Allium cepa as a Toxicogenetic Investigational Tool for Plant Extracts: A Systematic Review.

Toxicological studies are important to investigate the genotoxic effects of various substances. Allium cepa can be used as test model for this purpose. This review summarizes the scope and applications for this A. cepa test model. For this, an up-to-date (April 2023) literature search was made in the Science Direct, PubMed, and Web of Science databases to find published evidence on studies performed using A. cepa as a test model. Out of 3,748 studies, 74 fit the inclusion criteria. The results showed that the use of the test model A. cepa contributed considerably to measuring the toxicological potential of plant extracts, proving the efficacy of the test as a potent bioindicator of toxic effects. In addition, 27 studies used more than one test system to verify the toxicological potential of extracts and fractions. Studies have shown that the A. cepa model has the potential to replace other test systems that make use of animals and cell cultures, besides having other advantages such as low cost, ease of execution, and good conditions for the observation of chromosomes. In conclusion, the A. cepa test can be considered one of the potential biomonitoring systems in toxicological studies of crude extracts.

Antimitotic and toxicogenetic action of Stevia urticifolia aerial parts on proliferating vegetal and mammalian cells: in vitro and in vivo traditional and replacement methods.

Stevia urticifolia Thunb. is an underexploited herb possessing bioactive flavonoids, saponins, and terpenoids. The aim of this study was to examine the antiproliferative and toxicogenetic properties of the ethyl acetate extract from Stevia urticifolia aerial parts (EtAcSur) upon Artemia salina, erythrocytes, Allium cepa and sarcoma 180 cells and fibroblasts, as well as in vivo studies on mice to determine systemic, macroscopic, and behavioral alterations and bone marrow chromosomal damage. The assessment using A. salina larvae and mouse blood cells revealed LC50 and EC50 values of 68.9 and 113.6 µg/ml, respectively. Root growth and mitosis were inhibited by EtAcSur, and chromosomal aberrations were detected only at 100 µg/ml. EtAcSur exhibited potent concentration-dependent viability reduction of S180 and L-929 cells and antioxidant capacity employing ABTS• and DPPH•. No previous in vivo studies were performed before with the EtAcSur. Signals of acute toxicity were not observed at 300 mg/kg. Physiological and toxicological investigations at 25 and 50 mg/mg/day i.p. for 8 days did not markedly change body or organ relative weights, nor patterns of spontaneous locomotor and exploratory activities. In contrast, clastogenic effects on bone marrow were found at 50 mg/mg/day. EtAcSur was found to (1) produce toxicity in microcrustaceans, (2) capacity as free radical scavenger, (3) antimitotic, cytotoxic and clastogenic activties upon vegetal and mammalian cells, and (4) lethality on both tumor and normal murine cells indistinctly. In vivo damage systemic effects were not remarkable and clinical signals of toxicity were not observed, suggesting the significant pharmacological potential of S. urticifolia for the development of antineoplastic agents.Abbreviations: ABTS: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); DMSO: dimethylsulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EC50: effective concentration 50%; EtAcSur: ethyl acetate extract from Stevia urticifolia aerial parts; Hb, hemoglobin; IC50: inhibitory concentration 50%; LC50,: lethal concentration 50%; MI: mitotic index; RBC, red blood cells; Trolox: 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid.

Pharmacological Effects and Toxicogenetic Impacts of Omeprazole: Genomic Instability and Cancer.

Omeprazole (OME) is commonly used to treat gastrointestinal disorders. However, long-term use of OME can increase the risk of gastric cancer. We aimed to characterize the pharmacological effects of OME and to correlate its adverse effects and toxicogenetic risks to the genomic instability mechanisms and cancer-based on database reports. Thus, a search (till Aug 2019) was made in the PubMed, Scopus, and ScienceDirect with relevant keywords. Based on the study objective, we included 80 clinical reports, forty-six in vitro, and 76 in vivo studies. While controversial, the findings suggest that long-term use of OME (5 to 40 mg/kg) can induce genomic instability. On the other hand, OME-mediated protective effects are well reported and related to proton pump blockade and anti-inflammatory activity through an increase in gastric flow, anti-inflammatory markers (COX-2 and interleukins) and antiapoptotic markers (caspases and BCL-2), glycoprotein expression, and neutrophil infiltration reduction. The reported adverse and toxic effects, especially in clinical studies, were atrophic gastritis, cobalamin deficiencies, homeostasis disorders, polyp development, hepatotoxicity, cytotoxicity, and genotoxicity. This study highlights that OME may induce genomic instability and increase the risk of certain types of cancer. Therefore, adequate precautions should be taken, especially in its long-term therapeutic strategies and self-medication practices.