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Over the last two years, global regulatory authorities have raised safety concerns on nitrosamine contamination in several drug classes, including angiotensin II receptor antagonists, histamine-2 receptor antagonists, antimicrobial agents, and antidiabetic drugs. To avoid carcinogenic and mutagenic effects in patients relying on these medications, authorities have established specific guidelines in risk assessment scenarios and proposed control limits for nitrosamine impurities in pharmaceuticals. In this review, nitrosation pathways and possible root causes of nitrosamine formation in pharmaceuticals are discussed. The control limits of nitrosamine impurities in pharmaceuticals proposed by national regulatory authorities are presented. Additionally, a practical and science-based strategy for implementing the well-established control limits is notably reviewed in terms of an alternative approach for drug product N-nitrosamines without published AI information from animal carcinogenicity testing. Finally, a novel risk evaluation strategy for predicting and investigating the possible nitrosation of amine precursors and amine pharmaceuticals as powerful prevention of nitrosamine contamination is addressed.

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Combination drugs have been used for several diseases for many years since they produce better therapeutic effects. However, it is still a challenge to discover candidates to form a combination drug. This study aimed to investigate whether using a comprehensive in silico approach to identify novel combination drugs from a Chinese herbal formula is an appropriate and creative strategy. We, therefore, used Toujie Quwen Granules for the main protease (Mpro) of SARS-CoV-2 as an example. We first used molecular docking to identify molecular components of the formula which may inhibit Mpro. Baicalein (HQA004) is the most favorable inhibitory ligand. We also identified a ligand from the other component, cubebin (CHA008), which may act to support the proposed HQA004 inhibitor. Molecular dynamics simulations were then performed to further elucidate the possible mechanism of inhibition by HQA004 and synergistic bioactivity conferred by CHA008. HQA004 bound strongly at the active site and that CHA008 enhanced the contacts between HQA004 and Mpro. However, CHA008 also dynamically interacted at multiple sites, and continued to enhance the stability of HQA004 despite diffusion to a distant site. We proposed that HQA004 acted as a possible inhibitor, and CHA008 served to enhance its effects via allosteric effects at two sites. Additionally, our novel wavelet analysis showed that as a result of CHA008 binding, the dynamics and structure of Mpro were observed to have more subtle changes, demonstrating that the inter-residue contacts within Mpro were disrupted by the synergistic ligand. This work highlighted the molecular mechanism of synergistic effects between different herbs as a result of allosteric crosstalk between two ligands at a protein target, as well as revealed that using the multi-ligand molecular docking, simulation, free energy calculations and wavelet analysis to discover novel combination drugs from a Chinese herbal remedy is an innovative pathway.

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Damnacanthal is an anthraquinone, extracted, and purified from the root of Morinda citrifolia in Thailand. This study aimed to measure acute oral toxicity and to investigate the anticancer activity of damnacanthal in colorectal tumorigenesis. We found that the growth of human colorectal cancer cells was inhibited by damnacanthal in a dose- and a time-dependent manner. The growth inhibitory effect of damnacanthal was better than that of 5-FU used as a positive control in colorectal cancer cells, along with the downregulation of cell cycle protein cyclin D1. Similarly, an oral treatment of damnacanthal effectively inhibited the growth of colorectal tumor xenografts in nude mice, which was approximately 2-3-fold higher as compared to 5-FU by tumor size as well as expression of bioluminescence. Furthermore, the study of acute oral toxicity in mice exhibited a relatively low toxicity of damnacanthal with a LD50 cut-off value of 2500 mg/kg according to OECD Guideline 423. These results reveal the potential therapeutic activity of a natural damnacanthal compound as an anti-colorectal cancer drug.

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Objectives: To investigate the effect of kolaviron against haematological abnormalities and hepato-renal damage in Naja n. nigricollis (NNN) venom-treated rats. Methods: Twenty-four male rats were grouped into four (n = 6). A single intravenous dose of NNN venom (≈½LD50) was given to group B-D (excluding A). All the groups were immediately treated intraperitoneally as follows: A (Normal control) and B (Envenom) received 0.40 mL/kg of 0.1% Tween 80, while C and D (test groups), received 200 and 400 mg/kg of kolaviron respectively. After 6 h, they were anaesthetized, and sacrificed. Results: NNN-venom LD50 was estimated at 1.14 mg/kg. Injected half LD50, after 6 h, caused significant (p < 0.05) decreases in RBC, HGB and PCV, with increases in WBC and NEUT. Significantly (p < 0.05) increased AST, ALT, GGT, TB, CRE, URE, UA and K with concomitant decreases in Na and HCO3. Oxidant/antioxidant markers (MDA, CAT and SOD) were significantly (p < 0.05) increased in liver and kidney homogenates. Histological analysis confirmed liver and kidney injuries. All these alterations were alleviated dose-dependently, when cotreated with kolaviron at 200 and 400 mg/kg. Conclusions: Our study suggests that kolaviron could alleviates haematological abnormalities and hepato-renal damage in NNN venom-treated rats by depleting ROS and/or boasting the antioxidant system.

