Human Therapeutic Dose Research Articles

ACUTE AND SUB-ACUTE TOXICOLOGICAL STUDY OF VANGA BHASMA

Introduction: Vanga is a dhatu, that has been used externally since the Samhita period. During the rasa shastra era, vanga was utilized internally for Prameha, (urinary disorder ) Medoroga(diseases of medadhatu – fat tis-sue), Kapha Vikaras(diseases of kapha-bodily constitution ), and other purposes after Bhasmikara-na.(preaparation of Bhasma - medicine ) Objective: Evaluate Acute and Sub-acute toxicity of Vanga Bhasma. Materials &Methods: The acute and sub-acute toxicity studies of Vanga Bhasma were carried out on Wistar Albino rats using 425 and 407 OECD guidelines, respectively. Acute oral toxicity study of the test drug was car-ried out at the limit dose of 2000 mg/kg orally in rats. In a sub-acute toxicity study, Vanga bhasma was adminis-tered to rats for 28 consecutive days at doses of 22.5(TED-therapeutic equivalent dose), 112.5(TEDX5), and 225 mg/kg(TEDX10). The effects of the drug were assessed on haematological, biochemical, histological, and pon-deral parameters. Results: Acute toxicity: the study showed the LD 50 value of Vanga Bhasma is greater than 2000mg/kg. Sub-acute toxicity: this study did not produce any signs or symptoms of toxicity at TED, TEDX5, and TEDX10. Conclusion: The single dose of 2000mg/kg body weight evaluated by acute toxicity study is proved to be non-toxic. Overall analysis reveals that test drug vanga bhasma is very well tolerated at rat human therapeutic equivalent dose and multiples of it. Therefore, Vanga bhasma, prepared and administered in accord-ance with customary protocols, is safe to consume at therapeutic dose levels.

Revealing the impact of Rapamycin on the virulence factors of the Candida haemulonii complex

The incidence of invasive fungal infections caused by Candida species is increasing, particularly in immunocompromised individuals. This increasing incidence poses a dual challenge, comprising escalating antifungal resistance and the necessity for accurate fungal identification. The Candida haemulonii complex further complicates these challenges due to limited identification tools. Like some other Candida species, infections involving this complex show resistance to multiple antifungals, requiring innovative therapeutic approaches. Rapamycin, known for its antifungal properties and immunosuppressive characteristics, was investigated against the C. haemulonii complex species. Results revealed a rapamycin minimal inhibitory concentration (MIC) range of 0.07 to >20 µM, with fungicidal effects in most strains. In vitro analyses using the rapamycin maximum plasma concentration (0.016 µM) showed reduced surface properties and decreased production of extracellular enzymes. Rapamycin also hindered biofilm formation by some strains. Even when treated at the human therapeutic dose, which is lower than the MIC, phenotypic variations in C. haemulonii were detected, hinting at the possible attenuation of some virulence factors when exposed to rapamycin.

Impact of maternal topiramate ingestion on ossification of skull and appendicular bones in rat fetuses

The skull and appendicular bones are derived from different embryological sources during their development. The impact of prenatal exposure of topiramate on ossification of these bones is not adequately studied. The goal of this study was to assess the ossification patterns of the craniofacial bones and bones of the forelimbs and hindlimbs in 20-day-old rat fetuses after maternal exposure to topiramate at doses equivalent to human therapeutic doses. Three groups of Sprague-Dawley pregnant rats were used: control, topiramate 50mg/kg/day (T50) and topiramate 100mg/kg/day (T100). Topiramate was given by oral gavage from day 6 to day19 of gestation. Ossification was evaluated in the bones of 20 days fetuses after staining with Alizarin red. Results showed a significant reduction in complete ossified centers of the metacarpal, metatarsal and craniofacial bones in topiramate-exposed fetuses at both doses when compared to the control group. Also, a significant decrease in the length of ossified part of the long bones of the forelimbs and hindlimbs in topiramate-exposed fetuses at both doses was noted when compared to the control group. Crown-rump length and fetal weight were significantly decreased in topiramate treated groups compared to the control group. In all examined groups, there was a positive correlation between the crown-rump length and the lengths of humerus and femur. No abnormalities in the ossified bones and no significant changes in their ossification pattern were observed between the treated groups. In conclusion, prenatal administration of topiramate in doses equivalent to human therapeutic doses delayed ossification and development of craniofacial and appendicular bones in rat fetuses and their effects are not dose dependent at doses investigated. The implications of these findings in women who require topiramate therapy in pregnancy merit further evaluation.

