Introduction For in vivo inhalation studies, aerosol dosimetry links aerosol exposure and deposited dose within the respiratory tract. Aerosol dosimetry programs like the Multiple Path Particle Deposition model utilize respiratory tract geometry, respiratory physiology, and aerosol properties to predict particle deposition within the respiratory tract. A challenge to wider use of these dosimetry programs for in vivo inhalation studies is the lack of species-specific or strain specific respiratory tract anatomy, and in some cases, strain specific respiratory physiology data. The objective of this work was to develop aerosol dosimetry predictions for the in vivo human disease models of chronic obstructive pulmonary disease (COPD; C57BL/6 mice) cardiovascular disease (CVD; ApoE-/- mice), and lung cancer (AJ mice) using the Multiple Path Particle Deposition dosimetry model. Methods Microcomputed tomography derived tracheobronchial geometry data were combined with available pulmonary geometry data for C57BL/6, ApoE-/-, and AJ mice and incorporated into the Multiple Path Particle Deposition dosimetry model. Mouse strain specific respiratory physiology literature values were used as input into the Multiple Path Particle Deposition dosimetry model. Results The resulting particle deposition predictions compared well with the very limited strain specific experimental particle deposition data. Since multiple tracheobronchial geometries and thus pulmonary anatomies were used for C57BL/6 and ApoE-/- mice, an estimate of intrastrain variability in predicted particle deposition was obtained. Discussion and Conclusions The intrastrain variability in predicted particle deposition for C57BL/6 and ApoE-/- mice was always smaller in the tracheobronchial compared to pulmonary airways. The differences in reported respiratory physiology values for C57BL/6 mice resulted in greater intrastrain variability in predicted particle deposition than observed with the different tracheobronchial geometries and pulmonary anatomies. These mouse strain specific aerosol dosimetry predictions can provide insight into the delivered dose to specific respiratory tract regions that can be correlated with in vivo endpoints.
Introduction: Intestinal colonisation of Salmonella is a major concern in the poultry industry, and a low dose of the high-purity synthetic capsaicin analogue phenylcapsaicin (PheCap) has the potential to be a phytobiotic alternative to antibiotics in reducing floor Salmonella in commercial broiler chicken houses. In this study we present the first safety assessment of PheCap at doses relevant for the poultry industry. Methods: In a completely randomized block design, Ross 308 male broilers were offered feed containing 0, 10, 15, or 150 mg PheCap/kg. Growth rates, mortality, haematology, clinical chemistry, foot pad lesions, litter quality and gross pathological examination of organs and tissues were evaluated for signs of toxicity over a two-phase, 35-day growth period. Results: No differences in feed intake and broiler growth were found, with broilers in the control group having the highest mortality. There was a statistically significant increase in the European Production Efficiency Factor (EPEF) for the 10 (p = 0.02) and 15 mg PheCap/kg feed (p = 0.003) treatment doses. No dose dependent adverse effects were found for any of the treatment doses. The No Observed Adverse Effect Level (NOAEL) of PheCap is probably higher than that of the highest weekly averaged daily intake of 36.3 mg/kg BW/day observed in the present study. Conclusions: The inclusion of PheCap in broiler feed at doses relevant for the commercial poultry industry is assumed not have any negative effects on broiler health.
Introduction Bis-octanoyl (R)-1,3-butanediol (BO-BD) is a novel, palatable ketone ester that, when consumed, is hydrolyzed in the gastrointestinal tract into octanoic acid (OCT) and (R)-1,3-butanediol (BDO) which are subsequently metabolized into beta-hydroxybutyrate (BHB). Metabolism of BO-BD is hypothesized to be similar to bis-hexanoyl (R)-1,3-butanediol (BH-BD), apart from release of octanoic acid instead of hexanoic acid (HEX). Methods As part of the safety assessment for BO-BD a randomized, cross-over, open-label study in middle-aged, healthy adults ( n = 12) was undertaken to provide a qualitative comparison of plasma BHB, OCT, HEX and BDO concentrations for 8 h following consumption of 12.5 or 25 g of BO-BD and 12.5 g of BH-BD. Results All study products increased plasma BHB and BDO up to 4 h post-consumption. BH-BD increased HEX, whereas BO-BD increased OCT. All kinetic parameters for BHB and BDO were similar between 12.5 g servings of BH-BD and BO-BD while C max and AUC for OCT were higher following 12. 5 g servings of BO-BD as compared to HEX with 12.5 g of BH-BD. All metabolites returned to baseline by 8 h post-consumption. BHB, BDO and OCT C max and AUC were increased with serving size of BO-BD from 12.5 to 25 g. Sensory acceptability scores of BO-BD were significantly higher than for BH-BD. An in vitro hydrolysis experiment using human blood plasma further confirmed that plasma esterases possess the ability to break down the novel ketone esters into BDO, and OCT or HEX. Discussion The two novel ketone ester molecules exhibit similar metabolic breakdown to BHB and BDO and result in transiently higher concentrations of the plasma fatty acids, OCT and HEX, in vivo. Conclusions Given the similar ketone delivery with greater acceptability, BO-BD may offer a more broadly translatable tool to induce physiologic ketosis than BH-BD.