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A novel functional drink with nutraceutical properties was formulated from the aqueous extracts of Ilex guayusa, and Vernonanthura patens leaves, and cocoa husks. This juice contains various bioactive compounds, such as phenolic compounds and methylxanthines, with antioxidant and stimulant properties of pharmacological interest. However, it is known whether herbal extracts' interaction may have adverse toxic effects on human health. To evaluate this functional drink's innocuity, we estimated the acute oral toxicity (AOT) in experimental mice. This paper presents the AOT evaluation of two formulations of a functional drink (pre-formulation and microencapsulation) at a single dose of 2000 mg/kg of body weight (b.w.). No signs of adverse toxicity and mortality were observed after a single oral dose of 2000 mg/kg b.w. Likewise, no significant body and organ weight changes, food and water consumption behavior, and no histopathological changes were observed in the main organs evaluated. In conclusion, this functional drink can be categorized as low toxicity " according to the Globally Harmonized Classification System (GHS), making it a potential beverage with high nutritional and pharmacological value.

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Diospyros mespiliformis, commonly called Jackal berry or African ebony, belongs to the plant family, Ebenaceae. The roots, barks and leaves have been used traditionally to treat wide varieties of conditions, however, there is limited information and literature reports concerning the toxicity and safety of this plant. The present study was conducted to evaluate the acute and sub-chronic toxicity of the crude methanolic extract of Diospyros mespiliformis and its fraction in Wistar rats. Diospyros mespiliformis was extracted by methanol 96 %. The crude methanolic extract was then fractionated into low, average and high polar compounds using hexane, ethyl acetate and butanol respectively. For the acute toxicity study, the revised limit Dose Test of "Up and Down" procedure according to the OECD guideline was used to determine the median lethal dose (LD50) of the crude methanolic leaf and bark extracts using a single fixed dose (5 g/kg) of the extracts administered by oral-gavage sequentially to 5 female Wistar rats. The rats were observed for instant death and toxicity signs for 24 h and then daily for 14 days. In the sub-chronic toxicity study, the bark and leaf ethyl acetate fractions (extract) was administered orally at doses of 250, 500 and 750 mg/kg bw /day respectively for 28 days to healthy Wistar rats. At the end of the experimental period, body weight, certain haematological, serum biochemical and histopathological parameters were evaluated. Results showed that acute oral administration of crude methanolic extract of Diospyros mespiliformis (5 g/kg bw) produced neither mortality nor visible changes in behavior or any other physiological activities and indicated that the LD50 of crude methanolic leaf and bark extract was greater than 5 g/kg bw in Wistar Rats. In the 28-days repeated dose oral toxicity study, no significant toxic effects was detected in any of the parameters evaluated. In conclusion, the crude methanolic extract was found safe in the acute toxicity study and the ethyl acetate fraction of Diospyros mespiliformis in the sub chronic study in rats could be safe for therapeutic purposes over a period not exceeding 28 days.

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Cr (chromium, with common valence states of III and VI) is one of the common broiler feed additives. Liver injury and metabolic disorders could be caused by Cr(VI) (hexavalent chromium) poisoning in broilers. Oxidative damage and metabolic disorders of organisms caused by heavy metals could be antagonized by nano-Se (nano-selenium). Nano-Se was chosen to study the antagonism of Cr(VI) poisoning in broilers. AMPK (Adenosine 5,-monophosphate-activated protein kinase) is known as a "cell energy regulator" and plays a key regulatory role in carbohydrate and lipid metabolism. AMPK pathway and ACACA/CPT1A two genes were selected to study the prevention and treatment of nano-Se on Cr(VI) poisoning in broilers and its molecular mechanism. For this purpose, 180 1-day-old AA (Arbor Acres) broilers were selected and randomly divided into 6 groups (n = 30) for further testing. After feeding as planned for 35 days, the livers of such broilers were taken for further examination including histopathological examination, differential gene expression analysis, and further validation on both mRNA and protein levels using related techniques like RT-qPCR, western blot, and immunohistochemistry (IHC). The histopathological examination suggested that the liver cells of the Cr(VI) poisoning group were more severely injured than the nano-Se addition group. RT-qPCR results showed that the relative expression of ACACA gene in the Cr(VI) poisoning group was significantly increased (P < 0.05), while the CPT1A gene's expression was significantly decreased (P < 0.01). Those results were reversed in the nano-Se addition group. Western blot results were consistent with RT-qPCR and both suggested antagonism of nano-Se on Cr(VI). Through morphological and histopathological observation, as well as the measurement of the mRNA and protein expression levels of ACACA and CPT1A genes in AMPK pathway, it was confirmed that nano-Se has certain preventive and protective effects on Cr(VI) poisoning in broiler chickens. Furthermore, the adverse effects of Cr(VI) on carbohydrate and lipid metabolism in broilers can be antagonized by nano-Se through AMPK pathway. A new method and experimental basis were provided to the future study of Cr(VI) poisoning in broilers.