GC-MS Analysis and Toxicological Evaluation of Asparagus falcatus Linn. Extracts in Healthy Wistar Rats Using a Biochemical, Hematological and Histological Approach

Abstract: The present study evaluates the potential toxic/adverse effects of selected extracts derived from Asparagus falcatus Linn. (family; Asparagaceae) leaves via acute and sub-acute oral toxicity assessment in healthy Wistar rats. The dried powder of the leaf of A. falcatus was sequentially extracted in hexane (AFH), ethyl acetate (AFEA), n-butanol (AFNB) and water (AFW), respectively, by the Soxhlet extraction method followed by complete evaporation of the solvents. Investigations were carried out by repeated dose oral administration (daily for 28+ days) of AFH (55 mg/kg), AFEA (35 mg/kg), AFNB (75 mg/kg) and AFW (200 mg/kg) leaf extracts derived from A. falcatus in healthy Wistar rats (n = 5/sex/group). GC-MS analysis was also conducted. None of the biochemical and hematological parameters showed clinically significant changes in the sub-acute oral toxicity assessment of the selected leaf extracts at the therapeutic doses. Qualitative analysis of phytochemicals in AFH, AFEA, AFNB and AFW leaf extracts of A. falcatus revealed the absence of alkaloids, excluding thus the potential risk of pyrrolizidine alkaloids. The presence of prominent bioactive phytoconstituents identified by GC-MS analysis, including dodecanoic acid, 1,2,3-propanetriyl ester, cyclohexanol,5-methyl-2-(1-methylethyl)-(1.alpha,2.alpha,5.alpha), hexadecanoic acid, butyl ester, octadecanoic acid, ethyl ester, 3,7,11,15-tetramethyl-2-hexadecen-1-ol and hexanedioic acid bis(2-ethylhexyl)ester, further signified the medicinal importance of A. falcatus. In addition, dimethyl sulfone, 2,3-butanedioldiacetate, E-14-hexadecanal, tetradecane, octadecane, tetracosane,11-decyl, etc., were identified in abundance in the GC-MS analysis. The results might ensure the safe consumption of the plant extracts at the human equivalent therapeutic dose in healthy Wistar rats.

Preclinical Evaluation of Esomeprazole Safety and Toxicokinetics

Esomeprazole, the S-isomer of omeprazole, is a second-generation proton pump inhibitor widely used for acid-related diseases of the oesophagus, stomach, and duodenum (peptic ulcer, gastro-oesophageal reflux disease, etc.). Studies on esomeprazole safety and toxicokinetics (TK) are essential for increasing the number of modified-release esomeprazole products manufactured in Russia.The aim of the study was to compare the safety and toxicokinetics of a new esomeprazole product, 40 mg modifiedrelease capsules (Valenta Pharm JSC, Russia), and Nexium® 40 mg film-coated tablets (AstraZeneca AB, Sweden).Materials and methods. This toxicity study involved oral administration of esomeprazole 40 mg modified-release capsules (Valenta Pharm JSC, Russia) and Nexium® 40 mg film-coated tablets (AstraZeneca AB, Sweden) to 5 groups of rabbits (8 males and 8 females per group) for 28 days at a dose of 1 or 3 capsules, or tablets, corresponding to approximately 4.8 or 14.3 maximum human therapeutic doses (MHTDs), respectively. Comparisons included general toxicity, local tolerance, safety pharmacology, effects on immune system organs, reproductive toxicity, and basic TK parameters (Cmax, Tmax, AUC0-24, MRT, and T1/2).Results. No toxic effects, including local irritation and immunotoxicity, were observed for the test product. The safety pharmacology testing demonstrated the safety of repeated oral administration of the test product for the cardiovascular, excretory, respiratory systems and the liver. The test product did not affect the reproductive system of male and female rabbits. The No Observed Adverse Effect Level (NOAEL) was determined to be 14.3 MHTDs. According to the TK parameters evaluated after single and repeated oral administration, the test product and Nexium® demonstrated comparable TK profiles.Conclusions. The study demonstrated a favourable safety profile for the test product. All the test product parameters studied were comparable with those of Nexium®. Positive clinical experience with Nexium® supports the data obtained for the new esomeprazole product. Thea safety of these medicinal products may be considered similar.

High doses of rosuvastatin induce impaired branched-chain amino acid catabolism and lead to insulin resistance.

