Biosafety Evaluation of 6,7-Dihydroxy-3-(2-Nitrophenyl)Coumarin in Human Cells Júlia Zocca Nunes de Barros, Luma Eduarda Lopes Escalante, Maria João Matos, Edson Luis Maistro Journal of Applied Toxicology, 2026 Coumarins are considered a privileged scaffold in medicinal chemistry, as they may interact with biological macromolecules, presenting several pharmacological properties. Their potential makes them an object of study for the evaluation of their safety for humans, which is essential in the design of a potential drug. 6,7‐Dihydroxy‐3‐(2‐nitrophenyl)coumarin is a synthetic derivative with antioxidant properties, amongst other biological activities under study. The main goal of this study is to evaluate the potential cytotoxic and genotoxic effects of this molecule in peripheral blood mononuclear cells (PBMCs) and human hepatocellular carcinoma cells (HepG2/C3A). The results obtained for the cytotoxicity assays, evaluated by the resazurin assay, using concentrations between 0.1 and 50 μg/mL, showed that there is no decrease in cell viability for both cell lines. Regarding genotoxic assays, the data obtained by the comet assay and the micronucleus test, up to a concentration of 30 μg/mL, did not show significant DNA damage and/or chromosomal mutations for both cell types. Given these results, it can be concluded that 6,7‐dihydroxy‐3‐(2‐nitrophenyl)coumarin, up to a concentration of 30 μg/mL, does not present cytotoxic or genotoxic effects in human cells with and without hepatic metabolism. Considering that this family of coumarins, in general, presents their biological effect at low concentrations (mainly nanomolar range), the results obtained here encourage further studies with this molecule in drug discovery programs. 6,7‐Dihydroxy‐3‐(2‐nitrophenyl)coumarin is a new synthetic derivative with antioxidant properties, amongst other biological activities under study. The main goal of this study was to evaluate the potential cytotoxicity and genotoxicity of this molecule in human cells in vitro. Cytotoxicity assays in concentrations between 0.1 and 50 μg/mL showed no decrease in cell viability. Comet assay and the micronucleus test, up to a concentration of 30 μg/mL, did not show genetic toxicity.
Evaluation of DNA/Chromosome Integrity and Cell Death in Human Metabolically Noncompetent and Competent Cells Exposed to N′-(3,5-Difluorobenzylidene)Pyridine-4-Carbohydrazide Larissa Ribeiro Canuto Santos, Jéssica Natalia Barbosa de Almeida, Camila Cavalleiro Frias, Wanda Pereira Almeida, Edson Luis Maistro Journal of Applied Toxicology, 2026 The N‐acylhydrazone scaffold is recognized as a privileged structure for the design of bioactive substances with increasing applications in medicinal chemistry research. Ensuring the safety of newly developed molecules is a critical step for both human health and environmental protection. Accordingly, this study aimed to evaluate the cytotoxic and genotoxic properties of N ′‐(3,5‐difluorobenzylidene)pyridine‐4‐carbohydrazide in two cellular models: nonmetabolizing leukocytes and metabolically active hepatic cells (HepG2/C3A). The resazurin‐based cytotoxicity analysis, performed with concentrations between 1 and 600 μg/mL, indicated that only the uppermost concentration caused a marked decrease in viability of both cell populations after 48 h of incubation. Regarding genotoxicity at 50, 100, and 200 μg/mL concentrations, no DNA damage was detected in the comet assay, but in the micronucleus test, a significant increase in chromosome alterations in leukocytes at 200 μg/mL concentration was detected, with a decrease in cell proliferation in both cell types. The data indicate that, at the concentrations where the biological effects of acylhydrazone were previously observed, the substance appeared to be safe, but at higher concentrations and/or during chronic exposure, caution and further studies are needed.
