepsin degradation up to 2 h, but it was susceptible to digestion using pancreatin. Many positive attributes were presented for Mo-CBP3. However, this protein showed high sequence homology with allergens and resistance to pepsin digestion that indicates that further hypothesis-based testing on its potential allergenicity must be done. Additionally, animal toxicity evaluations (e.g. acute and repeated dose oral exposure assays) must be performed to meet the mandatory requirements of several regulatory agencies. Finally, the approach adopted here exemplified the importance of performing an early risk assessment of candidate proteins for use in plant transformation programs.

Effect of protein overfeeding on energy expenditure measured in a metabolic chamber.

BACKGROUND: Energy expenditure (EE) increases with overfeeding, but it is unclear how rapidly this is related to changes in body composition, increased body weight, or diet. OBJECTIVE: The objective was to quantify the effects of excess energy from fat or protein on energy expenditure of men and women living in a metabolic chamber. DESIGN: We conducted a randomized controlled trial in 25 participants who ate ∼40% excess energy for 56 d from 5%, 15%, or 25% protein diets. Twenty-four-hour EE (24EE) and sleeping EE (SleepEE) were measured on days 1, 14, and 56 of overfeeding and on day 57 while consuming the baseline diet (usually day 57). Metabolic and molecular markers of muscle metabolism were measured in skeletal muscle biopsy specimens. RESULTS: In the low-protein diet group whose excess energy was fat, the 24EE and SleepEE did not increase during the first day of overfeeding. When extra energy contained protein, both 24EE and SleepEE increased in relation to protein intake (r = 0.50, P = 0.02). The 24EE over 8 wk in all 3 groups was correlated with protein intake (r = 0.60, P = 0.004) but not energy intake (r = 0.16; P = 0.70). SleepEE was unchanged by overfeeding in the low-protein diet group, and baseline surface area predicted increased 24EE in this group. Protein and fat oxidation were reciprocally related during overfeeding. Observed 24EE was higher than predicted on days 1 (P ≤ 0.05), 14 (P = 0.0001), and 56 (P = 0.0007). There was no relation between change in fat mass and change in EE. CONCLUSIONS: Excess energy, as fat, does not acutely increase 24EE, which rises slowly as body weight increases. Excess energy as protein acutely stimulates 24EE and SleepEE. The strongest relation with change in 24EE was the change in energy expenditure in tissue other than muscle or fat-free mass.

Nutritional ecology of obesity: from humans to companion animals.

We apply nutritional geometry, a framework for modelling the interactive effects of nutrients on animals, to help understand the role of modern environments in the obesity pandemic. Evidence suggests that humans regulate the intake of protein energy (PE) more strongly than non-protein energy (nPE), and consequently will over- and under-ingest nPE on diets with low or high PE, respectively. This pattern of macronutrient regulation has led to the protein leverage hypothesis, which proposes that the rise in obesity has been caused partly by a shift towards diets with reduced PE:nPE ratios relative to the set point for protein regulation. We discuss potential causes of this mismatch, including environmentally induced reductions in the protein density of the human diet and factors that might increase the regulatory set point for protein and hence exacerbate protein leverage. Economics--the high price of protein compared with fats and carbohydrates--is one factor that might contribute to the reduction of dietary protein concentrations. The possibility that rising atmospheric CO2 levels could also play a role through reducing the PE:nPE ratios in plants and animals in the human food chain is discussed. Factors that reduce protein efficiency, for example by increasing the use of ingested amino acids in energy metabolism (hepatic gluconeogenesis), are highlighted as potential drivers of increased set points for protein regulation. We recommend that a similar approach is taken to understand the rise of obesity in other species, and identify some key gaps in the understanding of nutrient regulation in companion animals.

Purification and characterization of parvalbumin isotypes from grass carp (Ctenopharyngodon idella).

The prevalence of fish allergy is rapidly increasing because of a growing fish consumption driven mainly by a positive image of the fish and health relationship. The purpose of this study was to characterize parvalbumin isotypes from grass carp (Ctenopharyngodon idella), one of the most frequently consumed freshwater fish in China. Three parvalbumin isotypes were purified using consecutive gel filtration and reverse-phase chromatography and denoted as PVI, PVII, and PVIII. The molecular weights of the isotypes were determined to be 11.968, 11.430, and 11.512 kDa, respectively. PVI showed 74% matched amino acids sequence with PV isotype 4a from Danio rerio, while PVII and PVIII showed 46% matched amino acids sequence with PV isotypes from Hypophthalmichthys molitrix. PVII is the dominant allergen, but it was liable to gastrointestinal enzymes as PVIII; however, PVI was resistant to pepsin digestion. A further study is to characterize the epitopes of PVII, the dominant allergen.