What is the central question of this study? Is there a risk of developing diabetes associated with statin treatment? What is the underlying mechanism of the increased incidence rate of new-onset diabetes in patients treated with rosuvastatin? What is the main finding and its importance? Rosuvastatin therapy reduced intraperitoneal glucose tolerance and changed the catabolism of branched-chain amino acid (BCAAs) in white adipose tissue and skeletal muscle. Protein phosphatase 2Cm knockdown completely abolished the effects of insulin and rosuvastatin on glucose absorption. This study provides mechanistic support for recent clinical data on rosuvastatin-related new-onset diabetes and underscores the logic for intervening in BCAA catabolism to prevent the harmful effects of rosuvastatin. Accumulating evidence indicates that patients treated with rosuvastatin have an increased risk of developing new-onset diabetes. However, the underlying mechanism remains unclear. In this study, we administered rosuvastatin (10mg/kg body weight) to male C57BL/6J mice for 12weeks and found that oral rosuvastatin dramatically reduced intraperitoneal glucose tolerance. Rosuvastatin-treated mice showed considerably higher serum levels of branched-chain amino acids (BCAAs) than control mice. They also showed dramatically altered expression of BCAA catabolism-related enzymes in white adipose tissue and skeletal muscle, including downregulated mRNA expression of BCAT2 and protein phosphatase 2Cm (PP2Cm) and upregulated mRNA expression of branched-chain ketoacid dehydrogenase kinase (BCKDK). The levels of BCKD in the skeletal muscle were reduced in rosuvastatin-treated mice, which was associated with lower PP2Cm protein levels and increased BCKDK levels. We also investigated the effects of rosuvastatin and insulin administration on glucose metabolism and BCAA catabolism in C2C12 myoblasts. We observed that incubation with insulin enhanced glucose uptake and facilitated BCAA catabolism in C2C12 cells, which was accompanied by elevated Akt and glycogen synthase kinase 3 β (GSK3β) phosphorylation. These effects of insulin were prevented by co-incubation of the cells with 25μM rosuvastatin. Moreover, the effects of insulin and rosuvastatin administration on glucose uptake and Akt and GSK3β signaling in C2C12 cells were abolished when PP2Cm was knocked down. Although the relevance of these data, obtained with high doses of rosuvastatin in mice, to therapeutic doses in humans remains to be elucidated, this study highlights a potential mechanism for the diabetogenic effects of rosuvastatin, and suggests that BCAA catabolism could be a pharmacological target for preventing the adverse effects of rosuvastatin.

Kefir as a therapeutic agent in clinical research: a scoping review.

Increasing research has been conducted on the role of probiotics in disease treatment. Kefir, a safe, low-cost probiotic fermented milk drink, has been investigated in many in vitro and animal studies, although parameters for human therapeutic dose or treatment time have not yet been determined. Here we perform a scoping review of clinical studies that have used kefir as a therapeutic agent, compiling the results for perspectives to support and direct further research. This review was based on Joanna Briggs Institute guidelines, including studies on the effects of kefir-fermented milk in humans. Using the term KEFIR, the main international databases were searched for studies published in English, Spanish or Portuguese until 9 March 2022. A total of 5835 articles were identified in the four databases, with forty-four eligible for analysis. The research areas were classified as metabolic syndrome and type 2 diabetes, gastrointestinal health/disorders, maternal/child health and paediatrics, dentistry, oncology, women's and geriatric health, and dermatology. The many study limitations hampered generalisation of the results. The small sample sizes, methodological variation and differences in kefir types, dosage and treatment duration prevented clear conclusions about its benefits for specific diseases. We suggest using a standard therapeutic dose of traditionally prepared kefir in millilitres according to body weight, making routine consumption more feasible. The studies showed that kefir is safe for people without serious illnesses.

Assessment of Chronic Toxicity of an Ayurvedic Herbo-Metallic Formulation Rasaraj Rasa in Wistar Rats.

This study aimed to assess the adverse effects of Rasaraj Rasa tablets after repeated oral administration for 180 days in Wistar rats. Wistar rats were divided into five groups, of which three were treated with 54, 162, and 270 mg/kg body weight of Rasaraj Rasa, respectively, which correspond to one, three, and five times the proposed human therapeutic dose, for 180 days consecutively. The fifth group (satellite) also received 270 mg/kg body weight of Rasaraj Rasa for 180 days. Body weight and food intake were measured weekly. At the end of the study, all rats were sacrificed, and their blood, serum, and organs were collected and examined using hematology, serum biochemistry, gross pathology, and histopathology tests. In contrast, the satellite group was kept for 4 weeks after treatment. No significant treatment-related toxicological findings were observed in the clinical features, body weight, laboratory findings, and pathological findings of the high-dose treated groups, when compared to those of the control group. The no-observed-adverse-effect-level for Rasaraj Rasa in Wistar rats is set at 270 mg/kg body weight.