Synthetic Strategies for the Development of Novel Heterocycles as Larvicides Targeting Aedes aegypti Linn Thaysnara Batista Brito, Luana Marília Santos Oliveira, Rafaela Karolina Viana Nunes, Edson Luis Maistro, Socrates Cabral de Holanda Cavalcanti Medicinal Chemistry, 2025 Background: Owing to their extensive utilization as pesticides, heterocycles assume a fundamental role in the management of vector-borne diseases. Despite the presence of numerous heterocyclic compounds in commercial insecticides and larvicides, resistance to pesticides still demands novel strategies to current pest control methods. Considering these facts, this review aims to survey the synthesis and SAR of heterocyclic molecules with larvicidal activity against Aedes aegypti Linn Methods: Comprehensive searches across the major databases were conducted to identify heterocyclic compounds exhibiting larvicidal efficacy against Ae. aegypti with the goal to unveil the main characteristics that are essential for exhibiting larvicidal activity Results: Active compounds display LC50 values varying from 0.36 to 2907 μM. Fifteen heterocyclic compounds displayed larvicidal activities below 20 μM. Five-membered ring molecules containing nitrogen and oxygen have displayed larvicidal activity according to the position of heteroatoms in the ring. Molecules bearing 1,2,4-oxadiazole and 1,2-oxazole moieties have been shown to be more active than 1,3,4-oxadiazole derivatives. Compounds possessing the indole scaffold have proven to be more potent than isatin and pyrimidine derivatives. Structural characteristics other than a heterocyclic moiety, such as the presence of halogens and less ionized and polar molecules, may also play a role in determining the final larvicidal activity. Conclusion: The rationale behind this review is to stimulate the discovery of innovative heterocyclic larvicides. Thus, it is important to continue synthesizing new scaffolds to comprehensively elucidate the structure-activity relationship for each heterocyclic moiety outlined in this investigation.
Risk assessment of 2β,3β-19α-trihydroxyursolic acid from Rubus imperialis (Rosaceae) in HepG2/C3A cells via genotoxicity, metabolism, and cell growth Bruna Oshiiwa, Aline Pereira da Silva, Greice Rafaele Alves, Valdir Cechinel Filho, Rivaldo Niero, et al. Journal of Applied Toxicology, 2024 Rubus imperialis (Rosaceae) is a Brazilian medicinal plant that already exhibited therapeutical perspectives. However, previous studies revealed cellular and/or genetic toxicity of extracts from aerial parts of this plant, as well as other species of the Rubus genus. Being 2β,3β‐19α‐trihydroxyursolic acid (2B) one of the major compounds of this plant, with proven pharmacological effect, it is important to investigate the biosafety of this isolated compound. Therefore, in the present study, (2B) was tested by several cytogenotoxic endpoints up to 20 μg/ml in human hepatoma HepG2/C3A cells. The test compound did not produce any decreased cell viability, DNA damage, chromosomal mutations, cell cycle changes, or apoptotic effects in the tested cells. Additionally, RT‐qPCR analysis revealed the downregulation of CYP3A4 (metabolism), M‐TOR (cell death), and CDKN1A (cell cycle) genes. Under the experimental conditions used, the 2B compound did not show cytogenotoxic activity after a single exposure to HepG2/C3A human cells.
Cytogenotoxic screening of the natural compound niga-ichigoside F1 from Rubus imperialis (Rosaceae) Laíza Moura Almeida‐Terassi, Ana Paula Martins Castanha, Greice Rafaele Alves, Valdir Cechinel‐Filho, Rivaldo Niero, et al. Journal of Applied Toxicology, 2024 Rubus imperialis Chum. Schl. (Rosaceae) have demonstrated some pharmacological activities, including gastroprotective action. However, genotoxic effects of R. imperialis extract was also reported. Since niga‐ichigoside F1 (NIF1) is a major compound of this plant species, and which has proven pharmacological properties, it is essential to investigate whether this compound is responsible for the observed toxicity. Therefore, the objective of this study was to analyze the effects of NIF1 on HepG2/C3A cells for possible cytogenotoxicity, cell cycle and apoptosis influence, and expression of genes linked to the DNA damage, cell cycle, cell death, and xenobiotic metabolism. The results showed no cytogenotoxic effects of NIF1 at concentrations between 0.1 and 20 μg/ml. Flow cytometry also showed no cell cycle or apoptosis disturbance. In the gene expression analysis, none of the seven genes investigated showed altered expression. The data indicate that NIF1 has no cytogenotoxic effects, and no interruption of the cell cycle, or induction of apoptosis, apparently not being responsible for the cytotoxic effects observed in the crude extract of R. imperialis.