Protein needs early in life and long-term health.

The objective of this review was to summarize selected health aspects of protein intake during the first 2 y of life. During this period there is a marked increase in protein intake from an intake of ∼ 5% of energy from protein (PE%) in an exclusively breastfed infant to ∼ 15 PE% when complementary foods have been introduced. At this age, mean protein intake is ∼ 3 times as high as the physiologic requirement, but some children receive 4-5 times their physiologic requirement. Protein from cow milk constitutes a main part of protein intake in toddlers and seems to have a specific effect on insulin-like growth factor I concentrations and growth. Meat has a high protein content, but the small amounts of meat needed to ensure good iron status have less impact on total protein intake. The difference in protein intake between breastfed and formula-fed infants is likely to play a role in the difference between breastfed and formula-fed infants. There is emerging evidence that high protein intake during the first 2 y of life is a risk factor for later development of overweight and obesity. It therefore seems prudent to avoid a high protein intake during the first 2 y of life. This could be accomplished by decreasing the upper allowable limit of the protein content of infant formulas for the first year of life and limiting the intake of cow milk in the second year of life.

Dietary acid load and risk of type 2 diabetes: the E3N-EPIC cohort study.

AIMS/HYPOTHESIS: The objective of this study was to evaluate the prospective relationship between dietary acid load, assessed with both the potential renal acid load (PRAL) and the net endogenous acid production (NEAP) scores, and type 2 diabetes risk. METHODS: A total of 66,485 women from the E3N-EPIC cohort were followed for incident diabetes over 14 years. PRAL and NEAP scores were derived from nutrient intakes. HRs for type 2 diabetes risk across quartiles of the baseline PRAL and NEAP scores were estimated with multivariate Cox regression models. RESULTS: During follow-up, 1,372 cases of incident type 2 diabetes were validated. In the overall population, the highest PRAL quartile, reflecting a greater acid-forming potential, was associated with a significant increase in type 2 diabetes risk, compared with the first quartile (HR 1.56, 95% CI 1.29, 1.90). The association was stronger among women with BMI <25 kg/m2 (HR 1.96, 95% CI 1.43, 2.69) than in overweight women (HR 1.28, 95% CI 1.00, 1.64); statistically significant trends in risk across quartiles were observed in both groups (p trend < 0.0001 and p trend = 0.03, respectively). The NEAP score provided similar findings. CONCLUSIONS/INTERPRETATION: We have demonstrated for the first time in a large prospective study that dietary acid load was positively associated with type 2 diabetes risk, independently of other known risk factors for diabetes. Our results need to be validated in other populations, and may lead to promotion of diets with a low acid load for the prevention of diabetes. Further research is required on the underlying mechanisms.

Effects of the comminution rate and microbial contamination of particles in the rumen on in situ estimates of protein and amino acid digestion of expeller palm kernel and rapeseed meal.

BACKGROUND: Microbial corrected effective in situ estimates of ruminal undegraded fraction (RU) and intestinal effective digestibility (IED) of dry matter (DM), crude protein (CP) and amino acids (AA) of expeller palm kernel (EPK) and rapeseed meal (RSM) were measured on three rumen- and duodenum-cannulated wethers using ¹5N labelling techniques and considering ruminal rates of comminution (k(c)) and outflow (k(p)) of particles. RESULTS: The lack of k(c) and microbial correction overestimated the RU of DM by 4.91% (EPK) and 9.88% (RSM). The lack of this correction also overestimated in both feeds the RU of CP, individual and total (TAA) AA as well as the IED of DM, CP, TAA and most AA. RU estimates were higher for CP than for TAA, but the opposite was observed for IED. The intestinal digested fraction was higher for CP than for TAA: 17.4% (EPK) and 13.8% (RSM). Digestion led to large changes in the essential AA profile in both feeds. CONCLUSION: The lack of k(c) and microbial correction as well as CP-based results leads to considerable overestimations in the protein use of both feeds. Digestion aggravates the lysine deficiency of EPK but has global positive effects in the absorbed profile of RSM.

Associations between dairy protein intake and body weight and risk markers of diabetes and CVD during weight maintenance.