Asunto(s)

Selenio , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Pollos , Cromo/metabolismo , Cromo/toxicidad , Metabolismo de los Lípidos , Hígado/metabolismo , Selenio/metabolismo

RESUMEN

The data present in this article is related to evaluation of standardized methanolic extract of Vernonia elaeagnifolia aerial parts [MEVE], a species of Asteraceae family for antiulcer potential. Antiulcer activity of MEVE (200 and 400 mg/kg, b.w., p.o.) was evaluated with ethanol and aspirin induced ulcer models and pylorus ligation induced gastric ulcer model. The antioxidant potential of MEVE was evaluated with nitric oxide radicals, hydroxyl radical and H2O2 radical scavenging assay against standard ascorbic acid to correlate antioxidant and antiulcerogenic action. MEVE significantly protects the gastric mucosa against the ethanol and aspirin induced ulcer and pylorus ligation induced ulcer challenge. MEVE had shown significant [normal control: p < 0.0001, disease control: p < 0.0001, standard: p < 0.0001] decrease in the ulcer index produced by all three models in rats as compared to the standard drug omeprazole [20 mg/kg, b.w., p.o.]. The present data suggest that aerial parts of Vernonia elaeagnifolia possess significant antiulcer activity, which may attributed to its antioxidant mechanism of action.

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The apoptosis activity and clinical state in vitamin and mineral supplemented male Wistar rats was evaluated after carbon tetrachloride exposure (CCL4). The animals were divided equally into 6 groups (3 control groups and 3 exposure groups) with the control groups (C-75, C-30, C-19) receiving AIN-93, a specific diet for rodents, consisting of a 75%, 30% and 19% ratio of vitamins (B1, B2, B3, B6) and minerals (Fe3+ and Mg2+) and exposure groups (E-75, E-30, E-19) receiving the same diet paradigm as with the control groups but with the additional CCL4 administered once a week as an olive oil solution (control groups received the same ratio of olive oil without CCL4) for a duration of 64 days. The systemic condition of the male Wistar rats was evaluated based on morphological parameters and hematological and biochemical analysis, whereas the apoptosis activity in the liver was evaluated via comet assay techniques. The apoptosis activity in the liver of control and exposure groups increased compared to the decrease in the essential substance provisions with the E-75 group reaching 129% (p < 0.05) higher levels compared to the C-75 group, and 98% (p < 0.05) and 23% (p > 0.05) higher in the E-30 and E-19 groups compared to the C-30 and C-19 groups, respectively. From the apoptosis results and clinical state evaluation, it is clearly demonstrated that the effectiveness of using apoptosis activity as a biomarker after CCL4 exposure and the vitamin and mineral absorption capability in male Wistar rats can be applied as an evaluating method for toxicological research.

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Advancements in in silico techniques of lead molecule selection have resulted in the failure of around 70% of new chemical entities (NCEs). Some of these molecules are getting rejected at final developmental stage resulting in wastage of money and resources. Unfavourable physicochemical properties affect ADME profile of any efficacious and potent molecule, which may ultimately lead to killing of NCE at final stage. Numerous techniques are being explored including nanocrystals for solubility enhancement purposes. Nanocrystals are the most successful and the ones which had a shorter gap between invention and subsequent commercialization of the first marketed product. Several nanocrystal-based products are commercially available and there is a paradigm shift in using approach from simply being solubility enhancement technique to more novel and specific applications. Some other aspects in relation to parenteral nanosuspensions are concentrations of surfactant to be used, scalability and in vivo fate. At present, there exists a wide gap due to poor understanding of these critical factors, which we have tried to address in this review. This review will focus on parenteral nanosuspensions, covering varied aspects especially stabilizers used, GRAS (Generally Recognized as Safe) status of stabilizers, scalability challenges, issues of physical and chemical stability, solidification techniques to combat stability problems and in vivo fate.

