Food allergens: threshold levels and methodologies for risk management

Food allergies and allergen management are important problems of the public health and food industry. The idea of determining allergen concentrations in food ingredients and food products that are capable of causing severe allergic reactions is of great interest for regulatory bodies as well as consumer associations and the industry all over the world. In this connection, scientists proposed different approaches to determining the basis for assessment of severity of risks of food allergens for health of patients suffering from food allergy similar to methods of risk assessment for other hazards associated with food products (for example, chemical, microbiological). To assess risk of allergens, three different approaches were proposed: i) traditional risk assessment using the no observed adverse effect level (NOAEL)) and uncertainty factors; (ii) approach based on the benchmark dose (BMD)) and margin of exposure (MoE)); and (iii) probability models. These approaches can be used in risk management in food production and in the development of warning marking about the presence of allergens. The reliability of risk assessment will depend on a type, quality and quantity of data used for determining both population threshold levels (or threshold distributions) and an impact of an allergenic product/ingredient on a particular individual.

Using Metabolite Data to Develop Patient Centric Specification for Amide Impurity in Vildagliptin Tablets

Many specified impurities in vildagliptin's finished product have been disclosed in the literature that are above their qualification threshold. We used the impurity B (amide impurity) as a case example to explore whether existing literature can be leveraged to determine the safe level of impurity and thereby develop a patient-centric specification (PCS) for impurities. No-observed-adverse-effect level (NOAEL) was derived from rate metabolism information and converted to human equivalent dose (HED). The HED was estimated as 6.5 mg/day. The high qualification levels are supported by repeat dose toxicity studies performed in rats, mice and dogs. Maximum theoretical amount (MTA) was correlated with the maximum observed amount (MOA) to verify whether the exposure was due to impurity and/or metabolite. MOA/MTA was found ≥1 suggesting that metabolism contributed to the amount excreted in feces and therefore could be used to further justify a higher specification limit than the usual one of ≤0.5%. Quite often the drug metabolism and degradation pathways overlap, resulting in the formation of identical constituents. Therefore, metabolism data can be leveraged for deriving safe levels of degradation impurities and develop PCS for impurities.

Alteration of Extracellular Matrix Components in the Anterior Pituitary Gland of Neonatal Rats Induced by a Maternal Bisphenol A Diet during Pregnancy

The extracellular matrix (ECM) plays crucial roles in the anterior pituitary gland via the mechanism of cell–ECM interaction. Since bisphenol A (BPA), a well-known endocrine disruptor, can cross through the placenta from mother to fetus and bind with estrogen receptors, cell populations in the neonatal anterior pituitary gland could be the target cells affected by this chemical. The present study treated maternal rats with 5000 µg/kg body weight of BPA daily throughout the pregnancy period and then investigated the changes in ECM-producing cells, i.e., pericytes and folliculostellate (FS) cells, including their ECM production in the neonatal anterior pituitary at Day 1. We found that pericytes and their collagen synthesis reduced, consistent with the increase in the number of FS cells that expressed several ECM regulators—matrix metalloproteinase (MMP) 9 and the tissue inhibitors of metalloproteinase (TIMP) family. The relative MMP9/TIMP1 ratio was extremely high, indicating that the control of ECM homeostasis was unbalanced. Moreover, transmission electron microscopy showed the unorganized cell cluster in the BPA-treated group. This study revealed that although the mother received BPA at the “no observed adverse effect” level, alterations in ECM-producing cells as well as collagen and the related ECM balancing genes occurred in the neonatal anterior pituitary gland.