Preclinical acute toxicity studies of the CAR technology products for malignant neoplasms therapy on the example of the «anti-HER2-CAR-T/CAR-NK»

Introduction. The Car-T-cell therapy is current and modern promising method for the oncology treatment. USA Food and Drug Sanitary Control Department confirms six drugs for cellular immunotherapy the blood oncology today. But the information about biomedical product preclinical test is absent, because used T-cells (cell with chimeric antigen receptor) are autologous for humans, which is the problem for use classic toxicity tests. Besides the biomedical product safety becomes questionable, therefore the different preclinical research strategy is developed to solve those problems and produce normal test-systems with therapeutic target. The aim of the study was to evaluate the acute toxicity in immunodeficient BALB/c Nude mice of an antineoplastic drug based on genetically modified T/NK cells that express a chimeric T-cell anti-HER2 receptor. Material and methods. Test and control groups consisted of five males and five females. Animals were injected a single intravenous or intraperitoneal injection of the testing product and the solvent-cryopreserving carrier at the dose 0,2 ml/animal. There were two doses: equal to the human therapeutic 0,5•106 cell/animal dose and ten times over then the therapeutic dose 5•106 cell/animal. During the test the animal’s weight, the food intake and clinically symptoms of the testing product toxicity were registered. On the fifteenth of the study day animals were euthanatized and exposed to a necropsy with the organs’ macroscopic inspection, the weighting and fixating. The detection of the testing biomedical product toxicity was the aim of the histology analysis. Results. A single intravenous or intraperitoneal injection of the biomedical product «anti-HER2-CAR-T/ CAR-NK» at the human therapeutic dose, as well as in 10 times more than the same, is safe for BALB/c Nude mice. The preclinical study has shown the absence of significant toxic effects. Limitations. The research was performed on Balb/c nude line immunodeficient mice, because the tested product contained living foreign cells. Conclusion. This work can be the main basis for the creation of biomedical product preclinical research protocol of biomedical cell products produced from CAR-technology.

Pharmacokinetic Interactions of Phenosanic Acid with Valproic Acid and Carbamazepine in Dogs

Phenosanic acid prevents convulsions, reduces the frequency of epileptic seizures, and improves cognitive, intellectual and mnestic functions in patients with epilepsy. Therefore, phenosanic acid-based medicinal products are promising candidates for inclusion in combination antiepileptic therapy. In order to combine medicinal products rationally and ensure that the therapy is safe, it is useful to study the pharmacokinetic interaction of medicinal products planned for clinical co-administration.The aim of the study was to examine single-dose pharmacokinetic interactions between Dibufelon® 200 mg capsules (PIQ-PHARMA LLC, Russia) and two medicinal products planned for clinical co-application with it, namely, valproic acid and carbamazepine, in sexually mature dogs.Materials and methods: the study included medicinal products of phenosanic acid (Dibufelon® 200 mg capsules by PIQ-PHARMA LLC, Russia), valproic acid (300 mg prolonged-release film-coated tablets), and carbamazepine (200 mg tablets). The medicinal products were administered to beagle dogs (2 groups of 9 males each) as a single oral dose separately and in the following combinations: phenosanic acid with valproic acid and phenosanic acid with carbamazepine. Dose selection involved adjusting maximum human therapeutic doses using interspecies conversion factors. Phenosanic acid was administered at a dose of 24 mg/kg; valproic acid and carbamazepine were administered at a dose of 60 mg/kg. Blood sampling took place at baseline and in 0.5, 0.75, 1, 2, 4, 6, 8, 10, and 24 h after dosing. Plasma concentrations of active substances were determined by HPLC-UV. Pharmacokinetic interactions were evaluated by changes in the main pharmacokinetic parameters (Сmax, Тmax, AUC0-24, MRT, Т1/2).Results: the study demonstrated rapid gastrointestinal absorption and prolonged systemic circulation of phenosanic acid administered separately (Tmax 2–4 h, T1/2 13–28 h) and combined with valproic acid (Tmax 2 h, T1/2 22 h). When administered with carbamazepine, phenosanic acid was eliminated from the systemic blood flow faster (T1/2 7.4 h).Conclusions: co-administration of phenosanic acid and valproic acid medicinal products had no significant effect on their respective pharmacokinetics. Whereas, the combination of phenosanic acid and carbamazepine demonstrated a significant decrease in the Tmax values of phenosanic acid and the MRT values of carbamazepine. The pharmacokinetic changes suggestive of a possible interaction between phenosanic acid and carbamazepine need further clinical investigation.