RESUMEN

Desiccation is an important limiting factor in the intertidal zone. Generally decreasing seaward, desiccation stress can also be alleviated in wet microhabitats. Juvenile snails are generally more susceptible to desiccation than adults, and, for some species, juveniles must therefore hide in microhabitats to survive emersion. The transition from hiding in safe microhabitats to being able to survive fully exposed for the duration of low tide is not well documented. In this study, we investigated the influence of size on desiccation tolerance in juveniles of the calyptraeid gastropod Crepipatella peruviana to determine the size at which they can first survive exposure to air. Juveniles 2-13 mm long were exposed to 75% or 100% relative humidity for 0.5-6.5 hours. Juveniles smaller than 5 mm in shell length did not survive emersion at 75% relative humidity for even 0.5 hours; surprisingly, most also perished after short exposures to air at 100% relative humidity, suggesting that something other than desiccation stress may also be at play. In marked contrast, 82% of juveniles larger than 6 mm in shell length survived exposure to 75% relative humidity for the full 6.5 hours. In a field survey, no juveniles smaller than 9 mm were found on exposed rock but rather were found only in wet microhabitats. We suggest that the clearly defined size escape from desiccation may reflect a change in gill functioning or a newfound ability to retain water more effectively within the mantle cavity at low tide.

Asunto(s)

Desecación , Gastrópodos/fisiología , Animales , Tamaño Corporal/fisiología , Gastrópodos/crecimiento & desarrollo , Análisis de Supervivencia

RESUMEN

Nerve agents with low volatility such as VX are primarily absorbed through the skin when released during combat or a terrorist attack. The barrier function of the stratum corneum may be compromised during certain stages of development, allowing VX to more easily penetrate through the skin. However, age-related differences in the lethal potency of VX have yet to be evaluated using the percutaneous (pc) route of exposure. Thus, we estimated the 24 and 48 h median lethal dose for pc exposure to VX in male and female rats during puberty and early adulthood. Pubescent, female rats were less susceptible than both their male and adult counterparts to the lethal effects associated with pc exposure to VX possibly because of hormonal changes during that stage of development. This study emphasizes the need to control for both age and sex when evaluating the toxicological effects associated with nerve agent exposure in the rat model.

RESUMEN

Ricin toxin (RT) is an extremely potent toxin derived from the castor bean plant. As a possible bioterrorist weapon, it was categorized as a level B agent in international society. With the growing awareness and concerns of the "white powder incident" in recent years, it is indispensable to develop an effective countermeasure against RT intoxication. In this study we used site-directed mutagenesis and polymerase chain reaction (PCR) techniques to modify the gene of ricin A-chain (RTA). As a result, we have generated a mutated and truncated ricin A-chain (mtRTA) vaccine antigen by E.coli strain. The cytotoxicity assay was used to evaluate the safety of the as-prepared mtRTA antigen, and the results showed that there was no residual toxicity observed when compared to the recombinant RTA (rRTA) or native RT. Furthermore, BALB/c mice were subcutaneously (s.c.) vaccinated with mtRTA 3 times at an interval of 2 weeks, and then the survivals were evaluated after intraperitoneal (i.p.) or intratracheal challenge of RT. The vaccinated mice developed a strong protective immune response that was wholly protective against 40 × LD50 of RT i.p. injection or 20 × LD50 of RT intratracheal spraying. The mtRTA antigen has great potential to be a vaccine candidate for future application in humans.

Asunto(s)

Ricina/inmunología , Ricina/envenenamiento , Vacunas/genética , Vacunas/inmunología , Administración por Inhalación , Animales , Bioterrorismo , Escherichia coli/genética , Escherichia coli/metabolismo , Inmunización Pasiva , Inyecciones Subcutáneas , Dosificación Letal Mediana , Ratones , Ratones Endogámicos BALB C , Mutagénesis Sitio-Dirigida , Pruebas de Neutralización , Plásmidos/genética , Reacción en Cadena de la Polimerasa , Ricina/administración & dosificación , Análisis de Supervivencia , Vacunas/administración & dosificación

