Toxicological and safety evaluations of Weissella cibaria strain CMU in animal toxicity and genotoxicity

Weissella cibaria belongs to the Lactobacillaceae family and has been isolated from traditional fermented foods and saliva of children with good oral health. Previous investigations have shown that W. cibaria CMU (Chonnam Medical University) is expected to be safe based on results of in silico and in vitro analyses. However, there is a lack of studies assessing its safety in vivo. A toxicological safety evaluation of W. cibaria CMU was performed using an acute oral safety study in rats, a 14-day oral range finding study, a subsequent 13-week oral toxicity study in rats and a genetic toxicity battery (in vitro bacterial reverse mutation, in vitro chromosome aberration in Chinese Hamster Ovary cells and in vivo micronucleus study in mice). The results of the studies in rats showed that the acute lethal dose of W. cibaria CMU is > 5000 mg/kg body weight (bw)/day (1.8 × 109 CFU/kg bw/day) and the 14-day or 13-week no observed adverse effect level (NOAEL) is 5000 mg/kg bw/day (1.8 × 109 CFU/kg bw/day), the highest dose administered. W. cibaria CMU was non-mutagenic in the bacterial reverse mutation test and non-clastogenic or aneugenic in vitro and in vivo. In conclusion, the toxicological studies performed demonstrated W. cibaria CMU to be a safe strain to consume. This study is the first study examining the potential of a W. cibaria strain to cause genetic toxicity and subchronic toxicity in rats according to the Organization for Economic Cooperation and Development guidelines.

Calibration of Onboard Equipment for Measuring Pseudo-Range Between Spacecraft to Improve the Accuracy of Determining Their Time Scales Discrepancy

Technologies for range-finding measurements between spacecraft are increasingly used in achieving the targets of modern spacecraft. The stability of the systematic error is one of the main factors affecting the accuracy of achieving a target. This determines the requirement to ensure the stability of the systematic error at the level of several centimeters in the presence of destabilizing factors and a tendency to increase the spacecrafts active life in orbit. Apart from searching for methods implemented directly in the onboard equipment, it is advisable to consider mathematical methods that are applicable at the stage of processing measurements when achieving the spacecraft targets. The paper describes the technology for determining and accounting for calibration corrections for spacecraft onboard radio-technical equipment intended for range-finding measurements and exchanging information between spacecraft. This technology is based on statistical processing of residuals of linear combinations of measured parameters relative to their high-precision calculated analogs, obtained using a posteriori ephemeris-time information. The use of this technology makes it possible to compensate for the change in the constant component of the systematic measurement error at the stage of spacecraft operation in orbit.

Postnatal Hepatobiliary and Gastrointestinal Systems Development and Impact on ADME

Toxicity can result from variable target organ sensitivity and exposure based on postnatal development. Changes in the gastrointestinal tract (GIT) in neonates are driven by initial enteral feedings. These are important for nutrient uptake as well as drug disposition and include motility, expansion of enzyme and transporter function, permeability, intestinal microbiome, and species-specific maturation. Some aspects of GIT function do not mature until driven by increased dietary complexity. As with the GIT, postnatal hepatic maturation in the rat includes a variety of anatomic and functional changes that include refinements in the activities or expression of drug transporters and drug-metabolizing enzymes. These changes may impact rodent pharmacokinetics, nonclinical toxicity profiles, and estimation of safe pediatric doses. Pilot or dose range finding studies can help characterize and mitigate toxicity related to drug disposition, especially in juvenile rodents. Interpretation of developmental toxicity requires knowledge of developing systems in humans and nonclinical models.

Development of a novel, pan-variant aerosol intervention for COVID-19

To develop a universal strategy to block SARS-CoV-2 cellular entry and infection represents a central aim for effective COVID-19 therapy. The growing impact of emerging variants of concern increases the urgency for development of effective interventions. Since ACE2 is the critical SARS-CoV-2 receptor and all tested variants bind to ACE2, some even at much increased affinity (see accompanying paper), we hypothesized that aerosol administration of clinical grade soluble human recombinant ACE2 (APN01) will neutralize SARS-CoV-2 in the airways, limit spread of infection in the lung and mitigate lung damage caused by deregulated signaling in the renin-angiotensin (RAS) and Kinin pathways. Here we show that intranasal administration of APN01 in a mouse model of SARS-CoV-2 infection dramatically reduced weight loss and prevented animal death. As a prerequisite to a clinical trial, we evaluated both virus binding activity and enzymatic activity for cleavage of Ang II following aerosolization. We report successful aerosolization for APN01, retaining viral binding as well as catalytic RAS activity. Dose range-finding and IND-enabling repeat-dose aerosol toxicology testing were conducted in dogs. Twice daily aerosol administration for two weeks at the maximum feasible concentration revealed no notable toxicities. Based on these results, a Phase I clinical trial in healthy volunteers can now be initiated, with subsequent Phase II testing in individuals with SARS-CoV-2 infection. This strategy could be used to develop a viable and rapidly actionable therapy to prevent and treat COVID-19, against all current and future SARS-CoV-2 variants.