Developmental safety of nirmatrelvir in zebrafish (Danio rerio) embryos.

Nirmatrelvir, in combination with ritonavir, is one of the first orally available antiviral treatment for coronavirus disease 2019 (COVID-19). Symptomatic pregnant women are at increased risk for severe illness and complications that can affect the developing baby. No malformations or lower embryo-fetal survival have been observed when nirmatrelvir were administered to pregnant rats and rabbits. Safety evaluation of drugs used for treating COVID-19 also in pregnancy is urgent for public health, then in this study we further investigated nirmatrelvir developmental toxicity using zebrafish as in vivo model. Using the standardized Fish Embryo Toxicity (FET) test, we first determined the lethal concentration 50 (LC50), exposing embryos from gastrula stage up to 120 hr post fertilization (hpf) and daily recording lethality. Then, we exposed embryos to five doses comprising the human therapeutic one and up to the LC50 (25 μM). Morphology was evaluated at 72 and 120 hpf. Nirmatrelvir did not affect survival rate and did not induce morphological defects up to the human therapeutic dose. Exposure at higher doses (2.4× and 3× the human Cmax ) however resulted in decreased hatching rate, reduced growth, slower heartbeat with pericardial edema, reduction of eye dimension, absence of the swim bladder and disruption of the anterior-posterior axis, with lack of tail detachment, spinal curvature and straight and smaller head. Our findings in zebrafish embryos add further information about developmental nirmatrelvir safety. Further studies are needed for pharmacological safety assessment of nirmatrelvir exposure during pregnancy.

Influence of time-dependent sampling on fish plasma levels of select pharmaceuticals and per- and polyfluoroalkyl substances (PFASs)

Determining pharmaceutical levels in fish plasma represents an increasingly valuable approach for environmental assessments of pharmaceuticals. These fish plasma observations are compared to human therapeutic plasma doses because of the high evolutionary conservation of many drug targets among vertebrates. In the present study, we initially identified highly variable information regarding plasma sampling practices in the literature and then tested the hypothesis that fish plasma levels of selected pharmaceuticals and per- and polyfluoroalkyl substances (PFASs) would not change with time to process samples from the field. After common carp were placed in a wastewater-fed pond for one month, we immediately sampled fish plasma nonlethally in the field or after transferring fish to clean water and held them under these conditions for either 3 or 20 h. We then quantitated pharmaceuticals in water, and pharmaceuticals and PFASs in plasma by LC-MSMS. Whereas plasma levels of most pharmaceuticals decreased even after 3 h that fish spent in clean water, plasma concentrations of the PFASs examined here remained stable over 20 h. Collectively, our examination of these time-dependent sampling approaches and associated findings highlight the importance of appropriate and consistent sampling for bioaccumulation studies, biomonitoring activities, and aquaculture product safety evaluations.

Colchicine overdose impairs the capacity of Kupffer cells to clear foreign particles and endotoxins

Colchicine is an anti-inflammatory drug with a narrow therapeutic index. Its binding to tubulin prevents microtubule polymerization; however, little is known about how depolymerization of microtubules interferes with the phagocytosis function of Kupffer cells (KC). Here, we applied functional intravital imaging techniques to investigate the influence of microtubule disruption by colchicine on KC morphology, as well as its capacity to clear foreign particles and bacterial lipopolysaccharide (LPS) in anesthetized mice. Intravital imaging of KC in healthy mice showed the typical elongated morphology, localization at the luminal side of the sinusoidal endothelial cells, and moving cell protrusions. In contrast, at colchicine doses of 1 mg/kg and higher (intraperitoneal), KC appeared roundish with strongly reduced protrusions and motility. To study the functional consequences of these alterations, we analyzed the capacity of KC to phagocytose fluorescent nanospheres (100 nm-size) and LPS. After tail vein injection, the nanospheres formed aggregates of up to ~ 5 µm moving along the sinusoidal bloodstream. In controls, the nanosphere aggregates were rapidly captured by the Kupffer cell protrusions, followed by an internalization process that lasted up to 10 min. Similar capture events and internalization processes were observed after the administration of fluorescently labeled LPS. In contrast, capture and internalization of both nanospheres and LPS by KC were strongly reduced in colchicine-treated mice. Reduced phagocytosis of LPS was accompanied by aggravated production of inflammatory cytokines. Since 0.4 mg/kg colchicine in mice has been reported to be bio-equivalent to human therapeutic doses, the here-observed adverse effects on KC occurred at doses only slightly above those used clinically, and may be critical for patients with endotoxemia due to a leaky gut–blood barrier.

