RESUMO
The metal-organic framework (MOF) [Eu(DPA)(HDPA)] (where DPA is dipicolinic acid) has been previously reported as an efficient marker for gunshot residues (GSRs). Since this marker will be in contact with various shooters, industrial workers, and the environment, however, it is important to identify its toxicity. In this work, the oral and the inhalation acute toxicities of the MOF [Eu(DPA)(HDPA)] (also called R-Marker) were evaluated in young Wistar rats using Guidelines 423 (oral) and 436 (inhalation) from the Organisation for Economic Co-operation and Development (OECD). Animal behavior; body weight, water, and food intake; and organ weight, as well as biochemical parameters were evaluated in both evaluations. For the inhalation test, a concentration of 1 mg·Lair-1·(4 h-1) was reached in a whole-body inhalation chamber. When the respiratory tract was analyzed, it was observed that part of the marker had been swallowed instead of inhaled by the animal. For the oral test, the highest administrated dose was 2000 mg/kg with no sign of toxicity. This marker has been classified in the least toxic category of the Globally Harmonized System (GHS; category 5), with an oral median lethal dose (LD50) of 5000 mg/kg. After the oral administration, the feces of the animals were collected using a metabolic cage. Luminescent feces were present up to 24 h after administration, indicating that the marker had been excreted by the organism without causing intoxication. This study has opened perspectives for drug delivery and toxicity studies, since it enables visual detection of the marker.
RESUMO
The lack of predictivity of animal's models has increased the failure rate of drug candidates. Thus, the reversion of this scenario using preliminary in vitro assays and metabolism prediction can reduce the unnecessary use of animals, as well as predict toxic effects at preclinical and clinical stages. The present study aimed to evaluate safety of four biologically active molecules (RN104, RI78, ICH, PCH) with potential therapeutic applications synthesized in our laboratory. Initially, we used MTT cytotoxicity against A549, H9C2, HepG2, LLC-PK1 and NEURO-2 cell lines. RN104 showed the lowest cytotoxicity and further studies were conducted with it. The neutral red (NR) test was performed according to OECD-129 and then acute toxicity test (OECD-423). According to NR results we administered at 300 mg/kg on animals; however, no toxic effect was observed, while 2,000 mg/kg resulted in the death of one animal per group. After, metabolism prediction studies, performed using both ligand-based and structure-based, suggests three potential metabolites. In silico results suggested that potential metabolites could be fast eliminated and, then, this could be an explanation for lower observed toxicity in in vivo experiments. The results showed limitations of the NR as a predictor of the initial dose for the acute toxicity study, which may be related to metabolism. Therefore, the combination of theoretical and experimental studies is relevant to a general understanding of new molecule's toxicity.
Assuntos
Citotoxinas/farmacologia , Células 3T3 , Células A549 , Animais , Linhagem Celular , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Células Hep G2 , Humanos , Camundongos , Modelos Animais , Vermelho Neutro/metabolismo , Testes de Toxicidade Aguda/métodosRESUMO
The 3D metal-organic framework (MOF) [Eu(BTC)] (where BTC = trimesic acid) was synthesized in 20 min by a microwave-assisted hydrothermal method with a yield of 89%. A structural and spectroscopic study, performed by X-ray diffraction, thermogravimetry, and photoluminescence spectroscopy, showed that this framework has high crystallinity, thermal stability, and luminescence. This MOF had a red-orange luminescence when excited with ultraviolet (UV) radiation (λ = 254 nm) and a high potential for use as a luminescent marker for gunshot residues (GSR). When added to 9 mm nontoxic ammunition, it greatly improved quality of the crime scene investigation, allowing for direct visualization of the luminescent GSR on the shooter's hand and firearm and at the firing range using only a portable UV lamp. The marked luminescent GSR was easily collected and characterized by nondestructive techniques, including with a Video Spectral Comparator and scanning electron microscopy/energy-dispersive spectroscopy, wherein the presence of Eu3+ ions was confirmed. Furthermore, the oral acute toxicity of this MOF was assessed in adult female Wistar rats using the Organisation for Economic Cooperation and Development 423 guidelines. This study classified the MOF [Eu(BTC)] in a less toxic Globally Harmonized System category (category 5), with a LD50 (lethal dose) of 5000 mg/kg, ensuring a wide security range for its application.