RESUMEN

Maize (Zea mays) is a widely cultivated cereal that has been safely consumed by humans and animals for centuries. Transgenic or genetically engineered insect-resistant and herbicide-tolerant maize, are commercially grown on a broad scale. Event TC1507 (OECD unique identifier: DAS-Ø15Ø7-1) or the Herculex®(#) I trait, an insect-resistant and herbicide-tolerant maize expressing Cry1F and PAT proteins, has been registered for commercial cultivation in the US since 2001. A science-based safety assessment was conducted on TC1507 prior to commercialization. The safety assessment addressed allergenicity; acute oral toxicity; subchronic toxicity; substantial equivalence with conventional comparators, as well as environmental impact. Results from biochemical, physicochemical, and in silico investigations supported the conclusion that Cry1F and PAT proteins are unlikely to be either allergenic or toxic to humans. Also, findings from toxicological and animal feeding studies supported that maize with TC1507 is as safe and nutritious as conventional maize. Maize with TC1507 is not expected to behave differently than conventional maize in terms of its potential for invasiveness, gene flow to wild and weedy relatives, or impact on non-target organisms. These safety conclusions regarding TC1507 were acknowledged by over 20 regulatory agencies including United States Environment Protection Agency (US EPA), US Department of Agriculture (USDA), Canadian Food Inspection Agency (CFIA), and European Food Safety Authority (EFSA) before authorizing cultivation and/or food and feed uses. A comprehensive review of the safety studies on TC1507, as well as some benefits, are presented here to serve as a reference for regulatory agencies and decision makers in other countries where authorization of TC1507 is or will be pursued.

Asunto(s)

Plantas Modificadas Genéticamente/efectos adversos , Zea mays/genética , Alimentación Animal/efectos adversos , Animales , Seguridad de Productos para el Consumidor , Inocuidad de los Alimentos , Humanos , Medición de Riesgo , Estados Unidos

RESUMEN

Mcl-1, a pro-survival member of the Bcl-2 protein family, is an attractive target for cancer therapy. We have recently identified the natural product marinopyrrole A (maritoclax) as a novel small molecule Mcl-1 inhibitor. Here, we describe the structure-activity relationship study of pyoluteorin derivatives based on maritoclax. To date, we synthesized over 30 derivatives of maritoclax and evaluated their inhibitory actions and cytotoxicity toward Mcl-1-dependent cell lines. As a result, several functional groups were identified in the pyoluteorin motif that significantly potentiate biological activity. A number of such derivatives, KS04 and KS18, interacted with Mcl-1 in a conserved fashion according to NMR spectroscopy and molecular modeling. KS04 and KS18 induced apoptosis selectively in Mcl-1-dependent but not Bcl-2-dependent K562 cells through selective Mcl-1 down-regulation, and synergistically enhanced apoptosis in combination with ABT-737. Moreover, the intraperitoneal administration of KS18 (10 mg/kg/d) and ABT-737 (20 mg/kg/d) significantly suppressed the growth of ABT-737-resistant HL-60 xenografts in nude mice without apparent toxicity. Overall, we identified the pharmacophore of pyoluteorin derivatives that act as potent and promising Mcl-1 antagonists against Mcl-1-dependent hematological cancers.

Asunto(s)

Apoptosis/efectos de los fármacos , Neoplasias Hematológicas/metabolismo , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Fenoles/farmacología , Pirroles/farmacología , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos , Sinergismo Farmacológico , Femenino , Neoplasias Hematológicas/patología , Humanos , Modelos Moleculares , Conformación Molecular , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/antagonistas & inhibidores , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/química , Fenoles/química , Fenoles/metabolismo , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Proteolisis/efectos de los fármacos , Pirroles/química , Pirroles/metabolismo , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo , Factores de Tiempo , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína Destructora del Antagonista Homólogo bcl-2/metabolismo , Proteína X Asociada a bcl-2/metabolismo

RESUMEN

α-Cypermethrin is a widely used insecticide and, at high doses, induces oxidative stress in mammals. Curcumin is an antioxidant phytochemical commonly used for food coloring and flavoring. We aimed to investigate the effects of continuous dietary exposure to low doses of α-cypermethrin, as is the case in exposed humans, on oxidative stress and its potential prevention by dietary curcumin. Four groups of ten male Wistar rats were ad libitum-fed a control diet or identical diets fortified with α-cypermethrin (350 mg/kg diet), curcumin (1000 mg/kg diet), or α-cypermethrin and curcumin (350 and 1000 mg/kg diet, respectively) for 7 weeks. α-Cypermethrin accumulated in adipose tissues and was detectable in kidney, liver, and brains. Dietary α-cypermethrin did not alter concentrations of malondialdehyde, ascorbic and uric acid, retinol, liver damage markers, or the activities of CAT and SOD, but reduced vitamin E in blood. α-Cypermethrin did not affect malondialdehyde or reduced glutathione concentrations in any of the tissues, but significantly increased glutathione disulfide in kidney and subcutaneous adipose tissue. In conclusion, dietary exposure to small doses of α-cypermethrin did not induce oxidative stress in rats and may be less toxic than exposure to comparable quantities administered as single high doses by gastric intubation.