Experimental Study of the Efficacy and Safety of a New PEG-Based Laxative

Bowel-cleansing PEG-based agents, including Moviprep®, are commonly used to prepare the large intestine for diagnostic examinations. PLNV-next is a newly developed fixed combination medicinal product with a composition similar to that of Moviprep®.The aim of the study was to estimate the pharmacological efficacy and toxicity of PLNV-next.Materials and methods: The study evaluated pharmacological efficacy of four formulations of PLNV-next in comparison with Moviprep® after a single administration in a therapeutic dose to outbred rats. The evaluation was carried out based on the laxative effect of the medicinal products. The authors recorded diarrhoea onset latency and the number of defecation boluses and diarrhoea spots produced during the 6-hour observation period. Toxicity of PLNV-next was studied in the formulation containing maximum amounts of the ingredients according to the patent. In the single-dose toxicity study, PLNV-next was administered intragastrically to rats at doses of 4.2 g/kg (maximum human therapeutic dose, MHTD), 21 g/kg (5 MHTD), and 42 g/kg (10 MHTD) and to ferrets at doses of 4.2 g/kg (MHTD) and 21 g/kg (5 MHTD). In the repeated-dose toxicity study, PLNV-next was administered for 14 days at 4.2 g/kg (rats and ferrets), 21 g/kg (5 MHTD, rats), and 12.6 g/kg (3 MHTD, ferrets). Additionally, the repeated-dose toxicity study evaluated safety pharmacology parameters for the cardio-vascular, respiratory and central nervous systems.Results: All PLNV-next formulations tested exerted a laxative effect equivalent to that of Moviprep®. No clinical signs of toxicity were observed in rats, with the exception of the laxative effect. Ferrets demonstrated decreased behavioral activity and diarrhoea. Nausea or emesis were noted in 75–90% of the ferrets receiving the doses exceeding the MHTD. A single administration of PLNV-next affected blood sodium concentrations: a slight increase was noted in the 5 MHTD and 10 MHTD groups of rats and in the 5 MHTD group of ferrets. The repeated-dose toxicity study in rats revealed a slight increase in sodium levels with both test doses. After a single administration of 5 MHTD to ferrets, the authors observed a decrease in potassium levels. All the changes were mild and within physiological ranges. PLNV-next toxic effects observed in the rat and ferret studies were similar to those reported in rat and dog toxicity studies of Moviprep®. Conclusion: PLNV-next exerts a marked laxative effect and has a favourable safety profile.

Next Generation Risk Assessment of the Anti-Androgen Flutamide Including the Contribution of Its Active Metabolite Hydroxyflutamide.

In next generation risk assessment (NGRA), non-animal approaches are used to quantify the chemical concentrations required to trigger bioactivity responses, in order to assure safe levels of human exposure. A limitation of many in vitro bioactivity assays, which are used in an NGRA context as new approach methodologies (NAMs), is that toxicokinetics, including biotransformation, are not adequately captured. The present study aimed to include, as a proof of principle, the bioactivity of the metabolite hydroxyflutamide (HF) in an NGRA approach to evaluate the safety of the anti-androgen flutamide (FLU), using the AR-CALUX assay to derive the NAM point of departure (PoD). The NGRA approach applied also included PBK modelling-facilitated quantitative in vitro to in vivo extrapolation (QIVIVE). The PBK model describing FLU and HF kinetics in humans was developed using GastroPlus™ and validated against human pharmacokinetic data. PBK model-facilitated QIVIVE was performed to translate the in vitro AR-CALUX derived concentration-response data to a corresponding in vivo dose-response curve for the anti-androgenicity of FLU, excluding and including the activity of HF (-HF and +HF, respectively). The in vivo benchmark dose 5% lower confidence limits (BMDL05) derived from the predicted in vivo dose-response curves for FLU, revealed a 440-fold lower BMDL05 when taking the bioactivity of HF into account. Subsequent comparison of the predicted BMDL05 values to the human therapeutic doses and historical animal derived PoDs, revealed that PBK modelling-facilitated QIVIVE that includes the bioactivity of the active metabolite is protective and provides a more appropriate PoD to assure human safety via NGRA, whereas excluding this would potentially result in an underestimation of the risk of FLU exposure in humans.