Safety Evaluation for Restorin® NMN, a NAD+ Precursor

NAD+ is an abundant molecule in the body and vital to all living cells. NAD+ levels decline with age, and this decline correlates with age-related diseases. Therefore, sustaining NAD+ levels offers potential benefits to healthspan and longevity. Here we conducted toxicity studies to evaluate the safety of Restorin® NMN, a high purity form of the direct NAD+ precursor, β-nicotinamide mononucleotide (NMN). Based on the preliminary toxicity study and a 14-days repeated dose toxicity study at a higher dose level exposure, Restorin® NMN was administered orally to Sprague-Dawley rats for 91 days followed by a 14-days recovery period. The oral doses of 500, 1,000, and 2000 mg/kg/day were compared. There were no test item-related findings that could be considered adverse events in animals dosed at 500 mg/kg/day. The findings in the Restorin® NMN high dose group (2000 mg/kg/day) were similar to the reference item (Nicotinamide Riboside Chloride) dosed at 1740 mg/kg/day: reduced body weight, reductions in body weight gains, and diminished food consumption. In conclusion, the No-Observed-Adverse-Effect-Level (NOAEL) for Restorin® NMN is 1,000 mg/kg/day in female rats and 500 mg/kg/day in male rats, and the Low-Observed-Adverse-Effect-Level (LOAEL) for Resotrin® NMN is 2000 mg/kg/day.

Current Trends of Practices in Nonclinical Toxicology: An Industry Survey

The growth in drug development over the past years reflects significant advancements in basic sciences and a greater understanding of molecular pathways of disease. Benchmarking industry practices has been important to enable a critical reflection on the path to evolve pharmaceutical testing, and the outcome of past industry surveys has had some impact on best practices in testing. A survey was provided to members of SPS, ACT, and STP. The survey consisted of 37 questions and was provided to 2550 participants with a response rate of 24%. Most respondents (∼75%) came from the US and Europe. The survey encompassed multiple topics encountered in nonclinical testing of pharmaceuticals. The most frequent target indications were oncology (69%), inflammation (55%), neurology/psychiatry/pain (46%), cardiovascular (44%), and metabolic diseases (39%). The most frequent drug-induced toxicology issues confronted were hepatic, hematopoietic, and gastrointestinal. Toxicological effects that impacted the no observed adverse effect level (NOAEL) were most frequently based on histopathology findings. The survey comprised topics encountered in the use of biomarkers in nonclinical safety assessment, most commonly those used to assess inflammation, cardiac/vascular, renal, and hepatic toxicity as well as common practices related to the assessment of endocrine effects, carcinogenicity, genotoxicity, juvenile and male-mediated developmental and female reproductive toxicity. The survey explored the impact of regulatory meetings on program design, application of the 3 Rs, and reasons for program delays. Overall, the survey results provide a broad perspective of current practices based on the experience of the scientific community engaged in nonclinical safety assessment.

Safety Assessment of TGT Primaage using Wistar Rats through Oral Gavage Administration

TGT Primaage is one of the astonishing extracts, obtained from a combination of Moringa oleifera and Centella asiatica. At present, there is no finding reported regardin g the repeated exposure of this extract. This study investigates the No Observed Adverse Effect Level (NOAEL) and effects of repeated-dose administration of Astragalin and Isoquercetin (components of interest) present in TGT Primaage on Wistar rats. Rats were divided into 3 treatment and a control group (10 rats/sex/group). To assess reversibility, persistence, or delayed effect, additional control and high dose groups were treated similarly and observed further without any treatment. TGT Primaage was administered orally, through gavage for 90 days, at 0, 250, 500, and 1000 mg/kg body weight/day. No mortality, morbidity, and clinical sign of toxicity was observed. Abnormality related to neurological and functional parameters was not seen. No change in body weight and food consumption was observed. Treatment did not lead to any adverse effect in clinical pathology parameters and organ weights. TGT Primaage did not alter morphological and histopathological characteristics of organs. From these results, it is evident that TGT Primaage appears to be safe and devoid of any toxicity. The No Observed Adverse Effect Level (NOAEL) of TGT Primaage for both sexes were found to be 1000 mg/kg body weight/day

Pharmacokinetics and Disposition of Contezolid in Humans—Resolution of a Disproportionate Human Metabolite for Clinical Development

