Safety assessment of a novel, dietary pyrroloquinoline quinone disodium salt (mnemoPQQ®).

Pyrroloquinoline quinone (PQQ), a potent coenzyme antioxidant naturally occurring in foods, has been demonstrated to protect brain cells by enhancing the expression of nerve growth factors (NGF) and NGF receptors, and suppressing the fibril formation and aggression of amyloid ß. We developed mnemoPQQ®, a novel PQQ disodium salt and assessed its safety in GLP compliant toxicity studies. Acute toxicity studies of mnemoPQQ® in Wistar rats revealed that its LD50 was 1825- and 1410 mg/kg body weight (bw) in male and female rats, respectively, whereas its acute dermal LD50 was >2000 mg/kg bw. mnemoPQQ® was found to be nonirritant to the skin of rabbit in an acute dermal irritation/corrosion study, and classified mnemoPQQ® as a nonirritant to the eye of rabbit in an acute eye irritation/corrosion study. Ames bacterial reverse mutation assay and in vitro Mammalian cell gene mutation test exhibited its non-mutagenic potential. In mammalian in vivo erythrocyte micronucleus test, mnemoPQQ® was classified as non-clastogenic and non-mutagenic. A 90-day sub-chronic toxicity study, conducted at and up to the highest daily dose of 600 mg/kg body weight, revealed no evidence of systemic toxicity. All rats survived the treatment without any significant abnormal clinical signs and alterations in hematology, clinical chemistry, neurological evaluation, thyroid functions, reproductive hormone levels, sperm evaluations, vaginal cytology, endocrine functions, organ weight and gross and microscopic pathology findings. No observed adverse effect level (NOAEL) of mnemoPQQ® was found to be greater than 600 mg/kg body weight. These studies affirm that mnemoPQQ® has broad spectrum safety for human consumption.

Palmitoylethanolamide: Prenatal Developmental Toxicity Study in Rats.

Palmitoylethanolamide (PEA) is an endogenous ethanolamine playing a protective and homeodynamic role in animals and plants. Prenatal developmental toxicity of PEA was tested following oral administration to pregnant female Wistar rats, from days 0 to 19 of gestation, at dosage of 250, 500, or 1,000 mg/kg body weight, according to Organisation for Economic Co-operation and Development Test Guideline No. 414. On gestation day 20, cesarean sections were performed on the dams, followed by examination of their ovaries and uterine contents. The fetuses were further examined for external, visceral, and skeletal abnormalities. Palmitoylethanolamide did not cause any alterations at any of the given dosages in the measured maternal parameters of systemic toxicity (body weight, food consumption, survival, thyroid functions, organ weight, histopathology), reproductive toxicity (preimplantation and postimplantation losses, uterus weight, number of live/dead implants and early/late resorptions, litter size and weights, number of fetuses, their sex ratio), and fetal external, visceral, or skeletal observations. Any alterations that were recorded were "normal variations" or "minor anomalies," which were unrelated to treatment with PEA. Under the condition of this prenatal study, the no-observed-adverse-effect level of PEA for maternal toxicity, embryotoxicity, fetotoxicity, and teratogenicity in rats was found to be >1,000 mg/kg body weight/d. It indicates that PEA is well tolerated by and is safe to pregnant rats even at a high dose of 1,000 mg/kg body weight/d, equivalent to a human dose of greater than 9.7 g/d. This prenatal developmental toxicity study contributes greatly in building a robust safety profile for PEA.

Safety assessment of a hydroethanolic extract of Caralluma fimbriata.

This toxicological assessment evaluated the safety of a hydroethanolic extract prepared from Caralluma fimbriata (CFE), a dietary supplement marketed worldwide as an appetite suppressant. Studies included 2 in vitro genotoxicity assays, a repeated dose oral toxicity study, and a developmental study in rats. No evidence of in vitro mutagenicity or clastogenicity surfaced in the in vitro studies at concentrations up to 5000 µg of extract/plate (Ames test) or 5000 µg of extract/mL (chromosomal aberration test). No deaths or treatment-related toxicity were seen in the 6-month chronic oral toxicity study in Sprague-Dawley rats conducted at 3 doses (100, 300, and 1000 mg/kg body weight (bw)/d). The no observed effect level for CFE in this study was considered to be 1000 mg/kg bw/d. A prenatal developmental toxicity study conducted at 3 doses (250, 500, and 1000 mg/kg bw/d) in female Sprague-Dawley rats resulted in no treatment-related external, visceral, or skeletal fetal abnormalities, and no treatment-related maternal or pregnancy alterations were seen at and up to the maximum dose tested. CFE was not associated with any toxicity or adverse events.

A Comprehensive Molecular and Clinical Investigation of Approved Anti-HCV Drugs Repurposing against SARS-CoV-2 Infection: A Glaring Gap between Benchside and Bedside Medicine.