Mitigated Oxidative Stress and Cognitive Impairments in Transient Global Ischemia using Niosomal Selegiline-NBP delivery.

Stroke is the most common reason for adult disabilities and the second ground for death worldwide. Our previous study revealed that selegiline serves as an alternative candidate in transient hypoxia-ischemia. However, aggressive and restless behavior was observed in stroke-induced rats receiving 4 mg/kg selegiline. In comparison, 1 mg/kg selegiline could induce negligible therapeutic effects on mitochondrial dysfunction and histopathological changes. Therefore, we designed oral noisome-based selegiline attached to 4-(4-nitrobenzyl) pyridine to improve transient global ischemia by attenuating cognitive impairments, oxidative stress, and histopathological injury. The investigation was performed in transient hypoxia-ischemia-induced rats by oral administration of nanoformulation containing selegiline (0.25-1 mg/kg) for 4 weeks (3 times a week). Novel object recognition (NOR) was considered to evaluate their cognitive dysfunction. Oxidative stress parameters and brain histopathological assessments were determined following the scarification of rats. Outstandingly, our data demonstrated slower selegiline release from niosomes relative to free drug, which was also in a controlled manner. Our data confirmed significant improvement in cognitive behavior in the NOR test, an increase in glutathione level and total antioxidant power, a decline in MDA and protein carbonyl level, as well as a decreased number of dead cells in histopathological assessment after being exposed to (0.5-1 mg/kg) selegiline-NBP nanoformulation. These data manifested that the selegiline-NBP nanoformulation (0.5-1 mg/kg) could significantly reduce oxidative damage, cognitive dysfunction, and histopathological damage compared to transient hypoxia-ischemia rats, which is 20 times lower than the therapeutic dose in humans. Therefore, the proposed nanoformulation would be capable as an alternative candidate without side effects in stroke.

Preclinical safety evaluation of levonadifloxacin, a novel anti-methicillin-resistant Staphyloccocus aureus benzoquinolizine fluoroquinolone by intravenous and oral administration.

Fluoroquinolone (FQ) antibacterials have drawn heightened attention from various international regulatory agencies due to their class-specific side effects. Levonadifloxacin is a novel broad spectrum benzoquinolizine FQ active against methicillin-resistant Staphyloccocus aureus (MRSA). Owing to FQ-associated safety concerns, extensive preclinical safety pharmacology (central nervous system and cardiac safety) and toxicology studies (subacute repeat-dose toxicity, genotoxicity, phototoxicity and chondrotoxicity) of levonadifloxacin were performed at relatively high doses. Intravenous (IV) and oral studies were conducted using WCK 771 (l-arginine salt of levonadifloxacin) and WCK 2349 (l-alanine ester prodrug of levonadifloxacin), respectively. Safety pharmacology studies following single dose revealed no adverse effects on central nervous system (including seizure) in mice and cardiovascular system (hERG and monkey telemetry). In repeat-dose toxicity studies, except for IV bolus dosing related effects in rat (hyperactivity, mild convulsion, polypnoea and injection site irritation) and dog (emesis and salivation), no other adverse findings limiting the dosing duration were observed. No major biochemical, haematological, gross or histopathological changes suggestive of damage to vital organs were observed in either WCK 771- or WCK 2349-treated groups. WCK 771 and WCK 2349 were found to be nongenotoxic; however, they showed weak phototoxicity that was comparable with levofloxacin. WCK 771 showed chondrotoxicity in the Beagle dog pups on repeat-dose administration; however, the severity level was lower than ofloxacin. Overall, preclinical safety studies helped establish wider safety margin for WCK 771 and WCK 2349 that supports administration of higher therapeutic doses in humans by both IV and oral routes, thereby enabling safe anti-MRSA treatment.

Targeting Thyrointegrin αvβ3 Using Fluorobenzyl Polyethylene Glycol Conjugated Tetraiodothyroacetic Acid (NP751) in Acute Myeloid Leukemia.