Naturally sweet proteins have no glycemic effect and offer a fundamentally new approach to sweetness and health for individuals seeking to reduce their added sugar intake. However, unlike many commercial sweeteners, little research has been performed on the potential safety implications of adding these uniquely sweet proteins to food and beverages. In this study, a naturally sweet protein found in the West African Oubli plant ( Pentadiplandra brazzeana), referred to as Oubli fruit sweet protein or brazzein, was expressed in Komagataella phaffii (formerly Pichia pastoris) and produced via precision fermentation, and a safety and risk assessment was undertaken for its use as a sweetener in food and beverages. Potential consumption levels of brazzein were estimated to be 3 mg/kg body weight/day based on the National Health and Nutrition Examination Survey. The safety of brazzein derived from K. phaffii was evaluated through in silico allergenicity, in vitro genotoxicity (reverse mutation and mammalian micronucleus assays), and a 90-day dietary oral toxicity study in rats. There was no indication of allergenicity in the in silico analyses. Brazzein was non-genotoxic in the in vitro assays and showed no adverse effects in the 90-day oral toxicity study up to the highest dose tested, where the no-observed-adverse-effect level (NOAEL) was 978 and 985 mg/kg body weight/day in males and females, respectively. The totality of evidence in the in silico allergenicity, in vitro genotoxicity, and 90-day dietary toxicity studies demonstrates that brazzein derived from K. phaffii is considered safe for use as a sweetener in food and beverages.
Background Alternansucrase is a glucansucrase enzyme that mainly functions in synthesis of glucan-like polysaccharides and can be used for production of novel oligosaccharides and polysaccharides having low glycemic index and prebiotics properties which makes them ideal candidates as dietary fibers and food. From a regulatory perspective, it is necessary to prove the safety of alternansucrase before it can be used in any application as it is a novel enzyme and has not been historically used in food processing. Objectives Alternansucrase obtained from Escherichia coli was subjected to toxicological tests to determine its safety for use in various industrial applications. Design Toxicity studies were conducted at acute oral and repeated sub-chronic (14 days and 90 days) levels in rats following the OECD guidelines. The genotoxicity studies were conducted using the bacterial reverse mutation test as well as in vitro mammalian cell micronucleus test as per the OECD guidelines. Results Alternansucrase did not induce any clinical abnormalities or mortality in rats at the dose level of 2000 mg/kg of body weight in the acute oral toxicity test. A 90-day sub chronic repeated dose oral toxicity study with alternansucrase at and up to dose of 1000 mg TOS/kg of body weight did not show any treatment-related significant toxicological effects on body weight, food consumption, organ weights, hematological and clinical chemistry, or histopathology parameters. Alternansucrase was found to be non-mutagenic up to 5000 µg TOS/plate concentration in the bacterial reverse mutation test. Alternansucrase was determined to be non-clastogenic and non-aneugenic up to the test concentration of 1250 µg TOS/mL during the in vitro mammalian cell micronucleus test. Conclusion The lethal dose (LD 50 ) based on this study is greater than 2000 mg/kg body weight, which falls into the category 5 criteria of Globally Harmonized System (GHS). No-Observed-Adverse-Effect-Level (NOAEL) was concluded to be greater than 1000 mg TOS/kg per day. The studies taken together substantiate the safety of alternansucrase enzyme in various food and associated industries. The present study paves a future for safe use of alternansucrase in varied industrial applications.