The limited availability of effective treatment against SARS-CoV-2 infection is a major challenge in managing COVID-19. This scenario has augmented the need for repurposing anti-virals for COVID-19 mitigation. In this report, the anti-SARS-CoV-2 potential of anti-HCV drugs such as daclatasvir (DCV) or ledipasvir (LDP) in combination with sofosbuvir (SOF) was evaluated. The binding mode and higher affinity of these molecules with RNA-dependent-RNA-polymerase of SARS-CoV-2 were apparent by computational analysis. In vitro anti-SARS-CoV-2 activity depicted that SOF/DCV and SOF/LDP combination has IC50 of 1.8 and 2.0 µM, respectively, comparable to remdesivir, an approved drug for COVID-19. Furthermore, the clinical trial was conducted in 183 mild COVID-19 patients for 14 days to check the efficacy and safety of SOF/DCV and SOF/LDP compared to standard of care (SOC) in a parallel-group, hybrid, individually randomized, controlled clinical study. The primary outcomes of the study suggested no significant difference in negativity after 3, 7 and 14 days in both treatments. None of the patients displayed any worsening in the disease severity, and no mortality was observed in the study. Although, the post hoc exploratory analysis indicated significant normalization of the pulse rate showed in SOF/DCV and SOF/LDP treatment vs. SOC. The current study highlights the limitations of bench side models in predicting the clinical efficacy of drugs that are planned for repurposing.

Silk Fibroin Microparticle Scaffold for Use in Bone Void Filling: Safety and Efficacy Studies.

Silk fibroin (SF) is a natural biocompatible protein polymer extracted from cocoons of silkworm Bombyx mori. SF can be processed into a variety of different forms and shapes that can be used as scaffolds to support bone regeneration. Three-dimensional (3D) SF scaffolds have shown promise in bone-void-filling applications. In in vitro studies, it has been demonstrated that a microparticle-based SF (M-RSF) scaffold promotes the differentiation of stem cells into an osteoblastic lineage. The expression of differentiation markers was also significantly higher for M-RSF scaffolds as compared to other SF scaffolds and commercial ceramic scaffolds. In this work, we have evaluated the in vitro and in vivo biocompatibility of M-RSF scaffolds as per the ISO 10993 guidelines in a Good Laboratory Practice (GLP)-certified facility. The cytotoxicity, immunogenicity, genotoxicity, systemic toxicity, and implantation studies confirmed that the M-RSF scaffold is biocompatible. Further, the performance of the M-RSF scaffold to support bone formation was evaluated in in vivo bone implantation studies in a rabbit model. Calcium sulfate (CaSO4) scaffolds were chosen as reference material for this study as they are one of the preferred materials for bone-void-filling applications. M-RSF scaffold implantation sites showed a higher number of osteoblast and osteoclast cells as compared to CaSO4 implantation sites indicating active bone remodeling. The number density of osteocytes was double for M-RSF scaffold implantation sites, and these M-RSF scaffold implantation sites were characterized by enhanced collagen deposition, pointing toward a finer quality of the new bone formed. Moreover, the M-RSF scaffold implantation sites had a negligible incidence of secondary fractures as compared to the CaSO4 implantation sites (∼50% sites with secondary fracture), implying a reduction in postsurgical complications. Thus, the study demonstrates that the M-RSF scaffold is nontoxic for bone-void-filling applications and facilitates superior healing of fracture defects as compared to commercial calcium-based bone void fillers.

Safety assessment of McB-E60 (extract of a Momordica sp.): Subchronic toxicity study in rats.

Momordica charantia plant is consumed as a foodstuff in some south Asian curries while its extract preparations have been traditionally used for lowering blood glucose levels in patients with diabetes mellitus. Nutritional Health Institute Laboratories (NHIL), LLC, Florida informed that it patented a new plant McB, as an interhybrid of three plants of Momordica genus. The objective of the present study was to investigate potential adverse effects, if any, of McB-E60 (extract of a Momordica sp.) in rats following subchronic administration. Sprague-Dawley rats (10/sex/group) were administered via oral gavage 0 (control), 250, 500 and 1000 mg/kg body weight (bw)/day of McB-E60 for 90 days. Additional 28-day recovery groups were maintained at control and high dose levels. No mortality or significant and adverse changes in clinical signs, neurological signs, body weight gain or feed intake were noted. No toxicologically significant changes in hematology, clinical chemistry, urinalysis and organ weights were noted. Gross and microscopic pathology examinations did not reveal treatment-related abnormalities. Any changes noted were incidental and within historical control ranges. Based on the results of this study, the No-Observed-Effect Level (NOEL) for McB-E60 (extract of a Momordica sp.) was determined as greater than 1000 mg/kg bw/day, the highest dose tested.