Dairy products have previously been reported to be associated with beneficial effects on body weight and metabolic risk markers. Moreover, primary data from the Diet, Obesity and Genes (DiOGenes) study indicate a weight-maintaining effect of a high-protein-low-glycaemic index diet. The objective of the present study was to examine putative associations between consumption of dairy proteins and changes in body weight and metabolic risk markers after weight loss in obese and overweight adults. Results were based on secondary analyses of data obtained from overweight and obese adults who completed the DiOGenes study. The study consisted of an 8-week weight-loss phase and a 6-month weight-maintenance (WM) phase, where the subjects were given five different diets varying in protein content and glycaemic index. In the present study, data obtained from all the subjects were pooled. Dairy protein intake was estimated from 3 d dietary records at two time points (week 4 and week 26) during the WM phase. Body weight and metabolic risk markers were determined at baseline (week -9 to -11) and before and at the end of the WM phase (week 0 and week 26). Overall, no significant associations were found between consumption of dairy proteins and changes in body weight and metabolic risk markers. However, dairy protein intake tended to be negatively associated with body weight gain (P=0·08; ß=-0·17), but this was not persistent when controlled for total protein intake, which indicates that dairy protein adds no additional effect to the effect of total protein. Therefore, the present study does not report that dairy proteins are more favourable than other proteins for body weight regulation.

Quality assurance issues in the use of dietary supplements, with special reference to protein supplements.

The use of dietary supplements is widespread in the general population, in athletes and recreational exercisers, and in military personnel. A wide array of supplements is available, but protein-containing products are consistently among the most popular, especially among those who engage in resistance training. There are significant risks associated with the use of unregulated dietary supplements. Risks include the absence of active ingredients, the presence of harmful substances (including microbiological agents and foreign objects), the presence of toxic agents, and the presence of potentially dangerous prescription-only pharmaceuticals. There is ample evidence of athletes who have failed doping tests because of the use of dietary supplements. There is also growing evidence of risks to health and of serious adverse events, including a small number of fatalities, as a result of supplement use. The risk associated with the use of protein powders produced by major manufacturers is probably low, and the risk can be further reduced by using only products that have been tested under one of the recognized supplement quality assurance programs that operate in various countries. Nevertheless, a small risk remains, and athletes, soldiers, and other consumers should conduct a cost-benefit analysis before using any dietary supplements.

Assessment of the respiratory sensitization potential of proteins using an enhanced mouse intranasal test (MINT).

There remains a need for a simple and predictive animal model to identify potential respiratory sensitizers. The mouse intranasal test (MINT) was developed to assess the relative allergic potential of detergent enzymes, however, the experimental endpoints were limited to evaluation of antibody levels. The present study was designed to evaluate additional endpoints (serum and allergic antibody levels, pulmonary inflammation and airway hyperresponsiveness (AHR)) to determine their value in improving the predictive accuracy of the MINT. BDF1 mice were intranasally instilled on days 1, 3, 10, 17 and 24 with subtilisin, ovalbumin, betalactoglobulin, mouse serum albumin or keyhole limpet hemocyanin; challenged with aerosolized methacholine or the sensitizing protein on day 29 to assess AHR, and sacrificed on day 29 or 30. Under the conditions of this study, evaluation of AHR did not improve the predictive power of this experimental model. Allergic antibody responses and IgG isotype characterization proved to be the most sensitive and reliable indicators of the protein allergenic potential with BAL responses providing additional insight. These data highlight that the evaluation of the respiratory sensitization potential of proteins can be best informed when multiple parameters are evaluated and that further improvements and refinements of the assay are necessary.

Single-cell protein as an alternative food for zebrafish, Danio rerio: a toxicological assessment.

Single-cell protein (SCP) refers to the dried cells of microorganisms. The aim of this research was to evaluate the nutrional characteristics and possible toxic effects of the SCP of Trichoderma harzianum. First, T. harzianum was grown on whey filtrate agar medium and the obtained SCP was analysed. It was rich in both total protein (34.21%) and ash (4.78%). Furthermore, the biomass contained all the essential amino acids, and the amino acid concentrations were very close to the FAO reference protein levels. Second, we exposed zebrafish (Danio rerio) embryos to diluted SCP at various concentrations for 96 hours postfertilization (hpf). Compared with the control group, we did not observe any developmental abnormalities, delayed hatching, and lethal effects on zebrafish embryos (96 hpf) found in the SCP group. To test diet effects on spawning success and growth of embryos, adult zebrafish were fed on SCP and flake feed diets for 10 weeks. The number of laid eggs, wet weight and diameter of eggs, and the percentages of hatched eggs from fish fed the flake diet and SCP diet were not significantly different from each other. Also, larval length and weight were not significantly affected by diets. Finally, SCP did not cause any toxic effect on zebrafish adults and their offsprings and could be useful as fish food or food additive.