Evaluation of in vitro cytotoxic and genotoxic effects of the 3-(3,4-dihydroxyphenyl)-8-hydroxycoumarin Edvannia dos Santos Silva, Maria João Matos, Edson Luis Maistro Journal of Applied Toxicology, 2023 A wide variety of natural and synthetic coumarins present therapeutic potential. Therefore, the assessment of their safety for humans is essential. 3‐(3,4‐Dihydroxyphenyl)‐8‐hydroxycoumarin is a coumarin derivative with antioxidant properties, among other biological activities. The aim of this study is to evaluate the cytotoxic and genotoxic potential of this molecule on peripheral blood mononuclear cells (PBMC) and human hepatocellular carcinoma cells (HepG2/C3A). The results obtained for the cytotoxicity assays, evaluated by the trypan blue staining assay, using concentrations between 0.1 and 20 μg/mL, showed that there is no decrease in cell viability for both cell lines. The MTT assay showed a significant decrease in the viability of HepG2/C3A cells at the highest concentrations tested, after 48 h, for all the tested concentrations, after 72 h of exposure. Regarding the genotoxic assays, the data obtained by the comet assay and the micronucleus test, up to the tested concentration of 10 μg/mL, do not show significant DNA damage and/or chromosomal mutations, for both cell lines. However, at the highest tested concentration of 20 μg/mL, a small but significant genotoxic effect was observed in PBMC. In view of the observed results, it can be concluded that the 3‐(3,4‐dihydroxyphenyl)‐8‐hydroxycoumarin, up to a concentration of 10 μg/mL, does not present genotoxic effects in human cells with and without liver enzymes metabolism. Additional studies with higher concentrations of this molecule need to be performed to address its complete biosafety.
Cytogenotoxicity assessment of 3-(3,4-dihydroxyphenyl)-7,8-dihydroxycoumarin on HepG2/C3A cells and leukocytes Ana Paula Martins Castanha, Laíza Moura Almeida‐Terassi, Estela Guardado‐Yordi, Maria João Matos, Edson Luis Maistro Journal of Applied Toxicology, 2023 3‐(3,4‐Dihydroxyphenyl)‐7,8‐dihydroxycoumarin is a newly synthesized coumarin derivative with a potent antioxidant effect. The aim of the present study is to investigate the safety of this compound, determining the in vitro cytotoxic and genotoxic in human peripheral blood mononuclear cells (PBMC) and in HepG2/C3A cells. Cell viability has been investigated by the trypan blue staining test and MTT assay and the genotoxicity by the comet assay and micronucleus test, using concentrations between 0.01 and 10 μg/ml. The compound proved to be noncytotoxic in both cell lines, at all tested concentrations, protecting the cells from the DNA damage. In addition, this molecule does not show clastogenic/aneugenic effects when performing the micronucleus test with cytokinesis blockade. Based on the obtained data, and the conditions of the experiments, we can conclude that the 3‐(3,4‐dihydroxyphenyl)‐7,8‐dihydroxycoumarin is a safe molecule up to a concentration of 10 μg/ml, which encourages further studies aiming to explore its potential as a drug candidate.
In vivo toxicogenic potential of Salix alba (Salicaceae) bark extract Edson Luis Maistro, Peterson Menezes Terrazzas, Alexandra Christinie Helena Frankland Sawaya, Paulo Cesar Pires Rosa, Fábio Ferreira Perazzo, et al. Journal of Toxicology and Environmental Health Part A Current Issues, 2022