Contezolid (MRX-I), a novel oxazolidinone antibiotic, was recently approved for the treatment of serious Gram-positive infections. The pharmacokinetics and disposition of [ 14 C]contezolid were investigated in a single-dose human mass balance study. Cross-species comparison of plasma exposure for contezolid and metabolites was performed, and the safety of the disproportionate metabolite in human was evaluated with additional nonclinical studies. After an oral administration of 99.1 μCi/602 mg dose of [ 14 C]contezolid, approximately 91.5% of the radioactivity was recovered in 0–168 h postdose, mainly in urine and followed by feces. The principal metabolic pathway of contezolid in human comprised an oxidative ring opening of 2,3-dihydropyridin-4-one fragment into polar metabolites MRX445-1 and MRX459, with recovery of approximately 48% and 15% of the dose, respectively, in urine and feces. Contezolid, MRX445-1, and MRX459 accounted for 68.0%, 19.5%, and 4.84% of the plasma exposure of the total radioactivity, respectively. Metabolites MRX445-1 and MRX459 were observed in disproportionately higher amounts in human plasma as compared to that rat or dog, the rodent and nonrodent species used for the general nonclinical safety assessment of this molecule. This discrepancy was resolved with additional nonclinical studies, wherein the primary metabolite, MRX445-1, was further characterized. The no observed adverse effect level (NOAEL) of MRX445-1 was determined as 360 mg/kg/day in 14-day repeat-dose test in pregnant and non-pregnant SD rats. Furthermore, MRX445-1 exhibited no antibacterial activity in vitro. Thus, MRX445-1 is not expected to exert clinically relevant pharmacology and toxicity.

Humidifier disinfectant, sodium dichloroisocyanurate (NaDCC): assessment of respiratory effects to protect workers’ health

In South Korea, it has been found that biocides used to control and eliminate harmful organisms are used as humidifier disinfectants and cause lung disease in users. Hence, efforts have been focused on studying the toxicity of biocides in workers who handle them. The purpose of this study was to evaluate the effects of inhalation exposure to sodium dichloroisocyanurate (NaDCC) to protect the health of workers handling NaDCC. F344 rats were exposed to 0.8-, 4-, and 20-mg/m3 of NaDCC for 6 h per day, 5 days per week for 14 days, and the recovery period after exposure was 14 days. In the 20-mg/m3-exposure group, we observed a decrease in food intake in females, a weight loss in males, and a decrease in partially active thromboplastin time in males and females 2 weeks after exposure. We noted a decrease in white blood cells in males in the 4- and 20-mg/m3-exposed groups. Both males and females in the 20-mg/m3 group and males in the 4-mg/m3 group showed irritation in the larynx related to test substance exposure. However, these findings were not observed in the recovery group. The main target organs affected by repeated 2-week inhalation exposure to NaDCC were the nasal cavity and larynx in the upper respiratory tract. The No Observed Adverse Effect Level (NOAEL) was considered to be 0.8 mg/m3 because effects related to NaDCC exposure were observed even at of 4 mg/m3, and these effects were found to be reversible.

Tolerable amounts of amino acids for human supplementation: summary and lessons from published peer-reviewed studies

Amino acid supplementation may be indicated to correct for insufficient amino acid intake in healthy individuals, and in specific physiological or pathophysiological situations. However, there is a concern to not supplement beyond the tolerable upper intake level (UL) by determining parameters of no-observed-adverse-effect level (NOAEL) or lowest-observed-adverse-effect level (LOAEL) for each amino acid. Since the NOAEL and LOAEL values are at least one order of magnitude different when comparing the values obtained in rats and humans, the aim of this review is to evaluate to what extent the amino acid UL measured in the rat model, when referenced to the dietary usual consumption (UC) and dietary requirement (RQ) for indispensable amino acids, may be used as an approximation of the UL in humans. This review then compares the ratios of the NOAEL or LOAEL over UC and RQ in the rat model with the same ratios calculated in humans for the nine amino acids (arginine, serine, glycine, histidine, leucine, lysine, methionine, phenylalanine, and tryptophan) for which this comparison can be done. From the calculations made, it appears that for these 9 amino acids, the calculated ratios for rats and humans, although rather different for several amino acids, remains for all of them in the same order of magnitude. For tryptophan, tyrosine, and valine, the ratios calculated in rats are markedly different according to the sex of animals, raising the view that it may be also the case in humans.