Preclinical Characterization of a Novel Anti-Cancer PD-L1 Inhibitor RPH-120

RPH-120 is a novel fully human anti-PD-L1 IgG1 monoclonal antibody with specifically designed Asn300Ala mutation in Fc fragment. Surface plasmon resonance assay showed that affinity of the RPH-120 to the dimeric form of human PD-L1-Fc fusion protein was much higher than affinity to the monomeric His-tagged PD-L1. Further binding studies demonstrated that RPH-120 is able to bind to human and monkey but not mouse PD-L1. Tissue cross-reactivity study showed good comparability of human and Cynomolgus monkeys tissue staining. Bioactivity was assessed using mixed lymphocyte reaction assay. This study revealed that RPH-120 was able to activate T cells preventing PD1/PD-L1 interaction. Antitumor efficacy was analyzed in HCC-827 lung cancer xenografts in humanized CD34+ mice at three dosage levels: 20, 80, and 200 mg/kg. RPH-120 demonstrated significant tumor growth inhibition, and this inhibition was comparable to that of atezolizumab. In a single dose toxicity, toxicokinetic and dose range finding study performed in Cynomolgus monkeys, RPH-120 was administered via intravenous (IV) bolus or 60-min IV infusion, followed by 8-weeks recovery period. An acceptable toxicokinetic profile was demonstrated and administration at doses of up to 200 mg/kg was well tolerated by all animals. In conclusion, RPH-120 revealed promising in vitro and in vivo activity and safety. RPH-120 is a potent anti-PD-L1 drug candidate for cancer immunotherapy.

In vitro acute inhalation toxicity for TiO2 (GST) using 3D human tissue model (EpiAirwayTM)

The present study was performed to screen in vitro potential acute inhalation toxicity using an EpiAirwayTM tissue model (human tracheal/bronchial tissue) for the nano-sized titanium dioxide, GST manufactured as a photocatalyst through of sludge recycling and to compare with P-25 a commercialized photocatalytic material. According to the protocol provided by in vitro tissue manufacturer, the GST was exposure to the tissue for 3 hours in 450, 500, 650, 850 mg/mL concentration after preliminary dose range finding study and then tissue viability (%, IC75) was calculated using the MTT assay. Besides, the histopathological observation was performed to compare to the MTT assay. As a result of study, IC75 could not be confirmed at 850 mg/mL in both GST and P-25 and the grade was confirmed to be IC75> 600 mg/mL in vitro model tissue category. Therefore, it was considered that the GHS category could be classified as ‘No classification’ in screening method for potential acute inhalation toxicity. Also, not the morphological effects of epithelial cells in tissue model were observed compared with the vehicle control and histological findings were similar to the results of MTT Viability assay. Based on these results, the potential acute inhalation toxicity for GST produced through sludge recycling using in vitro tissue model inhalation toxicity showed that it could be non-hazardous substance. However, further study (in vivo study, etc.) is thought to be needed to ascertain whether GST is a toxic effect or safe.

TOXICITY EFFECT OF RADIOGRAPHIC DEVELOPER EFFLUENT ON GIANT AFRICAN SNAIL (Achatina fulica)

Background: The decline in the population of snails, a source of protein of people living in the high forest zone due to environmental pollution and the hazard caused by the disposal of radiographic developer effluent into streams, bushes or forests and public sewer systems makes the assessment of the effect on giant African snails (Achatina fulica) from environmental pollution due to radiographic developer effluent very important. Materials and Methods: Ninety 5 months old, 12 months old and 24 months old giant African snails were randomly divided into 6 groups of 15 snails for each age group based on the dose of developer effluent to be administered. One group from each age group was designated the control and the remaining, the experimental group. Range finding test was performed at effluent concentrations of 100 %, 50 %, 25 %, 12.5 %, 6.25 %, 3.125 %, 1.6 % and 0 % (control) in 150 ml of distilled water. The effluent solution was administered on the feed and soil of the experimental snails only. Results: Behavioural changes occurred between 0.2 – 1.0 % concentration and mortality at 24 – 96 hours exposure to the effluent solutions. The percentage (%) mortality of the giant African snails increased as the effluent concentration increased from 0.2 - 1.0 % and at an increased exposure time of 24 – 96 hours. The estimated 96 hours LD for the 5, 12 and 24 months old giant African snails were 0.20 - 0.23, 0.23 - 0.25 and 0.30 - 0.26 respectively. Conclusion: Radiographic developer effluent is harmful to the giant African snails, with the % mortality increasing with an increase in concentration and exposure time to the developer effluent. Legislation is recommended to ensure the safe disposal of radiographic developer effluents into the Nigerian environment considering the importance of giant African snails (Achatina fulica) to the ecosystem and the economy.

Fermotein Does Not Exert Genotoxic Effects in Bacterial Reverse Mutation and in Vitro Mammalian Cell Micronucleus Tests

Aim: Fermotein is an innovative single-cell protein obtained from fermentation of the filamentous fungus Rhizomucor pusillus. Like other filamentous fungi, a lack of information on this species exists to assess its safety for human consumption. The capability to induce gene mutations or structural and numerical chromosomal aberrations of this fungus and derived products has never been studied before. The objective of the current study was to investigate the genotoxic effects of Fermotein using a bacterial reverse mutation test and an in vitro mammalian cell micronucleus test. Methodology: The bacterial reverse mutation test and in vitro mammalian cell micronucleus test were performed in accordance with GLP and concurrent OECD guidelines. Dose-range finding tests were used to select appropriate doses of Fermotein Dry. The highest doses in the genotoxicity experiments were determined by the solubility of the mycoprotein. Results: The bacterial reverse mutation test and in vitro mammalian cell micronucleus test were performed in accordance with GLP and concurrent OECD guidelines. Dose-range finding tests were used to select appropriate doses of Fermotein Dry. The highest doses in the genotoxicity experiments were determined by the solubility of the mycoprotein. Conclusion: No safety concerns regarding genotoxicity were identified for Fermotein and no further in vivo genotoxicity testing is required. Information from the current study contributes to the body of evidence for a novel food authorisation of Fermotein in the EU and a GRAS notification in the US.