BackgroundAcute myeloid leukemia (AML) is associated with poor long-term survival, even with newer therapeutic agents. Here, we show the results of our preclinical study, in which we evaluated the efficacy of a new thyrointegrin αvβ3 antagonist, named fluorobenzyl polyethylene glycol conjugated tetraiodothyroacetic acid (fb-PMT).Methods and Resultsfb-PMT (NP751) is a potent αvβ3 antagonist of molecular weight of 2,478.9 Da. it represents a conjugate of tetraiodothyroacetic acid (tetrac) and monodisperse polyethylene glycol (PEG36), with a 4-fluorobenzyl group capping the other end of the PEG. fb-PMT effectively suppresses the malignant growth of human acute myeloid leukemia (AML) after successful engraftment in transgenic NSG-S xenograft mouse models of either established human AML cell line or primary AML cells. Daily treatment with fb-PMT (1–10 mg/kg body weight) subcutaneously (s.c.) for 3–4 weeks was associated with marked regression of leukemogenesis and extended survival in both models. The efficiency of the fb-PMT therapy was verified using in vivo imaging system (IVIS) imaging, flow cytometry, and histopathological examination to monitor the engraftment of leukemic cells in the bone marrow and other organs. fb-PMT therapy for 3–4 weeks at 3 and 10 mg/kg daily doses exhibited significant reduction (p < 0.0001) of leukemic cell burden of 74% and >95%, respectively. All fb-PMT-treated mice in the 10 mg/kg treatment arm successfully maintained remission after discontinuing the daily treatment. Comprehensive fb-PMT safety assessments demonstrated excellent safety and tolerability at multiple folds above the anticipated human therapeutic doses. Lastly, our genome-wide microarray screens demonstrated that fb-PMT works through the molecular interference mechanism with multiple signaling pathways contributing to growth and survival of leukemic cells.ConclusionOur preclinical findings of the potent anticancer activities of fb-PMT and its favorable safety profiles warrant its clinical investigation for the effective and safe management of AML.

Effect of ofatumumab on pregnancy, parturition, and lactation in cynomolgus monkeys

Knowledge of the impacts of the anti-CD20 monoclonal antibody ofatumumab on the developing immune system is limited. This study examined the effects of intravenous ofatumumab on pregnancy, parturition, and lactation, and on pre- and postnatal survival and development in cynomolgus monkeys, an established model for developmental toxicity assessment. Pregnant cynomolgus monkeys (n = 42) were randomized to receive vehicle only (control group; n = 14), low-dose ofatumumab (n = 14), or high-dose ofatumumab (n = 14). Survival, clinical outcomes, and clinical pathology investigations were evaluated regularly until lactation day (maternal animals) and postnatal day 180±1 (infants). Anatomic pathology was investigated in euthanized infants and unscheduled terminations of maternal animals and infants. Ofatumumab treatment was not associated with maternal toxicity or embryotoxicity and had no effect on the growth and development of offspring. As expected, B-cell depletion occurred in maternal animals and their offspring, with a reduced humoral immune response in infants of mothers on high-dose ofatumumab. Both effects were reversible. In the high-dose group, perinatal deaths of 3 infants were attributed to infections, potentially secondary to pharmacologically induced immunosuppression. The no-observed adverse-effect level for initial/maintenance ofatumumab doses was 100/20 mg, and 10/3 mg/kg for pharmacological effects in infant animals, which are associated with exposures significantly higher than those following therapeutic doses in humans. In this study with cynomolgus monkeys, ofatumumab treatment was not associated with maternal toxicity or embryotoxicity and had no effect on the growth and development of offspring.

Preclinical Studies into Specific Toxicity of a Candidate Drug Based on Complement C3 neodeterminant Recombinant Humanized Antibody for Treating Traumatic Brain Injuries

This study aims to assess the specific toxicity (allergenicity, immunotoxicity and reproduction toxicity) of a dosage form of complement C3 neodeterminant recombinant humanized antibody. The reactions of general anaphylaxis, active cutaneous anaphylaxis and delayed-type reaction demonstrated no drug-related signs of experimental animal sensitization and immediate or delayed hypersensitivity in the treated animals. It was found that, in doses exceeding significantly the expected human therapeutic dose, the drug has no effect on humoral and cell-mediated immune responses. In addition, the drug does not suppress the phagocytic cell activity thereby indicating the absence of immunotoxic effect. Moreover, the drug has no adverse effects on male and female reproduction, progeny embryonal development, as well as prenatal and postnatal progeny development. The obtained data can be used in future clinical studies of the drug safety.